WorldWideScience

Sample records for centrifugal separators

  1. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  2. Gas centrifugal separator

    International Nuclear Information System (INIS)

    Object: To enhance separating performance by jointly using separating action of impulse wave without increasing peripheral speed of a gas centrifugal separator and lengthening a cylindrical portion thereof. Structure: A mixed gas is introduced into a rotating cylinder from a mixed gas pipe and is separated into gas rich in light component and gas decreased in light component, these gases being taken outside the rotating cylinder through a product opening and a fixed waste pipe, respectively. A fixed product recycling pipe is disposed between an upper end plate and an upper buffer plate of the rotating cylinder the recycling pipe having an opening formed at the leading end so as to oppose to the rotating mixed gas, and the gas introduced from the opening is re-introduced into the central portion of the rotating cylinder for recirculation. A waste pipe is disposed between a lower end plate and a lower buffer plate of the rotating cylinder, and the gas not introduced into the opening of the waste pipe is circulated within the rotating cylinder. (Kamimura, M.)

  3. Continuous-Flow Centrifugal Separator

    Science.gov (United States)

    Waldron, Robert D.

    1988-01-01

    Apparatus combines principles of centrifugal and cyclone separators to control movement of solid or liquid particles suspended in flowing gas. Spinning disk contains radial channels, width varys as function of distance from center. Gas flows from outer ring around disk toward center. Particles in gas collected at periphery, center or both.

  4. Centrifugal separator devices, systems and related methods

    Science.gov (United States)

    Meikrantz, David H.; Law, Jack D.; Garn, Troy G.; Todd, Terry A.; Macaluso, Lawrence L.

    2012-03-20

    Centrifugal separator devices, systems and related methods are described. More particularly, fluid transfer connections for a centrifugal separator system having support assemblies with a movable member coupled to a connection tube and coupled to a fixed member, such that the movable member is constrained to movement along a fixed path relative to the fixed member are described. Also, centrifugal separator systems including such fluid transfer connections are described. Additionally, methods of installing, removing and/or replacing centrifugal separators from centrifugal separator systems are described.

  5. Centrifugal separators and related devices and methods

    Science.gov (United States)

    Meikrantz, David H.; Law, Jack D.; Garn, Troy G.; Macaluso, Lawrence L.; Todd, Terry A.

    2012-03-06

    Centrifugal separators and related methods and devices are described. More particularly, centrifugal separators comprising a first fluid supply fitting configured to deliver fluid into a longitudinal fluid passage of a rotor shaft and a second fluid supply fitting sized and configured to sealingly couple with the first fluid supply fitting are described. Also, centrifugal separator systems comprising a manifold having a drain fitting and a cleaning fluid supply fitting are described, wherein the manifold is coupled to a movable member of a support assembly. Additionally, methods of cleaning centrifugal separators are described.

  6. Separation of uranium isotopes by gas centrifugation

    International Nuclear Information System (INIS)

    The uranium isotope enrichment is studied by means of the countercurrent gas centrifuge driven by thermal convection. A description is given of (a) the transfer and purification of the uranium hexafluoride used as process gas in the present investigation; (b) the countercurrent centrifuge ZG3; (c) the system designed for the introduction and extraction of the process gas from the centrifuge; (d) the measurement of the process gas flow rate through the centrifuge; (e) the determination of the uranium isotopic abundance by mass spectrometry; (f) the operation and mechanical behavior of the centrifuge and (g) the isotope separation experiments, performed, respectively, at total reflux and with production of enriched material. The results from the separation experiments at total reflux are discussed in terms of the enrichment factor variation with the magnitude and flow profile of the countercurrent given by the temperature difference between the rotor covers. As far as the separation experiments with production are concerned, the discussion of their results is presented through the variation of the enrichment factor as a function of the flow rate, the observed asymmetry of the process and the calculated separative power of the centrifuge. (Author)

  7. Separative power of an optimised concurrent gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Bogovalov, Sergey; Boman, Vladimir [National Research Nuclear University (MEPHI), Moscow (Russian Federation)

    2016-06-15

    The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s)2(300 K/T)(L/1 m) kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  8. Separative power of an optimised concurrent gas centrifuge

    CERN Document Server

    Bogovalov, S V

    2015-01-01

    The problem of separation of uranium isotopes in a concurrent gas centrifuge is solved analytically. Separative power of the optimized concurrent gas centrifuges equals to $\\delta U=12.7(V/700~{\\rm m/s})^2 (300 ~{\\rm K}/T)L, ~{\\rm kg ~SWU/yr}$, where $L$ and $V$ are the length and linear velocity of the rotor of the gas centrifuge, $T$ is the temperature. This formula well agrees with an empirical separative power of counter current gas centrifuges. The optimal value of the separative power is not unique on the plane $(p_w,v_z)$, where $p_w$ is pressure at the wall of the rotor and $v_z$ is axial velocity of the gas. This value is constant on a line defined by the equation $p_wv_z=constant$. Equations defining the mass flux and the electric power necessary to support the rotation of the gas centrifuge are obtained.

  9. Separation of Nanoparticles in Aqueous Multiphase Systems through Centrifugation

    KAUST Repository

    Akbulut, Ozge

    2012-08-08

    This paper demonstrates the use of aqueous multiphase systems (MuPSs) as media for rate-zonal centrifugation to separate nanoparticles of different shapes and sizes. The properties of MuPSs do not change with time or during centrifugation; this stability facilitates sample collection after separation. A three-phase system demonstrates the separation of the reaction products (nanorods, nanospheres, and large particles) of a synthesis of gold nanorods, and enriches the nanorods from 48 to 99% in less than ten minutes using a benchtop centrifuge. © 2012 American Chemical Society.

  10. Centrifugal Liquid/Gas Separator With Phase Detectors

    Science.gov (United States)

    Schneider, Steven J.

    1994-01-01

    Centrifugal liquid/gas separator that includes phase (liquid or gas) detectors helps ensure exclusiveness of each phase at its assigned outlet. Acoustic sensors in centrifugal liquid/gas separator measure speeds of sound in nominally pure liquid and nominally pure gas at liquid and gas outlets respectively. When speed of sound is that of pure liquid or gas, valve opens to let liquid or gas flow out.

  11. Over all separation factors for stable isotopes by gas centrifuge

    International Nuclear Information System (INIS)

    The separation factor for the elements with molar wight differences, γ0, is an important characteristic parameter for separation of varied isotopes. Besides the dependence on construction parameters of the gas centrifuge it depends on many variables. Some of them are operation conditions, such as feeding flow rate F, pressure at wall pw, temperature T0 and distribution temperature on the wall and others. Separation factor γ0 depends on physical properties, such as molar weight M, viscosity μ, product of ρD, where ρ is density of working media and D is its diffusion coefficient. It was taken four examples: UF6, WF6, OsO4 and Xe

  12. Effect of inner structure of centrifugal separator on particle classification performance

    OpenAIRE

    Yamamoto, Tetsuya; Watanabe, Natsuko; Fukui, Kunihiro; Yoshida, Hideto

    2009-01-01

    This study investigated the effects of the inner structure of a centrifugal separator on particle classification performance. The typical inner structure of centrifugal separators is as follows: a blade, which consists of two orthogonal plates. is inserted into the centrifugal separator to create rigid fluid and particle rotations. The results of the present study demonstrate that centrifugal separator performance was significantly improved by attachment of a cylinder to the center of a conve...

  13. Centrifugal steam-water separator for steam generators

    International Nuclear Information System (INIS)

    This invention concerns a centrifugal steam-water separator for steam generators, using natural circulation. The turbulence chamber includes a perforated venturi composed of a decreasing cone-shaped convergent duct and a cone-shaped divergent diffuser section increasing from the narrowest part to the turbulence chamber outlet. In this way, the jected liquid phase and any particles of solids it may contain can be discharged through the perforations into the annular space formed between the perforated venturi and the vessel to accumulate at the bottom of this annular space for subsequent removal. The advantages of the invention are that the diffuser of the perforated venturi is used as an additional separation path and with the recovery of pressure in mind, and that the water droplets ejected, as well as any particles contained in these droplets discharged or ejected outside the action area of the rotational flow into the annular space, can flow in a practically free way towards the bottom of the interior edge of the containment wall. Because of this, the pressure drop is reduced and the degree of separation improved. The steam-water separator of the invention is therefore particularly suitable for the high power steam generators of nuclear reactor facilities. For a given steam output, it is possible with the lay-out specified in this invention to reduce the required number of separation units

  14. Fast centrifugal partition chromatography as a preparative-scale separation technique for citrus flavones

    Science.gov (United States)

    Fast centrifugal partition chromatography (FCPC) is a preparative-scale separations methodology based on the principles of counter current chromatography. Separations by FCPC are typically achieved with higher recoveries and with lower solvent use compared to conventional column chromatography. HSCP...

  15. A fuzzy controlled three-phase centrifuge for waste separation

    International Nuclear Information System (INIS)

    The three-phase centrifuge technology discussed in this paper was developed by Neal Miller, president of Centech, Inc. The three-phase centrifuge is an excellent device for cleaning up oil field and refinery wastes which are typically composed of hydrocarbons, water, and solids. The technology is unique. It turns the waste into salable oil, reusable water, and landfill-able solids. No secondary waste is produced. The problem is that only the inventor can set up and run the equipment well enough to provide an optimal cleanup. Demand for this device has far exceeded a one man operation. There is now a need for several centrifuges to be operated at different locations at the same time. This has produced a demand for an intelligent control system, one that could replace a highly skilled operator, or at least supplement the skills of a less experienced operator. The control problem is ideally suited to fuzzy logic, since the centrifuge is a highly complicated machine operated entirely by the skill and experience of the operator. A fuzzy control system was designed for and used with the centrifuge

  16. Faults Analysis and Diagnosis of DR J-460 Dish Centrifugal Separator's Helical Gear

    Institute of Scientific and Technical Information of China (English)

    MA Xiao-jian; GAN Xue-hui

    2004-01-01

    The main faults of dish centrifugal separator's helical gear are described in this paper. In order to diagnose the DR J-460 dish centrifugal separator correctly, the vibration is tested with a helical gear under both normal and abnormal conditions. After comparing several general methods of the gear's fault feature extraction, a new convenient and effective method is presented on the basis of analyzing the vibration spectrum under different rotary velocities.

  17. Polymethylmethacrylate/Polyacrylonitrile Membranes via Centrifugal Spinning as Separator in Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Meltem Yanilmaz

    2015-04-01

    Full Text Available Electrospun nanofiber membranes have been extensively studied as separators in Li-ion batteries due to their large porosity, unique pore structure, and high electrolyte uptake. However, the electrospinning process has some serious drawbacks, such as low spinning rate and high production cost. The centrifugal spinning technique can be used as a fast, cost-effective and safe technique to fabricate high-performance fiber-based separators. In this work, polymethylmethacrylate (PMMA/polyacrylonitrile (PAN membranes with different blend ratios were produced via centrifugal spinning and characterized by using different electrochemical techniques for use as separators in Li-ion batteries. Compared with commercial microporous polyolefin membrane, centrifugally-spun PMMA/PAN membranes had larger ionic conductivity, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. Centrifugally-spun PMMA/PAN membrane separators were assembled into Li/LiFePO4 cells and these cells delivered high capacities and exhibited good cycling performance at room temperature. In addition, cells using centrifugally-spun PMMA/PAN membrane separators showed superior C-rate performance compared to those using microporous polypropylene (PP membranes. It is, therefore, demonstrated that centrifugally-spun PMMA/PAN membranes are promising separator candidate for high-performance Li-ion batteries.

  18. Numerical investigation on influence of feed condition on separation performance of gas centrifuge

    International Nuclear Information System (INIS)

    To investigate the influence of feed condition on the flow field and separation performance of gas centrifuge, flow field distribution was obtained by numerically solving linearized Navier-Stokes equation with finite difference method, which separation power was calculated based on. Curves of separative power changing with different feed parameters were drawn. The numerical results show that flow field distribution and separative performance have significant difference under different feed conditions. By comparing a large number of calculation results, combined with centrifugal separation theory, analyses were made about the mechanism that different feed factors influence separation performance of the centrifuge. A conclusion was obtained that position, axial velocity disturbance and angular velocity disturbance are main factors that influence flow field. The optimal position and feed angle are existed for the given model according the results. The research shows that the feed flow and mechanism of feed drive need further research (authors)

  19. Centrifugal separation and equilibration dynamics in an electron-antiproton plasma

    CERN Document Server

    Andresen, G B; Baquero-Ruiz, Marcelo; Bertsche, William; Bowe, Paul D; Butler, Eoin; Cesar, Claudio L; Chapman, Steven; Charlton, Michael; Deller, A; Eriksson, S; Fajans, Joel; Friesen, Tim; Fujiwara, Makoto C; Gill, David R; Gutierrez, A; Hangst, Jeffrey S; Hardy, Walter N; Hayden, Michael E; Humphries, Andrew J; Hydomako, Richard; Jonsell, Svante; Madsen, Niels; Menary, Scott; Nolan, Paul; Olin, Art; Povilus, Alexander; Pusa, Petteri; Robicheaux, Francis; Sarid, Eli; Silveira, Daniel M; So, Chukman; Storey, James W; Thompson, Robert I; van der Werf, Dirk P; Wurtele, Jonathan S; Yamazaki, Yasunori

    2011-01-01

    Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally-separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally-separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.

  20. Calculation of the separate parameters of a countercurrent centrifuge with an axially varying internal flow

    International Nuclear Information System (INIS)

    A review of the isotope separation theory for the countercurrent gas centrifuge is presented. The diffusion-convection equation is solved according to the ONSAGER-COHEN solution for the constant internal flow and adapted to an axially varying countercurrent flow. Based on that theory, a numerical program is developed for the calculation of the isotopic compositions and the separative parameters of the centrifuge. The influence of the feed flow and the internal parameters. Like cut and countercurrent flow, on the separative parameters is then analysed for a model-centrifuge, which afterwards is optimized with respect to its separative power. Finally, a comparison between the present calculation procedure and some published results, provided by different theories, shows deviations lower then 20%. (author)

  1. Dynamic considerations in the development of centrifugal separators used for reprocessing nuclear fuel

    International Nuclear Information System (INIS)

    The development of centrifugal separators has been a key ingredient in improving the process used for reprocessing of spent nuclear fuel. The separators are used to segregate uranium and plutonium from the fission products produced by a controlled nuclear reaction. The separators are small variable speed centrifuges, designed to operate in a harsh environment. Dynamic problems were detected by vibration analysis and resolved using modal analysis and trending. Problems with critical speeds, resonances in the base, balancing, weak components, precision manufacturing, and short life have been solved

  2. Vacuum-arc plasma centrifuge applied to stable isotope separation

    International Nuclear Information System (INIS)

    This work describes the results of a vacuum-arc plasma centrifuge experiment. A plasma centrifuge is an apparatus where a plasma column is produced due to the interaction of an electric current with an externally applied magnetic field, sup(→)J x sup(→)B. Among the applications of a rotating plasma, this work deals particularly with its utilization in an isotope enrichment device. The main characteristics of the plasma produced in this experiment are presented, with special attention to the plasma column rotation and the isotope enrichment. The analysis of the results is performed using a fluid model for a completely ionized rigid body rotating plasma column in steady state equilibrium. The main results are: a) rotation frequency of the plasma column in the range 2 x 10 sup(4) to 3 x 10 sup(5) rad/s; b) enrichment of 10 to 30% for the magnesium isotopes, and of 290 to 490% for the carbon 13 isotope; c) rigid body rotation of the plasma column only for radii smaller than the characteristic radius of the plasma column. re; d) linear dependence of the rotation frequency upon the magnetic field strength only for r < re; e) existence of an optimum value of the magnetic field for maximum enrichment; and f) dependence of the rotation frequency upon the inverse of the atomic mass. (author)

  3. Two-phase (bio)catalytic reactions in a table-top centrifugal contact separator

    NARCIS (Netherlands)

    Kraai, Gerard N.; Zwol, Floris van; Schuur, Boelo; Heeres, Hero J.; Vries, Johannes G. de

    2008-01-01

    A new spin on catalysis: A table-top centrifugal contact separator allows for fast continuous two-phase reactions to be performed by intimately mixing two immiscible phases and then separating them. Such a device has been used to produce biodiesel from sunflower oil and MeOH/NaOMe. A lipase-catalyze

  4. Novel highly integrated biodiesel production technology in a centrifugal contactor separator device

    NARCIS (Netherlands)

    Kraai, G. N.; Schuur, B.; van Zwol, F.; van de Bovenkamp, H. H.; Heeres, H. J.

    2009-01-01

    The base catalyzed production of biodiesel (FAME) from sunflower oil and methanol in a continuous centrifugal contactor separator (CCS) with integrated reaction and phase separation was studied. The effect of catalyst loading (sodium methoxide), temperature, rotational frequency and flow rates of th

  5. Carnosol purification. Scaling-up centrifugal partition chromatography separations.

    Science.gov (United States)

    Bouju, Elodie; Berthod, Alain; Faure, Karine

    2016-09-30

    This paper illustrates the application of a recently proposed protocol allowing the scale-up prediction on hydrostatic countercurrent chromatography columns (centrifugal partition chromatographs or CPC). A commercial extract of rosemary (Rosmarinus officinalis L.) was used as the starting material containing 0.48% of carnosol, an active pharmaceutical ingredient with great potential. After a rapid method development on a small-scale 35-mL CPC instrument that allowed for the determination of the solvent system and maximum sample concentration and volume, the purification was transferred on two larger instruments using the "free space between peaks" method. The method takes into account the technical limitations of the larger instruments, such as pressure and/or maximum centrifugal field, and allows, by simply running an analytical-sized injection on the large scale rotor, to give an accurate prediction of the maximum sample load and best throughput. The 0.27g of rosemary extract maximum load on a 35-mL CPC was transferred as a 1.9g load on a 254-mL medium size CPC and 9g load on a 812-mL CPC. The maximum process efficiency of 3.1mg of carnosol per hour obtained on the small 35-mL column was transferred on the 254-mL CPC giving 8.3mg/h and, on the larger 812-mL column 49.4mg of carnosol could be obtained per hour. If the scaling-up in CPC instruments is not directly homothetic, it can be highly predictable through a few simple experiments. PMID:27590084

  6. Carnosol purification. Scaling-up centrifugal partition chromatography separations.

    Science.gov (United States)

    Bouju, Elodie; Berthod, Alain; Faure, Karine

    2016-09-30

    This paper illustrates the application of a recently proposed protocol allowing the scale-up prediction on hydrostatic countercurrent chromatography columns (centrifugal partition chromatographs or CPC). A commercial extract of rosemary (Rosmarinus officinalis L.) was used as the starting material containing 0.48% of carnosol, an active pharmaceutical ingredient with great potential. After a rapid method development on a small-scale 35-mL CPC instrument that allowed for the determination of the solvent system and maximum sample concentration and volume, the purification was transferred on two larger instruments using the "free space between peaks" method. The method takes into account the technical limitations of the larger instruments, such as pressure and/or maximum centrifugal field, and allows, by simply running an analytical-sized injection on the large scale rotor, to give an accurate prediction of the maximum sample load and best throughput. The 0.27g of rosemary extract maximum load on a 35-mL CPC was transferred as a 1.9g load on a 254-mL medium size CPC and 9g load on a 812-mL CPC. The maximum process efficiency of 3.1mg of carnosol per hour obtained on the small 35-mL column was transferred on the 254-mL CPC giving 8.3mg/h and, on the larger 812-mL column 49.4mg of carnosol could be obtained per hour. If the scaling-up in CPC instruments is not directly homothetic, it can be highly predictable through a few simple experiments.

  7. Synthesis and refining of sunflower biodiesel in a cascade of continuous centrifugal contactor separators

    NARCIS (Netherlands)

    Bin Abu Ghazali, Yusuf; van Ulden, Wouter; van de Bovenkamp, Hendrik; Teddy, T; Picchioni, Francesco; Manurung, Robert; Heeres, Hero J.

    2015-01-01

    The synthesis of fatty acid methyl esters (FAME) from sunflower oil and methanol was studied in a continuous centrifugal contactor separator (CCCS) using sodium methoxide as the catalyst. The effect of relevant process variables like oil and methanol flow rate, rotational speed and catalyst concentr

  8. Process Intensification. Continuous Two-Phase Catalytic Reactions in a Table-Top Centrifugal Contact Separator

    NARCIS (Netherlands)

    Kraai, Gerard N.; Schuur, Boelo; van Zwol, Floris; Haak, Robert M.; Minnaard, Adriaan J.; Feringa, Ben L.; Heeres, Hero J.; de Vries, Johannes G.; Prunier, ML

    2009-01-01

    Production of fine chemicals is mostly performed in batch reactors. Use of continuous processes has many advantages which may reduce the cost of production. We have developed the use of centrifugal contact separators (CCSs) for continuous two-phase catalytic reactions. This equipment has previously

  9. Biodiesel synthesis from Jatropha curcas L. oil and ethanol in a continuous centrifugal contactor separator

    NARCIS (Netherlands)

    Abduh, Muhammad Yusuf; van Ulden, Wouter; Kalpoe, Vijay; van de Bovenkamp, Hendrik H.; Manurung, Robert; Heeres, Hero J.

    2013-01-01

    The synthesis of fatty acid ethyl esters (FAEE) from Jatropha curcas L. oil was studied in a batch reactor and a continuous centrifugal contactor separator (CCCS) using sodium ethoxide as the catalyst. The effect of relevant process variables like rotational speed, temperature, catalyst concentratio

  10. Gravitational and centrifugal oil-water separators with plate pack internals. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Plat, R.

    1994-05-16

    After some stages of treatment, most production water and other oily waste water is discharged into the sea or onto other surface water. To protect the environment, the total amount of oil discharged must be kept to a minimum. Legislation with regard to the discharge of oil into the sea is being pursued in an international context. One of these is the Paris Convention, covering regulations for discharges from both offshore and onshore operations in and around the North Sea; a limit of 40 ppm monthly average has been agreed. Concerning gravity and centrifugal separators, theoretical studies have been carried out with respect to oil-droplet shape, forces acting on oil droplets and interactions of oil droplets with oil-water interfaces. For these types of separators, oil-droplet diameters within the critical range may be assumed to be rigid spheres; Stokes' law is valid. A generally applicable separation efficiency function has been derived analytically, which is valid for gravity separators as well as centrifuges. Computer simulations and laboratory experiments support the predictions of this function. Gravity plate separators are among the most frequently applied separator types in the oil-industry. The gravity plate separator is relatively cheap compared to other types of separators, but it is heavy and bulky and cannot always reach the target effluent oil concentration of 40 ppm. The centrifuge is one of the best separators. It can meet the Paris Convention requirements and gives good performance in relation to required deck space and weight. The main disadvantage of the centrifuge is its high cost.

  11. Integrated reactor and centrifugal separator and uses thereof

    Science.gov (United States)

    Birdwell, Jr., Joseph F; Jennings, Harold L.; McFarlane, Joanna; Tsouris, Constantino

    2012-01-17

    An apparatus for providing reaction of fluids and separation of products with increased residence time. The apparatus includes a stationary shell, a rotating hollow cylindrical component disposed in the stationary shell, a residence-time increasing device external to the stationary shell, a standpipe for introducing fluid into an interior cavity of the hollow cylindrical component from the residence-time increasing device, a first outlet in fluid flow communication with the interior cavity of the hollow cylindrical component for a less dense phase fluid, and a second outlet in fluid flow communication with the interior cavity of the hollow cylindrical component for a more dense phase fluid.

  12. Centrifugal mass separation in rotating plasmas produced by a coaxial plasma gun

    International Nuclear Information System (INIS)

    Rotating Cu/Zn plasmas produced by a coaxial plasma gun have been applied to plasma centrifuge. A separation factor of up to 10 is measured over a radius of 4 cm when a current of 13 kA and an axial magnetic field of 2.5 kG are applied. Plasma parameters are: rotation frequency ω=1.1x106 rad/s, density n∼1015 cm-3, and ion temperature Ti=10 eV. The separation factor of 2 is attained even in the plasma core where the density is higher than one-half of the peak value. This is attributed to the fact that a strong centrifugal force forms a hollow density profile which gives the density peak at a radius of 2 cm

  13. Experimental Research on Desulfurization of Fine Coal Using an Enhanced Centrifugal Gravity Separator

    Institute of Scientific and Technical Information of China (English)

    TAO You-jun; LUO Zhen-fu; ZHAO Yue-min; TAO Daniel

    2006-01-01

    A desulphurization experimental study under the effects of compounding physical force fields has been described for < 0.5 mm fine particles of high sulfur coal. A statistical test using the Box-Behnken Design of experiments was conducted to evaluate the effects of individual operating variables and their interactions on desulfurization of fine coal using an enhanced centrifugal gravity separator. A model describing the relation between desulphurization efficiency of pyrite sulfur and different operating variables has been designed. The interactions between different factors on the pyrite sulfur desulphurization efficiency have been analysed. The optimal test conditions for desulfarization are extracted from the Design-Expert 6.0 software. Finally, the advantage of centrifugal gravity separation for fine coal is pointed out.

