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Sample records for liquid chromatography-electro spray

  1. Structural characterisation of degradation products formed upon di-n-butyl phthalate radiolysis by high-performance liquid chromatography electro-spray tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tintaru, A.; Charles, L. [Univ Aix Marseille 1, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Univ Aix Marseille 2, CNRS, Lab Chim Provence Spectrometries Appl Chim Struct, UMR 6264, F-13397 Marseille (France); Labed, V. [CEA Marcoule, DTCD SPDE L2ED, F-30207 Bagnols Sur Ceze (France)

    2010-07-01

    Complete text of publication follows: Structural characterisation of 15 degradation products, formed upon di-n-butyl phthalate (DBP) radiolysis, has been achieved using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupling. The dissociation behaviour of protonated DBP was first established to be further used to characterise structural deviation in the degradation products. Based on accurate mass measurements, compounds shown by HPLC-MS analysis were all found to be DBP oxidation products, amongst which various sets of isomers could be distinguished. Collision-induced dissociation experiments performed on each electro-sprayed molecule first allowed unambiguous definition of the location of the additional oxygen atoms; that is, in the alkyl branch or on the aromatic ring. Although location of the oxygen atom in the alkyl branches could not always be precisely determined, relative abundances of some product ions allowed oxygenated functions to be identified

  2. Liquid chromatography-mass spectrometry coupling by the intermediary of a liquid micro chromatography-electro spray interface; Couplage chromatographie liquide-spectrometrie de masse par l`intermediaire d`une interface electrospray-microchromatographie liquide

    Energy Technology Data Exchange (ETDEWEB)

    Gillard Factor, C.

    1996-12-06

    The objective of this work is to realize a liquid chromatography- mass spectrometry coupling by the intermediary of an electro spray interface and the evaluation of performances of tis analytical tool to study pollutants in water, and more particularly pesticides whom maximum admissible concentration in a table water is 0.1{mu}g/l. This study has allowed to bring to the fore the interest of the ionization mode by electro spray in a LC/MS coupling to identify and quantify pesticides in the state of traces without treating the sample. Then, it was demonstrated the usefulness of this analytical tool to detect high molecular masses molecules. (N.C.)

  3. Measurements in liquid fuel sprays

    Science.gov (United States)

    Chigier, N.

    1984-01-01

    Techniques for studying the events directly preceding combustion in the liquid fuel sprays are being used to provide information as a function of space and time on droplet size, shape, number density, position, angle of flight and velocity. Spray chambers were designed and constructed for: (1) air-assist liquid fuel research sprays; (2) high pressure and temperature chamber for pulsed diesel fuel sprays; and (3) coal-water slurry sprays. Recent results utilizing photography, cinematography, and calibration of the Malvern particle sizer are reported. Systems for simultaneous measurement of velocity and particle size distributions using laser Doppler anemometry interferometry and the application of holography in liquid fuel sprays are being calibrated.

  4. Dispersiveness of Liquid Droplets Sprayed with Cocurrent Gas Flow

    Directory of Open Access Journals (Sweden)

    Arkhipov Vladimir

    2016-01-01

    Full Text Available Pneumohydraulic stand, equipped with a set of aerosol systems laser diagnostics devices, are presented. The results of experimental measurements of the aerosol liquid-drop size distribution in the ejection nozzle spray pattern are provided.

  5. Ballistic Imaging of Liquid Breakup Processes in Dense Sprays

    Science.gov (United States)

    2009-06-24

    link in CFD models is the description of the breakup process for the liquid fuel spray, especially primary breakup; the process by which a liquid...the near field of a hollow cone spray breaking up into sheets, ligaments and droplets. He doesn’t quote numbers, but it is likely that We is less...approaching 10) in the near field. The hollow cone image presented by Van Dyke was taken with a classical white light shadowgram arrangement. If the

  6. Spraying modes in coaxial jet electrospray with outer driving liquid

    Science.gov (United States)

    Chen, Xiaopeng; Jia, Laibing; Yin, Xiezhen; Cheng, Jiusheng; Lu, Jian

    2005-03-01

    Coaxial jet electrospray is a technique to generate microencapsules, which uses electric forces to create a coaxial microjet from two immiscible liquids. Compound droplets with narrow size distribution are produced after the jet breaks up. In this paper, the spraying modes are investigated experimentally with proper flow rates of the inner and outer liquids. Ethanol/glycerol/tween mixture (outer liquid) and cooking oil (inner liquid) are fed into the gap between outer and inner capillaries and the inner capillary, respectively. The spraying modes presented in our experiments are "dripping mode," "dripping mode in spindle," "cone-jet mode," "pulse mode in cone," and "multijets mode" sequentially, as the applied voltage increases. The region of stable cone-jet mode extends with decrease of the outer liquid flow rate and increase of the inner one. It is found that the spray phenomena are mainly determined by properties of the outer liquid, which is viscous and electric conductive enough. A rudimentary physical model is developed, in which both the viscosity and liquid interface tension are taken into account.

  7. Experimental Study of Liquid Fuel Spray Combustion

    DEFF Research Database (Denmark)

    Westlye, Fredrik Ree

    from cavitating and non-cavitating large bore injectors. The injectors have been specifically machined to isolate the effects of in-nozzle cavitation on the resulting spray and combusting characteristics. Experiments were carried out in an optically accessible constant volume combustion vessel......This PhD dissertation was carried out at the Technical University of Denmark in the Department of Mechanical Engineering and has been supervised by Associate Professor Anders Ivarsson and co-supervised by Professor Jesper Schramm. The project has been a part of the RADIADE project funded...... for camera non-idealities and postprocessing methods have been developed and refined in this work to measure the optical thickness of the soot in the transient spray flames as accurately as possible. The soot cloud from these wide bore injectors was so optically thick that it appeared opaque to the camera...

  8. Spray Characterization of Gas-to-Liquid Synthetic Jet Fuels

    Science.gov (United States)

    Kannaiyan, Kumaran; Sadr, Reza; GTL jet fuel Consortium Team

    2012-11-01

    Gas-to-Liquid (GTL) Synthetic Paraffinic Kerosene (SPK) fuel obtained from Fischer-Tropsch synthesis has grabbed the global attention due to its cleaner combustion characteristics. GTL fuels are expected to meet the vital qualities such as atomization, combustion and emission characteristics of conventional jet fuels. It is imperative to understand fuel atomization in order to gain insights on the combustion and emission aspects of an alternative fuel. In this work spray characteristics of GTL-SPK, which could be used as a drop-in fuel in aircraft gas turbine engines, is studied. This work outlines the spray experimental facility, the methodology used and the results obtained using two SPK's with different chemical compositions. The spray characteristics, such as droplet size and distribution, are presented at three differential pressures across a simplex nozzle and compared with that of the conventional Jet A-1 fuel. Experimental results clearly show that although the chemical composition is significantly different between SPK's, the spray characteristics are not very different. This could be attributed to the minimal difference in fluid properties between the SPK's. Also, the spray characteristics of SPK's show close resemblance to the spray characteristics of Jet A-1 fuel.

  9. Gas-Liquid Supersonic Cleaning and Cleaning Verification Spray System

    Science.gov (United States)

    Parrish, Lewis M.

    2009-01-01

    NASA Kennedy Space Center (KSC) recently entered into a nonexclusive license agreement with Applied Cryogenic Solutions (ACS), Inc. (Galveston, TX) to commercialize its Gas-Liquid Supersonic Cleaning and Cleaning Verification Spray System technology. This technology, developed by KSC, is a critical component of processes being developed and commercialized by ACS to replace current mechanical and chemical cleaning and descaling methods used by numerous industries. Pilot trials on heat exchanger tubing components have shown that the ACS technology provides for: Superior cleaning in a much shorter period of time. Lower energy and labor requirements for cleaning and de-scaling uper.ninih. Significant reductions in waste volumes by not using water, acidic or basic solutions, organic solvents, or nonvolatile solid abrasives as components in the cleaning process. Improved energy efficiency in post-cleaning heat exchanger operations. The ACS process consists of a spray head containing supersonic converging/diverging nozzles, a source of liquid gas; a novel, proprietary pumping system that permits pumping liquid nitrogen, liquid air, or supercritical carbon dioxide to pressures in the range of 20,000 to 60,000 psi; and various hoses, fittings, valves, and gauges. The size and number of nozzles can be varied so the system can be built in configurations ranging from small hand-held spray heads to large multinozzle cleaners. The system also can be used to verify if a part has been adequately cleaned.

  10. Vacuum plasma spray applications on liquid fuel rocket engines

    Science.gov (United States)

    Mckechnie, T. N.; Zimmerman, F. R.; Bryant, M. A.

    1992-01-01

    The vacuum plasma spray process (VPS) has been developed by NASA and Rocketdyne for a variety of applications on liquid fuel rocket engines, including the Space Shuttle Main Engine. These applications encompass thermal barrier coatings which are thermal shock resistant for turbopump blades and nozzles; bond coatings for cryogenic titanium components; wear resistant coatings and materials; high conductivity copper, NaRloy-Z, combustion chamber liners, and structural nickel base material, Inconel 718, for nozzle and combustion chamber support jackets.

  11. Effects of self-pulsation on the spray characteristics of gas-liquid swirl coaxial injector

    Science.gov (United States)

    Kang, Zhongtao; Li, Qinglian; Cheng, Peng; Zhang, Xinqiao; Wang, Zhen-guo

    2016-10-01

    To understand the influence of self-pulsation on the spray characteristics of gas-liquid swirl coaxial injector, a back-lighting photography technique has been employed to capture the instantaneous self-pulsated spray and stable spray images with a high speed camera. The diameter and velocity of the droplets in the spray have been characterized with a Dantec Phase Doppler Anemometry (PDA) system. The effects of self-pulsation on the spray pattern, primary breakup, spray angle, diameter and velocity distribution and mass flow rate distribution are analyzed and discussed. The results show that the spray morphology is greatly influenced by self-pulsation. The stable spray has a cone shape, while the self-pulsated spray looks like a Christmas tree. The main difference of these two sprays is the primary breakup. The liquid film of stable spray keeps stable while that of self-pulsated spray oscillates periodically. The film width of self-pulsated spray varies in a large range with 'neck' and 'shoulder' features existing. The liquid film of self-pulsated spray breaks up at the second neck, and then the second shoulder begins to breakup into ligaments. The self-pulsated spray produces droplet clusters periodically, varies horizontal spray width and mass flux periodically. From the point of spatial distribution, self-pulsation is good for the spray, it uniformizes the mass flux along radius and increases the spray angle. However, when self-pulsation occurs, the SMD distribution varies from an inverted V shape to a hollow cone shape, and SMD increases at all the measuring points. Namely, from the point of atomization performance, self-pulsation has negative effects even when the breakup length is smaller. The effects of self-pulsation on the diameter and velocity distributions of the spray are mainly in the center part of the spray. The periphery of stable and self-pulsated spray has similar diameter and velocity distribution.

  12. Experimental characterisation of sprays resulting from impacts of liquid-containing projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Hostikka, Simo, E-mail: simo.hostikka@aalto.fi [Aalto University, Espoo (Finland); Silde, Ari; Sikanen, Topi; Vepsä, Ari; Paajanen, Antti [VTT Technical Research Centre of Finland Ltd, Espoo (Finland); Honkanen, Markus [Pixact Oy, Tampere (Finland)

    2015-12-15

    Highlights: • Detailed characterisation of sprays resulting from the impacts of water-filled metal projectiles on a hard wall. • Experimental measurements of spray speed, direction and droplet size. • Detailed analysis of overall spray evolution. • The spray characterisation information can be used in CFD analyses of aircraft impact fires. - Abstract: Modelling and analysing fires following aircraft impacts requires information about the behaviour of liquid fuel. In this study, we investigated sprays resulting from the impacts of water-filled metal projectiles on a hard wall. The weights of the projectiles were in the range of 38–110 kg, with 8.6–68 kg water, and the impact speeds varied between 96 and 169 m/s. The overall spray behaviour was observed with high-speed video cameras. Ultra-high-speed cameras were used in backlight configuration for measuring the droplet size and velocity distributions. The results indicate that the liquid leaves the impact position as a thin sheet of spray in a direction perpendicular to the projectile velocity. The initial spray speeds were 1.5–2.5 times the impact speed, and the Sauter mean diameters were in the 147–344 μm range. This data can be used as boundary conditions in CFD fire analyses, considering the two-phase fuel flow. The overall spray observations, including the spray deceleration rate, can be used for validating the model.

  13. High Fidelity Tool for Turbulent Combustion in Liquid Launch Propulsion Systems Based on Spray-Flamelet Methodology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation proposed here is a high-performance, high-fidelity simulation capability for simulating liquid rocket spray combustion based on a novel spray-flamelet...

  14. Experimental Study on the Interaction of Fine Water Spray with Liquid Pool Fires

    Institute of Scientific and Technical Information of China (English)

    Guangxuan Liao; Jianghong Liu; Jun Qin; Bin Yao

    2001-01-01

    An experimental study of the interaction of a fine water spray with liquid pool fires was performed.Spatially resolved droplet size, velocity distributions, and volume flux of the fine water spray have been obtained in two types of pressure-atomized fine spray, using LDA/APV technology. A method to correct for the presence of droplets is presented and used to determine the heat release rate using a cone calorimeter system, the effects of water spray application on the beat release rate for liquid pool fires were studied. It was found that the volume flux of the water spray is an important factor to determine the liquid pool fire behavior. For the current experimental conditions, the flame was enlarged when lower volume flux of water is used, and suppressed significantly when larger volumes of water are used. Two opposing mechanisms compete when water sprays are applied, which is more complex than the halon agents, such as 1301. The combustion enhancement becomes insignificant when water sprays with the proper characteristics such as adequate volume flux are applied to the diffusion flame in a confined space.

  15. Effects of momentum ratio and Weber number on spray half angles of liquid controlled pintle injector

    Science.gov (United States)

    Son, Min; Yu, Kijeong; Koo, Jaye; Kwon, Oh Chae; Kim, Jeong Soo

    2015-02-01

    A pintle injector is advantageous for throttling a liquid rocket engine and reducing engine weight. This study explores the effects of momentum ratio and Weber number at various injection conditions on spray characteristics of the pintle injector for liquid-gas propellants. A liquid sheet is injected from a center pintle nozzle and it is broken by a gas jet from an annular gap. The pressure drops of propellants, and the pintle opening distance were considered as control variables; using 0.1 ˜1.0 as a bar for the pressure drop of the liquid injection, a 0.01˜0.2 bar for the pressure drop of gas jet and a 0.2˜ 1.0 mm for the pintle opening distance. The discharge coefficient was decreased linearly before the pintle opening distance of 0.75 mm and then, the coefficient was slightly increased. Spray images were captured by a CMOS camera with high resolution. Then, the shadow and reflected images were analyzed. Spray distributions were measured by a patternator with an axial distance of 50 mm from a pintle tip. Finally, the spray half angles had an exponentially decreasing correlation as a momentum ratio divided by the Weber number. Also, the spray half angles from the spray distribution were underestimated compared to those measured from the captured images.

  16. Effect of liquid retentate storage on flavor of spray-dried whey protein concentrate and isolate.

    Science.gov (United States)

    Whitson, M; Miracle, R E; Bastian, E; Drake, M A

    2011-08-01

    The objective of this study was to determine the effects of holding time of liquid retentate on flavor of spray-dried whey proteins: Cheddar whey protein isolate (WPI) and Mozzarella 80% whey protein concentrate (WPC80). Liquid WPC80 and WPI retentate were manufactured and stored at 3°C. After 0, 6, 12, 24, and 48h, the product was spray-dried (2kg) and the remaining retentate held until the next time point. The design was replicated twice for each product. Powders were stored at 21°C and evaluated every 4 mo throughout 12 mo of storage. Flavor profiles of rehydrated proteins were documented by descriptive sensory analysis. Volatile components were analyzed with solid phase microextraction coupled with gas chromatography mass spectrometry. Cardboard flavors increased in both spray-dried products with increased retentate storage time and cabbage flavors increased in WPI. Concurrent with sensory results, lipid oxidation products (hexanal, heptanal, octanal) and sulfur degradation products (dimethyl disulfide, dimethyl trisulfide) increased in spray-dried products with increased liquid retentate storage time, whereas diacetyl decreased. Shelf stability was decreased in spray-dried products from longer retentate storage times. For maximum quality and shelf life, liquid retentate should be held for less than 12h before spray drying.

  17. NUMERICAL SIMULATION OF CHARGED GAS-LIQUID TWO PHASE JET FLOW IN ELECTROSTATIC SPRAYING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Multi-fluid k-ε-kp two phase turbulence model is used to simulate charged gas-liquid two phase coaxial jet, which is the transorting flow field in electrostatic spraying. Compared with the results of experiment, charged gas-liquid twophase turbulence can be well predicted by this model.

  18. Bioactive Glass-Ceramic Coatings Synthesized by the Liquid Precursor Plasma Spraying Process

    Science.gov (United States)

    Xiao, Yanfeng; Song, Lei; Liu, Xiaoguang; Huang, Yi; Huang, Tao; Chen, Jiyong; Wu, Yao; Wu, Fang

    2011-03-01

    In this study, the liquid precursor plasma spraying process was used to manufacture P2O5-Na2O-CaO-SiO2 bioactive glass-ceramic coatings (BGCCs), where sol and suspension were used as feedstocks for plasma spraying. The effect of precursor and spray parameters on the formation and crystallinity of BGCCs was systematically studied. The results indicated that coatings with higher crystallinity were obtained using the sol precursor, while nanostructured coatings predominantly consisting of amorphous phase were synthesized using the suspension precursor. For coatings manufactured from suspension, the fraction of the amorphous phase increased with the increase in plasma power and the decrease in liquid precursor feed rate. The coatings synthesized from the suspension plasma spray process also showed a good in vitro bioactivity, as suggested by the fast apatite formation when soaking into SBF.

  19. Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

    Directory of Open Access Journals (Sweden)

    Qiang WEI

    2017-08-01

    Full Text Available To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray, the conventional uncoupled spray model for impinging injectors is extended by considering the coupling of the jet impingement process and the ambient gas field. The new coupled model consists of the plain-orifice sub-model, the jet-jet impingement sub-model and the droplet collision sub-model. The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions. The overall model is benchmarked under various impingement angles, jet momentum and off-center ratios. Agreement with the published experimental data validates the ability of the model to predict the key spray characteristics, such as the mass flux and mixture ratio distributions in quiescent air. Besides, impinging sprays under changing ambient pressure and non-uniform gas flow are investigated to explore the effect of liquid rocket engine chamber conditions. First, a transient impingement spray during engine start-up phase is simulated with prescribed pressure profile. The minimum average droplet diameter is achieved when the orifices work in cavitation state, and is about 30% smaller than the steady single phase state. Second, the effect of non-uniform gas flow produces off-center impingement and the rotated spray fan by 38°. The proposed model suggests more reasonable impingement spray characteristics than the uncoupled one and can be used as the first step in the complex simulation of coupling impingement spray and combustion in liquid rocket engines.

  20. Novel Techniques for Quantification of Correlation Between Primary Liquid Jet Breakup and Downstream Spray Characteristics

    Science.gov (United States)

    2016-10-05

    rely on air-blast atomizers in order to generate appropriate fuel spray characteristics for the combustion process. In general , such fuel injectors are...droplets based on characteristic time of the large scale turbulent for the three droplet classes were 0.005, 0.01, 0.02 for axial location Z = 0 mm, and...AFRL-AFOSR-JP-TR-2016-0084 Novel techniques for quantification of correlation between primary liquid jet breakup and downstream spray characteristics

  1. Calculation of a hollow-cone liquid spray in a uniform air stream

    Science.gov (United States)

    Sturgess, G. J.; Syed, S. A.; McManus, K. R.

    1984-06-01

    Fluid dynamic computer codes for the simulation of flows in gas turbine engine combustion systems are being developed. NASA is currently sponsoring a two-phase program for the evaluation of the performance of current codes, taking into account also an improvement of accuracy, if needed. The present investigation forms a part of this program. The numerical technique used includes a Lagrangian spray model for liquid fuels. The spray model, in conjunction with the turbulence model, determines the distribution of fuel in the burning zone of the combustor. The numerical technique was applied to a hollow-cone pressure atomizer spraying water into a coflowing confined airstream.

  2. Estimation of the diameter-charge distribution in polydisperse electrically charged sprays of electrically insulating liquids

    Science.gov (United States)

    Rigit, A. R. H.; Shrimpton, John S.

    2009-06-01

    The majority of scientific and industrial electrical spray applications make use of sprays that contain a range of drop diameters. Indirect evidence suggests the mean drop diameter and the mean drop charge level are usually correlated. In addition, within each drop diameter class there is every reason to suspect a distribution of charge levels exist for a particular drop diameter class. This paper presents an experimental method that uses the joint PDF of drop velocity and diameter, obtained from phase Doppler anemometry measurements, and directly obtained spatially resolved distributions of the mass and charge flux to obtain a drop diameter and charge frequency distribution. The method is demonstrated using several data-sets obtained from experimental measurements of steady poly-disperse sprays of an electrically insulating liquid produced with the charge injection technique. The space charge repulsion in the spray plume produces a hollow cone spray structure. In addition an approximate self-similarity is observed, with the maximum radial mass and charge flow occurring at r/ d ~ 200. The charge flux profile is slightly offset from the mass flux profile, and this gives direct evidence that the spray specific charge increases from approximately 20% of the bulk mean spray specific charge on the spray axis to approximately 200% of the bulk mean specific charge in the periphery of the spray. The results from the drop charge estimation model suggest a complex picture of the correlation between drop charge and drop diameter, with spray specific charge, injection velocity and orifice diameter all contributing to the shape of the drop diameter-charge distribution. Mean drop charge as a function of the Rayleigh limit is approximately 0.2, and is invariant with drop diameter and also across the spray cases tested.

  3. Effect of Flame Conditions on Crystalline Structure of TiO2 in Liquid Flame Spraying

    Institute of Scientific and Technical Information of China (English)

    LI Chang-jiu; YANG Guan-jun; WANG Yu-yue

    2004-01-01

    Nanostructured TiO2 is a most promising functional ceramic owing to its potential utilization in photocatalytical, optical and electrical applications. Nanostructured TiO2 coating was deposited through thermal spraying with liquid feedstock. Two types of crystalline structures were present in the synthesized TiO2 coating including anatase phase and rutile phase.The effect of spray flame conditions on the crystalline structure was investigated in order to control the crystalline structure of the coating. The results showed that spray distance, flame power and precursor concentration in the liquid feedstock significantly influenced phase constitutions and grain size in the coating. Anatase phase was formed at spray distance from 150 to 250mm, while rutile phase was evidently observed in the coating deposited at 100 mm. The results suggested that anatase phase was firstly formed in the coating, and rutile phase resulted from the transformation of the deposited anatase phase. The phase transformation from anatase to rutile occurred through the annealing effect of spraying flame. The control of the phase formation can be realized through flame condition and spray distance.

  4. Novel method for the measurement of liquid film thickness during fuel spray impingement on surfaces.

    Science.gov (United States)

    Henkel, S; Beyrau, F; Hardalupas, Y; Taylor, A M K P

    2016-02-01

    This paper describes the development and application of a novel optical technique for the measurement of liquid film thickness formed on surfaces during the impingement of automotive fuel sprays. The technique makes use of the change of the light scattering characteristics of a metal surface with known roughness, when liquid is deposited. Important advantages of the technique over previously established methods are the ability to measure the time-dependent spatial distribution of the liquid film without a need to add a fluorescent tracer to the liquid, while the measurement principle is not influenced by changes of the pressure and temperature of the liquid or the surrounding gas phase. Also, there is no need for non-fluorescing surrogate fuels. However, an in situ calibration of the dependence of signal intensity on liquid film thickness is required. The developed method can be applied to measure the time-dependent and two-dimensional distribution of the liquid fuel film thickness on the piston or the liner of gasoline direct injection (GDI) engines. The applicability of this technique was evaluated with impinging sprays of several linear alkanes and alcohols with different thermo-physical properties. The surface temperature of the impingement plate was controlled to simulate the range of piston surface temperatures inside a GDI engine. Two sets of liquid film thickness measurements were obtained. During the first set, the surface temperature of the plate was kept constant, while the spray of different fuels interacted with the surface. In the second set, the plate temperature was adjusted to match the boiling temperature of each fuel. In this way, the influence of the surface temperature on the liquid film created by the spray of different fuels and their evaporation characteristics could be demonstrated.

  5. Metered Cryospray™: a novel uniform, controlled, and consistent in vivo application of liquid nitrogen cryogenic spray

    Science.gov (United States)

    Mulcahey, Thomas I; Coad, James E; Fan, Wei Li; Grasso, Daniel J; Hanley, Brian M; Hawkes, Heather V; McDermott, Sean A; O’Connor, John P; Sheets, Ellen E; Vadala, Charles J

    2017-01-01

    In this article, a novel cryotherapy approach using a uniform, controlled, and consistent in vivo application of liquid nitrogen (LN2) spray as a Metered Cryospray™ (MCS) process is described. Although MCS may be used for many potential clinical applications, this paper focuses on the development that led to the controlled and consistent delivery of radial LN2 cryogen spray in order to generate a uniform circumferential effect and how the amount of MCS can be adapted to specifically ablate targeted diseases within a patient’s lumen such as an airway or esophagus. PMID:28255257

  6. Effect of Spray Drying Technique on Processing of Stropharia rugoso-annulata Farl: Murrill Blanching Liquid

    Directory of Open Access Journals (Sweden)

    Junchen Chen

    2014-04-01

    Full Text Available Blanching liquid from processing of Stropharia rugoso-annulata fruits were traditionally discarded as bio-waste although it contains certain amount of soluble nutrients. The discarding may result not only in environment pollution but also in loss of valuable mushroom nutrients. In this study, spray drying technique was applied to process the liquid; and the processing factors were optimized with Response Surface Methodology. The results showed that the factors on Inlet Air Temperature, Atomization Pressure and Total Soluble Solid Content were for 172C, 920 bar and 15%, respectively, with the best spray drying efficiency for 60.26%. The products were estimated for the proper storage conditions based on the free radical scavenging activity for •OH. The results indicated that the storage temperature, lights and packaging are important for the products in maintaining their scavenging activity and the proper conditions to preserve the spray drying powder lasted for 60 days were at 0C, no lights and with packaged. It is suggested that spray drying technique may play effectively for processing of any mushroom blanching liquid and the darkness and dryness are crucial for the drying powder preservation.

  7. Charge generation associated with liquid spraying in tank cleaning and comparable processes - preliminary experiments

    Science.gov (United States)

    Blum, Carsten; Losert, Oswald F. J.

    2015-10-01

    The BG RCI has initiated investigations in order to improve the data basis for assessing the ignition hazard by electrostatic charging processes associated with the spraying of liquids. On the base of preliminary experiments, we established procedures for measurements of electric field strength and charging current in the presence of aerosol particles. Results obtained with three different nozzle types, variation of pressure and with built-in deflecting plate are presented.

  8. The influence of cavitation on the flow characteristics of liquid nitrogen through spray nozzles: A CFD study

    Science.gov (United States)

    Xue, Rong; Ruan, Yixiao; Liu, Xiufang; Cao, Feng; Hou, Yu

    2017-09-01

    Spray cooling with cryogen could achieve lower temperature level than refrigerant spray. The internal flow conditions within spray nozzles have crucial impacts on the mass flow rate, particle size, spray angle and spray penetration, thereby influencing the cooling performance. In this paper, CFD simulations based on mixture model are performed to study the cavitating flow of liquid nitrogen in spray nozzles. The cavitation model is verified using the experimental results of liquid nitrogen flow over hydrofoil. The numerical models of spray nozzle are validated against the experimental data of the mass flow rate of liquid nitrogen flow through different types of nozzles including the pressure swirl nozzle and the simple convergent nozzle. The numerical studies are performed under a wide range of pressure difference and inflow temperature, and the vapor volume fraction distribution, outlet vapor quality, mass flow rate and discharge coefficient are obtained. The results show that the outlet diameter, the pressure difference, and the inflow temperature significantly influence the mass flow rate of spray nozzles. The increase of the inflow temperature leads to higher saturation pressure, higher cavitation intensity, and more vapor at nozzle outlet, which can significantly reduce mass flow rate. While the discharge coefficient is mainly determined by the inflow temperature and has little dependence on the pressure difference and outlet diameter. Based on the numerical results, correlations of discharge coefficient are proposed for pressure swirl nozzle and simple convergent nozzles, respectively, and the deviation is less than 20% for 93% of data.

  9. Characterization of the liquid sodium spray generated by a pipework hole

    Energy Technology Data Exchange (ETDEWEB)

    Torsello, G.; Parozzi, F.; Nericcio, L. [RSE - Nuclear and Industrial Plant Safety Team, Power Generation System Dept., via Rubattino 54, 20134 Milano (Italy); Araneo, L.; Cozzi, F. [Politecnico di Milano, Energy Dept., via Lambruschini 4, 20156 Milano (Italy); Carcassi, M.; Mattei, N. [Universita di Pisa-Facolta d' Ingegneria DIMNP-Mechanical, Nuclear and Production Dep., Largo L. Lazzarino 2, 56126 Pisa (Italy)

    2012-07-01

    Due to its advantageous thermodynamic characteristics at high temperature (550 deg. C), liquid sodium is the main candidate to be the cooling fluid for Generation TV nuclear reactors SFR (Sodium-cooled Fast Reactors). Now, sodium reacts very violently, both with the water and the oxygen of the air. Only few data were known about the liquid sodium behaviour when spread in the environment through micro defects. These are often present in a cooling circuit in welded or sealed joints and more rarely in the pipes. Micro defects, on the other hand, can be also generated in a cooling circuit because of the vibrations always present in a circuit into which a fluid runs. A new set-up, named LISOF, was built for testing high temperature liquid sodium when passing through micro defects and generating sprays or jets. Sprays and jets were generated by means of nozzles embedding sub milli-metric holes the diameter of which was: 0.2 mm, 0.4 mm, 0.5 mm. Tests were performed by pressurizing liquid sodium (550 deg. C) at: 3, 6 and 9 barg. Normal and high speed cinematography were used for the direct observation of the liquid sodium sprays while Phase Doppler Interferometry was used for the measurement of the droplets characteristics and velocity. Tests concerning the behaviour of the high temperature liquid sodium firing in air or in contact with the cement cover applied to a scaled down core catcher simulacrum were also performed. The paper presents the built set-up and the collected results. (authors)

  10. Electro-spray of high viscous liquids for producing mono-sized spherical alginate beads

    Institute of Scientific and Technical Information of China (English)

    Hamid Moghadam; Mohsen Samimi; Abdolreza Samimi; Mohamad Khorram

    2008-01-01

    Alginate beads, often used for controlled release of enzymes and drugs, are usually produced by spraying sodium alginate liquid into a gelling agent using mechanical vibration nozzle or air jet. In this work an alternative method of electro-spray was employed to form droplets with desired size from a highly viscous sodium alginate solution using constant DC voltage. The droplets were then cured in a calcium chloride solution. The main objective was to produce mono-sized beads from such a highly viscous and non-Newtonian liquid (1000-5000 mPa s). The effects of nozzle diameter, flow rate and concentration of liquid on the size of the beads were investigated. Among the parameters studied, voltage had a pronounced effect on the size of beads as compared to flow rate zzle diameter and concentration of alginate liquid. The size of beads was reduced to a minimum value with increasing the voltage in the range of 0-10 kV. At the early stages of voltage increase (I.e. Up to about 4 kV), the rate of size reduction was relatively low, while the dripping mode dominated. However, in the middle part of the range of applied voltage, where the rate of size reduction was high (I.e. About 4-7 kV), an unstable transition occurred between dripping and jetting. At the end part of the range (I.e. 7-10 kV) jet mode of spray was observed. Increasing the height of fall of the droplets was found to improve the sphericity of the beads, because of the increased time of flight for the droplets. This was especially identifiable at higher concentrations of the alginate liquid (I.e. 3 w/v%)

  11. Verification on spray simulation of a pintle injector for liquid rocket engine

    Science.gov (United States)

    Son, Min; Yu, Kijeong; Radhakrishnan, Kanmaniraja; Shin, Bongchul; Koo, Jaye

    2016-02-01

    The pintle injector used for a liquid rocket engine is a newly re-attracted injection system famous for its wide throttle ability with high efficiency. The pintle injector has many variations with complex inner structures due to its moving parts. In order to study the rotating flow near the injector tip, which was observed from the cold flow experiment using water and air, a numerical simulation was adopted and a verification of the numerical model was later conducted. For the verification process, three types of experimental data including velocity distributions of gas flows, spray angles and liquid distribution were all compared using simulated results. The numerical simulation was performed using a commercial simulation program with the Eulerian multiphase model and axisymmetric two dimensional grids. The maximum and minimum velocities of gas were within the acceptable range of agreement, however, the spray angles experienced up to 25% error when the momentum ratios were increased. The spray density distributions were quantitatively measured and had good agreement. As a result of this study, it was concluded that the simulation method was properly constructed to study specific flow characteristics of the pintle injector despite having the limitations of two dimensional and coarse grids.

  12. Numerical simulation of the two-phase flow produced by spraying a liquid by a nozzle

    Science.gov (United States)

    Simakov, N. N.

    2017-07-01

    A numerical experiment on the simulation of the two-phase flow formed during spraying of a liquid by a nozzle has been described. The radial and axial velocity profiles of the droplets and gas in the free spray and in the two-phase flow through a cylindrical apparatus have been calculated and represented taking into account the early drag crisis of droplets and peculiarities of turbulent friction in the gas, which was detected in previous experiments. The distinguishing feature of the numerical model of the two-phase flow is that it employs the differential equations describing the nonstationary flow of a compressible gas as the initial equations. In transition to their difference analog, the familiar Lax-Wendorff algorithm has been used. A comparison of the results of calculations based on this model with experimental data has demonstrated their concordance.

  13. Spray Formation of a Liquid Carbon Dioxide-Water Mixture at Elevated Pressures

    Directory of Open Access Journals (Sweden)

    Hakduck Kim

    2016-11-01

    Full Text Available Liquid carbon dioxide-assisted (LCO2-assisted atomization can be used in coal-water slurry gasification plants to prevent the agglomeration of coal particles. It is essential to understand the atomization behavior of the water-LCO2 mixture leaving the injector nozzle under various conditions, including the CO2 blending ratio, injection pressure, and chamber pressure. In this study, the flash-atomization behavior of a water-LCO2 mixture was evaluated with regard to the spray angle and penetration length during a throttling process. The injector nozzle was mounted downstream of a high-pressure spray-visualization system. Based on the results, the optimal condition for the effective transport of coal particles was proposed.

  14. Sprinkler and water spray techniques in fires of combustible liquids. Sprinkleritekniikka nestepaloissa

    Energy Technology Data Exchange (ETDEWEB)

    Keski-Rahkonen, O.

    1986-08-15

    The purpose of this review is to find out what is known scientifically about extinguishment and control of fires in combustible liquids by sprinkler and water spray techniques. Because no review on combustion is available in Finnish, the first part of the study deals extensively with principles and the most important parameters of combustion of liquids in different geometries. The theory of flames based on diffusion equations is outlined both for laminar and turbulent flow. Then the application of these theories on pool fire and droplet burning are described. The theoretical extinction criteria were studied to find out the essential factors controlling the extinguishment process. The movement of water droplets in and interactions with flames is approached theoretically and experimentally. The latter part of the study presents the most important sprinkler test series since the fifties. It gives a simple theory on sprinkler actuation time and describes test series designed to find out practical answers to the required water flux density. Most of the tests deal with pool fire of combustible liquids. The extinguishment of a gas blow out fire and a number of tests using solid fuels are also included. The fires and the protection by water spray cooling of the storage tanks and pressure vessels are reviewed. Finally, the development of early-suppression, fast-response (ESFR) and intelligent sprinkler systems is described briefly.

  15. Iron Oxide Doped Alumina-Zirconia Nanoparticle Synthesis by Liquid Flame Spray from Metal Organic Precursors

    OpenAIRE

    Juha-Pekka Nikkanen; Helmi Keskinen; Mikko Aromaa; Mikael Järn; Tomi Kanerva; Erkki Levänen; Mäkelä, Jyrki M.; Tapio Mäntylä

    2008-01-01

    The liquid flame spray (LFS) method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K) H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical compositi...

  16. Liquid Feedstock Plasma Spraying: An Emerging Process for Advanced Thermal Barrier Coatings

    Science.gov (United States)

    Markocsan, Nicolaie; Gupta, Mohit; Joshi, Shrikant; Nylén, Per; Li, Xin-Hai; Wigren, Jan

    2017-08-01

    Liquid feedstock plasma spraying (LFPS) involves deposition of ultrafine droplets of suspensions or solution precursors (typically ranging from nano- to submicron size) and permits production of coatings with unique microstructures that are promising for advanced thermal barrier coating (TBC) applications. This paper reviews the recent progress arising from efforts devoted to development of high-performance TBCs using the LFPS approach. Advancements in both suspension plasma spraying and solution precursor plasma spraying, which constitute the two main variants of LFPS, are presented. Results illustrating the different types of the microstructures that can be realized in LFPS through appropriate process parameter control, model-assisted assessment of influence of coating defects on thermo-mechanical properties and the complex interplay between pore coarsening, sintering and crystallite growth in governing thermal conductivity are summarized. The enhancement in functional performances/lifetime possible in LFPS TBCs with multilayered architectures and by incorporating new pyrochlore chemistries such as gadolinium zirconate, besides the conventional single 8 wt.% yttria-stabilized zirconia insulating ceramic layer, is specifically highlighted.

  17. Application of Liquid Flame Spray in single and multicomponent nanoparticle synthesis and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Aromaa, M.

    2012-07-01

    Nanosized materials are interesting because of the unique properties that can only be achieved in nanoscale. The Liquid Flame Spray is an aerosol method for nanoparticle synthesis. The nanoparticles are synthesized from liquid precursor material in a high-temperature, hydrogen-oxygen flame. The aerosol processes in the flame determine the particle size and morphology of the end product. The process parameters used in the synthesis have an effect on the final product. The Liquid Flame Spay process has been utilized in several applications. This thesis deals with the synthesis of nanoparticles with the Liquid Flame Spray and tuning the particle properties. The fundamentals of the aerosol synthesis are discussed first and the process parameters and their effect on the nanoparticles that are synthesized are explained. Later on, the understanding of the process parameters is utilized and the multi-component aerosols are synthesized for various applications and even deposited directly on a substrate to form a functional coating. Titanium dioxide is mainly used in all the papers that are included in the thesis. In addition, other ceramic materials, such as, aluminium oxide and zirconium oxide are synthesized. Dopants, such as, silver are introduced into the product in order to create multifunctional properties. At the moment, the Liquid Flame Spray synthesis is performed in an open atmosphere and therefore the nanoparticles that are synthesized are mainly oxides with the exception of noble metals, e.g. gold, silver palladium and platinum. However, the ceramic particles such as titanium dioxide have interesting properties. Already several decades ago, titanium dioxide was discovered to have photoactive properties, meaning that when excited with UV-light, an electron-hole pair is formed in the titanium dioxide. The process leads to the formation of reactive oxygen and OH-groups on the surface of the material. The reactive oxygen is able to degrade organic molecules leaving

  18. Experimental analysis on the influence of nozzle geometry over the dispersion of liquid n-dodecane sprays

    Directory of Open Access Journals (Sweden)

    Raul ePayri

    2015-10-01

    Full Text Available Understanding and controlling mixing and combustion processes is fundamental in order to face the challenges set by the ever more demanding pollutant regulations and fuel consumption standards of direct injection diesel engines. The fundamentals of these processes haven been long studied by the diesel spray community from both experimental and numerical perspectives. However, certain topics such as the influence of nozzle geometry over the spray atomization, mixing and combustion process are still not completely well understood and predicted by numerical models. The present study seeks to contribute to the current understanding of this subject, by performing state-of-the-art optical diagnostics to liquid sprays injected through two singe-hole nozzles of different conicity. The experiments were carried out in a nitrogen-filled constant-pressure-flow facility. Back pressures were set to produce the desired engine-like density conditions in the chamber, at room temperature. The experimental setup consists in a diffused back illumination setup with a fast pulsed LED light source and a high-speed camera. The diagnostics focused on detecting the liquid spray contour and evaluating the influence of nozzle geometry over the time-resolved and quasi-steady response of the spray dispersion, at similar injection conditions. Results show a clear influence of nozzle geometry on spray contour fluctuations, where the cylindrical nozzle seems to produce larger dispersion in both time-resolved fluctuations and quasi-steady values, when compared to the conical nozzle. This evidences that the turbulence and radial velocity profiles originated at the cylindrical nozzle geometry are able to affect not only the microscopic scales inside the nozzle, but also macroscopic scales such as the steady spray. Observations from this study indicate that the effects of the flow characteristics within the nozzle are carried on to the first millimeters of the spray, in which the

  19. Multi-component vapor-liquid equilibrium model for LES and application to ECN Spray A

    CERN Document Server

    Matheis, Jan

    2016-01-01

    We present and evaluate a detailed multi-species two-phase thermodynamic equilibrium model for large-eddy simulations (LES) of liquid-fuel injection and mixing at high pressure. The model can represent the coexistence of supercritical states and multi-component subcritical two-phase states. LES results for the transcritical Spray A of the Engine Combustion Network (ECN) are found to agree very well to available experimental data. We also address well-known numerical challenges of trans- and supercritical fluid mixing and compare a fully conservative formulation to a quasi conservative formulation of the governing equations. Our results prove physical and numerical consistency of both methods on fine grids and demonstrate the effects of energy conservation errors associated with the quasi conservative formulation on typical LES grids.

  20. Liquid Methane Testing With a Large-Scale Spray Bar Thermodynamic Vent System

    Science.gov (United States)

    Hastings, L. J.; Bolshinskiy, L. G.; Hedayat, A.; Flachbart, R. H.; Sisco, J. D.; Schnell. A. R.

    2014-01-01

    NASA's Marshall Space Flight Center conducted liquid methane testing in November 2006 using the multipurpose hydrogen test bed outfitted with a spray bar thermodynamic vent system (TVS). The basic objective was to identify any unusual or unique thermodynamic characteristics associated with densified methane that should be considered in the design of space-based TVSs. Thirteen days of testing were performed with total tank heat loads ranging from 720 to 420 W at a fill level of approximately 90%. It was noted that as the fluid passed through the Joule-Thompson expansion, thermodynamic conditions consistent with the pervasive presence of metastability were indicated. This Technical Publication describes conditions that correspond with metastability and its detrimental effects on TVS performance. The observed conditions were primarily functions of methane densification and helium pressurization; therefore, assurance must be provided that metastable conditions have been circumvented in future applications of thermodynamic venting to in-space methane storage.

  1. Liquid flow on a rotating disk prior to centrifugal atomization and spray deposition

    Science.gov (United States)

    Zhao, Y. Y.; Jacobs, M. H.; Dowson, A. L.

    1998-12-01

    Video observations of the flow patterns that develop on a rotating disk during centrifugal atomization and spray deposition, and subsequent metallographic studies conducted on solid skulls removed from the disk after processing, have indicated a circular discontinuity or hydraulic jump, which is manifested by a rapid increase in the thickness of the liquid metal and by a corresponding decrease in the radial velocity. A mathematical model has been developed that is capable of predicting both the occurrence and location of the jump, and the associated changes in the thickness profile and in the radial and tangential velocities of the liquid metal. Good correlations have been observed between model predictions and the flow patterns observed on the skull after atomization, and the effects of changes in material and operational parameters such as kinematic viscosity, volume flow rate, metallostatic head, and disk rotation speed have been quantified. Liquid metal flow is controlled primarily by the volume flow rate and by the metallostatic head prior to the hydraulic jump and by the centrifugal forces after the jump. The implications of these observations in terms of the atomization process are discussed.

  2. Nanostructured bioactive glass-ceramic coatings deposited by the liquid precursor plasma spraying process

    Science.gov (United States)

    Xiao, Yanfeng; Song, Lei; Liu, Xiaoguang; Huang, Yi; Huang, Tao; Wu, Yao; Chen, Jiyong; Wu, Fang

    2011-01-01

    Bioactive glass-ceramic coatings have great potential in dental and orthopedic medical implant applications, due to its excellent bioactivity, biocompatibility and osteoinductivity. However, most of the coating preparation techniques either produce only thin thickness coatings or require tedious preparation steps. In this study, a new attempt was made to deposit bioactive glass-ceramic coatings on titanium substrates by the liquid precursor plasma spraying (LPPS) process. Tetraethyl orthosilicate, triethyl phosphate, calcium nitrate and sodium nitrate solutions were mixed together to form a suspension after hydrolysis, and the liquid suspension was used as the feedstock for plasma spraying of P 2O 5-Na 2O-CaO-SiO 2 bioactive glass-ceramic coatings. The in vitro bioactivities of the as-deposited coatings were evaluated by soaking the samples in simulated body fluid (SBF) for 4 h, 1, 2, 4, 7, 14, and 21 days, respectively. The as-deposited coating and its microstructure evolution behavior under SBF soaking were systematically analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma (ICP), and Fourier transform infrared (FTIR) spectroscopy. The results showed that P 2O 5-Na 2O-CaO-SiO 2 bioactive glass-ceramic coatings with nanostructure had been successfully synthesized by the LPPS technique and the synthesized coatings showed quick formation of a nanostructured HCA layer after being soaked in SBF. Overall, our results indicate that the LPPS process is an effective and simple method to synthesize nanostructured bioactive glass-ceramic coatings with good in vitro bioactivity.

  3. Hydroxyapatite coatings deposited by liquid precursor plasma spraying: controlled dense and porous microstructures and osteoblastic cell responses

    Energy Technology Data Exchange (ETDEWEB)

    Huang Yi; Song Lei; Liu Xiaoguang; Xiao Yanfeng; Wu Yao; Chen Jiyong; Wu Fang; Gu Zhongwei, E-mail: fangwu0808@yahoo.co, E-mail: fwu@scu.edu.c [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064 (China)

    2010-12-15

    Hydroxyapatite coatings were deposited on Ti-6Al-4V substrates by a novel plasma spraying process, the liquid precursor plasma spraying (LPPS) process. X-ray diffraction results showed that the coatings obtained by the LPPS process were mainly composed of hydroxyapatite. The LPPS process also showed excellent control on the coating microstructure, and both nearly fully dense and highly porous hydroxyapatite coatings were obtained by simply adjusting the solid content of the hydroxyapatite liquid precursor. Scanning electron microscope observations indicated that the porous hydroxyapatite coatings had pore size in the range of 10-200 {mu}m and an average porosity of 48.26 {+-} 0.10%. The osteoblastic cell responses to the dense and porous hydroxyapatite coatings were evaluated with human osteoblastic cell MG-63, in respect of the cell morphology, proliferation and differentiation, with the hydroxyapatite coatings deposited by the atmospheric plasma spraying (APS) process as control. The cell experiment results indicated that the heat-treated LPPS coatings with a porous structure showed the best cell proliferation and differentiation among all the hydroxyapatite coatings. Our results suggest that the LPPS process is a promising plasma spraying technique for fabricating hydroxyapatite coatings with a controllable microstructure, which has great potential in bone repair and replacement applications.

  4. Thermal Spray Using a High-Frequency Pulse Detonation Combustor Operated in the Liquid-Purge Mode

    Science.gov (United States)

    Endo, T.; Obayashi, R.; Tajiri, T.; Kimura, K.; Morohashi, Y.; Johzaki, T.; Matsuoka, K.; Hanafusa, T.; Mizunari, S.

    2016-02-01

    Experiments on thermal spray by pulsed detonations at 150 Hz were conducted. Two types of pulse detonation combustors were used, one operated in the inert gas purge (GAP) mode and the other in the liquid-purge (LIP) mode. In both modes, all gases were supplied in the valveless mode. The GAP mode is free of moving components, although the explosive mixture is unavoidably diluted with the inert gas used for the purge of the hot burned gas. In the LIP mode, pure fuel-oxygen combustion can be realized, although a liquid-droplet injector must be actuated cyclically. The objective of this work was to demonstrate a higher spraying temperature in the LIP mode. First, the temperature of CoNiCrAlY particles heated by pulsed detonations was measured. As a result, the spraying temperature in the LIP mode was higher than that in the GAP mode by about 1000 K. Second, the temperature of yttria-stabilized zirconia (YSZ) particles, whose melting point was almost 2800 °C, heated by pulsed detonations in the LIP mode was measured. As a result, the YSZ particles were heated up to about 2500 °C. Finally, a thermal spray experiment using YSZ particles was conducted, and a coating with low porosity was successfully deposited.

  5. The effect of acidification of liquid whey protein concentrate on the flavor of spray-dried powder.

    Science.gov (United States)

    Park, Curtis W; Bastian, Eric; Farkas, Brian; Drake, MaryAnne

    2014-07-01

    Off-flavors in whey protein negatively influence consumer acceptance of whey protein ingredient applications. Clear acidic beverages are a common application of whey protein, and recent studies have demonstrated that beverage processing steps, including acidification, enhance off-flavor production from whey protein. The objective of this study was to determine the effect of preacidification of liquid ultrafiltered whey protein concentrate (WPC) before spray drying on flavor of dried WPC. Two experiments were performed to achieve the objective. In both experiments, Cheddar cheese whey was manufactured, fat-separated, pasteurized, bleached (250 mg/kg of hydrogen peroxide), and ultrafiltered (UF) to obtain liquid WPC that was 13% solids (wt/wt) and 80% protein on a solids basis. In experiment 1, the liquid retentate was then acidified using a blend of phosphoric and citric acids to the following pH values: no acidification (control; pH 6.5), pH 5.5, or pH 3.5. The UF permeate was used to normalize the protein concentration of each treatment. The retentates were then spray dried. In experiment 2, 150 μg/kg of deuterated hexanal (D₁₂-hexanal) was added to each treatment, followed by acidification and spray drying. Both experiments were replicated 3 times. Flavor properties of the spray-dried WPC were evaluated by sensory and instrumental analyses in experiment 1 and by instrumental analysis in experiment 2. Preacidification to pH 3.5 resulted in decreased cardboard flavor and aroma intensities and an increase in soapy flavor, with decreased concentrations of hexanal, heptanal, nonanal, decanal, dimethyl disulfide, and dimethyl trisulfide compared with spray drying at pH 6.5 or 5.5. Adjustment to pH 5.5 before spray drying increased cabbage flavor and increased concentrations of nonanal at evaluation pH values of 3.5 and 5.5 and dimethyl trisulfide at all evaluation pH values. In general, the flavor effects of preacidification were consistent regardless of the pH to

  6. Iron Oxide Doped Alumina-Zirconia Nanoparticle Synthesis by Liquid Flame Spray from Metal Organic Precursors

    Directory of Open Access Journals (Sweden)

    Juha-Pekka Nikkanen

    2008-01-01

    Full Text Available The liquid flame spray (LFS method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical composition were determined by TEM, XRD, XPS, and N2-adsorption measurements. The collected particulate material consists of micron-sized aggregates with nanosized primary particles. In both doped and undoped samples, tetragonal phase of zirconia was detected in room temperature while alumina was found to be noncrystalline. In the doped powder, Fe was oxidized to Fe2O3. The primary particle size of collected sample was approximately from 6 nm to 40 nm. Doping was observed to increase the specific surface area of the powder from 39 m2/g to 47 m2/g.

  7. Spray Bar Zero-Gravity Vent System for On-Orbit Liquid Hydrogen Storage

    Science.gov (United States)

    Hastings, L. J.; Flachbart, R. H.; Martin, J. J.; Hedayat, A.; Fazah, M.; Lak, T.; Nguyen, H.; Bailey, J. W.

    2003-01-01

    During zero-gravity orbital cryogenic propulsion operations, a thermodynamic vent system (TVS) concept is expected to maintain tank pressure control without propellant resettling. In this case, a longitudinal spray bar mixer system, coupled with a Joule-Thompson (J-T) valve and heat exchanger, was evaluated in a series of TVS tests using the 18 cu m multipurpose hydrogen test bed. Tests performed at fill levels of 90, 50, and 25 percent, coupled with heat tank leaks of about 20 and 50 W, successfully demonstrated tank pressure control within a 7-kPa band. Based on limited testing, the presence of helium constrained the energy exchange between the gaseous and liquid hydrogen (LH2) during the mixing cycles. A transient analytical model, formulated to characterize TVS performance, was used to correlate the test data. During self-pressurization cycles following tank lockup, the model predicted faster pressure rise rates than were measured; however, once the system entered the cyclic self-pressurization/mixing/venting operational mode, the modeled and measured data were quite similar. During a special test at the 25-percent fill level, the J-T valve was allowed to remain open and successfully reduced the bulk LH2 saturation pressure from 133 to 70 kPa in 188 min.

  8. Reaction mechanism of lanthanum nitrate-doped Mo-La material during solid-liquid spray doping processing

    Institute of Scientific and Technical Information of China (English)

    Peng-Fa Feng; Qin-Li Yang; Xiao-Ming Dang; Sha Xi; Ya-Qi Wang

    2015-01-01

    At three critical temperatures which were obtained by thermo-gravimetry-differential thermal analysis-differential scanning calorimetry (TG/DTG/DSC)curves of lanthanum nitrate crystal,the air thermal decomposition experiments and solid-liquid spray doping simulation procedures of lanthanum nitrate crystal were carried out,and their products were analyzed by X-ray diffraction (XRD).Meanwhile,the spray doping processing of MoO2-50 wt% La(NO3)3 composite powder was undergone with lanthanum nitrate solution as the dopant,and doped MoO2 powder was analyzed by XRD.The results demonstrate that during the traditional solid-liquid spray doping processing,lanthanum nitrate,in the form of either crystal or aqueous solution,would be converted into La(NO3)3·4H2O by the dehydration reaction,rather than be decomposed to La2O3 and NO or NO2.Therefore,it is inferred that the oxynitride gas produced from the process is attributed to the decomposition of residual HNO3 in lanthanum nitrate crystal.The source of HNO3 is supported by the chemical composition of lanthanum nitrate crystal.

  9. Physicochemical and Antioxidant Properties of Spray Drying Powders from Stropharia rugoso-annulata and Agaricus brunnescens Blanching Liquid

    Directory of Open Access Journals (Sweden)

    Yibin Li

    2015-08-01

    Full Text Available This study investigated the impacts of carrier agents on the physicochemical properties and antioxidant retention rate of spray drying powders from blanching liquids of Stropharia rugoso-annulata (BLS and Agaricus brunnescens (BLA. Physicochemical, nutritional and antioxidant properties of the powder were examined in order to better determine potential applications of powders. Carrier agents could improve the qualities of the spray drying BLS powders and BLA powders and &beta-Cyclodextrin (&beta-CD was more suitable as carrier agent than Maltodextrin (MD. The powder had higher flour yield and antioxidant retention rate while &beta-CD addition rate was 44.44 g/100 g (w/w.Proximate composition and total phenolics were performed. The powder was ranging from 5 and 30 μm in particle size with spherical particle morphology. BLA powders had higher antioxidant activity (hydroxyl radical scavenging capacity and lipid peroxidation inhibition ability than BLS powder.

  10. A Review on Empirical Correlations for Jet/Spray Trajectory of Liquid Jet in Uniform Cross Flow

    Directory of Open Access Journals (Sweden)

    Soo-Young No

    2015-12-01

    Full Text Available The empirical correlations for the prediction of jet/spray penetration of liquid jet in subsonic uniform crossflow are reviewed in this study. Considerable number of empirical correlations had been proposed by many investigators. It has generally known that the jet/spray trajectory of a liquid jet in a cross-flow is a function of the liquid to air momentum flux ratio and the normalized distance in the airstream direction from the injector. However, several researchers incorporated the Weber number, liquid-to-water or air viscosity ratio, pressure ratio or Reynolds number, temperature ratio in the empirical correlations. Two different classification methods of correlations, i.e. classification based on mathematic functional form and classification based on flow regime, are introduced in this study. The one classification of existing correlations based on functional form includes correlations in a power-law, logarithmic, and exponential forms, respectively. The other classification of previous correlations based on flow regime includes one, two and three regime, correlations. Correlations in a power-law functional form can be further divided into three groups such as momentum flux ratio, Weber number and other parameters forms. Correlations in logarithmic functional form can be also grouped as momentum flux ratio and Weber number forms. Most of the evaluation studies reported the significant discrepancies of predicted values by the existing correlations. The possible reasons for discrepancies will be summarized as measurement technique, assumptions made in defining terms in the liquid to air momentum flux ratio, difficulties in defining the boundaries of the liquid jets, turbulence level in the core and boundary layer of incoming jet and gas flows, nozzle/injector geometry and its position in the crossflow. However, it can be found from the several evaluation studies that the power-law functional form with momentum flux ratio and two regimes

  11. AFM fluid delivery/liquid extraction surface sampling/electrostatic spray cantilever probe

    Science.gov (United States)

    Van Berkel, Gary J.

    2015-06-23

    An electrospray system comprises a liquid extraction surface sampling probe. The probe comprises a probe body having a liquid inlet and a liquid outlet, and having a liquid extraction tip. A solvent delivery conduit is provided for receiving solvent liquid from the liquid inlet and delivering the solvent liquid to the liquid extraction tip. An open liquid extraction channel extends across an exterior surface of the probe body from the liquid extraction tip to the liquid outlet. An electrospray emitter tip is in liquid communication with the liquid outlet of the liquid extraction surface sampling probe. A system for analyzing samples, a liquid junction surface sampling system, and a method of analyzing samples are also disclosed.

  12. Correlations between the two-phase gas/liquid spray atomization and the Stokes/aerodynamic Weber numbers

    Science.gov (United States)

    Rahman, Mohammad A.; Heidrick, Ted; Fleck, Brian A.

    2009-02-01

    The The effects of air-to-liquid ratio (β) and void fraction (α) on Sauter mean diameter (SMD or D32), arithmetic mean diameter (D10), surface mean diameter (D20), volume mean diameter (VMD or D20), and radial velocity profiles were experimentally investigated for a two-phase gas/liquid (TPGL) nozzle with a hybrid design of classical twin-fluid and effervescent nozzles. Radial spray profiles were measured using a Phase-Doppler-Particle-Anemometer (PDPA) system on 15Dn, 30Dn, 60Dn, 120Dn;(Dn represents nozzle diameter = 3.10,mm) axial distances. In addition, the effects of spray break-up patterns were analyzed with changing axial distances. The average void fraction in the feeding conduit (FC) was measured by a pneumatic controlled quick-closing-valve (QCV). The experiments were performed using mixtures of air with water at water flow rates of 1.50 to 7.50 kg/min and air-to-liquid mass ratios (β) of 0.30 to 10;%. The length and diameter of the FC was 36.8,cm and 6.35,mm, respectively. Result indicates that as the St number reaches the value of one, no more break-up continues, thus the droplets start to coalesce each other forming bigger droplets (higher D10 values) with increasing radial distances. Knowledge from this study will provide better understanding that ensures an increase in plant efficiency and product yield in oil sands bitumen upgrading.

  13. Exposure data for personal care products: hairspray, spray perfume, liquid foundation, shampoo, body wash, and solid antiperspirant.

    Science.gov (United States)

    Loretz, Linda; Api, Anne Marie; Barraj, Leila; Burdick, Joel; Davis, De Ann; Dressler, William; Gilberti, Enrico; Jarrett, Gwendolyn; Mann, Steve; Laurie Pan, Y H; Re, Thomas; Renskers, Kevin; Scrafford, Carolyn; Vater, Sally

    2006-12-01

    Reliable exposure information for cosmetic and other personal care products and ingredients is needed in order to conduct safety assessments. Essential information includes both the amount of product applied, and the frequency of use. To obtain current data, studies to assess consumer use practices were undertaken. Six widely used personal care product types were included in the studies. Five of the products were cosmetics (spray perfume, hairspray, liquid foundation, shampoo, body wash) and one product was a cosmetic/over-the-counter drug product (solid antiperspirant). Three hundred and sixty women, ages 19-65 years, who regularly use the products of interest, were recruited at 10 different geographical locations within the US. The number of recruits was chosen to ensure a minimum of three hundred completed responses per product type. Subjects were provided with a new container of the brand of product they normally use and kept diaries and recorded detailed daily usage information over a two week period. Products were weighed at the start and completion of the study in order to determine the total amount of product used. Statistical analyses of the data were conducted to derive summary distributions of use patterns. The geometric mean and median usage per application, respectively, for the six product types were: spray perfume, 0.33 g and 0.23 g; hairspray, 2.58 g and 1.83 g (aerosol); 3.64 g and 2.66 g (pump); liquid foundation, 0.54 g and 0.36 g; shampoo, 11.76 g and 9.56 g; body wash, 11.3g and 9.5 g; and solid antiperspirant, 0.61 g and 0.45 g. The mean and median usage per day for the six product types were: spray perfume, 0.53 g and 0.34 g; hairspray, 3.57 g and 2.71 g (aerosol); 5.18 g and 3.74 g (pump); liquid foundation, 0.67 g and 0.45 g; shampoo, 12.80 g and 10.75 g; body wash, 14.5 g and 12.9 g; and solid antiperspirant, 0.79 g and 0.59 g. The mean number of applications per day for spray perfume, hairspray, liquid foundation, shampoo, body wash, and

  14. Using a test solution of NaCl in water for studying the finely dispersed spraying of liquids

    Science.gov (United States)

    Ishmatov, A. N.; Vorozhtsov, B. I.; Arkhipov, V. A.

    2013-12-01

    Both theoretically and experimentally, the suitability of a technique for studying the finely dispersed spraying of liquids based on an analysis of salt residue particles formed as a result of evaporation of test solutions of NaCl in water was evaluated. Data gained in studying the dispersion of droplets in the droplet clouds produced by pulsed and ultrasonic atomizers are reported. During pulsed atomization, salt residue particles of various morphologies were found to form, this finding pointing to realization of unsteady conditions for particle evolution.

  15. Identification of multiply charged proteins and amino acid clusters by liquid nitrogen assisted spray ionization mass spectrometry.

    Science.gov (United States)

    Kumar Kailasa, Suresh; Hasan, Nazim; Wu, Hui-Fen

    2012-08-15

    The development of liquid nitrogen assisted spray ionization mass spectrometry (LNASI MS) for the analysis of multiply charged proteins (insulin, ubiquitin, cytochrome c, α-lactalbumin, myoglobin and BSA), peptides (glutathione, HW6, angiotensin-II and valinomycin) and amino acid (arginine) clusters is described. The charged droplets are formed by liquid nitrogen assisted sample spray through a stainless steel nebulizer and transported into mass analyzer for the identification of multiply charged protein ions. The effects of acids and modifier volumes for the efficient ionization of the above analytes in LNASI MS were carefully investigated. Multiply charged proteins and amino acid clusters were effectively identified by LNASI MS. The present approach can effectively detect the multiply charged states of cytochrome c at 400 nM. A comparison between LNASI and ESI, CSI, SSI and V-EASI methods on instrumental conditions, applied temperature and observed charge states for the multiply charged proteins, shows that the LNASI method produces the good quality spectra of amino acid clusters at ambient conditions without applied any electric field and heat. To date, we believe that the LNASI method is the most simple, low cost and provided an alternative paradigm for production of multiply charged ions by LNASI MS, just as ESI-like ions yet no need for applying any electrical field and it could be operated at low temperature for generation of highly charged protein/peptide ions.

  16. Comparison between a spray column and a sieve tray column operating as liquid-liquid heat exchangers

    Science.gov (United States)

    Keller, A. S.; Jacobs, H. R.; Boehm, R. F.

    The reported investigation was conducted in connection with research intended to improve the efficiency of direct contact devices for geothermal and solar applications. The investigation had the objective to evaluate the effect of adding sieve trays to the laboratory column used in studies concerned with the development of models for spray column heat transfer. Hot water is pumped from a supply vessel into the top of the heat exchanger column where, as the continuous phase, it flows down through the column. The dispersed phase is kerosene. Using an identical pump to that used for the water, the kerosene flows into a dispersion plate in the bottom of the column. The droplets rise through the column and coalesce at the top. It was found that the heat transfer performance of the perforated plate column was significantly improved over that in a spray column for similar operating conditions.

  17. Comparison of the Viscous Liquids Spraying by the OIG and the Oil Configurations of an Effervescent Atomizer at Low Inlet Pressures

    Directory of Open Access Journals (Sweden)

    Mlkvik Marek

    2016-07-01

    Full Text Available In this work we studied the influence of the fluid injection configuration (OIG: outside-in-gas, OIL: outside-in-liquid on the internal flows and external sprays parameters. We sprayed the viscous aqueous maltodextrin solutions (μ = 60 mPa·s at a constant inlet pressure of the gas and the gas to the liquid mass flow ratio (GLR within the range 2.5 to 20%. We found that the fluids injection has a crucial influence on the internal flows. The internal flows patterns for the OIG atomizer were the slug flows, the internal flow of the OIL device was annular which led to the significant improvement of the spray quality: Smaller droplets, faster atomization, fewer pulsations.

  18. A Comparison of Shadowgraphy and X-ray Computed Tomography in Liquid Spray Analysis

    Science.gov (United States)

    2014-11-14

    atomizers, the orifice diameter, d0, is Table 1: Dimensionless and dimensional parameters for each nozzle and experiment generally around 150 µm...volumetric flow into a graduated cylinder after one minute. Using the calculated volumetric flow rate along with the known orifice size of each...The X-ray source was located 1422 mm away from the rotation axis of the spray system, and the detector was 398 mm on the opposite side . Operating at

  19. Characteristics of Subcooled Liquid Methane During Passage Through a Spray-Bar Joule-Thompson Thermodynamic Vent System

    Science.gov (United States)

    Hastings, L. J.; Bolshinskiy, L. G.; Hedayat, A.; Schnell, A.

    2011-01-01

    NASA s Marshall Space Flight Center (MSFC) conducted liquid methane (LCH4) testing in November 2006 using the multipurpose hydrogen test bed (MHTB) outfitted with a spray-bar thermodynamic vent system (TVS). The basic objective was to identify any unusual or unique thermodynamic characteristics associated with subcooled LCH4 that should be considered in the design of space-based TVSs. Thirteen days of testing were performed with total tank heat loads ranging from 720 W to 420 W at a fill level of approximately 90%. During an updated evaluation of the data, it was noted that as the fluid passed through the Joule Thompson expansion, thermodynamic conditions consistent with the pervasive presence of metastability were indicated. This paper describes the observed thermodynamic conditions that correspond with metastability and effects on TVS performance.

  20. Atomized spraying of liquid metal droplets on desired substrate surfaces as a generalized way for ubiquitous printed electronics

    Science.gov (United States)

    Zhang, Qin; Gao, Yunxia; Liu, Jing

    2014-09-01

    A direct electronics printing technique through atomized spraying for patterning room-temperature liquid metal droplets on desired substrate surfaces is proposed and experimentally demonstrated for the first time. This method is highly flexible and capable of fabricating electronic components on various target objects, with either flat or rough surfaces, made of different materials, or having different orientations from 2D to 3D geometrical configurations. With a pre-designed mask, the liquid metal ink can be directly deposited on the substrate to form various specific patterns which lead to the rapid prototyping of electronic devices. Further, extended printing strategies were also suggested to illustrate the adaptability of the method. For example, it can be used for making transparent conductive film with an optical transmittance of 47 % and a sheet resistance of 5.167Ω/□ due to natural porous structure. Different from the former direct writing technology where large surface tension and poor adhesion between the liquid metal and the substrate often impede the flexible printing process, the liquid metal here no longer needs to be pre-oxidized to guarantee its applicability on target substrates. One critical mechanism was that the atomized liquid metal microdroplets can be quickly oxidized in the air due to its large specific surface area, resulting in a significant increase of the adhesion capacity and thus firm deposition of the ink to the substrate. This study paved a generalized way for pervasively and directly printing electronics on various substrates which are expected to be significant in a wide spectrum of electrical engineering areas.

  1. Characterization of sprays

    Science.gov (United States)

    Chigier, N.; Mao, C.-P.

    1984-01-01

    It is pointed out that most practical power generation and propulsion systems involve the burning of different types of fuel sprays, taking into account aircraft propulsion, industrial furnaces, boilers, gas turbines, and diesel engines. There has been a lack of data which can serve as a basis for spray model development and validation. A major aim of the present investigation is to fill this gap. Experimental apparatus and techniques for studying the characteristics of fuel sprays are discussed, taking into account two-dimensional still photography, cinematography, holography, a laser diffraction particle sizer, and a laser anemometer. The considered instruments were used in a number of experiments, taking into account three different types of fuel spray. Attention is given to liquid fuel sprays, high pressure pulsed diesel sprays, and coal-water slurry sprays.

  2. Measurements of the liquid phase temperature in fuel sprays via exciplex fluorescence method. 1st Report. Development of the measuring technique and application to fuel sprays injected into atmospheric pressure and high temperature environments; Exciplex keikoho ni yoru nenryo funmu no ekiso ondo bunpu sokutei. 1. Sokutei shuho no kaihatsu to joatsu koon fun`ikichu ni okeru funmu eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizaki, T.; Nishida, K.; Hiroyasu, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering; Funahashi, T.

    1998-07-25

    A measuring method based on the exciplex fluorescence technique has been developed for planar measurements of the liquid phase temperature distribution in fuel sprays. The liquid fuel (n-hexadecane or squalane) was doped with pyrene (C16H10). The fluorescence intensity ratios of the pyrene monomer and excimer emissions has temperature dependence, and were used to determine the liquid phase temperatures in the fuel sprays. The spray was excited by laser radiation at 266 nm, and the resulting fluorescence was imaged by an intensified CCD camera. The cross-sectional distribution of the liquid phase temperature was estimated from the fluorescence image by the temperature dependence of the intensity ratio. The results demonstrate that this laser-based thermometry technique is available for 2-D measurements of the liquid phase temperature in fuel sprays. 13 refs., 15 figs., 2 tabs.

  3. Viscous Potential Flow Analysis of Electroaerodynamic Instability of a Liquid Sheet Sprayed with an Air Stream

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar Awasthi

    2013-01-01

    Full Text Available The instability of a thin sheet of viscous and dielectric liquid moving in the same direction as an air stream in the presence of a uniform horizontal electric field has been carried out using viscous potential flow theory. It is observed that aerodynamic-enhanced instability occurs if the Weber number is much less than a critical value related to the ratio of the air and liquid stream velocities, viscosity ratio of two fluids, the electric field, and the dielectric constant values. Liquid viscosity has stabilizing effect in the stability analysis, while air viscosity has destabilizing effect.

  4. Spray characteristic of gas-liquid double swirl coaxial injector%气液同轴双离心式喷嘴喷雾特性

    Institute of Scientific and Technical Information of China (English)

    康忠涛; 李清廉; 张新桥; 成鹏

    2014-01-01

    采用流体体积方法分析涡流器离心式喷嘴内部流动过程,采用单反相机和相位多普勒测速仪测量离心式喷嘴、气液同轴双离心式喷嘴的喷雾特性。发现涡流器离心式喷嘴内部流动的总压损失主要发生在涡流器槽道入口、收敛段和等直段。等直段使液膜厚度减小,喷雾锥角减小。离心式喷嘴喷雾粒径分布范围沿径向逐渐增加,轴向速度分布范围沿径向先减小后逐渐增加。气液同轴双离心式喷嘴喷雾特性受气液比影响很大,气液比小时旋流空气使喷雾锥角增加,粒径分布范围减小;气液比大时,气体膨胀压缩喷雾,使大液滴能够到达喷雾中心,喷雾外侧为二次雾化成的细小液滴。%The volume of fluid method was used to analyze the flow process in pressure swirl injector.SLR camera and phase doppler anemometry were used to measure the spray characteristics of swirl injector and gas-liquid double swirl coaxial injector.Results show that the total pressure loss occurs mainly in inlet section,convergent section,and columned section of swirler trough.The longer the columned section is,the thicker the liquid film and the smaller the spray cone angle is.The range of spay particle distribution increases gradually along the radial direction while the axial velocity distribution decreases firstly and then increases along radial direction.Spray characteristic of gas-liquid double swirl coaxial injector is greatly influenced by gas-liquid ratio (GLR).While GLR is small enough,swirling air increases the spray cone angle and decreases the range of particle distribution;while GLR is large enough,the expansion of air compresses the spray,pushing large droplets to the center of the spray.And at the edge of spray locates small droplets from second atomization.

  5. Determination of organophosphorus acids by thermo-spray liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Wils, E.R.J.; Hulst, A.G.

    1988-01-01

    The determination of thirteen organophosphorus acids, hydrolysis products of nerve agents and pesticides, by a combination of ion-pair liquid chromatography on a reversed-phase C18 column and thermospray mass spectrometry was investigated. Ammonium acetate and three tetraalkylammonium salts with dif

  6. Design Optimization of Liquid Fueled High Velocity Oxy- Fuel Thermal Spraying Technique for Durable Coating for Fossil Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Choudhuri, Ahsan [Univ. of Texas, El Paso, TX (United States); Love, Norman [Univ. of Texas, El Paso, TX (United States)

    2016-11-04

    High-velocity oxy–fuel (HVOF) thermal spraying was developed in 1930 and has been commercially available for twenty-five years. HVOF thermal spraying has several benefits over the more conventional plasma spray technique including a faster deposition rate which leads to quicker turn-around, with more durable coatings and higher bond strength, hardness and wear resistance due to a homogeneous distribution of the sprayed particles. HVOF thermal spraying is frequently used in engineering to deposit cermets, metallic alloys, composites and polymers, to enhance product life and performance. HVOF thermal spraying system is a highly promising technique for applying durable coatings on structural materials for corrosive and high temperature environments in advanced ultra-supercritical coal- fired (AUSC) boilers, steam turbines and gas turbines. HVOF thermal spraying is the preferred method for producing coatings with low porosity and high adhesion. HVOF thermal spray process has been shown to be one of the most efficient techniques to deposit high performance coatings at moderate cost. Variables affecting the deposit formation and coating properties include hardware characteristics such as nozzle geometry and spraying distance and process parameters such as equivalence ratio, gas flow density, and powder feedstock. In the spray process, the powder particles experience very high speeds combined with fast heating to the powder material melting point or above. This high temperature causes evaporation of the powder, dissolution, and phase transformations. Due to the complex nature of the HVOF technique, the control and optimization of the process is difficult. In general, good coating quality with suitable properties and required performance for specific applications is the goal in producing thermal spray coatings. In order to reach this goal, a deeper understanding of the spray process as a whole is needed. Although many researchers studied commercial HVOF thermal spray

  7. THERMAL AND THERMODYNAMIC CHARACTERIZATION OF A DYE POWDER FROM LIQUID TURMERIC EXTRACTS BY SPRAY DRYING

    Directory of Open Access Journals (Sweden)

    Aura Yazmin Coronel Delgado

    2016-01-01

    Full Text Available This study aimed to evaluate the thermodynamic properties of sorption isotherms and glass transition temperature (Tg and the thermal properties of a dye powder obtained from turmeric extracts using spray drying. The sorption isotherms were evaluated at 15, 25 and 35 ºC using the dynamic gravimetric method, wherein the isotherm data of the experiment were fit to GAB and BET models. Likewise, the Tg was measured using differential scanning calorimetry (DSC. Thermogravimetric analysis (TGA was used to determine the mass loss, and the thermal properties (heat capacity, diffusivity and thermal conductivity were determined using transient flow method. The results demonstrated that the GAB model best fit the adsorption data. The DSC analysis presented a glass transition temperature of 65.35 ºC and a loss of volatiles at 178.07 ºC. The TGA analysis indicated a considerable mass loss starting at 193 ºC, resulting in degradation of the product. The thermal properties demonstrated a heat capacity of 2.45 J/g ºC, a thermal conductivity of 0.164 ±0.001 W/mK and a thermal diffusivity of 8.7x10-8 ± 0.000 m2/s

  8. 射流表面波理论的研究进展%Theoretical Investigation Evolvement of Surface Waves in Liquid Jet Sprays

    Institute of Scientific and Technical Information of China (English)

    曹建明

    2014-01-01

    在过去的20年中,喷雾科学与技术有了长足的发展,应用领域不断扩大。目前,喷雾学已经成为国际性的研究领域。其发展主要表现在数学模型的进展、数值计算分析的不断完善和光学测试技术的改进与开发,重要性日益显著。本文论述了利用线性稳定性理论和非线性稳定性理论对典型的圆射流、平面液膜射流和环状液膜射流碎裂过程的研究进展。%In the past twenty years, spray science and technology has been made great progress and its application field has been enlarged gradually. Nowadays, spray has already become an international research field. The development mainly involves the evolvement of mathematical model, the promotion of numerical calculation and analysis, and the improvement and development of optical techniques for the droplet size measurement. The importance of sprays is increasing gradually. An investigation evolvement is presented for the typical fluid model, such as liquid jet, planar liquid sheet and annular liquid sheet, breakup processes by using linear and nonlinear stability theories.

  9. Assessing the optimal liquid volume to be sprayed on isolated olive trees according to their canopy volumes.

    Science.gov (United States)

    Miranda-Fuentes, A; Llorens, J; Rodríguez-Lizana, A; Cuenca, A; Gil, E; Blanco-Roldán, G L; Gil-Ribes, J A

    2016-10-15

    The application of pesticides to traditional and intensive olive orchards in Southern Spain has led to environmental problems. More specifically, the lack of an accurate, useful criterion to regulate the spray volume in relation to canopy characteristics has led to spray drift and runoff, which are threats to local ecosystems. The aim of this study was to determine the optimal relationship between canopy volume and the spray application volume, called specific spray volume, CV, through laboratory and field trials. In the laboratory trial, 6 specific spray volumes (0.05, 0.08, 0.10, 0.12, 0.15, and 0.20Lm(-3)) were tested in a specially designed structure containing small, live olive trees in order to simulate an intensive plantation system. The model aimed to evaluate the coverage of pesticide application on water sensitive paper (WSP) collectors. In the field trial, the three laboratory specific spray volumes that gave the best coverage values were tested on live, intensively managed trees, whose crown volume was manually measured. Food dye E-102 was used to determine the spray deposition on artificial targets (10×10cm absorbent paper pieces), and WSP was used to evaluate spray coverage. The spray penetration and deposit homogeneity inside the canopy were also evaluated. Weather conditions during the field trial were monitored with a weather station. The results of the laboratory trial showed that the three best specific spray volumes were 0.08, 0.10, and 0.12Lm(-3), resulting in mean coverage values of approximately 30%. The ANOVA of the field trial results showed that the 0.12Lm(-3) was the optimal specific spray volume for isolated olive trees. This specific spray volume gave the highest mean deposits, the best efficiency (as measured by the greatest normalized deposit), the most favourable penetration and homogeneity, and the highest coverage values.

  10. Quantitative determination of acetylcholine in microdialysis samples using liquid chromatography/atmospheric pressure spray ionization mass spectrometry.

    Science.gov (United States)

    Keski-Rahkonen, Pekka; Lehtonen, Marko; Ihalainen, Jouni; Sarajärvi, Timo; Auriola, Seppo

    2007-01-01

    A fast, simple and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the determination of acetylcholine in rat brain microdialysis samples. The chromatographic separation was achieved in 3 min on a reversed-phase column with isocratic conditions using a mobile phase containing 2% (v/v) of acetonitrile and 0.05% (v/v) of trifluoroacetic acid (TFA). A stable isotope-labeled internal standard was included in the analysis and detection was carried out with a linear ion trap mass spectrometer using selected reaction monitoring (SRM). Analyte ionization was performed with an atmospheric pressure chemical ionization (APCI) source without applying discharge current (atmospheric pressure spray ionization). This special ionization technique offered significant advantages over electrospray ionization for the analysis of acetylcholine with reversed-phase ion-pairing chromatography. The lower limit of quantification was 0.15 nM (1.5 fmol on-column) and linearity was maintained over the range of 0.15-73 nM, providing a concentration range that is significantly wider than that of the existing LC/MS methods. Good accuracy and precision were obtained for concentrations within the standard curve range. The method was validated and has been used extensively for the determination of acetylcholine in rat brain microdialysis samples.

  11. Hydrophilic interaction liquid chromatography-electrospray ionization-tandem mass spectrometry of a complex mixture of native and oxidized phospholipids.

    Science.gov (United States)

    Losito, I; Facchini, L; Diomede, S; Conte, E; Megli, F M; Cataldi, T R I; Palmisano, F

    2015-11-27

    A mixture of native and oxidized phospholipids (PLs), generated by the soybean lipoxygenase type V-catalyzed partial oxidation of a lipid extract obtained from human platelets, was analyzed by Hydrophilic Interaction Liquid Chromatography-ElectroSpray Ionization-Tandem Mass Spectrometry (HILIC-ESI-MS/MS). The complexity of the resulting mixture was remarkable, considering that the starting lipid extract, containing (as demonstrated in a previous study) about 130 native PLs, was enriched with enzymatically generated hydroperoxylated derivatives and chemically generated hydroxylated forms of PLs bearing polyunsaturated side chains. Nonetheless, the described analytical approach proved to be very powerful; indeed, focusing on phosphatidylcolines (PCs), the most abundant PL class in human platelets, about fifty different native/oxidized species could be identified in a single HILIC-ESI-MS/MS run. Low-energy collision induced dissociation tandem MS (CID-MS/MS) experiments on chromatographically separated species showed single neutral losses of H2O2 and H2O to be typical fragmentation pathways of hydroperoxylated PCs, whereas a single H2O loss was observed for hydroxylated ones. Moreover, diagnostic losses of n-hexanal or n-pentanol were exploited to recognize PCs hydroperoxylated on the last but five carbon atom of a ɷ-6 polyunsaturated side chain. Despite the low resolution of the 3D ion trap mass analyzer used, the described HILIC-ESI-MS/MS approach appears very promising for the identification of oxidized lipids in oxidatively stressed complex biological systems.

  12. [The spectra of a laser-produced plasma source with CO2, O2 and CF4 liquid aerosol spray target].

    Science.gov (United States)

    Ni, Qi-Liang; Chen, Bo

    2008-11-01

    A laser-produced plasma (LPP) source with liquid aerosol spray target and nanosecond laser was developed, based on both soft X-ray radiation metrology and extreme ultraviolet projection lithography (EUVL). The LPP source is composed of a stainless steel solenoid valve whose temperature can be continuously controlled, a Nd : YAG laser with pulse width, working wavelength and pulse energy being 7 ns, 1.064 microm and 1J respectively, and a pulse generator which can synchronously control the valve and the laser. A standard General Valve Corporation series 99 stainless steel solenoid valve with copper gasket seals and a Kel-F poppet are used in order to minimize leakage and poppet deformation during high-pressure cryogenic operation. A close fitting copper cooling jacket surrounds the valve body. The jacket clamps a copper coolant carrying tube 3 mm in diameter, which is fed by an automatically pressurized liquid nitrogen-filled dewar. The valve temperature can be controlled between 77 and 473 K. For sufficiently high backing pressure and low temperature, the valve reservoir gas can undergo a gas-to-liquid phase transition. Upon valve pulsing, the liquid is ejected into a vacuum and breaks up into droplets, which is called liquid aerosol spray target. For the above-mentioned LPP source, firstly, by the use of Cowan program on the basis of non-relativistic quantum mechanics, the authors computed the radiative transition wavelengths and probabilities in soft X-ray region for O4+, O5+, O6+, O7+, F5+, F6+ and F7+ ions which were correspondingly produced from the interaction of the 10(11)-10(12) W x cm(-2) power laser with liquid O2, CO2 and CF4 aerosol spray targets. Secondly, the authors measured the spectra of liquid O2, CO2 and CF4 aerosol spray target LPP sources in the 6-20 nm band for the 8 x 10(11) W x cm(-2) laser irradiance. The measured results were compared with the Cowan calculated results ones, and the radiative transition wavelength and probability for the

  13. Experimental study on the effect of surface conditions on evaporation of sprayed liquid droplet

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed R, Negeed [Reactors Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); El-Sayed R, Negeed; Ishihara, N.; Tagashira, K.; Hidaka, S.; Kohno, M.; Takata, Y. [Department of Mechanical Engineering Science, Faculty of Engineering, Kyushu University, Fukuoka (Japan)

    2010-12-15

    The present study investigates experimentally the effects of thermal properties of the hot surface and droplet characteristics on the droplet evaporation. Cylindrical blocks made of Stainless Steel, Aluminum and Brass with different degrees of surface roughness were used. The droplet diameter and velocity were controlled independently. The behavior of droplet during the collision with hot surface was observed with a high-speed camera. The results presented the effect of the thermal properties of the hot surface, droplet Weber number, droplet velocity, droplet size, hot surface conditions; surface superheat and degree of surface roughness on the solid-liquid contact time and the maximum spread of droplet over the surface. Empirical correlations have been deduced describing the relationship between the hydrodynamic characteristics of an individual droplet impinging on a heated surface and concealing the affecting parameters in such process. Also, the comparison between the current results and the results due to others investigators shows good agreement in which the difference between them ranged from 5% to 25%. (authors)

  14. Determination of sodium cromoglycate in human plasma by liquid chromatography-mass spectrometry in the turbo ion spray mode.

    Science.gov (United States)

    Ozou, M L; Girault, J; Malgouyat, J M; Pasquier, O

    2001-12-25

    A highly sensitivity liquid chromatography-tandem mass spectrometry method has been developed for the quantitation of sodium cromoglycate (SCG) in human plasma. The method was validated over a linear range of 0.100-50.0 ng/ml, using 13C4 sodium cromoglycate as the internal standard. Compounds were extracted from 1.0 ml of lithium heparin plasma by methanol elution of C18 solid-phase extraction cartridges. The dried residue was reconstituted with 100 microl of 0.01 N HCl. and 30 microl was injected onto the LC-MS-MS system. Chromatographic separation was achieved on a C8 (3.5 microm) column with an isocratic mobile phase of methanol-water-0.5 M ammonium acetate (35:64.8:0.2, v/v/v). The analytes were detected with a PE Sciex API 3000 mass spectrometer using turbo ion spray with positive ionization. Ions monitored in the multiple reaction monitoring (MRM) mode were m/z 469.2 (precursor ion) to m/z 245.1 (product ion) for SCG and m/z 473.2 (precursor ion) to m/z 247.1 (product ion) for 13C4 SCG (I.S.). The average recoveries of SCG and the I.S. from human plasma were 91 and 87%, respectively. The low limit of quantitation was 0.100 ng/ml. Results from a 4-day validation study demonstrated excellent precision (C.V.% values were between 1.9 and 6.5%) and accuracy (-5.4 to - 1.2%) across the calibration range of 0.100-50.0 ng/ml.

  15. Tomographic shadowgraphy for spray diagnostics

    OpenAIRE

    Klinner, Joachim; Willert, Christian

    2011-01-01

    This contribution introduces 3-D shadowgraphy which is capable of resolving the placement of the liquid phase within a certain spray volume both spatially and temporally. The method is based on a multiple view camera setup and inline illumination provided by current pulsed LEDs. The quality of spray reconstruction was investigated using experimental data from multiple view shadowgraphs of hollow cone and flat fan water sprays. After calibration and determination of a 3-D mapping f...

  16. Ignition of Liquid Fuel Spray and Simulated Solid Rocket Fuel by Photoignition of Carbon Nanotube Utilizing a Camera Flash

    Science.gov (United States)

    2011-12-01

    Badakhshan A1 , Danczyk S. A.2, Wirth D.3 and Pilon L. 3 Abstract We have studied the ignition of fuel sprays and simulated solid rocket fuels (SRF...photoignition of solid oxidizer/CNT mixtures exposed to a flash of light. The flash source was a commercial studio flash lamp with a rated maximum

  17. Numerical modelling of fuel sprays

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, C.

    1999-06-01

    The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction between the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. The use of numerical calculations is an important tool to better understand these complex interacting phenomena. This thesis reports on the numerical modelling of fuel sprays in non-reacting cases using an own developed spray module. The spray module uses the stochastic parcel method to represent the spray. The module was made in such manner that it could by coupled with different gas flow solver. Results obtained from four different gas flow solvers are presented in the thesis, including the use of two different kinds of turbulence models. In the first part the spray module is coupled with a k-{eta} based 2-D cylindrical gas flow solver. A thorough sensitivity analysis was performed on the spray and gas flow solver parameters, such as grid size dependence and sensitivity to initial values of k-{eta}. The results of the spray module were also compared to results from other spray codes, e.g. the well known KIVA code. In the second part of this thesis the spray was injected into a turbulent and fully developed crossflow studied. The spray module was attached to a LES (Large Eddy Simulation) based flow solvers enabling the study of the complex structures and time dependent phenomena involved in spray in crossflows. It was found that the spray performs an oscillatory motion and that the Strouhal number in the wake was about 0.1. Different spray breakup models were evaluated by comparing with experimental results 66 refs, 56 figs

  18. Ligament-mediated spray formation

    NARCIS (Netherlands)

    Villermaux, E.; Marmottant, Ph.; Duplat, J.

    2004-01-01

    The spray formed when a fast gas stream blows over a liquid volume presents a wide distribution of fragment sizes. The process involves a succession of changes of the liquid topology, the last being the elongation and capillary breakup of ligaments torn off from the liquid surface. The coalescence o

  19. Sensors in Spray Processes

    Science.gov (United States)

    Fauchais, P.; Vardelle, M.

    2010-06-01

    This paper presents what is our actual knowledge about sensors, used in the harsh environment of spray booths, to improve the reproducibility and reliability of coatings sprayed with hot or cold gases. First are described, with their limitations and precisions, the different sensors following the in-flight hot particle parameters (trajectories, temperatures, velocities, sizes, and shapes). A few comments are also made about techniques, still under developments in laboratories, to improve our understanding of coating formation such as plasma jet temperature measurements in non-symmetrical conditions, hot gases heat flux, particles flattening and splats formation, particles evaporation. Then are described the illumination techniques by laser flash of either cold particles (those injected in hot gases, or in cold spray gun) or liquid injected into hot gases (suspensions or solutions). The possibilities they open to determine the flux and velocities of cold particles or visualize liquid penetration in the core of hot gases are discussed. Afterwards are presented sensors to follow, when spraying hot particles, substrate and coating temperature evolution, and the stress development within coatings during the spray process as well as the coating thickness. The different uses of these sensors are then described with successively: (i) Measurements limited to particle trajectories, velocities, temperatures, and sizes in different spray conditions: plasma (including transient conditions due to arc root fluctuations in d.c. plasma jets), HVOF, wire arc, cold spray. Afterwards are discussed how such sensor data can be used to achieve a better understanding of the different spray processes, compare experiments to calculations and improve the reproducibility and reliability of the spray conditions. (ii) Coatings monitoring through in-flight measurements coupled with those devoted to coatings formation. This is achieved by either maintaining at their set point both in-flight and

  20. Characteristics of liquid jet atomization across a high-speed airstream. III - Breakup process of liquid jet and internal structure of spray

    Science.gov (United States)

    Oda, Tetsuya; Hiroyasu, Hiroyuki; Nishida, Keiya

    1993-04-01

    To elucidate deformation and breakup processes of a liquid jet across an airstream, tomograms of the liquid jet were taken by means of the laser light sheet method. In this method, fluorescent dye, Eosine-Y, was contained in the injected water, and the liquid jet was illuminated by the Nd:YAG laser light sheet. There are two types of atomization mechanisms. In the first mechanism, a horizontal section of the liquid column is distorted into a bow shape, and there exists a cavity without drops behind the liquid column. Small drops are produced at both tips of the bow. The continuous length and the width of the liquid column were measured from the tomograms. In the second mechanism, in which velocities of both the airstream and the injecting liquid are low, the liquid column is distorted in a snakelike shape and drops are produced near the tip of the liquid column.

  1. Application of chemicals to substrates without the use of liquids: Proof of concepts for powder spray gun and fluidized bed solid-on- solid (SOS) processing of textiles, and continued research in textile xerography printing, solid shade coloration and electrostatic liquid spray SOS finishing of fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Cook, F.L.; Carr, W.W.; Tincher, W.C.; Sikorski, M.

    1990-09-28

    The first two years of research under DOE Contract No. FG05-84CE40702 were devoted toward developing processes whereby certain chemicals could be applied to textiles without the use of water, mainly concentrating on powder deposition techniques. The approach was to identify powder-based processes in other industry sectors (mainly the metals and paper industries) that possessed the potential to be adapted to continuous textile manufacturing lines. The adapted textile processes were classified under the general category of solid-on-solid (SOS) processes, since no liquid water was required, and 100% of the chemical materials applied to the substrate remained with it into final product manufacture. The current research focused on several areas of chemical treatment: yarn slashing, textile xerography printing, binding of nonwovens, fluoropolymer barrier finishing, and liquid spray and finishing. Several of these areas were sufficiently developed in the first phase to allow full-scale, proof-of-concept trials to be conducted at industrial sites in the third and fourth years of the project. Other areas were identified and preliminary investigations conducted in the first phase, but were largely left for full development in the reported phase, e.g., liquid spray finishing of 100% solids formulations. This report discusses work in each area of chemical treatment.

  2. Effect of Liquid Feed-Stock Composition on the Morphology of Titanium Dioxide Films Deposited by Thermal Plasma Spray.

    Science.gov (United States)

    Adán, C; Marugán, J; van Grieken, R; Chien, K; Pershin, L; Coyle, T; Mostaghimi, J

    2015-09-01

    Titanium dioxide coatings were deposited on the surface of titanium foils by Thermal Plasma Spray (TPS) process. Three different TiO2 coatings were prepared using the commercial TiO2-P25 nanopowder and titanium isopropoxide precursor solution as feed-stocks. Structure and morphology of the TiO2-P25 powder and the plasma sprayed coatings were analyzed by X-ray diffraction (XRD), Raman spectroscopy, N2 adsorption-desorption isotherms, UV-visible spectroscopy and Scanning Electron Microscopy (SEM). XRD and Raman results indicate that the TiO2 coatings were composed of an anatase/rutile mixture that is conditioned by the suspension composition used to be sprayed. Coatings prepared from TiO2-P25 nanoparticles in water suspension (NW-P25) and titanium isopropoxide solution suspension (NSP-P25) are incorporated into the coatings without phase transformation and their anatase/rutile ratio percentage remains very similar to the starting TiO2-P25 powder. On the contrary, when titanium isopropoxide solution is used for spraying (SP), the amount of rutile increases in the final TiO2 coating. SEM analysis also reveals different microstructure morphology, coating thickness, density and porosity of the three TiO2 films that depend significantly on the type of feed-stock employed. Interestingly, we have observed the role of titanium isopropoxide in the formation of more porous and cohesive layers of TiO2. The NSP-P25 coating, prepared with a mix of titanium isopropoxide solution based on TiO2 nanoparticles, presents higher deposition efficiencies and higher coating thickness than the film prepared with nanoparticles suspended in water (NW-P25) or with titanium isopropoxide solutions (SP). This is due to the precursor solution is acting as the cement between TiO2 nanoparticles, improving the cohesive strength of the coating. In sum, NSP-P25 and NW-P25 coatings display a good photocatalytic potential, based on their light absorption properties and mechanical stability. Band gap of

  3. Effect of confinement on breakup of planar liquid sheets sandwiched between two gas streams and resulting spray characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Sujit [Mechanical Engineering Department, National Institute of Technology, Silchar (India); Mukhopadhyay, Achintya [Mechanical Engineering Department and National Centre for Combustion Research and Development, Indian Institute of Technology Madras, Chennai – 600036 (India); Datta, Amitava [Power Engineering Department, Jadavpur University, Kolkata – 700098 (India); Sarkar, Soumalya; Sen, Swarnendu, E-mail: sujitnath2008@gmail.com [Mechanical Engineering Department, Jadavpur University, Kolkata – 700032 (India)

    2014-02-01

    Breakup of a planar liquid sheet in the presence of confining walls has been investigated using nonlinear stability analysis. The gas streams and the liquid sheet sandwiched between them are considered to be moving. Temporal stability analysis has been done for both sinuous and varicose modes of disturbance. The results show the clear influence of the proximity of confining walls on the stability and breakup of liquid sheets, particularly for the varicose mode where satellite drops are predicted for certain ranges of parameters. The presence of wall leads to shorter breakup lengths but larger drop sizes. (paper)

  4. Droplets and sprays

    CERN Document Server

    Sazhin, Sergei

    2014-01-01

    Providing a clear and systematic description of droplets and spray dynamic models, this book maximises reader insight into the underlying physics of the processes involved, outlines the development of new physical and mathematical models, and broadens understanding of interactions between the complex physical processes which take place in sprays. Complementing approaches based on the direct application of computational fluid dynamics (CFD), Droplets and Sprays treats both theoretical and practical aspects of internal combustion engine process such as the direct injection of liquid fuel, subcritical heating and evaporation. Includes case studies that illustrate the approaches relevance to automotive applications,  it is also anticipated that the described models can find use in other areas such as in medicine and environmental science.

  5. Wind Tunnel and Field Evaluation of Drift from Aerial Spray Applications with Multiple Spray Formulations

    Science.gov (United States)

    2012-01-01

    movement of sprays from aerial sprays continues to be a major concern. Ongoing research and edu- cation efforts, new product developments , and adaption...emulsifiable con- centrate, a liquid flowable, and a water dispersable granule ), with and without a non-ionic surfactant and a crop oil, sprayed in a 52 m/s... Development of the Spray Drift Task Force Database for Aerial Applications,” Envir. Toxic. Chem., Vol. 21, No. 3, 2002, pp. 648–658. [14] Spanoghe, P

  6. Spray nozzle for fire control

    Science.gov (United States)

    Papavergos, Panayiotis G.

    1990-09-01

    The design of a spray nozzle for fire control is described. It produces a spray of gas and liquid having an oval transverse cross section and it comprises a mixing chamber with an oval transverse cross section adapted to induce a toroidal mixing pattern in pressurized gas and liquid introduced to the mixing chamber through a plurality of inlets. In a preferred embodiment the mixing chamber is toroidal. The spray nozzle produces an oval spray pattern for more efficient wetting of narrow passages and is suitable for fire control systems in vehicles or other confined spaces. Vehicles to which this invention may be applied include trains, armoured vehicles, ships, hovercraft, submarines, oil rigs, and most preferably, aircraft.

  7. High-performance liquid chromatography coupled to ion spray mass spectrometry for the determination of colchicine at ppb levels in human biofluids.

    Science.gov (United States)

    Tracqui, A; Kintz, P; Ludes, B; Rougé, C; Douibi, H; Mangin, P

    1996-01-26

    An original method based upon high-performance liquid chromatography coupled to ion spray mass spectrometry (HPLC-ISP-MS) has been developed for the identification and quantification of colchicine (COL) in human blood, plasma or urine. After single-step liquid-liquid extraction by dichloromethane at pH 8.0 using tofisopam (TOF) as an internal standard, solutes are separated on a 5-microns C18 Microbore (Alltech) column (250 x 1.0 mm, I.D.), using acetonitrile-2 mM NH4COOH, pH 3 buffer (75: 25, v/v) as the mobile phase (flow-rate 50 microliters/min). Detection is done by a Perkin-Elmer Sciex API-100 mass analyzer equipped with a ISP interface (nebulizing and curtain gas: N2, quality U; main settings: ISP, +4.0 kV; OR, +50 V; Q0, -10 V; Q1, -13 V; electron multiplier, +2.2 kV); MS data are collected as either total ion current (TIC, m/z 100-500 or 380-405), or selected ion monitoring (SIM) at m/z 400 and 383 for COL and TOF, respectively. COL mass spectrum shows a prominent molecular ion [M + H]+ at m/z 400. Increasing OR potential fails to provide a significant fragmentation. Retention times are 2.70 and 4.53 min for COL and TOF, respectively. The quantification method shows a good linearity (r = 0.998) over a concentration range from 5 to 200 ng/ml. The lower limit of detection in SIM mode is 0.6 ng/ml COL, making the method convenient for both clinical and forensic purposes.

  8. A novel high-performance liquid chromatography-electron spray ionization-mass spectrometry method for simultaneous determination of guggulsterones, piperine and gallic acid in Triphala guggulu

    Directory of Open Access Journals (Sweden)

    Ganesh Muguli

    2015-01-01

    Full Text Available "Triphalaguggulu0" is an important Ayurvedic formulation comprising of Guggulu, that is, Commiphora wightii (Arn. Bhandari as a base wherein powdered fruits of triphala, that is, Phyllanthus emblica L., Terminalia bellirica (Gaertn. Roxb and Terminalia chebula Retz, along with powdered fruit of Piper longum L. are compounded. This polyherbal preparation has been strongly recommended in chronic inflammation, piles, and fistula. However, due to the complexity of compound formulation standardization of commercial products is challenging. In the present communication marker-based standardization of "Triphalaguggulu" preparation using gallic acid (for triphala, piperine (for P. longum L. and guggulsterones (for guggulu is reported. These compounds of diverse chemistry were successfully separated on a Waters HR-C18 column by isocratic elution with methanol and water (80:20 v/v as mobile phase at the flow rate of 1.0 mL/min coupled with photodiode array detector. These optimal chromatographic conditions were used for simultaneous quantification of gallic acid, guggulsterones (E and Z and piperine in commercial samples by high-performance liquid chromatography-electron spray ionization-mass spectrometry and method was validated as per ICH guidelines.

  9. Potencial do soro de leite líquido como agente encapsulante de Bifidobacterium Bb-12 por spray drying: comparação com goma arábica Potential of liquid whey as the encapsulating agent of Bifidobacterium Bb-12 by spray drying: comparison with arabic gum

    Directory of Open Access Journals (Sweden)

    Fabiane Picinin de Castro-Cislaghi

    2012-09-01

    Full Text Available O objetivo do trabalho foi avaliar o potencial do soro de leite líquido como agente encapsulante de Bifidobacterium Bb-12 por spray drying, comparando-o com a goma arábica, a qual é tradicionalmente utilizada na tecnologia de microencapsulação. Foram determinados o rendimento da microencapsulação e a viabilidade das microcápsulas durante o armazenamento. Quando o soro de leite foi utilizado como agente encapsulante, o rendimento da microencapsulação foi maior e a viabilidade das células manteve-se elevada e constante durante doze semanas. O soro de leite apresentou-se como um eficiente agente encapsulante de Bifidobacterium por spray drying.The objective of this study was to evaluate the potential of liquid whey as the encapsulating agent Bifidobacterium Bb-12 by spray drying, compared with arabic gum, which is typically used in microencapsulation technology. The microencapsulation yield and viability during storage were determined. When the whey was used as the encapsulating agent, the microencapsulation yield was higher, and cell viability remained high and steady for twelve weeks. The whey was shown to be an effective encapsulating agent of Bifidobacterium by spray drying.

  10. Spray Evaporation of Different Liquids in a Drying Chamber--Effect on Flow, Heat and Mass Transfer Performances%干燥室中不同液体的喷雾蒸发对流动、传热、传质性能的影响

    Institute of Scientific and Technical Information of China (English)

    HUANG Lixin; Kurichi Kumar; A.S. Mujumdar

    2004-01-01

    Almost without exception literature data and modeling effort are understandably devoted to water as the sprayed liquid since it constitutes the most common liquid used in spray drying applications. In selected applications, however, the liquid making up the solution or suspension may not be water. The objective of this work is to examine the differences in flow patterns, thermal behavior and drying rates caused by different liquids having different thermo-physical properties spray into a spray dryer using a computational fluid dynamic model.Numerical experiments were carried out for water (base case), ethyl alcohol and isopropyl alcohol-the latter two as model non-aqueous liquids. The chamber geometry was cylinder type with a co-current axial pressure nozzle and also an axial central exit so that the configuration is two dimensional and axi-symmetric. It is shown that the liquid properties can have major influence on the thermal field, droplet trajectories, residence times and overall evaporation capacity when all parameters of the problem are held fixed. Deviations from the single phase turbulent airflow in the same chamber without spray are different for the three liquids examined.

  11. No Heat Spray Drying Technology

    Energy Technology Data Exchange (ETDEWEB)

    Beetz, Charles [ZoomEssence, Inc., Hebron, KY (United States)

    2016-06-15

    No Heat Spray Drying Technology. ZoomEssence has developed our Zooming™ spray drying technology that atomizes liquids to powders at ambient temperature. The process of drying a liquid into a powder form has been traditionally achieved by mixing a heated gas with an atomized (sprayed) fluid within a vessel (drying chamber) causing the solvent to evaporate. The predominant spray drying process in use today employs air heated up to 400° Fahrenheit to dry an atomized liquid into a powder. Exposing sensitive, volatile liquid ingredients to high temperature causes molecular degradation that negatively impacts solubility, stability and profile of the powder. In short, heat is detrimental to many liquid ingredients. The completed award focused on several areas in order to advance the prototype dryer to a commercial scale integrated pilot system. Prior to the award, ZoomEssence had developed a prototype ‘no-heat’ dryer that firmly established the feasibility of the Zooming™ process. The award focused on three primary areas to improve the technology: (1) improved ability to formulate emulsions for specific flavor groups and improved understanding of the relationship of emulsion properties to final dry particle properties, (2) a new production atomizer, and (3) a dryer controls system.

  12. Synthesis of Zn1- x Co x Al2O4 Spinel Nanoparticles by Liquid-Feed Flame Spray Pyrolysis: Ceramic Pigments Application

    Science.gov (United States)

    Betancur Granados, Natalia; Yi, Eongyu; Laine, Richard M.; Restrepo Baena, Oscar Jaime

    2016-01-01

    Zn1- x Co x Al2O4 ( x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) spinel nanoparticles were synthesized by a liquid-feed flame spray pyrolysis (LF-FSP) method by combusting metallorganic precursor solutions to produce nanopowders with precise composition control. The precursor solutions were aerosolized into a methane/oxygen flame where it was combusted in an oxygen-rich environment to result in nanopowders at a single step. The nanopowders were analyzed by x-ray diffraction, Fourier transform infrared spectroscopy, colorimetry, field emission scanning electron microscopy, transmission electron microscopy, and BET (Brunauer-Emmett-Teller) N2 adsorption. Results show formation of spherical nanopowders with specific surface areas of 42 m2/g to 50 m2/g, which correspond to average particle sizes of 26 nm to 31 nm. Single-phase materials were obtained with a high control of composition, which indicates that LF-FSP is an excellent method to produce mixed-metal oxides for applications in which powder homogeneity is crucial. The products were evaluated for ceramic pigment application, where the ratio of Zn to Co was gradually changed to observe the color change in the structure with the increase of cobalt concentration. The resulting pigments were calcined at 1200°C, which aimed to identify the color stability after a high-temperature process, whereby the colors were measured using the color space CIE L*a*b* under standardized light, D65. Finally, the powders were tested for ceramic decoration using transparent glazes and ceramic bodies. The application was carried out at 1250°C to evaluate the color performance after a decoration process.

  13. A Comprehensive Review on Fluid Dynamics and Transport of Suspension/Liquid Droplets and Particles in High-Velocity Oxygen-Fuel (HVOF Thermal Spray

    Directory of Open Access Journals (Sweden)

    Mehdi Jadidi

    2015-10-01

    Full Text Available In thermal spraying processes, molten, semi-molten, or solid particles, which are sufficiently fast in a stream of gas, are deposited on a substrate. These particles can plastically deform while impacting on the substrate, which results in the formation of well-adhered and dense coatings. Clearly, particles in flight conditions, such as velocity, trajectory, temperature, and melting state, have enormous influence on the coating properties and should be well understood to control and improve the coating quality. The focus of this study is on the high velocity oxygen fuel (HVOF spraying and high velocity suspension flame spraying (HVSFS techniques, which are widely used in academia and industry to generate different types of coatings. Extensive numerical and experimental studies were carried out and are still in progress to estimate the particle in-flight behavior in thermal spray processes. In this review paper, the fundamental phenomena involved in the mentioned thermal spray techniques, such as shock diamonds, combustion, primary atomization, secondary atomization, etc., are discussed comprehensively. In addition, the basic aspects and emerging trends in simulation of thermal spray processes are reviewed. The numerical approaches such as Eulerian-Lagrangian and volume of fluid along with their advantages and disadvantages are explained in detail. Furthermore, this article provides a detailed review on simulation studies published to date.

  14. Development and application of a high-speed planar laser-induced fluorescence imaging system to evaluate liquid and vapor phases of sprays from a multi-hole diesel fuel injector

    Science.gov (United States)

    Parrish, S. E.; Zink, R. J.

    2013-02-01

    A high-speed imaging system capable of acquiring elastic scattering images and planar laser-induced fluorescence (PLIF) images in a near-simultaneous fashion has been developed. Acquiring both elastic scattering and PLIF images enables the liquid phase to be discriminated from the vapor phase. High-speed imaging allows the temporal evolution of flow structures to be evaluated. Images of sprays from a multi-hole diesel fuel injector operating under engine-like conditions were acquired. The vapor phase images reveal intricate fluid dynamic structures that exhibit a high degree of variability, indicative of a turbulent gas jet.

  15. Algorithms for improving accuracy of spray simulation

    Institute of Scientific and Technical Information of China (English)

    ZHANG HuiYa; ZHANG YuSheng; XIAO HeLin; XU Bo

    2007-01-01

    Fuel spray is the pivotal process of direct injection engine combustion. The accuracy of spray simulation determines the reliability of combustion calculation. However, the traditional techniques of spray simulation in KIVA and commercial CFD codes are very susceptible to grid resolution. As a consequence, predicted engine performance and emission can depend on the computational mesh. The two main causes of this problem are the droplet collision algorithm and coupling between gas and liquid phases. In order to improve the accuracy of spray simulation, the original KIVA code is modified using the cross mesh droplet collision (CMC) algorithm and gas phase velocity interpolation algorithm. In the constant volume apparatus and D.I. Diesel engine, the improvements of the modified KIVA code in spray simulation accuracy are checked from spray structure, predicted average drop size and spray tip penetration, respectively. The results show a dramatic decrease in grid dependency. With these changes, the distorted phenomenon of spray structure is vanished. The uncertainty in predicted average drop size is reduced from 30 to 5 μm in constant volume apparatus calculation, and the uncertainty is further reduced to 2 μm in an engine simulation. The predicted spray tip penetrations in engine simulation also have better consistency in medium and fine meshes.

  16. 叶面喷施SOD液肥对小麦生长和产量构成因素的影响%Effect of Foliage Spraying SOD Liquid Fertilizer on Wheat Growth and Yield Components

    Institute of Scientific and Technical Information of China (English)

    王春虎; 杨文平; 李辉; 王俊萍

    2012-01-01

    为了进一步研究SOD液肥对小麦生长发育和产量构成因素的影响,试验利用不同浓度SOD液肥在小麦拔节期对其进行叶面喷施试验,稀释浓度分别为100、300、500倍液,以喷施等量清水作对照.结果显示:①喷施SOD液肥能促进小麦光合作用及干物质积累,达到增产效果;②在拔节期叶面喷施3种不同浓度的SOD液肥有不同的肥效,处理2比对照增产19.55%,处理1比对照增产13.13%,处理3比对照增产6.28%.表明叶面喷施SOD液肥是一项简单易行、回报率相对较高的增产措施,在小麦高产高效栽培方面属一项实用技术,有较高的推广应用价值.%Different concentration of SOD liquid fertilizer (CK, 100,300,500 times dilution) was applied on wheat in jointing stage by foliage spraying in order to study its effects on wheat growth and yield components. The results showed that spraying SOD liquid fertilizer could promote the photosynthesis and dry matter accumulation which resulted in yield increasing. Different concentration of SOD liquid fertilizer had different effect on yield, as the yield was increased by 13.13%, 19.55% and 6.28% compared with CK in 100, 300, 500 times dilution of SOD liquid fertilizer treatment respectively. Foliage spraying of liquid fertilizer SOD was a simple stimulation with high input-output ratio.

  17. Study on the influence factors of the absorption liquid sprayed governance of sulfureted hydrogen in coal mine%喷洒吸收液治理煤矿硫化氢的影响因素研究

    Institute of Scientific and Technical Information of China (English)

    董琦

    2015-01-01

    Theoretical analysis of the absorption liquid sprayed neutralization reaction mechanism of hydrogen sulfide, Through laboratory simulation experiment and the influence of single factor on the absorption efficiency of hydrogen sulfide that influence of various factors on the absorption efficiency of hydrogen sulfide, in the orthogonal test results contrast, found that regular consistent. The experimental results obtained for the further optimization of the working face, the theory basis of spraying high pressure hydrogen sulfide absorption liquid provided by the treatment of hydrogen sulfide.%理论分析了喷洒吸收液中和反应硫化氢机理,通过实验室模拟单因素对硫化氢吸收效率的影响实验得出各因素对硫化氢吸收效率的影响规律,于正交试验结果对比,发现规律前后一致。本实验结果的得出,对进一步优化工作面高压喷洒硫化氢吸收液治理硫化氢提供的理论依据。

  18. 减肥保健食品中奥利司他的HPLC-UV-ESI-MS的测定%Determination of Orlistat in health food for controlling body weight by high performance liquid chromatography/electros pray spectrometry

    Institute of Scientific and Technical Information of China (English)

    肖松; 朱小兰; 陈波; 姚守拙; 王竹天; 杨大进; 韩宏伟

    2006-01-01

    目的建立减肥保健食品中奥利司他的高效液相色谱/质谱联用检测方法.方法以含有甲酸的乙腈和水作为流动相,在反相C8柱上分离,以质谱定性,紫外定量进行检测.结果在实验条件下可以有效的扣除食品中其他成分的干扰,从而对奥利司他进行检测.结论本方法可以快速,准确地测定减肥保健食品中奥利司他的含量.

  19. Studies on Ultrasonic Spray Dryer (1)

    OpenAIRE

    井上, 昌夫

    1981-01-01

    Author has initiated research and development activities for a epochal ultrasonic spray dryer in order to obtain large quantities of droplets in uniform diameters, from which a practically applicable ultrasonic spray dryer would possibly be developed. Since the time Wood, Loomis et al. reported their experiments on atomization of liquids by ultrasonic power, research in this field is now widely attempted in many countries. In Japan, this field is being investigated by Ohno et al. Chiba, and M...

  20. [Equipment for spray-freezing in ophthalmology].

    Science.gov (United States)

    Anders, M; Matthes, R

    1991-05-01

    The authors discuss the theoretical background of the method of spray/freezing for destructive processes and their advantages. They demonstrate a cryo-apparatus IKG 3 for liquid nitrogen which is part of the Dresden equipment and was elaborated by the department for cryomedicine of the "Carl Gustav Carus" Academy in cooperation with the Technical University in Dresden. The apparatus produces a fine dispensable spray of the cooling mixture and permits treatment even of small tissue areas.

  1. EFFECT OF NOZZLE FAN ANGLE ON SPRAYS IN GAS-SOLID RISER FLOW

    Institute of Scientific and Technical Information of China (English)

    Muhammad; M.; R.; Qureshi; Chao; Zhu; Chao-Hsin; Lin; Liang-Shih; Fan

    2006-01-01

    A three-dimensional simulation study is performed for investigating the hydrodynamic behaviors of a cross-flow liquid nitrogen spray injected into an air-fluidized catalytic cracking (FCC) riser of rectangular cross-section. Rectangular nozzles with a fixed aspect ratio but different fan angles are used for the spray feeding. While our numerical simulation reveals a generic three-phase flow structure with strong three-phase interactions under rapid vaporization of sprays, this paper tends to focus on the study of the effect of nozzle fan angle on the spray coverage as well as vapor flux distribution by spray vaporization inside the riser flow. The gas-solid (air-FCC) flow is simulated using the multi-fluid method while the evaporating sprays (liquid nitrogen) are calculated using the Lagrangian trajectory method, with a strong two-way coupling between the Eulerian gas-solid flow and the Lagrangian trajectories of spray. Our simulation shows that the spray coverage is basically dominated by the spray fan angle. The spray fan angle has a very minor effect on spray penetration. The spray vaporization flux per unit area of spray coverage is highly non-linearly distributed along the spray penetration. The convection of gas-solid flow in a riser leads to a significant downward deviation of vapor generated by droplet vaporization, causing a strong recirculating wake region in the immediate downstream area of the spray.

  2. Spray calcination of nuclear wastes

    Energy Technology Data Exchange (ETDEWEB)

    Bonner, W.F.; Blair, H.T.; Romero, L.S.

    1976-01-01

    The spray calciner is a relatively simple machine; operation is simple and is easily automated. Startup and shutdown can be performed in less than an hour. A wide variety of waste compositions and concentrations can be calcined under easily maintainable conditions. Spray calcination of all commercial fuel reprocessor high-level liquid wastes and mixed high and intermediate-level wastes have been demonstrated. Wastes have been calcined containing over 2M sodium. Thus waste generated during plant startup and shutdown can be blended with normal waste and calcined. Spray calcination of ILLW has also been demonstrated. A remotely replaceable atomizing nozzle has been developed for use in plant scale equipment. The 6 mm (0.25 inch) orifice and ceramic tip offer freedom from plugging and erosion thus nozzle replacement should be required only after several months operation. Calciner capacity of over 75 l/h (20 gal/h) has been demonstrated in pilot scale equipment. Sintered stainless steel filters are effective in deentraining over 99.9 percent of the solids that result from calcining the feedstock. Since such a small amount of radionuclides escape the calciner the volume of recycle required from the effluent treatment system is very small. The noncondensable off-gas volume is also low, less than 0.5 m/sup 3//min (15 scfm) for a liquid feedrate of 75 l/hr (20 gal/hr). Calcine holdup in the calciner is less than 1 kg, thus the liquid feedrate is directly relatable to calcine flowrate. The calcine produced is very fine and reactive. Successful remote operation and maintenance of a heated wall spray calciner has been demonstrated while processing actual high-level waste. During these operations radionuclide volatilization from the calciner was acceptably low. 8 figures. (DLC)

  3. 喷雾接种生物颗粒两相流及其对菌种活性的影响%Solid-liquid two-phase flow of microbial particle spraying inoculation and its influence on microbial viability

    Institute of Scientific and Technical Information of China (English)

    李建华; 郑加强; 余果

    2014-01-01

    hermetic bioreactor. After sterilization, the nozzle of the inoculation spraying system can spray the microbial strain on the solid substrate, to realize sterilizing, cooling, inoculation, and fermentation inside one solid-state fermentation bioreactor. The microbial viability may be determined by the spraying system of the spraying inoculation of pure-culturing solid-state fermentation that could directly result in the death of the microorganisms. The solid-liquid two-phase flow of the microbial particle spray inoculation fluid system was analyzed. Fluid characteristics of the two-phase flow composed of microorganisms and sterile water was discussed, and the forced state of the microorganism particles was also analyzed. The energy component was deduced, and the theoretical basis, reliability, and practicability of the energy dissipation rate which could quantify the microbial particles’ damage within comprehensive hydrodynamic stresses were also discussed and analyzed. The effect of nozzle type and spraying parameters on the results of the spraying inoculation was studied by a simulation using FLUENT. A user-defined function was created in FLUENT to compute the energy dissipation rate from the flow field information. By setting reasonable boundary conditions and initial conditions, simulations of a hollow cone nozzle’s flow field of the pressure and energy dissipation rate were conducted for each size of the nozzle and the experimental inlet pressure. A set of spraying inoculation experimental flow devices was designed and manufactured. At the same time, an appropriate test method was determined. Microzyme was selected as the microbial particle in the spraying inoculation experimental system because it was easy to separate the living microzyme from the dead microzyme. It could be dyed with Loeffler basic methylene blue dye and the living microzyme with a strong reducing ability is colorless and the dead or weak dying microzyme is blue under microscope. Experimental

  4. Hair spray poisoning

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

  5. 甜玉米酶解液喷雾干燥工艺的研究%Study on the spray drying technology of sweet corn enzymolysis liquid

    Institute of Scientific and Technical Information of China (English)

    李春梅; 迟玉杰; 王丹

    2012-01-01

    对甜玉米酶解液的喷雾干燥加工工艺进行了研究,确定了其工艺参数。根据喷雾效果,确定了麦芽糊精为助干剂。在单因素实验的基础上设计了四因素三水平的响应面实验,以麦芽糊精添加量、进口温度、物料流量、热风流量为考察因素.以出粉率为考察指标,对实验数据拟合得到的回归方程进行了统计检验和分析。最佳喷雾干燥工艺参数组合为:麦芽糊精添加量68.5%,进口温度160℃,物料流量743mL/h,热风流量0.5m3/min。在此干燥条件下,出粉率最高为48.65%.并在相同条件下进行了验证实验,实验值在95%的置信区间内很好地符合预测值。%The spray drying process of sweet corn hydrolysate was studied,and the process parameters were determined. On the basis of the spray drying effect,the malt dextrin was determined as drying agent. Response surface experiment with four factors and three levels was designed on the base of the single factor experiment results. Maltodextrin addition,inlet air temperature,the material flow,hot air flow were designed as inspecting factors,and yield rate of powder was designed as inspecting index. The regression equation was tested and anaylsed by statistical method. The optimum conditions for the spray drying:Maltodextrin addition was 68.5%, inlet air temperature was 160℃,the material flow was 743mUh, hot air flow was 0.5m3/min. In this experimental condition,the highest yield rate of the products was 48.65%,and the results were verified under this experiment condition ,test values at the 95% confidence interval was well consistent with the predicted value.

  6. Effect of foliar spray from seaweed liquid fertilizer of Ulva reticulata (Forsk.) on Vigna mungo L. and their elemental composition using SEM- energy dispersive spectroscopic analysis

    Institute of Scientific and Technical Information of China (English)

    G Ganapathy Selvam; K Sivakumar

    2013-01-01

    Objective: To identify the effect of seaweed liquied fertilizer (SLF) of Ulva reticulata, as biochemical characteristics of Vigna mungo as well as leaf morphometric analysis such as epidermal and stomata cell variation and distribution of minerals in the leaf. Methods:Experiments were conducted on black gram to study the potential green alga of Ulva reticulata as a biofertilizer. The seeds were sown in soil and SLF were added to soil bed in five different concentrations separately (1%, 2%, 4%, 6% and 8% w/v). Results: Seaweed extract was applied as a foliar spray, the SLF treated plants show maximum growth in 2% of SLF among the various experimental concentrations as well as control. Biochemical profiles like chlorophyll a and b, protein, sugar and starch were found to be higher at 2%. A significant increase in the number of epidermal and stomata cells were observed in 2% SLF treated plants. Whereas at higher concentrations of SLF such as 4%, 6%, and 8% the values of all the parameters were significantly decreased than in the control group. Further the leaf of 2% SLF treated V. mungo have subjected to Scanning Electron Microscopy with Energy Dispersive Spectroscopic analysis it reveals that thepresence of ten elements in the following order: Ca>P>N>Na>K>Mg>Mn>S>Fe>Zn in treated and Ca>N>P>Na>Mg>Mn>K>Zn>S>Fe in control plant. The data generated from study reveal that SLF of U. reticulatea could be used as foliar spray at low concentration of 2% to maximize the growth and yield of V. mungo and also increase the number of stomata in the leaf. Conclusion:The main objective of study result would be the manorial requirement for organic forming and serve as a cost effective ecofriendliness for sustainable agriculture and environment.

  7. Mobile robot based electrostatic spray system for controlling pests on cotton plants in Iraq

    Science.gov (United States)

    Al-Mamury, M.; Manivannan, N.; Al-Raweshidy, H.; Balachandran, W.

    2015-10-01

    A mobile robot based electrostatic spray system was developed to combat pest infestation on cotton plants in Iraq. The system consists of a charged spray nozzle, a CCD camera, a mobile robot (vehicle and arm) and Arduino microcontroller. Arduino microcontroller is used to control the spray nozzle and the robot. Matlab is used to process the image from the CCD camera and to generate the appropriate control signals to the robot and the spray nozzle. COMSOL multi-physics FEM software was used to design the induction electrodes to achieve maximum charge transfer onto the fan spray liquid film resulting in achieving the desired charge/mass ratio of the spray. The charged spray nozzle was operated on short duration pulsed spray mode. Image analysis was employed to investigate the spray deposition on improvised insect targets on an artificial plant.

  8. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

  9. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight, a

  10. High Speed Imaging of Diesel Fuel Sprays

    Science.gov (United States)

    Jackson, Ja'kira; Bittle, Joshua

    2016-11-01

    Fuel sprays primarily serve as methods for fuel distribution, fuel/air mixing, and atomization. In this research, a constant pressure flow rig vessel is being tested at various pressures and temperatures using n-heptane. The experiment requires two imaging techniques: color Schlieren and Mie-scatter. Schlieren captures density gradients in a spray which includes both liquid and vapor phases while Mie-scatter is only sensitive to the liquid phase of the fuel spray. Essentially, studies are mainly focused on extracting the liquid boundary from the Schlieren to possibly eliminate the need for acquiring the Mie-Scatter technique. Four test conditions (combination of low and high pressure and temperatures) are used in the application to attempt to find the liquid boundary independent of the Mie-scatter technique. In this pursuit the following methods were used: a color threshold, a value threshold, and the time variation in color. All methods provided some indication of the liquid region but none were able to capture the full liquid boundary as obtained by the Mie-scatter results. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

  11. Structure of high-speed sprays

    Science.gov (United States)

    Bracco, Frediano V.

    1995-01-01

    This work covered both measurements and computations and its results are documented in eight appendices. Measurements were made of drop velocity in vaporizing, steady, full-cone sprays and of drop velocity and drop size in non-vaporizing steady full-cone sprays. In similar conditions, measurements had previously been made of the intact core and of the size of the drops in the immediate vicinity of the injector, thus generating an extensive set of data which were particularly useful for the assessment and the development of multidimensional models of engine sprays. On the computational side, a line source technique was introduced to simulate the intact-core in engine sprays and two extensive numerical studies were carried out to explain the strong anisotropy of the drop velocity fluctuations that had been found in the measurements. In another interesting and timely study, the accuracy of the stochastic method of computing drop collisions and coalescence (which is the one universally used) was assessed by corresponding deterministic computations (more accurate but much more time consuming). It was concluded that the accuracy of the stochastic method in practical computations can be wanting. Finally, a numerical study of the structure of hollow-cone sprays was initiated that has since been followed by significant experimental and computational work on liquid-only and air-assisted hollow-cone injectors and sprays.

  12. Guest Editorial Particle Sizing And Spray Analysis

    Science.gov (United States)

    Chigier, Norman; Stewart, Gerald

    1984-10-01

    The measurement of particle size and velocity in particle laden flows is a subject of interest in a variety of industrial applications. In combustion systems for electricity generation, industrial processes and heating, and transportation, where liquid and solid fuels are injected into air streams for burning in furnaces, boilers, and gas turbine and diesel engines, the initial size and velocity distributions of particles are determining factors in the overall combustion efficiency and the emission of pollutants and particulates. In the design of injectors and burners for the atomization of liquid fuels, a great deal of attention is being focused on developing instrumentation for the accurate measurement of size and velocity distributions in sprays as a function of space and time. Most recent advances in optical engineering techniques using lasers for particle measurement have focused on detailed spray characterization, where there is a major concern with spherical liquid droplets within the size range of 1 to 500 μm in diameter, with droplet velocities within the range of 1 to 100 m/s, and the requirement for making in situ measurements of moving particles by nonintrusive optical probes. The instruments being developed for spray analysis have much wider applications. These include measurement in particle laden flows encountered in a variety of industrial processes with solid particles in gas and liquid streams and liquid particles in gas streams. Sprays used in agriculture, drying, food processing, coating of materials, chemical processing, clean rooms, pharmaceuticals, plasma spraying, and icing wind tunnels are examples of systems for which information is being sought on particle and fluid dynamic interactions in which there is heat, mass, and momentum transfer in turbulent reacting flows.

  13. An Experimental Study on the Macroscopic Spray Characteristics of Biodiesel and Diesel in a Constant Volume Chamber

    Directory of Open Access Journals (Sweden)

    Hongzhan Xie

    2015-06-01

    Full Text Available The objective of this study was to investigate the macroscopic spray characteristics of different 0%–100% blends of biodiesel derived from drainage oil and diesel (BD0, BD20, BD50, BD80, BD100, such as spray tip penetration, average tip velocity at penetration, spray angle, average spray angle, spray evolution process, spray area and spray volume under different injection pressures (60, 70, 80, 90, 100 MPa and ambient pressures (0.1, 0.3, 0.5, 0.7, 0.9 MPa using a common rail system equipped with a constant volume chamber. The characteristic data was extracted from spray images grabbed by a high speed visualization system. The results showed that the ambient pressure and injection pressure had significant effects on the spray characteristics. As the ambient pressure increased, the spray angle increased, while the spray tip penetration and the peak of average tip velocity decreased. As the injection pressure increased, the spray tip penetration, spray angle, spray area and spray volume increased. The increasing blend ratio of biodiesel brought about a shorter spray tip penetration and a smaller spray angle compared with those of diesel. This is due to the comparatively higher viscosity and surface tension of biodiesel, which enhanced the friction effect between fuel and the injector nozzle surface and inhibited the breakup of the liquid jet.

  14. Plasma-Spray Metal Coating On Foam

    Science.gov (United States)

    Cranston, J.

    1994-01-01

    Molds, forms, and other substrates made of foams coated with metals by plasma spraying. Foam might be ceramic, carbon, metallic, organic, or inorganic. After coat applied by plasma spraying, foam left intact or removed by acid leaching, conventional machining, water-jet cutting, or another suitable technique. Cores or vessels made of various foam materials plasma-coated with metals according to method useful as thermally insulating containers for foods, liquids, or gases, or as mandrels for making composite-material (matrix/fiber) parts, or making thermally insulating firewalls in automobiles.