  14. Analysis and optimization of gas-centrifugal separation of uranium isotopes by neural networks

    Directory of Open Access Journals (Sweden)

    Migliavacca S.C.P.

    2002-01-01

    Full Text Available Neural networks are an attractive alternative for modeling complex problems with too many difficulties to be solved by a phenomenological model. A feed-forward neural network was used to model a gas-centrifugal separation of uranium isotopes. The prediction showed good agreement with the experimental data. An optimization study was carried out. The optimal operational condition was tested by a new experiment and a difference of less than 1% was found.

  15. A critical evaluation of Amicon Ultra centrifugal filters for separating proteins, drugs and nanoparticles in biosamples.

    Science.gov (United States)

    Johnsen, Elin; Brandtzaeg, Ole Kristian; Vehus, Tore; Roberg-Larsen, Hanne; Bogoeva, Vanya; Ademi, Ornela; Hildahl, Jon; Lundanes, Elsa; Wilson, Steven Ray

    2016-02-20

    Amicon(®) Ultra centrifugal filters were critically evaluated for various sample preparations, namely (a) proteome fractionation, (b) sample cleanup prior to liquid chromatography mass spectrometry (LC-MS) measurement of small molecules in cell lysate, and (c) separating drug-loaded nanoparticles and released drugs for accurate release profiling in biological samples. (a) Filters of supposedly differing molar mass (MM) selectivity (10, 30, 50 and 100K) were combined to attempt fractionation of samples of various complexity and concentration. However, the products had surprisingly similar MM retentate/filtrate profiles, and the filters were unsuited for proteome fractionation. (b) Centrifugal filtration was the only clean-up procedure in a FDA-guideline validated LC-MS method for determining anti-tuberculosis agents rifampicin and thioridazine in macrophage cell lysate. An additional organic solvent washing step (drug/protein-binding disruption) was required for satisfactory recovery. (c) The centrifugation filters are well suited for separating drugs and nanoparticles in simple aqueous solutions, but significantly less so for biological samples, as common drug-protein binding disruptors can dissolve NPs or be incompatible with LC-MS instrumentation.

  16. Designing and modeling a centrifugal microfluidic device to separate target blood cells

    Science.gov (United States)

    Shamloo, Amir; Selahi, AmirAli; Madadelahi, Masoud

    2016-03-01

    The objective of this study is to design a novel and efficient portable lab-on-a-CD (LOCD) microfluidic device for separation of specific cells (target cells) using magnetic beads. In this study the results are shown for neutrophils as target cells. However, other kinds of target cells can be separated in a similar approach. The designed microfluidics can be utilized as a point of care system for neutrophil detection. This microfluidic system employs centrifugal and magnetic forces for separation. After model validation by the experimental data in the literature (that may be used as a design tool for developing centrifugo-magnetophoretic devices), two models are presented for separation of target cells using magnetic beads. The first model consists of one container in the inlet section and two containers in the outlets. Initially, the inlet container is filled with diluted blood sample which is a mixture of red blood cells (RBCs) plus neutrophils which are attached to Magnetic beads. It is shown that by using centrifugal and magnetic forces, this model can separate all neutrophils with recovery factor of ~100%. In the second model, due to excess of magnetic beads in usual experimental analysis (to ensure that all target cells are attached to them) the geometry is improved by adding a third outlet for these free magnetic beads. It is shown that at angular velocity of 45 rad s-1, recovery factor of 100% is achievable for RBCs, free magnetic beads and neutrophils as target cells.

  17. Designing and modeling a centrifugal microfluidic device to separate target blood cells

    International Nuclear Information System (INIS)

    The objective of this study is to design a novel and efficient portable lab-on-a-CD (LOCD) microfluidic device for separation of specific cells (target cells) using magnetic beads. In this study the results are shown for neutrophils as target cells. However, other kinds of target cells can be separated in a similar approach. The designed microfluidics can be utilized as a point of care system for neutrophil detection. This microfluidic system employs centrifugal and magnetic forces for separation. After model validation by the experimental data in the literature (that may be used as a design tool for developing centrifugo-magnetophoretic devices), two models are presented for separation of target cells using magnetic beads. The first model consists of one container in the inlet section and two containers in the outlets. Initially, the inlet container is filled with diluted blood sample which is a mixture of red blood cells (RBCs) plus neutrophils which are attached to Magnetic beads. It is shown that by using centrifugal and magnetic forces, this model can separate all neutrophils with recovery factor of ∼100%. In the second model, due to excess of magnetic beads in usual experimental analysis (to ensure that all target cells are attached to them) the geometry is improved by adding a third outlet for these free magnetic beads. It is shown that at angular velocity of 45 rad s−1, recovery factor of 100% is achievable for RBCs, free magnetic beads and neutrophils as target cells. (paper)

  18. Mathematical Modeling of Non-Stationary Hydraulic Process Occurring in the Gas Centrifuge Cascade During the Separation of Multicomponent Isotope Mixtures

    Science.gov (United States)

    Orlov, A. A.; Ushakov, A. A.; Sovach, V. P.

    2016-08-01

    This article presents results of development of the mathematical model of nonstationary separation processes occurring in gas centrifuge cascades for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of germanium isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary separation processes in gas centrifuge cascades for separation of multicomponent isotope mixtures.

  19. An improved turbulence model for separation flow in a centrifugal pump

    Directory of Open Access Journals (Sweden)

    Yun Ren

    2016-06-01

    Full Text Available For the stable and reliable operation of centrifugal pump, the transient flow must be studied and the separation region should be avoided. Three-dimensional, incompressible, steady, and transient flows in a centrifugal pump at specific speed within 74 were numerically studied using shear stress transport k-ω turbulence model, and an improved explicit algebraic Reynolds stress model–rotation-curvature turbulence model was proposed by considering the effects of rotation and curvature in the impeller passages in this work. Steady and transient computations were conducted to compare with the experiments. The comparison of pump hydraulic performance showed that the explicit algebraic Reynolds stress model–rotation-curvature turbulence model was better than the original model, especially between 0.6QBEP and 1.2QBEP; the improved model could enhance the head prediction of pump by about 1%–7% than that with the original model. Then, the visualization of the vortex evolution was observed to validate the unsteady simulations. Good agreement was investigated between calculations and visualizations. It is indicated that the explicit algebraic Reynolds stress model–rotation-curvature model can successfully capture the separation flow.

  20. Fractional reactive extraction for symmetrical separation of 4-nitro-D,L-phenylalanine in centrifugal contactor separators: experiments and modeling.

    Science.gov (United States)

    Tang, Kewen; Wen, Ping; Zhang, Panliang; Huang, Yan

    2015-01-01

    The enantioselective liquid-liquid extraction of 4-nitro-D,L-phenylalanine (D,L-Nphy) using PdCl2 {(s)-BINAP} as extractant in dichloroethane was studied experimentally in a countercurrent cascade of 10 centrifugal contactor separators (CCSs) at 5°C, involving flow ratio, extractant concentration, and Cl(-) concentration. The steady-state enantiomeric excess (ee) in both stream exits was 90.86% at a 93.29% yield. The predicted value was modeled using an equilibrium stage approach. The correlation between model and experiment was satisfactory. The model was applied to optimize the production of both enantiomers in >97% ee and >99% ee. 14 stages and 16 stages are required for 97% ee and 99% ee for both enantiomers, respectively.

  1. Alternative separation steps for monoclonal antibody purification: combination of centrifugal partitioning chromatography and precipitation.

    Science.gov (United States)

    Oelmeier, Stefan A; Ladd-Effio, Christopher; Hubbuch, Jürgen

    2013-12-01

    Protein drugs continue to grow both in medicinal importance as in scale of their production. This furthers the interest in separation technologies that have the potential to replace chromatographic steps in a protein purification process. Two such unit operations that are employed in large scale in the chemical industry are extraction and precipitation. Their usefulness for the purification of proteins has been demonstrated, but the integration of such unit operations in a way that generate an output stream of high protein concentration and low process related impurities was missing. In this work, we employ centrifugal partitioning chromatography ('CPC') in combination with precipitation of the protein of interest to purify a cell culture supernatant of a monoclonal antibody producing cell line. Centrifugal partitioning chromatography was used as means of multi-step extraction using aqueous two-phase systems and was able to remove up to 88.2% of host cell protein ('HCP'). The following PEG driven precipitation and resolubilization of the protein of interest was use to condition the CPC output stream to suit subsequent chromatographic steps, to increase mAb concentration, remove the phase forming polymer, further improve HCP clearance, and integrate a low pH hold step for viral clearance. The entire process reduced HCP content by 99.4% while recovering 93% of the protein of interest. High throughput screening techniques were extensively employed during the development of the process.

  2. Separation of a binary mixture with a large mass difference between the components in a gas centrifuge

    OpenAIRE

    Abramov, Y. V.; Tokmantsev, V. I.

    2013-01-01

    The separation of a binary gaseous mixture of uranium hexafluoride 238UF6 with different light components in a high-speed centrifuge, intended for separating heavy isotopes, is examined. The mass of the light impurities is varied in the range M 1 = 0.02-0.349 kg/mole. It is shown that as the impurity mass decreases the structure of the flow fields in the centrifuge rotor changes considerably. If in the case of a mixture of heavy isotopes convective transport has a determining effect on the co...

  3. Preparative separation of glycoalkaloids α-solanine and α-chaconine by centrifugal partition chromatography.

    Science.gov (United States)

    Attoumbré, Jacques; Lesur, David; Giordanengo, Philippe; Baltora-Rosset, Sylvie

    2012-11-01

    The main glycoalkaloids of a commercial potato cultivar, α-chaconine and α-solanine, were extracted from sprouts of Solanum tuberosum cv. Pompadour by a mixture of MeOH/H(2)O/CH(3)COOH (400/100/50, v/v/v). In these conditions, 2.8±0.62g of crude extract were obtained from 50g of fresh sprouts and the total glycoalkaloid content was determined by analytical HPLC at 216.5mg/100g. α-Chaconine and α-solanine were separated in a preparative scale using centrifugal partition chromatography (CPC). In a solvent system composed of a mixture of ethyl acetate/butanol/water (15/35/50, v/v/v), α-chaconine (54mg) and α-solanine (15mg) were successfully isolated from the crude extract in one step of purification. The purity of isolated compounds was determined to be higher than 92% by HPLC analysis.

  4. Effect of Coriolis force on counter-current chromatographic separation by centrifugal partition chromatography.

    Science.gov (United States)

    Ikehata, Jun-Ichi; Shinomiya, Kazufusa; Kobayashi, Koji; Ohshima, Hisashi; Kitanaka, Susumu; Ito, Yoichiro

    2004-02-01

    The effect of Coriolis force on the counter-current chromatographic separation was studied using centrifugal partition chromatography (CPC) with four different two-phase solvent systems including n-hexane-acetonitrile (ACN); tert-butyl methyl ether (MtBE)-aqueous 0.1% trifluoroacetic acid (TFA) (1:1); MtBE-ACN-aqueous 0.1% TFA (2:2:3); and 12.5% (w/w) polyethylene glycol (PEG) 1000-12.5% (w/w) dibasic potassium phosphate. Each separation was performed by eluting either the upper phase in the ascending mode or the lower phase in the descending mode, each in clockwise (CW) and counterclockwise column rotation. Better partition efficiencies were attained by the CW rotation in both mobile phases in all the two-phase solvent systems examined. The mathematical analysis also revealed the Coriolis force works favorably under the CW column rotation for both mobile phases. The overall results demonstrated that the Coriolis force produces substantial effects on CPC separation in both organic-aqueous and aqueous-aqueous two-phase systems.

  5. Controllable Assembly and Separation of Colloidal Nanoparticles through a One-Tube Synthesis Based on Density Gradient Centrifugation.

    Science.gov (United States)

    Qi, Xiaohan; Li, Minglin; Kuang, Yun; Wang, Cheng; Cai, Zhao; Zhang, Jin; You, Shusen; Yin, Meizhen; Wan, Pengbo; Luo, Liang; Sun, Xiaoming

    2015-05-01

    Self-assembly of gold nanoparticles into one-dimensional (1D) nanostructures with finite primary units was achieved by introducing a thin salt (NaCl) solution layer into density gradient before centrifugation. The electrostatic interactions between Au nanoparticles would be affected and cause 1D assembly upon passing through the salt layer. A negatively charged polymer such as poly(acrylic acid) was used as an encapsulation/stabilization layer to help the formation of 1D Au assemblies, which were subsequently sorted according to unit numbers at succeeding separation zones. A centrifugal field was introduced as the external field to overcome the random Brownian motion of NPs and benefit the assembly effect. Such a facile "one-tube synthesis" approach couples assembly and separation in one centrifuge tube by centrifuging once. The method can be tuned by changing the concentration of interference salt layer, encapsulation layer, and centrifugation rate. Furthermore, positively charged fluorescent polymers such as perylenediimide-poly(N,N-diethylaminoethyl methacrylate) could encapsulate the assemblies to give tunable fluorescence properties. PMID:25809533

  6. Feedback Control and Dynamic Behaviour of Z-Source Converter Fed Separately Excited DC Motor and Centrifugal Pump Set

    Directory of Open Access Journals (Sweden)

    Saswati Swapna Dash

    2014-07-01

    Full Text Available This paper presents an overall study of Feedback Control of Z-Source Converter Fed Separately excited DC motor with centrifugal Pump Set. Z-source converter can be used for both voltage buck and boost mode using LC impedance network. In this paper the dynamic modeling of Z-source with motor load and centrifugal pump set is carried out with new findings. The compensators for speed feedback loop are designed by taking average state space analysis and small signal model of the system. The feedback loop is designed by classical control methods. The experiment is done in MATLAB work environment and the result is verified by Simulation.

  7. Feedback Control and Dynamic Behaviour of Z-Source Converter Fed Separately Excited DC Motor and Centrifugal Pump Set

    OpenAIRE

    Saswati Swapna Dash; Byamakesh Nayak; Subrat Kumar

    2014-01-01

    This paper presents an overall study of Feedback Control of Z-Source Converter Fed Separately excited DC motor with centrifugal Pump Set. Z-source converter can be used for both voltage buck and boost mode using LC impedance network. In this paper the dynamic modeling of Z-source with motor load and centrifugal pump set is carried out with new findings. The compensators for speed feedback loop are designed by taking average state space analysis and small signal model of the system. The feedba...

  8. SiO2/polyacrylonitrile membranes via centrifugal spinning as a separator for Li-ion batteries

    Science.gov (United States)

    Yanilmaz, Meltem; Lu, Yao; Li, Ying; Zhang, Xiangwu

    2015-01-01

    Centrifugal spinning is a fast, cost-effective and safe alternative to the electrospinning technique, which is commonly used for making fiber-based separator membranes. In this work, SiO2/polyacrylonitrile (PAN) membranes were produced by using centrifugal spinning and they were characterized by using different electrochemical techniques for use as separators in Li-ion batteries. SiO2/PAN membranes exhibited good wettability and high ionic conductivity due to their highly porous fibrous structure. Compared with commercial microporous polyolefin membranes, SiO2/PAN membranes had larger liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO2/PAN membrane separators were assembled into lithium/lithium iron phosphate cells and these cells delivered high capacities and exhibited good cycling performance at room temperature. In addition, cells using SiO2/PAN membranes showed superior C-rate performance compared to those using microporous PP membrane.

  9. Separation of Protein Crystals from Spores of Bacillus thuringiensis by Ludox Gradient Centrifugation

    OpenAIRE

    Zhu, Yu Sheng; Brookes, Allan; Carlson, Ken; Filner, Philip

    1989-01-01

    A method is described for the purification of Bacillus thuringiensis protein crystals by Ludox gradient centrifugation. This method is simple, inexpensive, fast, and efficient compared with other techniques. It has been successfully used to purify and characterize the protein crystals from several B. thuringiensis strains.

  10. The plasma centrifuge: A compact, low cost, stable isotope separator. Phase 2 final technical report, September 15, 1991 - September 14, 1995

    International Nuclear Information System (INIS)

    Enriched stable isotopes are required for production of radionuclides as well as for research and diagnostic uses. Science Research Laboratory (SRL) has developed a plasma centrifuge for moderate throughput of enriched stable isotopes, such as 13C, 17O, 18O, and 203Tl, for medical as well as other applications. Dwindling isotope stocks have restricted the use of enriched isotopes and their associated labeled organic molecules in medical imaging to very few research facilities because of high costs of isotope separation. With the introduction of the plasma centrifuge separator, the cost per separated gram of even rarely occurring isotopes (≤ 1% natural abundance) is potentially many times lower than with other separation technologies (cryogenic distillation and calutrons). The centrifuge is a simple, robust, pulsed electrical discharge device that has successfully demonstrated isotope separation of small (mg) quantities of 26Mg. Based on the results of the Phase 2 program, modest enhancements to the power supplies and cooling systems, a centrifuge separator will have high repetition rate (60 pps) and high duty cycle (60%) to produce in one month kilogram quantities of highly enriched stable isotopes. The centrifuge may be used in stand-alone operation or could be used as a high-throughput pre-separation stage with calutrons providing the final separation

  11. Centrifugal reciprocating compressor

    Science.gov (United States)

    High, W. H.

    1980-01-01

    Efficient compressor uses centrifugal force to compress gas. System incorporates two coupled dc motors, each driving separate centrifugal reciprocating-compressor assembly. Motors are synchronized to accelerate and decelerate alternately.

  12. The Structure of Centrifugal Separator and its Control System%离心选矿机结构及其控制方法

    Institute of Scientific and Technical Information of China (English)

    李华杰

    2012-01-01

    Centrifugal separator is a kind of gravity separation equipment developed in the 1960s for dressing of low-grade and fine grained mineral. With the progress of technology, the integrated ore dressing technology with centrifugal separator has been gradually improved. The application of advanced automatic control technology make the working process of centrifugal separator more reliable and convenient, which greatly enhanced ore dressing performance of centrifugal separator. This article introduces the structure, components, working principle and automatic control system of centrifugal separator.%离心选矿机是国内60年代研制出的一种重选设备,适用于低品位、细粒级的钨矿石选别.随着技术的进步,离心选矿机选矿的综合技术日趋完善,特别是先进的自动控制技术的应用,使得离心选矿机的工作过程稳定可靠、调节方便,大大提升了离心选矿机的选矿效果.本文介绍了离心选矿机的结构组成、工作原理和自动控制系统.

  13. Boundary-value problem for a counterrotating electrical discharge in an axial magnetic field. [plasma centrifuge for isotope separation

    Science.gov (United States)

    Hong, S. H.; Wilhelm, H. E.

    1978-01-01

    An electrical discharge between two ring electrodes embedded in the mantle of a cylindrical chamber is considered, in which the plasma in the anode and cathode regions rotates in opposite directions under the influence of an external axial magnetic field. The associated boundary-value problem for the coupled partial differential equations describing the azimuthal velocity and radial current-density fields is solved in closed form. The velocity, current density, induced magnetic induction, and electric fields are presented for typical Hartmann numbers, magnetic Reynolds numbers, and geometry parameters. The discharge is shown to produce anodic and cathodic plasma sections rotating at speeds of the order 1,000,000 cm/sec for conventional magnetic field intensities. Possible application of the magnetoactive discharge as a plasma centrifuge for isotope separation is discussed.

  14. Iodixanol Gradient Centrifugation to Separate Components of the Low-Density Membrane Fraction from 3T3-L1 Adipocytes.

    Science.gov (United States)

    Sadler, Jessica B A; Lamb, Christopher A; Gould, Gwyn W; Bryant, Nia J

    2016-02-01

    We optimized a set of fractionation techniques to facilitate the isolation of subcellular compartments containing insulin-sensitive glucose transporter isoform 4 (GLUT4), which is mobilized from GLUT4 storage vesicles (GSVs) in fat and muscle cells in response to insulin. In the absence of insulin, GLUT4 undergoes a continuous cycle of GSV formation and fusion with other compartments. Full membrane fractionation of 3T3-L1 adipocytes produces a low-density membrane fraction that contains both the constitutive recycling pool (the endosomal recycling compartments) and the insulin-sensitive pool (the GSVs). These two pools can be separated based on density using iodixanol gradient centrifugation, described here. PMID:26832683

  15. Separation of Aeruginosin-865 from Cultivated Soil Cyanobacterium (Nostoc sp.) by Centrifugal Partition Chromatography combined with Gel Permeation Chromatography.

    Science.gov (United States)

    Cheel, José; Minceva, Mirjana; Urajová, Petra; Aslam, Rabya; Hrouzek, Pavel; Kopecký, Jiří

    2015-10-01

    Aeruginosin-865 was isolated from cultivated soil cyanobacteria using a combination of centrifugal partition chromatography (CPC) and gel permeation chromatography. The solubility of Aer-865 in different solvents was evaluated using the conductor-like screening model for real solvents (COSMO-RS). The CPC separation was performed in descending mode with a biphasic solvent system composed of water-n-BuOH-acetic acid (5:4:1, v/v/v). The upper phase was used as a stationary phase, whereas the lower phase was employed as a mobile phase at a flow rate of 10 mL/min. The revolution speed and temperature of the separation column were 1700 rpm and 25 degrees C, respectively. Preparative CPC separation followed by gel permeation chromatography was performed on 50 mg of crude extract yielding Aer-865 (3.5 mg), with a purity over 95% as determined by HPLC. The chemical identity of the isolated compound was confirmed by comparing its spectroscopic data (UV, HRESI-MS, HRESI-MS/MS) with those of an authentic standard and data available in the literature. PMID:26669111

  16. Effect of combined density gradient centrifugation on X- and Y- sperm separation and chromatin integrity

    OpenAIRE

    Tahereh Esmaeilpour; Leila Elyasi; Soghra Bahmanpour; Alireza Ghannadi; Ahmad Monabbati; Farzaneh Dehghani; Marjaneh Kazerooni

    2012-01-01

    Background: It has been claimed that by using different washing methods, the sperms can be separated according to size, motility, density, chromosomal content and surface markings and charge. These methods also reduce sperm chromatin deficiencies and screen the sperms before applying in assisted reproduction techniques. Objective: This study compared simple density gradient methods and a combined method with albumin density gradient and PureSperm separation (alb/PureSperm) for sex preselectio...

  17. Separation of mitochondria from contaminating subcellular structures utilizing silica sol gradient centrifugation.

    Science.gov (United States)

    Jackson, C; Dench, J E; Hall, D O; Moore, A L

    1979-07-01

    Discontinuous Percoll density gradients have been developed for the purification of mitochondria, permitting rapid separation under isosmotic and low viscosity conditions. Mitochondria from several etiolated tissues have been successfully separated from contaminating subcellular structures by this method. For potato tuber the ratio of washed to purified mitochondrial protein was 2.6, similar to the increase in specific activity of cytochrome c oxidase following separation. The purification of mitochondria from green leaf tissues on Percoll gradients has reduced chlorophyll contamination of spinach mitochondria from about 70 micrograms chlorophyll per milligram protein to approximately 8 micrograms chlorophyll per milligram protein.The ratio of protein content of the washed mitochondria compared to that in the purified preparation was 7 for spinach and respiratory activity was retained. The physiological integrity and oxidative properties of washed and gradient mitochondria are compared. PMID:16660904

  18. Isotopic separation by centrifugation. Rotating plasma; Separacion Isotopic por Centrifugacion Plasma Rotante

    Energy Technology Data Exchange (ETDEWEB)

    Perello, M.; Vigon, M. A.

    1972-07-01

    The motion of a gas simultaneously submitted to an electric discharge and magnetic field has been studied in order to analyze the possibility of producing isotopes separation by rotation of a plasma. Some experimental results obtained under different discharge conditions are also given. Differences of pressure up to 15 mm oil between both electrodes has been attained. No definite conclusion on separation factors could be reached because of the low reproducibility of results, probably due to the short duration of the discharge with a new chamber designed to support stronger thermal shocks more reliable data can be expected. (Author) 16 refs.

  19. Experimental and Model Studies on Continuous Separation of 2-Phenylpropionic Acid Enantiomers by Enantioselective Liquid-Liquid Extraction in Centrifugal Contactor Separators.