  15. Uniform-droplet spray forming

    Energy Technology Data Exchange (ETDEWEB)

    Blue, C.A.; Sikka, V.K. [Oak Ridge National Lab., TN (United States); Chun, Jung-Hoon [Massachusetts Institute of Technology, Cambridge, MA (United States); Ando, T. [Tufts Univ., Medford, MA (United States)

    1997-04-01

    The uniform-droplet process is a new method of liquid-metal atomization that results in single droplets that can be used to produce mono-size powders or sprayed-on to substrates to produce near-net shapes with tailored microstructure. The mono-sized powder-production capability of the uniform-droplet process also has the potential of permitting engineered powder blends to produce components of controlled porosity. Metal and alloy powders are commercially produced by at least three different methods: gas atomization, water atomization, and rotating disk. All three methods produce powders of a broad range in size with a very small yield of fine powders with single-sized droplets that can be used to produce mono-size powders or sprayed-on substrates to produce near-net shapes with tailored microstructures. The economical analysis has shown the process to have the potential of reducing capital cost by 50% and operating cost by 37.5% when applied to powder making. For the spray-forming process, a 25% savings is expected in both the capital and operating costs. The project is jointly carried out at Massachusetts Institute of Technology (MIT), Tuffs University, and Oak Ridge National Laboratory (ORNL). Preliminary interactions with both finished parts and powder producers have shown a strong interest in the uniform-droplet process. Systematic studies are being conducted to optimize the process parameters, understand the solidification of droplets and spray deposits, and develop a uniform-droplet-system (UDS) apparatus appropriate for processing engineering alloys.

  16. 旋转喷吹除气箱中气液两相流动行为的数值研究%Numerical Study on Gas-liquid Flow Behavior in Rotating Spray Degassing Tank

    Institute of Scientific and Technical Information of China (English)

    孙会

    2011-01-01

    The Eulerian two-fluid model incorporating with the multiple reference frame method was adopted to simulate the gas-liquid flow field in rotating spray degassing tank, and a new modeling method based on the computational domain was proposed to describe the liquid top surface. The influences of factors on the gas-liquid flow behavior were also investigated. The results show that the modeling method for describing the liquid top surface is feasible. With the decrease of bubble size and the increase of rotational speed, the purging time and melt/bubble interface increase, and purge gas distribution in degassing tank improves, which are beneficial to the refinement of melt. In addition, using the cylindrical tank, the purge gas mainly congregates around the rotational shaft, and swirl always occurs, which is disadvantage to the degassing of hydrogen.%利用欧拉模型和多参考坐标系法对旋转喷吹除气箱中的气液两相流场进行数值模拟,提出基于计算域的选取获取自由液面波动的建模方法,并考察了不同因素对除气箱内气液两相流动行为产生的影响.结果表明.提出的获取自由液面波动的建模方法是可行的.随气泡直径的减小、搅拌转速的增加,气体在除气箱中停留时间延长.与铝熔体接触面积增大,气体在除气箱中的分布得到改善,有利于铝熔体的净化.此外,采用圆柱形除气箱,气体大多聚集在转杆周围,且易发生打漩现象,这对铝熔体的除氢不利.

  17. Effect of nebulizer/spray chamber interfaces on simultaneous, axial view inductively coupled plasma optical emission spectrometry for the direct determination of As and Se species separated by ion exchange high-performance liquid chromatography

    Science.gov (United States)

    Gettar, Raquel T.; Smichowski, Patricia; Garavaglia, Ricardo N.; Farías, Silvia; Batistoni, Daniel A.

    2005-06-01

    Different nebulizer/expansion chamber combinations were evaluated to assess their performance for sample introduction in the direct coupling with an axial view inductively coupled plasma multielement spectrometer for on-line determination of As and Se species previously separated by ion exchange-high performance liquid chromatography. The column effluents were injected into the plasma without prior derivatization. The instrument operation software was adapted for data acquisition and processing to allow multi-wavelength recording of the transient chromatographic peaks. After optimization of the chromatographic operating conditions, separation of mixtures of inorganic As and Se species, and of inorganic and two organic As species (monomethylarsonic and dimethylarsinic acids), was achieved with excellent resolution. Species discrimination from mixtures of As and Se oxyanions was further improved by the simultaneous element detection at specific analytical wavelengths. Three nebulizers and three spray chambers, employed in seven combinations, were tested as interfaces. Concentric nebulizers associated to a glass cyclonic chamber appear most suitable regarding sensitivity and signal to noise ratio. Measured element detection limits (3 σ) were around 10 ng ml - 1 for all the species considered, making the method a viable alternative to similar procedures that employ volatile hydride generation previous to sample injection into the plasma. Analytical recoveries both for inorganic and organic species ranged between 92 and 107%. The method was demonstrated to be apt for the analysis of surface waters potentially subjected to natural contamination with arsenic.

  18. 影响铝型材静电喷涂用粉末涂料流动性因素探讨%Discussing on the Factors Effecting Liquidity Electrostatic Powder Spraying in Aluminium Profile

    Institute of Scientific and Technical Information of China (English)

    刘宏; 向寓华; 刘碧雄

    2011-01-01

    The detecting liquidity principle of powder coating and estimate index had been introduced. The effecting factors had been discussed too form resinous polymer, powder particle shape and size, fluidization air quality, spraying environment humidity, coating fluidization additive etc. The relevant process control parameters and measures had been provided. Experimental results had been demonstrated the better process parameters for liquidity of powder coating: resin molecular weight 2000 to 5000, Tg 50~65 ℃, spherical particle shape, size distribution 20~80 μm, fluidization air pressure 0.01~0.1 MPa, moisture less than 15 PPM, and the fluidized coefficient of powder coating 140 or so.%介绍了粉末涂料流动性的检测原理及判断指标,从粉末涂料树脂的选择、粉末颗粒形状与粒径、流化空气质量,喷涂环境湿度、涂料流化助剂等方面,探讨了影响粉末涂料流动性的因素,并提出相应的生产工艺控制参数与措施.生产实践证明,粉末流动性效果好的较佳工艺参数为:树脂分子量选择2 000~5000,玻璃化温度Tg50~65℃;颗粒形状球形,粒径分布20~80 μm;流化空气的压力0.01~0.1 MPa,而水在流化空气中的质量浓度(水的含量)小于15×10-6mg/L;粉末涂料的流化系数在140左右.

  19. Quantitative spray analysis of diesel fuel and its emulsions using digital image processing

    Directory of Open Access Journals (Sweden)

    Faik Ahmad Muneer El-Deen

    2015-01-01

    Full Text Available In the present work, an experimental investigation of spray atomization of different liquids has been carried out. An air-assist atomizer operating at low injection pressures valued (4 and 6 bar has been used to generate sprays of (diesel fuel, 5, 10, and 15% water-emulsified-diesel, respectively. A Photron-SA4 high speed camera has been used for spray imaging at 2000 fps. 20 time intervals (from 5 to 100 ms with 5 ms time difference are selected for analysis and comparison. Spray macroscopic characteristics (spray penetration, dispersion, cone angle, axial and dispersion velocities have been extracted by a proposed technique based on image processing using Matlab, where the maximum and minimum (horizontal and vertical boundaries of the spray are detected, from which the macroscopic spray characteristics are evaluated. The maximum error of this technique is (1.5% for diesel spray and a little bit higher for its emulsions.

  20. Design of a Microgravity Spray Cooling Experiment

    Science.gov (United States)

    Baysinger, Kerri M.; Yerkes, Kirk L.; Michalak, Travis E.; Harris, Richard J.; McQuillen, John

    2004-01-01

    An analytical and experimental study was conducted for the application of spray cooling in a microgravity and high-g environment. Experiments were carried out aboard the NASA KC-135 reduced gravity aircraft, which provided the microgravity and high-g environments. In reduced gravity, surface tension flow was observed around the spray nozzle, due to unconstrained liquid in the test chamber and flow reversal at the heat source. A transient analytical model was developed to predict the temperature and the spray heat transfer coefficient within the heated region. Comparison of the experimental transient temperature variation with analytical results showed good agreement for low heat input values. The transient analysis also verified that thermal equilibrium within the heated region could be reached during the 20-25s reduced gravity portion of the flight profile.

  1. Cold spray nozzle design

    Science.gov (United States)

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  2. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  3. Spray drying of fruit and vegetable juices--a review.

    Science.gov (United States)

    Verma, Anjali; Singh, Satya Vir

    2015-01-01

    The main cause of spray drying is to increase the shelf life and easy handling of juices. In the present paper, the studies carried out so far on spray drying of various fruits and vegetables are reported. The major fruit juices dried are mango, banana, orange, guava, bayberry, watermelon, pineapple, etc. However, study on vegetable juices is limited. In spray drying, the major optimized parameters are inlet air temperature, relative humidity of air, outlet air temperature, and atomizer speed that are given for a particular study. The juices in spray drying require addition of drying agents that include matlodextrin, liquid glucose, etc. The drying agents are added to increase the glass transition temperature. Different approaches for spray dryer design have also been discussed in the present work.

  4. Spray characterization during vibration-induced drop atomization

    Science.gov (United States)

    Vukasinovic, Bojan; Smith, Marc K.; Glezer, Ari

    2004-02-01

    Vibration-induced drop atomization is a process of rapid droplet ejection from a larger liquid drop. This occurs when a liquid drop resting on a thin diaphragm is vibrated under the appropriate forcing conditions using an attached piezoelectric actuator. The resulting spray of small droplets is characterized in this work using high-speed imaging and particle-tracking techniques. The results show that the average spatial and velocity distributions of the spray droplets are fairly axisymmetric during all stages of the atomization. The mean diameter of the droplets depends on the forcing frequency to the -2/3 power. The ejection velocity of the spray droplets depends on both the magnitude and the rate of change of the forcing amplitude. Thus, controlling the characteristics of the forcing signal may lead to strategies for controlling the spray process in specific applications.

  5. Thermal Arc Spray Overview

    Science.gov (United States)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  6. Evaluation of effervescent atomizer internal design on the spray unsteadiness using a phase/Doppler particle analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Meng; Duan, YuFeng; Zhang, TieNan [School of Energy and Environment, Southeast University, Sipailou 2, Nanjing 210096 (China)

    2010-09-15

    The purpose of this research was to investigate the dependence of effervescent spray unsteadiness on operational conditions and atomizer internal design by the ideal spray theory of Edwards and Marx. The convergent-divergent effervescent atomizer spraying water with air as atomizing medium in the ''outside-in'' gas injection was used in this study. Results demonstrated that droplet formation process at various air to liquid ratio (ALR) led to the spray unsteadiness and all droplet size classes exhibited unsteadiness behavior in spray. The spray unsteadiness reduced quickly at ALR of 3% and decreased moderately at ALR of other values as the axial distance increased. When the axial distance was 200 mm, the spray unsteadiness reduced dramatically with the increase in radial distance, but lower spray unsteadiness at the center of spray and higher spray unsteadiness at the edge of spray were shown as the axial distance increased. The spray unsteadiness at the center region of spray increased with the injection pressure. Low spray unsteadiness and good atomization performance can be obtained when the diameter of incline aeration holes increased at ALR of 10%. Although short mixing chamber with large discharge orifice diameter for convergent-divergent effervescent atomizer produced good atomization, the center region of spay showed high spray unsteadiness and maybe formed the droplet clustering. (author)

  7. LES/FMDF of High Speed Spray Combustion

    Science.gov (United States)

    Irannejad, Abolfazl; Jaberi, Farhad

    2013-11-01

    High speed evaporating and combusting sprays are computed with the hybrid two-phase large eddy simulation (LES)/filtered mass density function (FMDF) methodology. In this methodology, the resolved fluid velocity is obtained by solving the filtered form of the compressible Navier-Stokes equations with high-order finite difference schemes. The scalar (temperature and species mass fractions) field is obtained by solving the FMDF transport equation with a Lagrangian stochastic method. The spray is simulated with the Lagrangian droplets together with stochastic breakup and finite rate heat and mass transfer models. The liquid volume fraction is included in the LES/FMDF for denser spray regions. Simulations of high speed evaporating sprays with and without combustion for a range of gas and spray conditions indicate that the two-phase LES/FMDF results are consistent and compare well with the experimental results for global spray variables such as the spray penetration and flame lift-off lengths. The gas velocity and turbulence generated by the spray are found to be very significant in all simulated cases. A broad spectrum of droplet sizes is also found to be generated by the complex and coupled effects of the gas flow turbulence, droplet breakup, evaporation and combustion.

  8. 2001 spray program prospectus

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes weed control on Malheur National Wildlife Refuge in 2001. A total of 2,152 acres were sprayed. Pesticide application report records are...

  9. Zolmitriptan Nasal Spray

    Science.gov (United States)

    ... a copy of the manufacturer's information for the patient.To use the nasal spray, follow these steps: ... used to treat certain types of migraine headaches (hemiplegic or basilar) or other types of headaches (such ...

  10. Budesonide Nasal Spray

    Science.gov (United States)

    ... ingredients in budesonide nasal spray. Check the package label for a list of the ingredients.tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or ...

  11. Fluticasone Nasal Spray

    Science.gov (United States)

    ... ingredients in fluticasone nasal spray. Check the package label for a list of the ingredients.tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking, or ...

  12. Numerical investigation of the effects of fuel spray type on the interaction of fuel spray and hot porous medium

    Institute of Scientific and Technical Information of China (English)

    Zhiguo ZHAO; Maozhao XIE

    2008-01-01

    The interaction between two types of fuel spray and a hot porous medium is studied numerically by using an improved version of KIVA-3V code. The improved KIVA-3V code is incorporated with an impingement model, a heat transfer model and a linearized instability sheet atomization (LISA) model to model the hollow cone spray. An evaporating fuel spray impingement on a hot plane surface was simulated under conditions of experiments performed by Senda to validate the reasonability of the KIVA-3V code. The numerical results conform well with experimental data for spray radius in the liquid and the vapor phases. Computational results on the interaction of two types of the fuel spray and the hot porous medium show that the fuel spray can be split, which provides conditions for quick evaporation of fuel droplets and mixing of fuel vapor with air. The possibility of fuel droplets from hollow cone spray crossing the porous medium reduces compared with that from solid cone spray, with the same initial kinetic energy of fuel droplets in both injection types.

  13. Spray applicator for spraying coatings and other fluids in space

    Science.gov (United States)

    Kuminecz, J. F.; Lausten, M. F. (Inventor)

    1985-01-01

    A self contained spray application is developed for one handed operation in a zero gravity vacuum environment by a free flying astronaut not attached to any spacecraft. This spray applicator eliminates contamination of the operator by back spray. This applicator includes a rigid accumulator containment of a fluid within a flexible bladder the fluid being urged out of the accumulator under pressure through a spray gun. The spray gun includes a spring loaded lockable trigger which controls a valve. When in an open position, the fluid passes through the valve into the ambient environment in the form of a spray. A spray shield is provided which directs the flow of the spray from the applicator by trapping errant particles of spray yet allowing the passage of escaping gases through its material.

  14. Metal atomization spray nozzle

    Science.gov (United States)

    Huxford, Theodore J.

    1993-01-01

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

  15. Detailed investigation of a vaporising fuel spray. Part 1: Experimental investigation of time averaged spray

    Science.gov (United States)

    Yule, A. J.; Seng, C. A.; Boulderstone, R.; Ungut, A.; Felton, P. G.; Chigier, N. A.

    1980-01-01

    A laser tomographic light scattering technique provides rapid and accurate high resolution measurements of droplet sizes, concentrations, and vaporization. Measurements using a computer interfaced thermocouple are presented and it is found that the potential exists for separating gas and liquid temperature measurements and diagnosing local spray density by in situ analysis of the response characteristics of the thermocouple. The thermocouple technique provides a convenient means for measuring mean gas velocity in both hot and cold two phase flows. The experimental spray is axisymmetric and has carefully controlled initial and boundary conditions. The flow is designed to give relatively insignificant transfer of momentum and mass from spray to air flow. The effects of (1) size-dependent droplet dispersion by the turbulence, (2) the initial spatial segregation of droplet sizes during atomization, and (3) the interaction between droplets and coherent large eddies are diagnosed.

  16. Inhalational and dermal exposures during spray application of biocides.

    Science.gov (United States)

    Berger-Preiss, Edith; Boehncke, Andrea; Könnecker, Gustav; Mangelsdorf, Inge; Holthenrich, Dagmar; Koch, Wolfgang

    2005-01-01

    Data on inhalational and potential dermal exposures during spray application of liquid biocidal products were generated. On the one hand, model experiments with different spraying devices using fluorescent tracers were carried out to investigate the influence of parameters relevant to the exposure (e.g. spraying equipment, nozzle size, direction of application). On the other hand, measurements were performed at selected workplaces (during disinfection operations in food and feed areas; pest control operations for private, public and veterinary hygiene; wood protection and antifouling applications) after application of biocidal products such as Empire 20, Responsar SC, Omexan-forte, Actellic, Perma-forte; Fendona SC, Pyrethrum mist; CBM 8, Aldekol Des 03, TAD CID, Basileum, Basilit. The measurements taken in the model rooms demonstrated dependence of the inhalation exposure on the type of spraying device used, in the following order: "spraying with low pressure" < "airless spraying" < "fogging" indicating that the particle diameter of the released spray droplets is the most important parameter. In addition inhalation exposure was lowest when the spraying direction was downward. Also for the potential dermal exposure, the spraying direction was of particular importance: overhead spraying caused the highest contamination of body surfaces. The data of inhalational and potential dermal exposures gained through workplace measurements showed considerable variation. During spraying procedures with low-pressure equipments, dose rates of active substances inhaled by the operators ranged from 7 to 230 microg active substance (a.s.)/h. An increase in inhaled dose rates (6-33 mg a.s./h) was observed after use of high application volumes/time unit during wood protection applications indoors. Spraying in the veterinary sector using medium-pressure sprayers led to inhaled dose rates between 2 and 24mga.s./h. The highest inhaled dose rates were measured during fogging (114 mg a

  17. Transported PDF Modeling of Ethanol Spray in Hot-Diluted Coflow Flame

    NARCIS (Netherlands)

    Ma, L.; Naud, B.; Roekaerts, D.J.E.M.

    2015-01-01

    This paper presents a numerical modeling study of one ethanol spray flame from the Delft Spray-in-Hot-Coflow (DSHC) database, which has been used to study Moderate or Intense Low-oxygen Dilution (MILD) combustion of liquid fuels (Correia Rodrigues et al. Combust. Flame 162(3), 759–773, 2015). A “Lag

  18. Experimental studies on removal of carbon dioxide by aqueous ammonia fine spray

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Experimental studies on carbon dioxide capture in a spray scrubber were carried out.Fine spray of aqueous ammonia was used as CO2 absorbent.Effects of different operating and design parameters on CO2 removal efficiency including concentration of aqueous ammonia,liquid flow rate,total gas flow rate,initial temperature and concentration of carbon dioxide were investigated.

  19. Nasal spray flu vaccine (image)

    Science.gov (United States)

    The flu vaccine can also be administered as a nasal spray instead of the usual injection method. It can be ... the recombinant influenza vaccine (RIV). The nasal spray flu vaccine (live attenuated influenza vaccine or LAIV) should not ...

  20. JIT Spraying and Mitigations

    CERN Document Server

    Bania, Piotr

    2010-01-01

    With the discovery of new exploit techniques, novel protection mechanisms are needed as well. Mitigations like DEP (Data Execution Prevention) or ASLR (Address Space Layout Randomization) created a significantly more difficult environment for exploitation. Attackers, however, have recently researched new exploitation methods which are capable of bypassing the operating system’s memory mitigations. One of the newest and most popular exploitation techniques to bypass both of the aforementioned security protections is JIT memory spraying, introduced by Dion Blazakis. In this article we will present a short overview of the JIT spraying technique and also novel mitigation methods against this innovative class of attacks. An anti-JIT spraying library was created as part of our shellcode execution prevention system.

  1. Measurements and predictions for nonevaporating sprays in a quiescent environment

    Science.gov (United States)

    Solomon, A. S. P.; Shuen, J.-S.; Faeth, G. M.; Zhang, Q.-F.

    1983-01-01

    Yule et al. (1982) have conducted a study of vaporizing sprays with the aid of laser techniques. The present investigation has the objective to supplement the measurements performed by Yule et al., by considering the limiting case of a spray in a stagnant environment. Mean and fluctuating velocities of the continuous phase are measured by means of laser Doppler anemometry (LDA) techniques, while Fraunhofer diffraction and slide impaction methods are employed to determine drop sizes. Liquid fluxes in the spray are found by making use of an isokinetic sampling probe. The obtained data are used as a basis for the evaluation of three models of the process, including a locally homogeneous flow (LHF) model, a deterministic separated flow (DSF) model, and a stochastic separated flow (SSF) model. It is found that the LHF and DSF models do not provide very satisfactory predictions for the test sprays, while the SSF model does provide reasonably good predictions of the observed structure.

  2. Application of Constrained Linear MPC to a Spray Dryer

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik;

    2014-01-01

    In this paper we develop a linear model predictive control (MPC) algorithm for control of a two stage spray dryer. The states are estimated by a stationary Kalman filter. A non-linear first-principle engineering model is developed to simulate the spray drying process. The model is validated against...... experimental data and able to precisely predict the temperatures, the air humidity and the residual moisture in the dryer. The MPC controls these variables to the target and reject disturbances. Spray drying is a cost-effective method to evaporate water from liquid foods and produces a free flowing powder....... The main challenge of spray drying is to meet the residual moisture specification and prevent powder from sticking to the chamber walls. By simulation we compare the performance of the MPC against the conventional PID control strategy. During an industrially recorded disturbance scenario, the MPC increases...

  3. Planar velocity analysis of diesel spray shadow images

    CERN Document Server

    Sedarsky, David; Blaisot, J-B; Rozé, C

    2012-01-01

    The focus of this work is to demonstrate how spatially resolved image information from diesel fuel injection events can be obtained using a forward-scatter imaging geometry, and used to calculate the velocities of liquid structures on the periphery of the spray. In order to obtain accurate velocities directly from individual diesel spray structures, those features need to be spatially resolved in the measurement. The distributed structures measured in a direct shadowgraphy arrangement cannot be reliably analyzed for this kind of velocity information. However, by utilizing an intense collimated light source and adding imaging optics which modify the signal collection, spatially resolved optical information can be retrieved from spray edge regions within a chosen object plane. This work discusses a set of measurements where a diesel spray is illuminated in rapid succession by two ultrafast laser pulses generated by a mode-locked Ti-Sapphire oscillator seeding a matched pair of regenerative amplifiers. Light fro...

  4. Hollow-Cone Spray Modeling for Outwardly Opening Piezoelectric Injector

    KAUST Repository

    Sim, Jaeheon

    2016-01-04

    Linear instability sheet atomization (LISA) breakup model has been widely used for modeling hollow-cone spray. However, the model was originally developed for inwardlyopening pressure-swirl injectors by assuming toroidal ligament breakups. Therefore, LISA model is not suitable for simulating outwardly opening injectors having string-like structures at wide spray angles. Furthermore, the varying area and shape of the annular nozzle exit makes the modeling difficult. In this study, a new spray modeling was proposed for outwardly opening hollow-cone injector. The injection velocities are computed from the given mas flow rate and injection pressure regardless of ambiguous nozzle exit geometries. The modified Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) breakup model is used with adjusted initial Sauter mean diameter (SMD) for modeling breakup of string-like liquid film spray. Liquid spray injection was modeled using Lagrangian discrete parcel method within the framework of commercial CFD software CONVERGE, and the detailed model was implemented by user defined functions. It was found that the new model predicted the liquid penetration length and local SMD accurately for various fuels and chamber conditions.

  5. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, SHARPE MANUFACTURING TITANIUM T1-CG SPRAY GUN

    Science.gov (United States)

    Under EPA’s Environmental Technology Verification program, which provides objective and scientific third party analysis of new technology that can benefit the environment, the pollution prevention capabilities of a high transfer efficiency liquid spray gun was tested. This ...

  6. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, ANEST IWATA CORPORATION W400-LV SPRAY GUN

    Science.gov (United States)

    Under EPA’s Environmental Technology Verification program, which provides objective and scientific third party analysis of new technology that can benefit the environment, the pollution prevention capabilities of a high transfer efficiency liquid spray gun was tested. This ...

  7. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, ANEST IWATA CORPORATION W400-LV SPRAY GUN

    Science.gov (United States)

    Under EPA’s Environmental Technology Verification program, which provides objective and scientific third party analysis of new technology that can benefit the environment, the pollution prevention capabilities of a high transfer efficiency liquid spray gun was tested. This ...

  8. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, SHARPE MANUFACTURING TITANIUM T1-CG SPRAY GUN

    Science.gov (United States)

    Under EPA’s Environmental Technology Verification program, which provides objective and scientific third party analysis of new technology that can benefit the environment, the pollution prevention capabilities of a high transfer efficiency liquid spray gun was tested. This ...

  9. Functional and physicochemical properties of whole egg powder: effect of spray drying conditions

    OpenAIRE

    2010-01-01

    Pasteurized liquid whole egg was subjected to spray drying to determine the effect of spray drying conditions on moisture content, water activity, peroxide value, emulsion stability, gel texture, foaming stability and colour change of the powder product. Drying process was carried out in a pilot scale spray dryer (Mobile Minor Niro-Atomizer, Denmark). The inlet (165–195 °C) and outlet air temperatures (60–80 °C) and the atomization pressure (196–392 kPa) were investigated as spray drying proc...

  10. Spray Modeling for Outwardly-Opening Hollow-Cone Injector

    KAUST Repository

    Sim, Jaeheon

    2016-04-05

    The outwardly-opening piezoelectric injector is gaining popularity as a high efficient spray injector due to its precise control of the spray. However, few modeling studies have been reported on these promising injectors. Furthermore, traditional linear instability sheet atomization (LISA) model was originally developed for pressure swirl hollow-cone injectors with moderate spray angle and toroidal ligament breakups. Therefore, it is not appropriate for the outwardly-opening injectors having wide spray angles and string-like film structures. In this study, a new spray injection modeling was proposed for outwardly-opening hollow-cone injector. The injection velocities are computed from the given mass flow rate and injection pressure instead of ambiguous annular nozzle geometry. The modified Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) breakup model is used with adjusted initial Sauter mean diameter (SMD) for modeling breakup of string-like structure. Spray injection was modeled using a Lagrangian discrete parcel method within the framework of commercial CFD software CONVERGE, and the new model was implemented through the user-defined functions. A Siemens outwardly-opening hollow-cone spray injector was characterized and validated with existing experimental data at the injection pressure of 100 bar. It was found that the collision modeling becomes important in the current injector because of dense spray near nozzle. The injection distribution model showed insignificant effects on spray due to small initial droplets. It was demonstrated that the new model can predict the liquid penetration length and local SMD with improved accuracy for the injector under study.

  11. Encapsulation of shiitake (Lenthinus edodes) flavors by spray drying.

    Science.gov (United States)

    Shiga, Hirokazu; Yoshii, Hidefumi; Ohe, Hisashi; Yasuda, Masahumi; Furuta, Takeshi; Kuwahara, Hiroshige; Ohkawara, Masaaki; Linko, Pekka

    2004-01-01

    Powdery encapsulation of shiitake flavors, extracted from dried shiitake, was investigated by spray drying. Flavor retention increased with an increase in drying air temperature and solid content, and decreased with an increase in dextrose equivalents of maltodextrin. A heat-treatment of the extract liquid made the lenthionine concentration increase, but did not influence the concentrations of the other flavors. The formation of lenthionine with heat-treatment could be described by the consecutive unimolecular-type first order reaction. Lenthionine content in a spray-dried powder prepared with the heated extracted liquid significantly increased. alpha-Cyclodextrin was the most suitable encapsulant of alpha-, beta-, and gamma-cyclodextrins to prepare the spray-dried powder, including lenthionine. The flavor retentions were markedly increased by using of alpha-cyclodextrin and maltodextrin in combination as an encapsulant.

  12. Direct Biofluid Analysis Using Hydrophobic Paper Spray Mass Spectrometry.

    Science.gov (United States)

    Damon, Deidre E; Davis, Kathryn M; Moreira, Camila R; Capone, Patricia; Cruttenden, Riley; Badu-Tawiah, Abraham K

    2016-02-01

    Ambient electrostatic paper spray ionization from a hydrophobic paper occurs when a DC potential is applied to the dry paper triangle. Online liquid/liquid extraction of small organic compounds from a drop of biological fluid present on the dry hydrophobic paper is achieved with an organic spray solvent in under 1 min and utilizes in situ electrostatic-spray ionization for more efficient detection of extracted molecules. Direct analysis of small volumes of biofluids with no sample pretreatment is possible, which is applicable in point-of-care analyses. High sensitivity and quantitative accuracy was achieved for the direct analysis of illicit drugs in 4 μL of raw blood, serum, and whole urine. The study was extended to monitor the activity of alanine transaminase enzyme, a key biomarker for the detection of liver injury in patients (with HIV and tuberculosis) who typically take several medications at once.

  13. Calcitonin Salmon Nasal Spray

    Science.gov (United States)

    ... is important that you get enough calcium and vitamin D while you are using calcitonin salmon. Your doctor may prescribe supplements if your dietary ... examinations of the nose to make sure calcitonin salmon nasal spray is not ... such as vitamins, minerals, or other dietary supplements. You should bring ...

  14. Sequential cryogen spraying for heat flux control at the skin surface

    Science.gov (United States)

    Majaron, Boris; Aguilar, Guillermo; Basinger, Brooke; Randeberg, Lise L.; Svaasand, Lars O.; Lavernia, Enrique J.; Nelson, J. Stuart

    2001-05-01

    Heat transfer rate at the skin-air interface is of critical importance for the benefits of cryogen spray cooling in combination with laser therapy of shallow subsurface skin lesions, such as port-wine stain birthmarks. With some cryogen spray devices, a layer of liquid cryogen builds up on the skin surface during the spurt, which may impair heat transfer across the skin surface due to relatively low thermal conductivity and potentially higher temperature of the liquid cryogen layer as compared to the spray droplets. While the mass flux of cryogen delivery can be adjusted by varying the atomizing nozzle geometry, this may strongly affect other spray properties, such as lateral spread (cone), droplet size, velocity, and temperature distribution. We present here first experiments with sequential cryogen spraying, which may enable accurate mass flux control through variation of spray duty cycle, while minimally affecting other spray characteristics. The observed increase of cooling rate and efficiency at moderate duty cycle levels supports the above described hypothesis of isolating liquid layer, and demonstrates a novel approach to optimization of cryogen spray devices for individual laser dermatological applications.

  15. Discrete element modelling of fluidised bed spray granulation

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Weijers, G.G.C.; Boerefijn, R.; Kuipers, J.A.M.

    2003-01-01

    A novel discrete element spray granulation model capturing the key features of fluidised bed hydrodynamics, liquid¿solid contacting and agglomeration is presented. The model computes the motion of every individual particle and droplet in the system, considering the gas phase as a continuum. Microsca

  16. Discrete element modelling of fluidised bed spray granulation

    NARCIS (Netherlands)

    Goldschmidt, M.J.V.; Weijers, G.G.C.; Boerefijn, R.; Kuipers, J.A.M.

    2002-01-01

    A novel discrete element spray granulation model capturing the key features of fluidised bed hydrodynamics, liquid-solid contacting and agglomeration is presented. The model computes the motion of every individual particle and droplet in the system, considering the gas phase as a continuum. Micro sc

  17. Electro spraying of titania for nitrogen oxide abatement

    NARCIS (Netherlands)

    Ursem, W.N.J.; Marijnissen, J.C.; Roos, R.A.; Kelder, E.M.

    2010-01-01

    The invention provides a method for the production of a titania coating (80) on a surface (101) of an object (100) comprising electro spraying a titanium comprising liquid (15) to the surface (101) of the object (100) to provide a titanium comprising layer (85); and heating thetitanium comprising la

  18. Simulation of heat and mass transfer in spray drying

    NARCIS (Netherlands)

    Lijn, van der J.

    1976-01-01

    A survey is given of heat and mass transfer around droplets in spray dryers and the diffusional transport inside them. A calculational model is developed which includes variable diffusion coefficients in the drying liquid and swelling or shrinking of droplets. Calculations for droplets containing so

  19. Improved amine spray reagent for the detection of sugars

    NARCIS (Netherlands)

    Niemann, G.J.

    1979-01-01

    In the course of our investigations on naturally occurring flavonoid glycosides, the sugars obtained after acid hydrolysis were mainly analysed by gas-liquid chromatography and/or paper chromatography, using p-anisidine phosphate as the spray reagent. Often only very small amounts of the isolated co

  20. Spray and High-Pressure Flow Computations in the National Combustion Code (NCC) Improved

    Science.gov (United States)

    Raju, Manthena S.

    2002-01-01

    Sprays occur in a wide variety of industrial and power applications and in materials processing. A liquid spray is a two-phase flow with a gas as the continuous phase and a liquid as the dispersed phase in the form of droplets or ligaments. The interactions between the two phases--which are coupled through exchanges of mass, momentum, and energy--can occur in different ways at disparate time and length scales involving various thermal, mass, and fluid dynamic factors. An understanding of the flow, combustion, and thermal properties of a rapidly vaporizing spray requires careful modeling of the ratecontrolling processes associated with turbulent transport, mixing, chemical kinetics, evaporation, and spreading rates of the spray, among many other factors. With the aim of developing an efficient solution procedure for use in multidimensional combustor modeling, researchers at the NASA Glenn Research Center have advanced the state-of-the-art in spray computations in several important ways.

  1. Design and performance of a full-scale spray calciner for nonradioactive high-level-waste-vitrification studies

    Energy Technology Data Exchange (ETDEWEB)

    Miller, F.A.

    1981-06-01

    In the spray calcination process, liquid waste is spray-dried in a heated-wall spray dryer (termed a spray calciner), and then it may be combined in solid form with a glass-forming frit. This mixture is then melted in a continuous ceramic melter or in an in-can melter. Several sizes of spray calciners have been tested at PNL- laboratory scale, pilot scale and full scale. Summarized here is the experience gained during the operation of PNL's full-scale spray calciner, which has solidified approx. 38,000 L of simulated acid wastes and approx. 352,000 L of simulated neutralized wastes in 1830 h of processing time. Operating principles, operating experience, design aspects, and system descriptions of a full-scale spray calciner are discussed. Individual test run summaries are given in Appendix A. Appendices B and C are studies made by Bechtel Inc., under contract by PNL. These studies concern, respectively, feed systems for the spray calciner process and a spray calciner vibration analysis. Appendix D is a detailed structural analysis made at PNL of the spray calciner. These appendices are included in the report to provide a complete description of the spray calciner and to include all major studies made concerning PNL's full-scale spray calciner.

  2. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

  3. Sea Spray Aerosols

    DEFF Research Database (Denmark)

    Butcher, Andrew Charles

    emissions produced directly from bubble bursting as the result of air entrainment from breaking waves and particles generated from secondary emissions of volatile organic compounds. In the first paper, we study the chemical properties of particles produced from several sea water proxies with the use...... of a cloud condensation nuclei ounter. Proxy solutions with high inorganic salt concentrations and some organics produce sea spray aerosol particles with little change in cloud condensation activity relative to pure salts. Comparison is made between a frit based method for bubble production and a plunging...... a relationship between plunging jet particle ux, oceanic particle ux, and energy dissipation rate in both systems. Previous sea spray aerosol studies dissipate an order of magnitude more energy for the same particle ux production as the open ocean. A scaling factor related to the energy expended in air...

  4. The effect of liquid film on liquid droplet impingement erosion

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, Nobuyuki, E-mail: fujisawa@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Yamagata, Takayuki, E-mail: yamagata@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Saito, Kengo; Hayashi, Kanto [Graduate School of Science and Technology, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan)

    2013-12-15

    Highlights: • Liquid droplet impingement erosion is studied experimentally using high-speed conical spray. • Erosion rate is increased with decreasing the liquid film thickness. • Erosion model is proposed considering the influence of liquid film thickness. -- Abstract: In the present paper, the pipe-wall thinning due to liquid droplet impingement erosion is studied experimentally by using a high-speed conical spray under the influences of liquid film on the target specimen. The size of the droplets considered is an order of tens of micrometers in diameter, which is the same order as those expected in the pipeline of nuclear/fossil power plants. In order to evaluate the erosion rate by the liquid droplet impingement under the influence of liquid film, the experiments are conducted by various combinations of the specimen diameters and the standoff distances of the spray from the nozzle. The experimental results show that the erosion depth increases linearly with the local flow volume, indicating the presence of terminal stage of erosion. The present results indicate that the erosion rate increases with decreasing the specimen diameter and increases slightly with increasing the standoff distance. This result combined with the theoretical consideration of the liquid film on the specimen leads to the conclusion that the erosion rate increases with decreasing the liquid film thickness, which supports the numerical result of liquid droplet impingement erosion in literature. Then, the erosion model for predicting the erosion rate by the liquid droplet impingement is proposed considering the influence of the liquid film.

  5. Plasma Spray Forming

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In the course of plasma spray, the plasma jet is comprehensively functioned by such effects as thermal pinch, magnetic pinch and mechanical compression and the flow is jetting at a high speed, the energy is concentrated and its center temperature is so high as to reach upwards of 15 000 ℃ which is capable of melting various kinds of materials inclusive of ceramic, it has a broad applied prospects in the fields of automobile, electronics, telecommunications, medical treatment, air navigation & space navigati...

  6. Combustion Characteristics of Sprays

    Science.gov (United States)

    1989-08-01

    regarded by implication or otherwise, or in any way licensing the holder or any other person or corporation, or conveying any rights or permission to...00 _’N 1. TI TLE inctuat Security CZaaafication5 Combustion Characteristics of Sprays 12. PERSONAL AUTHOR(S) Sohrab, Siavash H. 13& TYPE OF REPORT...to ?!HF of rich butane/air 3unsen flames. .lso, the rotacion speed and :he oerodic temDeracure fluc:uations of rotacfng ?HF are examined. :’!naily

  7. Vacuum plasma spray coating

    Science.gov (United States)

    Holmes, Richard R.; Mckechnie, Timothy N.

    1989-01-01

    Currently, protective plasma spray coatings are applied to space shuttle main engine turbine blades of high-performance nickel alloys by an air plasma spray process. Originally, a ceramic coating of yttria-stabilized zirconia (ZrO2.12Y2O3) was applied for thermal protection, but was removed because of severe spalling. In vacuum plasma spray coating, plasma coatings of nickel-chromium-aluminum-yttrium (NiCrAlY) are applied in a reduced atmosphere of argon/helium. These enhanced coatings showed no spalling after 40 MSFC burner rig thermal shock cycles between 927 C (1700 F) and -253 C (-423 F), while current coatings spalled during 5 to 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2.8Y2O3 to the turbine blades of first-stage high-pressure fuel turbopumps utilizing the enhanced NiCrAlY bond-coating process. NiCrAlY bond coating is applied first, with ZrO2.8Y2O3 added sequentially in increasing amounts until a thermal barrier coating is obtained. The enchanced thermal barrier coating has successfully passed 40 burner rig thermal shock cycles.

  8. Spray boom for selectively spraying a herbicidal composition onto dicots

    DEFF Research Database (Denmark)

    2012-01-01

    There is provided a method and spray boom for discriminating cereal crop (monocot) and weeds (dicots). The spray boom includes means for digitally recording an image of a selected area to be treated by a nozzle on the spray boom, whereby a plant material is identified based on a segmentation...... procedure; and means for detecting the edges and estimating the angles of the edges of the leaves so as to discriminate between dicots and monocots; and means for activating one or more of the spray nozzles in response to detected dicots so as to selectively apply the herbicidal composition onto the sensed...... area containing the dicots....

  9. Developments in Spray Modeling in Diesel and Direct-Injection Gasoline Engines Progrès de la modélisation des sprays dans les moteurs Diesel et à essence

    OpenAIRE

    Kong S. C.; Senecal P. K.; Reitz R. D.

    2006-01-01

    In direct-injection engines, the fuel spray characteristics influence the combustion efficiency and exhaust emissions. The performance of available spray models for predicting liquid and vapor fuel distributions, and their influence on combustion is reviewed for both diesel and gasoline direct injection engines. A phenomenological nozzle flow model is described for simulating the effects of diesel injector nozzle internal geometry on the fuel injection and spray processes. The flow model prov...

  10. Fundamental studies of spray combustion

    Energy Technology Data Exchange (ETDEWEB)

    Li, S.C.; Libby, P.A.; Williams, F.A. [Univ. of California, San Diego, CA (United States)

    1997-12-31

    Our research on spray combustion involves both experiment and theory and addresses the characteristics of individual droplets and of sprays in a variety of flows: laminar and turbulent, opposed and impinging. Currently our focus concerns water and fuel sprays in two stage laminar flames, i.e., flames arising, for example from a stream of fuel and oxidizer flowing opposite to an air stream carrying a water spray. Our interest in these flames is motivated by the goals of reducing pollutant emissions and extending the range of stable spray combustion. There remains considerable research to be carried out in order to achieve these goals. Thus far our research on the characteristics of sprays in turbulent flows has been limited to nonreacting jets impinging on a plate but this work will be extended to opposed flows with and without a flame. In the following we discuss details of these studies and our plans for future work.

  11. Study on condensation of biomass pyrolysis gas by spray bio-oil droplets

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Kun; Cheng, Wen-Long [University of Science and Technology of China (China)], email: wlcheng@ustc.edu.cn; Chen, Jing [Anhui Electric Power Design Institute (China); Shi, Wen-Jing [Anhui Heli Co., Ltd (China)

    2011-07-01

    This is a study of bio-oil generated by fast pyrolysis; a biomass feedstock is heated to pyrolyze at a rapid rate, the gas pyrolyzed is then condensed rapidly. The interesting result is a potential alternative fuel oil. An analysis was made of the effects of the initial pyrolysis gas temperatures, the initial bio-oil droplets temperatures and diameters, and the flow ratio of the gas and the liquid droplets on the heat and mass transfer between the gas and the liquid droplets. A few criterion equations were achieved with respect to the spray condenser. This paper established the gas-liquid phase equilibrium of an aqueous multi-composition system and the spray condensation model coupling heat and mass transfer. Model calculation and analysis showed that: spray condensation can effectively cool the high-temperature pyrolysis gas quickly; with gas liquid flowing, mass transfer rate reduces; and the relationship of gas and liquid flow ratio can achieve good accuracy.

  12. Balanced Rotating Spray Tank and Pipe Cleaning and Cleanliness Verification System

    Science.gov (United States)

    Caimi, Raoul E. B. (Inventor); Thaxton, Eric A. (Inventor)

    1998-01-01

    A system for cleaning and verifying the cleanliness of the interior surfaces of hollow items, such as small bottles, tanks, pipes and tubes, employs a rotating spray head for supplying a gas-liquid cleaning mixture to the item's surface at a supersonic velocity. The spray head incorporates a plurality of nozzles having diverging cross sections so that the incoming gas-liquid mixture is first converged within the spray head and then diverged through the nozzles, thereby accelerating the mixture to a supersonic velocity. In the preferred embodiment, three nozzles are employed; one forwardly facing nozzle at the end of the spray head and two oppositely facing angled nozzles exiting on opposite sides of the spray head which balance each other, and therefore impart no net side load on the spray head. A drive mechanism is provided to rotate the spray head and at the same time move the head back and forth within the item to be cleaned. The drive mechanism acts on a long metal tube to which the spray head is fixed, and thus no moving parts are exposed to the interior surfaces of the items to be cleaned, thereby reducing the risk of contamination.

  13. Study of ethanol and gasoline fuel sprays using mie-scatter and schlieren imaging

    Science.gov (United States)

    Bouchard, Lauren; Bittle, Joshua; Puzinauskas, Paul

    2016-11-01

    Many cars today are capable of running on both gasoline and ethanol, however it is not clear how well optimized the engines are for the multiple fuels. This experiment looks specifically at the fuel spray in a direct injection system. The length and angle of direct injection sprays were characterized and a comparison between ethanol and gasoline sprays was made. Fuels were tested using a modified diesel injector in a test chamber at variable ambient pressures and temperatures in order to simulate both high and low load combustion chamber conditions. Rainbow schlieren and mie-scatter imaging were both used to investigate the liquid and vapor portions of the sprays. The sprays behaved as expected with temperature and pressure changes. There was no noticeable fuel effect on the liquid portion of the spray (mie-scatter), though the gasoline vapor spray angles were wider than ethanol spray angles (possible a result of the distillation curves of the two fuels). Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

  14. Plasma spraying system with distributed controlling

    Institute of Scientific and Technical Information of China (English)

    李春旭; 陈克选; 张成

    2003-01-01

    A distributed control system is designed for plasma spraying equipment and the configurations of system software and hardware is discussed. Through founding an expert database, the spraying process parameters are worked out and the initialization and control of spraying process are realized. The plasma spraying system with this control configuration can simplify the spraying operation, improve automation level of spray process, and approach the experience criterion as soon as possible.

  15. Characteristics of droplet motion in effervescent sprays

    Directory of Open Access Journals (Sweden)

    Jedelský Jan

    2014-03-01

    Full Text Available Time resolved droplet size and velocity measurement was made using Phase-Doppler anemometry in an effervescent spray at GLR of 6 % and operation pressure drops 21 – 52 kPa. The spray shows a size dependent variation of mean as well as fluctuating axial and radial velocities of droplets similarly for all operation regimes. Particles under 13 μm follow the gas flow, axially decelerated due to gas expansion. Velocity of medium sized particles is positively size correlated and larger particles keep high velocity, given them during discharge. Fluctuating radial velocity of small particles is larger than that of large particles while fluctuating axial velocity increases with size. Small particles thus reach a ratio of radial to axial velocity fluctuations ~ 0.6 but large particles only ~ 0.1, which indicates large transverse dispersion of small particles. Overall fluctuating velocity ratios smaller than 0.5 document an anisotropic character of the liquid mass fluctuations. Power spectral density (PSD of axial velocity fluctuations of large droplets is uniform up to 1 kHz, while PSD of smaller particles drops down with frequency for frequencies > 100 Hz. Large particles thus preserve the fluctuations imposed during discharge while the gas turbulence drops with frequency. Turbulence intensity reaches 14 to 21 % depending on pressure. Such high-turbulence character of the flow probably results from a heterogeneous gas–liquid mixture at the discharge.

  16. Microplasma sprayed hydroxyapatite coatings

    CERN Document Server

    Dey, Arjun

    2015-01-01

    ""This unique book on development of microplasma sprayed HAp coating has been organized in a very compact yet comprehensive manner. This book also highlights the horizons of future research that invites the attention of global community, particularly those in bio-medical materials and bio-medical engineering field. This book will surely act as a very useful reference material for both graduate/post-graduate students and researchers in the field of biomedical, orthopedic and manufacturing engineering and research. I truly believ that this is the first ever effort which covers almost all the

  17. Parameters of electrostatic spraying and its influence on the application efficiency

    Directory of Open Access Journals (Sweden)

    Robson Shigueaki Sasaki

    2013-08-01

    Full Text Available When the electrostatic spraying is used correctly, it provides advantages over conventional systems, however many factors can affect the system efficiency. Therefore, the objective of this study was to evaluate the charge/mass ratio (Q/M at different spraying distances (0, 1, 2, 3, 4 and 5 m, and the liquid deposition efficiency on the target. Evaluating the Q/M ratio the Faraday cage method was used and to evaluate the liquid deposition efficiency the artificial targets were positioned longitudinally and transversely to the spray jet. It was found that the spraying distance affects the Q/M ratio, consequently, the liquid deposition efficiency. For the closest distance to the target the Q/M ratio was 4.11 mC kg-1, and at distances of 1, 2, 3, 4 and 5 m, the ratio decreased to 1.38, 0.64, 0.31, 0.17 and 0.005 mC kg-1, respectively. For the liquid deposition, the electrostatic system was affected by the target orientation and spraying distance. The target transversely to the jet of liquid did not improve the liquid deposition, but longitudinally increased the deposition up to 3 meters of distance.

  18. Spray algorithm without interface construction

    Science.gov (United States)

    Al-Kadhem Majhool, Ahmed Abed; Watkins, A. P.

    2012-05-01

    This research is aimed to create a new and robust family of convective schemes to capture the interface between the dispersed and the carrier phases in a spray without the need to build up the interface boundary. The selection of the Weighted Average Flux (WAF) scheme is due to this scheme being designed to deal with random flux scheme which is second-order accurate in space and time. The convective flux in each cell face utilizes the WAF scheme blended with Switching Technique for Advection and Capturing of Surfaces (STACS) scheme for high resolution flux limiters. In the next step, the high resolution scheme is blended with the WAF scheme to provide the sharpness and boundedness of the interface by using switching strategy. In this work, the Eulerian-Eulerian framework of non-reactive turbulent spray is set in terms of theoretical proposed methodology namely spray moments of drop size distribution, presented by Beck and Watkins [1]. The computational spray model avoids the need to segregate the local droplet number distribution into parcels of identical droplets. The proposed scheme is tested on capturing the spray edges in modelling hollow cone sprays without need to reconstruct two-phase interface. A test is made on simple comparison between TVD scheme and WAF scheme using the same flux limiter on convective flow hollow cone spray. Results show the WAF scheme gives a better prediction than TVD scheme. The only way to check the accuracy of the presented models is by evaluating the spray sheet thickness.

  19. Plasma Spraying of Copper by Hybrid Water-Gas DC Arc Plasma Torch

    Science.gov (United States)

    Kavka, T.; Matějíček, J.; Ctibor, P.; Mašláni, A.; Hrabovský, M.

    2011-06-01

    Water-stabilized DC arc plasma torches offer a good alternative to common plasma sources used for plasma spraying applications. Unique properties of the generated plasma are determined by a specific plasma torch construction. This article is focused on a study of the plasma spraying process performed by a hybrid torch WSP500®-H, which combines two principles of arc stabilization—water vortex and gas flow. Spraying tests with copper powder have been carried out in a wide range of plasma torch parameters. First, analyses of particle in-flight behavior for various spraying conditions were done. After, particles were collected in liquid nitrogen, which enabled analyses of the particle in-flight oxidation. A series of spraying tests were carried out and coatings were analyzed for their microstructure, porosity, oxide content, mechanical, and thermal properties.

  20. Extinguishment of enclosed gas fires with water sprays

    Science.gov (United States)

    Wighus, R.

    1993-02-01

    Water sprays are widely used for fire fighting in industrial areas, and they are used for fire protection in the process industry and at offshore oil- and gas-production platforms. No real quantification of the effect of water sprays as a fire fighting medium exists. The water delivery is specified through standards and regulations which are based on industrial experience. In process areas, water spray is often used in deluge systems, intended to control the fire until the leakage of fuel has been shut down. For this purpose, there is a need for quantification of the ability a certain spray system has to remove heat from the fire and to reduce the fire load to the construction and process equipment. SINTEF NBL has studied extinguishment and control of enclosed hydrocarbon fires by means of water sprays. A scale model of a module of an offshore platform is used in studies of enclosed liquid hydrocarbon fire development. The model is instrumented to measure heat transfer, fire development, and production of soot and gases from combustion.

  1. Modelling of fuel spray and combustion in diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Huttunen, M.T.; Kaario, O.T. [VTT Energy, Espoo (Finland)

    1997-12-31

    Fuel spray and air motion characteristics and combustion in direct injection (DI) diesel engines was studied using computational models of the commercial CFD-code FIRE. Physical subprocesses modelled included Lagrangian spray droplet movement and behaviour (atomisation, evaporation and interaction of spray droplets) and combustion of evaporated liquid spray in the gas phase. Fuel vapour combustion rate was described by the model of Magnussen and Hjertager. The standard k,{epsilon}-model was used for turbulence. In order to be able to predict combustion accurately, the fuel spray penetration should be predicted with reasonable accuracy. In this study, the standard drag coefficient had to be reduced in order to match the computed penetration to the measured one. In addition, the constants in the submodel describing droplet breakup also needed to be adjusted for closer agreement with the measurements. The characteristic time scale of fuel consumption rate k/C{sub R} {epsilon} strongly influenced the heat release and in-cylinder pressure. With a value around 2.0 to 5.0 for C{sub R}, the computed in-cylinder pressure during the compression stroke agreed quite well with the measurements. On the other hand, the in-cylinder pressure was underpredicted during the expansion stroke. This is partly due to the fact that hydrocarbon fuel combustion was modelled as a one-step reaction reading to CO{sub 2} and H{sub 2}O and inadequate description of the mixing of reactants and combustion products. (author) 16 refs.

  2. Spray dispensing of antiseptics is effective for hand disinfection.

    Science.gov (United States)

    Meurman, J H; Pentti, P; Suhonen, J; Koskela, M

    1989-12-01

    The effectiveness of three hand antiseptics administered using a spray dispenser (Nebucid 840) was studied together with that of conventional hand disinfection. The tests were carried out by a group of 20 dental students. To obtain baseline samples, the subjects washed their hands with unmedicated Sterisol liquid soap under running water for 30s and dried them on sterile-packed paper towels. Microbiologic samples were taken from fingerprints pressed gently onto blood agar plates, which were then incubated aerobically and analyzed. The hand disinfection efficacy of 3 ml Isosept solution rubbed onto the hands for 30 s, followed by air drying for 60 s, was studied as a conventional control method. Dermocol, HD 410, and Hibisol antiseptics were sprayed onto the subjects' hands for 3 s using the automatic dispenser, after which the hands were gently rubbed for 30 s and air-dried for 60 s, before fingerprint contact sampling. All the tests were performed three times, with a minimum of 3 days between the series. The results showed Hibisol applied with the spray dispenser to be significantly more effective in reducing bacterial growth than the other methods. No growth was observed on 51 plates out of 60, while bacterial growth was observed in 29 cases out of 60 in the Isosept series. In most cases the spray-dispensed antiseptics proved to be more efficient than the conventional hand antiseptic. All the antiseptics were significantly more effective than the liquid soap.

  3. Arc-Plasma Wire Spraying: An Optical Study of Process Phenomenology

    Science.gov (United States)

    Gulyaev, I. P.; Dolmatov, A. V.; Kharlamov, M. Yu.; Gulyaev, P. Yu.; Jordan, V. I.; Krivtsun, I. V.; Korzhyk, V. M.; Demyanov, O. I.

    2015-12-01

    In the present paper, we report on the results of an experimental study of heat- and mass-transfer processes in a Plazer 30-PL-W plasma-jet facility used for arc-plasma wire spraying. Using an original optical diagnostic system, we have studied melting behavior of the metal wire, break up and atomization of liquid metal. For the first time, experimental data on the in-flight velocity and temperature of spray particles in arc-plasma wire spraying were obtained. In spite of moderate particle velocities (about 50 m/s), the obtained steel coatings proved to have a low porosity of 1.5%. While studying the spraying process of tungsten wire, we observed the occurrence of anomalous high-velocity (over 4000 m/s) outbursts ejected from the surface of liquid metal droplets. The nature of such outbursts calls for further study.

  4. Thermal spray forming of refractory sample ampoule cartridges for single crystal growth space furnaces

    Science.gov (United States)

    Zimmerman, Frank; Poorman, Richard; Holmes, Richard; Mckechnie, Timothy; Krotz, Phil; Liaw, Yoon

    1993-01-01

    A thermal spray process is being used to build up refractory metals and ceramics into a containment cartridge for high temperature, single crystal semiconductor growth experiments. This process uses high energy plasma inside a low pressure (100-200 torr) inert environment to apply layers of material onto a removable mandrel. A variety of materials are being characterized and evaluated against a demanding set of requirements, including high service temperature (1700 C), oxidation resistance, and resistance to liquid metal attack. Techniques to spray form refractory metals (tungsten, molybdenum, niobium, tantalum) and ceramics (alumina, boron nitride) are being developed in the Plasma Spray Cell at Marshall Space Flight Center. These plasma spray formed materials have been evaluated for mechanical properties, density, microstructure, and resistance to liquid metal attack. Forming techniques and the resultant mechanical and metallurgical properties are presented.

  5. Indoor spray measurement of spray drift potential using a spray drift test bench : effect of drift-reducing nozzle types, spray boom height, nozzle spacing and forward speed

    NARCIS (Netherlands)

    Moreno Ruiz, J.R.

    2014-01-01

    In a series of indoor experiments spray drift potential was assessed when spraying over a spray drift testbench with two different driving speeds, 2m/s and 4m/s, two different spray boom heights, 30 cm and 50 cm, and two different nozzle spacing, 25 cm and 50 cm, for six different nozzle types. The

  6. Study on Electric field assisted low frequency (20 kHz) ultrasonic spray

    Science.gov (United States)

    Chae, Ilkyeong; Seong, Baekhoon; Marten, Darmawan; Byun, Doyoung

    2015-11-01

    Ultrasonic spray is one of the fabulous techniques to discharge small size of droplets because it utilizes ultrasonic vibration on nozzle. However, spray patterns and size of ejected droplet is hardly controlled in conventional ultrasonic spray method. Therefore, here we present electric field assisted ultrasonic spray, which combined conventional technique with electric field in order to control spray pattern and droplet size precisely. Six kinds of various liquid (D.I water, Ethanol, Acetone, Iso-propanol, Toluene, Hexane) with various dielectric constants were used to investigate the mechanism of this method. Also, PIV (Particle Image Velocimetry) was used and various variables were obtained including spray angle, amplitude of liquid vibration, current, and size distribution of ejected droplets. Our electric field assisted ultrasonic spray show that the standard deviation of atomized droplet was decreased up to 39.6%, and it shows the infinite possibility to be utilized in various applications which require precise control of high transfer efficiency. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2014-023284).

  7. Spray Drying of High Sugar Content Foods: Improving of Product Yield and Powder Properties

    OpenAIRE

    Mehmet Koç; Figen Kaymak-Ertekin

    2016-01-01

    Spray drying is the most preferred drying method to produce powdered food in the food industry and it is also widely used to convert sugar-rich liquid foods to a powder form. During and/or after spray drying process of sugar-rich products, undesirable situation was appeared such as stickiness, high moisture affinity (hygroscopicity) and low solubility due to low molecular weight monosaccharides that found naturally in the structure. The basis of these problems was formed by low glass transiti...

  8. Injector Nozzle Flow Model and Its Effects on the Calculations of High Pressure Sprays

    Institute of Scientific and Technical Information of China (English)

    WEI Ming-rui; LIU Yong-chang; WEN Hua; ZHANG Yue-heng

    2004-01-01

    This paper discusses the flowing process inside a nozzle, especially the formation mechanism of cavitations within the nozzle and puts forward a nozzle flow model, which takes account of the injection conditions and nozzle geometry. By the model being implemented to the KIVA codes, the spray characteristics (e.g., spray penetration and cone angle) of diesel and dimethyl ether (DME) are simulated. The comparisons between the computational and experimental results are performed, which show that the liquid spray characteristics could be more truly demonstrated by considering the existence of the cavitations.

  9. Fluidized bed spray granulation: analysis of heat and mass transfers and dynamic particle populations

    Directory of Open Access Journals (Sweden)

    S. Heinrich

    2005-06-01

    Full Text Available A model was developed taking into consideration the heat and mass transfer processes in liquid-sprayed fluidized beds. Such fluidized beds (FB are used for granulation, coating and agglomeration. Conclusions are drawn on the relevance of particle dispersion, spraying and drying to temperature and concentrations distributions. In extension, the model was coupled with a population balance model to describe the particle size distribution and the seeds formation for continuous external FBSG (fluidized bed spray granulation with non-classifying product discharge and a screening and milling unit in the seeds recycle. The effects of seeds formation on the stability of the process is discussed.

  10. Developing a dispersant spraying capability

    Energy Technology Data Exchange (ETDEWEB)

    Gill, S.D.

    1979-01-01

    In developing a national dispersant spraying capability, the Canadian Coast Guard (CCG) has undertaken a modification program to enable the conventional offshore spraying gear to be mounted on almost any vessel of convenience. Smaller, more versatile inshore spraying vessels and pumps have been designed and built. With the popularization of concentrated dispersants, the inshore pumping equipment can be used aboard hovercraft for special application situations. A program of acquiring mobile dispersant storage tanks has been undertaken with auxiliary equipment that will facilitate the shipment of dispersants in bulk by air freight. Work also has commenced on extending the dispersant application program to include the CCG fleet of helicopters.

  11. Ultrasonic Plasma Spray--A New Plasma Spray Process

    Institute of Scientific and Technical Information of China (English)

    LU Zhi-qing; ZHANG Hua-tang; WEN Xiong-wei; LI Lu-ming

    2004-01-01

    The method of arc- ultrasonic is introduced into plasma spray process. The process of spray ZrO2-NiCoCr AlY thermal barrier coatings (TBCs) using air plasma spray (APS) process is studied. A exciting source which can be adjusted from audio frequency to several hundred thousand Hertz is designed successfully. The ultrasonic exciting source is coupled with conventional DC spraying power supply. A few ultrasonic frequencies are selected in the testing. Several parts of the coatings with the coupling arc- ultrasonic are compared with the coatings without it. The results show: with 50 kHz and 80 kHz ultrasound, the coating qualities are improved, whereas 30 kHz has an opposite effect.

  12. A Review on Atomization and Sprays of Biofuels for IC Engine Applications

    Directory of Open Access Journals (Sweden)

    Prasad Boggavarapu

    2013-06-01

    Full Text Available Ever increasing energy requirements, environmental concerns and energy security needs are strongly influencing engine researchers to consider renewable biofuels as alternatives to fossil fuels. Spray process being important in IC engine combustion, existing literature on various biofuel sprays is reviewed and summarized. Both experimental and computational research findings are reviewed in a detailed manner for compression ignition (CI engine sprays and briefly for spark ignition (SI engine sprays. The physics of basic atomization process of sprays from various injectors is included to highlight the most recent research findings followed by discussion highlighting the effect of physico-chemical properties on spray atomization for both biofuels and fossil fuels. Biodiesel sprays are found to penetrate faster and have narrow spray plume angle and larger droplet sizes compared to diesel. Results of analytical and computational models are shown to be useful in shedding light on the actual process of atomization. However, further studies on understanding primary atomization and the effect of fuel properties on primary atomization are required. As far as secondary atomization is concerned, changes in regimes are observed to occur at higher air-jet velocities for biodiesel compared to those of diesel. Evaporating sprays revealed that the liquid length is longer for biodiesel. Pure plant oil sprays with potential use in CI engines may require alternative injector technology due to slower breakup as compared to diesel. Application of ethanol to gasoline engines may be feasible without any modifications to port fuel injection (PFI engines. More studies are required on the application of alternative fuels to high pressure sprays used in Gasoline Direct Injection (GDI engines.

  13. Population balance modelling and multi-stage optimal control of a pulsed spray fluidized bed granulation.

    Science.gov (United States)

    Liu, Huolong; Li, Mingzhong

    2014-07-01

    In this work, one-dimensional population balance models (PBMs) have been developed to model a pulsed top-spray fluidized bed granulation. The developed PBMs have linked the key binder solution spray operating factors of the binder spray rate, atomizing air pressure and pulsed frequency of spray with the granule properties to predict granule growth behaviour in the pulsed spray fluidized bed granulation process at different operating conditions with accuracy. A multi-stage open optimal control strategy based on the developed PBMs was proposed to reduce the model mismatch, in which through adjusting the trajectory of the evolution of the granule size distribution at predefined sample intervals, to determine the optimal operating variables related to the binder spray including the spray rate of binding liquid, atomizing air pressure and pulsed frequency of spray. The effectiveness of the proposed modelling and multi-stage open optimal control strategies has been validated by experimental and simulation tests. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Ground experimental investigations into an ejected spray cooling system for space closed-loop application

    Directory of Open Access Journals (Sweden)

    Zhang Hongsheng

    2016-06-01

    Full Text Available Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor–liquid mixture from the heat surface and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space environments. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and experimental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 °C and 78.2 °C under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11.22 L/h to 15.76 L/h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

  15. Ground experimental investigations into an ejected spray cooling system for space closed-loop application

    Institute of Scientific and Technical Information of China (English)

    Zhang Hongsheng; Li Yunze; Wang Shengnan; Liu Yang; Zhong Mingliang

    2016-01-01

    Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor–liquid mixture from the heat sur-face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space environments. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper-imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ?C and 78.2 ?C under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11.22 L/h to 15.76 L/h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed;results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

  16. Clay as a matrix former for spray drying of drug nanosuspensions.

    Science.gov (United States)

    Dong, Yuancai; Ng, Wai Kiong; Hu, Jun; Shen, Shoucang; Tan, Reginald B H

    2014-04-25

    Utilization of sugars (e.g. lactose, sucrose) as matrix formers for spray drying of drug nanosuspensions is associated with two drawbacks: (1) sugars are incapable of preventing agglomeration of drug nanoparticles (NPs) in the suspension state; and (2) the spray-dried sugars are usually amorphous and hygroscopic. This work aimed to apply a clay, montmorillonite (MMT) as an alternative matrix former for spray drying of drug nanosuspensions with fenofibrate (feno) as a model compound. Drug nanosuspensions were synthesized by liquid antisolvent precipitation with different amount of MMT followed by spray drying. It is found that MMT is able to reduce the agglomeration of drug nanoparticles in the suspension state, as observed from the gradual alleviation of the clogging with the increased clay during the spray drying. The spray-dried feno NPs/MMT powders exhibited a much lower moisture sorption than spray-dried feno NPs/lactose powders as evidenced by the dynamic vapor sorption (DVS) analysis. The dissolution within 5 min for the spray-dried feno NPs/MMT powders at drug:MMT weight ratio of 1:3 was 81.4 ± 1.8% and the total dissolution within 60 min was 93.4 ± 0.9%. Our results demonstrate that MMT is a useful matrix former for preservation of the high dissolution rate of nanosized drug particles after drying.

  17. Effect of spray nozzle design on fish oil-whey protein microcapsule properties.

    Science.gov (United States)

    Legako, Jerrad; Dunford, Nurhan Turgut

    2010-08-01

    Microencapsulation improves oxidative stability and shelf life of fish oil. Spray and freeze drying are widely used to produce microcapsules. Newer spray-nozzles utilize multiple fluid channels allowing for mixing of wall and core materials at the point of atomization. Sonic energy has also been employed as a means of atomization. The objective of this study was to examine the effect of nozzle type and design on fish oil encapsulation efficiency and microcapsule properties. A total of 3 nozzle types, a pressure nozzle with 1 liquid channel, a pressure nozzle with 2 liquid channels, and a sonic atomizer with 2 liquid channels were examined for their suitability to encapsulate fish oil in whey protein isolate. Physical and chemical properties of freeze dried microcapsules were compared to those of microcapsules produced by spray drying. The 2-fluid pressure and ultrasonic nozzles had the highest (91.6%) and the lowest microencapsulation efficiencies (76%), respectively. There was no significant difference in bulk density of microcapsules produced by ultrasonic and 3-fluid pressure nozzles. The ultrasonic nozzle showed a significantly narrower particle size distribution than the other nozzles. This study demonstrated that new nozzle designs that eliminate emulsion preparation prior to spray drying can be beneficial for microencapsulation applications. However, there is still a need for research to improve microencapsulation efficiency of multiple channel spray nozzles. Practical Application: Since this research evaluates new spray nozzle designs for oil microencapsulation, the information presented in this article could be an interest to fish oil producers and food industry.

  18. Comparison of Global Sizing Velocimetry and Phase Doppler Anemometry measurements of alternative jet fuel sprays

    Science.gov (United States)

    Sadr, Reza; Kannaiyan, Kumaran

    2013-11-01

    Atomization plays a crucial precursor role in liquid fuel combustion that directly affects the evaporation, mixing, and emission levels. Laser diagnostic techniques are often used to study the spray characteristics of liquid fuels. The objective of this work is to compare the spray measurements of Gas-to Liquid (GTL) jet fuels obtained using Global Sizing Velocimetry (GSV) and Phase Doppler Anemometry (PDA) techniques at global and local levels, respectively. The chemical and physical properties of GTL fuels are different from conventional jet fuels, owing to the difference in their production methodology. In this work, the experimental facility, the measurement techniques, and spray characteristics of two different GTL fuels are discussed and compared with those of Jet A-1 fuel. Results clearly demonstrate that although the global measurement gives an overall picture of the spray, fine details are obtained only through local measurements and complement in gaining more inferences into the spray characteristics. The results also show a close similarity in spray characteristics between GTL and Jet A-1 fuels. Funded by Qatar Science and Technology Park.

  19. Droplet size measurements for spray dryer scale-up.

    Science.gov (United States)

    Thybo, Pia; Hovgaard, Lars; Andersen, Sune Klint; Lindeløv, Jesper Saederup

    2008-01-01

    This study was dedicated to facilitate scale-up in spray drying from an atomization standpoint. The purpose was to investigate differences in operating conditions between a pilot and a production scale nozzle. The intension was to identify the operating ranges in which the two nozzles produced similar droplet size distributions. Furthermore, method optimization and validation were also covered. Externally mixing two-fluid nozzles of similar designs were used in this study. Both nozzles are typically used in commercially available spray dryers, and they have been characterized with respect to droplet size distributions as a function of liquid type, liquid flow rate, atomization gas flow rate, liquid orifice diameter, and atomization gas orifice diameter. All droplet size measurements were carried out by using the Malvern Spraytec with nozzle operating conditions corresponding to typical settings for spray drying. This gave droplets with Sauter Mean Diameters less than 40 microm and typically 5-20 microm. A model previously proposed by Mansour and Chigier was used to correlate the droplet size to the operating parameters. It was possible to make a correlation for water incorporating the droplet sizes for both the pilot scale and the production scale nozzle. However, a single correlation was not able to account properly for the physical properties of the liquid to be atomized. Therefore, the droplet size distributions of ethanol could not be adequately predicted on the basis of the water data. This study has shown that it was possible to scale up from a pilot to production scale nozzle in a systematic fashion. However, a prerequisite was that the nozzles were geometrically similar. When externally mixing two-fluid nozzles are used as atomizers, the results obtained from this study could be a useful guideline for selecting appropriate operating conditions when scaling up the spray-drying process.

  20. An experimental-analytical method to study steady spray combustion.

    Science.gov (United States)

    Bracco, F. V.

    1973-01-01

    Description of a method for determining the local parameters of the gas mixture resulting from the combustion of sprayed fuel in a gaseous oxidizer. The method is based on the measurement of local static pressures in the gas mixture and does not require the knowledge of the droplet distribution function, drag, and vaporization characteristics. A set of equations with substituted local pressure values is used for calculations. Application of the method is demonstrated on a liquid oxygen-ethanol rocket fuel.

  1. The development and application of an automatic boundary segmentation methodology to evaluate the vaporizing characteristics of diesel spray under engine-like conditions

    Science.gov (United States)

    Ma, Y. J.; Huang, R. H.; Deng, P.; Huang, S.

    2015-04-01

    Studying the vaporizing characteristics of diesel spray could greatly help to reduce engine emission and improve performance. The high-speed schlieren imaging method is an important optical technique for investigating the macroscopic vaporizing morphological evolution of liquid fuel, and pre-combustion constant volume combustion bombs are often used to simulate the high pressure and high temperature conditions occurring in diesel engines. Complicated background schlieren noises make it difficult to segment the spray region in schlieren spray images. To tackle this problem, this paper develops a vaporizing spray boundary segmentation methodology based on an automatic threshold determination algorithm. The methodology was also used to quantify the macroscopic characteristics of vaporizing sprays including tip penetration, near-field and far-field angles, and projected spray area and spray volume. The spray boundary segmentation methodology was realized in a MATLAB-based program. Comparisons were made between the spray characteristics obtained using the program method and those acquired using a manual method and the Hiroyasu prediction model. It is demonstrated that the methodology can segment and measure vaporizing sprays precisely and efficiently. Furthermore, the experimental results show that the spray angles were slightly affected by the injection pressure at high temperature and high pressure and under inert conditions. A higher injection pressure leads to longer spray tip penetration and a larger projected area and volume, while elevating the temperature of the environment can significantly promote the evaporation of cold fuel.

  2. Macroscopic Properties of Hollow Cone Spray Using an Outwardly Opening Piezoelectric Injector in GCI Engine

    KAUST Repository

    Cheng, Penghui

    2016-07-01

    Fuel mixture formation and spray characteristics are crucial for the advancement of Gasoline Compression Ignition (GCI) engine. For investigations of spray characteristics, a high-pressure high-temperature spray chamber with constant volume has been designed, tested and commissioned at CCRC, KAUST. Back light illumination technique has been applied to investigate the macroscopic spray properties of an outwardly opening piezoelec- tric injector. Three parameters including injection pressure, ambient pressure, and ambient temperature have been involved. A total of 18 combinations of experimental conditions were tested under non-reactive conditions. Through qualitative analysis of spray morphology under different operating conditions, an apparent distinction of spray morphology has been noticed. Spray morphology and propagation have shown strong dependencies on ambient pressure and ambient tempera- ture while injection pressure has a negligible effect on spray shape. Increasingly compact and bushier spray patterns were observed in the cases of high ambient pressure due to in- creasing aerodynamic drag force on spray boundary. It should also be noted that ambient temperature plays a fairly important role in fuel evaporation rate. At 200 °C, oscillating and considerably short spray shape was produced. Also, circumferential ring-like vortices and distinctive string-like structures have been identified for the fuel spray exiting this hollow cone injector. It has been observed that high ambient pressure conditions (Pamb = 4 bar and 10.5 bar) are favorable to the vortices generation, which has also been reported in previous literature. The quantitative description of macroscopic spray properties reveals that ambient pres- sure and ambient temperature are found to be the most influential parameters on liquid penetration length. The rise of ambient pressure results in considerably shorter liquid pen- etration length. Ambient temperature also appears to be a very effective

  3. Lanthanide-based laser-induced phosphorescence for spray diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Voort, D. D. van der, E-mail: d.d.v.d.voort@tue.nl; Water, W. van de; Kunnen, R. P. J.; Clercx, H. J. H.; Heijst, G. J. F. van [Applied Physics Department, Eindhoven University of Technology, 5612 AZ Eindhoven (Netherlands); Maes, N. C. J.; Sweep, A. M.; Dam, N. J. [Mechanical Engineering Department, Eindhoven University of Technology, 5612 AZ Eindhoven (Netherlands); Lamberts, T. [Institute of Theoretical Chemistry, University of Stuttgart, D-70569 Stuttgart (Germany)

    2016-03-15

    Laser-induced phosphorescence (LIP) is a relatively recent and versatile development for studying flow dynamics. This work investigates certain lanthanide-based molecular complexes for their use in LIP for high-speed sprays. Lanthanide complexes in solutions have been shown to possess long phosphorescence lifetimes (∼1-2 ms) and to emit light in the visible wavelength range. In particular, europium and terbium complexes are investigated using fluorescence/phosphorescence spectrometry, showing that europium-thenoyltrifluoracetone-trioctylphosphineoxide (Eu-TTA-TOPO) can be easily and efficiently excited using a standard frequency-tripled Nd:YAG laser. The emitted spectrum, with maximum intensity at a wavelength of 614 nm, is shown not to vary strongly with temperature (293-383 K). The decay constant of the phosphorescence, while independent of ambient pressure, decreases by approximately 12 μs/K between 323 and 373 K, with the base level of the decay constant dependent on the used solvent. The complex does not luminesce in the gas or solid state, meaning only the liquid phase is visualized, even in an evaporating spray. By using an internally excited spray containing the phosphorescent complex, the effect of vaporization is shown through the decrease in measured intensity over the length of the spray, together with droplet size measurements using interferometric particle imaging. This study shows that LIP, using the Eu-TTA-TOPO complex, can be used with different solvents, including diesel surrogates. Furthermore, it can be easily handled and used in sprays to investigate spray breakup and evaporation.

  4. Study about making and clinical application on the device to spray liquid into uterine cavity and detect the depth of it%多功能子宫腔探测喷灌器制作与临床应用的研究

    Institute of Scientific and Technical Information of China (English)

    黄丽坤; 赵瑞莲; 徐霞; 杜常华; 韩颖

    2008-01-01

    Objective To evaluate the effectiveness of the device to spray liquid into uterine cavity and detect the depth of it. Methods 600 patients were randomized into three groups with 200 cases each. Group Ⅰ received anesthetics with the device to spray liquid into uterine cavity and detect the depth of it. Group Ⅱreceived anesthetics by injecting anesthetics at the side of uterine cervix, Group Ⅲ were not treated with any anesthetics. The degree of pain during enlarging uterine cervix and uterine curettage, the amount of bleeding and the sizes of cervical dilator through uterine cervix with non-resistance were compared between the three groups. Results A significantly alleviated degree of pain during enlarging uterine cervix was observed between group Ⅰ,group Ⅱ and group Ⅲ(P0.05).A significantly alleviated degree of pain during uterine curettage was observed between group Ⅰ and group Ⅱ,group Ⅲ(P0.05).The amount of bleeding in three groups were not observed(P>0.05).The significantly decreased sizes of cervical dilator through uterine cervix with non-resistance were observed between group Ⅰ.groupⅡand group Ⅲ(P0.05).Conclusion The device to spray liquid into uterine cavity and detect the depth of it is applied in clinic,and it has some advantages:narcotism is quick;abirrition is strong;using is convenience;damage is small;application is economical and safety.So it is worthy of widely use.%目的 探讨多功能子宫腔探测喷灌器的研制及临床应用效果.方法 采用随机分组方法将600例研究对象分为三组,每组200例,应用多功能子宫腔探测喷灌器喷灌麻醉药物为Ⅰ组;宫旁注射浸润麻醉为Ⅱ组;术前不用任何药物直接行人工流产术为Ⅲ组.比较三组手术时扩张子宫颈的疼痛程度、吸刮子宫腔时的疼痛程度、术中的出血量、术中无阻力通过宫颈口扩张器的号数.结果 术中扩张子宫颈的疼痛程度Ⅰ组、Ⅱ组均轻于Ⅲ组(P均0.05);吸宫时的

  5. Numerical Study of Suspension Plasma Spraying

    CERN Document Server

    Farrokhpanah, Amirsaman; Mostaghimi, Javad

    2016-01-01

    A numerical study of suspension plasma spraying (SPS) is presented in the current work. The liquid suspension jet is replaced with a train of droplets containing the suspension particles injected into the plasma flow. Atomization, evaporation, and melting of different components are considered for particles as they travel towards the substrate. Effect of different parameters on particle conditions during flight and upon impact on the substrate are investigated. Initially, influence of the torch operating conditions such as inlet flow rate and power are studied. Additionally, effect of injector parameters like injection location, flow rate, and angle are examined. The model used in current study takes high temperature gradients and non-continuum effects into account. Moreover, the important effect of change in physical properties of suspension droplets as a result of evaporation is included in the model. These mainly include variations in heat transfer properties and viscosity. Utilizing this improved model, s...

  6. Variable Gravity Effects on the Cooling Performance of a Single Phase Confined Spray

    Science.gov (United States)

    Michalak, Travis; Yerkes, Kirk; Baysinger, Karri; McQuillen, John

    2005-01-01

    The objective of this paper is to discuss the testing of a spray cooling experiment designed to be flown on NASA's KC-135 Reduced Gravity Testing Platform. Spray cooling is an example of a thermal management technique that may be utilized in high flux heat acquisition and high thermal energy transport concepts. Many researchers have investigated the utility of spray cooling for the thermal management of devices generating high heat fluxes. However, there has been little research addressing the physics and ultimate performance of spray cooling in a variable gravity environment. An experimental package, consisting of a spray chamber coupled to a fluid delivery loop system, was fabricated for variable gravity flight tests. The spray chamber contains two opposing nozzles spraying on target Indium Tin Oxide (ITO) heaters. These heaters are mounted on glass pedestals, which are part of a sump system to remove unconstrained liquid from the test chamber. Liquid is collected in the sumps and returned to the fluid delivery loop. Thermocouples mounted in and around the pedestals are used to determine both the heat loss through the underside of the IT0 heater and the heat extracted by the spray. A series of flight tests were carried out aboard the KC-135, utilizing the ability of the aircraft to produce various gravity conditions. During the flight tests, for a fixed flow rate, heat input was varied at 20, 30, 50, and 80W with variable gravities of 0.01, 0.16, 0.36, and 1.8g. Flight test data was compared to terrestrial baseline data in addition to analytical and numerical solutions to evaluate the heat transfer in the heater and support structure . There were significant differences observed in the spray cooling performance as a result of variable gravity conditions and heat inputs. In general, the Nussult number at the heater surface was found to increase with decreasing gravity conditions for heat loads greater than 30W.

  7. Linear Stability Analysis of Laminar Premixed Fuel-Rich Double-Spray Flames

    Directory of Open Access Journals (Sweden)

    Noam Weinberg

    2014-03-01

    Full Text Available This paper considers the stability of a double-spray premixed flame formed when both fuel and oxidizer are initially present in the form of sprays of evaporating liquid droplets. To simplify the inherent complexity that characterizes the analytic solution of multi-phase combustion processes, the analysis is restricted to fuel-rich laminar premixed double-spray flames, and assumes a single-step global chemical reaction mechanism. Steady-state solutions are obtained and the sensitivity of the flame temperature and the flame propagating velocity to the initial liquid fuel and/or oxidizer loads are established. The stability analysis revealed an increased proneness to cellular instability induced by the presence of the two sprays, and for the fuel-rich case considered here the influence of the liquid oxidizer was found to be more pronounced than that of the liquid fuel. Similar effects were noted for the neutral pulsating stability boundaries. The impact of unequal latent heats of vaporization is also investigated and found to be in keeping with the destabilizing influence of heat loss due to droplet evaporation. It should be noted that as far as the authors are aware no experimental evidence is available for (at least validation of the predictions. However, they do concur in a general and reasonable fashion with independent experimental evidence in the literature of the behavior of single fuel spray laminar premixed flames.

  8. On the Development of Spray Submodels Based on Droplet Size Moments

    Science.gov (United States)

    Beck, J. C.; Watkins, A. P.

    2002-11-01

    Hitherto, all polydisperse spray models have been based on discretising the liquid flow field into groups of equally sized droplets. The authors have recently developed a spray model that captures the full polydisperse nature of the spray flow without using droplet size classes (Beck, 2000, Ph.D thesis, UMIST; Beck and Watkins, 2001, Proc. R. Soc. London A). The parameters used to describe the distribution of droplet sizes are the moments of the droplet size distribution function. Transport equations are written for the two moments which represent the liquid mass and surface area, and two more moments representing the sum of drop radii and droplet number are approximated via use of a presumed distribution function, which is allowed to vary in space and time. The velocities to be used in the two transport equations are obtained by defining moment-average quantities and constructing further transport equations for the relevant moment-average velocities. An equation for the energy of the liquid phase and standard gas phase equations, including a k-ɛ turbulence model, are also solved. All the equations are solved in an Eulerian framework using the finite-volume approach, and the phases are coupled through source terms. Effects such as interphase drag, droplet breakup, and droplet-droplet collisions are also captured through the use of source terms. The development of the submodels to describe these effects is the subject of this paper. All the source terms for the hydrodynamics of the spray are derived in this paper in terms of the four moments of the droplet size distribution in order to find the net effect on the whole spray flow field. The development of similar submodels to describe heat and mass transfer effects between the phases is the subject of a further paper (Beck and Watkins, 2001, J. Heat Fluid Flow). The model has been applied to a wide variety of different sprays, including high-pressure diesel sprays, wide-angle solid-cone water sprays, hollow

  9. Venturi easy ambient sonic-spray ionization.

    Science.gov (United States)

    Santos, Vanessa G; Regiani, Thaís; Dias, Fernanda F G; Romão, Wanderson; Jara, Jose Luis Paz; Klitzke, Clécio F; Coelho, Fernando; Eberlin, Marcos N

    2011-02-15

    The development and illustrative applications of an ambient ionization technique termed Venturi easy ambient sonic-spray ionization (V-EASI) is described. Its dual mode of operation with Venturi self-pumping makes V-EASI applicable to the direct mass spectrometric analysis of both liquid (V(L)-EASI) and solid (V(S)-EASI) samples. V-EASI is simple and easy to assemble, operating solely via the assistance of a sonic stream of nitrogen or air. The sonic gas stream causes two beneficial and integrated effects: (a) the self-pumping of solutions via the Venturi effect and (b) sonic-spray ionization (SSI) of analytes either in solution or resting on solid surfaces. In its liquid mode, V(L)-EASI is applicable to analytes in solution, forming negatively and/or positively charged intact molecular species in a soft fashion with little or no fragmentation. In its solid mode, V(S)-EASI relies on Venturi self-pumping of a proper SSI solvent solution in combination with SSI to form a stream of bipolar charged droplets that bombard the sample surface, causing desorption and ionization of the analyte molecules. As for its precursor technique (EASI), V-EASI generates bipolar droplets with considerably lower average charging, which increases selectivity for ionization with high signal-to-noise ratios and clean spectra dominated by single molecular species with minimal solvent ions. V-EASI also operates in a voltage-, heat-, and radiation-free fashion and is therefore free of thermal, electrical, or discharge interferences.

  10. Electrostatic application of antimicrobial sprays to sanitize food handling and processing surfaces for enhanced food safety

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, Shawn M; Harrison, Mark A [Food Science and Technology Department, University of Georgia, Athens, GA, 30602-2610 (United States); Law, S Edward, E-mail: edlaw@engr.uga.edu [Biological and Agricultural Engineering Department, Applied Electrostatics Laboratory www.ael.engr.uga.edu, University of Georgia, Athens, GA, 30602-4435 (United States)

    2011-06-23

    Human illnesses and deaths caused by foodborne pathogens (e.g., Salmonella enterica, Listeria monocytogenes, Escherichia coli O157:H7, etc.) are of increasing concern globally in maintaining safe food supplies. At various stages of the food production, processing and supply chain antimicrobial agents are required to sanitize contact surfaces. Additionally, during outbreaks of contagious pathogenic microorganisms (e.g., H1N1 influenza), public health requires timely decontamination of extensive surfaces within public schools, mass transit systems, etc. Prior publications verify effectiveness of air-assisted, induction-charged (AAIC) electrostatic spraying of various chemical and biological agents to protect on-farm production of food crops...typically doubling droplet deposition efficiency with concomitant increases in biological control efficacy. Within a biosafety facility this present work evaluated the AAIC electrostatic-spraying process for application of antimicrobial liquids onto various pathogen-inoculated food processing and handling surfaces as a food safety intervention strategy. Fluoroanalysis of AAIC electrostatic sprays (-7.2 mC/kg charge-to-mass ratio) showed significantly greater (p<0.05) mass of tracer active ingredient (A.I.) deposited onto target surfaces at various orientations as compared both to a similar uncharged spray nozzle (0 mC/kg) and to a conventional hydraulic-atomizing nozzle. Per unit mass of A.I. dispensed toward targets, for example, A.I. mass deposited by AAIC electrostatic sprays onto difficult to coat backsides was 6.1-times greater than for similar uncharged sprays and 29.0-times greater than for conventional hydraulic-nozzle sprays. Even at the 56% reduction in peracetic acid sanitizer A.I. dispensed by AAIC electrostatic spray applications, they achieved equal or greater CFU population reductions of Salmonella on most target orientations and materials as compared to uncharged sprays and conventional full-rate hydraulic

  11. Spray granulation: importance of process parameters on in vitro and in vivo behavior of dried nanosuspensions.

    Science.gov (United States)

    Figueroa, Carlos E; Bose, Sonali

    2013-11-01

    The use of fluid bed granulation for drying of pharmaceutical nanoparticulates on micron-sized granule substrates is a relatively new technique, with limited understanding in the current literature of the effects of process parameters on the physical properties of the dried nanoparticle powders. This work evaluated the effects of spray mode, spray rate and atomizing pressure for spray granulation of drug nanosuspensions through a systematic study. Naproxen and a proprietary Novartis compound were converted into nanosuspensions through wet media milling and dried onto a mannitol based substrate using spray granulation. For naproxen, various physical properties of the granules, as well as the in vitro re-dispersion and dissolution characteristics of the nano-crystals, were measured. It was found that the spray mode had the most drastic effect, where top spray yielded smaller re-dispersed particle sizes and faster release rates of drug from granules than bottom spray. This was attributed to the co-current spraying in bottom spray resulting in denser, homogenous films on the substrate. Similar in vitro results were obtained for the proprietary molecule, Compound A. In vivo studies in beagle dogs with Compound A showed no significant difference between the liquid and the dried forms of the nanosuspension in terms of overall AUC, differences were observed in the tmax which correlated with the rank ordering observed from the in vitro dissolution profiles. These findings make spray granulation amenable to the production of powders with desired processing and handling properties, without compromising the overall exposure of the compound under investigation. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Electrostatic application of antimicrobial sprays to sanitize food handling and processing surfaces for enhanced food safety

    Science.gov (United States)

    Lyons, Shawn M.; Harrison, Mark A.; Law, S. Edward

    2011-06-01

    Human illnesses and deaths caused by foodborne pathogens (e.g., Salmonella enterica, Listeria monocytogenes, Escherichia coli O157:H7, etc.) are of increasing concern globally in maintaining safe food supplies. At various stages of the food production, processing and supply chain antimicrobial agents are required to sanitize contact surfaces. Additionally, during outbreaks of contagious pathogenic microorganisms (e.g., H1N1 influenza), public health requires timely decontamination of extensive surfaces within public schools, mass transit systems, etc. Prior publications verify effectiveness of air-assisted, induction-charged (AAIC) electrostatic spraying of various chemical and biological agents to protect on-farm production of food crops...typically doubling droplet deposition efficiency with concomitant increases in biological control efficacy. Within a biosafety facility this present work evaluated the AAIC electrostatic-spraying process for application of antimicrobial liquids onto various pathogen-inoculated food processing and handling surfaces as a food safety intervention strategy. Fluoroanalysis of AAIC electrostatic sprays (-7.2 mC/kg charge-to-mass ratio) showed significantly greater (p<0.05) mass of tracer active ingredient (A.I.) deposited onto target surfaces at various orientations as compared both to a similar uncharged spray nozzle (0 mC/kg) and to a conventional hydraulic-atomizing nozzle. Per unit mass of A.I. dispensed toward targets, for example, A.I. mass deposited by AAIC electrostatic sprays onto difficult to coat backsides was 6.1-times greater than for similar uncharged sprays and 29.0-times greater than for conventional hydraulic-nozzle sprays. Even at the 56% reduction in peracetic acid sanitizer A.I. dispensed by AAIC electrostatic spray applications, they achieved equal or greater CFU population reductions of Salmonella on most target orientations and materials as compared to uncharged sprays and conventional full-rate hydraulic

  13. Characterization of fan spray atomizers through numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Altimira, Mireia [Thermal and Fluids Engineering Division, Mechanical Engineering Department, Tecnun (University of Navarra), Manuel de Lardizabal 13, 20018 San Sebastian (Spain)], E-mail: maltimira@tecnun.es; Rivas, Alejandro; Larraona, Gorka S.; Anton, Raul; Ramos, Juan Carlos [Thermal and Fluids Engineering Division, Mechanical Engineering Department, Tecnun (University of Navarra), Manuel de Lardizabal 13, 20018 San Sebastian (Spain)

    2009-04-15

    The present paper focuses on the mathematical modeling of industrial fan spray atomizers. The two-phase flow taking place inside the nozzle's tip and the exterior region near the outlet of three different industrial nozzle designs has been modeled and simulated. As a result, valuable information has been obtained regarding the influence of the inner geometry on the flow and also the formation and development of the liquid sheet. Characteristic magnitudes such as the discharge coefficient and the liquid sheet thickness factor have been obtained and validated through experimental measurements. The accumulation of liquid at the border of fan-shaped liquid sheets, also known as rim, has been studied in the analyzed designs, revealing the presence of a tangential velocity component in the liquid sheet and a relationship between the incoming flow rate of the rim and the angle of the liquid sheet. The dependence of the results on turbulence modeling has also been analyzed, drawing interesting conclusions regarding their influence on the liquid sheet mean flow characteristics and on the surrounding gas. Thus, the mathematical model developed has been proved to be a useful tool for nozzle manufacturers; it provides the most important characteristic parameters of the liquid sheet formed given certain nozzle geometry and, additionally, those data necessary to carry out studies of instability, breakup and atomization of the liquid sheet.

  14. A compressible real gas eulerian model for LES of fuel sprays

    Science.gov (United States)

    Knudsen, Edward; Doran, Eric

    2015-11-01

    A compressible solver for eulerian multiphase spray simulations is presented. This large eddy simulation solver employs a Peng-Robinson (PR) equation of state to describe mixtures of two species such as liquid dodecane and gaseous nitrogen. Modeling challenges associated with the use of PR are discussed, as are the resource requirements associated with using a compressible formulation to describe liquids when full fuel injector applications are considered. The solver is analyzed using canonical cases and the Spray A experiment from the Engine Combustion Network.

  15. Properties of Spray Dried Food and Spray Drying Characteristics

    Science.gov (United States)

    Katoh, Fumio

    The following conclusions are obtained, studying properties of spray dried food and drying characteristics. (a) Dried particles are similar to spray droplets in size distribution (y=2.5), and particle count distribution is arranged as (dn/dx = ae-bx). (b) The ratio of the particle diameters before and after drying is calculated with moisture before and after drying, and porosity is given as (εp = ww4). (c) The standard drying method is presented to evaluate accurately drying problems at a certain standard. (d) Equilibrium moisture at 20 up to 100°C are summarized in terms of adsorption potential. (e) It makes clear that calulation based on the theory of residence time and drying time represents well complex spray drying characteristics.

  16. Study of droplet size and velocity of fuel containing CO2 spray by means of PDA

    Institute of Scientific and Technical Information of China (English)

    XIAO Jin; QIAO Xinqi; HUANG Zhen; FANG Junhua

    2004-01-01

    Injection of fuel containing CO2 has potential to reduce NOx and soot emissions in a diesel engine. This paper presents an experimental study on the spray characteristics of fuel containing CO2 as measured by phase doppler anemometry (PDA). Experiments were performed under atmospheric conditions on diesel hole-type nozzles at constant injection pressure. Effects of CO2 concentration in diesel fuel on the spray pattern, droplet size and velocity were measured. Experimental results show that fuel atomization will improve greatly when the concentration of dissolved CO2 in the fuel exceeds the critical value. The axial and radial velocity of the fuel spray containing CO2 is larger than that of conventional diesel fuel spray near the nozzle exit due to flash boiling phenomena. Downstream of the spray, the radial velocity and droplet size of fuel containing CO2 is much more uniform and smaller than that of pure diesel spray. It is attributed to the greatly enhanced liquid-gas mixing resulting from flash separation of CO2 from the liquid. New insight into the atomization of the fuel containing CO2 was obtained and a possible mechanism to explain the phenomena was proposed. The method may be developed into a new technique for controlling diesel combustion and exhaust emissions.

  17. Hard tissue ablation with a spray-assisted mid-IR laser

    Energy Technology Data Exchange (ETDEWEB)

    Kang, H W [American Medical Systems, Minnetonka, MN (United States); Rizoiu, I [BioLase Technology, Irvine, CA (United States); Welch, A J [Department of Biomedical Engineering, University of Texas at Austin, Austin, TX (United States)

    2007-12-21

    The objective of this study was to understand the dominant mechanism(s) for dental enamel ablation with the application of water spray. A free-running Er,Cr:YSGG (yttrium, scandium, gallium, garnet) laser was used to ablate human enamel tissue at various radiant exposures. During dental ablation, distilled water was sprayed on the sample surface, and these results were compared to ablation without a spray (dry ablation). In order to identify dominant ablation mechanisms, transient acoustic waves were compared to ablation thresholds and the volume of material removed. The ablation profile and depth were measured using optical coherence tomography (OCT). Irregular surface modification, charring and peripheral cracks were associated with dry ablation, whereas craters for spray samples were relatively clean without thermal damage. In spite of a 60% higher ablation threshold for spray associated irradiations owing to water absorption, acoustic peak pressures were six times higher and ablation volume was up to a factor of 2 larger compared to dry ablation. The enhanced pressure and ablation performance of the spray-assisted process was the result of rapid water vaporization, material ejection with recoil stress, interstitial water explosion and possibly liquid-jet formation. With water cooling and abrasive/disruptive mechanical effects, the spray ablation can be a safe and efficient modality for dental treatment.

  18. NACOM code for analysis of postulated sodium spray fires in LMFBRs

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, S.S.

    1980-03-01

    An analysis of potential sodium spills and fires in liquid metal fast breeder reactors has been made to assess the maximum equipment cell loading conditions. A computer code called NACOM (sodium combustion) has been developed at Brookhaven National Laobratory (BNL) to analyze sodium spray fires. This report contains a detailed description of physical models used in this code as well as programming aspects. The single droplet combustion model and the model describing the droplets' motion are verified. Comparisons between NACOM predictions and SPRAY-3A predictions of the Atomics International (AI) LTV Jet Tests are made. Good agreement is found between the NACOM predictions and the experimental data. NACOM predictions of the pressure rise are more accurate than SPRAY-3A predictions for most of the cases studied. The code has been verified for oxygen concentrations ranging from 0 to 21%. NACOM utilizes more realistic single droplet and spray combustion models than SPRAY-3A. Moreover, NACOM does not utilize adjustable parameters for the burning rate equations, contrary to the approach taken with SPRAY-3A. Thus, the NACOM code is a more reliable code for use in the analysis of large-scale sodium spray fires in LMFBR containment cells. 24 refs., 32 figs.

  19. THE INTERACTION OF A COLD ATOMISED SPRAY WITH A CIRCULAR CYLINDER

    Directory of Open Access Journals (Sweden)

    A. AROUSSI

    2010-09-01

    Full Text Available The development of non-intrusive diagnostic techniques has significantly increased with the introduction of lasers. Laser based anemometry, such as Laser Doppler (LDA, Phase Doppler (PDA, and Particle Image Velocimetery (PIV can provide an accurate description of flows without interference. This study determines experimentally the fluid motion resulting from the interaction of a liquid spray with a circular cylinder. Two experimental settings were examined: the first is a discharging spray into free air and the second is a spray impinging on a circular cylinder placed 25 cylinder diameters downstream of the nozzle. These sprays were quantified using PIV. A non-intrusive droplet sizing technique was used to characterise the spray. This has shown that, within the spray, the average droplet diameter increases when the circular cylinder is introduced and so does the frequency of occurrence of these large droplets. In the wake behind the cylinder, the smaller droplets were quickly entrained and recirculated, while the larger droplets continued in the general direction of the spray cone.

  20. Officials: Aerial Spraying Working Against Miami Mosquitoes

    Science.gov (United States)

    ... 160274.html Officials: Aerial Spraying Working Against Miami Mosquitoes The insects are to blame for first cases ... 2016 (HealthDay News) -- Aerial spraying is killing many mosquitoes in a part of Miami where the insects ...

  1. Computer simulation to arc spraying

    Institute of Scientific and Technical Information of China (English)

    梁志芳; 李午申; 王迎娜

    2004-01-01

    The arc spraying process is divided into two stages: the first stage is atomization-spraying stream (ASS) and the second one is spraying deposition (SD). Then study status is described of both stages' physical model and corresponding controlling-equation. Based on the analysis of study status, the conclusion as follows is got. The heat and mass transfer models with two or three dimensions in ASS stage should be established to far deeply analyses the dynamical and thermal behavior of the overheat droplet. The statistics law of overheated droplets should be further studied by connecting simulation with experiments. More proper validation experiments should be designed for flattening simulation to modify the models in SD stage.

  2. The 2016 Thermal Spray Roadmap

    Science.gov (United States)

    Vardelle, Armelle; Moreau, Christian; Akedo, Jun; Ashrafizadeh, Hossein; Berndt, Christopher C.; Berghaus, Jörg Oberste; Boulos, Maher; Brogan, Jeffrey; Bourtsalas, Athanasios C.; Dolatabadi, Ali; Dorfman, Mitchell; Eden, Timothy J.; Fauchais, Pierre; Fisher, Gary; Gaertner, Frank; Gindrat, Malko; Henne, Rudolf; Hyland, Margaret; Irissou, Eric; Jordan, Eric H.; Khor, Khiam Aik; Killinger, Andreas; Lau, Yuk-Chiu; Li, Chang-Jiu; Li, Li; Longtin, Jon; Markocsan, Nicolaie; Masset, Patrick J.; Matejicek, Jiri; Mauer, Georg; McDonald, André; Mostaghimi, Javad; Sampath, Sanjay; Schiller, Günter; Shinoda, Kentaro; Smith, Mark F.; Syed, Asif Ansar; Themelis, Nickolas J.; Toma, Filofteia-Laura; Trelles, Juan Pablo; Vassen, Robert; Vuoristo, Petri

    2016-12-01

    Considerable progress has been made over the last decades in thermal spray technologies, practices and applications. However, like other technologies, they have to continuously evolve to meet new problems and market requirements. This article aims to identify the current challenges limiting the evolution of these technologies and to propose research directions and priorities to meet these challenges. It was prepared on the basis of a collection of short articles written by experts in thermal spray who were asked to present a snapshot of the current state of their specific field, give their views on current challenges faced by the field and provide some guidance as to the R&D required to meet these challenges. The article is divided in three sections that deal with the emerging thermal spray processes, coating properties and function, and biomedical, electronic, aerospace and energy generation applications.

  3. Spray Drying of High Sugar Content Foods: Improving of Product Yield and Powder Properties

    Directory of Open Access Journals (Sweden)

    Mehmet Koç

    2016-06-01

    Full Text Available Spray drying is the most preferred drying method to produce powdered food in the food industry and it is also widely used to convert sugar-rich liquid foods to a powder form. During and/or after spray drying process of sugar-rich products, undesirable situation was appeared such as stickiness, high moisture affinity (hygroscopicity and low solubility due to low molecular weight monosaccharides that found naturally in the structure. The basis of these problems was formed by low glass transition temperature of sugar-rich products. This review gives information about the difficulties in drying of sugar-rich products via spray dryer, actions need to be taken against these difficulties and drying of sugar-rich honey and fruit juices with spray drying method.

  4. Spray drying for preservation of erythrocytes: effect of atomization on hemolysis.

    Science.gov (United States)

    McLean, Mary; Han, Xiao-Yue; Higgins, Adam Z

    2013-04-01

    Spray drying has the potential to enable storage of erythrocytes at room temperature in the dry state. The spray drying process involves atomization of a liquid into small droplets and drying of the droplets in a gas stream. In this short report, we focus on the atomization process. To decouple atomization from drying, erythrocyte suspensions were sprayed with a two-fluid atomizer nozzle using humid nitrogen as the atomizing gas. The median droplet size was less than 100 μm for all of the spray conditions investigated, indicating that the suspensions were successfully atomized. Hemolysis was significantly affected by the hematocrit of the erythrocyte suspension, the suspension flow rate, and the atomizing gas flow rate (pspray drying may be a feasible option for erythrocyte biopreservation.

  5. Liquid plasma sprayed nano-network La0.4Sr0.6Co0.2Fe0.8O3/Ce0.8Gd0.2O2 composite as a high-performance cathode for intermediate-temperature solid oxide fuel cells

    Science.gov (United States)

    Zhang, Shan-Lin; Li, Chang-Jiu; Li, Cheng-Xin; Yang, Guan-Jun; Huang, Kevin; Liu, Meilin

    2016-09-01

    Here, we investigate the feasibility of using a liquid plasma spray process as a novel method for the cost-effective fabrication of a nanonetwork of La0.4Sr0.6Co0.2Fe0.8O3-δ (LSCF) and Ce0.8Gd0.2O2-δ (GDC) composite as a high-performance cathode for intermediate-temperature solid oxide fuel cells. A suspension containing well-dispersed nanosized GDC particles in an LSCF precursor solution is designed as the feedstock. The effects of GDC concentration in the suspension on the phase composition, microstructure, and electrochemical performance of the resulting cathode are studied. When the GDC concentration increases to 15 g L-1, the nanosized GDC particles distribute uniformly and continuously on the LSCF backbone to form a porous network structure. The electrochemical studies further indicate that the cathode polarization decreased with the increase in GDC concentration from 0 g L-1 to 15 g L-1, whereas a further increase in the GDC concentration increases the cathode polarization instead. At 600 and 750 °C, the cathode prepared using 15 g L-1 GDC concentration exhibits an impressive area-specific polarization resistance (Rp) of 0.1 Ω cm2 and 0.009 Ω cm2, respectively. Finally, the Rp of the optimal cathode almost does not change after the isothermal dwelling at 650 °C for 350 h.

  6. Spray casting project final report

    Energy Technology Data Exchange (ETDEWEB)

    Churnetski, S.R.; Thompson, J.E.

    1996-08-01

    Lockheed Martin Energy Systems, Inc. (Energy Systems), along with other participating organizations, has been exploring the feasibility of spray casting depleted uranium (DU) to near-net shape as a waste minimization effort. Although this technology would be useful in a variety of applications where DU was the material of choice, this effort was aimed primarily at gamma-shielding components for use in storage and transportation canisters for high-level radioactive waste, particularly in the Multipurpose Canister (MPC) application. In addition to the waste-minimization benefits, spray casting would simplify the manufacturing process by allowing the shielding components for MPC to be produced as a single component, as opposed to multiple components with many fabrication and assembly steps. In earlier experiments, surrogate materials were used to simulate the properties (specifically reactivity and density) of DU. Based on the positive results from those studies, the project participants decided that further evaluation of the issues and concerns that would accompany spraying DU was warranted. That evaluation occupied substantially all of Fiscal Year 1995, yielding conceptual designs for both an intermediate facility and a production facility and their associated engineering estimates. An intermediate facility was included in this study to allow further technology development in spraying DU. Although spraying DU to near-net shape seems to be feasible, a number of technical, engineering, and safety issues would need to be evaluated before proceeding with a production facility. This report is intended to document the results from the spray-casting project and to provide information needed by anyone interested in proceeding to the next step.

  7. Polluting emissions reduction and better fuel utilization through spray characterization; Reduccion de emisiones contaminantes y mejor utilizacion del combustible a traves de la caracterizacion de sprays

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Arguelles, Anselmo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1994-01-01

    In this article, to emphasize their importance, the most outstanding aspects of spray characterization and its correlation, when appropriate, with the combustion process of liquid fuels or with the combustion products, are presented. Also, some modern measuring methods more frequently employed for the spray studies, are described. Finally, some examples taken from specialized literature are discussed, with which it is demonstrated that the spray characterization plays a predominant roll in the combustion control and in the reduction of polluting emissions. [Espanol] En este articulo se presentan los aspectos mas sobresalientes de la caracterizacion de sprays, y se correlacionan, cuando es oportuno, con el proceso de la combustion de combustibles liquidos o con los productos de la combustion para enfatizar su importancia. Asimismo, se describen algunos metodos modernos de medicion que con mayor frecuencia se utilizan en el estudio de sprays. Finalmente, se discuten algunos ejemplos tomados de la literatura especializada, con los cuales se demuestra que la caracterizacion de sprays juega un papel preponderante en el control de la combustion y en la reduccion de emisiones contaminantes.

  8. Hollow Cone Spray Characterization and Integral Modeling

    OpenAIRE

    Bollweg, Peter

    2013-01-01

    The thesis presents a computationally efficient spray model for hollow cone sprays suitable for engine system simulation of direct injecting gasoline internal combustion engines. The model describes the transient evolution of the spray as a two-phase jet. Spatial gradients are resolved along the main injection direction. Momentum exchange, droplet heat-up, and fuel evaporation are accounted for. Diffusive transport of momentum, energy, and fuel species mass between the dense spray zone an...

  9. Diesel spray characterization; Dieselmoottorin polttoainesuihkujen ominaisuudet

    Energy Technology Data Exchange (ETDEWEB)

    Pitkaenen, J.; Turunen, R.; Paloposki, T.; Rantanen, P.; Virolainen, T. [Helsinki Univ. of Technology, Otaniemi (Finland). Internal Combustion Engine Lab.

    1997-10-01

    Fuel injection of diesel engines will be studied using large-scale models of fuel injectors. The advantage of large-scale models is that the measurement of large-scale diesel sprays will be easier than the measurement of actual sprays. The objective is to study the break-up mechanism of diesel sprays and to measure drop size distributions in the inner part of the spray. The results will be used in the development of diesel engines and diesel fuels. (orig.)

  10. Generation of 1:1 Carbamazepine:Nicotinamide cocrystals by spray drying.

    Science.gov (United States)

    Patil, Shashank P; Modi, Sameer R; Bansal, Arvind K

    2014-10-01

    The present study investigates the potential of spray drying as a technique for generation of pharmaceutical cocrystals. Carbamazepine-Nicotinamide cocrystal (CNC) was chosen as model cocrystal system for this study. Firstly, CNC was generated using liquid assisted grinding and used for generation of phase solubility diagram (PSD) and ternary phase diagram (TPD). Both PSD and TPD were carefully evaluated for phase behavior of CNC when equilibrated with solvent. The undersaturated region with respect to CNC, as depicted by TPD, was selected as target region to initiate cocrystallization experiments. Various points in this region, representative of different compositions of Carbamazepine, Nicotinamide and CNC, were selected and spray drying was carried out. The spray dried product was characterized for solid state properties and was compared with CNC generated by liquid assisted grinding. Spray drying successfully generated CNC of similar quality as those generated by liquid assisted grinding. Moreover, there was no significant impact of process variables on formation of CNC. Spray drying, owing to its simplicity and industrial scalability, can be a promising method for large scale cocrystal generation.

  11. 14 CFR 27.239 - Spray characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 27.239 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.239 Spray characteristics. If certification for water operation is requested, no spray...

  12. 14 CFR 23.239 - Spray characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 23.239 Section 23.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Handling Characteristics § 23.239 Spray characteristics. Spray may not dangerously obscure the vision...

  13. 14 CFR 29.239 - Spray characteristics.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 29.239 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.239 Spray characteristics. If certification for water operation is requested, no spray...

  14. Application of pulse combustion technology in spray drying process

    Directory of Open Access Journals (Sweden)

    I. Zbicinski

    2000-12-01

    Full Text Available The paper presents development of valved pulse combustor designed for application in drying process and drying tests performed in a specially built installation. Laser technique was applied to investigate the flow field and structure of dispersed phase during pulse combustion spray drying process. PDA technique was used to determine initial atomization parameters as well as particle size distribution, velocity of the particles, mass concentration of liquid phase in the cross section of spray stream, etc., in the drying chamber during drying tests. Water was used to estimate the level of evaporation and 5 and 10% solutions of sodium chloride to carry out drying tests. The Computational Fluid Dynamics technique was used to perform theoretical predictions of time-dependent velocity, temperature distribution and particle trajectories in the drying chamber. Satisfactory agreement between calculations and experimental results was found in certain regions of the drying chamber.

  15. Fuel concentration in isothermal Diesel sprays through structured planar laser imaging measurements

    Energy Technology Data Exchange (ETDEWEB)

    Payri, R.; Gimeno, J.; Marti, P. [CMT Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Manin, J., E-mail: jmanin@sandia.gov [Sandia National Laboratories, 7011 East Ave., 94551 Livermore, CA (United States)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Structured illumination has been implemented to quantify mixing in isothermal sprays. Black-Right-Pointing-Pointer Comparison to a gas-jet model conducted to Schmidt number below the unity (Sc = 0.8). Black-Right-Pointing-Pointer Results showed incomplete momentum transfer due to velocity slip between droplets and ambient. Black-Right-Pointing-Pointer Higher injection pressures enhance momentum transfer and lead to better global mixing. - Abstract: The mixing of isothermal liquid sprays in engine-like conditions has been investigated by applying the structured planar laser imaging technique to remove multiple light scattering. The intensity of the illumination plane has been recovered by removing multiply scattered light and mapping the spray three-dimensionally via discrete tomography. Based on the extinction of light within the illumination plane, the number density has been extracted. Coupled with 2-D maps of droplet diameters obtained through LIF/Mie ratio, the number density allowed to calculate the fuel concentration in the sprays. The mixture fraction of DI Diesel sprays injected into an inert environment held at room temperature has been evaluated and compared to a 2-D model based on gas-jet theory. The experimental results showed good agreement with the predictions when a Gaussian radial distribution is assumed and the Schmidt number is correctly tuned. Differences in the radial distribution has been observed and related to incomplete momentum transfer between the liquid spray and the surrounding gases. For different testing conditions, while the influence of ambient density on mixing was expected, the effect of injection pressure has been found to provide additional information concerning the global mixing of liquid sprays.

  16. Influence of Cold-Sprayed, Warm-Sprayed, and Plasma-Sprayed Layers Deposition on Fatigue Properties of Steel Specimens

    Science.gov (United States)

    Cizek, J.; Matejkova, M.; Dlouhy, I.; Siska, F.; Kay, C. M.; Karthikeyan, J.; Kuroda, S.; Kovarik, O.; Siegl, J.; Loke, K.; Khor, Khiam Aik

    2015-06-01

    Titanium powder was deposited onto steel specimens using four thermal spray technologies: plasma spray, low-pressure cold spray, portable cold spray, and warm spray. The specimens were then subjected to strain-controlled cyclic bending test in a dedicated in-house built device. The crack propagation was monitored by observing the changes in the resonance frequency of the samples. For each series, the number of cycles corresponding to a pre-defined specimen cross-section damage was used as a performance indicator. It was found that the grit-blasting procedure did not alter the fatigue properties of the steel specimens (1% increase as compared to as-received set), while the deposition of coatings via all four thermal spray technologies significantly increased the measured fatigue lives. The three high-velocity technologies led to an increase of relative lives to 234% (low-pressure cold spray), 210% (portable cold spray), and 355% (warm spray) and the deposition using plasma spray led to an increase of relative lives to 303%. The observed increase of high-velocity technologies (cold and warm spray) could be attributed to a combination of homogeneous fatigue-resistant coatings and induction of peening stresses into the substrates via the impingement of the high-kinetic energy particles. Given the intrinsic character of the plasma jet (low-velocity impact of semi/molten particles) and the mostly ceramic character of the coating (oxides, nitrides), a hypothesis based on non-linear coatings behavior is provided in the paper.

  17. Drug distribution in wet granulation: foam versus spray.

    Science.gov (United States)

    Tan, Melvin X L; Nguyen, Thanh H; Hapgood, Karen P

    2013-09-01

    Foam granulation technology is a new wet granulation approach for pharmaceutical formulations. This study evaluates the performance of foam and spray granulation in achieving uniform drug distribution using a model formulation. To observe wetting and nuclei formation, single drop/foam penetration experiments were performed on a static powder bed comprised of varying compositions of hydrophilic/hydrophobic glass ballotini, and hydrophilic lactose/hydrophobic salicylic acid respectively. High shear granulation experiments were performed in a 5L mixer using varying compositions of hydrophilic lactose and hydrophobic salicylic acid. Four percent hydroxylpropyl methylcellulose (HPMC) solution was delivered at 90 g/min as either a foam (92% FQ) or an atomized spray whilst recording impeller power consumption. After drying, the granule size distribution was measured and the granule composition was estimated using gravimetric filtration in methanol. Foam penetration was less dependent on the powder hydrophobicity compared to drop penetration. For glass ballotini powder mixtures, foam induced nucleation created nuclei with relatively uniform structure and size regardless of the powder hydrophobicity. For salicylic acid and lactose mixtures, increasing the proportion of salicylic acid reduced the nuclei granule size for both foam and drop binder addition. The granule drug distribution was not significantly affected by the binder addition method. Processing conditions, including liquid binder amount, impeller speed, wet massing, and the wettability properties of the formulation were the dominant factors for delivering homogeneous granules. The study reveals that foam and spray granulation involve different nucleation mechanisms - spray tends to incur early liquid penetration whereas foam granulation operates well in mechanical dispersion.

  18. Sprayed skin turbine component

    Science.gov (United States)

    Allen, David B

    2013-06-04

    Fabricating a turbine component (50) by casting a core structure (30), forming an array of pits (24) in an outer surface (32) of the core structure, depositing a transient liquid phase (TLP) material (40) on the outer surface of the core structure, the TLP containing a melting-point depressant, depositing a skin (42) on the outer surface of the core structure over the TLP material, and heating the assembly, thus forming both a diffusion bond and a mechanical interlock between the skin and the core structure. The heating diffuses the melting-point depressant away from the interface. Subsurface cooling channels (35) may be formed by forming grooves (34) in the outer surface of the core structure, filling the grooves with a fugitive filler (36), depositing and bonding the skin (42), then removing the fugitive material.

  19. Rotatable fixture for spray coating

    Science.gov (United States)

    Katvala, V.; Porter, E.; Smith, M.

    1979-01-01

    Fixture that rotates about two axes ensures uniform coating and minimizes handling of coated workpiece. Each side of tile is coated in sequence by moving turntables until surface is perpendicular to spray. Process is repeated until desired thickness has built up.

  20. Spray dispersion in a generic premix module for aeroengine combustors; Spray-Dispersion in einem generischen Vormischmodul fuer Flugtriebwerks-Brennkammern

    Energy Technology Data Exchange (ETDEWEB)

    Becker, J.

    2004-08-01

    The liquid fuel placement and fuel spray dispersion in an annular, swirling flow is investigated experimentally. The liquid fuel is injected into the annular airflow in the radial direction by means of plain jet nozzles in the center body. Optical measurement techniques are applied at near-realistic aeroengine operating conditions, particularly at elevated values of air pressure. An investigation of the liquid plain jet in crossflow concerning penetration, break-up and atomization using visualization techniques and phase-Doppler anemometry is followed by the actual investigation of spray dispersion. This includes detailed measurements of the airflow by laser-Doppler anemometry, yielding turbulence data such as velocity fluctuations and length scales. The Stokes number is employed to analyze and interpret the data and transfer the results to a full power operating condition that cannot be investigated experimentally. (orig.)

  1. Numerical Simulations of Evaporating Sprays in High Pressure and Temperature Operating Conditions (Engine Combustion Network [ECN])

    Science.gov (United States)

    2014-05-01

    Universidad Politecnica de Valencia: (a) CPF facility, (b) schematic of CPF setup...the spray dense region. Medical software is used for imaging to reconstruct a three-dimensional time-averaged distribution of liquid mass fraction...National Laboratories (U.S.), IFP (France), Universidad Politecnica de Valencia (Spain), Caterpillar (U.S.), and Eidenhoven University of Technology

  2. Materials as inherent ignition sources for dust explosions during spray drying

    NARCIS (Netherlands)

    Hoogenband, V. van den; Maaijer, M. de; Versloot, N.H.A.

    2010-01-01

    During spray drying where a solution is dispersed in small droplets through a nozzle the liquid evaporates by means of hot air. In a large number of these processes organic materials are processed so three out of four factors for dust explosions to occur are already present. The only thing missing f

  3. Quantification of sauter mean diameter in diesel sprays using scattering-absorption extinction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Gabrielle L; Magnotti, Gina M; Knox, Benjamin W; Genzale, Caroline L; Matusik, Katarzyna E; Duke, Daniel J; Powell, Christopher F; Kastengren, Alan L

    2017-05-18

    Quantitative measurements of the primary breakup process in diesel sprays are lacking due to a range of experimental and diagnostic challenges, including: high droplet number density environments, very small characteristic drop size scales (~1-10 μm), and high characteristic velocities in the primary breakup region (~600 m/s). Due to these challenges, existing measurement techniques have failed to resolve a sufficient range of the temporal and spatial scales involved and much remains unknown about the primary atomization process in practical diesel sprays. To gain a better insight into this process, we have developed a joint visible and x-ray extinction measurement technique to quantify axial and radial distributions of the path-integrated Sauter Mean Diameter (SMD) and Liquid Volume Fraction (LVF) for diesel-like sprays. This technique enables measurement of the SMD in regions of moderate droplet number density, enabling construction of the temporal history of drop size development within practical diesel sprays. The experimental campaign was conducted jointly at the Georgia Institute of Technology and Argonne National Laboratory using the Engine Combustion Network “Spray D” injector. X-ray radiography liquid absorption measurements, conducted at the Advanced Photon Source at Argonne, quantify the liquid-fuel mass and volume distribution in the spray. Diffused back-illumination liquid scattering measurements were conducted at Georgia Tech to quantify the optical thickness throughout the spray. By application of Mie-scatter equations, the ratio of the absorption and scattering extinction measurements is demonstrated to yield solutions for the SMD. This work introduces the newly developed scattering-absorption measurement technique and highlights the important considerations that must be taken into account when jointly processing these measurements to extract the SMD. These considerations include co-alignment of measurements taken at different institutions

  4. Modeling of Diesel Fuel Spray Formation and Combustion in OpenFOAM

    Energy Technology Data Exchange (ETDEWEB)

    Koesters, Anne

    2012-07-01

    The formation, ignition, and combustion of fuel sprays are highly complex processes and the available models have various shortcomings. The development and application of multidimensional CFD models, that describe the different phenomena have rapidly increased through the use of commercial and public software (e.g. Star-CD, KIVA, FIRE and OpenFOAM). The general approach to spray modeling is given by the Eulerian-Lagrangian method, where the gas phase is modeled as a continuum and the droplets are tracked in a Lagrangian way. The accuracy and robustness of today's spray models vary substantially and spray penetration simulations and the levels of spray-generated turbulence are dependent on the discretization. The work presented here deals with the prediction of spray formation and combustion with improved models implemented in the free, open source software package OpenFOAM. The VSB2 spray model was implemented and tested under varying ambient conditions. The design criteria of the model were to be unconditionally robust, have a minimal number of tuning parameters, and be implementable in any CFD software package supporting particle tracking. The main difference between the VSB2 spray model and standard spray models is how the interaction between the liquid fuel and hot gas phase is modeled. In the VSB2 spray model, a 'blob' is defined, containing differently sized droplets; instead of a parcel containing equally sized droplets. Another feature is the definition of a bubble surrounding the blob. The blob just interacts with the gas phase in the bubble instead of with the gas phase in the whole grid cell. The idea is to reduce grid dependency. Furthermore, equilibrium between the blob and the bubble is ensured, which makes the model very robust. Results of spray penetration simulations are compared with data obtained from experiments done at Chalmers Univ. of Technology and with experimental data published by Siebers and Naber from Sandia National

  5. CHARACTERIZATION OF DIESEL SPRAY IMAGES USING THE LOGARITHMIC IMAGE PROCESSING FRAMEWORK

    Directory of Open Access Journals (Sweden)

    Cecile Petit

    2011-05-01

    Full Text Available The increasing levels of emission standards in Diesel Engines require a detailed understanding, combustion and after treatment. This paper focuses on the spray development as one key parameter in the mixture preparation. The presentation of a methodology to differentiate the internal symmetry of spray images taken under different environmental conditions is presented. In a first step, a preprocessing is performed, then an image re-centering is made using the logarithmic average, afterwards different symmetry axes based on grey levels or on the plume boundary are calculated and, finally, the logarithmic distance characterizing the spray plume internal symmetry is computed. This distance gives more importance to the high grey level pixels, so using our optical setup, it characterizes the liquid continuous core symmetry. The methodology relies on the logarithmic image processing framework, providing a set of specific algebraic and functional operations to analyze images. This paper is an application of the logarithmic image processing framework on Diesel spray characterization. This is a step further in the quantitative diesel spray characterization by means of image analysis. The presented method can be applied to Diesel sprays illuminated with polychromatic or monochromatic light, under atmospheric or pressurized conditions.

  6. Recent developments in plasma spray processes for applications in energy technology

    Science.gov (United States)

    Mauer, G.; Jarligo, M. O.; Marcano, D.; Rezanka, S.; Zhou, D.; Vaßen, R.

    2017-03-01

    This work focuses on recent developments of plasma spray processes with respect to specific demands in energy technology. High Velocity Atmospheric Plasma Spraying (HV-APS) is a novel variant of plasma spraying devoted to materials which are prone to oxidation or decomposition. It is shown how this process can be used for metallic bondcoats in thermal barrier coating systems. Furthermore, Suspension Plasma Spraying (SPS) is a new method to process submicron-sized feedstock powders which are not sufficiently flowable to feed them in dry state. SPS is presently promoted by the development of novel torch concepts with axial feedstock injection. An example for a columnar structured double layer thermal barrier coating is given. Finally, Plasma Spray-Physical Vapor Deposition (PS-PVD) is a novel technology operating in controlled atmosphere at low pressure and high plasma power. At such condition, vaporization even of high-melting oxide ceramics is possible enabling the formation of columnar structured, strain tolerant coatings with low thermal conductivity. Applying different conditions, the deposition is still dominated by liquid splats. Such process is termed Low Pressure Plasma Spraying-Thin Film (LPPS-TF). Two examples of applications are gas-tight and highly ionic and electronic conductive electrolyte and membrane layers which were deposited on porous metallic substrates.

  7. Production of dissolvable microneedles using an atomised spray process: effect of microneedle composition on skin penetration.

    Science.gov (United States)

    McGrath, Marie G; Vucen, Sonja; Vrdoljak, Anto; Kelly, Adam; O'Mahony, Conor; Crean, Abina M; Moore, Anne

    2014-02-01

    Dissolvable microneedles offer an attractive delivery system for transdermal drug and vaccine delivery. They are most commonly formed by filling a microneedle mold with liquid formulation using vacuum or centrifugation to overcome the constraints of surface tension and solution viscosity. Here, we demonstrate a novel microneedle fabrication method employing an atomised spray technique that minimises the effects of the liquid surface tension and viscosity when filling molds. This spray method was successfully used to fabricate dissolvable microneedles (DMN) from a wide range of sugars (trehalose, fructose and raffinose) and polymeric materials (polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylmethylcellulose and sodium alginate). Fabrication by spraying produced microneedles with amorphous content using single sugar compositions. These microneedles displayed sharp tips and had complete fidelity to the master silicon template. Using a method to quantify the consistency of DMN penetration into different skin layers, we demonstrate that the material of construction significantly influenced the extent of skin penetration. We demonstrate that this spraying method can be adapted to produce novel laminate-layered as well as horizontally-layered DMN arrays. To our knowledge, this is the first report documenting the use of an atomising spray, at ambient, mild processing conditions, to create dissolvable microneedle arrays that can possess novel, laminate layering.

  8. Intermittent cryogen spray cooling for optimal heat extraction during dermatologic laser treatment

    Science.gov (United States)

    Majaron, Boris; Svaasand, Lars O.; Aguilar, Guillermo; Nelson, J. Stuart

    2002-09-01

    Fast heat extraction is critically important to obtain the maximal benefit of cryogen spray cooling (CSC) during laser therapy of shallow skin lesions, such as port wine stain birthmarks. However, a film of liquid cryogen can build up on the skin surface, impairing heat transfer due to the relatively low thermal conductivity and higher temperature of the film as compared to the impinging spray droplets. In an attempt to optimize the cryogen mass flux, while minimally affecting other spray characteristics, we apply a series of 10 ms spurts with variable duty cycles. Heat extraction dynamics during such intermittent cryogen sprays were measured using a custom-made metal-disc detector. The highest cooling rates were observed at moderate duty cycle levels. This confirms the presence, and offers a practical way to eliminate the adverse effect of liquid cryogen build-up on the sprayed surface. On the other hand, lower duty cycles allow a substantial reduction in the average rate of heat extraction, enabling less aggressive and more efficient CSC for treatment of deeper targets, such as hair follicles.

  9. Cold Spray Forming of Inconel 718

    Science.gov (United States)

    Wong, W.; Irissou, E.; Vo, P.; Sone, M.; Bernier, F.; Legoux, J.-G.; Fukanuma, H.; Yue, S.

    2013-03-01

    Inconel 718 was cold spray formed to a 6-mm thickness on an 8-cm diameter aluminum alloy tube using Sulzer Amdry 1718 powder and the Plasma Giken PCS-1000 cold spray system. The effects of spray particle velocity and post-spray heat treatment were studied. Post-spray annealing was performed from 950 to 1250 °C for 1-2 h. The resulting microstructures as well as the corresponding mechanical properties were characterized. As-sprayed coatings exhibited very low ductility. The tensile strength and ductility of the heat-treated coatings were improved to varying levels depending on the heat-treatment and spray conditions. For coatings sprayed at higher particle velocity and heat treated at 1250 °C for 1 h, an elongation of 24% was obtained. SEM micrographs showed a higher fraction of interparticle metallurgical bonds due to some sintering effect. Corresponding fracture surfaces also revealed a higher fraction of dimple features, typically associated with ductile fracture, in the annealed coatings. The results demonstrate that cold spray forming of Inconel 718 is feasible, and with appropriate heat treatment, metallurgical bonding can be increased. The ductility of the spray-formed samples was comparable to that of the bulk material.

  10. Electrostatic Method to Measure the Size of the Sprayed Droplets

    Directory of Open Access Journals (Sweden)

    Kuna-Broniowski, M.

    2015-11-01

    Full Text Available In the paper is presented the new method the measurement of the main parameters the atomised stream of liquid. This method base on the measurement of the electric charge carried by water drops charged by high voltage. The electrostatic sensor to measure of the droplets size, is associated with precision mechanic system scanning the sprayed surface. The amplified and conditioned signals from electrostatic sensor are send to the computer system equipped in virtual instrument to analyse the size and spatial distribution of droplets. The virtual instrument control also the scanning system.

  11. Sprays and Cartan projective connections

    Science.gov (United States)

    Saunders, D. J.