    Science.gov (United States)

    Feng, Xiaofeng; Tang, Kewen; Zhang, Pangliang; Yin, Shuangfeng

    2016-03-01

    Multistage enantioselective liquid-liquid extraction (ELLE) of 2-phenylpropionic acid (2-PPA) enantiomers using hydroxypropyl-β-cyclodextrin (HP-β-CD) as extractant was studied experimentally in a counter-current cascade of centrifugal contactor separators (CCSs). Performance of the process was evaluated by purity (enantiomeric excess, ee) and yield (Y). A multistage equilibrium model was established on the basis of single-stage model for chiral extraction of 2-PPA enantiomers and the law of mass conservation. A series of experiments on the extract phase/washing phase ratio (W/O ratio), extractant concentration, the pH value of aqueous phase, and the number of stages was conducted to verify the multistage equilibrium model. It was found that model predictions were in good agreement with the experimental results. The model was applied to predict and optimize the symmetrical separation of 2-PPA enantiomers. The optimal conditions for symmetric separation involves a W/O ratio of 0.6, pH of 2.5, and HP-β-CD concentration of 0.1 mol L(-1) at a temperature of 278 K, where eeeq (equal enantiomeric excess) can reach up to 37% and Yeq (equal yield) to 69%. By simulation and optimization, the minimum number of stages was evaluated at 98 and 106 for eeeq > 95% and eeeq > 97%.

  20. Experimental and modelling studies on continuous synthesis and refining of biodiesel in a dedicated bench scale unit using centrifugal contactor separator technology

    NARCIS (Netherlands)

    Abduh, Muhammad Yusuf; Martinez, Alberto Fernandez; Kloekhorst, Arjan; Manurung, Robert; Heeres, Hero J.

    2016-01-01

    Continuous synthesis and refining of biodiesel (FAME) using a laboratory scale bench scale unit was explored. The unit consists of three major parts: (i) a continuous centrifugal contactor separator (CCCS) to perform the reaction between sunflower oil and methanol; (ii) a washing unit for the crude

  1. High-speed, high-purity separation of gold nanoparticle-DNA origami constructs using centrifugation.

    Science.gov (United States)

    Ko, Seung Hyeon; Vargas-Lara, Fernando; Patrone, Paul N; Stavis, Samuel M; Starr, Francis W; Douglas, Jack F; Liddle, J Alexander

    2014-10-01

    DNA origami is a powerful platform for assembling gold nanoparticle constructs, an important class of nanostructure with numerous applications. Such constructs are assembled by the association of complementary DNA oligomers. These association reactions have yields of 90%. The gold nanoparticles play a number of critical roles in our system, functioning not only as integral components of the purified products, but also as hydrodynamic separators and optical indicators of the reaction products during the purification process. We find that separation resolution is ultimately limited by the polydispersity in the mass of the gold nanoparticles and by structural distortions of DNA origami induced by the gold nanoparticles. Our study establishes a methodology for determining the design rules for nanomanufacturing DNA origami-nanoparticle constructs.

  2. Centrifugal pyrocontactor

    Science.gov (United States)

    Chow, Lorac S.; Leonard, Ralph A.

    1993-01-01

    A method for mixing and separating immiscible liquid salts and liquid metals in a centrifugal contractor. The method includes introducing the liquids into an annular mixing zone and intensely mixing the liquids using vertical vanes attached to a rotor cooperating with vertical baffles, a horizontal baffle, and bottom vanes attached to the contactor housing. The liquids enter the contactor in the range of 700-800 degrees Celsius. The liquids are separated in the rotor into a dense phase and a light phase which are discharged from the contactor.

  3. Single-layer centrifugation separates spermatozoa from diploid cells in epididymal samples from gray wolves, Canis lupus (L.).

    Science.gov (United States)

    Muñoz-Fuentes, Violeta; Linde Forsberg, Catharina; Vilà, Carles; Morrell, Jane M

    2014-09-15

    Sperm samples may be used for assisted reproductive technologies (e.g., farmed or endangered species) or as a source of haploid DNA or sperm-specific RNA. When ejaculated spermatozoa are not available or are very difficult to obtain, as is the case for most wild endangered species, the epididymides of dead animals (e.g., animals that have been found dead, shot by hunters or poachers, or that that require euthanasia in zoological collections) can be used as a source of sperm. Such epididymal sperm samples are usually contaminated with cellular debris, erythrocytes, leukocytes, and sometimes also bacteria. These contaminants may be sources of reactive oxygen species that damage spermatozoa during freezing or contribute undesired genetic material from diploid cells. We used single-layer centrifugation through a colloid formulation, Androcoll-C, to successfully separate wolf epididymal spermatozoa from contaminating cells and cellular debris in epididymal samples harvested from carcasses. Such a procedure may potentially be applied to epididymal sperm samples from other species. PMID:25028195

  4. Microwave assisted centrifuge and related methods

    Science.gov (United States)

    Meikrantz, David H [Idaho Falls, ID

    2010-08-17

    Centrifuge samples may be exposed to microwave energy to heat the samples during centrifugation and to promote separation of the different components or constituents of the samples using a centrifuge device configured for generating microwave energy and directing the microwave energy at a sample located in the centrifuge.

  5. Generation of diversiform gold nanostructures inspired by honey's components: growth mechanism, characterization, and shape separation by the centrifugation-assisted sedimentation.

    Science.gov (United States)

    Snitka, Valentinas; Naumenko, Denys O; Ramanauskaite, Lina; Kravchenko, Sergiy A; Snopok, Boris A

    2012-11-15

    The green synthesis of irregular-shaped nanomaterials used for various applications in nanoplasmonics, medicine, and biotechnology creates an economical and environmental challenge. We describe the rapid wet-chemical approach to synthesis of stable and water-soluble gold nanostructues at room temperature. In addition to spherical and road-like nanoparticles, gold decahedra and triangular plates were grown using the one-step synthesis process of HAuCl(4) in the presence of honey, in which main components act as reducing (glucose) and stabilizing (fructose) agents; the mechanism of the process is discussed in details. The requirements for anisotropic phase boundaries for generation of polyhedral gold nanocrystals in solutions are highlighted. The synthesis, morphology, and separation procedure of gold nanoparticles are examined using the techniques of optical spectroscopy, transmission electron microscopy, and atomic force microscopy. We demonstrate that centrifugation can be used for efficient separation of nanoparticles with different shapes from a mixture. It was found that while centrifuging, the spheres sediment at the bottom of the tube, segregating from rods that form a deposit on the side wall, whereas polygons remain in the solution. PMID:22918048

  6. Intensified Separation of Steviol Glycosides from a Crude Aqueous Extract of Stevia rebaudiana Leaves Using Centrifugal Partition Chromatography.

    Science.gov (United States)

    Hubert, Jane; Borie, Nicolas; Chollet, Sébastien; Perret, Joël; Barbet-Massin, Claire; Berger, Monique; Daydé, Jean; Renault, Jean-Hugues

    2015-11-01

    Aqueous extracts of Stevia rebaudiana leaves have been approved since 2008 by the Joint Expert Committee for Food Additives as sugar substitutes in many food and beverages in Western and Far East Asian countries. The compounds responsible for the natural sweetness of Stevia leaves include a diversity of diterpenoid glycosides derived from a steviol skeleton. These steviol glycosides also exhibit a low calorific value as well as promising therapeutic applications, particularly for the treatment of sugar metabolism disturbances. In this work, centrifugal partition chromatography is proposed as an efficient technical alternative to purify steviol glycosides from crude aqueous extracts of Stevia leaves on a multigram scale. Two different commercial instruments, including an ASCPC250® and a FCPE300® made of columns containing 1890 and 231 twin-cells, respectively, were evaluated and compared. All experiments were performed with a polar biphasic solvent system composed of ethyl acetate, n-butanol, and water in a gradient elution mode. When using the 1890 partition cell centrifugal partition chromatography column of 250 mL, 42 mg of stevioside, 68 mg of dulcoside A, and 172 mg of rebaudioside A, three major constituents of the initial extract were obtained from 1 g of the initial mixture at purities of 81%, 83%, and 99%, respectively. The productivity was further improved by intensifying the procedure on the 231 partition cell centrifugal partition chromatography column of 303 mL with the sample mass loading increased up to 5 g, resulting in the recovery of 1.2 g of stevioside, 100 mg of dulcoside A, and 1.1 g of rebaudioside A at purities of 79%, 62%, and 98%, respectively. The structures of the isolated compounds were validated by HPLC-UV, ESI-MS, (1)H, and (13)C NMR analyses. Altogether, the results demonstrate that the column design (i.e., the partition cell number) is an important aspect to be considered for a larger scale centrifugal partition chromatography

  7. Intensified Separation of Steviol Glycosides from a Crude Aqueous Extract of Stevia rebaudiana Leaves Using Centrifugal Partition Chromatography.

    Science.gov (United States)

    Hubert, Jane; Borie, Nicolas; Chollet, Sébastien; Perret, Joël; Barbet-Massin, Claire; Berger, Monique; Daydé, Jean; Renault, Jean-Hugues

    2015-11-01

    Aqueous extracts of Stevia rebaudiana leaves have been approved since 2008 by the Joint Expert Committee for Food Additives as sugar substitutes in many food and beverages in Western and Far East Asian countries. The compounds responsible for the natural sweetness of Stevia leaves include a diversity of diterpenoid glycosides derived from a steviol skeleton. These steviol glycosides also exhibit a low calorific value as well as promising therapeutic applications, particularly for the treatment of sugar metabolism disturbances. In this work, centrifugal partition chromatography is proposed as an efficient technical alternative to purify steviol glycosides from crude aqueous extracts of Stevia leaves on a multigram scale. Two different commercial instruments, including an ASCPC250® and a FCPE300® made of columns containing 1890 and 231 twin-cells, respectively, were evaluated and compared. All experiments were performed with a polar biphasic solvent system composed of ethyl acetate, n-butanol, and water in a gradient elution mode. When using the 1890 partition cell centrifugal partition chromatography column of 250 mL, 42 mg of stevioside, 68 mg of dulcoside A, and 172 mg of rebaudioside A, three major constituents of the initial extract were obtained from 1 g of the initial mixture at purities of 81%, 83%, and 99%, respectively. The productivity was further improved by intensifying the procedure on the 231 partition cell centrifugal partition chromatography column of 303 mL with the sample mass loading increased up to 5 g, resulting in the recovery of 1.2 g of stevioside, 100 mg of dulcoside A, and 1.1 g of rebaudioside A at purities of 79%, 62%, and 98%, respectively. The structures of the isolated compounds were validated by HPLC-UV, ESI-MS, (1)H, and (13)C NMR analyses. Altogether, the results demonstrate that the column design (i.e., the partition cell number) is an important aspect to be considered for a larger scale centrifugal partition chromatography

  8. Centrifugal pumps

    CERN Document Server

    Anderson, HH

    1981-01-01

    Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

  9. Temporal behaviour of a corner separation in a radial vaned diffuser of a centrifugal compressor operating near surge

    Science.gov (United States)

    Marsan, A.; Trébinjac, I.; Coste, S.; Leroy, G.

    2013-12-01

    The temporal behaviour of a flow separation in the hub-suction side corner of a transonic diffuser is studied thanks to unsteady numerical simulations based on the phase-lagged approach. The validity of the numerical results is confirmed by comparison with experimental unsteady pressure measurements. An analysis of the instantaneous skin-friction pattern and particles trajectories is presented. It highlights the topology of the separation and its temporal behaviour. The major result is that, despite of a highly time-dependent core flow, the separation is found to be a "fixed unsteady separation" characterized by a fixed location of the main saddle of the separation but an extent of the stall region modulated by the pressure waves induced by the impeller-diffuser interaction.

  10. Chiral magnetic microspheres purified by centrifugal field flow fractionation and microspheres magnetic chiral chromatography for benzoin racemate separation

    OpenAIRE

    Tian, Ailin; Qi, Jing; Liu, Yating; Wang, Fengkang; Ito, Yoichiro; Wei, Yun

    2013-01-01

    Separation of enantiomers still remains a challenge due to their identical physical and chemical properties in a chiral environment, and the research on specific chiral selector along with separation techniques continues to be conducted to resolve individual enantiomers. In our laboratory the promising magnetic chiral microspheres Fe3O4@SiO2@cellulose-2, 3-bis (3, 5-dimethylphenylcarbamate) have been developed to facilitate the resolution using both its magnetic property and chiral recognitio...

  11. Fundamental investigation on interaction forces in bubble swarms and its application to the design of centrifugal separators

    International Nuclear Information System (INIS)

    The present investigation deals with two aspects of gas-liquid flows, viz. interaction forces between the phases in bubble swarms and numerical description of rotating gas-liquid flows. The insight obtained was applied to the development of axial gas-liquid cyclones, as used i.a. as primary separators in nuclear boiling water reactors. (Auth.)

  12. 微灌离心分离器内部流场分布数值模拟%Numerical simulation of flow field distribution in centrifugal separator for micro-irrigation

    Institute of Scientific and Technical Information of China (English)

    邱元锋; 孟戈; 罗金耀

    2015-01-01

    在缺水地区,利用高含沙水作为微灌水源的条件下,低浓度混合多相流模型已不能适用于微灌用离心分离器的数值模拟。该文以高含沙水作为微灌水源,结合离心分离器的结构参数,在流体力学基本方程基础上,通过网格划分和边界条件设定,采用有限体积法进行离散和求解,控制方程采用k-ε模型模拟分析了离心分离器的内部流场特征,并通过试验验证数值模拟成果,模拟值与试验实测值相对误差在10%以内,说明数值模拟采用的算法和模型是合理的。在试验验证的基础上,模拟分析了高含沙水为微灌水源的条件下,离心分离器的速度、湍动能以及静压分布,结果表明:离心分离器内速度分布主要有切向速度、轴向速度和径向速度,沿径向方向具有一定的对称性;离心分离器内湍动能分布具有一定的对称性,由轴中间向器壁两侧逐渐变小;静压分布具有一定的对称性性,由器壁两侧向轴中心逐渐减少。结果可为微灌用离心分离器特性参数的优化提供依据。%Centrifugal separator is one kind of filtration equipment that can separate the sediment from high-silt content water based on principles of rotational flow and centrifugal force. In recent years, research on numerical simulation of centrifugal separator is mostly in the fields of petroleum and chemical industry, and focuses on low concentration and mixture multiphase flow model. When using high-silt content water as micro-irrigation water source in water shortage areas, there will be high-silt content water near the centrifugal separator wall and underflow, in such case, low concentration and mixture multiphase flow model is not applicable to the numerical simulation of centrifugal separator that has used for micro-irrigation. Using high-silt content water as micro-irrigation water source, combined with the structure parameters of

  13. Factors Influencing the Separation Efficiency of Disc Centrifuge for Natural Latex%天然胶乳碟式离心机分离效率的影响因素

    Institute of Scientific and Technical Information of China (English)

    杨耀华; 李宗良

    2014-01-01

    The working principle of the disc centrifuge model LX-460 for separation of natural latex was brielfy introduced. The factors inlfuencing the separation efifciency such as regulator combination, separation time, solid content of fresh latex and centrifuge type were studied. The experimental results showed that there was an optimum length for the regulator screw when the separation efifciency was high. The efifciency could be reduced when the time was prolonged or the solid content of the latex increased. The centrifuge type also had an inlfuence on the separation efifciency. In order to improve the efifciency, it was recommended to establish standard processing parameters and separation time, control the quality of fresh latex, maintain the centrifuge in good condition, and strengthen personnel training.%简述LX-460型天然胶乳碟式离心机的工作原理,考察离心机调节器组合、分离时间、新鲜胶乳干胶浓度、离心机型号对天然胶乳离心分离效率的影响。结果表明:调节螺丝长度适当,分离效率较高;分离时间延长,分离效率降低;新鲜胶乳干胶含量越大,分离效率降低;离心机型号对分离效果有一定的影响。确定合理的工艺参数和分离时间、控制新鲜胶乳质量、良好维护离心机、加强操作人员培训是提高离心机分离效率的重要措施。

  14. Evaluation of real-time PCR coupled with immunomagnetic separation or centrifugation for the detection of healthy and sanitizer-injured Salmonella spp. on mung bean sprouts.

    Science.gov (United States)

    Zheng, Qianwang; Mikš-Krajnik, Marta; Yang, Yishan; Lee, Sang-Myun; Lee, Seung-Cheol; Yuk, Hyun-Gyun

    2016-04-01

    Fresh mung bean sprouts have been identified as a source of many Salmonella outbreaks worldwide. The aim of this study was to develop a rapid and accurate detection methodology for low levels of healthy and sanitizer-injured Salmonella on mung bean sprouts using real-time PCR coupled with either immunomagnetic separation (PCR-IMS) or centrifugation (PCR-cen). Initially, three parameters of IMS; specificity/sensitivity, bacterial concentration and bead incubation time were optimized. Secondly, limit of detection (LOD) was determined for the optimized PCR-IMS and PCR-cen. These two methods were compared against PCR alone (PCR) and the standard culture method (ISO) for their ability to detect Salmonella using inoculated and uninoculated sprouts. Under optimum IMS conditions (10(5)CFU/ml for 30 min), capture efficiency of Salmonella in sprout suspensions was lower than 40%, most probably due to the non-specific binding of the background microbiota. PCR-IMS and PCR-cen had a similar LOD at 10(3)CFU/ml, which was one log unit lower than PCR. Enrichment of 10h was sufficient to detect 100% of the inoculated sprouts with both PCR-IMS and PCR-cen, which was significantly faster compared to PCR and the ISO method. Moreover, the validation study using uninoculated sprouts revealed that PCR-IMS and PCR-cen were equally effective on Salmonella detection, showing 98.3% accuracy. These results suggest that PCR-cen would be the effective and less costly method for the detection of both healthy and sanitizer-injured Salmonella on mung bean sprouts.

  15. Centrifugal Sieve for Size-Segregation/ Beneficiation of Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilizing centrifugal force as the primary body-force, combined with both shearing flow and vibratory motion the proposed centrifugal-sieve separators can provide...

  16. Numerical Simulation of Separation Process in a Two-Stage Pusher Centrifuge%双级活塞推料离心机分离过程的数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    谭蔚; 逄翀; 沙恩典; 陶渊卿

    2013-01-01

    The two-stage pusher centrifuge is a kind of continuous operation centrifuges, and is widely used in light industry, chemical industry, metallurgy, coal and other industries. As the first-stage drum does rotation movement and reciprocating motion at the same time, the fluid flow in it is extremely complex, and there is no yet theoretical method to describe the filtration separation process. Therefore, taking a p-100-type two-stage pusher centrifuge for example, this paper used FLUENT software to simulate it and to obtain the fluid flow situation within the centrifuge drum. At the same time, the feeding concentration and drum rotational speed parameters were changed to examine the influence of them on centrifuge separation. The results show that, as the feed concentration increases, the cake solids content, the recovery ratio of solid phase and the solid containing ratio of supernatant show the trend of becoming larger, while the initial time for the centrifuge separation to reach its stable state and the initial axial coordinate for the cake to reach its maximum solid content are reduced; with increasing rational speed, the recovery ratio of solid phase, the solid containing ratio of supernatant and the axial coordinate of the cake reach its maximum solid content become gradually smaller, while cake solid content is increasing, and there is no specific rule for the initial time of the centrifuge separation to reach its stable state. The results provide a series of references to optimize the design of the centrifuge structure.%双级活塞推料离心机是连续操作的离心机的一种,广泛应用于轻工、化工、冶金、煤炭等行业。双级活塞推料离心机的一级转鼓由于在旋转运动的同时又进行往复运动,流体在转鼓内的流动过程极为复杂,尚没有理论方法能够描述其过滤分离的过程。以P-100型双级活塞推料离心机为例,运用FLUENT软件进行数值模拟,得到了离心机转鼓内

  17. Centrifugal pumps

    CERN Document Server

    Gülich, Johann Friedrich

    2014-01-01

    This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

  18. Detection methods for centrifugal microfluidic platforms

    DEFF Research Database (Denmark)

    Burger, Robert; Amato, Letizia; Boisen, Anja

    2016-01-01

    Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation...... for the centrifugal microfluidics platform and cover optical as well as mechanical and electrical detection principles....

  19. Centrifugation. A theoretical study of oxygen enrichment by centrifugation

    Energy Technology Data Exchange (ETDEWEB)

    Kierkegaard, P.; Raetz, E.

    1998-12-01

    In the present paper we first investigate what happens if we fill a cylinder with air, close it and rotate it. The results show that no matter which peripheral speed is used, it is not possible by means of the radial separation effect alone, to enrich the oxygen concentration from the previous 21% to more then 23.3%, which is of no practical value. In case of a too low enrichment in one centrifuge, the wanted material from this centrifuge can be used as an input for a second centrifuge and so on, in this way forming a cascade of centrifuges. Oxygen will be enriched in each step, until the desired concentration is reached. Cascading was the technology in the very beginning by enrichment plants for uraniumhexaflouride, used for atomic weapons and nuclear power plants. In this study we try to avoid cascading by aiming for higher separation factors. Therefore, we next investigate the possibilities of using a countercurrent centrifuge where in principle the enriched gas is subjected to several centrifugation in the same centrifuge. The calculations show, that in this way it is possible to produce nearly a 100% pure oxygen (polluted with some heavier molecules like argon) in one machine. Our third step was to calculate the amount of oxygen produced per hour. Using a countercurrent centrifuge of the Zippe type, 100 cm high and 20 cm in diameter, it is or will be possible in the near future to produce 17 g enriched air per hour enriched to 50% oxygen. That corresponds to processing 1 m{sup 3} atmospherical air in the period of approximately 24 hours. This is not very impressive. Our fourth step was to estimate the amount of power used for producing this amount of oxygen. A rough, but complicated, estimate shows that the power consumption at the production level will be about the double of the consumption used today. The overall conclusion is, that centrifugation as a production method for oxygen (or nitrogen) will not be competitive with the currently used method in the

  20. Comparison and Selection of Centrifugal Compressor in Large Air Separation Plant%大型空分装置配套离心压缩机组的综合选评

    Institute of Scientific and Technical Information of China (English)

    邱水金; 朱俊豪

    2015-01-01

    With the comprehensive comparison of integrally geared centrifugal compressor and single shaft multistage compressor, including layout of machine set, type of driver, out contour size and space needed in workshop, and investment cost, for the feed alr tubo-compressor set and booster alr tubo-compressor set used in the large alr separation plant, it is determined that integrally geared centrifugal compressor should be selected in priority.%通过对多轴齿轮式多级离心式压缩机组和单轴多级离心式压缩机组的压缩机组型式、驱动机型式、外形尺寸和厂房空间需求、投资费用等方面的综合技术选评比较可知,本次4.2万系列空分项目所选用的原料空压机组和增压机组,应优先选用多轴齿轮式多级离心压缩机组。

  1. Enrichment: centrifuge process

    International Nuclear Information System (INIS)

    This short course is divided into three sections devoted respectively to the physics of the process, some practical problems raised by the design of a centrifuge and the present situation of centrifugation in the World. 31 figs., 18 refs

  2. Detection of outliers by neural network on the gas centrifuge experimental data of isotopic separation process; Aplicacao de redes neurais para deteccao de erros grosseiros em dados de processo de separacao de isotopos de uranio por ultracentrifugacao

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Monica de Carvalho Vasconcelos

    2004-07-01

    This work presents and discusses the neural network technique aiming at the detection of outliers on a set of gas centrifuge isotope separation experimental data. In order to evaluate the application of this new technique, the result obtained of the detection is compared to the result of the statistical analysis combined with the cluster analysis. This method for the detection of outliers presents a considerable potential in the field of data analysis and it is at the same time easier and faster to use and requests very less knowledge of the physics involved in the process. This work established a procedure for detecting experiments which are suspect to contain gross errors inside a data set where the usual techniques for identification of these errors cannot be applied or its use/demands an excessively long work. (author)

  3. Gas dynamics in strong centrifugal fields

    Energy Technology Data Exchange (ETDEWEB)

    Bogovalov, S.V.; Kislov, V.A.; Tronin, I.V. [National research nuclear university “MEPhI”, Kashirskoje shosse, 31,115409, Moscow (Russian Federation)

    2015-03-10

    Dynamics of waves generated by scopes in gas centrifuges (GC) for isotope separation is considered. The centrifugal acceleration in the GC reaches values of the order of 106g. The centrifugal and Coriolis forces modify essentially the conventional sound waves. Three families of the waves with different polarisation and dispersion exist in these conditions. Dynamics of the flow in the model GC Iguasu is investigated numerically. Comparison of the results of the numerical modelling of the wave dynamics with the analytical predictions is performed. New phenomena of the resonances in the GC is found. The resonances occur for the waves polarized along the rotational axis having the smallest dumping due to the viscosity.

  4. Centrifuge modeling of monopiles

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte

    2010-01-01

    To gain a larger knowledge of the monopile foundation concept, centrifuge modeling is used by the geotechnical group at DTU. The centrifuge operated at DTU is a beam centrifuge and was built in 1976. In the recent years it has been upgraded with onboard data acquisition and control systems....... The capabilities of the centrifuge at DTU makes it possible to obtain a scale factor of 85 in experiments which equals a soil volume in prototype scale of a diameter of 40 meters and a depth of 40 meters. This paper describes centrifuge modeling theory, the centrifuge setup at DTU and as an example show results...... from centrifuge tests performed on large diameter piles installed in dry sand....

  5. CFD Simulation of Annular Centrifugal Extractors

    OpenAIRE

    Vedantam, S.; Wardle, K. E.; Tamhane, T. V.; Ranade, V. V.; Joshi, J. B.

    2012-01-01

    Annular centrifugal extractors (ACE), also called annular centrifugal contactors offer several advantages over the other conventional process equipment such as low hold-up, high process throughput, low residence time, low solvent inventory and high turn down ratio. The equipment provides a very high value of mass transfer coefficient and interfacial area in the annular zone because of the high level of power consumption per unit volume and separation inside the rotor due to the high g of cent...

  6. Human peripheral blood monocyte separation with Nycodenz-NaCl density osmotic pressure medium centrifugation%Nycodenz-密度渗透压介质离心分离人外周血单核细胞研究

    Institute of Scientific and Technical Information of China (English)

    尹建平; 余谨; 王先广; 陈禹潭; 马威; 赵云斌

    2011-01-01

    Anticloagulated whole blood or mononuclear cell suspensions wereare slowly added to the upper layer of Nycodenz-NaCl solutions of various density and osmotic pressure combinations, and centrifuged to separate monocytes. AfterFollowing the mononuclear cell suspensions were obtained by Ficoll-Hypaque density gradient centrifugation from EDTA whole blood, monocytes wereare respectively separated with different methods such aa Nycodenz-NaCl density osmotic pressure medium centrifugation, Percoll density gradient centrifugation, adherence method, Magnetic beads-activated cell sorting (MACS). Results The purities and yields of monocytes obtained by the above four methods arewere respectively 98.9% ( median ), ranged ( 96% ~ 100%, range ), and and 68.5% ( ranged 54% ~ 83 % ), 89.6% ( ranged 84% ~ 92% ) and 64.5% (51% ~78% ) ,64.8% (ranged 55% ~76% ) and 60.5% (ranged 47% ~72% ) ,94. 1% (ranged 91% ~98% ) and 73. 5% ( ranged 59% ~ 88% ) respectively, for Nycodenz-NaCl density osmotic pressure medium centrifugation, Percoll density gradient centrifugation, adherence method, and Magnetic beads-activated cell sorting (MACS). The purity of monocytes separated with Nycodenz-NaCl iwas the highest among these methods. ( P < 0.01 ). The phagocytosis indexes and chemotactic indexes of monocytes wereare respectively 188.8 ±11.2 and 26.8 ±5.9、187.8 ±12.2 and 26. 1 ±5.1、144.4 ±24.8 and 15.4 ± 7.3、177.1±18.3 and 18.9 ± 6.7 respectively. , The phagocytosis indexes and chemotactic indexes of monocytes separated with Percoll and Nycodenz-NaCl wereare significantly higher than with adherence and MACS. (P < 0.05). Secreting cytokines IL-12p70, IL-10, TNF alpha levels of LPS stimulating monocytes obtained by the above methods are (2 545 ±341,1 216 ±397,3.999 ±418),(2 489 ±425,1 080 ±277,3 891 ±446),(2 147 ±223,794 ±180,3 268 ±411) ,(35 ± 12、142 ±81、407 ± 199) ,respectively. Secreting cytokines IL-12p70, IL-10,TNF

  7. Experimental study of stable isotope separation

    International Nuclear Information System (INIS)

    This paper presents some results of investigation into a gas centrifuge and gas centrifuge cascade. The chemical compounds of osmium - OsO4, tungsten - WF6 and xenon were chosen for centrifugal separation, and the centrifugal technology for the separation of osmium, tungsten and xenon were developed. The separation factors for molar mass differences, γ0, were obtained for OsO4, Xe, WF6 in a single gas centrifuge. The separation by gas centrifuge cascade has been done and some results of the investigation are shown. High abundance of 186W (>90 %), 129Xe (>65 %) and 192 Os (>99 %) was produced using the short cascade

  8. Hyperbolically Shaped Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Romuald Puzyrewski; Pawel Flaszy(n)ski

    2003-01-01

    Starting from the classical centrifugal compressor, cone shaped in meridional cross section, two modifications are considered on the basis of results from 2D and 3D flow models. The first modification is the change of the meridional cross section to hyperbolically shaped channel. The second modification, proposed on the basis of 2D axisymmetric solution, concerns the shape of blading. On the strength of this solution the blades are formed as 3D shaped blades, coinciding with the recent tendency in 3D designs. Two aims were considered for the change of meridional compressor shape. The first was to remove the separation zone which appears as the flow tums from axial to radial direction. The second aim is to uniformize the flow at exit of impeller. These two goals were considered within the frame of 2D axisymmetric model. Replacing the cone shaped compressor by a hyperbolically shaped one, the separation at the corner was removed. The disc and shroud shape of the compressor was chosen in the way which satisfies the condition of most uniform flow at the compressor exit. The uniformity of exit flow from the rotor can be considered as the factor which influences the performance of the diffuser following the rotor. In the 2D model a family of stream surfaces of S1 type is given in order to find S2 surfaces which may be identified with the midblade surfaces of compressor blading. A computation of 3D type has been performed in order to establish the relations between 2D and 3D models in the calculation of flow parameters. In the presented example the 2D model appears as the inverse model which leads to 3D shape of blading whereas the 3D model has been used for the direct solution. In the presented example the confrontation of two models, 2D and 3D, leads to a better understanding of the application of these models to the design procedure.

  9. Centrifugal pump handbook

    CERN Document Server

    Pumps, Sulzer

    2010-01-01

    This long-awaited new edition is the complete reference for engineers and designers working on pump design and development or using centrifugal pumps in the field. This authoritative guide has been developed with access to the technical expertise of the leading centrifugal pump developer, Sulzer Pumps. In addition to providing the most comprehensive centrifugal pump theory and design reference with detailed material on cavitation, erosion, selection of materials, rotor vibration behavior and forces acting on pumps, the handbook also covers key pumping applications topics and operational

  10. DESIGN INFORMATION REPORT: CENTRIFUGES

    Science.gov (United States)

    In the 1960s, manufacturers began to design centrifuges specifically for wastewater sludge applications. In addition, sludge thickening and dewatering processes were improved with the introduction of polyelectrolytes for chemical sludge conditioning. The report contains a brief d...

  11. 21 CFR 864.9275 - Blood bank centrifuge for in vitro diagnostic use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood bank centrifuge for in vitro diagnostic use... Manufacture Blood and Blood Products § 864.9275 Blood bank centrifuge for in vitro diagnostic use. (a) Identification. A blood bank centrifuge for in vitro diagnostic use is a device used only to separate blood...

  12. Detection methods for centrifugal microfluidic platforms.

    Science.gov (United States)

    Burger, Robert; Amato, Letizia; Boisen, Anja

    2016-02-15

    Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation, have been developed and allow automation and integration of complex assay protocols in lab-on-a-disc systems. Besides liquid handling, the detection strategy for reading out the assay is crucial for developing a fully integrated system. In this review, we focus on biosensors and readout methods for the centrifugal microfluidics platform and cover optical as well as mechanical and electrical detection principles.

  13. Analysis of Secondary Flows in Centrifugal Impellers

    Directory of Open Access Journals (Sweden)

    Brun Klaus

    2005-01-01

    Full Text Available Secondary flows are undesirable in centrifugal compressors as they are a direct cause for flow (head losses, create nonuniform meridional flow profiles, potentially induce flow separation/stall, and contribute to impeller flow slip; that is, secondary flows negatively affect the compressor performance. A model based on the vorticity equation for a rotating system was developed to determine the streamwise vorticity from the normal and binormal vorticity components (which are known from the meridional flow profile. Using the streamwise vorticity results and the small shear-large disturbance flow method, the onset, direction, and magnitude of circulatory secondary flows in a shrouded centrifugal impeller can be predicted. This model is also used to estimate head losses due to secondary flows in a centrifugal flow impeller. The described method can be employed early in the design process to develop impeller flow shapes that intrinsically reduce secondary flows rather than using disruptive elements such as splitter vanes to accomplish this task.

  14. A Review of Biomedical Centrifugal Microfluidic Platforms

    Directory of Open Access Journals (Sweden)

    Minghui Tang

    2016-02-01

    Full Text Available Centrifugal microfluidic or lab-on-a-disc platforms have many advantages over other microfluidic systems. These advantages include a minimal amount of instrumentation, the efficient removal of any disturbing bubbles or residual volumes, and inherently available density-based sample transportation and separation. Centrifugal microfluidic devices applied to biomedical analysis and point-of-care diagnostics have been extensively promoted recently. This paper presents an up-to-date overview of these devices. The development of biomedical centrifugal microfluidic platforms essentially covers two categories: (i unit operations that perform specific functionalities, and (ii systems that aim to address certain biomedical applications. With the aim to provide a comprehensive representation of current development in this field, this review summarizes progress in both categories. The advanced unit operations implemented for biological processing include mixing, valving, switching, metering and sequential loading. Depending on the type of sample to be used in the system, biomedical applications are classified into four groups: nucleic acid analysis, blood analysis, immunoassays, and other biomedical applications. Our overview of advanced unit operations also includes the basic concepts and mechanisms involved in centrifugal microfluidics, while on the other hand an outline on reported applications clarifies how an assembly of unit operations enables efficient implementation of various types of complex assays. Lastly, challenges and potential for future development of biomedical centrifugal microfluidic devices are discussed.

  15. Geotechnical centrifuge under construction

    Science.gov (United States)

    Richman, Barbara T.

    Modifications are underway at the National Aeronautics and Space Administration (NASA) Ames Research Center in California to transform a centrifuge used in the Apollo space program to the largest geotechnical centrifuge in the free world. The centrifuge, to be finished in August and opened next January, following check out and tuning, will enable geoscientists to model stratigraphic features down to 275 m below the earth's surface. Scientists will be able to model processes that are coupled with body force loading, including earthquake response of earth structures and soil structure interaction; rubbled-bed behavior during in situ coal gasification or in oil shale in situ retorts; behavior of frozen soil; frost heave; behavior of offshore structures; wave-seabed interactions; explosive cratering; and blast-induced liquefaction.The centrifuge will have a load capacity of 900-g-tons (short); that is, it will be able to carry a net soil load of 3 short tons to a centripetal acceleration of 300 times the acceleration caused by gravity. Modified for a total cost of $2.4 million, the centrifuge will have an arm with a 7.6-m radius and a swinging platform or bucket at its end that will be able to carry a payload container measuring 2.1×2.1 m. An additional future input of $500,000 would enable the purchase of a larger bucket that could accommodate a load of up to 20 tons, according to Charles Babendreier, program director for geotechnical engineering at the National Science Foundation. Additional cooling for the motor would also be required. The centrifuge has the capability of accelerating the 20-ton load to 100 g.

  16. Perceived radial translation during centrifugation

    NARCIS (Netherlands)

    Bos, J.E.; Correia Grácio, B.J.

    2015-01-01

    BACKGROUND: Linear acceleration generally gives rise to translation perception. Centripetal acceleration during centrifugation, however, has never been reported giving rise to a radial, inward translation perception. OBJECTIVE: To study whether centrifugation can induce a radial translation percepti

  17. Central centrifugal cicatricial alopecia

    OpenAIRE

    Collin Blattner; Dennis C Polley; Frank Ferritto; Elston, Dirk M

    2013-01-01

    Central centrifugal cicatricial alopecia is a common cause of progressive permanent apical alopecia. This unique form of alopecia includes entities previously know as “hot comb alopecia,” “follicular degeneration syndrome,” “pseudopelade” in African Americans and “central elliptical pseudopelade” in Caucasians. The etiology appears to be multifactorial and the condition occurs in all races.

  18. Centrifugal atomisation of alloys

    Energy Technology Data Exchange (ETDEWEB)

    Li Huiping [School of Mechanical and Materials Engineering, Univ. of Surrey, Guilford (United Kingdom); Dept. of Inorganic Materials, East China Univ. of Science and Technology, Shanghai, SH (China); Tsakiropoulos, P. [School of Mechanical and Materials Engineering, Univ. of Surrey, Guilford (United Kingdom); Johnson, T. [Tetronics Ltd., Faringdon, Oxfordshire (United Kingdom)

    2001-07-01

    Centrifugal atomisation using a rotating disk is described and compared to REP and PREP. Results of calculations of models describing the interaction of a melt with a rotating disk, the formation of thin film on the disk and the break up of the thin film and its atomisation at the edge of the disk are compared with experimental results. (orig.)

  19. Centrifugal analyzer development

    International Nuclear Information System (INIS)

    The development of the centrifuge fast analyzer (CFA) is reviewed. The development of a miniature CFA with computer data analysis is reported and applications for automated diagnostic chemical and hematological assays are discussed. A portable CFA system with microprocessor was adapted for field assays of air and water samples for environmental pollutants, including ammonia, nitrates, nitrites, phosphates, sulfates, and silica. 83 references

  20. Topological analysis of the formation of Jet-Wake flow pattern in centrifugal impeller channel

    Institute of Scientific and Technical Information of China (English)

    ZHENG Qun; LIU Shun-long

    2004-01-01

    Topological analyses are carried out for the numerical results of internal flow field in centrifugal impeller. Topological rules of the singular point characteristics of the limiting streamline are derived and used to determine three dimensional separation patterns in centrifugal impeller and to verify the numerical results. The results reveal that the wake is saddle to nodal closed separation and the formation, its onset point and its developing process of Jet-Wake Flow pattern in centrifugal impeller are presented in this paper.

  1. Centrifugal membrane filtration - Task 9

    International Nuclear Information System (INIS)

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-microm TiO2/Al2O3 membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance

  2. Centrifugal membrane filtration -- Task 9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., the developer of a centrifugal membrane filtration technology, to demonstrate applications for the SpinTek technology within the US Department of Energy (DOE) Environmental management (EM) Program. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. This is a crosscutting technology that falls under the Efficient Separations and Processing Crosscutting Program, with potential application to tank wastes, contaminated groundwater, landfill leachate, and secondary liquid waste streams from other remediation processes, including decontamination and decommissioning systems. Membrane-screening tests were performed with the SpinTek STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{micro}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the SpinTek ST-IIL centrifugal membrane filtration unit with a surrogate tank waste solution. An extended test run of 100 hr performed on a surrogate tank waste solution showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  3. Centripetal/Centrifugal Family Style of Families with Aggressive and Non-Aggressive Boys.

    Science.gov (United States)

    Hurst, Duane F.; And Others

    Research on family interaction has characterized family style on centripetal and centrifugal dimensions, representing opposing natures with their own continua. Centripetal forces produce binding, or a prolonged process of separation of parent and child; centrifugal forces preciptate expelling, or hastened separation and premature autonomy. To…

  4. CFD Simulation of Annular Centrifugal Extractors

    Directory of Open Access Journals (Sweden)

    S. Vedantam

    2012-01-01

    Full Text Available Annular centrifugal extractors (ACE, also called annular centrifugal contactors offer several advantages over the other conventional process equipment such as low hold-up, high process throughput, low residence time, low solvent inventory and high turn down ratio. The equipment provides a very high value of mass transfer coefficient and interfacial area in the annular zone because of the high level of power consumption per unit volume and separation inside the rotor due to the high g of centrifugal field. For the development of rational and reliable design procedures, it is important to understand the flow patterns in the mixer and settler zones. Computational Fluid Dynamics (CFD has played a major role in the constant evolution and improvements of this device. During the past thirty years, a large number of investigators have undertaken CFD simulations. All these publications have been carefully and critically analyzed and a coherent picture of the present status has been presented in this review paper. Initially, review of the single phase studies in the annular region has been presented, followed by the separator region. In continuation, the two-phase CFD simulations involving liquid-liquid and gas-liquid flow in the annular as well as separator regions have been reviewed. Suggestions have been made for the future work for bridging the existing knowledge gaps. In particular, emphasis has been given to the application of CFD simulations for the design of this equipment.

  5. Differential white cell count by centrifugal microfluidics.

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Gregory Jon; Tentori, Augusto M.; Schaff, Ulrich Y.

    2010-07-01

    We present a method for counting white blood cells that is uniquely compatible with centrifugation based microfluidics. Blood is deposited on top of one or more layers of density media within a microfluidic disk. Spinning the disk causes the cell populations within whole blood to settle through the media, reaching an equilibrium based on the density of each cell type. Separation and fluorescence measurement of cell types stained with a DNA dye is demonstrated using this technique. The integrated signal from bands of fluorescent microspheres is shown to be proportional to their initial concentration in suspension. Among the current generation of medical diagnostics are devices based on the principle of centrifuging a CD sized disk functionalized with microfluidics. These portable 'lab on a disk' devices are capable of conducting multiple assays directly from a blood sample, embodied by platforms developed by Gyros, Samsung, and Abaxis. [1,2] However, no centrifugal platform to date includes a differential white blood cell count, which is an important metric complimentary to diagnostic assays. Measuring the differential white blood cell count (the relative fraction of granulocytes, lymphocytes, and monocytes) is a standard medical diagnostic technique useful for identifying sepsis, leukemia, AIDS, radiation exposure, and a host of other conditions that affect the immune system. Several methods exist for measuring the relative white blood cell count including flow cytometry, electrical impedance, and visual identification from a stained drop of blood under a microscope. However, none of these methods is easily incorporated into a centrifugal microfluidic diagnostic platform.

  6. Centrifugal unbalance detection system

    Science.gov (United States)

    Cordaro, Joseph V.; Reeves, George; Mets, Michael

    2002-01-01

    A system consisting of an accelerometer sensor attached to a centrifuge enclosure for sensing vibrations and outputting a signal in the form of a sine wave with an amplitude and frequency that is passed through a pre-amp to convert it to a voltage signal, a low pass filter for removing extraneous noise, an A/D converter and a processor and algorithm for operating on the signal, whereby the algorithm interprets the amplitude and frequency associated with the signal and once an amplitude threshold has been exceeded the algorithm begins to count cycles during a predetermined time period and if a given number of complete cycles exceeds the frequency threshold during the predetermined time period, the system shuts down the centrifuge.

  7. Centrifugally decoupling touchdown bearings

    Science.gov (United States)

    Post, Richard F

    2014-06-24

    Centrifugally decoupling mechanical bearing systems provide thin tensioned metallic ribbons contained in a support structure. This assembly rotates around a stationary shaft being centered at low speeds by the action of the metal ribbons. Tension springs are connected on one end to the ribbons and on the other end to the support structure. The ribbons pass through slots in the inner ring of the support structure. The spring preloading thus insures contact (or near-contact) between the ribbons and the shaft at rotation speeds below the transition speed. Above this speed, however, the centrifugal force on the ribbons produces a tensile force on them that exceeds the spring tensile force so that the ribbons curve outward, effectively decoupling them from mechanical contact with the shaft. They still remain, however, in position to act as a touchdown bearing in case of abnormally high transverse accelerations.

  8. Performance in Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    K. Sato

    1999-01-01

    Full Text Available A 3-D unsteady thin-layer Navier-Stokes code has been used to calculate the flow through a centrifugal compressor stage. The validation of the code for steady flows in centrifugal compressors was conducted for the Krain’s impeller with a vaneless diffuser as a test case and the numerical results were compared with the experimental results. The predicted flow field and performance agreed well with the experimental data. An unsteady stage solution was then conducted with this impeller followed by a generic low-solidity vaned-diffuser to examine the unsteady effects on the impeller performance. The computational results showed a stabilising effect of the blade row interaction.

  9. Gas Centrifuges and Nuclear Proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Albright, David

    2004-09-15

    Gas centrifuges have been an ideal enrichment method for a wide variety of countries. Many countries have built gas centrifuges to make enriched uranium for peaceful nuclear purposes. Other countries have secretly sought centrifuges to make highly enriched uranium for nuclear weapons. In more recent times, several countries have secretly sought or built gas centrifuges in regions of tension. The main countries that have been of interest in the last two decades have been Pakistan, Iraq, Iran, and North Korea. Currently, most attention is focused on Iran, Pakistan, and North Korea. These states did not have the indigenous abilities to make gas centrifuges, focusing instead on illicit and questionable foreign procurement. The presentation covered the following main sections: Spread of centrifuges through illicit procurement; Role of export controls in stopping proliferation; Increasing the transparency of gas centrifuge programs in non-nuclear weapon states; and, Verified dismantlement of gas centrifuge programs. Gas centrifuges are important providers of low enriched uranium for civil nuclear power reactors. They also pose special nuclear proliferation risks. We all have special responsibilities to prevent the spread of gas centrifuges into regions of tension and to mitigate the consequences of their spread into the Middle East, South Asia, and North Asia.

  10. Centrifugal-reciprocating compressor

    Science.gov (United States)

    Higa, W. H. (Inventor)

    1984-01-01

    A centrifugal compressor is described which includes at least one pair of cylinders arranged in coaxial alignment and supported for angular displacement about a common axis of rotation normally disecting a common longitudinal axis of symmetry for the cylinders. The cylinders are characterized by ported closures located at the mutually remote ends thereof through which the cylinders are charged and discharged, and a pair of piston heads seated within the cylinders and supported for floating displacement in compressive strokes in response to unidirectional angular displacement imparted to the cylinders.

  11. Centrifugal bucket hoist

    OpenAIRE

    Kotačka, Petr

    2014-01-01

    This bachelor thesis deals with an engineering design of a centrifugal bucket elevator with transport height 6.5 metres and transport performance 40 000 kilograms per hour. The thesis focuses especially on a functional calculation of the elevator thanks to which a gear motor, band and bucket are chosen. This is followed by an analysis of a constructional solution with a strength check of a drive shaft and parallel keys as well as a calculation of a service life of bearings. Technical document...

  12. Centrifugal shot blast system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This report describes a demonstration of Concrete cleaning, Inc., modified centrifugal shot blast technology to remove the paint coating from concrete flooring. This demonstration is part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), office of Science and Technology (OST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) CP-5 Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved decontamination and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. Potential markets exist for the innovative centrifugal shot blast system at the following sites: Fernald Environmental Management Project, Los Alamos, Nevada, Oak Ridge Y-12 and K-25, Paducah, Portsmouth Gaseous Diffusion site, and the Savannah River Site. This information is based on a revision to the OST Linkage Tables dated August 4, 1997.

  13. Centrifugal shot blast system

    International Nuclear Information System (INIS)

    This report describes a demonstration of Concrete cleaning, Inc., modified centrifugal shot blast technology to remove the paint coating from concrete flooring. This demonstration is part of the Chicago Pile-5 (CP-5) Large-Scale Demonstration Project (LSDP) sponsored by the US Department of Energy (DOE), office of Science and Technology (OST), Deactivation and Decommissioning Focus Area (DDFA). The objective of the LSDP is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) CP-5 Research Reactor. The purpose of the LSDP is to demonstrate that using innovative and improved decontamination and decommissioning (D and D) technologies from various sources can result in significant benefits, such as decreased cost and increased health and safety, as compared with baseline D and D technologies. Potential markets exist for the innovative centrifugal shot blast system at the following sites: Fernald Environmental Management Project, Los Alamos, Nevada, Oak Ridge Y-12 and K-25, Paducah, Portsmouth Gaseous Diffusion site, and the Savannah River Site. This information is based on a revision to the OST Linkage Tables dated August 4, 1997

  14. Deep eutectic solvents in countercurrent and centrifugal partition chromatography.

    Science.gov (United States)

    Roehrer, Simon; Bezold, Franziska; García, Eva Marra; Minceva, Mirjana

    2016-02-19

    Deep eutectic solvents (DESs) were evaluated as solvents in centrifugal partition chromatography, a liquid-liquid chromatography separation technology. To this end, the partition coefficients of ten natural compounds of different hydrophobicity were determined in non-aqueous biphasic systems containing DES. The influence of the composition of DESs and the presence of water in the biphasic system on the partition coefficient were also examined. In addition, several process relevant physical properties of the biphasic system, such as the density and viscosity of the phases, were measured. A mixture of three to four hydrophobic compounds was successfully separated in a centrifugal partition extractor using a heptane/ethanol/DES biphasic system.