    2004-10-01

    Around 80 years ago, several authors (for instance H. Weyl, T.Y. Thomas, J. Douglas and J.H.C. Whitehead) studied the projective geometry of paths, using the methods of tensor calculus. The principal object of study was a spray, namely a homogeneous second-order differential equation, or more generally a projective equivalence class of sprays. At around the same time, E. Cartan studied the same topic from a different point of view, by imagining a projective space attached to a manifold, or, more generally, attached to a `manifold of elements'; the infinitesimal `glue' may be interpreted in modern language as a Cartan projective connection on a principal bundle. This paper describes the geometrical relationship between these two points of view.

  12. Modeling of evaporation and oxidation phenomena in plasma spraying of metal powders

    Science.gov (United States)

    Zhang, Hanwei

    Plasma spraying of metals in air is usually accompanied by evaporation and oxidation of the sprayed material. Optimization of the spraying process must ensure that the particles are fully molten during their short residence time in the plasma jet and prior to hitting the substrate, but not overheated to minimize evaporation losses. In atmospheric plasma spraying (ASP), it is also clearly desirable to be able to control the extent of oxide formation. The objective of this work to develop an overall mathematical model of the oxidization and volatilization phenomena involved in the plasma-spraying of metallic particles in air atmosphere. Four models were developed to simulate the following aspects of the atmospheric plasma spraying (APS) process: (a) the particle trajectories and the velocity and temperature profiles in an Ar-H 2 plasma jet, (b) the heat and mass transfer between particles and plasma jet, (c) the interaction between the evaporation and oxidation phenomena, and (d) the oxidation of liquid metal droplets. The resulting overall model was generated by adapting the computational fluid dynamics code FIDAP and was validated by experimental measurements carried out at the collaborating plasma laboratory of the University of Limoges. The thesis also examined the environmental implications of the oxidization and volatilization phenomena in the plasma spraying of metals. The modeling results showed that the combination of the standard k-s model of turbulence and the Boussinesq eddy-viscosity model provided a more accurate prediction of plasma gas behavior. The estimated NOx generation levels from APS were lower than the U.S.E.P.A. emission standard. Either enhanced evaporation or oxidation can occur on the surface of the metal particles and the relative extent is determined by the process parameters. Comparatively, the particle size has the greatest impact on both evaporation and oxidation. The extent of particle oxidation depends principally on gas-liquid

  13. An investigation of flow-limited field-injection electrostatic spraying (FFESS) and its applications to thin film deposition

    Science.gov (United States)

    Singh, Ravindra Pratap

    Electrostatic spraying is the process of controlled disruption of a liquid surface due to excess surface charge density. The technique has found applications in a wide range of fields from agricultural sprays to fuel injectors to colloidal thrusters for space vehicle propulsion. Over the past 20 years, the technique has been intensely studied in material processing for synthesis of ceramic and metal powders, nanoparticles and thin films. The importance of the technique lies in its simple setup, high deposition efficiency, and ambient atmosphere operation. In conventional electrostatic spraying (CESS), one uses a conducting nozzle to charge the liquid, mostly by induction charging. CESS is therefore restricted to the single jet mode of spraying which occurs at low spray currents. It lacks stability and reproducibility in the high current, multiple jet regime, which can generate much finer sprays. In flow-limited field-injection electrostatic spraying (FFESS), one uses a field-injection electrode to stably and controllably inject higher currents into the liquid, a la Fowler-Nordheim, using an otherwise insulating nozzle. This way, it is possible to stably electrospray in the multiple jet mode. In addition to producing much finer sprays, the multi-jet mode atomizes liquids at higher rates, and spreads the spray over a wider region and more uniformly than single jet sprays, thus paving way for large-area uniform thin film deposition. A simple yet comprehensive theory is formulated to describe the multi jet formation. The theory, which is based on the energy minimization principle, takes into account, for the first time, the interactions between charged jets which leads to saturation in the number of jets at high spray currents. The possibility of using an array of nozzles to obtain uniform large-area high-throughput thin film deposition is also investigated. A large number of FFESS nozzles with alternating positive and negative polarities arranged in a periodic 2

  14. Small-Scale Spray Releases: Additional Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, G. N.; Mahoney, Lenna A.; Tran, Diana N.; Burns, Carolyn A.; Kurath, Dean E.

    2013-08-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNL’s test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are largely absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale. The small-scale testing and resultant data are described in Mahoney et al. (2012b) and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used to mimic the

  15. Large-Scale Spray Releases: Additional Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Richard C.; Gauglitz, Phillip A.; Burns, Carolyn A.; Fountain, Matthew S.; Shimskey, Rick W.; Billing, Justin M.; Bontha, Jagannadha R.; Kurath, Dean E.; Jenks, Jeromy WJ; MacFarlan, Paul J.; Mahoney, Lenna A.

    2013-08-01

    One of the events postulated in the hazard analysis for the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak event involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids that behave as a Newtonian fluid. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and in processing facilities across the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNL’s test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are mostly absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale testing. The small-scale testing and resultant data are described in Mahoney et al. (2012b), and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used

  16. Evaluation of the Eulerian-Lagrangian spray atomisation (ELSA) in spray simulations

    OpenAIRE

    Hoyas, S.; Pastor Enguídanos, José Manuel; KHUONG, ANH DUNG; MOMPÓ LABORDA, JUAN MANUEL; Ravet, Frederic

    2011-01-01

    Many approaches have been used to simulate the spray structure especially in modelling fuel sprays, i.e., Eulerian, Lagrangian, Lagrangian- Eulerian, Eulerian-Eulerian and Eulerian-Lagrangian approaches. The present study uses an Eulerian-Lagrangian spray atomisation (ELSA) method which is an integrated model for capturing the whole spray evolution starting directly from injector nozzle still the end. Our goal in this study is to evaluate the ELSA model which is implementing into the commerci...

  17. Numerical Study of Suspension Plasma Spraying

    Science.gov (United States)

    Farrokhpanah, Amirsaman; Coyle, Thomas W.; Mostaghimi, Javad

    2017-01-01

    A numerical study of suspension plasma spraying is presented in the current work. The liquid suspension jet is replaced with a train of droplets containing the suspension particles injected into the plasma flow. Atomization, evaporation, and melting of different components are considered for droplets and particles as they travel toward the substrate. Effect of different parameters on particle conditions during flight and upon impact on the substrate is investigated. Initially, influence of the torch operating conditions such as inlet flow rate and power is studied. Additionally, effect of injector parameters like injection location, flow rate, and angle is examined. The model used in the current study takes high-temperature gradients and non-continuum effects into account. Moreover, the important effect of change in physical properties of suspension droplets as a result of evaporation is included in the model. These mainly include variations in heat transfer properties and viscosity. Utilizing this improved model, several test cases have been considered to better evaluate the effect of different parameters on the quality of particles during flight and upon impact on the substrate.

  18. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  19. Breakup and coalescence characteristics of a hollow cone swirling spray

    Science.gov (United States)

    Saha, Abhishek; Lee, Joshua D.; Basu, Saptarshi; Kumar, Ranganathan

    2012-12-01

    This paper deals with an experimental study of the breakup characteristics of water emanating from hollow cone hydraulic injector nozzles induced by pressure-swirling. The experiments were conducted using two nozzles with different orifice diameters 0.3 mm and 0.5 mm and injection pressures (0.3-4 MPa) which correspond to Rep = 7000-26 000. Two types of laser diagnostic techniques were utilized: shadowgraph and phase Doppler particle anemometry for a complete study of the atomization process. Measurements that were made in the spray in both axial and radial directions indicate that both velocity and average droplet diameter profiles are highly dependent on the nozzle characteristics, Weber number and Reynolds number. The spatial variation of diameter and velocity arises principally due to primary breakup of liquid films and subsequent secondary breakup of large droplets due to aerodynamic shear. Downstream of the nozzle, coalescence of droplets due to collision was also found to be significant. Different types of liquid film breakup were considered and found to match well with the theory. Secondary breakup due to shear was also studied theoretically and compared to the experimental data. Coalescence probability at different axial and radial locations was computed to explain the experimental results. The spray is subdivided into three zones: near the nozzle, a zone consisting of film and ligament regime, where primary breakup and some secondary breakup take place; a second zone where the secondary breakup process continues, but weakens, and the centrifugal dispersion becomes dominant; and a third zone away from the spray where coalescence is dominant. Each regime has been analyzed in detail, characterized by timescale and Weber number and validated using experimental data.

  20. Modeling the influence of nozzle-generated turbulence on diesel sprays

    Energy Technology Data Exchange (ETDEWEB)

    Magnotti, G M; Matusik, K E; Duke, D J; Knox, B W; Martinez, G L; Powell, C F; Kastengren, A L; Genzale, C L

    2017-05-18

    The physical mechanisms governing spray breakup in direct injection engines, such as aerodynamic induced instabilities and nozzle-generated cavitation and turbulence, are not well understood due to the experimental and computational limitations in resolving these processes. Recent x-ray and visible extinction measurements have been con-ducted with a targeted interest in the spray formation region in order to characterize the distribution of droplet sizes throughout the spray. Detailed analysis of these measurements shows promise of yielding insight into likely mechanisms governing atomization, which can inform the improvement of spray models for engine computational fluid dynamic (CFD) codes. In order to investigate potential atomization mechanisms, we employ a joint experimental and computational approach to characterize the structure of the spray formation region using the Engine Combustion Network Spray D injector. X-ray tomography, radiography and ultra-small angle x-ray scattering measurements conducted at the Advanced Photon Source at Argonne National Laboratory quantify the injector geometry, liquid fuel mass and Sauter mean diameter (SMD) distributions under non-vaporizing conditions. Diffused back-illumination imaging measurements, conducted at the Georgia Institute of Technology, characterize the asymmetry of the spray structure. The selected range of injection pressures (50 – 150 MPa) and ambient densities (1.2 – 22.8 kg/m3) allow for the influence of aerodynamic forces on the spray to be studied in a controlled and systematic manner, while isolating the atomization process from the effects of vaporization. In comparison to high ambient density conditions, the spray is observed to be more asymmetric at low ambient density conditions. Although several mechanisms may cause asymmetries in the nozzle exit flow conditions and ultimately the spray distribution, irregularities in the internal nozzle geometry were identified, suggesting an increased

  1. Geometric VOF-PLIC simulations of Hollow Cone Sprays

    Science.gov (United States)

    Nelson, Thomas; Benson, Michael; Vanpoppel, Brett; Bravo, Luis; USMA Team Spray Collaboration; ARL Vehicle Combustion Lab Collaboration; Stanford University Collaboration

    2014-11-01

    This work examines a Computational Fluid Dynamics (CFD) approach to provide temporally resolved simulations of a novel pressure swirl atomizer presently studied at Stanford University. In a pressure swirl atomizer, the liquid spreads out to form an air-cored vortex within the nozzle and an emerging thin annular film. Due to instabilities the film breaks up to form a hollow cone spray. The numerical simulations focus on the near field nozzle flow physics and primary atomization of the spray. An incompressible flow formulation is adopted with a geometric unsplit Volume of Fluid (VOF) method to track the interface between two immiscible fluids in interfacial flow simulations. Here, the interface is modeled via an advection equation implicitly tracked using a discrete indicator function, f, with values representing the volume fraction of the tagged fluid within a cell. An Adaptive Mesh Refinement (AMR) scheme is also employed to efficiently capture the shear layers near the liquid-gas interface. The study is carried out for two atomizers with 2 mm and 3 mm diameters at intermediate Re = 2.6-3.9 × 103, We = 0.11-0.17 × 105. An in depth comparison is then provided between the CFD results and measurements obtained via shadowgraphy and CT scans.

  2. Designing CAF-adjuvanted dry powder vaccines: Spray drying preserves the adjuvant activity of CAF01

    DEFF Research Database (Denmark)

    Ingvarsson, Pall Thor; Schmidt, Signe Tandrup; Christensen, Dennis

    2013-01-01

    spray drying. The optimal excipient to stabilize CAF01 during spray drying and for the design of nanocomposite microparticles was identified among mannitol, lactose and trehalose. Trehalose and lactose were promising stabilizers with respect to preserving liposome size, as compared to mannitol......Dry powder vaccine formulations are highly attractive due to improved storage stability and the possibility for particle engineering, as compared to liquid formulations. However, a prerequisite for formulating vaccines into dry formulations is that their physicochemical and adjuvant properties...... remain unchanged upon rehydration. Thus, we have identified and optimized the parameters of importance for the design of a spray dried powder formulation of the cationic liposomal adjuvant formulation 01 (CAF01) composed of dimethyldioctadecylammonium (DDA) bromide and trehalose 6,6′-dibehenate (TDB) via...

  3. Development of a model for spray evaporation based on droplet analysis

    KAUST Repository

    Chen, Q.

    2016-08-20

    Extreme flash evaporation occurs when superheated liquid is sprayed into a low pressure zone. This method has high potential to improve the performance of thermally-driven desalination plants. To enable a more in-depth understanding on flash evaporation of a superheated feed water spray, a theoretical model has been developed with key considerations given to droplet motion and droplet size distribution. The model has been validated against 14 experimental data sets from literature sources to within 12% discrepancy. This model is capable of accurately predicting the water productivity and thermal efficiency of existing spray evaporator under specific operating conditions. Employing this model, the effect of several design parameters on system performance was investigated. Key results revealed that smaller droplet enabled faster evaporation process while higher initial droplet velocity promoted water productivity. Thermal utilization marginally changes with the degree of superheat, which renders a quick design calculation of the brine temperature without the need for iterations. © 2016 Elsevier B.V.

  4. New tools to optimise spray dryers

    NARCIS (Netherlands)

    Verschueren, M.; Straatsma, J.; Schutyser, M.A.I.; Akkerman, C.; Jong, de P.

    2007-01-01

    Spray drying is an essential unit operation for the manufacture of many products with specific powder properties. It is characterised by atomisation of a solution or suspension into droplets, followed by subsequent drying of these droplets by evaporation of water or other solvents. Spray drying is u

  5. Uniform spray coating for large tanks

    Science.gov (United States)

    Carter, J. M.

    1977-01-01

    System employs spray facility located within ventilated plastic booth to uniformly coat exterior of large cylindrical tanks with polyurethane foam insulation. Coating target is rotated on turntable while movable spray guns apply overlapping spirals of foam. Entire operation may be controlled by single operator from remote station.

  6. Microgravity Spray Cooling Research for High Powered Laser Applications

    Science.gov (United States)

    Zivich, Chad P.

    2004-01-01

    some heat transfer calculations and picked out a heater to order for the rig. I learned QBasic programming language to change the operating code for our drops, allowing us to rapidly cycle the spray nozzle open and closed to study the effects. We have derived an equation for flow rate vs. pressure for our experiment. We have recorded several videos of drops at different pressures, some with heated test plate and some without, and have noticed substantial differences in the liquid behavior. I have also changed the computer program to write a file with temperature vs. time profiles for the test plate, and once the necessary thermocouple comes in (it was ordered last week), we will have temperature profiles to accompany the videos. Once we have these temperature profiles to go with the videos, we will be able to see how the temperature is affected by the spray at different pressures, and how the spray changes its behavior once as the plate changes from hot to cool. With quantitative temperature data, we can then mathematically model the heat transfer from the plate to the cooling spray. Finally, we can look at the differences between trials in microgravity and those in normal earth gravity.

  7. Characterisation of salmon calcitonin in spray-dried powder for inhalation. Effect of chitosan.

    Science.gov (United States)

    Yang, M; Velaga, S; Yamamoto, H; Takeuchi, H; Kawashima, Y; Hovgaard, L; van de Weert, M; Frokjaer, S

    2007-03-01

    Salmon calcitonin (sCT) powders suitable for inhalation, containing chitosan and mannitol as absorption enhancer and protection agent, respectively, were prepared using a spray-drying process. The effect of chitosan on physicochemical stability of sCT in the dry powder was investigated by different analytical techniques. High-performance liquid chromatography (HPLC) analysis indicated that sCT was chemically stable upon spray-drying. With the proportion of chitosan in spray-drying formulation being increased, dissolution of sCT from the dry powders was decreased both in phosphate buffer and acetate buffer. The thioflavine T fluorescence assay showed that no fibrils were present in the spray-dried powder. However, sCT partly fibrillated in the phosphate buffer, but not in acetate buffer. Fourier transform infrared (FTIR) spectra showed that the secondary structure of sCT was slightly changed in the dry powder, yet no aggregate signal was observed. Circular dichroism analysis indicated that the structure of sCT in an aqueous formulation was slightly altered by addition of chitosan. Nevertheless, recovery of sCT was not influenced by chitosan in the aqueous formulation as indicated by HPLC analysis. This study suggested that sCT, in absence of any additives, was stable during the spray-drying process under certain conditions. Addition of chitosan affects recovery of sCT from spray-dried powders, which may be due to formation of a partially irreversible complex between the protein and chitosan during the spray-drying process.

  8. Spray-coating for biopharmaceutical powder formulations: beyond the conventional scale and its application.

    Science.gov (United States)

    Maa, Yuh-Fun; Ameri, Mahmoud; Rigney, Robert; Payne, Lendon G; Chen, Dexiang

    2004-03-01

    Fluid-bed spray-coating process is widely used to prepare non-protein pharmaceutical solid dosage forms using macro-size seed particles (200-1000 microm) at kilogram batch sizes. In this study we developed a small-scale fluid-bed spray-coating process (20 g) to produce micro-sized vaccine powder formulations (40-60 microm) for epidermal powder immunization (EPI) METHODS: A bench-top spray coater was used to spray two vaccines, diphtheria toxoid (dT) and alum-adsorbed hepatitis-B surface antigen (Alum-HBsAg), onto crystalline lactose particles of 40-60 microm in diameter. Particle properties such as particle size, surface morphology, and degree of particle agglomeration were determined. Protein stability was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The immunogenicity of the vaccine was evaluated in vivo by needle injection and epidermal powder immunization (EPI) of mice or guinea pigs. Coating feasibility was demonstrated for both vaccine formulations containing different excipients. However, the nature of the vaccine antigen appeared to affect coating feasibility in terms of particle agglomeration considerably. Delivery of spray-coated dT and alum-HBsAg through EPI to mice and guinea pigs, respectively, generated significant antibody responses, at a level comparable to liquid formulation delivered subcutaneously through needle/syringe injection. The new spray-coating process represents an important technical advance and may provide a useful tool for developing high-valued biopharmaceutical powder formulations for novel applications. The strong in vivo performance of the coated dT and alum-HBsAg powders by EPI further demonstrated that spray-coating is a viable dry powder formulation process and the skin's epidermal layer presents an efficient vaccine delivery route.

  9. Standardization of spray-dried powder of Piper betle hot water extract.

    Science.gov (United States)

    Arawwawala, Liyanage Dona Ashanthi Menuka; Hewageegana, Horadugoda Gamage Sujatha Pushpakanthi; Arambewela, Lakshmi Sriyani Rajapaksha; Ariyawansa, Hettiarachchige Sami

    2011-04-01

    The leaves of Piper betle Linn. (Family: Piperaceae) possess several bioactivities and are used in the Traditional Medical systems of Sri Lanka. The present investigation was carried out to standardize the spray-dried powder of P. betle by (a) determination of physicochemical parameters, presence or absence of heavy metals, and microbial contamination; (b) screening for phytochemicals; and (c) development of High Pressure Liquid Chromatography (HPLC) fingerprint and densitogram. The percentages of moisture content, total ash, acid insoluble ash, water-soluble ash, and ethanol extractable matter of spray-dried powder of P. betle were 2.2-2.5, 6.8-7.0, 0.003-0.005, 4.1-4.3, and 15.8-16.2, respectively. The concentrations of all the tested heavy metals were below the WHO acceptable limits and bacterial species, such as Escherichia coli, Salmonella spp, Staphylococcus aureus, and Pseudomonas aeroginosa were not present in the P. betle spray-dried powder. Phenolic compounds, tannins, flavonoids steroids, and alkaloids were found to be present in the spray-dried powder of P. betle and HPLC fingerprint and densitogram clearly demonstrated the proportional differences of these chemical constituents. In conclusion, the results obtained from this study can be used to standardize the spray-dried powder of P. betle.

  10. INFLUENCE OF THE SHELL MATERIAL IN THE MICROCAPSULES FORMATION BY SPRAY DRYING

    Directory of Open Access Journals (Sweden)

    FERRÁNDIZ Marcela

    2015-05-01

    Full Text Available Microencapsulation is a process of entrapment, packaging or immobilizing an active (core material, which can be in the state of solid, liquid or gas, within a more stable, protective secondary (wall material that can be released at controlled rates under specific conditions. There are several microencapsulation techniques such as: spray drying, spray cooling/chilling, freeze drying, extrusion, fluidized bed coating, coacervation, liposome entrapment, coextrusion, interfacial polymerization, radical polymerization, molecular inclusion in cyclodextrins, etc. Spray drying has been commonly applied due to their simplicity process, wide availability of equipment facilities, significant merits in terms of reductions in product volume, easy of handling, etc. In the spray drying process the wall materials (shells and their properties are parameters to be considered to achieve proper encapsulation of the active ingredients (core materials. Some commonly used wall materials and their properties related to spray drying encapsulation, including proteins, carbohydrates, and other materials, or mixtures of some of them. Proper encapsulation of the active ingredient (core is essential to achieve this active material protecting the outer. The aim of this work is encapsulated an essential oil, sage oil, using two differet wall materials in order to determine which is the best wall material. Scanning electron microscopy (SEM has been used in order to know the microcapsules morphology. Core, Shell, Gum Arabic, Alginate, Sage oil, Scanning Electron Microscopy (SEM

  11. Standardization of spray-dried powder of Piper betle hot water extract

    Directory of Open Access Journals (Sweden)

    Liyanage Dona Ashanthi Menuka Arawwawala

    2011-01-01

    Full Text Available The leaves of Piper betle Linn. (Family: Piperaceae possess several bioactivities and are used in the Traditional Medical systems of Sri Lanka. The present investigation was carried out to standardize the spray-dried powder of P. betle by (a determination of physicochemical parameters, presence or absence of heavy metals, and microbial contamination; (b screening for phytochemicals; and (c development of High Pressure Liquid Chromatography (HPLC fingerprint and densitogram. The percentages of moisture content, total ash, acid insoluble ash, water-soluble ash, and ethanol extractable matter of spray-dried powder of P. betle were 2.2-2.5, 6.8-7.0, 0.003-0.005, 4.1-4.3, and 15.8-16.2, respectively. The concentrations of all the tested heavy metals were below the WHO acceptable limits and bacterial species, such as Escherichia coli, Salmonella spp, Staphylococcus aureus, and Pseudomonas aeroginosa were not present in the P. betle spray-dried powder. Phenolic compounds, tannins, flavonoids steroids, and alkaloids were found to be present in the spray-dried powder of P. betle and HPLC fingerprint and densitogram clearly demonstrated the proportional differences of these chemical constituents. In conclusion, the results obtained from this study can be used to standardize the spray-dried powder of P. betle.

  12. On the role of physiochemical properties on evaporation behavior of DISI biofuel sprays

    Science.gov (United States)

    Knorsch, Tobias; Heldmann, Markus; Zigan, Lars; Wensing, Michael; Leipertz, Alfred

    2013-06-01

    Biofuels and alternative fuels are increasingly being blended to conventional gasoline fuel to reduce the overall CO2 emissions. The effect on NOx and soot formation is still unclear as the atomization and evaporation of gasoline with biocomponents differ depending on fuel specific physiochemical properties. This work focuses on describing the biofuel evaporation behavior of gasoline sprays at homogeneous charge (early injection timing) and stratified-charge conditions (late injection timing mode) used in modern direct injection spark ignition engines (DISI). A spray plume of a 6-hole solenoid injector is analyzed in terms of liquid spray propagation, and local droplet sizes studied in an injection chamber. Depending on the operating conditions, different physiochemical properties are found to dominate the atomization and evaporation processes: For low and moderate ambient temperature and pressure, high-boiling point components show a strong influence on the spray droplet size distribution. However, at elevated temperature and pressure, the evaporation behavior changes completely. Due to a high degree of evaporation, the evaporation cooling effect dominates the local droplet sizes. Fuel mixtures owing a larger heat of vaporization show larger droplet sizes—even if these fuels have a lower boiling point. Depending on the local evaporation behavior, the different remaining droplet momentum in the spray controls the air entrainment and the subsequent progress of evaporation and mixing. Overall, it can be stated that the heat of vaporization is a dominating physiochemical property for the droplet evaporation rate at high-level supercharged conditions.

  13. Functional and physicochemical properties of whole egg powder: effect of spray drying conditions.

    Science.gov (United States)

    Koç, Mehmet; Koç, Banu; Susyal, Gonca; Sakin Yilmazer, Melike; Kaymak Ertekin, Figen; Bağdatlıoğlu, Neriman

    2011-04-01

    Pasteurized liquid whole egg was subjected to spray drying to determine the effect of spray drying conditions on moisture content, water activity, peroxide value, emulsion stability, gel texture, foaming stability and colour change of the powder product. Drying process was carried out in a pilot scale spray dryer (Mobile Minor Niro-Atomizer, Denmark). The inlet (165-195 °C) and outlet air temperatures (60-80 °C) and the atomization pressure (196-392 kPa) were investigated as spray drying process variables. Perturbation and 3-D graphs revealed that outlet air temperature and atomization pressure had more effect than inlet air temperature, on the properties of whole egg powder. Optimum spray drying conditions of whole egg powder were determined according to the specific end-product requirements (bakery foods, omelette and mayonnaise and salad dressing) targeting to obtain the desired value of functional properties, i.e.; emulsion stability, gel texture, foaming stability and colour change.

  14. Ways of intensifying liquid dispersion in gas flow

    Science.gov (United States)

    Bazarov, V. G.

    Ways of intensifying liquid dispersion in gas flow are examined with a view to increasing the efficiency of the existing atomizing nozzles. It is noted that the most economical method of dispersion intensification, without using any additional power, is the excitation of auto-oscillations in liquid and gas flows. Several methods of generating auto-oscillations in commonly used centrifugal nozzles are discussed. Other developments include the spraying of viscous and contaminated fluids in a field of forced pressure, velocity, and vorticity fluctuations, and also gas saturation of liquids prior to spraying in nozzles with porous elements.

  15. Experimental investigations of cryogenic sprays in combustion; Travaux experimentaux d'analyse granulometrique des ecoulements cryogeniques en combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tanguy, B.; Vingert, L.; Gicquel, P. [Office National d' Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France); Onofri, F. [Universite de Provence, IUSTI, Aix-Marseille 1, 13 (France)

    2001-07-01

    Three test runs have been performed since 1995 with the cryogenic bench 'Mascotte' of the Onera center of Palaiseau (France) which aimed at characterizing the granulometry of the burning liquid oxygen spray. Experimental qualitative information about the atomization process and the behaviour of the spray at 0.1, 1, 3, and 6 MPa has been obtained using different visualization techniques. A quantitative characterization of the liquid oxygen spray has been obtained for 0.1 and 1 MPa using the phases method (PDPA). This characterization has led to the mapping of the size and velocity of burning droplets for the two pressure values considered. The influence of the momentum ratio on the primary atomization has been demonstrated. More recently, a 2-D laser velocimetry campaign has been performed for the determination of the local Weber number inside the combustion chamber. (J.S.)

  16. Laboratory Injector for Spray Studies Related to Liquid Propellant Gun

    Science.gov (United States)

    1991-02-01

    CODE Ap edfor publi iuleau diatulbwio unlimiu&. 13. ABSTRACT (Maximum 200 worck) Fm orh jnpue of suatuin a a ebomty scale Injectij on F. mypical of a...geometry mode K ..................................... 3 lb Injector attachment for annular geometry mode J...Figure 2. The major parts and features of the injector are identified on both Figures 1 and 2. The injector has three modes of operation K , J, and L

  17. Liquid Spray Characterization in Flow Fields with Centripetal Acceleration

    Science.gov (United States)

    2014-03-27

    Richardson for his unparalleled help and patience while teaching me how to conduct experiments using Phase Doppler Particle Anemometry. He spent...to more hardware. Knowing the thermodynamic benefits of the reheat cycle, W.A. Sirignano, J. P. Delplanque, and F. Liu [5], performed a... thermodynamic analysis of an engine utilizing a reheat cycle. For the analysis, the reheating took place between the high pressure turbine (HPT) and low

  18. Spray formation: an inverse cascade

    CERN Document Server

    Ling, Yue; Tryggvason, Gretar; zaleski, Stephane

    2015-01-01

    We present a study of droplet formation in a gas-liquid mixing layer using direct numerical simulation. It is seen that two mechanisms compete to generate the droplets: fingering at the tip of the waves and hole formation in the thin liquid sheet. The three dimensional liquid structures are much shorter than the longitudinal wavelength of the instability at the first instant of their formation. As time evolves, the structures evolves to larger and larger scales, in a way similar to the inverse cascade of length scales in droplet impact and impact crown formation.

  19. On the modeling of fuel sprays

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Christer

    1997-12-01

    This report concerns on the modelling of fuel sprays in a non-combustible case using an own developed fuel spray code module. The spray code is made as an independent module to simplify the use of different gas flow solvers together with the spray module. This enables the possibility to use different turbulence models. In the report two turbulence models has been used, the standard k-{epsilon} and the LES (Large Eddy Simulation) model. The report presents results obtained from a sensitivity study of both numerical and physical parameters on an evaporating spray under diesel like conditions (light duty diesel engine) with the spray code module attached to a cylindrical gas phase flow solver. The results from the sensitivity analysis showed that these effects were not so pronounced as has been reported. It was suggested that this was due to the `easy` nature of the investigated case, where the flow field could be sufficiently resolved without violating the droplet void fraction criteria and break-up, collision and combustion that may increase the grid spacing sensitivity were not modelled. An investigation was performed to valuate the feasibility of using LES as turbulence model. Calculations of the initial phase of a developing jet were made and it was found that in the initial phase of the spray and the flow structure were similar to that of a spatially developing jet flow, which is in agreement with experimental observations. Results from LES calculations on a developing spray jet was also compared with k-{epsilon} based ones. This result showed that the spray-LES approach captured the transition from a laminar to a turbulent flow field with an increase in turbulent kinetic energy k along the injection direction 45 refs, 37 figs, 2 tabs

  20. Comments to "Analysis of constant rate period of spray drying of slurry" by Liang et al., 2001

    DEFF Research Database (Denmark)

    Jørgensen, Kåre; Jensen, Anker Degn; Sloth, Jakob;

    2006-01-01

    In the study by Liang et al. [2001. Analysis of constant rate period of spray drying of slurry. Chemical Engineering Science 56, 2205-2213] the Darcy flow of liquid through a pore system of primary particles to the surface of a slurry droplet was applied for the constant rate period. Steep primary...

  1. Comments to ”Analysis of constant rate period of spray drying of slurry” by Liang et al

    DEFF Research Database (Denmark)

    Jørgensen, Kåre; Jensen, Anker; Sloth, Jakob;

    2006-01-01

    In the study by Liang et al. [2001. Analysis of constant rate period of spray drying of slurry. Chemical Engineering Science 56, 2205-2213] the Darcy flow of liquid through a pore system of primary particles to the surface of a slurry droplet was applied for the constant rate period. Steep primary...

  2. Sea Spray Generation at a Rocky Shoreline

    Science.gov (United States)

    2015-07-01

    Report 3. DATES COVERED (From - To) 6/15/2012 – 9/15/2015 4. TITLE AND SUBTITLE “Sea Spray Generation at a Rocky Shoreline ” 5a. CONTRACT...this project. The paper, “Sea Spray Generation at Rocky Shoreline ” by Ed Andreas was accepted for publication and as of July 2016 was being...13 Sea Spray Generation at a Rocky Shoreline 14 15 16 17 Edgar L Andreas 18 19 NorthWest Research Associates, Inc. 20 Lebanon, New

  3. Core Length and Spray Width Measurements in Shear Coaxial Rocket Injectors from X-ray Radiography Measurements

    Science.gov (United States)

    2015-05-01

    combustion applications, such as rockets, this region is also the area of flame holding, and so is of primary im- portance in predicting combustion...spray and dividing by the liquid-mass-flow rate allows a mass-averaged liquid velocity to be calculated . In the recent years x-ray radiography has...efficient, and ρl is the density of the absorbing fluid (in this case demineralized water). The mass attenuation coefficient can be calculated using

  4. Dispersed-phase structure of pressure-atomized sprays at various gas densities

    Science.gov (United States)

    Tseng, L.-K.; Wu, P.-K.; Faeth, G. M.

    1992-01-01

    The dispersed-phase structure of the dense-spray region of pressure-atomized sprays was studied for atomization breakup conditions, considering large-scale (9.5 mm initial diameter) water jets in still air at ambient pressures of 1, 2, and 4 atm., with both fully-developed turbulent pipe flow and nonturbulent slug flow at the jet exit. Drop sizes and velocities, and liquid volume fractions and fluxes, were measured using holography. Measurements were compared with predictions based on the locally-homogeneous flow approximation as well as recent correlations of drop sizes after primary breakup of turbulent and nonturbulent liquids. The dispersed-flow region beyond the liquid surface was relatively dilute (liquid volume fractions less than 0.1 percent), with significant separated-flow effects throughout, and evidence of near-limit secondary breakup and drop deformation near the liquid surface. Turbulent primary breakup predictions were satisfactory at atmospheric pressure, where the correlation was developed, but failed to predict observed trends of decreasing drop sizes with increasing gas density due to aerodynamic effects; in contrast, the laminar primary breakup predictions successfully treated the relatively small effects of gas density for this breakup mechanism. Effects of liquid turbulence at the jet exit were qualitatively similar to single-phase flows, yielding faster mixing rates with increased turbulence levels even though drop sizes tended to increase as well.

  5. Evaluation of Convergent Spray Technology(TM) Spray Process for Roof Coating Application

    Science.gov (United States)

    Scarpa, J.; Creighton, B.; Hall, T.; Hamlin, K.; Howard, T.

    1998-01-01

    The overall goal of this project was to demonstrate the feasibility of(CST) Convergent Spray Technology (Trademark) for the roofing industry. This was accomplished by producing an environmentally compliant coating utilization recycled materials, a CST(Trademark) spray process portable application cart, and hand-held applicator with a CST(Trademark) spray process nozzle. The project culminated with application of this coating to a nine hundred sixty square foot metal for NASA Marshall Space Flight Center (MSFC) in Huntsville, Alabama.

  6. Very Low Volatile Organic Compound Spray Application Process for Iron Filled Elastomeric Coatings

    Science.gov (United States)

    2006-05-31

    painting industry (aircraft, furniture, and automotive), the consumer product industry ( deodorants , hair sprays, topical anesthetics and antiseptics...Pro-Engineer software module. The atomizer is constructed primarily out of aluminum . The atomizer has a top plate which is interchangeable for...and liquid is fed through the inner tube. The inner tube is constructed out of brass. All other parts of the atomizer are made with aluminum

  7. The Effect of Swirl on Gas-Centered Swirl Coaxial Injector Sprays

    Science.gov (United States)

    2011-10-13

    ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Air Force Research Laboratory (AFMC) AFRL/RZSA 10 E. Saturn Blvd. Edwards AFB CA 93524-7680...only the lip thickness and liquid inlets are altered. The basic, constant geometry parameters are given in Table 1. Table 2 lists the variations...the film being atomized is also very unstable without swirl [5]. The centripetal acceleration stabilizes the film and, therefore, the spray. The

  8. Toluene removal by oxidation reaction in spray wet scrubber: experimental, modeling and optimization

    Directory of Open Access Journals (Sweden)

    Roumporn Nikom

    2006-11-01

    Full Text Available Toluene, an important volatile organic compound (VOC, is used in many kinds of industries, such as painting, printing, coating, and petrochemical industries. The emission of toluene causes serious air pollution, odor problem, flammability problem and affects human health. This paper proposes the removal of toluene from waste air using a spray wet scrubber combining the absorption and oxidation reaction. Aqueous sodium hypochlorite (NaOCl solution was used as the scrubbing liquid in the system. NaOCl, the strongest oxidative agent, presents an effective toluene removal. As the scrubbed toluene is reacted, recirculation of the scrubbing liquid could be operated with a constant removal efficiency throughout the operting time. The investigated variables affecting the removal efficiency were air flow rate, inlet toluene concentration, NaOCl concentration, scrubbing liquid flow rate and size of spray nozzle. Influence of the scrubbing parameters was experimentally studied to develop a mathematical model of the toluene removal efficiency. The removal model reveals that the increase of scrubbing liquid flow rate, toluene concentration, and NaOCl concentration together with the decrease of air flow rate and size of spray nozzle can increase the toluene removal efficiency. Optimization problem with an objective function and constraints was set to provide the maximum toluene removal efficiency and solved by Matlab optimization toolbox. The optimization constraints were formed from the mathematical model and process limitation. The solution of the optimization was an air flow rate of 100 m3/h, toluene concentration of 1500 ppm, NaOCl concentration of 0.02 mol/l, NaOCl solution feed rate of 0.8 m3/h, and spray nozzle size of 0.5 mm. Solution of the optimization gave the highest toluene removal efficiency of 91.7%.

  9. Experimental research on spray and combustion characteristics of the third generation conical spray

    Institute of Scientific and Technical Information of China (English)

    FENG Li-yan; LONG Wu-qiang; DU Bao-guo; TIAN hua; OBOKATA Tomio

    2005-01-01

    A new generation conical spray system for conventional diesel engines or premixed combustion diesel engines is introduced. By means of oriented impingement method, flexible spray penetration in design is realized. High-speed photograph was used to investigate the spatial distribution characteristics of the new spray for cases of different impingement angles and needle valve opening pressures. The results show that, by applying spray impingement orientation, fuel jets spread along the cone surface as shape of sectors, so the dispersion of jets is increased obviously. Changing on impingement angle leads to variation of penetration, which is critical in homogeneous mixture preparation. Due to the flexibility of spray penetration in design, the spray impingement on liner is avoided in a great extent. The results also indicate that higher needle valve opening pressure results in longer penetration and larger spray angle after impingement. Combustion characteristics of the impinged conical spray were studied in the 1135 type diesel engine. The new impinged conical spray system work smoothly in full load range with better fuel economy and lower emissions of NOx and soot than the original test engine.

  10. COUPLED ATOMIZATION AND SPRAY MODELLING IN THE SPRAY FORMING PROCESS USING OPENFOAM

    DEFF Research Database (Denmark)

    Gjesing, Rasmus; Hattel, Jesper Henri; Fritsching, Udo

    2009-01-01

    The paper presents a numerical model capable of simulating the atomization, break-up and in-flight spray phenomena in the spray forming process. The model is developed and implemented in the freeware code openFOAM. The focus is on studying the coupling effect of the melt break-up phenomena...... model for droplet cooling and solidification. The model is tested and validated against results from literature and experiments. Subsequently, the model is used to simulate the complex flow fields in the spray forming process and the results are discussed. The presented model of the spray forming...

  11. Layered growth with bottom-spray granulation for spray deposition of drug.

    Science.gov (United States)

    Er, Dawn Z L; Liew, Celine V; Heng, Paul W S

    2009-07-30

    The gap in scientific knowledge on bottom-spray fluidized bed granulation has emphasized the need for more studies in this area. This paper comparatively studied the applicability of a modified bottom-spray process and the conventional top-spray process for the spray deposition of a micronized drug during granulation. The differences in circulation pattern, mode of growth and resultant granule properties between the two processes were highlighted. The more ordered and consistent circulation pattern of particles in a bottom-spray fluidized bed was observed to give rise to layered granule growth. This resulted in better drug content uniformity among the granule batches and within a granule batch. The processes' sensitivities to wetting and feed material characteristics were also compared and found to differ markedly. Less robustness to differing process conditions was observed for the top-spray process. The resultant bottom-spray granules formed were observed to be less porous, more spherical and had good flow properties. The bottom-spray technique can thus be potentially applied for the spray deposition of drug during granulation and was observed to be a good alternative to the conventional technique for preparing granules.

  12. Direct morphological comparison of vacuum plasma sprayed and detonation gun sprayed hydroxyapatite coatings for orthopaedic applications.

    Science.gov (United States)

    Gledhill, H C; Turner, I G; Doyle, C

    1999-02-01

    Hydroxyapatite coatings on titanium substrates were produced using two thermal spray techniques vacuum plasma spraying and detonation gun spraying. X-ray diffraction was used to compare crystallinity and residual stresses in the coatings. Porosity was measured using optical microscopy in conjunction with an image analysis system. Scanning electron microscopy and surface roughness measurements were used to characterise the surface morphologies of the coatings. The vacuum plasma sprayed coatings were found to have a lower residual stress, a higher crystallinity and a higher level of porosity than the detonation gun coatings. It is concluded that consideration needs to be given to the significance of such variations within the clinical context.

  13. Spray cooling simulation implementing time scale analysis and the Monte Carlo method

    Science.gov (United States)

    Kreitzer, Paul Joseph

    Spray cooling research is advancing the field of heat transfer and heat rejection in high power electronics. Smaller and more capable electronics packages are producing higher amounts of waste heat, along with smaller external surface areas, and the use of active cooling is becoming a necessity. Spray cooling has shown extremely high levels of heat rejection, of up to 1000 W/cm 2 using water. Simulations of spray cooling are becoming more realistic, but this comes at a price. A previous researcher has used CFD to successfully model a single 3D droplet impact into a liquid film using the level set method. However, the complicated multiphysics occurring during spray impingement and surface interactions increases computation time to more than 30 days. Parallel processing on a 32 processor system has reduced this time tremendously, but still requires more than a day. The present work uses experimental and computational results in addition to numerical correlations representing the physics occurring on a heated impingement surface. The current model represents the spray behavior of a Spraying Systems FullJet 1/8-g spray nozzle. Typical spray characteristics are indicated as follows: flow rate of 1.05x10-5 m3/s, normal droplet velocity of 12 m/s, droplet Sauter mean diameter of 48 microm, and heat flux values ranging from approximately 50--100 W/cm2 . This produces non-dimensional numbers of: We 300--1350, Re 750--3500, Oh 0.01--0.025. Numerical and experimental correlations have been identified representing crater formation, splashing, film thickness, droplet size, and spatial flux distributions. A combination of these methods has resulted in a Monte Carlo spray impingement simulation model capable of simulating hundreds of thousands of droplet impingements or approximately one millisecond. A random sequence of droplet impingement locations and diameters is generated, with the proper radial spatial distribution and diameter distribution. Hence the impingement, lifetime

  14. Water Reclamation using Spray Drying Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a new spray drying technology for the recovery and recycle of water while stabilizing the solid wastes or residues as found in advanced life support...

  15. Spray drying formulation of amorphous solid dispersions.

    Science.gov (United States)

    Singh, Abhishek; Van den Mooter, Guy

    2016-05-01

    Spray drying is a well-established manufacturing technique which can be used to formulate amorphous solid dispersions (ASDs) which is an effective strategy to deliver poorly water soluble drugs (PWSDs). However, the inherently complex nature of the spray drying process coupled with specific characteristics of ASDs makes it an interesting area to explore. Numerous diverse factors interact in an inter-dependent manner to determine the final product properties. This review discusses the basic background of ASDs, various formulation and process variables influencing the critical quality attributes (CQAs) of the ASDs and aspects of downstream processing. Also various aspects of spray drying such as instrumentation, thermodynamics, drying kinetics, particle formation process and scale-up challenges are included. Recent advances in the spray-based drying techniques are mentioned along with some future avenues where major research thrust is needed.

  16. Spot Spraying Reduces Herbicide Concentrations in Runoff.

    Science.gov (United States)

    Melland, Alice R; Silburn, D Mark; McHugh, Allen D; Fillols, Emilie; Rojas-Ponce, Samuel; Baillie, Craig; Lewis, Stephen

    2016-05-25

    Rainfall simulator trials were conducted on sugar cane paddocks across dry-tropical and subtropical Queensland, Australia, to examine the potential for spot spraying to reduce herbicide losses in runoff. Recommended rates of the herbicides glyphosate, 2,4-D, fluoroxypyr, atrazine, and diuron were sprayed onto 0, 20, 40, 50, 70, or 100% of the area of runoff plots. Simulated rainfall was applied 2 days after spraying to induce runoff at one plant cane and three ratoon crop sites. Over 50% of all herbicides were transported in the dissolved phase of runoff, regardless of the herbicide's sediment-water partition coefficient. For most sites and herbicides, runoff herbicide concentrations decreased with decreasing spray coverage and with decreasing herbicide load in the soil and cane residues. Importantly, sites with higher infiltration prior to runoff and lower total runoff had lower runoff herbicide concentrations.

  17. Properties of Plasma and HVOF Sprayed Coatings

    Directory of Open Access Journals (Sweden)

    Wojciech Żórawski

    2012-11-01

    Full Text Available The work compares the properties of plasma and HVOF thermally sprayed coatings obtained by blending the NiCrBSi and Fe2O3 powders. The deposition was performed by means of the Plancer PN-120 and the Diamond Jet guns for plasma spraying and HVOF spraying respectively. The SEM (EDS method was employed to study the microstructure of the produced coatings. Although the blended powders differ in particle size, shape, and distribution, it is possible to obtain composite coatings with an NiCrBSi matrix containing iron oxides. Except for a different microstructure, plasma and HVOF coatings have a different phase composition, which was examined using the Bruker D-8 Advance diffractometer. Studies of the coatings wear and scuffing resistance showed that an optimal content of Fe2O3 is about 26 % for plasma sprayed coatings and 22.5 % for HVOF deposited coatings.

  18. Water Reclamation using Spray Drying Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This purpose of this project is to develop a spray drying prototype to for the recovery and recycle of water from concentrated waste water recovery system brine....

  19. Characterization of High-Velocity Solution Precursor Flame-Sprayed Manganese Cobalt Oxide Spinel Coatings for Metallic SOFC Interconnectors

    Science.gov (United States)

    Puranen, Jouni; Laakso, Jarmo; Kylmälahti, Mikko; Vuoristo, Petri

    2013-06-01

    A modified high-velocity oxy-fuel spray (HVOF) thermal spray torch equipped with liquid feeding hardware was used to spray manganese-cobalt solutions on ferritic stainless steel grade Crofer 22 APU substrates. The HVOF torch was modified in such a way that the solution could be fed axially into the combustion chamber through 250- and 300-μm-diameter liquid injector nozzles. The solution used in this study was prepared by diluting nitrates of manganese and cobalt, i.e., Mn(NO3)2·4H2O and Co(NO3)2·6H2O, respectively, in deionized water. The as-sprayed coatings were characterized by X-ray diffraction and field-emission scanning electron microscopy operating in secondary electron mode. Chemical analyses were performed on an energy dispersive spectrometer. Coatings with remarkable density could be prepared by the novel high-velocity solution precursor flame spray (HVSPFS) process. Due to finely sized droplet formation in the HVSPFS process and the use of as delivered Crofer 22 APU substrate material having very low substrate roughness ( R a < 0.5 μm), thin and homogeneous coatings, with thicknesses lower than 10 μm could be prepared. The coatings were found to have a crystalline structure equivalent to MnCo2O4 spinel with addition of Co-oxide phases. Crystallographic structure was restored back to single-phase spinel structure by heat treatment.

  20. Computational sensitivity study of spray dispersion and mixing on the fuel properties in a gas turbine combustor

    Science.gov (United States)

    Grosshans, Holger; Cao, Le; Fuchs, Laszlo; Szász, Robert-Zoltán

    2017-04-01

    A swirl stabilized gas turbine burner has been simulated in order to assess the effects of the fuel properties on spray dispersion and fuel-air mixing. The properties under consideration include fuel surface tension, viscosity and density. The turbulence of the gas phase is modeled applying the methodology of large eddy simulation whereas the dispersed liquid phase is described by Lagrangian particle tracking. The exchange of mass, momentum and energy between the two phases is accounted for by two-way coupling. Bag and stripping breakup regimes are considered for secondary droplet breakup, using the Reitz-Diwakar and the Taylor analogy breakup models. Moreover, a model for droplet evaporation is included. The results reveal a high sensitivity of the spray structure to variations of all investigated parameters. In particular, a decrease in the surface tension or the fuel viscosity, or an increase in the fuel density, lead to less stable liquid structures. As a consequence, smaller droplets are generated and the overall spray surface area increases, leading to faster evaporation and mixing. Furthermore, with the trajectories of the small droplets being strongly influenced by aerodynamic forces (and less by their own inertia), the spray is more affected by the turbulent structures of the gaseous phase and the spray dispersion is enhanced.

  1. Accurate level set method for simulations of liquid atomization☆

    Institute of Scientific and Technical Information of China (English)

    Changxiao Shao; Kun Luo; Jianshan Yang; Song Chen; Jianren Fan

    2015-01-01

    Computational fluid dynamics is an efficient numerical approach for spray atomization study, but it is chal enging to accurately capture the gas–liquid interface. In this work, an accurate conservative level set method is intro-duced to accurately track the gas–liquid interfaces in liquid atomization. To validate the capability of this method, binary drop collision and drop impacting on liquid film are investigated. The results are in good agreement with experiment observations. In addition, primary atomization (swirling sheet atomization) is studied using this method. To the swirling sheet atomization, it is found that Rayleigh–Taylor instability in the azimuthal direction causes the primary breakup of liquid sheet and complex vortex structures are clustered around the rim of the liq-uid sheet. The effects of central gas velocity and liquid–gas density ratio on atomization are also investigated. This work lays a solid foundation for further studying the mechanism of spray atomization.

  2. The Effect of Water Spray upon Incineration Flue Gas Clean—up

    Institute of Scientific and Technical Information of China (English)

    HaigangWang; BinLi; 等

    2000-01-01

    The existence of liquid water was found very important in incineration flue gas clean-up systems for enhancing the absorption of acid components contained.In a newly developed incineration flue gas clean-up tower,which works in a semi-dry mode,the water is injected in the form of spray to maximum its contact surface with the gas.The criteria for the design of the water nozzles would be high water concentration but no liquid impinging on the solid wall and complete evaporation inside the tower,In order to optimize the atomizer design,the effects of the spray type (hollow or solid cone),their initial droplet size distribution and water flow rate on the performance of the acid gas absorption were investigated.The liquid behaviour was studied with a fluid dynamic simulation code,and the overall performance was checked experimentally.This paper presents the use of a commercial CFD code,FLUENT,and some modifications made during such investigation.The modification includes the viscosity of the flue gas defined as a function of the temperature,and the initial mass fraction of different droplet size group described with an exponential distribution formula of Rosin-Rammler.The investigation results (the optimal spray parameters)were used to guide the water nozzle design.The general performance of the flue gas clean-up system measured during the plant operation complied with the design criteria.

  3. Atypical presentations of methemoglobinemia from benzocaine spray.

    Science.gov (United States)

    Tantisattamo, Ekamol; Suwantarat, Nuntra; Vierra, Joseph R; Evans, Samuel J

    2011-06-01

    Widely used for local anesthesia, especially prior to endoscopic procedures, benzocaine spray is one of the most common causes of iatrogenic methemoglobinemia. The authors report an atypical case of methemoglobinemia in a woman presenting with pale skin and severe hypoxemia, after a delayed repeat exposure to benzocaine spray. Early recognition and prompt management of methemoglobinemia is needed in order to lessen morbidity and mortality from this entity.

  4. Plasma sprayed coatings on crankshaft used steels

    Science.gov (United States)

    Mahu, G.; Munteanu, C.; Istrate, B.; Benchea, M.

    2017-08-01

    Plasma spray coatings may be an alternative to conventional heat treatment of main journals and crankpins of the crankshaft. The applications of plasma coatings are various and present multiple advantages compared to electric arc wire spraying or flame spraying. The study examines the layers sprayed with the following powders: Cr3C2- 25(Ni 20Cr), Al2O3- 13TiO2, Cr2O3-SiO2- TiO2 on the surface of steels used in the construction of a crankshaft (C45). The plasma spray coatings were made with the Spray wizard 9MCE facility at atmospheric pressure. The samples were analyzed in terms of micro and morphological using optical microscopy, scanning electron microscopy and X-ray diffraction. Wear tests on samples that have undergone simulates extreme working conditions of the crankshafts. In order to emphasize adherence to the base material sprayed layer, were carried out tests of microscratches and micro-indentation. Results have showed a relatively compact morphological aspect given by the successive coatings with splat-like specific structures. Following the microscratch analysis it can be concluded that Al2O3-13TiO2 coating has a higher purpose in terms of hardness compared to Cr3C2-(Ni 20Cr) and Cr2O3-SiO2- TiO2 powders. Thermal coatings of the deposited powders have increased the mechanical properties of the material. The results stand to confirm that plasma sprayed Al2O3-13TiO2 powder is in fact a efficient solution for preventing mechanical wear, even with a faulty lubrication system.

  5. Treatment of gingival hyperpigmentation by open spray cryotherapy

    Directory of Open Access Journals (Sweden)

    Belkız Uyar

    2013-03-01

    Full Text Available Background and Design: Although gingival hyperpigmentation is not a medical problem, people who have moderate or severe gingival pigmentation, particularly patients having a gummy smile, frequently request cosmetic treatment. For gingival depigmentation, different treatment modalities have been reported such as surgical treatment, cryotherapy, electrosurgery, and laser therapy. Materials and Methods: Twenty-one patients with gingival melanin pigmentation were included in the study. We applied liquid nitrogen to the hyperpigmented area for 5-10 seconds using open spray technique with a cryogun. Clinical observations for intensity of pigmentation were recorded at baseline and 3 months after the treatment. Clinical parameters, such as bleeding, swelling, redness, and healing, were evaluated immediately after the cryotherapy and 24 hours, and 1 week after the treatment. We used a numeric pain scale to evaluate the pain level. Results: Three months after the treatment, the mean gingival melanin pigmentation score decreased from 41.62±16.58 to 19.28±11.85. The difference between pretreatment and posttreatment mean scores was found to be statistically significant.Discussion: Removal of gingival melanin pigmentation can be performed safely by open spray cryotherapy in dermatology clinics.

  6. Preparation of nanoscale pulmonary drug delivery formulations by spray drying.

    Science.gov (United States)

    Bohr, Adam; Ruge, Christian A; Beck-Broichsitter, Moritz

    2014-01-01

    Advances in preparation technologies for nanomedicines have provided novel formulations for pulmonary drug delivery. Application of drugs via the lungs can be considered as one of the most attractive implementations of nanoparticles for therapeutic use due to the unique anatomy and physiology of the lungs. The colloidal nature of nanoparticles provides important advantages to the formulation of drugs, which are normally difficult to administer due to poor stability or uptake, partly because nanoparticles protect the drug from the physiological milieu, facilitate transport across biological barriers and can offer controlled drug release. There are numerous methods for producing therapeutic nanoparticles, each with their own advantages and suitable application. Liquid atomization techniques such as spray drying can produce nanoparticle formulations in a dry powder form suitable for pulmonary administration in a direct one-step process. This chapter describes the different state-of-the-art techniques used to prepare drug nanoparticles (with special emphasize on spray drying techniques) and the strategies for administering such unique formulations to the pulmonary environment.

  7. Current Status of Superheat Spray Modeling With NCC

    Science.gov (United States)

    Raju, M. S.; Bulzan, Dan L.

    2012-01-01

    An understanding of liquid fuel behavior at superheat conditions is identified to be a topic of importance in the design of modern supersonic engines. As a part of the NASA's supersonics project office initiative on high altitude emissions, we have undertaken an effort to assess the accuracy of various existing CFD models used in the modeling of superheated sprays. As a part of this investigation, we have completed the implementation of a modeling approach into the national combustion code (NCC), and then applied it to investigate the following three cases: (1) the validation of a flashing jet generated by the sudden release of pressurized R134A from a cylindrical nozzle, (2) the differences between two superheat vaporization models were studied based on both hot and cold flow calculations of a Parker-Hannifin pressure swirl atomizer, (3) the spray characteristics generated by a single-element LDI (Lean Direct Injector) experiment were studied to investigate the differences between superheat and non-superheat conditions. Further details can be found in the paper.

  8. IMPACT OF TEHNICAL SPRAYING FACTORS ON LEAF AREA COVERAGE IN PERMANENT CROPS

    Directory of Open Access Journals (Sweden)

    Vjekoslav Tadić

    2013-12-01

    Full Text Available Researches are conducted in vineyard and apple orchard with two different types of mist blowers, axial (Hardi Zaturn and radial (Hardi Arrow. The influence of major technical spraying factors (type of nozzle, working speed and spray volume were observed on coverage of the treated area, average droplet diameter, number of droplets per cm2 and drift. The working speed of sprayer was set at 6 and 8 km/h, and spray volume on 250, 325 and 400 l/ha for apple orchard and 250, 300 and 350 l/ha for vineyard. Researchers used Lechler blue (TR 8003, yellow (TR 8002 and green (TR 80015 nozzles. The research was set as three - factorial field experiment with 18 treatments in 4 repetitions, for different type of sprayer and permanent crops. We used 60 water sensitive papers for that treatment, which were processed with digital image analysis and ImageJ software. In addition to the main features of the research, research showed leaf area index and density, speed and flow of air current, working pressure, orientation of the nozzles and weather conditions, which were monitored during the study. Before the research, mist blowers are tested according to the European standard 13790. By decreasing the ISO number of nozzles and by increasing the working speed and spray volume, we found increase of area coverage, number of droplets per cm2and drift, and decrease of average droplet diameter. Also, by comparing the results of research exploitation by axial and radial mist blower in the vineyards and apple orchards, better results are achieved with radial mist blower (Hardi Arrow in both cases. The best relationship of area coverage and liquid drift in vineyard were achieved with 64.22% area coverage and 17.11% of liquid drift (green nozzle, working speed of 6 km/h, spray volume of 350 l/ha, and working pressure of 10.99 bar. In apple orchard the best relationship of area coverage and liquid drift were achieved with 59.55% area coverage and 21.10% of liquid drift (green

  9. Numerical modeling for dilute and dense sprays

    Science.gov (United States)

    Chen, C. P.; Kim, Y. M.; Shang, H. M.; Ziebarth, J. P.; Wang, T. S.

    1992-01-01

    We have successfully implemented a numerical model for spray-combustion calculations. In this model, the governing gas-phase equations in Eulerian coordinate are solved by a time-marching multiple pressure correction procedure based on the operator-splitting technique. The droplet-phase equations in Lagrangian coordinate are solved by a stochastic discrete particle technique. In order to simplify the calculation procedure for the circulating droplets, the effective conductivity model is utilized. The k-epsilon models are utilized to characterize the time and length scales of the gas phase in conjunction with turbulent modulation by droplets and droplet dispersion by turbulence. This method entails random sampling of instantaneous gas flow properties and the stochastic process requires a large number of computational parcels to produce the satisfactory dispersion distributions even for rather dilute sprays. Two major improvements in spray combustion modelings were made. Firstly, we have developed a probability density function approach in multidimensional space to represent a specific computational particle. Secondly, we incorporate the Taylor Analogy Breakup (TAB) model for handling the dense spray effects. This breakup model is based on the reasonable assumption that atomization and drop breakup are indistinguishable processes within a dense spray near the nozzle exit. Accordingly, atomization is prescribed by injecting drops which have a characteristic size equal to the nozzle exit diameter. Example problems include the nearly homogeneous and inhomogeneous turbulent particle dispersion, and the non-evaporating, evaporating, and burning dense sprays. Comparison with experimental data will be discussed in detail.

  10. Designing CAF-adjuvanted dry powder vaccines: spray drying preserves the adjuvant activity of CAF01.

    Science.gov (United States)

    Ingvarsson, Pall Thor; Schmidt, Signe Tandrup; Christensen, Dennis; Larsen, Niels Bent; Hinrichs, Wouter Leonardus Joseph; Andersen, Peter; Rantanen, Jukka; Nielsen, Hanne Mørck; Yang, Mingshi; Foged, Camilla

    2013-05-10

    Dry powder vaccine formulations are highly attractive due to improved storage stability and the possibility for particle engineering, as compared to liquid formulations. However, a prerequisite for formulating vaccines into dry formulations is that their physicochemical and adjuvant properties remain unchanged upon rehydration. Thus, we have identified and optimized the parameters of importance for the design of a spray dried powder formulation of the cationic liposomal adjuvant formulation 01 (CAF01) composed of dimethyldioctadecylammonium (DDA) bromide and trehalose 6,6'-dibehenate (TDB) via spray drying. The optimal excipient to stabilize CAF01 during spray drying and for the design of nanocomposite microparticles was identified among mannitol, lactose and trehalose. Trehalose and lactose were promising stabilizers with respect to preserving liposome size, as compared to mannitol. Trehalose and lactose were in the glassy state upon co-spray drying with the liposomes, whereas mannitol appeared crystalline, suggesting that the ability of the stabilizer to form a glassy matrix around the liposomes is one of the prerequisites for stabilization. Systematic studies on the effect of process parameters suggested that a fast drying rate is essential to avoid phase separation and lipid accumulation at the surface of the microparticles during spray drying. Finally, immunization studies in mice with CAF01 in combination with the tuberculosis antigen Ag85B-ESAT6-Rv2660c (H56) demonstrated that spray drying of CAF01 with trehalose under optimal processing conditions resulted in the preservation of the adjuvant activity in vivo. These data demonstrate the importance of liposome stabilization via optimization of formulation and processing conditions in the engineering of dry powder liposome formulations.

  11. Characteristics of MCrAlY coatings sprayed by high velocity oxygen-fuel spraying system

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Y.; Saitoh, M.; Tamura, M.

    2000-01-01

    High velocity oxygen-fuel (HVOF) spraying system in open air has been established for producing the coatings that are extremely clean and dense. It is thought that the HVOF sprayed MCrAlY (M is Fe, Ni and/or Co) coatings can be applied to provide resistance against oxidation and corrosion to the hot parts of gas turbines. Also, it is well known that the thicker coating can be sprayed in comparison with any other thermal spraying systems due to improved residual stresses. However, thermal and mechanical properties of HVOF coatings have not been clarified. Especially, the characteristics of residual stress, that are the most important property from the view point of production technique, have not been made clear. In this paper, the mechanical properties of HVOF sprayed MCrAlY coatings were measured in both the case of as-sprayed and heat-treated coatings in comparison with a vacuum plasma sprayed MCrAlY coatings. It was confirmed that the mechanical properties of HVOF sprayed MCrAlY coatings could be improved by a diffusion heat treatment to equate the vacuum plasma sprayed MCrAlY coatings. Also, the residual stress characteristics were analyzed using a deflection measurement technique and a X-ray technique. The residual stress of HVOF coating was reduced by the shot-peening effect comparable to that of a plasma spray system in open air. This phenomena could be explained by the reason that the HVOF sprayed MCrAlY coating was built up by poorly melted particles.

  12. Thin Film CuInS2 Prepared by Spray Pyrolysis with Single-Source Precursors

    Science.gov (United States)

    Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Cowen, Jonathan E.; Hepp, Aloysius F.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Both horizontal hot-wall and vertical cold-wall atmospheric chemical spray pyrolysis processes deposited near single-phase stoichiometric CuInS2 thin films. Single-source precursors developed for ternary chalcopyrite materials were used for this study, and a new liquid phase single-source precursor was tested with a vertical cold-wall reactor. The depositions were carried out under an argon atmosphere, and the substrate temperature was kept at 400 C. Columnar grain structure was obtained with vapor deposition, and the granular structure was obtained with (liquid) droplet deposition. Conductive films were deposited with planar electrical resistivities ranging from 1 to 30 Omega x cm.

  13. The effect of feed solids concentration and inlet temperature on the flavor of spray dried whey protein concentrate.

    Science.gov (United States)

    Park, Curtis W; Bastian, Eric; Farkas, Brian; Drake, MaryAnne

    2014-01-01

    Previous research has demonstrated that unit operations in whey protein manufacture promote off-flavor production in whey protein. The objective of this study was to determine the effects of feed solids concentration in liquid retentate and spray drier inlet temperature on the flavor of dried whey protein concentrate (WPC). Cheddar cheese whey was manufactured, fat-separated, pasteurized, bleached (250 ppm hydrogen peroxide), and ultrafiltered (UF) to obtain WPC80 retentate (25% solids, wt/wt). The liquid retentate was then diluted with deionized water to the following solids concentrations: 25%, 18%, and 10%. Each of the treatments was then spray dried at the following temperatures: 180 °C, 200 °C, and 220 °C. The experiment was replicated 3 times. Flavor of the WPC80 was evaluated by sensory and instrumental analyses. Particle size and surface free fat were also analyzed. Both main effects (solids concentration and inlet temperature) and interactions were investigated. WPC80 spray dried at 10% feed solids concentration had increased surface free fat, increased intensities of overall aroma, cabbage and cardboard flavors and increased concentrations of pentanal, hexanal, heptanal, decanal, (E)2-decenal, DMTS, DMDS, and 2,4-decadienal (P < 0.05) compared to WPC80 spray dried at 25% feed solids. Product spray dried at lower inlet temperature also had increased surface free fat and increased intensity of cardboard flavor and increased concentrations of pentanal, (Z)4-heptenal, nonanal, decanal, 2,4-nonadienal, 2,4-decadienal, and 2- and 3-methyl butanal (P < 0.05) compared to product spray dried at higher inlet temperature. Particle size was higher for powders from increased feed solids concentration and increased inlet temperature (P < 0.05). An increase in feed solids concentration in the liquid retentate and inlet temperature within the parameters evaluated decreased off-flavor intensity in the resulting WPC80.

  14. Numerical modeling of spray combustion with an advanced VOF method

    Science.gov (United States)

    Chen, Yen-Sen; Shang, Huan-Min; Shih, Ming-Hsin; Liaw, Paul

    1995-01-01

    This paper summarizes the technical development and validation of a multiphase computational fluid dynamics (CFD) numerical method using the volume-of-fluid (VOF) model and a Lagrangian tracking model which can be employed to analyze general multiphase flow problems with free surface mechanism. The gas-liquid interface mass, momentum and energy conservation relationships are modeled by continuum surface mechanisms. A new solution method is developed such that the present VOF model can be applied for all-speed flow regimes. The objectives of the present study are to develop and verify the fractional volume-of-fluid cell partitioning approach into a predictor-corrector algorithm and to demonstrate the effectiveness of the present approach by simulating benchmark problems including laminar impinging jets, shear coaxial jet atomization and shear coaxial spray combustion flows.

  15. Characterization of coaxial rocket injector sprays under high pressure environments

    Science.gov (United States)

    Sankar, S. V.; Wang, G.; Brena De La Rosa, A.; Rudoff, R. C.; Isakovic, A.; Bachalo, W. D.

    1992-01-01

    The effect of elevated environment pressures on the atomization characteristics of a single element, scaled-down, shear-coaxial rocket injector has been investigated. In this study, the shear coaxial injector was operated with water and air as simulants for conventionally used liquid oxygen and hydrogen gas, respectively. The experiments were conducted in a specially designed high pressure rig. A two-component PDPA/DSA system was used to study the spray characteristics at different chamber pressures ranging from atmospheric to 100 psig. The study showed an overall increase in the droplet sizes at higher chamber pressures. This phenomenon is attributed to a decrease in the secondary atomization effects at higher chamber pressures which, in turn, is directly related to a decrease in the shear experienced by the droplets as they move axially through the pressure chamber.

  16. Aerosol spray pyrolysis & solution phase synthesis of nanostructures

    Science.gov (United States)

    Zhang, Hongwang

    This dissertation focuses on the synthesis of nanomaterials by both solution phase and gas phase methods. By the solution phase method, we demonstrate the synthesis of Au/CdS binary hybrid nanoparticles and the Au-induced growth of CdS nanorods. At higher reaction temperature, extremely uniform CdS nanorods were obtained. The size of the Au seed nanoparticles has an important influence on the length and diameter of the nanorods. In addition, preparation of peanut-like FePt-CdS hybrid nanoparticles by spontaneous epitaxial nucleation and growth of CdS onto FePt-seed nanoparticles in high-temperature organic solution is reported. The FePt-CdS hybrid nanoparticles reported here are an example of a bifunctional nanomaterial that combines size-dependent magnetic and optical properties. In the gas phase method, a spray pyrolysis aerosol synthesis method was used to produce tellurium dioxide nanoparticles and zinc sulfide nanoparticles. Tellurite glasses (amorphous TeO2 based materials) have two useful optical properties, high refractive index and high optical nonlinearity, that make them attractive for a range of applications. In the work presented here, TeO2 nanoparticles were prepared by spray pyrolysis of an aqueous solution of telluric acid, Te(OH)6. This laboratory-scale process is capable of producing up to 80 mg/hr of amorphous TeO2-nanoparticles with primary particle diameters from 10 to 40 nm, and allows their synthesis in significant quantities from an inexpensive and environmentally friendly precursor. Furthermore, both Er3+ doped and Er3+ and Yb3+ co-doped tellurium dioxide nanoparticles were synthesized by spray pyrolysis of an aqueous mixture of telluric acid with erbium/ytterbium salts, which exhibit the infrared to green visible upconversion phenomena. ZnS nanoparticles (NPs) were prepared by spray pyrolysis using zinc diethyldithiocarbamate as a single-source precursor. The home-built scanning mobility particle spectrometer (SMPS) is a useful tool for

  17. CHARACTERIZATION OF DIESEL SPRAY IMAGES USING A SHAPE PROCESSING METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Cecile Petit

    2011-05-01

    Full Text Available In Diesel engines, a key element in achieving a clean and efficient combustion process is a proper fuel-air mixing, which is a consequence of the fuel spray development and fuel-air interaction inside the engine combustion chamber. The spray structure and behavior are classically described by the length (penetration and width (angle of the spray plume but these parameters do not give any clue on the geometrical injection center and on the spray symmetry. The purpose of this paper is to find out original tools to characterize the Diesel spray: the virtual spray origin is the geometrical injection center, which may (or may not coincide with the injector axis. Another interesting point is the description of the Diesel spray in terms of symmetry: the spray plume internal and external symmetry characterize the spray and the injector performance. Our approach is first to find out the virtual spray origin: after the image segmentation, the spray is coded with the Freeman code and with an original shape coding from which the moments are derived. The symmetry axes are then computed and the spray plumes are discarded (or not for the virtual spray origin computation, which is derived from a Voronoi diagram. The last step is the internal and external spray plume symmetry characterization thanks to correlation and mathematical distances.

  18. Comparision on dynamic behavior of diesel spray and rapeseed oil spray in diesel engine

    Science.gov (United States)

    Sapit, Azwan; Azahari Razali, Mohd; Faisal Hushim, Mohd; Jaat, Norrizam; Nizam Mohammad, Akmal; Khalid, Amir

    2017-04-01

    Fuel-air mixing is important process in diesel combustion. It significantly affects the combustion and emission of diesel engine. Biomass fuel has high viscosity and high distillation temperature and may negatively affect the fuel-air mixing process. Thus, study on the spray development and atomization of this type of fuel is important. This study investigates the atomization characteristics and droplet dynamic behaviors of diesel engine spray fuelled by rapeseed oil (RO) and comparison to diesel fuel (GO). Optical observation of RO spray was carried out using shadowgraph photography technique. Single nano-spark photography technique was used to study the characteristics of the spray while dual nano-spark shadowgraph technique was used to study the spray droplet behavior. Using in-house image processing algorithm, the images were processed and the boundary condition of each spray was also studied. The results show that RO has very poor atomization due to the high viscosity nature of the fuel when compared to GO. This is in agreement with the results from spray droplet dynamic behavior studies that shows due to the high viscosity, the RO spray droplets are large in size and travel downward, with very little influence of entrainment effect due to its large kinematic energy.

  19. EVALUATION OF CONVERGENT SPRAY TECHNOLOGYTM SPRAY PROCESS FOR ROOF COATING APPLICATION

    Science.gov (United States)

    The overall goal of this project was to demonstrate the feasibility of Convergent Spray TechnologyTM for the roofing industry. This was accomplished by producing an environmentally compliant coating utilizing recycled materials, a CSTTM spray process portable application cart, a...

  20. Mesoporous high surface area Ce0.9Gd0.1O1.95 synthesized by spray drying

    DEFF Research Database (Denmark)

    Lundberg, Mats; Wang, Hsiang-Jen; Blennow Tullmar, Peter;

    2011-01-01

    Mesoporous gadolinium doped cerium dioxide with high surface area was produced by spray drying using Pluronic 123 as surfactant. The powder, when calcined at 400 °C, had a BET surface area of 136 m2 g−1 and was polycrystalline as confirmed by XRD and TEM. XEDS confirmed Ce, Gd and O, as the only......, corresponding to the crystallite size calculated from XRD data. The similar size range of the mesopores and the observed crystallite size indicates that the porosity is partly formed from intergranular mesoporosity. Using the spray drying method of a surfactant assisted liquid precursor solution it can...

  1. Self-Pressurization and Spray Cooling Simulations of the Multipurpose Hydrogen Test Bed (MHTB) Ground-Based Experiment

    Science.gov (United States)

    Kartuzova, O.; Kassemi, M.; Agui, J.; Moder, J.

    2014-01-01

    This paper presents a CFD (computational fluid dynamics) model for simulating the self-pressurization of a large scale liquid hydrogen storage tank. In this model, the kinetics-based Schrage equation is used to account for the evaporative and condensing interfacial mass flows. Laminar and turbulent approaches to modeling natural convection in the tank and heat and mass transfer at the interface are compared. The flow, temperature, and interfacial mass fluxes predicted by these two approaches during tank self-pressurization are compared against each other. The ullage pressure and vapor temperature evolutions are also compared against experimental data obtained from the MHTB (Multipuprpose Hydrogen Test Bed) self-pressurization experiment. A CFD model for cooling cryogenic storage tanks by spraying cold liquid in the ullage is also presented. The Euler- Lagrange approach is utilized for tracking the spray droplets and for modeling interaction between the droplets and the continuous phase (ullage). The spray model is coupled with the VOF (volume of fluid) model by performing particle tracking in the ullage, removing particles from the ullage when they reach the interface, and then adding their contributions to the liquid. Droplet ullage heat and mass transfer are modeled. The flow, temperature, and interfacial mass flux predicted by the model are presented. The ullage pressure is compared with experimental data obtained from the MHTB spray bar mixing experiment. The results of the models with only droplet/ullage heat transfer and with heat and mass transfer between the droplets and ullage are compared.

  2. Study on Spray Characteristics and Spray Droplets Dynamic Behavior of Diesel Engine Fueled by Rapeseed Oil

    Directory of Open Access Journals (Sweden)

    Sapit Azwan

    2014-07-01

    Full Text Available Fuel-air mixing is important process in diesel combustion. It directly affects the combustion and emission of diesel engine. Biomass fuel needs great help to atomize because the fuel has high viscosity and high distillation temperature. This study investigates the atomization characteristics and droplet dynamic behaviors of diesel engine spray fueled by rapeseed oil (RO. Optical observation of RO spray was carried out using shadowgraph photography technique. Single nano-spark photography technique was used to study the characteristics of the rapeseed oil spray while dual nano-spark shadowgraph technique was used to study the spray droplet behavior. The results show that RO has very poor atomization due to the high viscosity nature of the fuel. This is in agreement with the results from spray droplet dynamic behavior studies that shows due to the high viscosity, the droplets are large in size and travel downward, with very little influence of entrainment effect due to its large kinematic energy.

  3. Latest Researches Advances of Plasma Spraying: From Splat to Coating Formation

    Science.gov (United States)

    Fauchais, P.; Vardelle, M.; Goutier, S.

    2016-12-01

    The plasma spray process with solid feedstock, mainly ceramics powders, studied since the sixties is now a mature technology. The plasma jet and particle in-flight characterizations are now well established. The use of computer-aided robot trajectory allows spraying on industrial parts with complex geometries. Works about splat formation have shown the importance of: the substrate preheating over the transition temperature to get rid of adsorbates and condensates, substrate chemistry, crystal structure and substrate temperature during the whole coating process. These studies showed that coating properties strongly depend on the splat formation and layering. The first part of this work deals with a summary of conventional plasma spraying key points. The second part presents the current knowledge in plasma spraying with liquid feedstock, technology developed for about two decades with suspensions of particles below micrometers or solutions of precursors that form particles a few micrometers sized through precipitation. Coatings are finely structured and even nanostructured with properties arousing the interest of researchers. However, the technology is by far more complex than the conventional ones. The main conclusions are that models should be developed further, plasma torches and injection setups adapted, and new measuring techniques to reliably characterize these small particles must be designed.

  4. Latest Researches Advances of Plasma Spraying: From Splat to Coating Formation

    Science.gov (United States)

    Fauchais, P.; Vardelle, M.; Goutier, S.

    2016-08-01

    The plasma spray process with solid feedstock, mainly ceramics powders, studied since the sixties is now a mature technology. The plasma jet and particle in-flight characterizations are now well established. The use of computer-aided robot trajectory allows spraying on industrial parts with complex geometries. Works about splat formation have shown the importance of: the substrate preheating over the transition temperature to get rid of adsorbates and condensates, substrate chemistry, crystal structure and substrate temperature during the whole coating process. These studies showed that coating properties strongly depend on the splat formation and layering. The first part of this work deals with a summary of conventional plasma spraying key points. The second part presents the current knowledge in plasma spraying with liquid feedstock, technology developed for about two decades with suspensions of particles below micrometers or solutions of precursors that form particles a few micrometers sized through precipitation. Coatings are finely structured and even nanostructured with properties arousing the interest of researchers. However, the technology is by far more complex than the conventional ones. The main conclusions are that models should be developed further, plasma torches and injection setups adapted, and new measuring techniques to reliably characterize these small particles must be designed.

  5. Flow visualization of a rocket injector spray using gelled propellant simulants

    Science.gov (United States)

    Green, James M.; Rapp, Douglas C.; Roncace, James

    1991-01-01

    A study was conducted at NASA-Lewis to compare the atomization characteristics of gelled and nongelled propellant simulants. A gelled propellant simulant composed of water, sodium hydroxide, and an acrylic acid polymer resin (as the gelling agent) was used to simulate the viscosity of an aluminum/PR-1 metallized fuel gel. Water was used as a comparison fluid to isolate the rheological effects of the water-gel and to simulate nongelled RP-1. The water-gel was injected through the central orifice of a triplet injector element and the central post of a coaxial injector element. Nitrogen gas flowed through the outer orifices of the triplet injector element and through the annulus of the coaxial injector element and atomized the gelled and nongelled liquids. Photographs of the water-gel spray patterns at different operating conditions were compared with images obtained using water and nitrogen. A laser light was used for illumination of the sprays. The results of the testing showed that the water sprays produced a finer and more uniform atomization than the water-gel sprays. Rheological analysis of the water-gel showed poor atomization caused by high viscosity of water-gel delaying the transition to turbulence.

  6. CFD simulation with enhancement factor of sulfur dioxide absorption in the spray scrubber

    Institute of Scientific and Technical Information of China (English)

    Xiang GAO; Wang HUO; Zhong-yang LUO; Ke-fa CEN

    2008-01-01

    A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented.Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model.A con-tinuous concentration change of H+ was solved by iterative coupling using Matlab,and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption.The calculations show that the enhancement factor exponentially grows with an increasing value ofpH and logarithmically decays with an increasing value of the driving force.To verify the accuracy of the model,experiments were also carried out,and the results suggest that the model,after combining the physical performance of the spray and the enhancement factor,can more precisely describe SO2 absorption in a spray scrubber.Furthermore,a commercial computational fluid dynamics(CFD)tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption.The results of numerical simulation can provide a basis for further design and optimization of the scrubber.

  7. Experimental study on spray characteristics of alternate jet fuels using Phase Doppler Anemometry

    Science.gov (United States)

    Kannaiyan, Kumaran; Sadr, Reza

    2013-11-01

    Gas-to-Liquid (GTL) fuels have gained global attention due to their cleaner combustion characteristics. The chemical and physical properties of GTL jet fuels are different from conventional jet fuels owing to the difference in their production methodology. It is important to study the spray characteristics of GTL jet fuels as the change of physical properties can affect atomization, mixing, evaporation and combustion process, ultimately affecting emission process. In this work, spray characteristics of two GTL synthetic jet fuels are studied using a pressure-swirl nozzle at different injection pressures and atmospheric ambient condition. Phase Doppler Anemometry (PDA) measurements of droplet size and velocity are compared with those of regular Jet A-1 fuel at several axial and radial locations downstream of the nozzle exit. Experimental results show that although the GTL fuels have different physical properties such as viscosity, density, and surface tension, among each other the resultant change in the spray characteristics is insignificant. Furthermore, the presented results show that GTL fuel spray characteristics exhibit close similarity to those of Jet A-1 fuel. Funded by Qatar Science and Technology Park.

  8. Containment atmosphere response to external sprays

    Energy Technology Data Exchange (ETDEWEB)

    Green, J.; Almenas, K. [Univ. of Maryland, College Park, MD (United States)

    1995-09-01

    The application of external sprays to a containment steel shell can be an effective energy removal method and has been proposed in the passive AP-600 design. Reduction of the steel shell temperature in contact with the containment atmosphere enhances both heat and mass transfer driving forces. Large scale experimental data in this area is scarce, therefore the measurements obtained from the E series tests conducted at the German HDR facility deserve special attention. These long term tests simulated various severe accident conditions, including external spraying of the hemispherical steel shell. This investigation focuses upon the integral response of the HDR containment atmosphere during spray periods and upon methods by which lumped parameter system codes, like CONTAIN, model the underlying condensation phenomena. Increases in spray water flowrates above a minimum value were ineffective at improving containment pressure reduction since the limiting resistance for energy transfer lies in the noncondensable-vapor boundary layer at the inner condensing surface. The spray created an unstable condition by cooling the upper layers of a heated atmosphere and thus inducing global natural circulation flows in the facility and subsequently, abrupt changes in lighter-than-air noncondensable (J{sub 2}/He) concentrations. Modeling results using the CONTAIN code are outlined and code limitations are delineated.

  9. Microalgal cell disruption via ultrasonic nozzle spraying.

    Science.gov (United States)

    Wang, M; Yuan, W

    2015-01-01

    The objective of this study was to understand the effect of operating parameters, including ultrasound amplitude, spraying pressure, nozzle orifice diameter, and initial cell concentration on microalgal cell disruption and lipid extraction in an ultrasonic nozzle spraying system (UNSS). Two algal species including Scenedesmus dimorphus and Nannochloropsis oculata were evaluated. Experimental results demonstrated that the UNSS was effective in the disruption of microalgal cells indicated by significant changes in cell concentration and Nile red-stained lipid fluorescence density between all treatments and the control. It was found that increasing ultrasound amplitude generally enhanced cell disruption and lipid recovery although excessive input energy was not necessary for best results. The effect of spraying pressure and nozzle orifice diameter on cell disruption and lipid recovery was believed to be dependent on the competition between ultrasound-induced cavitation and spraying-generated shear forces. Optimal cell disruption was not always achieved at the highest spraying pressure or biggest nozzle orifice diameter; instead, they appeared at moderate levels depending on the algal strain and specific settings. Increasing initial algal cell concentration significantly reduced cell disruption efficiency. In all UNSS treatments, the effectiveness of cell disruption and lipid recovery was found to be dependent on the algal species treated.

  10. Survival of bifidobacteria after spray-drying.

    Science.gov (United States)

    Lian, Wen-Chian; Hsiao, Hung-Chi; Chou, Cheng-Chun

    2002-03-25

    To investigate the survival of bifidobacteria after spray-drying, Bifidobacterium infantis CCRC 14633, B. infantis CCRC 14661, B. longum ATCC 15708, B. longum CCRC 14634 and B. longum B6 were first spray-dried with different carrier media including 10% (w/w) gelatin, gum arabic and soluble starch. B. infantis CCRC 14633 and B. longum were also determined in skim milk. It was found that survival of bifidobacteria after spray-drying varied with strains and is highly dependent on the carriers used. Among the test organisms, B. longum B6 exhibited the least sensitivity to spray-drying and showed the highest survival of ca. 82.6% after drying with skim milk. Comparisons of the effect of carrier concentrations revealed that spray-drying at 10% (w/w) gelatin, gum arabic or soluble starch resulted in the highest survival of bifidobacteria. In addition, among the various outlet-air temperatures tested, bifidobacteria showed the highest survival after drying at 50 degrees C. Elevation of outlet-air temperature caused increased inactivation of bifidobacteria. However, the inactivation caused by increased outlet-air temperature varied with the carrier used, with the greatest reduction observed using soluble starch and the least with skim milk.

  11. Computer modelling of the meteorological and spraying parameters that influence the aerial dispersion of agrochemical sprays

    Science.gov (United States)

    Mokeba, M. L.; Salt, D. W.; Lee, B. E.; Ford, M. G.

    An insight into the nature of prevailing meteorological conditions and the manner in which they interact with spraying parameters is an important prerequisite in the analysis of the dynamics of agrochemical sprays. Usually, when these sprays are projected from hydraulic nozzles, their initial velocity is greater than that of the ambient wind speed. The flowfield therefore experiences changes in speed and direction which are felt upstream as well as downstream of the spray droplets. The pattern of the droplet flow, i.e. the shape of the streamlines marking typical trajectories, will be determined by a balance of viscous forces related to wind speed, inertial forces resulting from the acceleration of the airstream and pressure forces which can be viewed in terms of the drag forces exerted on the spray droplets themselves. At a certain distance in the ensuing motion, when the initial velocity of the spray droplets has decreased sufficiently for there to be no acceleration, their trajectories will be controlled entirely by the random effects of turbulence. These two transport processes in the atmosphere can be modelled mathematically using computers. This paper presents a model that considers the velocity of spray droplets to consist of a ballistic velocity component superimposed by a random-walk velocity component. The model is used to study the influence of meteorological and spraying parameters on the three-dimensional dynamics of spray droplets projected in specified directions in neutral and unstable weather conditions. The ballistic and random-walk velocity components are scaled by factors of (1-ξ) and ξ respectively, where ξ is the ratio of the sedimentation velocity and the relative velocity between the spray droplets and the surrounding airstream. This ratio increases progressively as the initial velocity of the spray droplet decreases with air resistance and attains a maximum when the sedimentation velocity has been reached. As soon as this occurs, the

  12. Microstructure evolution of cold-sprayed coating during deposition and through post-spraying heat treatment

    Institute of Scientific and Technical Information of China (English)

    LI Chang-jiu; LI Wen-ya

    2004-01-01

    The microstructural features of cold-sprayed coatings were investigated using Cu, Ti and Zn feedstocks by optical microscopy, scanning electron microscopy and transmission electron microscopy to reveal the microstructure evolution mechanisms in cold spray. Four typical effects including tamping, refinement, impact-induced fusion and annealing were examined on microstrueture. It is found that the microstructure of cold spray coating is remarkably influenced by spray materials. Ti coatings consist of evident porous layer and Cu coatings present a limited porous layer only near the surface. It is clear that the successive tamping effect and dynamic refinement of grains significantly influence the microstructure evolution of cold-sprayed coating. The tamping effect leads to the densification of porous coating layer gradually and the refinement effect leads to the formation of fine microstructure. It is considered that the large difference in the formation of porous layer is attributed to the dynamic impact pressure and hardenability of materials. It is also found that the impact-induced fusion during deposition of Zn coating can also modify the interfacial microstructure between particles in cold spray coating. Moreover, the nanocrystalline phase can be formed at the interfaces among particles resulting from the localized melting of the interfaces and tamping effect. Furthermore, the annealing treatment can modify the microstructure and property of a cold-sprayed coating.

  13. Micrometeorological measurements during the Blackmo 88 spray trials

    Science.gov (United States)

    D. E. Anderson; D. R. Miller; Y. S. Wang; W. E. Yendol; M. L. McManus

    1991-01-01

    Instrumentation was arrayed on a 120 foot tower to detail the local atmospheric conditions during the Blackmo 88 spray experiment. Measurements were continuous for 30 minute periods encompassing each spray pass.

  14. Water jet/spray measurement analysis

    Science.gov (United States)

    Lala, G. G.

    1986-01-01

    The objective of this study was to provide analysis of data obtained under a previous contract entitled Characterization of Drop Spectra from High Volume Flow Water Jets. Measurements of drop spectra were obtained in the spray resulting from the breakup of high volume flow water jets from a variety of nozzle types. The drop spectra measurements were obtained from two drop spectrometers covering a range from 10 microns to 12 millimeters diameter. The task addressed was to select representative spectra from the individual tests and provide analyses in both numerical and graphical formats as outlined in the proposal. The intended application of these results is an evaluation of the feasibility of fog clearing by high volume water sprays. During the tests, a fog event occurred making it possible to test the concept of fog clearing. Visual range data and fog drop spectra were analyzed, with particular emphasis placed on the modification of these parameters due to the water spray.

  15. Examining properties of arc sprayed nanostructured coatings

    Directory of Open Access Journals (Sweden)

    A. Czupryński

    2016-04-01

    Full Text Available The article presents the results of examining properties of arc sprayed coating obtained with nano-alloy on the iron matrix with a high amount of fine carbide precipitates sprayed on non-alloyed steel plates intended for high temperature operation. Powder metal cored wire EnDOtec DO*390N 1,6 mm diameter, was used to produce, dense, very high abrasion and erosion resistant coatings approx. 1,0 mm thick. Nano-material coatings characterization was done to determine abrasion resistance, erosion resistance, adhesion strength, hardness as well as metallographic examinations. Results have proved high properties of arc sprayed nano-material coatings and have shown promising industrial applications.

  16. Spray Drying of Mosambi Juice in Lab

    Science.gov (United States)

    Singh, S. V.; Verma, A.

    2014-01-01

    The studies on spray drying of mosambi juice were carried out with Laboratory spray dryer set-up (LSD-48 MINI SPRAY DRYER-JISL). Inlet and outlet air temperature and maltodextrin (drying agent) concentration was taken as variable parameters. Experiments were conducted by using 110 °C to 140 °C inlet air temperature, 60 °C to 70 °C outlet air temperature and 5-7 % maltodextrin concentration. The free flow powder of mosambi juice was obtained with 7 % maltodextrin at 140 °C inlet air temperature and 60 °C outlet air temperature. Fresh and reconstituted juices were evaluated for vitamin C, titrable acidity and sensory characteristics. The reconstituted juice was found slightly acceptable by taste panel.

  17. Silver nasal sprays: misleading Internet marketing.

    Science.gov (United States)

    Gaslin, Michael T; Rubin, Cory; Pribitkin, Edmund A

    2008-04-01

    Long-term use of silver-containing products is associated with a permanent bluish-gray discoloration of the skin known as argyria, but they remain widely available despite several measures by the FDA to regulate them. Several recent case reports have described the occurrence of argyria as a result of using these "natural" products. We used the five most common Internet search engines to find Web sites providing information on silver-containing nasal sprays. Of 49 Web sites analyzed, only 2 (4%) mentioned argyria as a possible complication, although 30 (61%) did caution against long-term use. Eight sites (16%) made specific claims about the health benefits of the product. All 49 sites (100%) provided direct or indirect links to buy silver-containing nasal sprays. We conclude that information about silver-containing nasal sprays on the Internet is misleading and inaccurate. Therefore, otolaryngologists should be aware of the misinformation their patients may be receiving about these products.

  18. Fullerene monolayer formation by spray coating.

    Science.gov (United States)

    Cervenka, J; Flipse, C F J

    2010-02-10

    Many large molecular complexes are limited in thin film applications by their insufficient thermal stability, which excludes deposition via commonly used vapour phase deposition methods. Here we demonstrate an alternative way of monolayer formation of large molecules by a simple spray coating method under ambient conditions. This technique has been successfully applied on C(60) dissolved in toluene and carbon disulfide. Monolayer thick C(60) films have been formed on graphite and gold surfaces at particular deposition parameters, as confirmed by atomic force and scanning tunnelling microscopies. Structural and electronic properties of spray coated C(60) films on Au(111) have been found comparable to thermally evaporated C(60). We attribute the monolayer formation in spray coating to a crystallization process mediated by an ultrathin solution film on a sample surface.

  19. Direct quantitative analysis of nicotine alkaloids from biofluid samples using paper spray mass spectrometry.

    Science.gov (United States)

    Wang, He; Ren, Yue; McLuckey, Morgan N; Manicke, Nicholas E; Park, Jonghyuck; Zheng, Lingxing; Shi, Riyi; Cooks, R Graham; Ouyang, Zheng

    2013-12-03

    The determination of tobacco derived nicotine alkaloids in biofluid samples is of great importance to testing for tobacco use, tobacco cessation treatment, and studies on exposure to secondhand smoke. Paper spray mass spectrometry (MS) has been adapted for direct, quantitative analysis of tobacco alkaloids from biofluid samples, such as blood, urine, and saliva in liquid and dried form. Limits of quantitation as low as several nanograms per milliliter were obtained for nicotine, cotinine, trans-3'-hydroxycotinine, and anabasine. Direct analysis of fresh blood samples has also been achieved with improved sensitivity using print paper substrates of high density. Quantitation of the cotinine in the blood of a rat was performed with both direct analysis using paper spray and a traditional analysis protocol using liquid chromatography MS. Comparable results were obtained and the precision of the two methods was similar. The paper spray MS method is rapid and shows potential for significantly improved analytical efficiency in clinical laboratories as well as for point-of-care tobacco use assessment.

  20. Development of Expert Controller for Plasma Spraying Process

    Institute of Scientific and Technical Information of China (English)

    LIChun-xu; CHENKe-xuan; LIHe-qi; LIDe-wu

    2004-01-01

    Aiming at the plasma spraying process control, the control system model is developed on the basis of analyzing control parameters and coating properties and their correlation, and the corresponding control method and regulations are also given. With the developed expert controller for plasma spraying process, stable spraying can be realized using ordinary spraying powder and the coating of compaction, homogeneity and high bonding strength can be obtained.

  1. Spray drying technique: II. Current applications in pharmaceutical technology.

    Science.gov (United States)

    Sollohub, Krzysztof; Cal, Krzysztof

    2010-02-01

    This review presents current applications of spray drying in pharmaceutical technology. The topics discussed include the obtention of excipients and cospray dried composites, methods for increasing the aqueous solubility and bioavailability of active substances, and modified release profiles from spray-dried particles. This review also describes the use of the spray drying technique in the context of biological therapies, such as the spray drying of proteins, inhalable powders, and viable organisms, and the modification of the physical properties of dry plant extracts.

  2. Modeling Droplet Heat and Mass Transfer during Spray Bar Pressure Control of the Multipurpose Hydrogen Test Bed (MHTB) Tank in Normal Gravity

    Science.gov (United States)

    Kartuzova, O.; Kassemi, M.

    2016-01-01

    A CFD model for simulating pressure control in cryogenic storage tanks through the injection of a subcooled liquid into the ullage is presented and applied to the 1g MHTB spray bar cooling experiments. An Eulerian-Lagrangian approach is utilized to track the spray droplets and capture the interaction between the discrete droplets and the continuous ullage phase. The spray model is coupled with the VOF model by performing particle tracking in the ullage, removing particles from the ullage when they reach the interface, and then adding their contributions to the liquid. A new model for calculating the droplet-ullage heat and mass transfer is developed. In this model, a droplet is allowed to warm up to the saturation temperature corresponding to the ullage vapor pressure, after which it evaporates while remaining at the saturation temperature. The droplet model is validated against the results of the MHTB spray-bar cooling experiments with 50% and 90% tank fill ratios. The predictions of the present T-sat based model are compared with those of a previously developed kinetic-based droplet mass transfer model. The predictions of the two models regarding the evolving tank pressure and temperature distributions, as well as the droplets' trajectories and temperatures, are examined and compared in detail. Finally, the ullage pressure and local vapor and liquid temperature evolutions are validated against the corresponding data provided by the MHTB spray bar mixing experiment.

  3. Dynamic residual stress in thermal sprayed coatings

    Institute of Scientific and Technical Information of China (English)

    Wang Zhiping; Yang Yuanyuan

    2005-01-01

    With the modified Almen method, the forming and development process of residual stress in a thermal sprayed coating has been obtained. The test results identify that the residual stress in a coating is depend on coating material properties, technique and coating thickness. The paper pays much attention to the hysteresis between the coating temperature and residual stress in the coating or between the applied stress and the strain of the coating, and confirms that the fact is resulted from the"Gas Fix" character of a thermal sprayed coating.

  4. Numerical Simulation and Experimental Characterization of a Binary Aluminum Alloy Spray - Application to the Spray Rolling Process

    Energy Technology Data Exchange (ETDEWEB)

    S. B. Johnson; J.-P. Delplanque; Y. Lin; Y. Zhou; E. J. Lavernia; K. M. McHugh

    2005-02-01

    A stochastic, droplet-resolved model has been developed to describe the behavior of a binary aluminum alloy spray during the spray-rolling process. In this process, a molten aluminum alloy is atomized and the resulting spray is depostied on the rolls of a twin-roll caster to produce aluminum strip. The one-way coupled spray model allows the prediction of spray characteristics such as enthalph and solid fraction, and their distribution between the nozzle and the depostion surface. This paper outlines the model development and compares the predicted spray dynamics to PDI measurements performed in a controlled configuration. Predicted and measured droplet velocity and size distributions are presented for two points along the spray centerline along with predicted spray averaged specific enthalph and solid fraction curves.

  5. Experimental Research on Flash Boiling Spray of Dimethyl Ether

    Institute of Scientific and Technical Information of China (English)

    Peng Zhang

    2014-01-01

    The high-speed digital imaging technique is applied to observe the developing process of flash boiling spray of dimethyl ether at low ambient pressure, and the effects of nozzle opening pressure and nozzle hole diameter on the spray shape, spray tip penetration and spray angle during the injection are investigated. The experimental results show that the time when the vortex ring structure of flash boiling spray forms and its developing process are determined by the combined action of the bubble growth and breakup in the spray and the air drag on the leading end of spray;with the enhancement of nozzle opening pressure, the spray tip penetration increases and the spray angle decreases. The influence of nozzle hole diameter on the spray tip penetration is relatively complicated, the spray tip penetration is longer with a smaller nozzle hole diameter at the early stage of injection, while the situation is just opposite at the later stage of injection. This paper establishes that the variation of spray angle is consistent with that of nozzle hole diameter.

  6. Alignment Fixtures For Vacuum-Plasma-Spray Gun

    Science.gov (United States)

    Woodford, William H.; Mckechnie, Timothy N.; Power, Christopher A.; Daniel, Ronald L., Jr.

    1993-01-01

    Fixtures for alignment of vacuum-plasma-spray guns built. Each fixture designed to fit specific gun and holds small, battery-powered laser on centerline of gun. Laser beam projects small red dot where centerline intersects surface of workpiece to be sprayed. After laser beam positioned on surface of workpiece, fixture removed from gun and spraying proceeds.

  7. Experimental research on flash boiling spray of dimethyl ether

    Science.gov (United States)

    Zhang, Peng

    2014-12-01

    The high-speed digital imaging technique is applied to observe the developing process of flash boiling spray of dimethyl ether at low ambient pressure, and the effects of nozzle opening pressure and nozzle hole diameter on the spray shape, spray tip penetration and spray angle during the injection are investigated. The experimental results show that the time when the vortex ring structure of flash boiling spray forms and its developing process are determined by the combined action of the bubble growth and breakup in the spray and the air drag on the leading end of spray; with the enhancement of nozzle opening pressure, the spray tip penetration increases and the spray angle decreases. The influence of nozzle hole diameter on the spray tip penetration is relatively complicated, the spray tip penetration is longer with a smaller nozzle hole diameter at the early stage of injection, while the situation is just opposite at the later stage of injection. This paper establishes that the variation of spray angle is consistent with that of nozzle hole diameter.

  8. Review of the MDF-LSA 100 Spray Decontamination System

    Science.gov (United States)

    2011-12-01

    UNCLASSIFIED Review of the MDF -LSA 100 Spray Decontamination System Rodi Sferopoulos Human Protection and Performance Division...and performance of the Modec Decontamination Foam ( MDF )-LSA 100 Spray Decontamination System as well as information regarding the decontamination...RELEASE UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED Review of the MDF -LSA 100 Spray Decontamination System Executive Summary DSTO were

  9. 9 CFR 590.542 - Spray process drying operations.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Spray process drying operations. 590..., Processing, and Facility Requirements § 590.542 Spray process drying operations. (a) The drying room shall be... interrupted. (1) Spray nozzles, orifices, cores, or whizzers shall be cleaned immediately after cessation...

  10. Superomniphobic and easily repairable coatings on copper substrates based on simple immersion or spray processes.

    Science.gov (United States)

    Rangel, Thomaz C; Michels, Alexandre F; Horowitz, Flávio; Weibel, Daniel E

    2015-03-24

    Textures that resemble typical fern or bracken plant species (dendrite structures) were fabricated for liquid repellency by dipping copper substrates in a single-step process in solutions containing AgNO3 or by a simple spray liquid application. Superhydrophobic surfaces were produced using a solution containing AgNO3 and trimethoxypropylsilane (TMPSi), and superomniphobic surfaces were produced by a two-step procedure, immersing the copper substrate in a AgNO3 solution and, after that, in a solution containing 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES). The simple functionalization processes can also be used when the superomniphobic surfaces were destroyed by mechanical stress. By immersion of the wrecked surfaces in the above solutions or by the spray method and soft heating, the copper substrates could be easily repaired, regenerating the surfaces' superrepellency to liquids. The micro- and nanoroughness structures generated on copper surfaces by the deposition of silver dendrites functionalized with TMPSi presented apparent contact angles greater than 150° with a contact angle hysteresis lower than 10° when water was used as the test liquid. To avoid total wettability with very low surface tension liquids, such as rapeseed oil and hexadecane, a thin perfluorinated coating of poly(tetrafluoroethylene) (PTFE), produced by physical vapor deposition, was used. A more efficient perfluorinated coating was obtained when PFDTES was used. The superomniphobic surfaces produced apparent contact angles above 150° with all of the tested liquids, including hexadecane, although the contact angle hysteresis with this liquid was above 10°. The coupling of dendritic structures with TMPSi/PTFE or directly by PFDTES coatings was responsible for the superrepellency of the as-prepared surfaces. These simple, fast, and reliable procedures allow the large area, and cost-effective scale fabrication of superrepellent surfaces on copper substrates for various industrial

  11. Nanosized films based on multicharged small molecules and oppositely charged polyelectrolytes obtained by simultaneous spray coating of interacting species.

    Science.gov (United States)

    Lefort, Mathias; Jierry, Loïc; Boulmedais, Fouzia; Benmlih, Karim; Lavalle, Philippe; Senger, Bernard; Voegel, Jean-Claude; Hemmerlé, Joseph; Ponche, Arnaud; Schaaf, Pierre

    2013-11-26

    Simultaneous spraying of polyelectrolytes and small multicharged molecules of opposite charges onto a vertical substrate leads to continuous buildups of organic films. Here, we investigate the rules governing the buildup of two such systems: poly(allylamine hydrochloride)/sodium citrate (PAH/citrate) and PAH/sulfated α-cyclodextrin (PAH/CD-S). Special attention is paid to the film growth rate as a function of the spraying rate ratio of the two constituents. This parameter was varied by increasing the spraying rate of one of the constituents while maintaining constant that of the other. For PAH/CD-S systems, whatever the constituent (PAH or CD-S) whose spraying rate was kept fixed, the film growth rate first increases and passes through a maximum before decreasing when the spraying rate of the other constituent is increased. For PAH/citrate, the film growth rate reaches a plateau value when the spraying rate of citrate is increased while that of PAH is maintained constant, whereas when the spraying rate of citrate is maintained constant and that of PAH is increased, a behavior similar to that of PAH/CD-S is observed. The composition of PAH/CD-S sprayed films determined by X-ray photoelectron spectroscopy is independent of the spraying rate ratio of the two constituents and corresponds to one allylamine for one sulfate group. For PAH/citrate, by increasing the PAH/citrate spraying rate ratio, the carboxylic/nitrogen ratio in the film increases and tends to 1. There is thus always a deficit of carboxylic groups (COO(-) + COOH) with respect to amines (NH2 + NH3(+)). Yet, the ratio (COO(-)/NH3(+)) is always close to 1, ensuring exact charge compensation. The film morphology determined by atomic force microscopy is granular for PAH/CD-S and is smooth and liquid-like for PAH/citrate. A model based on strong (respectively weak) interactions between PAH and CD-S (respectively citrate) is proposed to explain these features.

  12. High Order Moment Model for Polydisperse Evaporating Sprays Towards Interfacial Geometry

    CERN Document Server

    Essadki, Mohamed; Laurent, Frédérique; Massot, Marc

    2016-01-01

    In this paper we propose a new Eulerian modeling and related accurate and robust numerical methods, describing polydisperse evaporating sprays, based on high order moment methods in size. The main novelty of this model is its capacity to describe some geometrical variables of the droplet-gas interface, by analogy with the liquid-gas interface in interfacial flows. For this purpose, we use fractional size-moments, where the size variable is taken as the droplet surface. In order to evaluate the evaporation of the polydisperse spray, we use a smooth reconstruction which maximizes the Shannon entropy. However, the use of fractional moments introduces some theoretical and numerical difficulties, which need to be tackled. First, relying on a study of the moment space, we extend the Maximum Entropy (ME) reconstruction of the size distribution to the case of fractional moments. Then, we propose a new accurate and realizable algorithm to solve the moment evolution due to evaporation, which preserves the structure of ...

  13. Synthesis of MgO Nanoparticles by Solvent Mixed Spray Pyrolysis Technique for Optical Investigation

    Directory of Open Access Journals (Sweden)

    K. R. Nemade

    2014-01-01

    Full Text Available Solvent mixed spray pyrolysis technique has attracted a global interest in the synthesis of nanomaterials since reactions can be run in liquid state without further heating. Magnesium oxide (MgO is a category of the practical semiconductor metal oxides, which is extensively used as catalyst and optical material. In the present study, MgO nanoparticles were successfully synthesized using a solvent mixed spray pyrolysis. The X-ray diffraction pattern confirmed the formation of MgO phase with an excellent crystalline structure. Debye-Scherrer equation is used for the determination of particle size, which was found to be 9.2 nm. Tunneling electron microscope analysis indicated that the as-synthesized particles are nanoparticles with an average particle size of 9 nm. Meanwhile, the ultraviolet-visible spectroscopy of the resulting product was evaluated to study its optical property via measurement of the band gap energy value.

  14. Functional properties and stability of spray-dried pigments from Bordo grape (Vitis labrusca) winemaking pomace.

    Science.gov (United States)

    Souza, Volnei Brito de; Fujita, Alice; Thomazini, Marcelo; da Silva, Edson Roberto; Lucon, João Francisco; Genovese, Maria Inés; Favaro-Trindade, Carmen Sílvia

    2014-12-01

    The stability of anthocyanin and phenolic compounds, the antioxidant capacity, the antimicrobial activity and the capacity to inhibit arginase from Leishmania were evaluated in spray-dried powders from Bordo grape winemaking pomace extract. The pigments were produced using maltodextrin as the carrier agent at concentrations varying from 10% to 30% and air entrance temperatures varying from 130 to 170°C. A sample of freeze-dried extract without the carrier was also evaluated. The anthocyanins in the spray-dried samples showed good stability during storage, better than the freeze-dried and liquid extracts. The samples were capable of inhibiting the growth of Staphylococcus aureus and Listeria monocytogenes and showed high inhibitory capacity against the enzyme arginase from Leishmania. These results provide evidence that Bordo grapes from the winemaking process have the potential to be used as natural pigments with functional properties.

  15. Quality by Design approach to spray drying processing of crystalline nanosuspensions.

    Science.gov (United States)

    Kumar, Sumit; Gokhale, Rajeev; Burgess, Diane J

    2014-04-10

    Quality by Design (QbD) principles were explored to understand spray drying process for the conversion of liquid nanosuspensions into solid nano-crystalline dry powders using indomethacin as a model drug. The effects of critical process variables: inlet temperature, flow and aspiration rates on critical quality attributes (CQAs): particle size, moisture content, percent yield and crystallinity were investigated employing a full factorial design. A central cubic design was employed to generate the response surface for particle size and percent yield. Multiple linear regression analysis and ANOVA were employed to identify and estimate the effect of critical parameters, establish their relationship with CQAs, create design space and model the spray drying process. Inlet temperature was identified as the only significant factor (p value dried nano-crystalline powders. Aspiration and flow rates were identified as significant factors affecting yield (p value dried at higher inlet temperatures had lower moisture compared to those dried at lower inlet temperatures.

  16. Compositional dependence of microstructure and tribological properties of plasma sprayed Fe-based metallic glass coatings

    Institute of Scientific and Technical Information of China (English)

    YANG Qin; LI Ran; LIU ZengQian; SHI MinJie; LUO XueKun; ZHANG Tao

    2012-01-01

    Gas-atomized powders of three Fe-based glass-forming alloys were sprayed on mild steel substrates by atmospheric plasma spaying using the same spaying parameters.Microstructures,thermal stabilities and tribological properties of the sprayed coatings were analyzed.The coating performances showed a strong dependence on the intrinsic characters of the compositions,i,e.,glass-forming ability (GFA) and supercooled liquid region (ΔTx).The coatings tended to exhibit higher amorphous phase fraction for the composition with higher GFA and lower porosity for that with larger ΔTx.All the coatings exhibited superior wear resistance compared with the substrate.Higher wear resistance could be obtained in coatings with higher amorphous phase fraction,i.e.higher GFA of the composition.This study has important implications for composition selecting and optimizing in the fabrication of metallic glass coatings.

  17. Preparation of sustained-release coated particles by novel microencapsulation method using three-fluid nozzle spray drying technique.

    Science.gov (United States)

    Kondo, Keita; Niwa, Toshiyuki; Danjo, Kazumi

    2014-01-23

    We prepared sustained-release microcapsules using a three-fluid nozzle (3N) spray drying technique. The 3N has a unique, three-layered concentric structure composed of inner and outer liquid nozzles, and an outermost gas nozzle. Composite particles were prepared by spraying a drug suspension and an ethylcellulose solution via the inner and outer nozzles, respectively, and mixed at the nozzle tip (3N-PostMix). 3N-PostMix particles exhibited a corrugated surface and similar contact angles as ethylcellulose bulk, thus suggesting encapsulation with ethylcellulose, resulting in the achievement of sustained release. To investigate the microencapsulation process via this approach and its usability, methods through which the suspension and solution were sprayed separately via two of the four-fluid nozzle (4N) (4N-PostMix) and a mixture of the suspension and solution was sprayed via 3N (3N-PreMix) were used as references. It was found that 3N can obtain smaller particles than 4N. The results for contact angle and drug release corresponded, thus suggesting that 3N-PostMix particles are more effectively coated by ethylcellulose, and can achieve higher-level controlled release than 4N-PostMix particles, while 3N-PreMix particles are not encapsulated with pure ethylcellulose, leading to rapid release. This study demonstrated that the 3N spray drying technique is useful as a novel microencapsulation method.

  18. Numerical Simulation of the Effect of 3D Needle Movement on Cavitation and Spray Formation in a Diesel Injector

    Science.gov (United States)

    Mandumpala Devassy, B.; Edelbauer, W.; Greif, D.

    2015-12-01

    Cavitation and its effect on spray formation and its dispersion play a crucial role in proper engine combustion and controlled emission. This study focuses on these effects in a typical common rail 6-hole diesel injector accounting for 3D needle movement and flow compressibility effects. Coupled numerical simulations using 1D and 3D CFD codes are used for this investigation. Previous studies in this direction have already presented a detailed structure of the adopted methodology. Compared to the previous analysis, the present study investigates the effect of 3D needle movement and cavitation on the spray formation for pilot and main injection events for a typical diesel engine operating point. The present setup performs a 3D compressible multiphase simulation coupled with a standalone 1D high pressure flow simulation. The simulation proceeds by the mutual communication between 1D and 3D solvers. In this work a typical common rail injector with a mini-sac nozzle is studied. The lateral and radial movement of the needle and its effect on the cavitation generation and the subsequent spray penetration are analyzed. The result indicates the effect of compressibility of the liquid on damping the needle forces, and also the difference in the spray penetration levels due to the asymmetrical flow field. Therefore, this work intends to provide an efficient and user-friendly engineering tool for simulating a complete fuel injector including spray propagation.

  19. Corrosion Behavior of Cold Sprayed Titanium Coatings and Free Standing Deposits

    Science.gov (United States)

    Hussain, T.; McCartney, D. G.; Shipway, P. H.; Marrocco, T.

    2011-01-01

    Cold gas dynamic spraying can be used to deposit oxygen-sensitive materials, such as titanium, without significant chemical degradation of the powder. The process is thus believed to have potential for the deposition of corrosion-resistant barrier coatings. However, to be effective, a barrier coating must not allow ingress of a corrosive liquid and hence must not have interconnected porosity. This study investigated the effects of porosity on the corrosion behavior of cold sprayed titanium coatings onto carbon steel and also of free standing deposits. For comparative purposes, a set of free standing deposits was also vacuum heat-treated to further decrease porosity levels below those in the as-sprayed condition. Microstructures were examined by optical and scanning electron microscopy. Mercury intrusion porosimetry (MIP) was used to characterize the interconnected porosity over a size range of micrometers to nanometers. Open circuit potential (OCP) measurements and potentiodynamic polarization scans in 3.5 wt.% NaCl were used to evaluate the corrosion performance. The MIP results showed that in cold sprayed deposits a significant proportion of the porosity was sub-micron and so could not be reliably measured by optical microscope based image analysis. In the case of free standing deposits, a reduction in interconnected porosity resulted in a lower corrosion current density, a lower passive current density, and an increase in OCP closer to that of bulk titanium. For the lowest porosity level, ~1.8% achieved following vacuum heat treatment, the passive current density was identical to that of bulk titanium. However, electrochemical measurements of the coatings showed significant substrate influence when the interconnected porosity of the coating was 11.3 vol.% but a decreased substrate influence with a porosity level of 5.9 vol.%. In the latter case, the OCP was still around 250 mV below that of bulk Ti. Salt spray tests confirmed these electrochemical findings and

  20. Control of particle morphology in the spray drying of colloidal suspensions.

    Science.gov (United States)

    Lintingre, E; Lequeux, F; Talini, L; Tsapis, N

    2016-09-28

    Powders of nanoparticles are volatile, i.e. easily disperse in air, which makes their handling difficult. Granulation of nanoparticle powders provides a solution to that issue, and it is generally performed by spray drying the nanoparticles that have been suspended in a liquid. Spray drying of a colloidal suspension consists of atomising the suspension into droplets by a fast flowing and hot gas. Once the droplets dried, the resulting dry grains/microparticles can be used in a wide range of applications - food, pharmaceutics, fillers, ceramics, etc. It is well known that the grains resulting from spray-drying may be spherical but may also exhibit other diverse morphologies. Although different influencing parameters have been identified, no clear overview can be found in the literature for the driving mechanisms of grain shaping. In the present work, we review the assumptions made in the literature to explain the different morphologies. We analyse the orders of magnitude of the different effects at stake and show that the grain shape does not result from a hydrodynamic instability but is determined by the drying stage. However, we emphasize that neither the drying time nor the associated Péclet number are critical parameters for the determination of shape morphology. In light of those results, we also review and discuss the single droplet experiments developed to mimic spray drying. Generalising our previous works, we further analyse how the control of morphology can be achieved by tuning the colloidal interactions in the suspension. We detail the model we have developed that relates the colloidal interaction potential to a critical pressure exerted by the solvent as it flows, and we provide a quantitative prediction of the grain shape. Finally, we offer perspectives with regard to spray drying of systems such as molecular solutions, widely performed in e.g. the pharmaceutical industry.

  1. Determination of parameters for successful spray coating of silicon microneedle arrays.

    Science.gov (United States)

    McGrath, Marie G; Vrdoljak, Anto; O'Mahony, Conor; Oliveira, Jorge C; Moore, Anne C; Crean, Abina M

    2011-08-30

    Coated microneedle patches have demonstrated potential for effective, minimally invasive, drug and vaccine delivery. To facilitate cost-effective, industrial-scale production of coated microneedle patches, a continuous coating method which utilises conventional pharmaceutical processes is an attractive prospect. Here, the potential of spray-coating silicon microneedle patches using a conventional film-coating process was evaluated and the key process parameters which impact on coating coalescence and weight were identified by employing a fractional factorial design to coat flat silicon patches. Processing parameters analysed included concentration of coating material, liquid input rate, duration of spraying, atomisation air pressure, gun-to-surface distance and air cap setting. Two film-coating materials were investigated; hydroxypropylmethylcellulose (HPMC) and carboxymethylcellulose (CMC). HPMC readily formed a film-coat on silicon when suitable spray coating parameter settings were determined. CMC films required the inclusion of a surfactant (1%, w/w Tween 80) to facilitate coalescence of the sprayed droplets on the silicon surface. Spray coating parameters identified by experimental design, successfully coated 280μm silicon microneedle arrays, producing an intact film-coat, which follows the contours of the microneedle array without occlusion of the microneedle shape. This study demonstrates a novel method of coating microneedle arrays with biocompatible polymers using a conventional film-coating process. It is the first study to indicate the thickness and roughness of coatings applied to microneedle arrays. The study also highlights the importance of identifying suitable processing parameters when film coating substrates of micron dimensions. The ability of a fractional factorial design to identify these critical parameters is also demonstrated. The polymer coatings applied in this study can potentially be drug loaded for intradermal drug and vaccine delivery

  2. Small-Scale Spray Releases: Orifice Plugging Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Blanchard, Jeremy; Kimura, Marcia L.; Kurath, Dean E.

    2012-09-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities, is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations published in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials present in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty introduced by extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches in which the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are largely absent. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine the aerosol release fractions and aerosol generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents (AFA) was assessed with most of the simulants. Orifices

  3. DROPLETS AND PARTICLES IN SPRAYS: TAILORING PARTICLE PROPERTIES WITHIN SPRAY PROCESSES

    Institute of Scientific and Technical Information of China (English)

    Udo Fritsching

    2005-01-01

    Particle generation via atomization and spray processes is a widely applied method for powder production.By means of atomization processes, the relevant particle properties may be tailored to the powder user's need in a wide range. Understanding and control of the main subprocesses of atomization is a key feature for choosing a suitable type of spray process and operation conditions. Tailoring particle properties and extending the applications of particle production beyond the current limits is also possible in this way. This contribution highlights some features of spray processes for powder production, namely the gas- and fluid-dynamic processes involved, the materials-related subprocesses, and the formation of the multiphase flow in the spray. As an example, the production of fibre- or sphere-shaped particles from melt atomization is discussed.

  4. Numerical Modeling of Spray Combustion with an Unstructured-Grid Method

    Science.gov (United States)

    Shang, H. M.; Chen, Y. S.; Liaw, P.; Shih, M. H.; Wang, T. S.

    1996-01-01

    The present unstructured-grid method follows strictly the basic finite volume forms of the conservation laws of the governing equations for the entire flow domain. High-order spatially accurate formulation has been employed for the numerical solutions of the Navier-Stokes equations. A two-equation k-epsilon turbulence model is also incorporated in the unstructured-grid solver. The convergence of the resulted linear algebraic equation is accelerated with preconditioned Conjugate Gradient method. A statistical spray combustion model has been incorporated into the present unstructured-grid solver. In this model, spray is represented by discrete particles, rather than by continuous distributions. A finite number of computational particles are used to predict a sample of total population of particles. Particle trajectories are integrated using their momentum and motion equations and particles exchange mass, momentum and energy with the gas within the computational cell in which they are located. The interaction calculations are performed simultaneously and eliminate global iteration for the two-phase momentum exchange. A transient spray flame in a high pressure combustion chamber is predicted and then the solution of liquid-fuel combusting flow with a rotating cup atomizer is presented and compared with the experimental data. The major conclusion of this investigation is that the unstructured-grid method can be employed to study very complicated flow fields of turbulent spray combustion. Grid adaptation can be easily achieved in any flow domain such as droplet evaporation and combustion zone. Future applications of the present model can be found in the full three-dimensional study of flow fields of gas turbine and liquid propulsion engine combustion chambers with multi-injectors.

  5. Spatially-resolved, three-dimensional spray characterization of impinging jets by digital in-line holography

    Science.gov (United States)

    Gao, Jian; Rodrigues, Neil; Sojka, Paul; Chen, Jun

    2014-11-01

    The impinging jet injector is a preferred method for the atomization of liquid rocket propellants. The majority of experimental studies in literature are not spatially-resolved due to the limitations of widely available point-wise and two-dimensional (2D) diagnostic techniques such as phase Doppler anemometry (PDA), which requires significant experimental repetitions to give spatially-resolved measurements. In the present study, digital in-line holography (DIH) is used to provide spatially-resolved, three-dimensional (3D) characteristics of impinging jet sprays. A double-exposure DIH setup is configured to measure droplet 3D, three-component velocity as well as the size distribution. The particle information is extracted by the hybrid method, which is recently proposed as a particle detection method. To enlarge the detection volume, two parallel, collimated laser beams are used to simultaneously probe the spray at two locations, and two identical cameras are used to record the corresponding holograms. Such a setup has a detection volume of approximately 20 cm by 3.6 cm by 4.8 cm. Sprays of both Newtonian and non-Newtonian liquids corresponding to regimes at relatively lower jet Reynolds and Weber numbers are investigated. Measurements from DIH are further verified by comparison with experimental data obtained from shadowgraph and PDA. It is revealed that DIH is particularly suitable to provide spatially-resolved, 3D measurements of impinging jet sprays that are not particularly dense.

  6. Influence of spraying distance and postcooling on cryogen spray cooling for dermatologic laser surgery

    Science.gov (United States)

    Aguilar, Guillermo; Majaron, Boris; Viator, John A.; Basinger, Brooke; Karapetian, Emil; Svaasand, Lars O.; Lavernia, Enrique J.; Nelson, J. Stuart

    2001-05-01

    Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage in various laser dermatological procedures such as treatment of port wine stain birthmarks and hair removal. However, the spray characteristics and combination of CSC and heating (laser) to obtain optimal treatments have not yet been determined. The distance between the nozzle tip and the skin surface for commercial devices was apparently chosen based on the position at which the cryogen spray reached a minimum temperature, presumably with the expectation that such a minimum would correspond to maximal heat flux. We have systematically measured spray characteristics of various nozzles, such as mean droplet diameter, velocity, temperature, and heat transfer coefficient, as a function of distance from the nozzle tip. Among other interesting correlations between these spray characteristics, it is shown that, for nozzle-to-skin distances between 20 to 80 mm, variations in the heat transfer coefficient are larger than those in the spray temperature and, therefore, maximization of the heat flux should be better dictated by the distance at which the heat transfer coefficient is maximized rather than that at which the spray temperature is minimized. Also, the influence of droplet diameter appears to be more influential on the heat transfer coefficient value than that of droplet velocity. Based on spray characteristic correlations, different ranges for positioning the nozzles are recommended, depending on the clinical application. Also, a 2D finite-difference method has been developed to study the spatial and temporal thermal variations within the skin. Our results show that it is possible to decrease significantly the epidermal damage after laser irradiation provided the heat transfer coefficient is significantly increased. The influence of post-cooling has minimal effects for the cases studied.

  7. Implementation and Development of an Eulerian Spray Model for CFD simulations of diesel Sprays

    OpenAIRE

    2016-01-01

    [EN] The main objective of this work is the modeling of diesel sprays under engine conditions, including the atomization, transport and evaporation processes pivotal in the diesel spray formation and its development. For this purpose, an Eulerian single fluid model, embedded in a RANS environment, is implemented in the CFD platform OpenFOAM. The modeling approach implemented here is based on the ⅀-Y model. The model is founded on the assumption of flow scales separation. In actual i...

  8. Laser treatment of plasma sprayed HA coatings

    NARCIS (Netherlands)

    Khor, KA; Vreeling, A; Dong, ZL; Cheang, P

    1999-01-01

    Laser treatment was conducted on plasma sprayed hydroxyapatite (HA) coatings using a Nd-YAG pulse laser. Various laser parameters were investigated. The results showed that the HA surface melted when an energy level of greater than or equal to 2 J and a spot size of 2 mm was employed during continuo

  9. Commissioning of laser assisted cold spraying technology

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2012-10-01

    Full Text Available This study demonstrates the potential of a newly designed, assembled and commissioned laser assisted cold spraying (LACS) technology at the National Laser Centre, Pretoria, South Africa, to deposit Al-12wt%Si coatings on stainless steel substrate...

  10. New atomization nozzle for spray drying

    NARCIS (Netherlands)

    Deventer, H.C. van; Houben, R.J.; Koldeweij, R.B.J.

    2013-01-01

    A new atomization nozzle based on ink jet technology is introduced for spray drying. Application areas are the food and dairy industry, in the first instance, because in these industries the quality demands on the final powders are high with respect to heat load, powder shape, and size distribution.

  11. Producing Quantum Dots by Spray Pyrolysis

    Science.gov (United States)

    Banger, Kulbinder; Jin, Michael H.; Hepp, Aloysius

    2006-01-01

    An improved process for making nanocrystallites, commonly denoted quantum dots (QDs), is based on spray pyrolysis. Unlike the process used heretofore, the improved process is amenable to mass production of either passivated or non-passivated QDs, with computer control to ensure near uniformity of size.

  12. New atomization nozzle for spray drying

    NARCIS (Netherlands)

    Deventer, H.C. van; Houben, R.J.; Koldeweij, R.B.J.

    2013-01-01

    A new atomization nozzle based on ink jet technology is introduced for spray drying. Application areas are the food and dairy industry, in the first instance, because in these industries the quality demands on the final powders are high with respect to heat load, powder shape, and size distribution.

  13. Spray Forming Aluminum - Final Report (Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    D. D. Leon

    1999-07-08

    The U.S. Department of Energy - Office of Industrial Technology (DOE) has an objective to increase energy efficient and enhance competitiveness of American metals industries. To support this objective, ALCOA Inc. entered into a cooperative program to develop spray forming technology for aluminum. This Phase II of the DOE Spray Forming Program would translate bench scale spray forming technology into a cost effective world class process for commercialization. Developments under DOE Cooperative Agreement No. DE-FC07-94ID13238 occurred during two time periods due to budgetary constraints; April 1994 through September 1996 and October 1997 and December 1998. During these periods, ALCOA Inc developed a linear spray forming nozzle and specific support processes capable of scale-up for commercial production of aluminum sheet alloy products. Emphasis was given to alloys 3003 and 6111, both being commercially significant alloys used in the automotive industry. The report reviews research performed in the following areas: Nozzel Development, Fabrication, Deposition, Metal Characterization, Computer Simulation and Economics. With the formation of a Holding Company, all intellectual property developed in Phases I and II of the Project have been documented under separate cover for licensing to domestic producers.

  14. Growth and cation accumulation in spray carnations

    NARCIS (Netherlands)

    Spithorst, L.S.

    1980-01-01

    Spray carnations (Dianthus caryophyllus ‘Exquisite’), planted as potted cuttings in December, had a maximum dry-matter production in summer of 22 g m−2 day−1, calculated for the net surface area completely covered by the crop. This value is fairly similar to the maxima established for outdoor crops

  15. Laser treatment of plasma sprayed HA coatings

    NARCIS (Netherlands)

    Khor, KA; Vreeling, A; Dong, ZL; Cheang, P

    1999-01-01

    Laser treatment was conducted on plasma sprayed hydroxyapatite (HA) coatings using a Nd-YAG pulse laser. Various laser parameters were investigated. The results showed that the HA surface melted when an energy level of greater than or equal to 2 J and a spot size of 2 mm was employed during continuo

  16. The erosive potential of candy sprays

    NARCIS (Netherlands)

    Gambon, D.L.; Brand, H.S.; Nieuw Amerongen, A.V.

    2009-01-01

    Objective To determine the erosive potential of seven different commercially available candy sprays in vitro and in vivo. Material and methods The erosive potential was determined in vitro by measuring the pH and neutralisable acidity. The salivary pH and flow rate were measured in healthy volunteer

  17. Research of Plasma Spraying Process on Aluminum-Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Patricija Kavaliauskaitė

    2016-04-01

    Full Text Available The article examines plasma sprayed 95Ni-5Al coatings on alu-minum-magnesium (Mg ≈ 2,6‒3,6 % alloy substrate. Alumi-num-magnesium samples prior spraying were prepared with mechanical treatment (blasting with Al2O3. 95Ni-5Al coatings on aluminum-magnesium alloys were sprayed with different parameters of process and coating‘s thickness, porosity, micro-hardness and microstructure were evaluated. Also numerical simulations in electric and magnetic phenomena of plasma spray-ing were carried out.

  18. Research on automatic spraying of single-walled carbon nanotubes and detection of spraying effects

    Directory of Open Access Journals (Sweden)

    Jianwen Zhao

    2014-04-01

    Full Text Available Single-walled carbon nanotubes (SWNTs have been introduced as compliant electrodes for dielectric elastomers (DEs due to fault tolerance. To acquire a better electrostrictive strain and longer lifetime, it is essential to obtain a certain and uniform width of the SWNT electrode. To ensure uniform width manually, a small flux and longer time are necessary. Moreover, it is difficult to control the width of the electrode for the randomness of manual spraying. Therefore, a new type of automatic spraying process is presented in this paper. The width and homogeneity of the electrode can be easily controlled by certain parameters of the process. Two methods for detecting the homogeneity of the electrode are introduced in this paper: Measurement of surface resistance and luminosity. The coefficient of variation (CV values detected by the two methods are virtually equal and less than 8%, which shows the feasibility of the detection method and homogeneity of automatic spraying. The speed of automatic spraying is 102 mm2/s, which is higher than that of manual spraying. The spraying process and the method used to detect homogeneity in this paper provide a reference for the relevant processes.