  15. Deep eutectic solvents in countercurrent and centrifugal partition chromatography.

    Science.gov (United States)

    Roehrer, Simon; Bezold, Franziska; García, Eva Marra; Minceva, Mirjana

    2016-02-19

    Deep eutectic solvents (DESs) were evaluated as solvents in centrifugal partition chromatography, a liquid-liquid chromatography separation technology. To this end, the partition coefficients of ten natural compounds of different hydrophobicity were determined in non-aqueous biphasic systems containing DES. The influence of the composition of DESs and the presence of water in the biphasic system on the partition coefficient were also examined. In addition, several process relevant physical properties of the biphasic system, such as the density and viscosity of the phases, were measured. A mixture of three to four hydrophobic compounds was successfully separated in a centrifugal partition extractor using a heptane/ethanol/DES biphasic system. PMID:26810802

  16. Centrifugal microfluidics for biomedical applications.

    Science.gov (United States)

    Gorkin, Robert; Park, Jiwoon; Siegrist, Jonathan; Amasia, Mary; Lee, Beom Seok; Park, Jong-Myeon; Kim, Jintae; Kim, Hanshin; Madou, Marc; Cho, Yoon-Kyoung

    2010-07-21

    The centrifugal microfluidic platform has been a focus of academic and industrial research efforts for almost 40 years. Primarily targeting biomedical applications, a range of assays have been adapted on the system; however, the platform has found limited commercial success as a research or clinical tool. Nonetheless, new developments in centrifugal microfluidic technologies have the potential to establish wide-spread utilization of the platform. This paper presents an in-depth review of the centrifugal microfluidic platform, while highlighting recent progress in the field and outlining the potential for future applications. An overview of centrifugal microfluidic technologies is presented, including descriptions of advantages of the platform as a microfluidic handling system and the principles behind centrifugal fluidic manipulation. The paper also discusses a history of significant centrifugal microfluidic platform developments with an explanation of the evolution of the platform as it pertains to academia and industry. Lastly, we review the few centrifugal microfluidic-based sample-to-answer analysis systems shown to date and examine the challenges to be tackled before the centrifugal platform can be more broadly accepted as a new diagnostic platform. In particular, fully integrated, easy to operate, inexpensive and accurate microfluidic tools in the area of in vitro nucleic acid diagnostics are discussed.

  17. Unshrouded Centrifugal Turbopump Impeller

    Science.gov (United States)

    Prueger, George; Williams, Morgan; Chen, Wei; Paris, John; Stewart, Eric; Williams, Robert

    1999-01-01

    The ratio of rocket engine thrust to weight is a limiting constraint in placing more payload into orbit at a low cost. A key component of an engine's overall weight is the turbopump weight, Reducing the turbopump weight can result in significant engine weight reduction and hence, increased delivered payload. There are two main types of pumps: centrifugal and axial pumps. These types of pumps can be further sub-divided into those with shrouds and those without shrouds (unshrouded pumps). Centrifugal pumps can achieve the same pump discharge pressure as an axial pump and it requires fewer pump stages and lower pump weight than an axial pump. Also, with unshrouded centrifugal pumps (impeller), the number of stages and weight can be further reduced. However. there are several issues with regard to using an unshrouded impeller: 1) there is a pump performance penalty due to the front open face recirculation flow; 2) there is a potential pump axial thrust problem from the unbalanced front open face and the back shroud face; and, 3) since test data is very linu'ted for this configuration, there is uncertainty in the magnitude and phase of the rotordynamics forces due to the front impeller passage. The purpose of the paper is to discuss the design of an unshrouded impeller and to examine the design's hydrodynamic performance, axial thrust, and rotordynamics performance. The design methodology will also be discussed. This work will help provide some guidelines for unshrouded impeller design. In particular, the paper will discuss the design of three unshrouded impellers - one with 5 full and 5 partial blades (5+5). one with 6+6 blades and one with 8+8 blades. One of these designs will be selected for actual fabrication and flow test. Computational fluid dynamics (CFD) is used to help design and optimize the unshrouded impeller. The relative pump performance penalty is assessed by comparing the CFD results of the unshrouded impeller with the equivalent shrouded impeller for a

  18. [Galileo and centrifugal force].

    Science.gov (United States)

    Vilain, Christiane

    This work intends to focus on Galileo's study of what is now called "centrifugal force," within the framework of the Second Day of his Dialogo written in 1632, rather than on the previously published commentaries on the topic. Galileo proposes three geometrical demonstrations in order to prove that gravity will always overcome centrifugalforce, and that the potential rotation of the Earth, whatever its speed, cannot in any case project objects beyond it. Each of these demonstrations must consequently contain an error and it has seemed to us that the first one had not been understood up until now. Our analysis offers an opportunity to return to Galileo's geometrical representation of dynamical questions; actually, we get an insight into the sophistication of Galileo's practices more than into his mistakes. Our second point, concerning the historiography of the problem, shows an evolution from anachronic critics to more contextual considerations, in the course of the second half of the twentieth century.

  19. [Galileo and centrifugal force].

    Science.gov (United States)

    Vilain, Christiane

    This work intends to focus on Galileo's study of what is now called "centrifugal force," within the framework of the Second Day of his Dialogo written in 1632, rather than on the previously published commentaries on the topic. Galileo proposes three geometrical demonstrations in order to prove that gravity will always overcome centrifugalforce, and that the potential rotation of the Earth, whatever its speed, cannot in any case project objects beyond it. Each of these demonstrations must consequently contain an error and it has seemed to us that the first one had not been understood up until now. Our analysis offers an opportunity to return to Galileo's geometrical representation of dynamical questions; actually, we get an insight into the sophistication of Galileo's practices more than into his mistakes. Our second point, concerning the historiography of the problem, shows an evolution from anachronic critics to more contextual considerations, in the course of the second half of the twentieth century. PMID:25029818

  20. Stable isotope enrichment using a plasma centrifuge

    Science.gov (United States)

    Krishnan, Mahadevan; Bures, Brian; Madden, Robert

    2012-10-01

    A primary goal of the Department of Energy's Isotope Development and Production for Research and Applications Program (Isotope Program) within the Office of Nuclear Physics (NP) is to produce isotopes that are in short supply in the U.S. and of which there exists no or insufficient domestic commercial production capability. A vacuum arc plasma centrifuge is a rigid rotor column of metal plasma in which centrifugal forces re-distribute ions radially according to their mass/charge ratio. Early work demonstrated rotation at 2 million rpm and separation of various stable isotopes. The spinning plasma column had a Gaussian flux profile, peaked on the rigid rotor axis. This work adopts a more efficient approach, with the plasma created as a hollow column, wherein the flux is concentrated at larger radii where the centrifugal action is highest. By tailoring the vacuum arc discharge geometry, the rotation rate can also be increased to ˜10 million rpm. Data from Cu, Al and other metal plasmas will be presented and discussed in light of enriched stable isotopes needed for research and medicine.

  1. EM Task 9 - Centrifugal Membrane Filtration

    International Nuclear Information System (INIS)

    This project is designed to establish the utility of a novel centrifugal membrane filtration technology for the remediation of liquid mixed waste streams at US Department of Energy (DOE) facilities in support of the DOE Environmental Management (EM) program. The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., a small business and owner of the novel centrifugal membrane filtration technology, to establish the applicability of the technology to DOE site remediation and the commercial viability of the technology for liquid mixed waste stream remediation. The technology is a uniquely configured process that makes use of ultrafiltration and centrifugal force to separate suspended and dissolved solids from liquid waste streams, producing a filtered water stream and a low-volume contaminated concentrate stream. This technology has the potential for effective and efficient waste volume minimization, the treatment of liquid tank wastes, the remediation of contaminated groundwater plumes, and the treatment of secondary liquid waste streams from other remediation processes, as well as the liquid waste stream generated during decontamination and decommissioning activities

  2. Centrifugal microfluidic platforms: advanced unit operations and applications.

    Science.gov (United States)

    Strohmeier, O; Keller, M; Schwemmer, F; Zehnle, S; Mark, D; von Stetten, F; Zengerle, R; Paust, N

    2015-10-01

    Centrifugal microfluidics has evolved into a mature technology. Several major diagnostic companies either have products on the market or are currently evaluating centrifugal microfluidics for product development. The fields of application are widespread and include clinical chemistry, immunodiagnostics and protein analysis, cell handling, molecular diagnostics, as well as food, water, and soil analysis. Nevertheless, new fluidic functions and applications that expand the possibilities of centrifugal microfluidics are being introduced at a high pace. In this review, we first present an up-to-date comprehensive overview of centrifugal microfluidic unit operations. Then, we introduce the term "process chain" to review how these unit operations can be combined for the automation of laboratory workflows. Such aggregation of basic functionalities enables efficient fluidic design at a higher level of integration. Furthermore, we analyze how novel, ground-breaking unit operations may foster the integration of more complex applications. Among these are the storage of pneumatic energy to realize complex switching sequences or to pump liquids radially inward, as well as the complete pre-storage and release of reagents. In this context, centrifugal microfluidics provides major advantages over other microfluidic actuation principles: the pulse-free inertial liquid propulsion provided by centrifugal microfluidics allows for closed fluidic systems that are free of any interfaces to external pumps. Processed volumes are easily scalable from nanoliters to milliliters. Volume forces can be adjusted by rotation and thus, even for very small volumes, surface forces may easily be overcome in the centrifugal gravity field which enables the efficient separation of nanoliter volumes from channels, chambers or sensor matrixes as well as the removal of any disturbing bubbles. In summary, centrifugal microfluidics takes advantage of a comprehensive set of fluidic unit operations such as

  3. Gas centrifuge bibliography 1980-1982

    International Nuclear Information System (INIS)

    A bibliography, with abstract, is presented of the gas centrifuge literature published from 1980 to 1982 inclusive. It supplements PG Information Series 25 (CA), BNFL Information Series 15 (CA) and BNFL Information Series 23 (CA), which covered the periods 1895 to 1970, 1970 to 1974, and 1975 to 1979 respectively. After bibliographies and books and pamphlets, the main list is arranged chronologically under the headings, Reports, Journal articles, and Conference papers. Items omitted from the earlier bibliographies or received too late for inclusion in this, have been listed separately. There are author, report number and subject indexes. (U.K.)

  4. Rotordynamic Forces on Centrifugal Pump Impellers

    OpenAIRE

    Franz, R.; Arndt, N.; Caughey, T. K.; Brennen, C. E.; Acosta, A.J

    1987-01-01

    The asymmetric flow around an impeller in a volute exerts a force upon the impeller. To study the rotordynamic force on an impeller which is vibrating around its machine axis of rotation, the impeller, mounted on a dynamometer, is made to whirl in a circular orbit within the volute. The measured force is expressed as the sum of a steady radial force and an unsteady force due to the eccentric motion of the impeller. These forces were measured in separate tests on a centrifugal pump with rad...

  5. Spiral Flow Separator

    Science.gov (United States)

    Robertson, Glen A.

    1993-01-01

    Proposed liquid-separating device relies on centrifugal force in liquid/liquid or liquid/solid mixture in spiral path. Operates in continuous flow at relatively high rates. Spiral tubes joined in sequence, with outlet tubes connected to joints. Cross-sectional areas of successive spiral tubes decreases by cross-sectional areas of outlet tubes. Centrifugal force pushes denser particles or liquids to outer edge of spiral, where removed from flow. Principle exploited to separate solids from wastewater, oil from fresh or salt water, or contaminants from salt water before evaporation. Also used to extract such valuable materials as precious metals from slurries.

  6. Uranium enrichment by gas centrifuge

    International Nuclear Information System (INIS)

    After recalling the physical principles and the techniques of centrifuge enrichment the report describes the centrifuge enrichment programmes of the various countries concerned and compares this technology with other enrichment technologies like gaseous diffusion, laser, aerodynamic devices and chemical processes. The centrifuge enrichment process is said to be able to replace with advantage the existing enrichment facilities in the short and medium term. Future prospects of the process are also described, like recycled uranium enrichment and economic improvements; research and development needs to achieve the economic prospects are also indicated. Finally the report takes note of the positive aspect of centrifuge enrichment as far as safeguards and nuclear safety are concerned. 27 figs, 113 refs

  7. The recovery of biological particles in high-speed continuous centrifuges with special reference to feed-zone break-up effects

    OpenAIRE

    Mannweiler, K.

    1989-01-01

    In the first part of this thesis the means are described by which an industrial disc stack centrifuge may be scaled-down to process in a meaningful fashion small volumes of particle suspensions. The centrifuge separation characteristics so measured were suitable for direct scale-up predictions of centrifuge performance. Experiments with a dye tracer and a reduced number of discs indicated that the flow through the disc centrifuge is influenced by the position of the separati...

  8. [The analytical setting of rotary speed of centrifuge rotor and centrifugation time in chemical, biochemical and microbiological practice].

    Science.gov (United States)

    Zolotarev, K V

    2012-08-01

    The researchers happen to face with suspensions in their chemical, biochemical and microbiological practice. The suspensions are the disperse systems with solid dispersed phase and liquid dispersion medium and with dispersed phase particle size > 100 nm (10-7 m). Quite often the necessity occurs to separate solid particles from liquid. To use for this purpose the precipitation in gravitation field can make the process to progress too long. In this respect an effective mode is the precipitation in the field of centrifugal forces--the centrifugation. The rotary speed of centrifuge rotor and centrifugation time can be set analytically using regularities of general dynamics and hydrodynamics. To this effect, should be written and transformed the equation of First and Second Newton Laws for suspension particle being in the field of centrifugal forces and forces of resistance of liquid and vessel wall. The force of liquid resistance depends on particle motion condition in liquid. To determine the regimen the Archimedes and Reynolds numerical dimensionless criteria are to be applied. The article demonstrates the results of these transformations as analytical inverse ratio dependence of centrifugation time from rotary speed. The calculation of series of "rate-time" data permits to choose the optimal data pair on the assumption of centrifuge capacity and practical reasonability. The results of calculations are validated by actual experimental data hence the physical mathematical apparatus can be considered as effective one. The setting progress depends both from parameter (Reynolds criterion) and data series calculation. So, the most convenient way to apply this operation is the programming approach. The article proposes to use the program Microsoft Excel and VBA programming language for this purpose. The possibility to download the file from Internet to use it for fast solution is proposed. PMID:23097986

  9. Magnetogravimetric Separation in a Rotational Device

    OpenAIRE

    Bunge, R. C.; Fuerstenau, D. W.

    1996-01-01

    Magnetogravimetric separation in a rotational device is a promising method for effecting sharp separation of minerals according to density. Separation is accomplished by two competing forces with opposite directions, namely the magnetic buoyancy and the centrifugal force. Magnetic buoyancy is experienced by particles which are suspended in a magnetic fluid when exposed to a non—homogeneous magnetic field. Since the magnetic buoyancy depends on particle volume whereas the centrifugal depends o...

  10. Centrifugation and the Manhattan Project

    Science.gov (United States)

    Reed, Cameron

    2009-05-01

    A study of U. S. Army Manhattan Engineer District documents reveals that consideration of centrifugation as a means of uranium enrichment during World War II was considerably more extensive than is commonly appreciated. By the time the centrifuge project was abandoned in early 1944 a full-scale prototype unit had been fabricated and tested at near-production speeds, enrichments of close to theoretically-expected levels had been demonstrated with pilot-plant units, and plans for production plants had been developed. This paper will review the history of this little-known aspect of the Project and examine the circumstances of how it came to be discontinued.

  11. Thermal hydrodynamic analysis of a countercurrent gas centrifuge

    International Nuclear Information System (INIS)

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  12. Theory and experiments on centrifuge cratering

    Science.gov (United States)

    Schmidt, R. M.; Holsapple, K. A.

    1980-01-01

    Centrifuge experimental techniques provide possibilities for laboratory simulation of ground motion and cratering effects due to explosive loadings. The results of a similarity analysis for the thermomechanical response of a continuum show that increased gravity is a necessary condition for subscale testing when identical materials for both model and prototype are being used. The general similarity requirements for this type of subscale testing are examined both theoretically and experimentally. The similarity analysis is used to derive the necessary and sufficient requirements due to the general balance and jump equations and gives relations among all the scale factors for size, density, stress, body forces, internal energy, heat supply, heat conduction, heat of detonation, and time. Additional constraints due to specific choices of material constitutive equations are evaluated separately. The class of constitutive equations that add no further requirements is identified. For this class of materials, direct simulation of large-scale cratering events at small scale on the centrifuge is possible and independent of the actual constitutive equations. For a rate-independent soil it is shown that a small experiment at gravity g and energy E is similar to a large event at 1 G but with energy equal to g3E. Consequently, experiments at 500 G with 8 grams of explosives can be used to simulate a kiloton in the field. A series of centrifuge experiments was performed to validate the derived similarity requirements and to determine the practicality of applying the technique to dry granular soils having little or no cohesion. Ten shots using Ottawa sand at various gravities confirmed reproducibility of results in the centrifuge environment, provided information on particle size effects, and demonstrated the applicability of the derived similitude requirements. These experiments used 0.5-4 grams of pentaerythritol-tetranitrate (PETN) and 1.7 grams of lead-azide explosives. They

  13. Empirical Design Considerations for Industrial Centrifugal Compressors

    OpenAIRE

    Cheng Xu; Amano, Ryoichi S.

    2012-01-01

    Computational Fluid Dynamics (CFD) has been extensively used in centrifugal compressor design. CFD provides further optimisation opportunities for the compressor design rather than designing the centrifugal compressor. The experience-based design process still plays an important role for new compressor developments. The wide variety of design subjects represents a very complex design world for centrifugal compressor designers. Therefore, some basic information for centrifugal design is still ...

  14. Performance of a Centrifugal Slurry Pump

    OpenAIRE

    Hawas Yahya Bajawi; Basharat Salim; Ziyadh Suhibani

    2014-01-01

    The aim of this study was to experimentally investigate the effect of speed, concentration and size of slurry on the performance of a centrifugal pump. For this purpose a facility was built where the performance of a centrifugal slurry pump was examined using aggregate slurry. Three sizes of slurry with three concentrations and at three impeller speeds were used for the performance investigations of a centrifugal slurry pump. As a reference performance the performance of centrifugal slurry pu...

  15. Centrifugal pumps for rocket engines

    Science.gov (United States)

    Campbell, W. E.; Farquhar, J.

    1974-01-01

    The use of centrifugal pumps for rocket engines is described in terms of general requirements of operational and planned systems. Hydrodynamic and mechanical design considerations and techniques and test procedures are summarized. Some of the pump development experiences, in terms of both problems and solutions, are highlighted.

  16. Laser and gas centrifuge enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, Olli [Senior Fellow, Belfer Center for Science and International Affairs, Harvard Kennedy School, Cambridge, Massachusetts (United States)

    2014-05-09

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  17. Laser and gas centrifuge enrichment

    Science.gov (United States)

    Heinonen, Olli

    2014-05-01

    Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

  18. Rotordynamic forces on centrifugal pump impellers

    Science.gov (United States)

    Franz, R.; Arndt, N.; Caughey, T. K.; Brennen, C. E.; Acosta, A. J.

    1987-01-01

    The asymmetric flow around an impeller in a volute exerts a force upon the impeller. To study the rotordynamic force on an impeller which is vibrating around its machine axis of rotation, the impeller, mounted on a dynamometer, is made to whirl in a circular orbit within the volute. The measured force is expressed as the sum of a steady radial force and an unsteady force due to the eccentric motion of the impeller. These forces were measured in separate tests on a centrifugal pump with radically increased shroud clearance, a two-dimensional impeller, and an impeller with an inducer, the impeller of the HPOTP (High Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine). In each case, a destabilizing force was observed over a region of positive whirl.

  19. Potential commercial applications of centrifuge technology

    International Nuclear Information System (INIS)

    As part of an effort to prevent the loss of and maximize the use of unique developments of the centrifuge program, this document identifies and briefly describes unclassified technologies potentially available for transfer. In addition, this document presents a preliminary plan for action needed to carry out the transfer activity. Continuing efforts will provide additional descriptions of technologies which have applications that are not as apparent or as obvious as those presented here. Declassification of some of the program information, now classified as restricted data, would permit the descriptions of additional technologies which have significant commercial potential. The following are major areas of technology where transfer opportunities exist: biomedical; separation; motors and control systems; materials; vacuum; dynamics and balancing; and diagnostics and instrumentation

  20. Liquid/Gas Vortex Separator

    Science.gov (United States)

    Morris, B. G.

    1986-01-01

    Liquid/gas separator vents gas from tank of liquid that contains gas randomly distributed in bubbles. Centrifugal force separates liquid and gas, forcing liquid out of vortex tube through venturi tube. Gas vented through exhaust port. When liquid detected in vent tube, exhaust port closed, and liquid/gas mixture in vent tube drawn back into tank through venturi.

  1. Effect of gelatin on the water dispersion and centrifugal purification of single-walled carbon nanotubes

    Science.gov (United States)

    Hanium Maria, Kazi; Mieno, Tetsu

    2016-01-01

    We report a convenient and effective procedure for the water dispersion and purification of single-walled carbon nanotubes (SWNTs). The purification procedure involves a combination of dispersion and centrifugation, in which gelatin; an environmentally friendly material is used as a dispersing agent. It has been found that an aqueous solution of gelatin effectively disperses SWNTs for more than a month. Another advantage of using gelatin as a dispersing agent is that it can be easily removed by washing with water and filtration. The centrifugation procedure employs a centrifugal force of about 2500 times the gravitational force to separate the particles. Although carbonaceous and metallic impurities usually have higher density than SWNTs in arc-produced carbon soot, the centrifugation can easily remove impurities leaving undamaged SWNTs in solution when appropriate centrifugal force and a centrifugation time are used. Centrifugation is carried out for three times to sufficiently remove impurities. Finally, the SWNTs are separated from the gelatin by heating in water and filtering.

  2. Fluidic Analysis in an Annular Centrifugal Contactor for Fuel Reprocessing

    International Nuclear Information System (INIS)

    An annular centrifugal contactor (ACC) is a promising device for fuel reprocessing process, because it offers several advantages—a smaller size, a smaller holdup volume, and a higher separation performance—over conventional contactors such as a mixer-settler and a pulse column. Fluid dynamics and dispersion in an ACC, which has a combined mixer/centrifuge structure, are closely related to its separation performance and capacity, and this information is useful in improving equipment design. In this paper, experimental and computational fluid dynamics (CFD) studies were conducted to analyze fluidic and dispersion behavior in ACCs. Multiphase mixing (water/TBP-dodecane/air) in the annular zone was observed by Particle Imaging Velocimetry, and the change in the fluidic and dispersion behavior was ascertained under several operational conditions. The results of the CFD studies, which considered multiphase turbulent flow in the annular and rotor interior zones, were in a good agreement with the experimental data. (author)

  3. Design of a centrifugal blood pump: Heart Turcica Centrifugal.

    Science.gov (United States)

    Demir, Onur; Biyikli, Emre; Lazoglu, Ismail; Kucukaksu, Suha

    2011-07-01

    A prototype of a new implantable centrifugal blood pump system named Heart Turcica Centrifugal (HTC) was developed as a left ventricular assist device (LVAD) for the treatment of end-stage cardiac failure. In the development of HTC, effects of blade height and volute tongue profiles on the hydraulic and hemolytic performances of the pump were investigated. As a result, the prototype was manufactured using the best blade height and volute tongue profiles. Performance of the prototype model was experimentally evaluated in a closed-loop flow system using water as the medium. The hydraulic performance requirement of an LVAD (5 L/min flow rate against a pressure difference of 100 mm Hg) was attained at 2800 rpm rotational speed.

  4. Centrifugal effects in a weakly ionized rotating gas

    International Nuclear Information System (INIS)

    The author deals with a weakly ionized gas rotating under the influence of the Lorentz force in a cylindrical vessel. This force occurs if an electrical current flows across a magnetic field. The investigation concerns the possibility to bring a neutral gas into rotation by a relatively small number of charged particles (ions and electrons) on which the Lorentz force is acting. Also the possibility to use the centrifugal force, due to the rotation of the gas, for mass separation, is discussed. (Auth.)

  5. Dynamical system analysis of unstable flow phenomena in centrifugal blower

    Directory of Open Access Journals (Sweden)

    Garcia David

    2015-09-01

    Full Text Available Methods of dynamical system analysis were employed to analyze unsteady phenomena in a centrifugal blower. Pressure signals gathered at different control points were decomposed into their Principal Components (PCs by means of Singular Spectrum Analysis (SSA. Certain number of PCs was considered in the analysis based on their statistical correlation. Projection of the original signal onto its PCs allowed to draw the phase trajectory that clearly separated non-stable blower working conditions from its regular operation.