  19. Efficient control system for low-concentration inorganic gases from a process vent stream: application of surfactants in spray and packed columns.

    Science.gov (United States)

    Chein, Hungmin; Aggarwal, Shankar G; Wu, Hsin-Hsien

    2004-11-01

    Control of low-concentration pollutants from a semiconductor process vent stream using a wet-scrubbing technique is a challenging task to meet Taiwan environmental emission standards. An efficient wet-scrubber is designed on a pilot scale and tested to control low concentration acid and base waste-gas emission. The scrubber system consisted of two columns, i.e., a fine spray column [cutoff diameter (based on volume), Dv(50) = 15.63 microm; Sauter mean diameter (SMD) = 7.62 microm], which is especially efficient for NH3 removal as the pH of the spraying liquid is approximately 7 followed by a packed column with a scrubbing liquid pH approximately 9.0 mainly for acids removal. It is observed that use of the surfactants in low concentration about 10(-4) M and 10(-7) M in the spray liquid and in the scrubbing liquid, respectively, remarkably enhances the removal efficiency of the system. A traditional packed column (without the spray column and the surfactant) showed that the removal efficiencies of NH3, HF, and HCl for the inlet concentration range 0.2 to 3 ppm were (n = 5) 22.6+/-3.4%, 43.4+/-5.5%, and 40.4+/-7.4%, respectively. The overall efficiencies of the proposed system (the spray column and the packed column) in the presence of the surfactant in the spray liquid and in the scrubbing liquid forthese three species were found to increase significantly (n = 5) from 60.3+/-3.6 to 82.8+/-6.8%, 59.1+/-2.7 to 83.4+/-4.2%, and 56.2+/-7.3 to 81.0+/-6.7%, respectively. In this work, development of charge on the gas-liquid interface due to the surfactants has been measured and discussed. It is concluded that the presence of charge on the gas-liquid interface is the responsible factor for enhancement of the removal efficiency (mass-transfer in liquid phase). The effects of the type of surfactants, their chain length, concentration in liquid, etc. on the removal efficiency are discussed. Since the pilot tests were performed under the operating conditions similar to most of

  20. Short communication: The effect of liquid storage on the flavor of whey protein concentrate.

    Science.gov (United States)

    Park, Curtis W; Parker, Megan; Drake, MaryAnne

    2016-06-01

    Unit operations in dried dairy ingredient manufacture significantly influence sensory properties and, consequently, their use and consumer acceptance in a variety of ingredient applications. In whey protein concentrate (WPC) manufacture, liquid can be stored as whey or WPC before spray drying. The objective of this study was to determine the effect of storage, composition, and bleaching on the flavor of spray-dried WPC80. Liquid whey was manufactured and subjected to the following treatments: bleached or unbleached and liquid whey or liquid WPC storage. The experiment was replicated 3 times and included a no-storage control. All liquid storage was performed at 4°C for 24h. Flavor of the final spray-dried WPC80 was evaluated by a trained panel and volatile compound analyses. Storage of liquids increased cardboard flavor, decreased sweet aromatic flavor, and resulted in increased volatile lipid oxidation products. Bleaching altered the effect of liquid storage. Storage of unbleached liquid whey decreased sweet aromatic flavor and increased cardboard flavor and volatile lipid oxidation products compared with liquid WPC80 and no storage. In contrast, storage of bleached liquid WPC decreased sweet aromatic flavor and increased cardboard flavor and associated volatile lipid oxidation products compared with bleached liquid whey or no storage. These results confirm that liquid storage increases off-flavors in spray-dried protein but to a variable degree, depending on whether bleaching has been applied. If liquid storage is necessary, bleached WPC80 should be stored as liquid whey and unbleached WPC80 should be stored as liquid WPC to mitigate off-flavors.

  1. Liquid repellency by a moving plate

    Science.gov (United States)

    Bouillant, Ambre; Anais Gauthier Team; David Quere Team; Christophe Clanet Team

    2016-11-01

    Moving solids can repel impacting drops, owing to their motion. Provided the solid velocity is larger than a threshold value, air entrained at the vicinity of the moving plate prevents the drop from wetting, and makes it bounce. In addition, the rebound is oblique, which enhances the evacuation of liquid. We discuss experiments and models on this theme, and extend them to case of small droplets (such as formed in a spray) found to be even more efficiently repelled by the moving plate.

  2. Physical and immunogenic stability of spray freeze-dried influenza vaccine powder for pulmonary delivery : Comparison of inulin, dextran, or a mixture of dextran and trehalose as protectants

    NARCIS (Netherlands)

    Murugappan, Senthil; Patil, Harshad P; Kanojia, Gaurav; ter Veer, Wouter; Meijerhof, Tjarko; Frijlink, Henderik W; Huckriede, Anke; Hinrichs, Wouter L J

    2013-01-01

    One of the advantages of dry influenza vaccines over conventional liquid influenza vaccines is that they can be used for alternative routes of administration. Previous studies showed that spray freeze-drying is an excellent technique to prepare vaccine containing powders for pulmonary delivery U.P.

  3. Spray-On Foam Insulations for Launch Vehicle Cryogenic Tanks

    Science.gov (United States)

    Fesmire, J. E.; Cofman, B. E.; Menghelli, B. J.; Heckle, K. W.

    2011-01-01

    Spray-on foam insulation (SOFI) has been developed for use on the cryogenic tanks of space launch vehicles beginning in the 1960s with the Apollo program. The use of SOFI was further developed for the Space Shuttle program. The External Tank (ET) of the Space Shuttle, consisting of a forward liquid oxygen tank in line with an aft liquid hydrogen tank, requires thermal insulation over its outer surface to prevent ice formation and avoid in-flight damage to the ceramic tile thermal protection system on the adjacent Orbiter. The insulation also provides system control and stability with throughout the lengthy process of cooldown, loading, and replenishing the tank. There are two main types of SOFI used on the ET: acreage (with the rind) and closeout (machined surface). The thermal performance of the seemingly simple SOFI system is a complex of many variables starting with the large temperature difference of from 200 to 260 K through the typical 25-mm thickness. Environmental factors include air temperature and humidity, wind speed, solar exposure, and aging or weathering history. Additional factors include manufacturing details, launch processing operations, and number of cryogenic thermal cycles. The study of the cryogenic thermal performance of SOFI under large temperature differentials is the subject of this article. The amount of moisture taken into the foam during the cold soak phase, termed Cryogenic Moisture Uptake, must also be considered. The heat leakage rates through these foams were measured under representative conditions using laboratory standard liquid nitrogen boiloff apparatus. Test articles included baseline, aged, and weathered specimens. Testing was performed over the entire pressure range from high vacuum to ambient pressure. Values for apparent thermal conductivity and heat flux were calculated and compared with prior data. As the prior data of record was obtained for small temperature differentials on non-weathered foams, analysis of the

  4. Numerical and experimental analysis of vertical spray control patternators

    Directory of Open Access Journals (Sweden)

    F. Sarghini

    2013-09-01

    Full Text Available The experimental vertical spray control walls have the purpose of picking up the liquid delivered by trained sprayer for providing the liquid distribution profile in height. Theoretically this should correspond to the ideal profile, which consists in a uniform distribution on the vegetation. If the profile is different from the ideal, a parameter setup is required on the sprayer. Nonetheless, some problems are hidden in the aforementioned statements: i no wall measures exactly the distribution profile (i.e. the flow through the sections in the vertical plane, parallel to the direction of advancement of the sprayer. Compared to real profile, sensitive errors are introduced: the evaporation of the drops, the deviation of the air flows caused by the sensors panel themselves; by the possibility that the drops bounce on the wall panels, also due to the current of air that can push the liquid veil laterally or upwards, Moreover, everything varies depending on the geometry of the sensors, air velocity, air humidity; ii no one knows what exactly is the optimal distribution profile. It is often considered as optimal a profile that reflects the amount of leaf area subtended by each section absorber: however, it is evident that the path of the droplets changes according to the sprayer typology (eg. radial-flow or horizontal flows. In this work a combined numerical-experimental approach is adopted, in order to assess some of the aforementioned issues: numerical data obtained by using computational fluid dynamics models are compared and validated with experimental data, in order to assess the reliability of numerical simulations in configurations which are difficult to analyze using an experimental setup.

  5. A simplified model of aerosol removal by containment sprays

    Energy Technology Data Exchange (ETDEWEB)

    Powers, D.A. (Sandia National Labs., Albuquerque, NM (United States)); Burson, S.B. (Nuclear Regulatory Commission, Washington, DC (United States). Div. of Safety Issue Resolution)

    1993-06-01

    Spray systems in nuclear reactor containments are described. The scrubbing of aerosols from containment atmospheres by spray droplets is discussed. Uncertainties are identified in the prediction of spray performance when the sprays are used as a means for decontaminating containment atmospheres. A mechanistic model based on current knowledge of the physical phenomena involved in spray performance is developed. With this model, a quantitative uncertainty analysis of spray performance is conducted using a Monte Carlo method to sample 20 uncertain quantities related to phenomena of spray droplet behavior as well as the initial and boundary conditions expected to be associated with severe reactor accidents. Results of the uncertainty analysis are used to construct simplified expressions for spray decontamination coefficients. Two variables that affect aerosol capture by water droplets are not treated as uncertain; they are (1) [open quote]Q[close quote], spray water flux into the containment, and (2) [open quote]H[close quote], the total fall distance of spray droplets. The choice of values of these variables is left to the user since they are plant and accident specific. Also, they can usually be ascertained with some degree of certainty. The spray decontamination coefficients are found to be sufficiently dependent on the extent of decontamination that the fraction of the initial aerosol remaining in the atmosphere, m[sub f], is explicitly treated in the simplified expressions. The simplified expressions for the spray decontamination coefficient are given. Parametric values for these expressions are found for median, 10 percentile, and 90 percentile values in the uncertainty distribution for the spray decontamination coefficient. Examples are given to illustrate the utility of the simplified expressions to predict spray decontamination of an aerosol-laden atmosphere.

  6. An experimental methodology to quantify the spray cooling event at intermittent spray impact

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Antonio L.N. [Instituto Superior Tecnico, Mechanical Engineering Department, Center for Innovation, Technology and Policy Research, IN Av. Rovisco Pais 1049-001, Lisbon Codex (Portugal)]. E-mail: moreira@dem.ist.utl.pt; Carvalho, Joao [Instituto Superior Tecnico, Mechanical Engineering Department, Center for Innovation, Technology and Policy Research, IN Av. Rovisco Pais 1049-001, Lisbon Codex (Portugal); Panao, Miguel R.O. [Instituto Superior Tecnico, Mechanical Engineering Department, Center for Innovation, Technology and Policy Research, IN Av. Rovisco Pais 1049-001, Lisbon Codex (Portugal)

    2007-04-15

    The present paper describes an experimental methodology devised to study spray cooling with multiple-intermittent sprays as those found in fuel injection systems of spark-ignition and diesel engines, or in dermatologic surgery applications. The spray characteristics and the surface thermal behaviour are measured by combining a two-component phase-Doppler anemometer with fast response surface thermocouples. The hardware allows simultaneous acquisition of Doppler and thermocouple signals which are processed in Matlab to estimate the time-varying heat flux and fluid-dynamic characteristics of the spray during impact. The time resolution of the acquisition system is limited by the data rate of validation of the phase-Doppler anemometer, but it has been shown to be accurate for the characterization of spray-cooling processes with short spurt durations for which the transient period of spray injection plays an important role. The measurements are processed in terms of the instantaneous heat fluxes, from which phase-average values of the boiling curves are obtained. Two of the characteristic parameters used in the thermal analysis of stationary spray cooling events, the critical heat flux (CHF) and Leidenfrost phenomenon, are then inferred in terms of operating conditions of the multiple-intermittent injections, such as the frequency, duration and pressure of injection. An integral method is suggested to describe the overall process of heat transfer, which accounts for the fluid-dynamic heterogeneities induced by multiple and successive droplet interactions within the area of spray impact. The method considers overall boiling curves dependant on the injection conditions and provides an empirical tool to characterize the heat transfer processes on the impact of multiple-intermittent sprays. The methodology is tested in a preliminary study of the effect of injection conditions on the heat removed by a fuel spray striking the back surface of the intake valve as in spark

  7. A parametric study of the confined spraying distance, solution concentration, and spraying time for the spraying technique used to fabricate PS superhydrophobic surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Myoung; Cho, Young Sam [Wonkwang University, Iksan (Korea, Republic of)

    2015-11-15

    In this study, a parametric study was performed for the spraying technique used to fabricate polystyrene (PS) superhydrophobic surfaces. The spraying distance, the spraying time and the polymer concentration were selected as the parameters to be varied. Tetrahydrofuran (THF) was used for the solvent. First, a dissolved PS solution in THF was prepared. Then, the dissolved PS solution was sprayed onto the coverglass. The Nozzle size, working pressure, glove box temperature and humidity were fixed at 0.2 mm, 0.2 MPa, 23.15±0.83 .deg. C and 54.13±1.46%, respectively. After that, the surface morphology of the sprayed surface and water contact angle (WCA) were assessed by Scanning electron microscopy (SEM) and a contact angle meter. According to the spraying distance increased, the WCA was decreased in all three cases of the 1.5 vol% PS solution. However, the WCA was approximately 158 .deg. regardless of the spraying time or distance in all three cases of 6.0 vol% PS solution. The amount of PS deposited per unit area was shown to be the key parameter in determining the hydrophobicity, as expected. However, the PS concentration and the spraying distance affected the hydrophobicity regardless of the amount of PS deposited. Additionally, using least-squares method of the Origin 8.1 program fitting procedures for the WCA results, a water-contact-angle map of the PS-sprayed specimen was generated within the experimental parameters.

  8. Investigations on multicycle spray detonations

    Institute of Scientific and Technical Information of China (English)

    LI Mu; YAN Chuanjun; ZHENG Longxi; WANG Zhiwu; QIU Hua

    2007-01-01

    Experimental investigations were carried out on a 50-I.D. Multicycle pulse detonation engine (PDE) model, and liquid fuel (gasoline) was used. The average of pressure peak, as measured by piezoelectricity pressure transducer, increased versus distance to thrust wall before fully-developed detonation came into being. According to the pressure history, the pressure in detonation tube would not rise abruptly until the flame front advanced a certain distance downstream the spark. Just at that moment, two compression waves spreading to opposite direction were formed. One was enforced by combustion and became detonation rapidly. The other was weakened because of obstacles and insufficiency of fuel. Two methods were used to determine the induction length of two-phase detonation wave through the pressure history. Ignition delay time was found to be longer than deflagration-to-detonation transition (DDT) time, and the sum of the two would change little as cycle frequency increased. So they could be the most important factors controlling two-phase PDE frequency. Filling process and blowdown process were also analyzed.

  9. Dry Powder Precursors of Cubic Liquid Crystalline Nanoparticles (cubosomes)

    Science.gov (United States)

    Spicer, Patrick T.; Small, William B.; Small, William B.; Lynch, Matthew L.; Burns, Janet L.

    2002-08-01

    Cubosomes are dispersed nanostructured particles of cubic phase liquid crystal that have stimulated significant research interest because of their potential for application in controlled-release and drug delivery. Despite the interest, cubosomes can be difficult to fabricate and stabilize with current methods. Most of the current work is limited to liquid phase processes involving high shear dispersion of bulk cubic liquid crystalline material into sub-micron particles, limiting application flexibility. In this work, two types of dry powder cubosome precursors are produced by spray-drying: (1) starch-encapsulated monoolein is produced by spray-drying a dispersion of cubic liquid crystalline particles in an aqueous starch solution and (2) dextran-encapsulated monoolein is produced by spray-drying an emulsion formed by the ethanol-dextran-monoolein-water system. The encapsulants are used to decrease powder cohesion during drying and to act as a soluble colloidal stabilizer upon hydration of the powders. Both powders are shown to form (on average) 0.6 μm colloidally-stable cubosomes upon addition to water. However, the starch powders have a broader particle size distribution than the dextran powders because of the relative ease of spraying emulsions versus dispersions. The developed processes enable the production of nanostructured cubosomes by end-users rather than just specialized researchers and allow tailoring of the surface state of the cubosomes for broader application.

  10. Experimental Investigation of the Dispersion of Liquids by Ejection Atomizers

    Science.gov (United States)

    Arkhipov, V. A.; Bondarchuk, S. S.; Evsevleev, M. Ya.; Zharova, I. K.; Zhukov, A. S.; Zmanovskii, S. V.; Kozlov, E. A.; Konovalenko, A. I.; Trofimov, V. F.

    2013-11-01

    This paper presents the results of an experimental investigation of the dispersivity of liquid droplets in the spray cone of ejection atomizers. The calculational droplet size distribution function was measured by the method of low angles of the probe laser radiation scattering indicatrix on a pneumohydraulic bench under cold blow conditions. The efficiency of the proposed circuit designs of atomizers has been analyzed.

  11. Cryogenic spray vaporization in high-velocity helium, argon and nitrogen gasflows

    Science.gov (United States)

    Ingebo, Robert D.

    1993-01-01

    Effects of gas properties on cryogenic liquid-jet atomization in high-velocity helium, nitrogen, and argon gas flows were investigated. Volume median diameter, D(sub v.5e), data were obtained with a scattered-light scanning instrument. By calculating the change in spray drop size, -Delta D(sub v.5)(exp 2), due to droplet vaporization, it was possible to calculate D(sub v.5C). D(sub v.5C) is the unvaporized characteristic drop size formed at the fuel-nozzle orifice. This drop size was normalized with respect to liquid-jet diameter, D(sub O). It was then correlated with several dimensionless groups to give an expression for the volume median diameter of cryogenic LN2 sprays. This expression correlates drop size D(sub v.5c) with aerodynamic and liquid-surface forces so that it can be readily determined in the design of multiphase-flow propellant injectors for rocket combustors.

  12. Developments in Spray Modeling in Diesel and Direct-Injection Gasoline Engines Progrès de la modélisation des sprays dans les moteurs Diesel et à essence

    Directory of Open Access Journals (Sweden)

    Kong S. C.

    2006-12-01

    Full Text Available In direct-injection engines, the fuel spray characteristics influence the combustion efficiency and exhaust emissions. The performance of available spray models for predicting liquid and vapor fuel distributions, and their influence on combustion is reviewed for both diesel and gasoline direct injection engines. A phenomenological nozzle flow model is described for simulating the effects of diesel injector nozzle internal geometry on the fuel injection and spray processes. The flow model provides initial conditions for the liquid jet breakup model that considers wave instabilities due to Kelvin-Helmholtz (KH and Rayleigh-Taylor (RT mechanisms. A linearized instability analysis has also been extended to consider the breakup of liquid sheets for modeling pressure-swirl gasoline injectors. Diesel engine predictions have been compared with extensive data from in-cylinder laser diagnostics carried out in optically accessible heavy-duty, DI Diesel engines over a wide range of operating conditions. The results show that the nozzle flow model used in combination with the KH and RT models gives realistic spray predictions. In particular, the limited liquid fuel penetration length observed experimentally and the flame shape details are captured accurately. The liquid sheet breakup model has also been compared favorably with experimental spray penetration and drop size data for gasoline hollow-cone sprays. This model is currently being applied to study stratified charge combustion in GDI engines. Dans les moteurs à injection directe, les caractéristiques du spray de carburant influent directement sur le rendement et les émissions. Les performances des modèles de spray existants et leur influence sur la combustion pour les moteurs Diesel et essence à injection directe sont analysées. Un modèle phénoménologique d'écoulement dans les injecteurs indiquant les effets de la géométrie sur les processus d'injection est présenté. Ce modèle donne les

  13. Effect of Solution Spray Rate on the Properties of Chemically Sprayed ZnO:In Thin Films

    Directory of Open Access Journals (Sweden)

    Merike Kriisa

    2013-01-01

    Full Text Available ZnO:In thin films were grown from 100 mL of spray solution on glass substrates by chemical spray at Ts=400°C using solution spray rates of 0.5–6.7 mL/min. Zinc acetate and indium(IIIchloride were used as Zn and In sources, respectively, with [In]/[Zn] = 3 at.%. Independent of solution spray rate, the crystallites in ZnO:In films grow preferentially in the (101 plane parallel to the substrate. The solution spray rate influences the surface morphology, grain size, film thickness, and electrical and optical properties. According to SEM and AFM studies, sharp-edged pyramidal grains and canvas-resembling surfaces are characteristic of films grown at spray rates of 0.5 and 3.3 mL/min, respectively. To obtain films with comparable film thickness and grain size, more spray solution should be used at low spray rates. The electrical resistivity of sprayed ZnO:In films is controlled by the solution spray rate. The carrier concentration increases from 2·1019 cm−3 to 1·1020 cm−3 when spray rate is increased from 0.5 mL/min to 3.3 mL/min independent of the film thickness; the carrier mobilities are always lower in slowly grown films. Sprayed ZnO:In films transmit 75–80% of the visible light while the increase in solution spray rate from 0.5 mL/min to 3.3 mL/min decreases the transmittance in the NIR region and increases the band gap in accordance with the increase in carrier concentration. Lower carrier concentration in slowly sprayed films is likely due to the indium oxidation.

  14. To spray or not to spray? Understanding participation in an indoor residual spray campaign in Arequipa, Peru.

    Science.gov (United States)

    Paz-Soldán, Valerie A; Bauer, Karin M; Hunter, Gabrielle C; Castillo-Neyra, Ricardo; Arriola, Vanessa D; Rivera-Lanas, Daniel; Rodriguez, Geoffrey H; Toledo Vizcarra, Amparo M; Mollesaca Riveros, Lina M; Levy, Michael Z; Buttenheim, Alison M

    2016-05-17

    Current low participation rates in vector control programmes in Arequipa, Peru complicate the control of Chagas disease. Using focus groups (n = 17 participants) and semi-structured interviews (n = 71) conducted in March and May 2013, respectively, we examined barriers to and motivators of household participation in an indoor residual spray (IRS) campaign that had taken place one year prior in Arequipa. The most common reported barriers to participation were inconvenient spray times due to work obligations, not considering the campaign to be necessary, concerns about secondary health impacts (e.g. allergic reactions to insecticides), and difficulties preparing the home for spraying (e.g. moving heavy furniture). There was also a low perception of risk for contracting Chagas disease that might affect participation. The main motivator to participate was to ensure personal health and well-being. Future IRS campaigns should incorporate more flexible hours, including weekends; provide appropriate educational messages to counter concerns about secondary health effects; incorporate peer educators to increase perceived risk to Chagas in community; obtain support from community members and leaders to build community trust and support for the campaign; and assist individuals in preparing their homes. Enhancing community trust in both the need for the campaign and its operations is key.

  15. Applying Spray Drying to Customized Powder Manufacture%用喷雾干燥方法制造具有指定特性的颗粒

    Institute of Scientific and Technical Information of China (English)

    Keith Masters

    2004-01-01

    Spray drying is an important continuous industrial process for drying pumpable liquid formulations irrespective of their heat sensitivity, rheology, solids content and processing rate. Furthermore spray drying has the capability through drying chamber design, plant layout and mode of operation to produce dried products of specific particulate size and morphology. These are important aspects when spray drying technology is applied to the needs of customized powder manufacture. There are many examples in industry where spray dried powders have to meet stringent specifications set by such factors as end-product powder quality standards dictated by global competition,dry raw material characteristics required for optimum downstream processing, and dry materials handling to comply with environmental, health and safety issues. Spray drying is no longer regarded just as a convective industrial drying concept, but also as an integral part of modern manufacturing practices applying powder technology. This paper reviews the aspects of spray dryer design and operation for consideration when customized powder manufacture is involved.

  16. Refractoriless liquid fuel burner

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.E.

    1986-07-15

    A liquid fuel burner head is described which consists of: A. a generally annular burner head housing spacedly enveloping a generally cylindrical primary air assembly, the head and assembly each having corresponding forward and rearward ends, (a) the primary air assembly having a plurality of internal primary air supply passage means extending in a generally forwardly direction in the assembly and emerging through annularly disposed primary air port means at the forward end of the primary air assembly, (b) means effective to produce a swirl of primary air in one direction about the axis of the primary air assembly as the air emerges from the primary air port means, (c) means associated with the primary air port means for adjusting the location of flame origin forward of and relative to the primary air port means, (d) the primary air assembly including a liquid fuel supply passage and a nozzle, the nozzle being centrally disposed at the forward end of the primary air assembly and encompassed by the primary air port means, the liquid fuel nozzle being effective to discharge a substantially fan-like spray of liquid fuel just forward of and across the primary air port means, (e) the primary air assembly and the nozzle together being axially movable relative to the housing between forwardmost and rearwardmost positions respectively responsive to change in burner firing rate between minimum and maximum; B. secondary air supply passage means disposed in the space between the housing and the primary air assembly; C. means rearwardly of the secondary air directional means and port means effective to meter the amount of secondary air supplied air port means from a lesser quantity when the primary air assembly and nozzle are in their forwardmost position to a greater quantity when the primary air assembly and nozzle are in their rearwardmost position.

  17. Study of Multi-Function Micro-Plasma Spraying Technology

    Institute of Scientific and Technical Information of China (English)

    WANG Liuying; WANG Hangong; HUA Shaochun; CAO Xiaoping

    2007-01-01

    A multi-functional micro-arc plasma spraying system was developed according to aerodynamics and plasma spray theory. The soft switch IGBT (Insulated Gate Bipolar Transistor) invert technique, micro-computer control technique, convergent-divergent nozzle structure and axial powder feeding techniques have been adopted in the design of the micro-arc plasma spraying system. It is not only characterized by a small volume, a light weight, highly accurate control, high deposition efficiency and high reliability, but also has multi-functions in plasma spraying, welding and quenching. The experimental results showed that the system can produce a supersonic flame at a low power, spray Al2O3 particles at an average speed up to 430 m/s, and make nanostructured AT13 coatings with an average bonding strength of 42.7 MPa. Compared to conventional 9M plasma spraying with a higher power, the coatings with almost the same properties as those by conventional plasma spray can be deposited by multi-functional micro-arc plasma spraying with a lower power plasma arc due to an improved power supply design, spray gun structure and powder feeding method. Moreover, this system is suitable for working with thin parts and undertaking on site repairs, and as a result, the application of plasma spraying will be greatly extended.

  18. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction.

    Science.gov (United States)

    Fritz, Bradley K; Hoffmann, W Clint

    2016-09-16

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected.

  19. Identification and Modeling of Froth to Spray Transition on Sieve Trays

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The transition from froth to spray regime on sieve trays was experimentally studied in an air/water simulator with 300mm diameter. It has been found that the regime transition occurs as the clear liquid height is equal to the residual pressure drop on the trays. A convenient and accurate technique was proposed for determination of the regime transition point. Based on analysis of the transition process at a sieve hole, a new formula which can be used to correlate the experimental results was provided.

  20. Standard addition strip for quantitative electrostatic spray ionization mass spectrometry analysis: determination of caffeine in drinks.

    Science.gov (United States)

    Tobolkina, Elena; Qiao, Liang; Roussel, Christophe; Girault, Hubert H

    2014-12-01

    Standard addition strips were prepared for the quantitative determination of caffeine in different beverages by electrostatic spray ionization mass spectrometry (ESTASI-MS). The gist of this approach is to dry spots of caffeine solutions with different concentrations on a polymer strip, then to deposit a drop of sample mixed with an internal standard, here theobromine on each spot and to measure the mass spectrometry signals of caffeine and theobromine by ESTASI-MS. This strip approach is very convenient and provides quantitative analyses as accurate as the classical standard addition method by MS or liquid chromatography.

  1. Effect of thermal spray processes on microstructures and properties of Ni-20%Cr coatings

    Directory of Open Access Journals (Sweden)

    Pittaya Kuntasudjai

    2006-05-01

    Full Text Available Ni-20%Cr coatings were produced using different thermal spray techniques, which were spray and fuse, flame spray and arc spray. The Ni-20%Cr powder was sprayed onto a mild steel substrate using the spray and fuse and the flame spray systems, while the Ni-20%Cr wire was sprayed using the arc spray system. SEM microstructures of the coatings suggested the spraying conditions used were able to produce dense microstructures. However, the microstructure of the arc sprayed coatings showed fine lamellar characteristics compared to the coatings prepared by the spray and fuse and the flame spray techniques. Chemical elements and oxide were quantified by EDS-SEM technique. Differences in microstructure and coating characteristics such as content of porosity and oxide due to different processing techniques significantly affected the coating properties such as adhesion strength, hardness and wear rate.

  2. Thermal Spray Formation of Polymer Coatings

    Science.gov (United States)

    Coquill, Scott; Galbraith, Stephen L.; Tuss. Darren L.; Ivosevic, Milan

    2008-01-01

    This innovation forms a sprayable polymer film using powdered precursor materials and an in-process heating method. This device directly applies a powdered polymer onto a substrate to form an adherent, mechanically-sound, and thickness-regulated film. The process can be used to lay down both fully dense and porous, e.g., foam, coatings. This system is field-deployable and includes power distribution, heater controls, polymer constituent material bins, flow controls, material transportation functions, and a thermal spray apparatus. The only thing required for operation in the field is a power source. Because this method does not require solvents, it does not release the toxic, volatile organic compounds of previous methods. Also, the sprayed polymer material is not degraded because this method does not use hot combustion gas or hot plasma gas. This keeps the polymer from becoming rough, porous, or poorly bonded.

  3. Development of process data capturing, analysis and controlling for thermal spray techniques - SprayTracker

    Science.gov (United States)

    Kelber, C.; Marke, S.; Trommler, U.; Rupprecht, C.; Weis, S.

    2017-03-01

    Thermal spraying processes are becoming increasingly important in high-technology areas, such as automotive engineering and medical technology. The method offers the advantage of a local layer application with different materials and high deposition rates. Challenges in the application of thermal spraying result from the complex interaction of different influencing variables, which can be attributed to the properties of different materials, operating equipment supply, electrical parameters, flow mechanics, plasma physics and automation. In addition, spraying systems are subject to constant wear. Due to the process specification and the high demands on the produced coatings, innovative quality assurance tools are necessary. A central aspect, which has not yet been considered, is the data management in relation to the present measured variables, in particular the spraying system, the handling system, working safety devices and additional measuring sensors. Both the recording of all process-characterizing variables, their linking and evaluation as well as the use of the data for the active process control presuppose a novel, innovative control system (hardware and software) that was to be developed within the scope of the research project. In addition, new measurement methods and sensors are to be developed and qualified in order to improve the process reliability of thermal spraying.

  4. Gas entrainment by one single French PWR spray, SARNET-2 spray benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Malet, J., E-mail: jeanne.malet@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire, Saclay (France); Mimouni, S., E-mail: stephane.mimouni@edf.fr [Electricité de France, EDF MF2E, Chatou (France); Manzini, G., E-mail: giovanni.manzini@rse-web.it [RSE, Milano (Italy); Xiao, J., E-mail: jianjun.xiao@kit.edu [IKET, KIT, Karlsruhe (Germany); Vyskocil, L., E-mail: vyl@ujv.cz [UJV Rez (Czech Republic); Siccama, N.B., E-mail: siccama@nrg.eu [NRG, Safety and Power (Netherlands); Huhtanen, R., E-mail: risto.huhtanen@vtt.fi [VTT, PO Box 1000, FI-02044 VTT (Finland)

    2015-02-15

    Highlights: • This paper presents a benchmark performed in the frame of the SARNET-2 EU project. • It concerns momentum transfer between a PWR spray and the surrounding gas. • The entrained gas velocities can vary up to 100% from one code to another. • Simplified boundary conditions for sprays are generally used by the code users. • It is shown how these simplified conditions impact the gas entrainment. - Abstract: This paper presents a benchmark performed in the frame of the SARNET-2 EU project, dealing with momentum transfer between a real-scale PWR spray and the surrounding gas. It presents a description of the IRSN tests on the CALIST facility, the participating codes (8 contributions), code-experiment and code-to-code comparisons. It is found that droplet velocities are almost well calculated one meter below the spray nozzle, even if the spread of the spray is not recovered and the values of the entrained gas velocity vary up to 100% from one code to another. Concerning sensitivity analysis, several ‘simplifications’ have been made by the contributors, especially based on the boundary conditions applied at the location where droplets are injected. It is shown here that such simplifications influence droplet and entrained gas characteristics. The next step will be to translate these conclusions in terms of variables representative of interesting parameters for nuclear safety.

  5. Small-Scale Spray Releases: Initial Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2013-05-29

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and net generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of antifoam agents was assessed with most of the simulants. Orifices included round holes and

  6. Small-Scale Spray Releases: Initial Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2012-11-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and

  7. Large-Scale Spray Releases: Initial Aerosol Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Schonewill, Philip P.; Gauglitz, Phillip A.; Bontha, Jagannadha R.; Daniel, Richard C.; Kurath, Dean E.; Adkins, Harold E.; Billing, Justin M.; Burns, Carolyn A.; Davis, James M.; Enderlin, Carl W.; Fischer, Christopher M.; Jenks, Jeromy WJ; Lukins, Craig D.; MacFarlan, Paul J.; Shutthanandan, Janani I.; Smith, Dennese M.

    2012-12-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. Two key technical areas were identified where testing results were needed to improve the technical basis by reducing the uncertainty due to extrapolating existing literature results. The first technical need was to quantify the role of slurry particles in small breaches where the slurry particles may plug and result in substantially reduced, or even negligible, respirable fraction formed by high-pressure sprays. The second technical need was to determine the aerosol droplet size distribution and volume from prototypic breaches and fluids, specifically including sprays from larger breaches with slurries where data from the literature are scarce. To address these technical areas, small- and large-scale test stands were constructed and operated with simulants to determine aerosol release fractions and generation rates from a range of breach sizes and geometries. The properties of the simulants represented the range of properties expected in the WTP process streams and included water, sodium salt solutions, slurries containing boehmite or gibbsite, and a hazardous chemical simulant. The effect of anti-foam agents was assessed with most of the simulants. Orifices included round holes and

  8. Plasma Spray Forming of Nanostructured Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The nanostructure composite coating is obtained via plasma spraying of Al2O3-13 wt pct TiO2 powder. Brittle and hard lamella results from melted nanostructured powder. Ductile nanostructured matrix forms from unmelted nanostructured particles. Through the adjustment of constituent and nanostructure, hardness/strength and toughness/ductility are balanced and overall properties of the structure composite are achieved.

  9. Advanced Diagnostics for High Pressure Spray Combustion.

    Energy Technology Data Exchange (ETDEWEB)

    Skeen, Scott A.; Manin, Julien Luc; Pickett, Lyle M.

    2014-06-01

    The development of accurate predictive engine simulations requires experimental data to both inform and validate the models, but very limited information is presently available about the chemical structure of high pressure spray flames under engine- relevant conditions. Probing such flames for chemical information using non- intrusive optical methods or intrusive sampling techniques, however, is challenging because of the physical and optical harshness of the environment. This work details two new diagnostics that have been developed and deployed to obtain quantitative species concentrations and soot volume fractions from a high-pressure combusting spray. A high-speed, high-pressure sampling system was developed to extract gaseous species (including soot precursor species) from within the flame for offline analysis by time-of-flight mass spectrometry. A high-speed multi-wavelength optical extinction diagnostic was also developed to quantify transient and quasi-steady soot processes. High-pressure sampling and offline characterization of gas-phase species formed following the pre-burn event was accomplished as well as characterization of gas-phase species present in the lift-off region of a high-pressure n-dodecane spray flame. For the initial samples discussed in this work several species were identified, including polycyclic aromatic hydrocarbons (PAH); however, quantitative mole fractions were not determined. Nevertheless, the diagnostic developed here does have this capability. Quantitative, time-resolved measurements of soot extinction were also accomplished and the novel use of multiple incident wavelengths proved valuable toward characterizing changes in soot optical properties within different regions of the spray flame.

  10. Spray flow-network flow transition of binary Lennard-Jones particle system

    KAUST Repository

    Inaoka, Hajime

    2010-07-01

    We simulate gas-liquid flows caused by rapid depressurization using a molecular dynamics model. The model consists of two types of Lennard-Jones particles, which we call liquid particles and gas particles. These two types of particles are distinguished by their mass and strength of interaction: a liquid particle has heavier mass and stronger interaction than a gas particle. By simulations with various initial number densities of these particles, we found that there is a transition from a spray flow to a network flow with an increase of the number density of the liquid particles. At the transition point, the size of the liquid droplets follows a power-law distribution, while it follows an exponential distribution when the number density of the liquid particles is lower than the critical value. The comparison between the transition of the model and that of models of percolation is discussed. The change of the average droplet size with the initial number density of the gas particles is also presented. © 2010 Elsevier B.V. All rights reserved.

  11. Release of airborne particles and Ag and Zn compounds from nanotechnology-enabled consumer sprays: Implications for inhalation exposure

    Science.gov (United States)

    Calderón, Leonardo; Han, Taewon T.; McGilvery, Catriona M.; Yang, Letao; Subramaniam, Prasad; Lee, Ki-Bum; Schwander, Stephan; Tetley, Teresa D.; Georgopoulos, Panos G.; Ryan, Mary; Porter, Alexandra E.; Smith, Rachel; Chung, Kian Fan; Lioy, Paul J.; Zhang, Junfeng; Mainelis, Gediminas

    2017-04-01

    The increasing prevalence and use of nanotechnology-enabled consumer products have increased potential consumer exposures to nanoparticles; however, there is still a lack of data characterizing such consumer exposure. The research reported here investigated near-field airborne exposures due to the use of 13 silver (Ag)-based and 5 zinc (Zn)-based consumer sprays. The products were sprayed into a specially designed glove box, and all products were applied with equal spraying duration and frequency. Size distribution and concentration of the released particles were assessed using a Scanning Mobility Particle Sizer and an Aerodynamic Particle Sizer. Inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate the presence of metals in all investigated products. Spray liquids and airborne particles from select products were examined using transmission electron microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDS). We found that all sprays produced airborne particles ranging in size from nano-sized particles (2.5 μm); however, there was a substantial variation in the released particle concentration depending on a product. The total aerosol mass concentration was dominated by the presence of coarse particles, and it ranged from ∼30 μg/m3 to ∼30,000 μg/m3. The TEM verified the presence of nanoparticles and their agglomerates in liquid and airborne states. The products were found to contain not only Ag and Zn compounds - as advertised on the product labeling - but also a variety of other metals including lithium, strontium, barium, lead, manganese and others. The results presented here can be used as input to model population exposures as well as form a basis for human health effects studies due to the use nanotechnology-enabled products.

  12. Smooth Sliding Mode Control for Trajectory Tracking of Greenhouse Spraying Mobile Robot

    Directory of Open Access Journals (Sweden)

    Fang Zhiming

    2013-02-01

    Full Text Available For the spraying mobile robot working in greenhouse, due to the inconsistency of drive motors and the rough walking surface, it is easy to track off. For the liquidity of pesticide, the load always changes even the speed jumps. Because of these uncertainties, external disturbances and the difficulty of constructing the system dynamic model, it is hard to implement the trajectory tracking control of the spraying mobile robot steadily, precisely and quickly. In order to solve the problem, a smooth sliding mode trajectory tracking control method is proposed based on the distribute control strategy for each branch. Moreover, its stability is proved using the Lyapunov function. The simulation results show that the proposed method can track the reference trajectories precisely, quickly and steadily under the strong white noise. The chattering phenomenon of the control law is restrained compared to the conventional sliding mode control. The trajectory tracking performance is better than that of the fuzzy control. The designed method is easy to realize and doesn’t need to construct the precise mathematical model, so, it affords an economical and convenient control method for solving the trajectory tracking problem of the greenhouse spraying mobile robot under various uncertain interferences.

  13. Spray and microjets produced by focusing a laser pulse into a hemispherical drop

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2009-11-02

    We use high-speed video imaging to study laser disruption of the free surface of a hemispheric drop. The drop sits on a glass surface and the Nd:YAG (yttrium aluminum garnet) laser pulse propagates through the drop and is focused near the free surface from below. We focus on the evolution of the cylindrical liquid sheet and spray which emerges out of the drop and resembles typical impact crowns. The tip of the sheet emerges at velocities over 1 km/s. The tip of the crown breaks up into fine spray some of which is sucked back into the growing cavity at about 100 m/s. We measure the size of the typical spray droplets to be about 3 μm. We also show the formation of fine microjets, which are produced when the laser is focused inside the drop and the shock front hits small bubbles sitting under the free surface. For water these microjets are 5–50 μm in diameter and exit at 100–250 m/s. For higher viscositydrops, these jets can emerge at over 500 m/s.

  14. Drying of α-amylase by spray drying and freeze-drying - a comparative study

    Directory of Open Access Journals (Sweden)

    S. S. de Jesus

    2014-09-01

    Full Text Available This study is aimed at comparing two traditional methods of drying of enzymes and at verifying the efficiency of each one and their advantages and disadvantages. The experiments were performed with a laboratory spray dryer and freeze-dryer using α-amylase as the model enzyme. An experimental design in star revealed that spray drying is mainly influenced by the inlet air temperature and feed flow rate, which were considered to be the main factors influencing the enzymatic activity and water activity; the long period of material exposure to high temperatures causes a partial activity loss. In the experiments of freeze drying, three methods of freezing were used (freezer, acetone and dry ice, and liquid nitrogen and samples subsequently freeze-dried for times ranging between 0-24 hours. The product obtained from the two techniques showed high enzymatic activity and low water activity. For the drying of heat-resistant enzymes, in which the product to be obtained does not have high added value, spray drying may be more economically viable because, in the freeze drying process, the process time can be considered as a limiting factor when choosing a technique.

  15. Numerical Investigation on Primary Atomization Mechanism of Hollow Cone Swirling Sprays

    Directory of Open Access Journals (Sweden)

    Jia-Wei Ding

    2016-01-01

    Full Text Available The atomization process of swirling sprays in gas turbine engines has been investigated using a LES-VOF model. With fine grid resolution, the ligament and droplet formation processes are captured in detail. The spray structure of fully developed sprays and the flow field are observed firstly. A central recirculation zone is generated inside the hollow cone section due to the entrainment of air by the liquid sheet and strong turbulent structures promote the breakup of ligaments. At the exit of injector nozzle, surface instability occurs due to disturbance factors. Axial and transverse mode instabilities produce a net-like structure ligament zone. Finally, the generation mechanism of the droplet is analyzed. It is found that the breakup mechanism of ligaments is located at the Raleigh capillary region. Axial symmetry oscillation occurs due to the surface tension force and the capillary waves pinch off from the neck of the ligaments. Secondary breakup and coalescence occur at the “droplet zone,” resulting in a wider distribution curve at the downstream area.

  16. Spray visualization by laser sheet tomography; Laser sheet ni yoru funmu danmen no kashikaho

    Energy Technology Data Exchange (ETDEWEB)

    Oda, T.; Hiroyasu, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1996-07-21

    Laser sheet tomography was applied to the visualization of the cross section of a spray. In this method, fluorescent dye, eosine-Y(C20H6Br4Na2O), was used at a concentration of 10 g/l of the injectant, water, and the light source which illuminated the spray was a Nd: YAG laser (532 wavelength, 20ns pulse width) in laser sheet tomography. The thickness of the laser sheet which was scattered by the spray was measured to elucidate the effect of the concentration of fluorescent dye in the injected liquid. In the case of water without eosine-Y, multiscattered light-illuminated drops were observed outside of the laser sheet therefore the thickness of the laser sheet increased. However, in the case of water with eosine-Y, there were few drops which were illuminated by the multiscattered light, and only drops which existed within the laser sheet scattered green laser light and emitted the yellow fluorescent light of eosine-Y. 11 refs., 10 figs., 2 tabs.

  17. Spray Calciner/In-Can Melter high-level waste solidification technical manual

    Energy Technology Data Exchange (ETDEWEB)

    Larson, D.E. (ed.)

    1980-09-01

    This technical manual summarizes process and equipment technology developed at Pacific Northwest Laboratory over the last 20 years for vitrification of high-level liquid waste by the Spray Calciner/In-Can Melter process. Pacific Northwest Laboratory experience includes process development and demonstration in laboratory-, pilot-, and full-scale equipment using nonradioactive synthetic wastes. Also, laboratory- and pilot-scale process demonstrations have been conducted using actual high-level radioactive wastes. In the course of process development, more than 26 tonnes of borosilicate glass have been produced in 75 canisters. Four of these canisters contained radioactive waste glass. The associated process and glass chemistry is discussed. Technology areas described include calciner feed treatment and techniques, calcination, vitrification, off-gas treatment, glass containment (the canister), and waste glass chemistry. Areas of optimization and site-specific development that would be needed to adapt this base technology for specific plant application are indicated. A conceptual Spray Calciner/In-Can Melter system design and analyses are provided in the manual to assist prospective users in evaluating the process for plant application, to provide equipment design information, and to supply information for safety analyses and environmental reports. The base (generic) technology for the Spray Calciner/In-Can Melter process has been developed to a point at which it is ready for plant application.

  18. Spray freeze drying of YSZ nanopowder

    Science.gov (United States)

    Raghupathy, Bala P. C.; Binner, J. G. P.

    2012-07-01

    Spray freeze drying of yttria stabilised zirconia nanopowders with a primary particle size of 16 nm has been undertaken using different solids content starting suspensions, with the effect of the latter on the flowability and crushability of the granules being investigated. The flowability and fill density of the granules increased with an increase in the solid content of the starting suspension, whilst the crushability decreased. The powder flowability, measured using a Hall flowmeter and model shoe-die filling tests, showed that the flowability of otherwise poorly flowable nanopowders can be improved to match that of the commercial spray dried submicron powder. The 5.5 vol.% solid content based suspension yielded soft agglomerates whilst a 28 vol.% solid content suspension formed hard agglomerates on spray freeze drying; the granule relics were visible in the fracture surface of the die pressed green compact in the latter case. The increase in granule strength is explained by the reduction in inter-particle distance based on the theories developed by Rumpf and Kendall. The flaw sizes computed using the Kendall model are comparable with those seen in the micrographs of the granule. With an optimum solid content, it is possible to have a granulated nanopowder with reasonable flowability and compactability resulting in homogeneous green bodies with 54 % of theoretical density.

  19. Spray printing of organic semiconducting single crystals.

    Science.gov (United States)

    Rigas, Grigorios-Panagiotis; Payne, Marcia M; Anthony, John E; Horton, Peter N; Castro, Fernando A; Shkunov, Maxim

    2016-11-22

    Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals' size, shape and orientation are controlled by the sheer force generated by the spray droplets' impact onto the antisolvent's surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics.

  20. Spray printing of organic semiconducting single crystals

    Science.gov (United States)

    Rigas, Grigorios-Panagiotis; Payne, Marcia M.; Anthony, John E.; Horton, Peter N.; Castro, Fernando A.; Shkunov, Maxim

    2016-11-01

    Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by combining the advantages of antisolvent crystallization and solution shearing. The crystals' size, shape and orientation are controlled by the sheer force generated by the spray droplets' impact onto the antisolvent's surface. This method demonstrates the feasibility of a spray-on single-crystal organic electronics.

  1. Fundamental Cost Analysis of Cold Spray

    Science.gov (United States)

    Stier, O.

    2014-01-01

    The cost structure of the cold spray (CS) process is analyzed using a generic cost model applicable to all present types of CS systems ("high pressure," "low pressure," KM™, "kinetic spraying," etc.) and kinds of application (coating, restoration, additive manufacturing, near-net forming). The cost model has originally been developed at SIEMENS and is easy to use, while being sufficiently accurate to support decisions. The dependence of the process costs on the gas stagnation properties is discussed. It is shown (i) that high pressure is generally favorable, (ii) that He-N2 blends possess economic potential, and (iii) that He recovery saves costs in high volume production, even when He-N2 blends are used. The cost model allows for the determination of the cost-optimal He concentration of the propellant gas for a given application. CS is, among others, suited to spray bond coatings on gas turbine blades and offers cost-saving potential, as shown in a case study.

  2. Microstructural and Mechanical Properties of Ni-Base Thermal Spray Coatings Deposited by Flame Spraying

    Science.gov (United States)

    Amokrane, Bradai Mohand; Abdelhamid, Sadeddine; Youcef, Mouadji; Abderrahim, Benabbas; Nedjemeddine, Bounar; Ahmed, Mammeri

    2011-10-01

    In this work, two different Ni-base powders, namely, ProXon 21021 (P21) and ProXon 21031 (P31), were sprayed onto a steel substrate 35CrMo4 using a thermal flame spray technique. The morphology and chemical composition of the phases that are present in the powders and coatings were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The hardness and wear resistance of the coatings were investigated. The XRD analysis revealed that the phases present in the coatings are different from the initial powders. In addition, some inhomogeneities such as oxides, porosity, and unmelted particles were observed by SEM. It was found that the P31 spray-coated exhibited higher microhardness, higher wear resistance, and significantly lower friction coefficient in comparison with those of P21 coatings.

  3. Efficient spray-coated colloidal quantum dot solar cells

    KAUST Repository

    Kramer, Illan J.

    2014-11-10

    (Figure Presented). A colloidal quantum dot solar cell is fabricated by spray-coating under ambient conditions. By developing a room-temperature spray-coating technique and implementing a fully automated process with near monolayer control - an approach termed as sprayLD - an electronic defect is eliminated resulting in solar cell performance and statistical distribution superior to prior batch-processed methods along with a hero performance of 8.1%.

  4. Treatment of Rhinitis Sicca Anterior with Ectoine Containing Nasal Spray

    OpenAIRE

    Uwe Sonnemann; Olaf Scherner; Nina Werkhäuser

    2014-01-01

    Objectives. The safety and efficacy of ectoine nasal spray and ectoine nasal spray with dexpanthenol in the treatment of rhinitis sicca were evaluated in two studies. Design and Methods. Two noninterventional observational studies were performed to evaluate the efficacy and safety of a nasal spray containing ectoine (study 1) and ectoine/dexpanthenol (study 2) over a period of two weeks including comparable numbers of patients suffering from rhinitis sicca anterior. Patients and physicians we...

  5. 多喷头组合变量喷药系统的设计与试验%Design and experiment of variable spraying system based on multiple combined nozzles

    Institute of Scientific and Technical Information of China (English)

    徐艳蕾; 包佳林; 付大平; 朱炽阳

    2016-01-01

    At present, in the process of agricultural production, a great use of herbicides have caused the serious pollution of soil environment and the declines of agricultural product quality, and it does not conform to the idea of the sustainable development of agriculture. Variable rate spraying technology is an important development direction to solve this problem. Mostly, the existing variable spraying system changes spraying quantity by adjusting the pressure and by the method of PWM (pulse width modulation) regulating. Pressure regulating mode at the same time of changing nozzle spraying quantity will change the liquid droplets size and spray pattern, and affect the variable spraying operation effect. For the PWM adjustment method, there is the phenomenon that spray status is not continuous at low frequency adjustment, while higher requirements exist for the life and reliability of the electromagnetic valve at high frequency adjustment. And its cost also increases accordingly. The present design of variable spraying system also has the disadvantages of high cost. In order to overcome the shortcomings of existing variable spraying system, this paper designed variable system based on the combined nozzle spraying and had corresponding test analysis. Firstly, the variable-spraying affecting factors model was established. On this basis, this paper designed the variable spraying system of multiple nozzle combination, with single ridge corresponding to the combination of 3 nozzles. High-performance electromagnetic valves were installed in front of each nozzle. By means of controlling the open-close combination of three-way electromagnetic valves, 7 kinds of nozzle spraying combinations were formed. Finally, it achieved 7 kinds of spraying amounts. The designed system could not only control the overall amount of spraying, but also increase regulating range of spraying quantity. In this paper, we designed the pipe of variable spraying system. It mainly included spraying box

  6. Spray Drift Reduction Evaluations of Spray Nozzles Using a Standardized Testing Protocol

    Science.gov (United States)

    2010-07-01

    1998, pp. 194–199. 7 Bilanin, A. J., Teske , M. E., Barry, J. W., and Eckblad, R. B., “AGDISP: The Aircraft Spray Dispersion Model, Code Development and...Experimental Validation,” Trans. ASAE, Vol. 32, 1989, pp. 327–334. 8 Teske , M. E., Thistle, H. W., and Ice, G. G., “Technical Advances in Modeling...Aerially Applied Sprays,” Trans. ASAE, Vol. 46, 2003, pp. 985–996. 9 Teske , M. E. and Thistle, H. W., “A Simulation of Release Height and Wind Speed

  7. Micro-Sized Particle Production of Momordicas sp Extract Using Spray Dryer

    Directory of Open Access Journals (Sweden)

    Maizirwan Mel

    2011-12-01

    Full Text Available Spray drying is the most widely used industrial process involving particle formation and drying. It is highly suited for the continuous production of dry solids in either powder, granulate or agglomerate form from liquid feed-stocks as solutions, emulsions and pump able suspensions. Therefore, spray drying is an ideal process where the end-product must comply with precise quality standards regarding particle size distribution, residual moisture content, bulk density, and particle shape. In this study, Momordica sp extract product has been successfully spray dried into micro scale of powder particle and will be used as plant-based insulin. The process optimized using Taguchi method with four factors and three levels has given a good quality of the product. The average of particle size was obtained at about 11 microns.ABSTRAK: Kering sembur digunakan secara meluas dalam proses industri yang melibatkan pembentukan zarah dan pengeringan. Ia amat sesuai dalam penghasilan pepejal kering secara beterusan dalam bentuk serbuk, butiran atau gumpalan daripada simpanan suapan bendalir sebagai larutan, emulsi dan ampaian boleh dipam. Maka, kering sembur adalah proses yang ideal apabila hasil akhir harus mematuhi piawaian kualiti yang tepat berkaitan dengan pengagihan saiz zarah, kandungan kelengsaan sisa, ketumpatan pukal dan bentuk zarah. Dalam kajian ini, produk ekstrak Momordica sp (dikenali juga sebagai peria katak telah berjaya dikering sembur menjadi serbuk zarah berskala mikro dan akan digunakan sebagai insulin berasaskan tumbuhan. Proses ini dioptimumkan dengan pengunaan kaedah Taguchi empat faktor dan tiga peringkat, agar memberikan hasil produk yang berkualiti. Kadar purata saiz zarah yang terhasil adalah lebih kurang 11 mikron.KEY WORDS: micro-sized, particle, Momordica sp, spray dryer.

  8. Spray cooling characteristics of nanofluids for electronic power devices.

    Science.gov (United States)

    Hsieh, Shou-Shing; Leu, Hsin-Yuan; Liu, Hao-Hsiang

    2015-01-01

    The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle volume fraction and mass flow rate of the liquid on the surface heat flux, including critical heat flux (CHF), are explored. Both steady state and transient data are collected for the two-phase heat transfer coefficient, boiling curve/ cooling history, and the corresponding CHF. The heat transfer removal rate can reach up to 274 W/cm(2) with the corresponding CHF enhancement ratio of 2.4 for the Ag/water nanofluids present at a volume fraction of 0.0075% with a low mass flux of 11.9 × 10(-4) kg/cm(2)s.

  9. Spark Ignition of Monodisperse Fuel Sprays. Ph.D. Thesis

    Science.gov (United States)

    Danis, Allen M.; Cernansky, Nicholas P.; Namer, Izak

    1987-01-01

    A study of spark ignition energy requirements was conducted with a monodisperse spray system allowing independent control of droplet size, equivalent ratio, and fuel type. Minimum ignition energies were measured for n-heptane and methanol sprays characterized at the spark gap in terms of droplet diameter, equivalence ratio (number density) and extent of prevaporization. In addition to sprays, minimum ignition energies were measured for completely prevaporized mixtures of the same fuels over a range of equivalence ratios to provide data at the lower limit of droplet size. Results showed that spray ignition was enhanced with decreasing droplet size and increasing equivalence ratio over the ranges of the parameters studied. By comparing spray and prevaporized ignition results, the existence of an optimum droplet size for ignition was indicated for both fuels. Fuel volatility was seen to be a critical factor in spray ignition. The spray ignition results were analyzed using two different empirical ignition models for quiescent mixtures. Both models accurately predicted the experimental ignition energies for the majority of the spray conditions. Spray ignition was observed to be probabilistic in nature, and ignition was quantified in terms of an ignition frequency for a given spark energy. A model was developed to predict ignition frequencies based on the variation in spark energy and equivalence ratio in the spark gap. The resulting ignition frequency simulations were nearly identical to the experimentally observed values.

  10. Review:Resuspension of wall deposits in spray dryers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Wall deposition occurs in spray dryers when dried or partially dried particles contact and adhere to the walls during operation, thus reducing the yield of product collected. Wall deposits also present a product contamination risk and a fire or explosion risk when spray drying products that oxidize exothermically, such as milk powder. Re-entrainment is the resuspension of spray dryer wall deposits into the main gas stream for collection as product. Literature suggests that the process for re-entrainment of particles from spray dryer wall deposits is strongly dependent on particle size and gas velocity.

  11. Suspension plasma sprayed composite coating using amorphous powder feedstock

    Science.gov (United States)

    Chen, Dianying; Jordan, Eric H.; Gell, Maurice

    2009-03-01

    Al 2O 3-ZrO 2 composite coatings were deposited by the suspension plasma spray process using molecularly mixed amorphous powders. X-ray diffraction (XRD) analysis shows that the as-sprayed coating is composed of α-Al 2O 3 and tetragonal ZrO 2 phases with grain sizes of 26 nm and 18 nm, respectively. The as-sprayed coating has 93% density with a hardness of 9.9 GPa. Heat treatment of the as-sprayed coating reveals that the Al 2O 3 and ZrO 2 phases are homogeneously distributed in the composite coating.

  12. Quality characteristic of spray-drying egg white powders.

    Science.gov (United States)

    Ma, Shuang; Zhao, Songning; Zhang, Yan; Yu, Yiding; Liu, Jingbo; Xu, Menglei

    2013-10-01

    Spray drying is a useful method for developing egg process and utilization. The objective of this study was to evaluate effects on spray drying condition of egg white. The optimized conditions were spraying flow 22 mL/min, feeding temperature 39.8 °C and inlet-air temperature 178.2 °C. Results of sulfydryl (SH) groups measurement indicated conformation structure have changed resulting in protein molecule occur S-S crosslinking phenomenon when heating. It led to free SH content decreased during spray drying process. There was almost no change of differential scanning calorimetry between fresh egg white and spray-drying egg white powder (EWP). For a given protein, the apparent SH reactivity is in turn influenced by the physico-chemical characteristics of the reactant. The phenomenon illustrated the thermal denaturation of these proteins was unrelated to their free SH contents. Color measurement was used to study browning level. EWP in optimized conditions revealed insignificant brown stain. Swelling capacity and scanning electron micrograph both proved well quality characteristic of spray-drying EWP. Results suggested spray drying under the optimized conditions present suitable and alternative method for egg processing industrial implementation. Egg food industrialization needs new drying method to extend shelf-life. The purpose of the study was to provide optimal process of healthy and nutritional instant spray-drying EWP and study quality characteristic of spray-drying EWP.

  13. RESEARCH ON THE RECONDITIONING METAL SPRAYING ULTRASONIC FIELDS

    Directory of Open Access Journals (Sweden)

    GHEORGHE AMZA

    2015-05-01

    Full Text Available The paper presents research on process optimization of metal spraying activated ultrasonic fields. In order to optimize process parameters are selected metal spraying flame and flame wire electrode with and without ultrasonic activation. It then makes an analysis of the chemical composition resulting filler material, line and base material for more couplers materials. It also presents the resulting the couple main functional properties for metal oxy-fuel flame spraying and wire electrode with and without activating ultrasonic wire electrode to highlight the advantages of metal spraying process in ultrasonic field.

  14. Numerical studies of spray combustion processes of palm oil biodiesel and diesel fuels using reduced chemical kinetic mechanisms

    KAUST Repository

    Kuti, Olawole

    2014-04-01

    Spray combustion processes of palm oil biodiesel (PO) and conventional diesel fuels were simulated using the CONVERGE CFD code. Thermochemical and reaction kinetic data (115 species and 460 reactions) by Luo et al. (2012) and Lu et al. (2009) (68 species and 283 reactions) were implemented in the CONVERGE CFD to simulate the spray and combustion processes of the two fuels. Tetradecane (C14H30) and n- heptane (C7H 16) were used as surrogates for diesel. For the palm biodiesel, the mixture of methyl decanoate (C11H20O2), methyl-9-decenoate (C11H19O2) and n-heptane was used as surrogate. The palm biodiesel surrogates were combined in proportions based on the previous GC-MS results for the five major biodiesel components namely methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linolenate. The Favre-Averaged Navier Stokes based simulation using the renormalization group (RNG) k-ε turbulent model was implemented in the numerical calculations of the spray formation processes while the SAGE chemical kinetic solver is used for the detailed kinetic modeling. The SAGE chemical kinetic solver is directly coupled with the gas phase calculations by renormalization group (RNG) k-ε turbulent model using a well-stirred reactor model. Validations of the spray liquid length, ignition delay and flame lift-off length data were performed against previous experimental results. The simulated liquid length, ignition delay and flame lift-off length were validated at an ambient density of 15kg/m3, and injection pressure conditions of 100, 200 and 300 MPa were utilized. The predicted liquid length, ignition delay and flame lift-off length agree with the trends obtained in the experimental data at all injection conditions. Copyright © 2014 SAE International.

  15. 75 FR 49487 - Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray

    Science.gov (United States)

    2010-08-13

    ... AGENCY Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray AGENCY: Environmental Protection... period for the draft document ``Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray'' (EPA.... ] ADDRESSES: The draft ``Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray'' is available...

  16. Sensory aroma characteristics of alcalase hydrolyzed rice bran protein concentrate as affected by spray drying and sugar addition.

    Science.gov (United States)

    Arsa, Supeeraya; Theerakulkait, Chockchai

    2015-08-01

    The sensory aroma characteristics of alcalase hydrolyzed rice bran protein concentrate as affected by spray drying and sugar addition were investigated. Rice bran protein concentrate (RBPC) was hydrolyzed by alcalase. Sucrose, glucose or fructose was added to the liquid rice bran protein hydrolysate (LRBPH) and subsequently spray dried. The sensory aroma intensities of the hydrolysates were evaluated. Results showed that after spray drying, the rice bran protein concentrate powder (RBPC-P) had higher sweet and cocoa-like aroma intensities than RBPC (p ≤ 0.05) and hydrolyzed rice bran protein powder (HRBPP) had higher milk powder-like aroma intensities than LRBPH (p ≤ 0.05). The sweet, cocoa-like and milk powder-like aroma intensities in hydrolyzed rice bran protein powder with fructose addition (HRBPP-F) were significantly higher (p ≤ 0.05) than those of hydrolyzed rice bran protein powder with sucrose or glucose addition (HRBPP-S or HRBPP-G). HRBPP-F had the highest overall aroma liking score. These results also indicate that spray drying and sugar addition could improve the sensory aroma characteristics of alcalase hydrolyzed RBPC.

  17. Spray-dried powders improve the controlled release of antifungal tioconazole-loaded polymeric nanocapsules compared to with lyophilized products

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Roseane Fagundes [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS, 97105-900 (Brazil); Motta, Mariana Heldt [Curso de Farmácia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS, 97105-900 (Brazil); Härter, Andréia Pisching Garcia; Flores, Fernanda Cramer [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS, 97105-900 (Brazil); Beck, Ruy Carlos Ruver [Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Av. Ipiranga, 2752, Porto Alegre, RS, 90610-000 (Brazil); Schaffazick, Scheila Rezende [Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal de Santa Maria, Av. Roraima, 1000, Santa Maria, RS, 97105-900 (Brazil); and others

    2016-02-01

    This work aimed to obtain solid formulations from polymeric nanocapsules and nanoemulsions containing tioconazole, a broad spectrum antifungal drug. Two dehydration methods were used: spray-drying and freeze-drying, using lactose as adjuvant (10%, w/v). The liquid formulations had a mean particle size around 206 nm and 182 nm for nanocapsules and nanoemulsions, respectively, and an adequate polydispersity index. Tioconazole content was close to the theoretical amount (1.0 mg/mL). After drying, the content ranged between 98 and 102% with a mean nanometric size of the dried products after redispersion. Scanning electron microscopy showed that the particles are rounded, sphere-shaped for the dried products obtained by spray-drying, and shapeless and irregular shapes for those obtained by freeze-drying. In the microbiological evaluation, all dried products remained active against the yeast Candida albicans when compared to the original systems. The dried products obtained by spray-drying from nanocapsules presented better control of the tioconazole release when compared to the freeze-drying products. - Highlights: • Polymeric nanocapsule suspensions containing tioconazole were submitted to spray-drying and freeze-drying. • Dried products from nanocapsule suspensions were stable for 30 days. • Release studies showed that the dried products presented greater control of drug release compared to the original suspension.

  18. Market Liquidity and Funding Liquidity

    OpenAIRE

    Brunnermeier, Markus K; Lasse Heje Pedersen

    2007-01-01

    We provide a model that links an asset's market liquidity - i.e., the ease with which it is traded - and traders' funding liquidity - i.e., the ease with which they can obtain funding. Traders provide market liquidity, and their ability to do so depends on their availability of funding. Conversely, traders' funding, i.e., their capital and the margins they are charged, depend on the assets' market liquidity. We show that, under certain conditions, margins are destabilizing and market liquidit...

  19. Market Liquidity and Funding Liquidity

    OpenAIRE

    Markus K. Brunnermeier; Lasse Heje Pedersen

    2007-01-01

    We provide a model that links an asset's market liquidity - i.e., the ease with which it is traded - and traders' funding liquidity - i.e., the ease with which they can obtain funding. Traders provide market liquidity, and their ability to do so depends on their availability of funding. Conversely, traders' funding, i.e., their capital and the margins they are charged, depend on the assets' market liquidity. We show that, under certain conditions, margins are destabilizing and market liquidit...

  20. Field-assisted paper spray mass spectrometry for the quantitative evaluation of imatinib levels in plasma.

    Science.gov (United States)

    D'Aronco, Sara; Calandra, Eleonora; Crotti, Sara; Toffoli, Giuseppe; Marangon, Elena; Posocco, Bianca; Traldi, Pietro; Agostini, Marco

    Drug levels in patients' bloodstreams vary among individuals and consequently therapeutic drug monitoring (TDM) is fundamental to controlling the effective therapeutic range. For TDM purposes, different analytical approaches have been used, mainly based on immunoassay, liquid chromatography- ultraviolet, liquid chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. More recently a matrix-assisted laser desorption/ionisation method has been proposed for the determination of irinotecan levels in the plasma of subjects under therapy and this method has been cross- validated by comparison with data achieved by LC-MS/MS. However, to reach an effective point-of-care monitoring of plasma drug concentrations, a TDM platform technology for fast, accurate, low-cost assays is required. In this frame, recently the use of paper spray mass spectrometry, which is becoming a popular and widely employed MS method, has been proposed. In this paper we report the results obtained by the development of a paper spray-based method for quantitative analysis in plasma samples of imatinib, a new generation of anticancer drug. Preliminary experiments showed that poor sensitivity, reproducibility and linear response were obtained by the "classical" paper spray set-up. In order to achieve better results, it was thought of interest to operate in presence of a higher and more homogeneous electrical field. For this aim, a stainless steel needle connected with the high voltage power supply was mounted below the paper triangle. Furthermore, in order to obtain valid quantitative data, we analysed the role of the different equilibria participating to the phenomena occurring in paper spray experiments, depending either on instrumental parameters or on the chemical nature of analyte and solvents. A calibration curve was obtained by spiking plasma samples containing different amounts of imatinib (1) with known amounts of deuterated imatinib (1d3) as

  1. Investigation of Critical Burning of Fuel Droplets. [of liquid rocket propellant

    Science.gov (United States)

    Chanin, S. P.; Shearer, A. J.; Faeth, G. M.

    1976-01-01

    An earlier analysis for the combustion response of a liquid monopropellant strand (hydrazine) was extended to consider individual droplets and sprays. While small drops gave low or negative response, large droplets provided response near unity at low frequencies, with the response declining at frequencies greater than the characteristic liquid phase frequency. Temperature gradients in the liquid phase resulted in response peaks greater than unity. A second response peak was found for large drops which corresponded to gas phase transient effects. Spray response was generally reduced from the response of the largest injected droplet, however, even a small percentage of large droplets can yield appreciable response. An apparatus was designed and fabricated to allow observation of bipropellant fuel spray combustion at elevated pressures. A locally homogeneous model was developed to describe this combustion process which allows for high pressure phenomena associated with the thermodynamic critical point.

  2. A two-angle far-field microscope imaging technique for spray flows

    Science.gov (United States)

    Kourmatzis, Agisilaos; Pham, Phuong X.; Masri, Assaad R.

    2017-03-01

    Backlight imaging is frequently used for the visualization of multiphase flows, where with appropriate microscope lenses, quantitative information on the spray structure can be attained. However, a key issue resides in the nature of the measurement which relies on a single viewing angle, hence preventing imaging of all liquid structures and features, such as those located behind other fragments. This paper presents results from an extensive experimental study aimed as a step forward towards resolving this problem by using a pair of high speed cameras oriented at 90 degrees to each other, and synchronized to two high-speed diode lasers. Both cameras are used with long distance microscope lenses. The images are processed as pairs allowing for identification and classification of the same liquid structure from two perspectives at high temporal (5 kHz) and spatial resolution (∼3 μm). Using a controlled mono-disperse spray, simultaneous, time-resolved visualization of the same spherical object being focused on one plane while de-focused on the other plane 90 degrees to the first has allowed for a quantification of shot-to-shot defocused size measurement error. An extensive error analysis is performed for spheroidal structures imaged from two angles and the dual angle technique is extended to measure the volume of non-spherical fragments for the first time, by ‘discretising’ a fragment into a number of constituent ellipses. Error analysis is performed based on measuring the known volumes of solid arbitrary shapes, and volume estimates were found to be within  ∼11% of the real volume for representative ‘ligament-like’ shapes. The contribution concludes by applying the ellipsoidal method to a real spray consisting of multiple non-spherical fragments. This extended approach clearly demonstrates potential to yield novel volume weighted quantities of non-spherical objects in turbulent multiphase flow applications.

  3. Preparation of cellulose based microspheres by combining spray coagulating with spray drying.

    Science.gov (United States)

    Wang, Qiao; Fu, Aiping; Li, Hongliang; Liu, Jingquan; Guo, Peizhi; Zhao, Xiu Song; Xia, Lin Hua

    2014-10-13

    Porous microspheres of regenerated cellulose with size in range of 1-2 μm and composite microspheres of chitosan coated cellulose with size of 1-3 μm were obtained through a two-step spray-assisted approach. The spray coagulating process must combine with a spray drying step to guarantee the formation of stable microspheres of cellulose. This approach exhibits the following two main virtues. First, the preparation was performed using aqueous solution of cellulose as precursor in the absence of organic solvent and surfactant; Second, neither crosslinking agent nor separated crosslinking process was required for formation of stable microspheres. Moreover, the spray drying step also provided us with the chance to encapsulate guests into the resultant cellulose microspheres. The potential application of the cellulose microspheres acting as drug delivery vector has been studied in two PBS (phosphate-buffered saline) solution with pH values at 4.0 and 7.4 to mimic the environments of stomach and intestine, respectively.

  4. Spray-coating process in preparing PTFE-PPS composite super-hydrophobic coating

    Directory of Open Access Journals (Sweden)

    Rui Weng

    2014-03-01

    Full Text Available In order to improve the performance of a liquid-floated rotor micro-gyroscope, the resistance of the moving interface between the rotor and the floating liquid must be reduced. Hydrophobic treatment can reduce the frictional resistance between such interfaces, therefore we proposed a method to prepare a poly-tetrafluoroethylene (PTFE-poly-phenylene sulphide (PPS composite super-hydrophobic coating, based on a spraying process. This method can quickly prepare a continuous, uniform PTFE-PPS composite super-hydrophobic surface on a 2J85 material. This method can be divided into three steps, namely: pre-treatment; chemical etching; and spraying. The total time for this is around three hours. When the PTFE concentration is 4%, the average contact angle of the hydrophobic coating surface is 158°. If silicon dioxide nanoparticles are added, this can further improve the adhesion and mechanical strength of the super-hydrophobic composite coating. The maximum average contact angle can reach as high as 164° when the mass fraction of PTFE, PPS and silicon dioxide is 1:1:1.

  5. Efficacy of Selected Insecticide Sprays and Aerosols against the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae

    Directory of Open Access Journals (Sweden)

    Changlu Wang

    2016-01-01

    Full Text Available We evaluated the residual efficacy of four liquid sprays and four ready-to-use aerosols that are commonly used in the U.S. against a field-collected bed bug, Cimex lectularius L., strain with moderate resistance level to pyrethroids. The four liquid sprays were: Tandem (0.1% thiamethoxam, 0.03% lambda-cyhalothrin, Temprid SC (0.05% imidacloprid, 0.025% cyfluthrin, Transport GHP (0.05% acetamiprid, 0.06% bifenthrin, and Demand CS (0.03% lambda-cyhalothrin. The four aerosols were: Alpine (0.5% dinotefuran, Bedlam (0.4% sumithrin, 1.6% MGK 264, Bedlam Plus (0.4% sumithrin, 1% MGK 264, 0.05% imidacloprid, and Phantom (0.5% chlorfenapyr. Bed bugs were confined for 4 h to treated substrates (aged 24 h. Four substrates were tested: fabric, unpainted wood, painted wood, and vinyl. Bedlam, Demand CS, and Temprid SC resulted in ≤70% mortality on all tested substrates. Among the other five products, substrate type significantly affected their residual efficacy, except for Transport GHP, which caused ≥89.7% mortality regardless of the substrate. The effect of exposure time (5 min, 4 h, and 24 h on the efficacy of Transport GHP and Phantom aerosol also was evaluated. A 4 h continuous exposure to Phantom aerosol or Transport GHP residue caused similar mortality to 24 h exposure and higher mortality than 5 min exposure.

  6. Efficacy of Selected Insecticide Sprays and Aerosols against the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae)

    Science.gov (United States)

    Wang, Changlu; Singh, Narinderpal; Zha, Chen; Cooper, Richard

    2016-01-01

    We evaluated the residual efficacy of four liquid sprays and four ready-to-use aerosols that are commonly used in the U.S. against a field-collected bed bug, Cimex lectularius L., strain with moderate resistance level to pyrethroids. The four liquid sprays were: Tandem (0.1% thiamethoxam, 0.03% lambda-cyhalothrin), Temprid SC (0.05% imidacloprid, 0.025% cyfluthrin), Transport GHP (0.05% acetamiprid, 0.06% bifenthrin), and Demand CS (0.03% lambda-cyhalothrin). The four aerosols were: Alpine (0.5% dinotefuran), Bedlam (0.4% sumithrin, 1.6% MGK 264), Bedlam Plus (0.4% sumithrin, 1% MGK 264, 0.05% imidacloprid), and Phantom (0.5% chlorfenapyr). Bed bugs were confined for 4 h to treated substrates (aged 24 h). Four substrates were tested: fabric, unpainted wood, painted wood, and vinyl. Bedlam, Demand CS, and Temprid SC resulted in ≤70% mortality on all tested substrates. Among the other five products, substrate type significantly affected their residual efficacy, except for Transport GHP, which caused ≥89.7% mortality regardless of the substrate. The effect of exposure time (5 min, 4 h, and 24 h) on the efficacy of Transport GHP and Phantom aerosol also was evaluated. A 4 h continuous exposure to Phantom aerosol or Transport GHP residue caused similar mortality to 24 h exposure and higher mortality than 5 min exposure. PMID:26840334

  7. Efficacy of Selected Insecticide Sprays and Aerosols against the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae).

    Science.gov (United States)

    Wang, Changlu; Singh, Narinderpal; Zha, Chen; Cooper, Richard

    2016-01-29

    We evaluated the residual efficacy of four liquid sprays and four ready-to-use aerosols that are commonly used in the U.S. against a field-collected bed bug, Cimex lectularius L., strain with moderate resistance level to pyrethroids. The four liquid sprays were: Tandem (0.1% thiamethoxam, 0.03% lambda-cyhalothrin), Temprid SC (0.05% imidacloprid, 0.025% cyfluthrin), Transport GHP (0.05% acetamiprid, 0.06% bifenthrin), and Demand CS (0.03% lambda-cyhalothrin). The four aerosols were: Alpine (0.5% dinotefuran), Bedlam (0.4% sumithrin, 1.6% MGK 264), Bedlam Plus (0.4% sumithrin, 1% MGK 264, 0.05% imidacloprid), and Phantom (0.5% chlorfenapyr). Bed bugs were confined for 4 h to treated substrates (aged 24 h). Four substrates were tested: fabric, unpainted wood, painted wood, and vinyl. Bedlam, Demand CS, and Temprid SC resulted in ≤70% mortality on all tested substrates. Among the other five products, substrate type significantly affected their residual efficacy, except for Transport GHP, which caused ≥89.7% mortality regardless of the substrate. The effect of exposure time (5 min, 4 h, and 24 h) on the efficacy of Transport GHP and Phantom aerosol also was evaluated. A 4 h continuous exposure to Phantom aerosol or Transport GHP residue caused similar mortality to 24 h exposure and higher mortality than 5 min exposure.

  8. Suspensions Plasma Spraying of Ceramics with Hybrid Water-Stabilized Plasma Technology

    Science.gov (United States)

    Musalek, Radek; Medricky, Jan; Tesar, Tomas; Kotlan, Jiri; Pala, Zdenek; Lukac, Frantisek; Chraska, Tomas; Curry, Nicholas

    2016-12-01

    Technology of water-stabilized plasma torch was recently substantially updated through introduction of a so-called hybrid concept that combines benefits of water stabilization and gas stabilization principles. The high-enthalpy plasma provided by the WSP-H ("hybrid") torch may be used for thermal spraying of powders as well as liquid feedstocks with high feed rates. In this study, results from three selected experiments with suspension plasma spraying with WSP-H technology are presented. Possibility of deposition of coatings with controlled microstructures was demonstrated for three different ceramics (YSZ—yttria-stabilized zirconia, YAG—yttrium aluminum garnet and Al2O3) introduced into ethanol-based suspensions. Shadowgraphy was used for optimization of suspension injection and visualization of the liquid fragmentation in the plasma jet. Coatings were deposited onto substrates attached to the rotating carousel with integrated temperature monitoring and air cooling, which provided an excellent reproducibility of the deposition process. Deposition of columnar-like YSZ and dense YAG and Al2O3 coatings was successfully achieved. Deposition efficiency reached more than 50%, as evaluated according to EN ISO 17 836 standard.

  9. HVOF- and HVAF-Sprayed Cr3C2-NiCr Coatings Deposited from Feedstock Powders of Spherical Morphology: Microstructure Formation and High-Stress Abrasive Wear Resistance Up to 800 °C

    Science.gov (United States)

    Janka, L.; Norpoth, J.; Trache, R.; Thiele, S.; Berger, L.-M.

    2017-08-01

    Chromium carbide-based coatings are commonly applied to protect surfaces against wear at high temperatures. This work discusses the influence of feedstock powder and spray torch selection on the microstructure and high-stress abrasion resistance of thermally sprayed Cr3C2-NiCr coatings. Four commercial feedstock powders with spherical morphology and different microstructures were deposited by different high-velocity spray processes, namely third-generation gas- and liquid-fueled HVOF torches and by the latest generation HVAF torch. The microstructures of the coatings were studied in the as-sprayed state and after various heat treatments. The high-stress abrasion resistance of as-sprayed and heat-treated coatings was tested at room temperature and at 800 °C. The study reveals that the selection of the spray torch mainly affects the room temperature abrasion resistance of the as-sprayed coatings, which is due to differences in the embrittlement of the binder phase generated by carbide dissolution. At elevated temperatures, precipitation and growth of secondary carbides yields a fast equalization of the various coatings microstructures and wear properties.

  10. Comparison of a laboratory and a production coating spray gun with respect to scale-up.

    Science.gov (United States)

    Mueller, Ronny; Kleinebudde, Peter

    2007-01-19

    A laboratory spray gun and a production spray gun were investigated in a scale-up study. Two Schlick spray guns, which are equipped with a new antibearding cap, were used in this study. The influence of the atomization air pressure, spray gun-to tablet bed distance, polymer solution viscosity, and spray rate were analyzed in a statistical design of experiments. The 2 spray guns were compared with respect to the spray width and height, droplet size, droplet velocity, and spray density. The droplet size, velocity, and spray density were measured with a Phase Doppler Particle Analyzer. A successful scale-up of the atomization is accomplished if similar droplet sizes, droplet velocities, and spray densities are achieved in the production scale as in the laboratory scale. This study gives basic information for the scale-up of the settings from the laboratory spray gun to the production spray gun. Both spray guns are highly comparable with respect to the droplet size and velocity. The scale-up of the droplet size should be performed by an adjustment of the atomization air pressure. The scale-up of the droplet velocity should be performed by an adjustment of the spray gun to tablet bed distance. The presented statistical model and surface plots are convenient and powerful tools for scaling up the spray settings if the spray gun is changed from laboratory spray gun to the production spray gun.

  11. Replacement of corrosion protection chromate primers and paints used in cryogenic applications on the Space Shuttle with wire arc sprayed aluminum coatings

    Science.gov (United States)

    Daniel, R. L.; Sanders, H. L.; Zimmerman, F. R.

    1995-01-01

    With the advent of new environmental laws restricting volatile organic compounds and hexavalent chrome emissions, 'environmentally safe' thermal spray coatings are being developed to replace the traditional corrosion protection chromate primers. A wire arc sprayed aluminum coating is being developed for corrosion protection of low pressure liquid hydrogen carrying ducts on the Space Shuttle Main Engine. Currently, this hardware utilizes a chromate primer to provide protection against corrosion pitting and stress corrosion cracking induced by the cryogenic operating environment. The wire are sprayed aluminum coating has been found to have good potential to provide corrosion protection for flight hardware in cryogenic applications. The coating development, adhesion test, corrosion test and cryogenic flexibility test results will be presented.

  12. Synthesis of nanocrystalline Cu{sub 2}ZnSnS{sub 4} thin films grown by the spray-pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Chandel, Tarun, E-mail: tarunchandel777@yahoo.com; Singh, Joginder; Rajaram, P. [School of Studies in Physics, Jiwaji University, Gwalior (MP), India-474011 (India)

    2015-08-28

    Spray pyrolysis was used to deposit Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films on soda lime glass substrates at 300 °C. Aqueous solutions of copper chloride, zinc chloride, stannous chloride and thiourea were mixed together to form the spray liquid. The sprayed films were annealed under vacuum at 350 °C, 400 °C and 450 °C. Structural and optical characterization was performed on the CZTS films using X-ray diffraction (XRD) and UV-VIS spectrophotometry. XRD results indicate that the films are single phase nanocrystalline CZTS. Optical studies show that the optical gap values are 1.44 eV for the as-grown film and 1.46 eV, 1.48 eV and 1.49 eV for the films annealed at 350 °C, 400 °C and 450 °C, respectively.

  13. Experimental Investigation of Characteristics of a Double-Base Swirl Injector in a Liquid Rocket Propellant Engine

    Directory of Open Access Journals (Sweden)

    Fathollah OMMI

    2009-07-01

    Full Text Available In this work the fundamentals of swirl injector calculation is investigated and new design procedure is proposed. The design method for double-base liquid-liquid injectors is presented based on this theory and experimental results. Then special conditions related to double-based liquid-liquid injectors are studied and the corresponding results are applied in design manipulation. The behaviour of injector in various performing conditions is studied, and the design procedure is presented based on obtained results. A computer code for designing the injector is proposed. Based on this code, four injectors are manufactured. A specialized laboratory was setup for the measurement of macroscopic spray characteristics under different pressure such as homogeneous droplet distribution, spray angle, swirl effect. Finally, through PDA cold test, the microscopic characteristics of injectors spray are also obtained and measured. The results, which will be explained in detail, are satisfactory.

  14. Generalized Liquid Film Atomization Theory

    Institute of Scientific and Technical Information of China (English)

    HeraldoS.Couto; DemetrioBastos-Netto

    2000-01-01

    The increase of the fuel burning area required by most practical combustion processes in order to guarantee the minimum energy density rate release for their start up and operation is normally achieved by the proper choice among several existing types of atomizers.For instance.impinging and multi-impinging jets atomizers are used in rocket combustion chambers.while splash-plate atomizers find their use when wall film cooling is required.Pressure swirl atomizers,either of simplex or duplex kind,along with Y-jet or SPider Jet atomizers are used in industrial applications and in turbine combustion chambers.Notice.however,that all the types of atomizing devices listed above have one point in common:they are of pre-filming kind.i.e.,befor the droplet spray is generated,a liquid film is formed.This liquid film is broken into unstable ligaments which contract under the action of surface tension forming the droplets.Once the film thickness is estimated.the droplets'SMD(Sauter Mean Diameter)can be calculated.yielding a crucial prameter for the combustion chamber design.However,although this mechanism of droplet fromation has been under study for several decades.most of the available results.are based upon experimental data.valid for a special type of atomizer under the given sepcific conditions only.This work offers a generalized theory for theoretically estimating the SMD of sprays generated by liquid pre-filming atomizers in gereral.

  15. High-speed, two-dimensional synchrotron white-beam x-ray radiography of spray breakup and atomization.

    Science.gov (United States)

    Halls, Benjamin R; Radke, Christopher D; Reuter, Benjamin J; Kastengren, Alan L; Gord, James R; Meyer, Terrence R

    2017-01-23

    High-speed, two-dimensional synchrotron x-ray radiography and phase-contrast imaging are demonstrated in propulsion sprays. Measurements are performed at the 7-BM beamline at the Advanced Photon Source user facility at Argonne National Laboratory using a recently developed broadband x-ray white beam. This novel enhancement allows for high speed, high fidelity x-ray imaging for the community at large. Quantitative path-integrated liquid distributions and spatio-temporal dynamics of the sprays were imaged with a LuAG:Ce scintillator optically coupled to a high-speed CMOS camera. Images are collected with a microscope objective at frame rates of 20 kHz and with a macro lens at 120 kHz, achieving spatial resolutions of 12 μm and 65 μm, respectively. Imaging with and without potassium iodide (KI) as a contrast-enhancing agent is compared, and the effects of broadband attenuation and spatial beam characteristics are determined through modeling and experimental calibration. In addition, phase contrast is used to differentiate liquid streams with varying concentrations of KI. The experimental approach is applied to different spray conditions, including quantitative measurements of mass distribution during primary atomization and qualitative visualization of turbulent binary fluid mixing.

  16. Application of laser assisted cold spraying process for metal deposition

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2014-02-01

    Full Text Available Laser assisted cold spraying (LACS) process is a hybrid technique that uses laser and cold spray to deposit solid powders on metal substrates. For bonding to occur, the particle velocities must be supersonic which are achieved by entraining...

  17. Tableting properties of an improved spray-dried lactose

    NARCIS (Netherlands)

    Rassu, G.; Eissens, A. C.; Bolhuis, G. K.

    2006-01-01

    Spray-dried lactose is one of the most widely used filler-binders for direct compaction. The compactibility is a function of both primary particle size and the presence of amorphous lactose. Commercially available spray-dried lactose contains 15-20% amorphous lactose and 80-85% alpha-lactose monohyd

  18. Dust Reduction in Broiler Houses by Spraying Rapeseed Oil

    NARCIS (Netherlands)

    Aarnink, A.J.A.; Harn, van J.; Hattum, van T.G.; Zhao, Y.; Ogink, N.W.M.

    2011-01-01

    The effect of spraying rapeseed oil on the reduction of dust and ammonia concentrations and emissions, and on animal parameters was investigated in a dose-response study in a broiler house during three growing periods in four (round 1) or five rooms (rounds 2 and 3). The spraying rates varied per ro

  19. Comparison of three fungicide spray advisories for lettuce downy mildew

    NARCIS (Netherlands)

    Wu, B.M.; Subbarao, K.V.; Bruggen, van A.H.C.; Koike, S.T.

    2001-01-01

    Lettuce growers in coastal California have relied mainly on protective fungicide sprays to control downy mildew. Thus, timing of sprays before infection is critical for optimal results. A leaf-wetness-driven, infection-based advisory system, previously developed, did not always perform satisfactoril

  20. Screening and spray drying of enzymes and probiotics

    NARCIS (Netherlands)

    Schutyser, M.A.I.; Perdana, J.A.; Fox, M.B.

    2013-01-01

    Many food ingredients, such as enzymes and probiotics, are spray dried to provide a longer shelf life. A major hurdle when applying spray drying is the extensive optimisa tion required for formulation and drying conditions to obtain powders of acceptable quality. Therefore, a high-throughput screeni

  1. The preparation of steatite suspension for spray drying

    Science.gov (United States)

    Jirousek, L.; Spicak, K.

    1983-01-01

    Liquifying agents were investigated for preparation of highly concentrated steatite suspensions which are to be spray-dried. Organic additives for improving the molding properties and strength of green compacts are described. Demands on properties of the spray-dried granules are defined with regard to shrinkage of the molded compacts.

  2. Single droplet analysis for spray drying of foods

    NARCIS (Netherlands)

    Perdana, J.A.

    2013-01-01

    Many food ingredients, such as enzymes and probiotics, are spray dried to provide shelf-life. Major hurdle to apply spray drying is the lack of scientific insight on the inactivation mechanisms of components and the extensive optimization required for formulation and drying conditions to obtain powd

  3. 9 CFR 590.540 - Spray process drying facilities.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Spray process drying facilities. 590.540 Section 590.540 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF..., Processing, and Facility Requirements § 590.540 Spray process drying facilities. (a) Driers shall be of...

  4. Digital Image Processing application to spray and flammability studies

    Science.gov (United States)

    Hernan, M. A.; Parikh, P.; Sarohia, V.

    1985-01-01

    Digital Image Processing has been integrated into a new technique for measurements of fuel spray characteristics. The advantages of this technique are: a wide dynamic range of droplet sizes, accounting for nonspherical droplet shapes not possible with other spray assessment techniques. Finally, the technique has been applied to the study of turbojet engine fuel nozzle atomization performance with Jet A and antimisting fuel.

  5. Liquid Ventilation

    Directory of Open Access Journals (Sweden)

    Qutaiba A. Tawfic

    2011-01-01

    Full Text Available Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future. Keywords: Liquid ventilation; perfluorochemicals; perfluorocarbon; respiratory distress; surfactant.

  6. Modeling of air-droplet interaction, substrate melting and coating buildup in thermal spraying

    Science.gov (United States)

    Wei, Guanghua

    particle feeding velocity. In this thesis, the level set method is used to study the interaction between the droplet and the surrounding air. The level set function is used to track the deformation of the free surface. The capability of this model on accurately and efficiently simulating the droplet deformation and oscillation is demonstrated. The droplet deformation during in-flight caused by the air-droplet interaction and the droplet-substrate interaction are considered here. Particles with different surface tension and morphologies are studied as well. Droplet substrate interaction is studied to understand the substrate melting behavior. A numerical model is developed to investigate the droplet solidification, substrate melting and re-solidification. A dimensionless parameter, "temperature factor", is proposed from analysis and it can be used as an indicator to predict whether substrate melting will occur for a certain combination of the droplet and substrate. This parameter can be correlated with the maximum melting depth of the substrate. The possibility of heating up the substrate by plasma flame, and attaching a temperature-control device on the backside of the substrate to achieve substrate melting is studied. The substrate front surface temperature can be controlled at a sufficient high temperature. With additional heating from superheated molten droplets and the latent heat of droplet solidification, a thin liquid layer of the substrate can be obtained and epitaxy growth of the splats is possible. This could expand thermal spray technology to the applications of semiconductor and solar energy, both of which need epitaxy crystal with big sizes. To better control the existing thermal spray process, it is important to develop the quantitative relationships between spray parameters and coating characteristics. Until recently, the simulation studies have been focused on two-dimensional models and prediction of the cross-section structure of deposited layers; although

  7. Spray drying of fenofibrate loaded nanostructured lipid carriers

    DEFF Research Database (Denmark)

    Xia, Dengning; Shrestha, Neha; van de Streek, Jacco

    2016-01-01

    content of dry powder decreased with an increase in the ratio of mannitol to trehalose. Lipid nanoparticles were able to retain the drug incorporation and the prolonged drug release profile after spray drying. The experimental model was robust, and suggested that spray drying is a viable technique......The conversion of aqueous dispersion of nanostructured lipid carriers (NLCs) into dry powder by spray drying could be a useful approach to render NLCs with better physical chemical stability than the aqueous dispersion. In this study, aqueous NLC dispersion containing fenofibrate was converted...... into dry, easily reconstitutable powder using spray drying. A central composite face centered design (CCFD) was used to investigate the influence of the ratio of lipid to protectant (mannitol and trehalose) and crystallinity of spray-dried powder on the particle size, yield and residual moisture content...

  8. Equations of two-phase flow in spray chamber

    Institute of Scientific and Technical Information of China (English)

    李新禹; 张志红; 金星; 徐杰

    2009-01-01

    The downstream water-air heat and moisture transfer system in a moving coordinate was studied. The relationship between the diameter of the misted droplets and the spray pressure was determined. Based on the theory of the relative velocity,the two-phase flow mode of the spray chamber and the efficiency equation for heat and moisture exchange were established. Corrections were carried out for the efficiency equation with spray pressure of 157 kPa. The results show that the pressure plays an important part in determining the efficiency of heat and moisture exchange. When the spray pressure is less than 157 kPa,better coincidence is noticed between the theoretical analysis and the test results with the error less than 6%. Greater error will be resulted in the case when the spray pressure is beyond 157 kPa. After the correction treatment,the coincidence between the theoretical and the experimental results is greatly improved.

  9. Plasma spray for forming nanostructured thermal barrier coatings

    Institute of Scientific and Technical Information of China (English)

    LIN; Feng; JIANG; Xian-liang; YU; Yue-guang; ZENG; Ke-li; REN; Xian-jing

    2005-01-01

    Nanocrystalline powders of yttrium partially stabilized zirconia (YPSZ) are reprocessed into agglomerated feedstocks for plasma spraying thermal barrier coatings (TBCs), using the methods of ball milling, slurry dispersion, spray drying, and heat treatment. Atmospheric plasma is used to spray the agglomerated nanocrystalline particle feedstocks and coatings were deposited on the substrate of Ni-based superalloy. Scanning electron microscopy (SEM) is used to examine the morphology and cross-section of the agglomerated feedstocks and the free-section and cross-section of the nanostructured TBCs. Experimental results show that the agglomerated nanocrystalline particles are spherical and dense. Unlike conventional plasma-sprayed coatings, the micron/nano/micron sandwich structure can be found in the nanostructured YPSZ coatings deposited by atmospheric plasma spraying.

  10. Experimental Analysis of Tensile Mechanical Properties of Sprayed FRP

    Directory of Open Access Journals (Sweden)

    Zhao Yang

    2016-01-01

    Full Text Available To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.

  11. The role of drop velocity in statistical spray description

    Science.gov (United States)

    Groeneweg, J. F.; El-Wakil, M. M.; Myers, P. S.; Uyehara, O. A.

    1978-01-01

    The justification for describing a spray by treating drop velocity as a random variable on an equal statistical basis with drop size was studied experimentally. A double-exposure technique using fluorescent drop photography was used to make size and velocity measurements at selected locations in a steady ethanol spray formed by a swirl atomizer. The size-velocity data were categorized to construct bivariate spray density functions to describe the spray immediately after formation and during downstream propagation. It was found that a statistical treatment of drop velocity was supported by the data. Spray density function shapes and modal characteristics depended strongly on position and the amount of droplet-gas interaction that had occurred. Bimodal density functions were formed by environmental interaction during downstream propagation. Large differences were also found between spatial mass density and mass flux size distributions at the same location.

  12. Convergent spray process for environmentally friendly coatings

    Science.gov (United States)

    Scarpa, Jack

    1995-01-01

    Conventional spray application processes have poor transfer efficiencies, resulting in an exorbitant loss in materials, solvents, and time. Also, with ever tightening Environmental Protection Agency (EPA) regulations and Occupational Safety and Health Administration requirements, the low transfer efficiencies have a significant impact on the quantities of materials and solvents that are released into the environment. High solids spray processes are also limited by material viscosities, thus requiring many passes over the surface to achieve a thickness in the 0.125 -inch range. This results in high application costs and a negative impact on the environment. Until recently, requirements for a 100 percent solid sprayable, environmentally friendly, lightweight thermal protection system that can be applied in a thick (greater than 0.125 inch) single-pass operation exceeded the capability of existing systems. Such coatings must be applied by hand lay-up techniques, especially for thermal and/or fire protection systems. The current formulation of these coatings has presented many problems such as worker safety, environmental hazards, waste, high cost, and application constraints. A system which can apply coatings without using hazardous materials would alleviate many of these problems. Potential applications include the aerospace thermal protective specialty coatings, chemical and petroleum industries that require fire-protection coatings that resist impact, chemicals, and weather. These markets can be penetrated by offering customized coatings applied by automated processes that are environmentally friendly.

  13. Investigation of spray characteristics from a low-pressure common rail injector for use in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Lee, Kihyung; Reitz, Rolf D.

    2004-03-01

    Homogeneous charge compression ignition (HCCI) combustion provides extremely low levels of pollutant emissions, and thus is an attractive alternative for future IC engines. In order to achieve a uniform mixture distribution within the engine cylinder, the characteristics of the fuel spray play an important role in the HCCI engine concept. It is well known that high-pressure common rail injection systems, mainly used in diesel engines, achieve poor mixture formation because of the possibility of direct fuel impingement on the combustion chamber surfaces. This paper describes spray characteristics of a low-pressure common rail injector which is intended for use in an HCCI engine. Optical diagnostics including laser diffraction and phase Doppler methods, and high-speed camera photography, were applied to measure the spray drop diameter and to investigate the spray development process. The drop sizing results of the laser diffraction method were compared with those of a phase Doppler particle analyser (PDPA) to validate the accuracy of the experiments. In addition, the effect of fuel properties on the spray characteristics was investigated using n-heptane, Stoddard solvent (gasoline surrogate) and diesel fuel because HCCI combustion is sensitive to the fuel composition. The results show that the injector forms a hollow-cone sheet spray rather than a liquid jet, and the atomization efficiency is high (small droplets are produced). The droplet SMD ranged from 15 to 30 µm. The spray break-up characteristics were found to depend on the fuel properties. The break-up time for n-heptane is shorter and the drop SMD is smaller than that of Stoddard solvent and diesel fuel.

  14. A Method to Predict the Thickness of Poorly-Bonded Material Along Spray and Spray-Layer Boundaries in Cold Spray Deposition

    Science.gov (United States)

    Li, Yangfan; Hamada, Yukitaka; Otobe, Katsunori; Ando, Teiichi

    2016-12-01

    Multi-traverse CS provides a unique means for the production of thick coatings and bulk materials from powders. However, the material along spray and spray-layer boundaries is often poorly bonded as it is laid by the leading and trailing peripheries of the spray that carry powder particles with insufficient kinetic energy. For the same reason, the splats in the very first layer deposited on the substrate may not be bonded well either. A mathematical spray model was developed based on an axisymmetric Gaussian mass flow rate distribution and a stepped deposition yield to predict the thickness of such poorly-bonded layers in multi-traverse CS deposition. The predicted thickness of poorly-bonded layers in a multi-traverse Cu coating falls in the range of experimental values. The model also predicts that the material that contains poorly bonded splats could exceed 20% of the total volume of the coating.

  15. A Method to Predict the Thickness of Poorly-Bonded Material Along Spray and Spray-Layer Boundaries in Cold Spray Deposition

    Science.gov (United States)

    Li, Yangfan; Hamada, Yukitaka; Otobe, Katsunori; Ando, Teiichi

    2017-02-01

    Multi-traverse CS provides a unique means for the production of thick coatings and bulk materials from powders. However, the material along spray and spray-layer boundaries is often poorly bonded as it is laid by the leading and trailing peripheries of the spray that carry powder particles with insufficient kinetic energy. For the same reason, the splats in the very first layer deposited on the substrate may not be bonded well either. A mathematical spray model was developed based on an axisymmetric Gaussian mass flow rate distribution and a stepped deposition yield to predict the thickness of such poorly-bonded layers in multi-traverse CS deposition. The predicted thickness of poorly-bonded layers in a multi-traverse Cu coating falls in the range of experimental values. The model also predicts that the material that contains poorly bonded splats could exceed 20% of the total volume of the coating.

  16. Current implications of past DDT indoor spraying in Oman.

    Science.gov (United States)

    Booij, Petra; Holoubek, Ivan; Klánová, Jana; Kohoutek, Jiří; Dvorská, Alice; Magulová, Katarína; Al-Zadjali, Said; Čupr, Pavel

    2016-04-15

    In Oman, DDT was sprayed indoors during an intensive malaria eradication program between 1976 and 1992. DDT can remain for years after spraying and is associated with potential health risk. This raises the concern for human exposure in areas where DDT was used for indoor spraying. Twelve houses in three regions with a different history of DDT indoor spraying were chosen for a sampling campaign in 2005 to determine p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and p,p'-dichlorodiphenyldichloroethane (p,p'-DDD) levels in indoor air, dust, and outdoor soil. Although DDT was only sprayed indoor, p,p'-DDT, p,p'-DDE and p,p'-DDD were also found in outdoor soil. The results indicate that release and exposure continue for years after cessation of spraying. The predicted cancer risk based on concentrations determined in 2005, indicate that there was still a significant cancer risk up to 13 to 16years after indoor DDT spraying. A novel approach, based on region-specific half-lives, was used to predict concentrations in 2015 and showed that more than 21years after spraying, cancer risk for exposure to indoor air, dust, and outdoor soil are acceptable in Oman for adults and young children. The model can be used for other locations and countries to predict prospective exposure of contaminants based on indoor experimental measurements and knowledge about the spraying time-schedule to extrapolate region-specific half-lives and predict effects on the human population years after spraying.

  17. A comparison between spray drying and spray freeze drying to produce an influenza subunit vaccine powder for inhalation

    NARCIS (Netherlands)

    Saluja, V.; Amorij, J-P.; Kapteyn, J. C.; de Boer, A. H.; Frijlink, H. W.; Hinrichs, W. L. J.

    2010-01-01

    The aim of this study was to investigate two different processes to produce a stable influenza subunit vaccine powder for pulmonary immunization i.e. spray drying (SD) and spray freeze drying (SFD). The formulations were analyzed by proteolytic assay, single radial immunodiffusion assay (SRID), casc

  18. Spray pattern and droplet size analyses for high-shear viscosity determination of aqueous suspension corticosteroid nasal sprays.

    Science.gov (United States)

    Pennington, Justin; Pandey, Preetanshu; Tat, Henry; Willson, Jennifer; Donovan, Brent

    2008-09-01

    Aqueous suspension corticosteroid nasal sprays exhibit the rheological property of shear thinning, meaning they exhibit a decrease in viscosity upon application of shear. Most rheological methods are limited in the amount of shear that can be applied to samples (approximately 1,000 s(-1)) and thus can only approximate the viscosities at the high-shear conditions of nasal spray devices (approximately 10(5)-10(6) s(-1)). In the current work, spray area and droplet size were shown to demonstrate viscosity dependence. Three Newtonian fluids were used to determine equations to approximate viscosity at the spray nozzle from correlations to spray area and droplet size using a standard 100 microL Pfeiffer nasal spray pump. Several shear-thinning solutions, including four commercial aqueous suspension corticosteroid nasal sprays and three aqueous Avicel (1, 2, and 3%, wt/wt) samples, were analyzed to demonstrate the ability of spray area and droplet size analysis to estimate high-shear viscosities. The calculated viscosity values trend in accordance with the rheometer data along with the ability to distinguish differences between all samples analyzed.

  19. A comparison between spray drying and spray freeze drying to produce an influenza subunit vaccine powder for inhalation

    NARCIS (Netherlands)

    Saluja, V.; Amorij, J-P.; Kapteyn, J. C.; de Boer, A. H.; Frijlink, H. W.; Hinrichs, W. L. J.

    2010-01-01

    The aim of this study was to investigate two different processes to produce a stable influenza subunit vaccine powder for pulmonary immunization i.e. spray drying (SD) and spray freeze drying (SFD). The formulations were analyzed by proteolytic assay, single radial immunodiffusion assay (SRID),

  20. Breakup characteristics of a liquid jet in subsonic crossflow

    Science.gov (United States)

    Gopala, Yogish

    This thesis describes an experimental investigation of the breakup processes involved in the formation of a spray created by a liquid jet injected into a gaseous crossflow. This work is motivated by the utilization of this method to inject fuel in combustors and afterburners of airplane engines. This study aims to develop a better understanding of the spray breakup processes and to provide better experimental inputs to improve the fidelity of numerical models. A review of the literature in this field identified the fundamental physical processes involved in the breakup of the spray and the dependence of spray properties on operating conditions. The time taken for the liquid column to break up into ligaments and droplets, the primary breakup time and the effect of injector geometry on the spray formation processes and spray properties as the key research areas in which research done so far has been inadequate. Determination of the location where the liquid column broke up was made difficult by the presence of a large number of droplets surrounding it. This study utilizes the liquid jet light guiding technique that enables accurate measurements of this location for a wide range of operating conditions. Prior to this study, the primary breakup time was thought to be a function the density ratio of the liquid and the gas, the diameter of the orifice and the air velocity. This study found that the time to breakup of the liquid column depends on the Reynolds number of the liquid jet. This suggests that the breakup of a turbulent liquid jet is influenced by both the aerodynamic breakup processes and the turbulent breakup processes. Observations of the phenomenon of the liquid jet splitting up into two or more jets were made at some operating conditions with the aid of the new visualization technique. Finally, this thesis investigates the effect of injector geometry on spray characteristics. One injector was a round edged orifice with a length to diameter ratio of 1 and a

  1. The Production of a Stable Infliximab Powder: The Evaluation of Spray and Freeze-Drying for Production

    Science.gov (United States)

    Kanojia, Gaurav; Have, Rimko ten; Bakker, Arjen; Wagner, Koen; Frijlink, Henderik W.; Kersten, Gideon F. A.; Amorij, Jean-Pierre

    2016-01-01

    In prospect of developing an oral dosage form of Infliximab, for treatment of Crohn’s disease and rheumatoid arthritis, freeze-drying (vial vs Lyoguard trays) and spray-drying were investigated as production method for stable powders. Dextran and inulin were used in combination with sucrose as stabilizing excipients. The drying processes did not affect Infliximab in these formulations, i.e. both the physical integrity and biological activity (TNF binding) were retained. Accelerated stability studies (1 month at 60°C) showed that the TNF binding ability of Infliximab was conserved in the freeze-dried formulations, whereas the liquid counterpart lost all TNF binding. After thermal treatment, the dried formulations showed some chemical modification of the IgG in the dextran-sucrose formulation, probably due to Maillard reaction products. This study indicates that, with the appropriate formulation, both spray-drying and freeze-drying may be useful for (bulk) powder production of Infliximab. PMID:27706175

  2. Design of self-dispersible dry nanosuspension through wet milling and spray freeze-drying for poorly water-soluble drugs.

    Science.gov (United States)

    Niwa, Toshiyuki; Danjo, Kazumi

    2013-11-20

    The purpose of the present research is to establish a novel nanosizing technique starting from wet nano-milling, named "dry nanosuspension" technique for poorly water-soluble drugs. The spray freeze-drying (SFD) method was applied instead of the spray-drying one previously developed. Drug particles were milled in the aqueous solution of dispersing agents using an oscillating beads-milling apparatus. The milled nanosuspension was sprayed to the surface of liquid nitrogen, and the resultant iced droplets were freeze-dried to obtain the powdery product. The loading ratio of a dispersing agent was investigated to enhance its redispersing property. Dry nanosuspension, which could be spontaneously dispersed into original nanosuspension in water, was obtained by SFD process. It was assumed that self dispersion property would be attributed to its structure with porous network, in which the primary milled drug crystals were embedded. Such unique structure contributed greatly to immediate release behaviors of the drug in gastrointestinal buffered media. These pharmaceutical properties were enhanced by increasing the ratio of the dispersing agent to the drug and the solid content in suspension to be sprayed. The present technique via wet milling and spray freeze-drying processes would be a novel dissolution-enhanced technology for poorly water-soluble drugs.

  3. Study of the Porosity in Plasma-Sprayed Alumina through an Innovative Three-Dimensional Simulation of the Coating Buildup

    Science.gov (United States)

    Beauvais, S.; Guipont, V.; Jeandin, M.; Jeulin, D.; Robisson, A.; Saenger, R.

    2008-11-01

    Porosity is a key feature of a thermally sprayed coating microstructure. Within ceramic coatings, porosity is made of pores and cracks of various shapes, dimensions, and orientations. Cracks can be intralamellar or interlamellar due to the buildup of the coating, which leads to piled-up lamellae from impinging and the additional rapid solidification of liquid droplets. Pores are interconnected with cracks, which results in a three-dimensional (3-D) porosity network. Direct observation of this network is an intricate task and current attempts remain somewhat limited. A 3-D simulation of this network was, therefore, developed in this work, based on a stochastic approach to the building up of simulated lamellae in the sprayed microstructure. A library of mathematical objects was achieved from morphological measurements, using confocal microscopy of actual isolated flattened lamellae, i.e., “splats” and scanning electron microscopy (SEM). This stochastic approach to the simulation of hundreds of lamellae also involves the random distribution of cracks and pores. Simulation fit parameters were selected according to the overall characteristics of porosity ( i.e., content, orientation, size, etc.) that were determined from the thorough quantitative image analysis (QIA) of cross-sectioned plasma-sprayed alumina coatings. Two plasma modes that varied the atmosphere in a controlled-atmosphere plasma spraying (CAPS) chamber were applied, to produce the microstructures of two different alumina coatings. The 3-D random modeling tool allowed the processing of a volume of digital material through a 3-D simulated binary image of a two-phased composite material. Using one 3-D image result of the simulation, finite element (FE) calculations were performed, in order to study the overall dielectric properties of a plasma-sprayed alumina as a function of porosity. The influence of anisotropy is discussed, in particular, and both analytical and numerical predicted values were

  4. Comparison between two-phase and one-phase SLIPI for instantaneous imaging of transient sprays

    Science.gov (United States)

    Mishra, Yogeshwar Nath; Kristensson, Elias; Koegl, Matthias; Jönsson, Joakim; Zigan, Lars; Berrocal, Edouard

    2017-09-01

    Imaging through optically dense sprays is challenging due to the detection of multiple light scattering, which blurs the recorded images and limits visibility. Structured laser illumination planar imaging (SLIPI) is a technique that is capable of reducing the intensity contribution that stems from multiple scattering in a light sheet imaging configuration. The conventional SLIPI approach is based on recording three modulated sub-images successively, each having a different spatial phase, and has, therefore, been mostly used for temporally averaged imaging. To circumvent this limitation and image spray dynamics, `instantaneous' two-phase (2p) and single-phase (1p) SLIPI approaches have recently been developed. The purpose of the work presented here is to compare these two approaches in terms of optical design, image post-processing routines, multiple scattering suppression ability, and spatial resolution. The two approaches are used to image a transient direct-injection spark-ignition ethanol spray, for both liquid laser-induced fluorescence and Mie scattering detection. The capabilities of the approaches for multiple scattering suppression and image formation have also been numerically modeled by means of Monte Carlo simulation. This article shows that both approaches efficiently suppress the contribution from multiple light scattering, providing images with an intensity profile close to the corresponding single scattering case. Experimentally, this suppression renders both an improvement in image contrast and the removal of undesired stray light components that could be interpreted as signal. However, while 2p-SLIPI preserves most of the initial spatial resolution, 1p-SLIPI results in a loss of spatial resolution, where high-frequency image information is not visible anymore. Thus, there is a trade-off between preserving the most detailed information of the spray structure—with 2p-SLIPI—and being able to record an SLIPI image from a single modulated image

  5. Phytochemical Characterizationand in vivo Anti-inflammatory and Wound-healing Activities of Argania spinosa (L. Skeels Seed Oil

    Directory of Open Access Journals (Sweden)

    Hadjira Dakiche

    2017-03-01

    Full Text Available The extracted oil of Argania spinosa (L. was investigated in regard to its fatty acid composition and polyphenols by Gas Chromatography-Mass Spectrometry (GC–MS and Ultra-high Performance Liquid Chromatography-Electro Spray Ionization-Quadruple Time Of Flight-Mass Spectrometry (UPLC-ESI-QTOF-MS, respectively. The reduction rate of topical inflammation of extracted oil was calculated using a mouse model. The skin toxicity of argan oil on intact and damaged skin was assessed using a rabbit model. The findings revealed a rich content of monounsaturated and polyunsaturated fatty acids and presence of phenolic acids. The oil exhibited a reduction of inflammation and facilitated a healing process without any irritation. The experimental study revealed that A. spinosa seed oil displays remarkable wound-healing and anti-inflammatory activities related to its chemical composition. Argan oil has positive potential for skin medicinal application.

  6. Effect of Injector Geometry on Atomization of a Liquid-Liquid Double Swirl Coaxial Injector Using Non-invasive Laser, Optical and X-ray Techniques

    Science.gov (United States)

    Radke, C. R.; Meyer, T. R.

    2014-01-01

    The spray characteristics of a liquid-liquid double swirl coaxial injector were studied using non-invasive optical, laser, and X-ray diagnostics. A parametric study of injector exit geometry demonstrated that spray breakup time, breakup type and sheet stability could be controlled with exit geometry. Phase Doppler interferometry was used to characterize droplet statistics and non-dimensional droplet parameters over a range of inlet conditions and for various fluids allowing for a study on the role of specific fluid properties in atomization. Further, X-ray radiography allowed for investigation of sheet thickness and breakup length to be quantified for different recess exit diameters and inlet pressures. Finally, computed tomography scans revealed that the spray cone was distinctively non-uniform and comprised of several pockets of increased mass flux.

  7. Influence of handpiece maintenance sprays on resin bonding to dentin

    Directory of Open Access Journals (Sweden)

    Toyotarou Sugawara

    2010-03-01

    Full Text Available Toyotarou Sugawara1, Atsushi Kameyama2, Akiko Haruyama3, Takumi Oishi4, Nobuyuki Kukidome2, Yasuaki Takase2, Masatake Tsunoda21Undergraduate Student, Tokyo Dental College, Chiba, Japan; 2Division of General Dentistry, Tokyo Dental College Chiba Hospital, Chiba, Japan; 3Department of Dental Materials Science, Tokyo Dental College, Chiba, Japan; 4Department of Dentistry and Oral Surgery, Keio University School of Medicine, Tokyo, JapanObjective: To investigate the influence of maintenance spray on resin bonding to dentin.Materials and methods: The crown of extracted, caries-free human molars was transversally sectioned with a model trimmer to prepare the dentin surfaces from mid-coronal sound dentin, and then uniformly abraded with #600 silicon carbide paper. The dentin surfaces were randomly divided into three groups: oil-free spray group where maintenance cleaner for air bearing handpieces was sprayed onto the dentin surface for 1 s and rinsed with water spray for 30 s; oil-containing spray group where maintenance cleaner for micro motor handpieces was sprayed onto the dentin surface for 1 s and rinsed with water spray for 30 s; and control group where the surface was rinsed with water spray for 30 s and then air-dried. These surfaces were then bonded with Clearfil SE Bond (Kuraray Medical, and resin composite (Clearfil AP-X, Kuraray Medical build-up crowns were incrementally constructed on the bonded surfaces. After storage for 24 h in 37°C water, the bonded teeth were sectioned into hour-glass shaped slices (0.7-mm thick perpendicular to the bonded surfaces. The specimens were then subjected to microtensile bond strength (μTBS testing at a crosshead speed of 1.0 mm/min. Data were analyzed with one-way ANOVA and the Tukey-Kramer test.Results: Maintenance spray-contaminated specimens (oil-free and oil-containing spray groups showed significantly lower μTBS than control specimens (P < 0.05. However, there was no significant difference between

  8. Subsidizing Liquidity

    DEFF Research Database (Denmark)

    Malinova, Katya; Park, Andreas

    2015-01-01

    Facing increased competition over the last decade, many stock exchanges changed their trading fees to maker-taker pricing, an incentive scheme that rewards liquidity suppliers and charges liquidity demanders. Using a change in trading fees on the Toronto Stock Exchange, we study whether and why...

  9. Generación de Spray por Vibración de un Fluido Viscoelastico Spray Generation by Vibration of a Viscoelastic Fluid

    Directory of Open Access Journals (Sweden)

    Gabriel Ferreyra

    2009-01-01

    Full Text Available En este trabajo se estudia la emisión de spray de liquidos viscoelasticos generada mediante vibración, asi como la influencia de sus propiedades físicas en el tamaño de las gotas. El recipiente conteniendo el fluido es sometido a un campo de fuerzas vertical periódico, del cual se controlan la amplitud de la excitación y la frecuencia del mismo. Se utilizaron diferentes mezclas de queroseno con agregado de polímero viscoelástico, resultando validos los modelos aplicados a fluidos Newtonianos dentro de las condiciones de trabajo. Tambien se obtuvo la dependencia del tamaño de gota con la cantidad de polimero agregado, la aceleracion y la frecuencia aplicadas. Se concluye que los modelos desarrollados para fluidos Newtonianos pueden ser aplicados a liquidos de características similares a los utilizados en estas experiencias.In this paper, viscoelastic liquids spray emission generated by vibration and the influence of their physical properties are studied. The fluid contained in a cell is subjected to a field of periodic vertical forces, for which the excitation amplitude and frequency are controlled. Different mixtures of kerosene with viscoelastic polymer were used and results were modelled using equations applicable to Newtonian fluids with acceptable results within the values of the operating conditions considered. Also, the dependence of drop size with the quantity of polymer added, the acceleration and the frequency applied was determined. It is concluded that Newtonian fluids models can be applied to liquids with characteristics similar to those studied in this work.

  10. Liquid pearls

    CERN Document Server

    Bremond, Nicolas; Bibette, Jérôme

    2010-01-01

    This fluid dynamics video reports how to form liquid core capsules having a thin hydrogel elastic membrane named liquid pearls. These fish-egg like structures are initially made of a millimetric liquid drop, aqueous or not, coated with an aqueous liquid film containing sodium alginate that gels once the double drop enters a calcium chloride bath. The creation of such pearls with micrometer thick membrane requires to suppress mixing until gelling takes place. Here, we show that superimposing a two dimensional surfactant precipitation at the interface confers a transient rigidity that can damp the shear induced instability at impact. Based on this, pearls containing almost any type of liquids can be created. The video focuses on the dynamics of the entry of the compound drop into the gelling bath.

  11. Autonomous Precision Spraying Trials Using a Novel Cell Spray Implement Mounted on an Armadillo Tool Carrier

    DEFF Research Database (Denmark)

    Jensen, Kjeld; Stigaard Laursen, Morten; Midtiby, Henrik

    Precision weeding is one of the most promising applications for autonomous service robots in biological production. Herbicides have been the default weeding solution during the past decades, but there is a growing concern about the environmental impact on drinking water reservoirs etc. The use...... with an Armadillo robotic tool carrier consisting of two battery powered track modules mounted on each side of the implement. This paper focus on the cell sprayer implement design including camera system, sprayer module and integration with the service robot and the robot software. The FroboMind software platform...... of computer vision and precision spraying technology makes it possible to significantly reduce the consumption of herbicides. The work presented here is part of a project with the purpose of performing autonomous precision spraying trials. In this work a novel cell sprayer designed for large scale tests...

  12. Granule size control and targeting in pulsed spray fluid bed granulation.

    Science.gov (United States)

    Ehlers, Henrik; Liu, Anchang; Räikkönen, Heikki; Hatara, Juha; Antikainen, Osmo; Airaksinen, Sari; Heinämäki, Jyrki; Lou, Honxiang; Yliruusi, Jouko

    2009-07-30

    The primary aim of the study was to investigate the effects of pulsed liquid feed on granule size. The secondary aim was to increase knowledge of this technique in granule size targeting. Pulsed liquid feed refers to the pump changing between on- and off-positions in sequences, called duty cycles. One duty cycle consists of one on- and off-period. The study was performed with a laboratory-scale top-spray fluid bed granulator with duty cycle length and atomization pressure as studied variables. The liquid feed rate, amount and inlet air temperature were constant. The granules were small, indicating that the powder has only undergone ordered mixing, nucleation and early growth. The effect of atomizing pressure on granule size depends on inlet air relative humidity, with premature binder evaporation as a reason. The duty cycle length was of critical importance to the end product attributes, by defining the extent of intermittent drying and rewetting. By varying only the duty cycle length, it was possible to control granule nucleation and growth, with a wider granule size target range in increased relative humidity. The present study confirms that pulsed liquid feed in fluid bed granulation is a useful tool in end product particle size targeting.

  13. Spray deposition for making large size billet with swing atomizer

    Institute of Scientific and Technical Information of China (English)

    LI Jian-ping; LIU Tao; TANG Qing-yun; HAN Lei; ZHONG Jue

    2008-01-01

    The movement mode of the atomizer is a very important parameter during spray deposition process, which has direct influence on the size and surface texture of the billets. To resolve the problem of manufacturing large size billets, a method of spray deposition by the atomizer with off-center swing was put forward. The atomizer was driven by the alternating current servomotor to swing within 7° at varying speed. The influence of the atomizer parameters, such as translation of the atomizer, swing angle of the atomizer, substrate falling speed and spraying pressure, on the spray deposition was studied. The optimized parameters of the spray deposition process were obtained. The results show that the large size billets with uniform surface quality can be made through adjusting swing frequency and angle of the atomizer, offset distance of the atomizer and inclined angle of the substrate; the valid spray area will decrease and the dimension of top surface will reduce when pressure is less than 0.4 MPa within certain spray distance; meantime, the moving time and cooling time of the droplets are extended, which will lead to loose structure and bad densification. When the pressure, the swing angle and the eccentric offset of the atomization equal 0.5MPa, 7° and 60mm,respectively, large size billets with fine texture and diameter of 500mm can be produced.

  14. Modeling and Experiments of Spray System for Cable Painting Robot

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jia-liang; Lü Tian-sheng; LI Bei-zhi

    2008-01-01

    Many cable-stayed bridges have been built in the world in the past decades,and cable-stayed structures have been adopted in many large constructions.The cable painting robot is safe and economically efficient for stay cable maintenance.In order to satisfy the need for spraying cables in hiigh attitude,an automatic cable spray system for cable painting robots is presented in this paper.Using the βdistribution,paint thickness distribution on a cylinder surface is modeled.The spray gun's number,angle and movement are analyzed to get coat evenness.Then a robotic spray system engineering prototype has been developed,which includes a cable electric running climbing base,a spray cover,four airless spray guns and a pressurized paint container.Experiments indicate that four airless spray guns can guarantee good coat quality for general stay cables.The field tests have been successfully conducted on Nanpu Bridge,Shanghai.

  15. Development of precision spray forming for rapid tooling

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yunfeng [VTT Technical Research Centre of Finland, POB 1000, FI-02044 VTT (Finland); Hannula, Simo-Pekka [VTT Technical Research Centre of Finland, POB 1000, FI-02044 VTT (Finland); Laboratory of Materials Science, Helsinki University of Technology, POB 6200, FI-02015 TKK (Finland)], E-mail: simo-pekka.hannula@tkk.fi

    2008-03-25

    The aim of the work is to improve the capability of the precision spray forming (PSF) rapid tooling process so that it can be extended to various applications. This work comprises the upgrading of the current spray-forming machine from single atomizer to twin atomizers, so that the capability is much improved in terms of insert size and complexity. As a result, the insert size is increased from about 200 mm to 400 mm in diameter, and the process is more reliable to make complex structures. Know-how is accumulated for making large and/or complex inserts with controllable surface and internal soundness. A process of spray forming conformal cooling channels in die inserts or other components used at elevated temperatures is also developed and various mould inserts are spray formed. In this paper the plant modification is described. It is shown that the twin atomizers are more reliable in spray forming small inserts of about 200 mm in diameter and of high complexity than the single atomizer system. Spray forming of disc type inserts up to 400 mm diameter is demonstrated. Influence of deposition temperature and substrate moving speed, as well as the treatment of the ceramic mould surface is determined and the technical measures to prevent surface defects related to large insert spray forming are specified.

  16. Characteristics of spray pattern on injection conditions using GDI injector

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T.H. [Hanyang University, Graduate School, Seoul (Korea); Lee, K.H.; Lee, C.S. [Hanyang University, Seoul (Korea); Kim, J.Y.; Baik, S.K. [Kefico (Korea)

    1999-11-01

    Recently GDI(Gasoline Direct Injection) engine is spotlighted to achieve higher thermal efficiency under partial loads and better performance at full loads. To realize these, it is essential to make both super-lean stratified combustion and homogeneous combustion. When compared to PFI(Port Fuel Injection) engine, GDI engine needs more complicated control and optimal design with piston cavity. In addition, spray pattern must be optimized according to injection timing because ambient pressure in combustion chamber is also varied. Thus spray structure should be analyzed in details to meet various conditions. In this experimental study, system of spray visualization was built for coping with variable ambient pressures in high pressure chamber and the spray characteristics were investigated for a few sample GDI injectors. To make clear spray pattern, the images for vertical and horizontal sections were taken as fuel injection was processed. With an increase at the ambient pressure in chamber, the tip penetration and spray diameter is inclined to decrease due to rising resistance caused by the drag force of the ambient air. These results provide the information on macro spray structure and design factors for developing GDI injector. (author). 4 refs., 12 figs., 1 tab.

  17. Process optimization of ultrasonic spray coating of polymer films.

    Science.gov (United States)

    Bose, Sanjukta; Keller, Stephan S; Alstrøm, Tommy S; Boisen, Anja; Almdal, Kristoffer

    2013-06-11

    In this work we have performed a detailed study of the influence of various parameters on spray coating of polymer films. Our aim is to produce polymer films of uniform thickness (500 nm to 1 μm) and low roughness compared to the film thickness. The coatings are characterized with respect to thickness, roughness (profilometer), and morphology (optical microscopy). Polyvinylpyrrolidone (PVP) is used to do a full factorial design of experiments with selected process parameters such as temperature, distance between spray nozzle and substrate, and speed of the spray nozzle. A mathematical model is developed for statistical analysis which identifies the distance between nozzle and substrate as the most significant parameter. Depending on the drying of the sprayed droplets on the substrate, we define two broad regimes, "dry" and "wet". The optimum condition of spraying lies in a narrow window between these two regimes, where we obtain a film of desired quality. Both with increasing nozzle-substrate distance and temperature, the deposition moves from a wet state to a dry regime. Similar results are also achieved for solvents with low boiling points. Finally, we study film formation during spray coating with poly (D,L-lactide) (PDLLA). The results confirm the processing knowledge obtained with PVP and indicate that the observed trends are identical for spraying of other polymer films.

  18. Controlling malaria with indoor residual spraying in spatially heterogenous environments.

    Science.gov (United States)

    Al-Arydah, Mo'tassem; Smith, Robert

    2011-10-01

    Indoor residual spraying-spraying insecticide inside houses to kill mosquitoes-has been one of the most effective methods of disease control ever devised, being responsible for the near-eradication of malaria from the world in the third quarter of the twentieth century and saving tens of millions of lives. However, with malaria resurgence currently underway, it has received relatively little attention, been applied only in select physical locations and not always at regular intervals. We extend a time-dependent model of malaria spraying to include spatial heterogeneity and address the following research questions: 1. What are the effects of spraying in different geographical areas? 2. How do the results depend upon the regularity of spraying? 3. Can we alter our control strategies to account for asymmetric phenomena such as wind? We use impulsive partial differential equation models to derive thresholds for malaria control when spraying occurs uniformly, within an interior disc or under asymmetric advection effects. Spatial heterogeneity results in an increase in the necessary frequency of spraying, but control is still achievable.

  19. Effect of the Shape Factor on the Cold-Spraying Dynamic Characteristics of Sprayed Particles

    Science.gov (United States)

    Song, Jun; Liu, Juanfang; Chen, Qinghua; Li, Kepin

    2017-09-01

    Silicon powder was chosen to be deposited by cold spraying for the consideration of possible applications in lithium ion batteries. The influence of the silicon particle shapes other than spherical on the impact velocity and temperature for different working parameters of the gas streams have been numerically investigated by using computational fluid dynamics modeling. The results show that, for same equivalent diameter, the particle impact velocities increase to a maximum velocity when the shape factor increases to a certain value and then decreases to the impact velocity of spherical particles. In the cold-spraying process, the particle velocity profile for smaller shape factors is much closer to that of the gas stream due to the larger particle surface area. Furthermore, the particle impact velocity increment for smaller shape factors is much more remarkable with a higher main propulsion gas temperature and higher carrier gas pressure. The effect of raising the main propulsion gas pressure on the impact velocity of the particles with very smaller shape factors is negligible. The particle impact velocity and temperature can be altered by not only the change of the working parameters of the gas steams but also the change of the sizes and shapes of the sprayed particles.

  20. Functional Analysis and Treatment of Rumination Using Fixed-Time Delivery of a Flavor Spray

    Science.gov (United States)

    Wilder, David A.; Register, Martisa; Register, Stanley; Bajagic, Vedrana; Neidert, Pamela L.

    2009-01-01

    A functional analysis suggested that rumination exhibited by an adult with autism was maintained by automatic reinforcement. Next, a preference assessment with three flavor sprays (i.e., flavored sprays used by dieters) showed that apple pie spray was most preferred. Finally, the effects of fixed-time delivery of the apple pie spray on levels of…