  6. Comparison of Two Diffusers in a Transonic Centrifugal Compressor

    OpenAIRE

    Koji Nakagawa; Hiroshi Hayami; Yuichi Keimi

    2003-01-01

    Flow mechanisms suppressing the flow separation in two diffusers, a low-solidity cascade diffuser and a vaned diffuser with additional small vanes near the inlet, were compared mainly by numerical simulation. As the superiority of the low-solidity cascade diffuser was expected, a series of experiments was conducted using a transonic centrifugal compressor with a maximum pressure ratio of 7. The performance of the compressor with the vaned diffuser was comparable to that of the low-solidity ca...

  7. Cyber meets nuclear - Stuxnet and the cyberattacks on Iranian centrifuges

    International Nuclear Information System (INIS)

    In 2010 the computer worm Stuxnet attacked the information hardware of the Iranian uranium enrichment program. Stuxnet spread by USB flash drives and attacked SCADA software installed on Windows systems via several zero-day exploits. SCADA configures programmable logic controllers which control in the case of the Iranian centrifuge cascades frequency converter drives to choose the frequency of centrifuge motors. Thus the attackers were able to either change the rotation frequency of the rotor and thereby the separative power of the centrifuge or even destroy the fast spinning centrifuges by stopping and restarting them. The designers of Stuxnet must have had intimate knowledge of the facility design as e.g. the cascade connection scheme was programmed into Stuxnet. Based on this information some calculations of the Iranian cascade regarding the potential to produce highly enriched uranium will be presented using cascade simulation tools. The use of such highly sophisticated computer attacks to sabotage a nuclear program shed a new light on the debate about cyber attacks and the use of information technology for kinetic attacks in general. The talk will address problems the weaponization of information technology poses for international security and will highlight some more recent developments.

  8. Centrifuge pellet injector for JET

    International Nuclear Information System (INIS)

    An engineering design of a centrifuge pellet injector for JET is reported as part of the Phase I contract number JE 2/9016. A rather detailed design is presented for the mechanical and electronic features. Stress calculations, dynamic behaviour and life estimates are considered. The interfaces to the JET vacuum system and CODAS are discussed. Proposals for the pellet diagnostics (velocity, mass and shape) are presented. (orig.)

  9. Centrifugal pumps and allied machinery

    CERN Document Server

    Anderson, HH

    1994-01-01

    This book will be of vital interest to all engineers and designers concerned with centrifugal pumps and turbines. Including statistical information derived from 20000 pumps and 700 turbines with capacities of 5gpm to 5000000gpm, this book offers the widest range and scope of information currently available. Statistical analyses suggest practical methods of increasing pump performance and provide valuable data for new design aspects.

  10. RELATIONSHIP BETWEEN WHEAT MILLING STREAM QUALITY AND SEPARATION EFFECT OF WHEAT STARCH AND GLUTEN BY CENTRIFUGAL PROCESS%系统粉品质与离心法小麦淀粉和谷朊粉分离效果的关系

    Institute of Scientific and Technical Information of China (English)

    郑学玲; 赵波; 郑坤

    2011-01-01

    Selecting 21 flour samples from different milling systems, we studied the relationship between the wheat milling stream quality and the separation effect of wheat starch and gluten by centrifugal process. The results showed that the quality properties of the flour samples from different systems and its influences on the separation effect were different from each other. The correlation analysis of the separation effect showed that the bran speck content and the ash content were in highly significant negative correlation with the A starch yield, and in highly significant positive correlation with the dry gluten yield; the water absorption rate was in significant positive correlation with the A starch yield, but in highly significant negative correlation with the dry gluten yield; and the gluten index had no obvious correlation with the A starch yield and the dry gluten yield. The results showed that the bran speck content and the ash content had high effects on the starch separation effect;and the higher the bran speck content and the ash content were, the lower the starch yield was, and the higher the dry gluten yield was.%以制粉系统各粉路抽取的21个面粉样品为材料,研究样品的品质特性及其对离心法分离淀粉和谷朊粉效果的影响.结果表明:粉路各系统面粉样品的品质特性及淀粉与谷朊粉分离效果存在着不同程度的差异.对分离效果的相关性分析表明:麸星含量和灰分含量均与A淀粉得率呈极显著负相关,与面筋得率呈极显著正相关;湿面筋含量与A淀粉得率呈显著负相关,与面筋得率呈极显著正相关;吸水率与A淀粉得率呈显著正相关,与面筋得率呈极显著负相关;面筋指数与A淀粉和面筋得率无明显相关性.这说明麸星含量和灰分含量对淀粉分离效果的影响较大,二者含量越高,A淀粉得率就越低,而面筋得率则越高.

  11. High Efficiency Centrifugal Compressor for Rotorcraft Applications

    Science.gov (United States)

    Medic, Gorazd; Sharma, Om P.; Jongwook, Joo; Hardin, Larry W.; McCormick, Duane C.; Cousins, William T.; Lurie, Elizabeth A.; Shabbir, Aamir; Holley, Brian M.; Van Slooten, Paul R.

    2014-01-01

    measured at design flow rate and speed. The measured efficiency and stall margin were lower than pre-test CFD predictions by 2.4 percentage points (pt) and 4.5 pt, respectively. Initial impressions from the experimental data indicated that the loss in the efficiency and stall margin can be attributed to a design shortfall in the impeller. However, detailed investigation of experimental data and post-test CFD simulations of higher fidelity than pre-test CFD, and in particular the unsteady CFD simulations and the assessment with a wider range of turbulence models, have indicated that the loss in efficiency is most likely due to the impact of unfavorable unsteady impeller/diffuser interactions induced by diffuser vanes, an impeller/diffuser corrected flow-rate mismatch (and associated incidence levels), and, potentially, flow separation in the radial-to-axial bend. An experimental program with a vaneless diffuser is recommended to evaluate this observation. A subsequent redesign of the diffuser (and the radial-to-axial bend) is also recommended. The diffuser needs to be redesigned to eliminate the mismatching of the impeller and the diffuser, targeting a slightly higher flow capacity. Furthermore, diffuser vanes need to be adjusted to align the incidence angles, to optimize the splitter vane location (both radially and circumferentially), and to minimize the unsteady interactions with the impeller. The radial-to-axial bend needs to be redesigned to eliminate, or at least minimize, the flow separation at the inner wall, and its impact on the flow in the diffuser upstream. Lessons were also learned in terms of CFD methodology and the importance of unsteady CFD simulations for centrifugal compressors was highlighted. Inconsistencies in the implementation of a widely used two-equation turbulence model were identified and corrections are recommended. It was also observed that unsteady simulations for centrifugal compressors require significantly longer integration times than what

  12. An ideal cascade for uranium 235 enrichment by centrifuge jet nozzle process

    International Nuclear Information System (INIS)

    The design of an ideal cascade for the process of isotope separation by centrifugation for the U235 enrichment, is presented. A selection of building materials used in fabrication of isotope separation plants, showing the importance of aluminium, due the bauxite mines in Northern Brazil, is done. (M.C.K.)

  13. Multiphase flow modeling in centrifugal partition chromatography.

    Science.gov (United States)

    Adelmann, S; Schwienheer, C; Schembecker, G

    2011-09-01

    The separation efficiency in Centrifugal Partition Chromatography (CPC) depends on selection of a suitable biphasic solvent system (distribution ratio, selectivity factor, sample solubility) and is influenced by hydrodynamics in the chambers. Especially the stationary phase retention, the interfacial area for mass transfer and the flow pattern (backmixing) are important parameters. Their relationship with physical properties, operating parameters and chamber geometry is not completely understood and predictions are hardly possible. Experimental flow visualization is expensive and two-dimensional only. Therefore we simulated the flow pattern using a volume-of-fluid (VOF) method, which was implemented in OpenFOAM®. For the three-dimensional simulation of a rotating FCPC®-chamber, gravitational centrifugal and Coriolis forces were added to the conservation equation. For experimental validation the flow pattern of different solvent systems was visualized with an optical measurement system. The amount of mobile phase in a chamber was calculated from gray scale values of videos recorded by an image processing routine in ImageJ®. To visualize the flow of the stationary phase polyethylene particles were used to perform a qualitative particle image velocimetry (PIV) analysis. We found a good agreement between flow patterns and velocity profiles of experiments and simulations. By using the model we found that increasing the chamber depth leads to higher specific interfacial area. Additionally a circular flow in the stationary phase was identified that lowers the interfacial area because it pushes the jet of mobile phase to the chamber wall. The Coriolis force alone gives the impulse for this behavior. As a result the model is easier to handle than experiments and allows 3D prediction of hydrodynamics in the chamber. Additionally it can be used for optimizing geometry and operating parameters for given physical properties of solvent systems. PMID:21324465

  14. Centrifuge facilities at Technical University of Denmark

    DEFF Research Database (Denmark)

    Leth, Caspar Thrane; Krogsbøll, Anette Susanne; Hededal, Ole

    2008-01-01

    The geotechnical group at the Danish Technical University (DTU) operates a geotechnical beam centrifuge. The centrifuge was build in 1976 and has been upgraded through the years, latest with onboard data and control systems. The centrifuge concept involves an increased gravity field in which...... the physical model is placed and tested. The capabilities of the centrifuge at DTU makes it possible to obtain a scale factor of 75-85 in the tests which equals a soil volume in prototype scale of ø40m and a depth of 36 m. The centrifuge facilities at DTU have through the years been used for testing various...... geotechnical issues, such as suction anchors, tension piles in clay, active earth pressures on sheet piles and group effects for lateral loaded piles. The paper describes physical modelling in general, the centrifuge, present setups and shows samples of obtained results....

  15. Empirical Design Considerations for Industrial Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    Cheng Xu

    2012-01-01

    Full Text Available Computational Fluid Dynamics (CFD has been extensively used in centrifugal compressor design. CFD provides further optimisation opportunities for the compressor design rather than designing the centrifugal compressor. The experience-based design process still plays an important role for new compressor developments. The wide variety of design subjects represents a very complex design world for centrifugal compressor designers. Therefore, some basic information for centrifugal design is still very important. The impeller is the key part of the centrifugal stage. Designing a highly efficiency impeller with a wide operation range can ensure overall stage design success. This paper provides some empirical information for designing industrial centrifugal compressors with a focus on the impeller. A ported shroud compressor basic design guideline is also discussed for improving the compressor range.

  16. Methodology for optimally sized centrifugal partition chromatography columns.

    Science.gov (United States)

    Chollet, Sébastien; Marchal, Luc; Jérémy Meucci; Renault, Jean-Hugues; Legrand, Jack; Foucault, Alain

    2015-04-01

    Centrifugal Partition Chromatography (CPC) is a separation process based on the partitioning of solutes between two partially miscible liquid phases. There is no solid support for the stationary phase. The centrifugal acceleration is responsible for both stationary phase retention and mobile phase dispersion. CPC is thus a process based on liquid-liquid mass transfer. The separation efficiency is mainly influenced by the hydrodynamics of the phases in each cell of the column. Thanks to a visualization system, called "Visual CPC", it was observed that the mobile phase can flow through the stationary phase as a sheet, or a spray. Hydrodynamics, which directly governs the instrument efficiency, is directly affected during scale changes, and non-linear phenomena prevent the successful achievement of mastered geometrical scale changes. In this work, a methodology for CPC column sizing is proposed, based on the characterization of the efficiency of advanced cell shapes, taking into account the hydrodynamics. Knowledge about relationship between stationary phase volume, cell efficiency and separation resolution in CPC allowed calculating the optimum cell number for laboratory and industrial scale CPC application. The methodology is highlighted with results on five different geometries from 25 to 5000 mL, for two applications: the separation of alkylbenzene by partitioning with heptane/methanol/water biphasic system; and the separation of peptides by partitioning with n-butanol/acetic acid/water (4/1/5) biphasic system. With this approach, it is possible to predict the optimal CPC column length leading to highest productivity.

  17. Effect of Centrifugation on Sesame Paste Temperature

    Directory of Open Access Journals (Sweden)

    Ahmad Kouchakzadeh

    2012-01-01

    Full Text Available The sesame seeds were mechanically cold pressed at temperature below 45 then centrifuged. No chemicals were used. The temperature during centrifugation of sesame paste was recorded. Temperatures in less than one hour operation has elevated to 148, 273 and 315 in 1200, 1800 and 2400 G-force centrifugal acceleration, respectively. since the centrifugal accelerations during the process cut at 1200, 1800 and 2400 G-force at about 35, 20 and 10 minutes, respectively. The maximum allowable temperatures raised to about 100 . Linear and quadratics regression model were fitted to data.

  18. Cavitation Effects in Centrifugal Pumps- A Review

    Directory of Open Access Journals (Sweden)

    Maxime Binama

    2016-05-01

    Full Text Available Cavitation is one of the most challenging fluid flow abnormalities leading to detrimental effects on both the centrifugal pump flow behaviors and physical characteristics. Centrifugal pumps’ most low pressure zones are the first cavitation victims, where cavitation manifests itself in form of pitting on the pump internal solid walls, accompanied by noise and vibration, all leading to the pump hydraulic performance degradation. In the present article, a general description of centrifugal pump performance and related parameters is presented. Based on the literature survey, some light were shed on fundamental cavitation features; where different aspects relating to cavitation in centrifugal pumps were briefly discussed

  19. Virgin Coconut Oil Production by Centrifugation Method

    Directory of Open Access Journals (Sweden)

    Y.C.Wong

    2014-03-01

    Full Text Available The virgin coconut oil (VCO production by centrifugation method was studied. The production of VCO was studied by using various centrifugation speed, temperature and time intervals. The results showed that the yield of VCO was 13.53% at 12000rpm, at 120 minutes. The highest yield of VCO was 13.80% at centrifugation temperature of 40oC. The concentration of lauric acid present in the samples with variables of centrifugation temperatures, speed, and time intervals were 0.4543µg, 6.2367µg, and 6.4894µg respectively.

  20. CFD simulation of centrifugal cells washers.

    Science.gov (United States)

    Kellet, Beth E; Binbing, Han; Dandy, David S; Wickramasinghe, S Ranil

    2004-01-01

    The feasibility of using computational fluid dynamics to guide the design of better centrifuges for processing shed blood is explored here. The velocity field and the rate of protein removal from the shed blood have been studied. The results indicate that computational fluid dynamics could help screen preliminary centrifuge bowl designs thus reducing the number of initial experimental tests required when developing new centrifuge bowls. Though the focus of this work is on washing shed blood the methods developed here are applicable to the design of centrifuge bowls for other blood processing applications. PMID:15133962

  1. Numerical investigation of suction vortices behavior in centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    An, Young Joon; Shin, Byeong Rog [Changwon National University, Changwon (Korea, Republic of)

    2011-03-15

    A numerical simulation on suction vortices behavior in a centrifugal pump was carried out to investigate their influence on the internal flow through impellers including formation and shedding of cavitation by using a finite-volume method and k-{omega} Shear Stress Transport turbulence model. For cavitating flow, a two phase homogeneous cavitation model was used. A full three-dimensional flow in a single section centrifugal pump consisting of a six blade impeller and shroud ring was computed with structured mesh. A constant suction vortex is imposed as a boundary condition. Vortices behavior was investigated according to the variation of flow rates of two pump systems with and without suction vortices. From the results, suction vortices induced biased flow structure and more cavitations, especially at the low flow rate condition. Complicated internal flow phenomena through impellers such as formation of cavitations, growing and shedding of the vortex, flow separation and flow unsteadiness due to the suction vortices are investigated and discussed.

  2. Numerical investigation of suction vortices behavior in centrifugal pump

    International Nuclear Information System (INIS)

    A numerical simulation on suction vortices behavior in a centrifugal pump was carried out to investigate their influence on the internal flow through impellers including formation and shedding of cavitation by using a finite-volume method and k-ω Shear Stress Transport turbulence model. For cavitating flow, a two phase homogeneous cavitation model was used. A full three-dimensional flow in a single section centrifugal pump consisting of a six blade impeller and shroud ring was computed with structured mesh. A constant suction vortex is imposed as a boundary condition. Vortices behavior was investigated according to the variation of flow rates of two pump systems with and without suction vortices. From the results, suction vortices induced biased flow structure and more cavitations, especially at the low flow rate condition. Complicated internal flow phenomena through impellers such as formation of cavitations, growing and shedding of the vortex, flow separation and flow unsteadiness due to the suction vortices are investigated and discussed

  3. Waste minimization and resource recovery using centrifugation and thermal desorption

    International Nuclear Information System (INIS)

    Separation and Recovery Systems, Inc. (SRS) provides on-site waste minimization and resource recovery using its state-of-the-art MX-1500 centrifuge and MX-2000 thermal desorber. The MX-1500 can process over 450 feed tons of material per day, resulting in centrifuged cake containing 20% to 60% by weight. The MX-2000 is a hollow-flite thermal processor indirectly heated by either steam or hot oil. SRS has dewatered and/or deoiled over 1,000,000 feed tons of material in the refining, chemical, and energy industries using the MX-1500. SRS estimates that over 300,000 barrels of reusable oil have been recovered from that material. Additionally, SRS has dried and/or detoxified over 150,000 wet tons of solids or soil to regulatory or customer-specified limits using the MX-2000

  4. Centrifugal quantum states of neutrons

    Science.gov (United States)

    Nesvizhevsky, V. V.; Petukhov, A. K.; Protasov, K. V.; Voronin, A. Yu.

    2008-09-01

    We propose a method for observation of the quasistationary states of neutrons localized near a curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror Fermi potential. This phenomenon is an example of an exactly solvable “quantum bouncer” problem that can be studied experimentally. It could provide a promising tool for studying fundamental neutron-matter interactions, as well as quantum neutron optics and surface physics effects. We develop a formalism that describes quantitatively the neutron motion near the mirror surface. The effects of mirror roughness are taken into account.

  5. Mathematical modeling of mass transfer during centrifugal filtration of polydisperse suspensions

    Energy Technology Data Exchange (ETDEWEB)

    V.F. Pozhidaev; Y.B. Rubinshtein; G.Y. Golberg; S.A. Osadchii [Dahl East Ukraine National University, Lugansk (Ukraine)

    2009-07-15

    A mass-transfer equation, the solution of which for given boundary conditions makes it possible to derive in analytical form a relationship between the extraction of the solid phase of a suspension into the centrifuge effluent and the fineness of the particles, is suggested on the basis of a model; this is of particular importance in connection with the development of a new trend in the utilization of filtering centrifuges - concentration of coal slurries by extraction into the centrifuge effluent of the finest particles, the ash content of which is substantially higher than that of particles of the coarser classes. Results are presented for production studies under conditions at an active establishment (the Neryungrinskaya Enrichment Factory); these results confirmed the adequacy of the mathematical model proposed: convergence of computed and experimental data was within the limits of the experimental error (no more than 3%). The model in question can be used to predict results of suspension separation by centrifugal filtration.

  6. Benefication of coking-coal slimes by means of screen centrifuges

    Energy Technology Data Exchange (ETDEWEB)

    S.A. Osadchii; E.K. Samoilova; G.Y. Gol' berg [Coal Preparation Plant Neryungrinskaya, Neryungri (Russian Federation)

    2009-06-15

    A new slime-benefication technology has been developed at Coal Preparation Plant Neryungrinskaya. In this technology, the product is separated in screen centrifuges. As a result, small particles with relatively high ash content are extracted in the centrifugate. Correspondingly, the cake has the required ash content of {le} 10%. Industrial tests indicate that this technology is feasible at the facility. The parameters that ensure most effective slime separation are determined. The new slime-benefication system is simple and characterized by relatively low operating costs: the expected reduction in production costs relative to the existing technology is about 126 million rub/yr.

  7. Centrifuge modelling of offshore monopile foundation

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Hededal, Ole

    2010-01-01

    centrifuge tests on a laterally loaded monopile in dry sand. The prototype dimension of the piles was modelled to a diameter of 1 meter and penetration depth on 6 meter. The test series were designed in order to investigate the scaling laws in the centrifuge both for monotonic and cyclic loading...

  8. Centrifugal innervation of the mammalian olfactory bulb.

    Science.gov (United States)

    Matsutani, Shinji; Yamamoto, Noboru

    2008-12-01

    Although it has been known for decades that the mammalian olfactory bulb receives a substantial number of centrifugal inputs from other regions of the brain, relatively few data have been available on the function of the centrifugal olfactory system. Knowing the role of the centrifugal projection and how it works is of critical importance to fully understanding olfaction. The centrifugal fibers can be classified into two groups, a group that release neuromodulators, such as noradrenaline, serotonin, or acetylcholine, and a group originating in the olfactory cortex. Accumulating evidence suggests that centrifugal neuromodulatory inputs are associated with acquisition of odor memory. Because the distribution of the terminals on these fibers is diffuse and widespread, the neuromodulatory inputs must affect diverse subsets of bulbar neurons at the same time. In contrast, knowledge of the role of centrifugal fibers from the olfactory cortical areas is limited. Judging from recent morphological evidence, these fibers may modify the activity of neurons located in sparse and discrete loci in the olfactory bulb. Given the modular organization of the olfactory bulb, centrifugal fibers from the olfactory cortex may help coordinate the activities of restricted subsets of neurons belonging to distinct functional modules in an odor-specific manner. Because the olfactory cortex receives inputs from limbic and neocortical areas in addition to inputs from the bulb, the centrifugal inputs from the cortex can modulate odor processing in the bulb in response to non-olfactory as well as olfactory cues.

  9. High frequency dynamics in centrifugal compressors

    NARCIS (Netherlands)

    Twerda, A.; Meulendijks, D.; Smeulers, J.P.M.; Handel, R. van den; Lier, L.J. van

    2008-01-01

    Problems with centrifugal compressors relating to high frequency, i.e. Blade passing frequency (BPF) are increasing. Pulsations and vibrations generated in centrifugal compressors can lead to nuisance, due to strong tonal noise, and even breakdown. In several cases the root cause of a failure or a n

  10. Rotor for a pyrolysis centrifuge reactor

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a rotor for a pyrolysis centrifuge reactor, said rotor comprising a rotor body having a longitudinal centre axis, and at least one pivotally mounted blade being adapted to pivot around a pivot axis under rotation of the rotor body around the longitudinal centre axis....... Moreover, the present invention relates to a pyrolysis centrifuge reactor applying such a rotor....

  11. Control system modeling of a centrifuge

    International Nuclear Information System (INIS)

    Improved control of a centrifuge can be achieved by using a mathematical model. This model is a linear, time-invariant, second order model which relates the input to the output of the centrifuge. After the Z-transform of the model was taken, a digital computer program was written to implement the model. The model parameters were optimized through correlation of the theoretical output as compared with the actual output of the centrifuge. As a result, a model was developed that simulated the centrifuge. Traditionally, a desired centrifuge output was produced by an input which was determined by trial and error. However, using the model with the desired output curve, the necessary input can be calculated with the digital computer program

  12. Separators for flywheel rotors

    Science.gov (United States)

    Bender, Donald A.; Kuklo, Thomas C.

    1998-01-01

    A separator forms a connection between the rotors of a concentric rotor assembly. This separator allows for the relatively free expansion of outer rotors away from inner rotors while providing a connection between the rotors that is strong enough to prevent disassembly. The rotor assembly includes at least two rotors referred to as inner and outer flywheel rings or rotors. This combination of inner flywheel ring, separator, and outer flywheel ring may be nested to include an arbitrary number of concentric rings. The separator may be a segmented or continuous ring that abuts the ends of the inner rotor and the inner bore of the outer rotor. It is supported against centrifugal loads by the outer rotor and is affixed to the outer rotor. The separator is allowed to slide with respect to the inner rotor. It is made of a material that has a modulus of elasticity that is lower than that of the rotors.

  13. Spiral fluid separator

    Science.gov (United States)

    Robertson, Glen A. (Inventor)

    1993-01-01

    A fluid separator for separating particulate matter such as contaminates is provided which includes a series of spiral tubes of progressively decreasing cross sectional area connected in series. Each tube has an outlet on the outer curvature of the spiral. As fluid spirals down a tube, centrifugal force acts to force the heavier particulate matter to the outer wall of the tube, where it exits through the outlet. The remaining, and now cleaner, fluid reaches the next tube, which is smaller in cross sectional area, where the process is repeated. The fluid which comes out the final tube is diminished of particulate matter.

  14. Design of centrifugal impeller blades

    Science.gov (United States)

    Betz, A; Flugge-Lotz, I

    1939-01-01

    This paper restricts itself to radial impellers with cylindrical blades since, as Prasil has shown, the flow about an arbitrarily curved surface of revolution may be reduced to this normal form we have chosen by a relatively simple conformal transformation. This method starts from the simple hypotheses of the older centrifugal impeller theory by first assuming an impeller with an infinite number of blades. How the flow is then modified is then investigated. For the computation of flow for a finite number of blades, the approximation method as developed by Munk, Prandtl and Birnbaum, or Glauert is found suitable. The essential idea of this method is to replace the wing by a vortex sheet and compute the flow as the field of these vortices. The shape of the blades is then obtained from the condition that the flow must be along the surface of the blade.

  15. Investigation on centrifugal impeller in an axial-radial combined compressor with inlet distortion

    Science.gov (United States)

    Li, Du; Yang, Ce; Zhao, Ben; Zhou, Mi; Qi, Mingxu; Zhang, Jizhong

    2011-12-01

    Assembling an axial rotor and a stator at centrifugal compressor upstream to build an axial-radial combined compressor could achieve high pressure ratio and efficiency by appropriate size augment. Then upstream potential flow and wake effect appear at centrifugal impeller inlet. In this paper, the axial-radial compressor is unsteadily simulated by three-dimensional Reynolds averaged Navier-Stokes equations with uniform and circumferential distorted total pressure inlet condition to investigate upstream effect on radial rotor. The results show that span-wise nonuniform total pressure distribution is generated and radial and circumferential combined distortion is formed at centrifugal rotor inlet. The upstream stator wake deflects to rotor rotation direction and decreases with blade span increases. Circumferential distortion causes different separated flow formations at different pitch positions. The tip leakage vortex is suppressed in centrifugal blade passages. Under distorted inlet condition, flow direction of centrifugal impeller leading edge upstream varies evidently near hub and shroud but varies slightly at mid-span. In addition, compressor stage inlet distortion produces remarkable effect on blade loading of centrifugal blade both along chordwise and pitchwise.

  16. Centrifuge workers study. Phase II, completion report

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, H.D.

    1994-09-01

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom.

  17. Centrifuge workers study. Phase II, completion report

    International Nuclear Information System (INIS)

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom

  18. Fault Detection and Isolation in Centrifugal Pumps

    DEFF Research Database (Denmark)

    Kallesøe, Carsten

    Centrifugal pumps are used in a variety of different applications, such as water supply, wastewater, and different industrial applications. Some pump installations are crucial for the applications to work. Failures can lead to substantial economic losses and can influence the life of many people...... is placed. The topic of this work is Fault Detection and Identification in centrifugal pumps. Different approaches are developed with special focus on robustness. Robustness with respect to disturbances, unknown parts of the system, and parameter variations are considered. All developed algorithms...... are tested on an industrial test setup, showing the usability of the algorithms on a real centrifugal pump....

  19. Modeling of Centrifugal Force Field and the Effect on Filling and Solidification in Centrifugal Casting

    Science.gov (United States)

    Sheng, Wenbin; Ma, Chunxue; Gu, Wanli

    2011-06-01

    Based on the steady flow in a tube, a mathematical model has been established for the consideration of centrifuging force field by combining the equations of continuity, conservation of momentum and general energy. Effects of centrifugal field on the filling and solidification are modeled by two accessional terms: centrifugal force and Chorios force. In addition, the transfer of heat by convection is considered to achieve a coupling calculation of velocity field and temperature field. The solution of pressure item is avoided by introducing the stream function ψ(x,y) and the eddy function ξ(x,y). Corresponding difference formats for the simultaneous equations of centrifugal filling, the accessional terms and the solidifying latent heat have been established by the finite difference technique. Furthermore, the centrifugal filling and solidification processes in a horizontal tube are summarized to interpret the mechanism by which internal defects are formed in centrifugal castings.

  20. Molecular structure and centrifugal distortion in methylthioethyne

    NARCIS (Netherlands)

    Engelsen, D. den

    1969-01-01

    The investigation of the microwave spectra of five isotopic species of methylthioethyne, HCCSCH3 enabled a fairly reliable calculation to be made of bond lengths and angles. The centrifugal distortion parameters are related to molecular vibrations.

  1. Geotechnical Centrifuge Studies of Unsaturated Transport

    Science.gov (United States)

    Smith, R. W.; Mattson, E. D.; Palmer, C. D.

    2007-12-01

    Improved understanding of contaminant migration in heterogeneous, variably saturated porous media is required to better define the long-term stewardship requirements for U.S. Department of Energy (DOE) lands and to assist in the design of effective vadose-zone barriers to contaminant migrations. A geotechnical centrifuge provides an experimental approach to explore vadose zone transport over a wide range of relevant conditions in time frames not possible for conventional bench-top experiments. Our research to date resulted in the design, construction, and testing of in-flight experimental apparatus allowing the replication of traditional bench top unsaturated transport experiments using the 2-meter radius geotechnical centrifuge capabilities at the Idaho National Laboratory. Additionally we conducted a series of unsaturated 1-dimenstional column experiments using conservative tracers to evaluate the effects of increased centrifugal acceleration on derived transport properties and assessing the scaling relationships for these properties. Our experimental results indicated that breakthrough times for a conservative tracer decreased significantly and systematically as a function of increased centrifugal acceleration. Differences between these experimental results and estimates based on predictive scaling rules are due to slight moisture content differences between experiments at different centrifugal accelerations. In contrast, dispersion coefficients varied systemically with centrifugal acceleration in accordance with predictive scaling rules. The results we obtained in this study indicate that the centrifuge technique is a viable experimental method for the study of subsurface processes where gravitational acceleration is important. The geotechnical centrifuge allows experiments to be completed more quickly than tests conducted at 1-gravity and can be used to experimentally address important scaling issues, and permits experiments under a range of conditions that

  2. Towards Centrifugal Compressor Stages Virtual Testing

    OpenAIRE

    Guidotti, Emanuele

    2014-01-01

    Flow features inside centrifugal compressor stages are very complicated to simulate with numerical tools due to the highly complex geometry and varying gas conditions all across the machine. For this reason, a big effort is currently being made to increase the fidelity of the numerical models during the design and validation phases. Computational Fluid Dynamics (CFD) plays an increasing role in the assessment of the performance prediction of centrifugal compressor stages. Historically, CFD wa...

  3. Meridional Considerations of the Centrifugal Compressor Development

    OpenAIRE

    Xu, C.; Amano, R. S.

    2012-01-01

    Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some ...

  4. Finite element analysis of centrifugal impellers

    OpenAIRE

    Sham Sunder, K.

    1981-01-01

    A three-dimensional method of stress analysis using finite element techniques is presented for determining the stress distribution in centrifugal impellers. It can treat all of the three types of loading possible in an inpeller, viz centrifugal, thermal and fluid. The method has no known limitations with regards to the geometric factors such as asymnetry of disk, blade curvature, presence of a cover disk or shroud, single or double sided impeller etc. A comparison of r...

  5. CFD Analysis of Centrifugal Pump: A Review

    OpenAIRE

    Narayan P. Jaiswal

    2014-01-01

    The main objective of this work is to understand role of the computational fluid dynamics (CFD) technique in analyzing and predicting the performance of centrifugal pump. Computational Fluid Dynamics (CFD) is the present day state-of-art technique for fluid flow analysis. The critical review of CFD analysis of CFD analysis of centrifugal pump along with future scope for further improvement is presented in this paper. Different solver like ANSYS-CFX, FLUENT etc can be used for ...

  6. Return Vane Installed in Multistage Centrifugal Pump

    OpenAIRE

    Miyano, Masafumi; Kanemoto, Toshiaki; Kawashima, Daisuke; Wada, Akihiro; Hara, Takashi; Sakoda, Kazuyuki

    2008-01-01

    To optimize the stationary components in the multistage centrifugal pump, the effects of the return vane profile on the performances of the multistage centrifugal pump were investigated experimentally, taking account of the inlet flow conditions for the next stage impeller. The return vane, whose trailing edge is set at the outer wall position of the annular channel downstream of the vane and which discharges the swirl-less flow, gives better pump performances. By equipping such return vane w...

  7. Enrichment technology. Dependable vendor of gas centrifuges

    International Nuclear Information System (INIS)

    Enrichment Technology is an innovative, high-tech company that develops, manufactures and installs gas centrifuges for enriching uranium. In addition, Enrichment Technology designs enrichment plants that use gas centrifuge technology. This technology offers the most efficient and cost-effective method for enriching uranium yet: high-performance, safe technology that dominates the market with a global share of 45 percent. A determining factor in Enrichment Technology's success is its mission: supplying its customers with safe, reliable technology. Production of the centrifuges requires versatile know-how and collaboration between different departments as well as interdisciplinary teams at the various sites. More than 2000 operators at 8 sites in 5 countries contribute their individual knowledge and personal skills in order to produce this exceptional technology. The head office is in Beaconsfield near London and the operational headquarters are in Almelo in the Netherlands. There are other sites in Germany (Juelich und Gronau), Great Britain (Capenhurst) as well as project sites in the USA and France. Capenhurst is where experienced engineers design new enrichment plants and organise their construction. Centrifuge components are manufactured in Almelo and Juelich, while the pipework needed to connect up the centrifuges is produced at the site in Gronau. In Juelich, highly qualified scientists in interdisciplinary teams are continuously researching ways of improving the current centrifuges. Communication between specialists in the fields of chemistry, physics and engineering forms the basis for the company's success and the key to extending this leading position in the global enrichment market. (orig.)

  8. Clinical experience with the Sarns centrifugal pump.

    Science.gov (United States)

    Curtis, J J; Walls, J T; Demmy, T L; Boley, T M; Schmaltz, R A; Goss, C F; Wagner-Mann, C C

    1993-07-01

    Since October 1986, we have had experience with 96 Sarns centrifugal pumps in 72 patients (pts). Heparinless left atrial to femoral artery or aorta bypass was used in 14 pts undergoing surgery on the thoracic aorta with 13 survivors (93%). No paraplegia or device-related complications were observed. In 57 patients, the Sarns centrifugal pump was used as a univentricular (27 pts) or biventricular (30 pts) cardiac assist device for postcardiotomy cardiogenic shock. In these patients, cardiac assist duration ranged from 2 to 434 h with a hospital survival rate of 29% in those requiring left ventricular assist and 13% in those requiring biventricular assist. Although complications were ubiquitous in this mortally ill patient population, in 5,235 pump-hours, no pump thrombosis was observed. Hospital survivors followed for 4 months to 6 years have enjoyed an improved functional class. We conclude that the Sarns centrifugal pump is an effective cardiac assist device when used to salvage patients otherwise unweanable from cardiopulmonary bypass. Partial left ventricular bypass using a centrifugal pump has become our procedure of choice for unloading the left ventricle and for maintenance of distal aortic perfusion pressure when performing surgery on the thoracic aorta. This clinical experience with the Sarns centrifugal pump appears to be similar to that reported with other centrifugal assist devices.

  9. Body height and arterial pressure in seated and supine young males during +2 G centrifugation

    DEFF Research Database (Denmark)

    Arvedsen, Sine K.; Eiken, Ola; Kölegård, Roger;

    2015-01-01

    by the use of a human centrifuge would increase mean arterial pressure (MAP) more in tall than in short males in the seated position. In short (162-171cm, n=8) and tall (194-203cm, n=10) healthy males (18-41yr), brachial arterial pressure, heart rate (HR) and cardiac output were measured during +2G...... centrifugation, while they were seated upright with the legs kept horizontal (+2Gz). In a separate experiment, the same measurements were done with the subjects supine (+2Gx). During +2Gz MAP increased in the short (22±2 mmHg, P 

  10. Uranium enrichment using gas centrifugation. An analysis focusing export control; Urananrikning med gascentrifugering. En analys med fokus paa exportkontroll

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina [Swedish Defense Research Inst., Stockholm (Sweden)

    2005-08-01

    The Swedish Defence Research Agency, FOI, has performed a study on uranium enrichment by gas centrifugation. The theory and principles of gas centrifugation is described in this report and relevant equipment used in the process has been identified. Different aspects of operating a gas centrifuge facility - and its indicators - are also presented. The separation efficiency and the flow of material through a centrifuge are very small, and therefore, a large number of centrifuges in cascades is needed to produce a larger amount of enriched uranium within a reasonable time. Countries with nuclear weapons ambitions often show an interest in gas centrifuges to produce weapons grade uranium - if they have managed to acquire the technology - because of the efficiency of the process and since it is relatively easy to conceal. Most equipment used in gas centrifuge facilities is under export control to prevent clandestine uranium enrichment. The Nuclear Suppliers' Group has compiled lists of nuclear related equipment and components that are of importance to export control. The control lists have also been included in the EU legislation.

  11. Numerical and experimental investigation of the centrifugal stage axial compressor centrifugal stationary GTE

    OpenAIRE

    Шаровский, Михаил Антонович; Усатенко, Елена Александровна; Шелковский, Михаил Юрьевич; Зубрицкая, Инна Аркадьевна

    2012-01-01

    About increase in efficiency of a centrifugal step of the compressor in low-dimensional GTD with the osetsentrobezhny compressor. Use of the “closed” driving wheel as basic possibility of receiving a highly effective centrifugal step. The gazodinamichesky aspect of its design and manufacturing is considered.

  12. Clinical use of centrifugal pumps and the roller pump in open heart surgery: a comparative evaluation.

    Science.gov (United States)

    Yoshikai, M; Hamada, M; Takarabe, K; Okazaki, Y; Ito, T

    1996-06-01

    Centrifugal pumps have been used widely as the main pump in open heart surgery to reduce damage to blood elements and to reduce the activation of the coagulation system. The purpose of this study was the evaluation and comparison of the effects of two types of centrifugal pumps and of one type of roller pump on blood elements, the coagulation system, complements, and immunoglobulins. Two types of centrifugal pumps (Lifestream; St. Jude Medical, Chelmsford, Massachusetts; and BP-80: Medtronic, BioMedicus, Inc., Eden Prairie, Minnesota, U.S.A.) and one roller pump (Mera Co.) were used separately as the main pump for cardiopulmonary bypass (CPB) in 29 patients. Platelet counts, lactate dehydrogenase, antithrombin III, thrombin-antithrombin complex (TAT), complements (C3, C4, and CH50) and immunoglobulins G, A, and M values were measured before and after CPB and compared. Values, except those for TAT, showed no significant difference among the three groups. The TAT values increased less in each of the centrifugal pump groups than in the roller pump group. This finding suggests that thrombin synthesis might be suppressed by the use of a centrifugal pump.

  13. Different Ways to On-Line Hyphenate Centrifugal Partition Chromatography and Mass Spectrometry: Application to Prenylated Xanthones from Garcinia mangostana.

    Science.gov (United States)

    Destandau, Emilie; Michel, Thomas; Toribio, Alix; Elfakir, Claire

    2015-11-01

    Centrifugal partition chromatography is a liquid-liquid separation method well adapted for the fractionation or purification of natural compounds from plant extracts. However, following the preparative isolation, the fractions collected must be analysed by high-performance thin-layer chromatography or high-performance liquid chromatography to evaluate their composition and/or their purity. These additional steps are time-consuming and increase the risk of compound degradation. In order to get an instantaneous analysis of fraction content with structural information on the phytochemicals eluted, it is possible to hyphenate on-line centrifugal partition chromatography with mass spectrometry. Depending on the complexity of the extract, two different kinds of centrifugal partition chromatography-mass spectrometry coupling can be performed: centrifugal partition chromatography-mass spectrometry or centrifugal partition chromatography-high-performance liquid chromatography-mass spectrometry coupling. In the first case, one part of the centrifugal partition chromatography effluent is directly introduced in the mass spectrometry ionisation source to identify the eluted compounds, while in the second case, it is directed to a high-performance liquid chromatography-mass spectrometry system where compounds are first separated thanks to high-performance liquid chromatography and then identified using mass spectrometry.

  14. Different Ways to On-Line Hyphenate Centrifugal Partition Chromatography and Mass Spectrometry: Application to Prenylated Xanthones from Garcinia mangostana.

    Science.gov (United States)

    Destandau, Emilie; Michel, Thomas; Toribio, Alix; Elfakir, Claire

    2015-11-01

    Centrifugal partition chromatography is a liquid-liquid separation method well adapted for the fractionation or purification of natural compounds from plant extracts. However, following the preparative isolation, the fractions collected must be analysed by high-performance thin-layer chromatography or high-performance liquid chromatography to evaluate their composition and/or their purity. These additional steps are time-consuming and increase the risk of compound degradation. In order to get an instantaneous analysis of fraction content with structural information on the phytochemicals eluted, it is possible to hyphenate on-line centrifugal partition chromatography with mass spectrometry. Depending on the complexity of the extract, two different kinds of centrifugal partition chromatography-mass spectrometry coupling can be performed: centrifugal partition chromatography-mass spectrometry or centrifugal partition chromatography-high-performance liquid chromatography-mass spectrometry coupling. In the first case, one part of the centrifugal partition chromatography effluent is directly introduced in the mass spectrometry ionisation source to identify the eluted compounds, while in the second case, it is directed to a high-performance liquid chromatography-mass spectrometry system where compounds are first separated thanks to high-performance liquid chromatography and then identified using mass spectrometry. PMID:25615274

  15. Centrifugal acceleration in the magnetotail lobes

    Directory of Open Access Journals (Sweden)

    H. Nilsson

    2010-02-01

    Full Text Available Combined Cluster EFW and EDI measurements have shown that cold ion outflow in the magnetospheric lobes dominates the hydrogen ion outflow from the Earth's atmosphere. The ions have too low kinetic energy to be measurable with particle instruments, at least for the typical spacecraft potential of a sunlit spacecraft in the tenuous lobe plasmas outside a few RE. The measurement technique yields both density and bulk velocity, which can be combined with magnetic field measurements to estimate the centrifugal acceleration experienced by these particles. We present a quantitative estimate of the centrifugal acceleration, and the velocity change with distance which we would expect due to centrifugal acceleration. It is found that the centrifugal acceleration is on average outward with an average value of about of 5 m s−2. This is small, but acting during long transport times and over long distances the cumulative effect is significant, while still consistent with the relatively low velocities estimated using the combination of EFW and EDI data. The centrifugal acceleration should accelerate any oxygen ions in the lobes to energies observable by particle spectrometers. The data set also put constraints on the effectiveness of any other acceleration mechanisms acting in the lobes, where the total velocity increase between 5 and 19 RE geocentric distance is less than 5 km s−1.

  16. Centrifugal compressor design for electrically assisted boost

    Science.gov (United States)

    Y Yang, M.; Martinez-Botas, R. F.; Zhuge, W. L.; Qureshi, U.; Richards, B.

    2013-12-01

    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically.

  17. Centrifugal compressor design for electrically assisted boost

    International Nuclear Information System (INIS)

    Electrically assisted boost is a prominent method to solve the issues of transient lag in turbocharger and remains an optimized operation condition for a compressor due to decoupling from turbine. Usually a centrifugal compressor for gasoline engine boosting is operated at high rotational speed which is beyond the ability of an electric motor in market. In this paper a centrifugal compressor with rotational speed as 120k RPM and pressure ratio as 2.0 is specially developed for electrically assisted boost. A centrifugal compressor including the impeller, vaneless diffuser and the volute is designed by meanline method followed by 3D detailed design. Then CFD method is employed to predict as well as analyse the performance of the design compressor. The results show that the pressure ratio and efficiency at design point is 2.07 and 78% specifically

  18. Wave-Driven Rotation In Centrifugal Mirrors

    International Nuclear Information System (INIS)

    Centrifugal mirrors use supersonic rotation to provide axial confinement and enhanced stability. Usually the rotation is produced using electrodes, but these electrodes have limited the rotation to the Alfven critical ionization velocity, which is too slow to be useful for fusion. Instead, the rotation could be produced using radio frequency waves. A fixed azimuthal ripple is a simple and efficient wave that could produce rotation by harnessing alpha particle energy. This is an extension of the alpha channeling effect. The alpha particle power and efficiency in a simulated devices is sufficient to produce rotation without external energy input. By eliminating the need for electrodes, this opens new opportunities for centrifugal traps.

  19. Experiments on Plasma Injection into a Centrifugally Confined System

    Science.gov (United States)

    Messer, S.; Bomgardner, R.; Brockington, S.; Case, A.; Witherspoon, F. D.; Uzun-Kaymak, I.; Elton, R.; Young, W.; Teodorescu, C.; Morales, C. H.; Ellis, R. F.

    2009-11-01

    We describe the cross-field injection of plasma into a centrifugally-confined system. Two different types of plasma railgun have been installed on the Maryland Centrifugal Experiment (MCX) in an attempt to drive that plasma's rotation. The initial gun was a coaxial device designed to mitigate the blowby instability. The second one was a MiniRailgun with a rectangular bore oriented so that the MCX magnetic field augments the railgun's internal magnetic field. Tests at HyperV indicate this MiniRailgun reaches much higher densities than the original gun, although muzzle velocity is slightly reduced. We discuss the impact of these guns on MCX for various conditions. Initial results show that even for a 2 kG field, firing the MiniRailgun modifies oscillations of the MCX diamagnetic loops and can impact the core current and voltage. The gun also has a noticeable impact on MCX microwave emissions. These observations suggest plasma enters the MCX system. We also compare diagnostic data collected separately from MCX for these and other guns, focussing primarily on magnetic measurements.

  20. Thermal hydrodynamic analysis of a countercurrent gas centrifuge; Analise termo hidrodinamica de uma centrifuga a contracorrente

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Delvonei Alves de

    1999-07-01

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  1. SEPARATION OF X-BEARING BOVINE SPERM BY CENTRIFUGATION IN CONTINUOUS PERCOLL AND OPTIPREP DENSITY GRADIENT: EFFECT IN SPERM VIABILITY AND IN VITRO EMBRYO PRODUCTION SEPARAÇÃO DE ESPERMATOZOIDES PORTADORES DO CROMOSSOMO X BOVINO POR CENTRIFUGAÇÃO EM GRADIENTE DE DENSIDADE CONTÍNUO DE PERCOLL E OPTIPREP: EFEITO SOBRE A VIABILIDADE ESPERMÁTICA E NA PRODUÇÃO IN VITRO DE EMBRIÕES

    Directory of Open Access Journals (Sweden)

    Aline Costa Lucio

    2009-07-01

    Full Text Available

    The aim of this study was to separate X-bearing bovine sperm by continuous Percoll and OptiPrep density gradients and to validate the sexing of resultant in vitro produced embryos by Polimerase Chain Reaction (PCR. Frozen/thawed sperm was layered on density gradients which were previously prepared in polystyrene tubes, 24 h before procedures and maintained at 4 °C. The tubes were centrifuged at 500 x g for 15 min at 22 °C. Supernatants were gently aspirated and the sperm recovered from the bottom of the tubes. Viability and integrity of sperm were evaluated by Trypan Blue/Giemsa stain. Cleavage and blastocyst rates were determined by in vitro production of embryos and PCR was performed for identification of the embryos’ genetic sex. No damage in viability and acrossomal integrity and in cleavage and blastocyst rates was found in the Percoll and OptiPrep treatment compared to the non-centrifuged group (P>0.05. The percentage of female embryos in the Percoll and OptiPrep group was 63.0 and 47.6%, respectively. The female embryos in control group were 48.7%. A sexual deviation in the Percoll density gradient was achieved without reduction of sperm viability and in vitro production rates.

    KEY WORDS: Bovine, centrifugation, in vitro production of embryos, PCR, X-bearing sperm.

    O objetivo deste estudo foi separar espermatozoides bovinos portadores do cromossomo X pela centrifugação em gradiente de densidade contínuo de Percoll e OptiPrep, e validar a sexagem pela reação em cadeia da polimerase (PCR, dos embriões produzidos in vitro. Para a sexagem, espermatozoides descongelados foram depositados nos gradientes de densidade, previamente preparados, em tubos de poliestireno, 24 horas antes da sexagem e mantidos a 4°C. Centrifugou-se a 500 x g por quinze minutos a 22°C. Os sobrenadantes foram aspirados, e os espermatozoides recuperados do

  2. Design Optimization of Centrifugal Pump Using Radial Basis Function Metamodels

    OpenAIRE

    Yu Zhang; Jinglai Wu; Yunqing Zhang; Liping Chen

    2014-01-01

    Optimization design of centrifugal pump is a typical multiobjective optimization (MOO) problem. This paper presents an MOO design of centrifugal pump with five decision variables and three objective functions, and a set of centrifugal pumps with various impeller shroud shapes are studied by CFD numerical simulations. The important performance indexes for centrifugal pump such as head, efficiency, and required net positive suction head (NPSHr) are investigated, and the results indicate that th...

  3. APPLICATION ANALYSIS REPORT: RETECH PLASMA CENTRIFUGAL FURNACE

    Science.gov (United States)

    This document is an evaluation of the performance of the Retech, Inc. Plasma Centrifugal Furnace (PCF) and its applicability as a treatment for soils contaminated with organic and/or inorganic compounds. Both the technical and economic aspectsof the technology were examined. A...

  4. Centrifugal Pump Experiment for Chemical Engineering Undergraduates

    Science.gov (United States)

    Vanderslice, Nicholas; Oberto, Richard; Marrero, Thomas R.

    2012-01-01

    The purpose of this paper is to describe a Centrifugal Pump Experiment that provided an experiential learning experience to chemical engineering undergraduates at the University of Missouri in the spring of 2010 in the Unit Operations Laboratory course. Lab equipment was used by senior students with computer-based data and control technology. In…

  5. Performance of a Centrifugal Slurry Pump

    Directory of Open Access Journals (Sweden)

    Hawas Yahya Bajawi

    2014-02-01

    Full Text Available The aim of this study was to experimentally investigate the effect of speed, concentration and size of slurry on the performance of a centrifugal pump. For this purpose a facility was built where the performance of a centrifugal slurry pump was examined using aggregate slurry. Three sizes of slurry with three concentrations and at three impeller speeds were used for the performance investigations of a centrifugal slurry pump. As a reference performance the performance of centrifugal slurry pump was also tested with clean water. The performance of pump has been reported as variations of head, power and efficiency at various flow rates along with the system characteristics of the pump. The results reveal that the pump performance is grossly affected by the type of slurry, its concentration and size. Besides this the variation in speed also affects the performance as is observed in pumps with water. The maximum decrease in the head, with respect to clear water, at the operating point was found to be 47% for aggregate for size 20 mm, 15% concentration and 2600 rpm. The maximum decrement in efficiency at operating point for aggregate was found to be 47% for 4 mm size, 15% concentration and at 2200 rpm. The power increment requirement for aggregate was 9% for 4 mm size, 15% concentration and 2600 rpm.

  6. Positive feedback stabilization of centrifugal compressor surge

    NARCIS (Netherlands)

    Willems, Frank; Heemels, W.P.M.H.; Jager, de Bram; Stoorvogel, Anton A.

    2002-01-01

    Stable operation of axial and centrifugal compressors is limited towards low mass flows due to the occurrence of surge. The stable operating region can be enlarged by active control. In this study, we use a control valve which is fully closed in the desired operating point and only opens to stabiliz

  7. Flow Pattern Characterization for a Centrifugal Impeller

    Science.gov (United States)

    Benavides, Efrén M.

    2014-08-01

    This paper proposes a model for characterizing the flow pattern of a centrifugal impeller attending to the severity of the reverse flow. The model assumes 1) a definition of an escaping particle as the one that flows in every operational point from the trailing edge towards the leading edge of the impeller blades, and 2) a characterization of flow where an operational point is said to have a theoretical flow pattern if it is not possible to establish a fully-reversed escaping particle on it. Therefore, the first part of the article is focused on defining an escaping particle for a centrifugal compressor. The model locates over the map of a centrifugal impeller the line that splits the map in two regions: the region on the right hand side, where a theoretical flow pattern can exist, and the region on the left, where a theoretical flow pattern cannot exist. Therefore, the locus of this line marks a frontier where the expected performance of the impeller cannot be sustained as high as expected. The second part of the article uses a high-performance commercial centrifugal impeller wheel for contrasting the model. A qualitative characterization of the surge line, conclusions and discussions are presented.

  8. Centrifugal Sieve for Gravity-Level-Independent Size Segregation of Granular Materials

    Science.gov (United States)

    Walton, Otis R.; Dreyer, Christopher; Riedel, Edward

    2013-01-01

    Conventional size segregation or screening in batch mode, using stacked vibrated screens, is often a time-consuming process. Utilization of centrifugal force instead of gravity as the primary body force can significantly shorten the time to segregate feedstock into a set of different-sized fractions. Likewise, under reduced gravity or microgravity, a centrifugal sieve system would function as well as it does terrestrially. When vibratory and mechanical blade sieving screens designed for terrestrial conditions were tested under lunar gravity conditions, they did not function well. The centrifugal sieving design of this technology overcomes the issues that prevented sieves designed for terrestrial conditions from functioning under reduced gravity. These sieves feature a rotating outer (cylindrical or conical) screen wall, rotating fast enough for the centrifugal forces near the wall to hold granular material against the rotating screen. Conventional centrifugal sieves have a stationary screen and rapidly rotating blades that shear the granular solid near the stationary screen, and effect the sieving process assisted by the airflow inside the unit. The centrifugal sieves of this new design may (or may not) have an inner blade or blades, moving relative to the rotating wall screen. Some continuous flow embodiments would have no inner auger or blades, but achieve axial motion through vibration. In all cases, the shearing action is gentler than conventional centrifugal sieves, which have very high velocity differences between the stationary outer screen and the rapidly rotating blades. The new design does not depend on airflow in the sieving unit, so it will function just as well in vacuum as in air. One advantage of the innovation for batch sieving is that a batch-mode centrifugal sieve may accomplish the same sieving operation in much less time than a conventional stacked set of vibrated screens (which utilize gravity as the primary driving force for size separation

  9. 14 CFR 35.35 - Centrifugal load tests.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Centrifugal load tests. 35.35 Section 35.35... STANDARDS: PROPELLERS Tests and Inspections § 35.35 Centrifugal load tests. The applicant must demonstrate... to twice the maximum centrifugal load to which the propeller would be subjected during operation...

  10. Bacterial Cell Surface Damage Due to Centrifugal Compaction

    NARCIS (Netherlands)

    Peterson, Brandon W.; Sharma, Prashant K.; van der Mei, Henny C.; Busscher, Henk J.

    2012-01-01

    Centrifugal damage has been known to alter bacterial cell surface properties and interior structures, including DNA. Very few studies exist on bacterial damage caused by centrifugation because of the difficulty in relating centrifugation speed and container geometry to the damage caused. Here, we pr

  11. A Parametric Study for High-Efficiency Gas-Liquid Separator Design

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A gas liquid centrifugal separator is widely used in industry on account of its simple geometry and little maintenance. These separators have considerable advantages over filters, scrubbers or precipitators in term of compact design, lower pressure drop and higher capacity. A gas liquid centrifugal separator is a device that utilizes centrifugal forces and low pressure caused by rotational motion to separate liquid from gas by density differences.Efficient and reliable separation is required for the optimum operation. These separators axe often operated at less than peak efficiency due to the entrainment of separated liquid through an outlet pipe which is closely associated with the very complicated flow phenomena involved. Design parameters such as length of the separation space,vane exit angle, inlet to outlet diameter ratio, models for separation efficiency and pressure drop as a function of physical dimensions are not available in literature. This leaves the designer with very little to go on except known designs and experimentation. The aim of present study is to perform a parametric study to get higher efficiency for gas-liquid separator. A parametric study has been carried out with the help of CFD tools to analyze a separation performance of a centrifugal separator by varying the length of separator space. The best design parameters are analyzed based upon obtained results, tangential velocities, vortices, total pressure losses. From the present study several attempts are made to improve the performance of conventional centrifugal separators.

  12. Prediction and verification of centrifugal dewatering of P. pastoris fermentation cultures using an ultra scale-down approach.

    Science.gov (United States)

    Lopes, A G; Keshavarz-Moore, E

    2012-08-01

    Recent years have seen a dramatic rise in fermentation broth cell densities and a shift to extracellular product expression in microbial cells. As a result, dewatering characteristics during cell separation is of importance, as any liquor trapped in the sediment results in loss of product, and thus a decrease in product recovery. In this study, an ultra scale-down (USD) approach was developed to enable the rapid assessment of dewatering performance of pilot-scale centrifuges with intermittent solids discharge. The results were then verified at scale for two types of pilot-scale centrifuges: a tubular bowl equipment and a disk-stack centrifuge. Initial experiments showed that employing a laboratory-scale centrifugal mimic based on using a comparable feed concentration to that of the pilot-scale centrifuge, does not successfully predict the dewatering performance at scale (P-value dewatering levels was achieved using the USD method (P-value ≥0.05), based on using a feed concentration at small-scale that mimicked the same height of solids as that in the pilot-scale centrifuge. Initial experiments used Baker's yeast feed suspensions followed by fresh Pichia pastoris fermentation cultures. This work presents a simple and novel USD approach to predict dewatering levels in two types of pilot-scale centrifuges using small quantities of feedstock (<50 mL). It is a useful tool to determine optimal conditions under which the pilot-scale centrifuge needs to be operated, reducing the need for repeated pilot-scale runs during early stages of process development.

  13. Isolation of antifungal and larvicidal constituents of Diplolophium buchanani by centrifugal partition chromatography.

    Science.gov (United States)

    Marston, A; Hostettmann, K; Msonthi, J D

    1995-01-01

    Three phenylpropanoids, myristicin [1], elemicin [2], and trans-isoelemicin [3], together with two furanocoumarins, oxypeucedanin [4] and oxypeucedanin hydrate [5], have been isolated from the leaves of Diplolophium buchanani by a separation strategy involving the almost exclusive use of centrifugal partition chromatography. All five compounds were antifungal in a tlc bioautography test using Cladosporium cucumerinum. Compounds 1-4 exhibited larvicidal activity against Aedes aegypti. PMID:7760070

  14. Comparison of flow characteristics of centrifugal compressors by numerical modelling of flow

    OpenAIRE

    Guzović, Zvonimir; Baburić, Mario; Matijašević, Dubravko

    2015-01-01

    The centrifugal impellers are used in a wide variety of turbo-machineries, ranging from low pressure fans for cooling of electric motor to high pressure ratio gas turbine compressors, from tiny cryo-cooler compressors to large industrial petrochemical compressor stations. The relative flow in centrifugalimpeller is very complex due to different fluid dynamics phenomenonand their interactions. It is subjected to the complex secondary flows and significant separation of the boundary layers, whi...

  15. A study of ceramic-lined composite steel pipes prepared by SHS centrifugal-thermite process

    OpenAIRE

    Li Yuxin; Jiang Letao; Lu Qing; Bai Peikang; Liu Bin; Wang Jianhong

    2016-01-01

    Al2O3 ceramic-lined steel pipe was produced by self-propagating high-temperature synthesis centrifugal thermite process (SHS C-T process) from Fe2O3 and Al as the raw materials. The composition, phase separation and microstructures were investigated. The result showed the ceramic lined pipe is composed of the three main layers of various compositions, which were subsequently determined to be Fe layer, the transition layer and the ceramic layer. Fe layer is ...

  16. Solanidine isolation from Solanum tuberosum by centrifugal partition chromatography.

    Science.gov (United States)

    Attoumbré, Jacques; Giordanengo, Philippe; Baltora-Rosset, Sylvie

    2013-07-01

    The aim of this investigation was the preparative isolation of solanidine (aglycone of the two main potato glycoalkaloids: α-chaconine and α-solanine) from fresh Solanum tuberosum (cv. Pompadour) material by implementing a new preparation scheme using centrifugal partition chromatography (CPC). A setup for obtaining solanidine by hydrolysis of the glycoalkaloids found in the skin and sprouts of S. tuberosum was first developed. Then its isolation was carried out by the development of CPC conditions: the solvent system used for separation was ethyl acetate/butanol/water in the ratio 42.5:7.5:50 v/v/v, 0.6 g of crude extract were separated with a 8 mL/min flow rate of mobile phase while rotating at 2500 rpm. A run yielded 98 mg of solanidine (86.7% recovery from the crude extract) in a one-step separation. The purity of the isolated solanidine was over 98%. Thus, CPC has proven to be the method of choice to get solanidine of very high purity from S. tuberosum biomass in large quantities.

  17. A specter of coexistence: Is centrifugal community organization haunted by the ghost of competition?

    Science.gov (United States)

    Wasserberg, G.; Kotler, B.P.; Morris, D.W.; Abramsky, Z.

    2006-01-01

    In a centrifugally organized community species prefer the same habitat (called "core") but differ in their secondary habitat preferences. The first model of centrifugal community organization (CCO) predicted that optimally foraging, symmetrically competing species would share use of the core habitat at all density combinations. But one might also assume that the competition in the core habitat is asymmetrical, that is, that one of the species (the dominant) has a behavioral advantage therein. In this study, we asked how should habitat use evolve in a centrifugally organized community if its species compete asymmetrically in the core habitat? To address this question we developed an "isoleg model". The model predicts that in a centrifugally organized community, asymmetric competition promotes the use of the core habitat exclusively by the dominant species at most points in the state space. The separation of the core habitat use by the species ("the ghost of competition past") may be either complete or partial ("partial ghost"), and behavior at the stable competitive equilibrium between the species could determine whether coexistence should occur at the "complete-" or the "partial ghost" regions. This version of CCO should be a common feature of competitive systems.

  18. A vibration model for centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, R.A.; Wasserman, M.O.; Wygmans, D.G.

    1992-11-01

    Using the transfer matrix method, we created the Excel worksheet ``Beam`` for analyzing vibrations in centrifugal contactors. With this worksheet, a user can calculate the first natural frequency of the motor/rotor system for a centrifugal contactor. We determined a typical value for the bearing stiffness (k{sub B}) of a motor after measuring the k{sub B} value for three different motors. The k{sub B} value is an important parameter in this model, but it is not normally available for motors. The assumptions that we made in creating the Beam worksheet were verified by comparing the calculated results with those from a VAX computer program, BEAM IV. The Beam worksheet was applied to several contactor designs for which we have experimental data and found to work well.

  19. Meridional Considerations of the Centrifugal Compressor Development

    Directory of Open Access Journals (Sweden)

    C. Xu

    2012-01-01

    Full Text Available Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some recent studies of meridional impacts of the compressor. Studies indicated that the meridional profiles of the impeller impact the overall compressor efficiency and pressure ratio at the same rotational speed. Proper meridional profiles can improve the compressor efficiency and increase the overall pressure ratio at the same blade back curvature.

  20. High stability design for new centrifugal compressor

    Science.gov (United States)

    Kanki, H.; Katayama, K.; Morii, S.; Mouri, Y.; Umemura, S.; Ozawa, U.; Oda, T.

    1989-01-01

    It is essential that high-performance centrifugal compressors be free of subsynchronous vibrations. A new high-performance centrifugal compressor has been developed by applying the latest rotordynamics knowledge and design techniques: (1) To improve the system damping, a specially designed oil film seal was developed. This seal attained a damping ratio three times that of the conventional design. The oil film seal contains a special damper ring in the seal cartridge. (2) To reduce the destabilizing effect of the labyrinth seal, a special swirl canceler (anti-swirl nozzle) was applied to the balance piston seal. (3) To confirm the system damping margin, the dynamic simulation rotor model test and the full load test applied the vibration exciting test in actual load conditions.

  1. Vibration analysis of large centrifugal pump rotors

    Science.gov (United States)

    Y Zhao, W.; Ge, J. G.; Ma, D.; Li, C. M.; Bao, S. B.

    2013-12-01

    Through the critical speed of centrifugal pumps, internal flow field and the force of the impeller, we analyze centrifugal pump vibration. Using finite element analysis software ANSYS to calculate the natural frequency of the rotor system and the critical speed; with the help of the Fluent software to simulate pump internal flow field, we conclude that speed increase will not cause intense vibration of the fluid in the pump. Using unsteady numerical simulation we discovered that in an impeller suffering transient radial force cyclical change periodically, as well as the frequency size determined by the product of the impeller speed and number of blades, resonance phenomena should make impeller to transient radial force frequency. If wanting to avoid pump resonance when it is running away, the transient radial force frequency should avoid the frequency range which can cause resonance.

  2. Vibration analysis of large centrifugal pump rotors

    International Nuclear Information System (INIS)

    Through the critical speed of centrifugal pumps, internal flow field and the force of the impeller, we analyze centrifugal pump vibration. Using finite element analysis software ANSYS to calculate the natural frequency of the rotor system and the critical speed; with the help of the Fluent software to simulate pump internal flow field, we conclude that speed increase will not cause intense vibration of the fluid in the pump. Using unsteady numerical simulation we discovered that in an impeller suffering transient radial force cyclical change periodically, as well as the frequency size determined by the product of the impeller speed and number of blades, resonance phenomena should make impeller to transient radial force frequency. If wanting to avoid pump resonance when it is running away, the transient radial force frequency should avoid the frequency range which can cause resonance

  3. Condensing Heat Recovery of Centrifugal Chiller

    Institute of Scientific and Technical Information of China (English)

    GONG Guang-cai; JIAO Jun-jun; WANG Li-ping; ZENG Wei

    2009-01-01

    To a kind of centrifugal water chiUer with R22 and about 1745 kW of cooling capacity.a heat exchanger was added between the outlet of compressor and original condenser to get part of or all the condensing heat.Condensing heat can be recovered by compound condensing method,which adopts air-cooling model+wa-ter-cooling model or water-cooling model+water-cooling model at the condensing side of the system.By exergy analysis and experiment research on compound condensing heat recovery of centrifugal chiller,the results are ob-tained that the capability of the whole system increases,the energy efficiency ratio (EER) becomes 3.2~5.0 from 2.2~3.4, which implies the EER increases about 1.0~1.5,the exergy efficiency increases about 10%,and the chiller runs more stably after reformation.

  4. Centrifuge modeling of soil atmosphere interaction

    OpenAIRE

    CAICEDO, B; TRISTANCHO, J; THOREL, Luc

    2010-01-01

    Atmosphere process of infiltration or evaporation affect the behavior of geotechnical structures located near the soil surface. This paper focuses on the drying process of soils due to evaporation. The scaling laws are analyzed and afterwards the results on applying two cycles of heating and cooling on a soil mass are presented. Based on these results, conclusions about the feasibility of reproducing evaporation on centrifuge models are recommended.

  5. Centrifugal shot blasting. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    1999-07-01

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer.

  6. Aerodynamic instabilities in transonic centrifugal compressor

    OpenAIRE

    Buffaz, Nicolas; Trébinjac, Isabelle

    2014-01-01

    International audience This paper presents the analysis of the instabilities inception in a transonic centrifugal com-pressor for different rotation speeds. The analysis was conducted from experimental results obtained with unsteady pressure sensors implanted in the inducer, vaneless diffuser and vaned diffuser. Beyond the stability limit the compressor enters into a deep surge without any precursor, whatever the speed. The surge process is initiated in the vaned diffuser by a massive boun...

  7. Submarine landslide flows simulation through centrifuge modelling

    OpenAIRE

    Gue, Chang Shin

    2012-01-01

    Landslides occur both onshore and offshore. However, little attention has been given to offshore landslides (submarine landslides). Submarine landslides have significant impacts and consequences on offshore and coastal facilities. The unique characteristics of submarine landslides include large mass movements and long travel distances at very gentle slopes. This thesis is concerned with developing centrifuge scaling laws for submarine landslide flows through the study of modell...

  8. Development of centrifuge modelling in geotechnics

    OpenAIRE

    J. Garnier

    2006-01-01

    In order to satisfy similitude conditions, physical modelling in the field of geotechnics requires major facilities, such as shaking tables, calibration chambers and centrifuges. The rapid expansion of centifuge modelling since the beginning of the 1980's can be explained by technological developments in computing, electronics and mechanics as well by enhanced knowledge in the areas of scaling laws, thanks to recent research work on both the properties of reconstituted soils and similitude co...

  9. Centrifugal shot blasting. Innovative technology summary report

    International Nuclear Information System (INIS)

    At the US Department of Energy (DOE) Fernald Environmental Management Project (FEMP), the Facilities Closure and Demolition Projects Integrated Remedial Design/Remedial Action (RD/RA) work plan calls for the removal of one inch (1 in) depth of concrete surface in areas where contamination with technetium-99 has been identified. This report describes a comparative demonstration between two concrete removal technologies: an innovative system using Centrifugal Shot Blasting (CSB) and a modified baseline technology called a rotary drum planer

  10. Potential flow through centrifugal pumps and turbines

    Science.gov (United States)

    Sorensen, E

    1941-01-01

    The methods of conformal transformation up to the present have been applied to the potential flows in the rotation of solid bodies only to a limited extent. This report deals with aspects of centrifugal pumps and turbines such as: the complex potential for rotation, potential for the flow due to the blade rotation, velocities at the blade tip, comparison with "infinite number of blades," and a variable number of blades.

  11. CENTRIFUGAL VIBRATION TEST OF RC PILE FOUNDATION

    Science.gov (United States)

    Higuchi, Shunichi; Tsutsumiuchi, Takahiro; Otsuka, Rinna; Ito, Koji; Ejiri, Joji

    It is necessary that nonlinear responses of structures are clarified by soil-structure interaction analysis for the purpose of evaluating the seismic performances of underground structure or foundation structure. In this research, centrifuge shake table tests of reinforced concrete pile foundation installed in the liquefied ground were conducted. Then, finite element analyses for the tests were conducted to confirm an applicability of the analytical method by comparing the experimental results and analytical results.

  12. Centrifugal compressor design choices for chillers

    Energy Technology Data Exchange (ETDEWEB)

    Brasz, J.J. [United Technologies Carrier, New York, NY (United States)

    1999-07-01

    The use of centrifugal compressors in the air conditioning and refrigeration industry is currently limited to large water cooled chillers varying in size from about 0.5 to 6 MW cooling capacity. These systems are primarily used for comfort or process cooling applications. All systems try to chill relatively large amounts of indoor or process water by a few degrees Celsius in a refrigerant evaporator. The heat removed from the chilled water is released together with the heat of compression in a refrigerant condenser to cooling tower water, from where it is discharged to the atmosphere. Different centrifugal compressor design concepts are used by the various chiller manufacturers: single-stage versus multi-stage, vaneless versus vaned diffuser, hermetic versus open-drive motors, shrouded versus open impellers, fixed versus variable diffuser geometry, low- versus high-pressure refrigerant. This variability seems strange for a mature industry like the air conditioning and refrigeration industry. This paper will show that the reason for this variability is the product compromise between the various conflicting system requirements with respect to size, cost, efficiency and refrigerant choice. The different system applications of the chillers (e.g. comfort cooling in a equatorial region versus process cooling in a moderate climate zone) play another major role in selecting an optimal centrifugal compression concept. Some general recommendations will be given for applications where a clear choice can be made. (Author)

  13. Compact, Automated Centrifugal Slide-Staining System

    Science.gov (United States)

    Feeback, Daniel L.; Clarke, Mark S. F.

    2004-01-01

    The Directional Acceleration Vector-Driven Displacement of Fluids (DAVD-DOF) system, under development at the time of reporting the information for this article, would be a relatively compact, automated, centrifugally actuated system for staining blood smears and other microbiological samples on glass microscope slides in either a microgravitational or a normal Earth gravitational environment. The DAVD-DOF concept is a successor to the centrifuge-operated slide stainer (COSS) concept, which was reported in Slide-Staining System for Microgravity or Gravity (MSC-22949), NASA Tech Briefs, Vol. 25, No. 1 (January, 2001), page 64. The COSS includes reservoirs and a staining chamber that contains a microscope slide to which a biological sample is affixed. The staining chamber is sequentially filled with and drained of staining and related liquids from the reservoirs by use of a weighted plunger to force liquid from one reservoir to another at a constant level of hypergravity maintained in a standard swing-bucket centrifuge. In the DAVD-DOF system, a staining chamber containing a sample would also be sequentially filled and emptied, but with important differences. Instead of a simple microscope slide, one would use a special microscope slide on which would be fabricated a network of very small reservoirs and narrow channels connected to a staining chamber (see figure). Unlike in the COSS, displacement of liquid would be effected by use of the weight of the liquid itself, rather than the weight of a plunger.

  14. Shallow water model for horizontal centrifugal casting

    Science.gov (United States)

    Boháček, J.; Kharicha, A.; Ludwig, A.; Wu, M.

    2012-07-01

    A numerical model was proposed to simulate the solidification process of an outer shell of work roll made by the horizontal centrifugal casting technique. Shallow water model was adopted to solve the 2D average flow dynamics of melt spreading and the average temperature distribution inside the centrifugal casting mould by considering the centrifugal force, Coriolis force, viscous force due to zero velocity on the mould wall, gravity, and energy transport by the flow. Additionally, a 1D sub-model was implemented to consider the heat transfer in the radial direction from the solidifying shell to the mould. The solidification front was tracked by fulfilling the Stefan condition. Radiative and convective heat losses were included from both, the free liquid surface and the outer wall of the mould. Several cases were simulated with the following assumed initial conditions: constant height of the liquid metal (10, 20, and 30 mm), uniform temperature of the free liquid surface (1755 K). The simulation results have shown that while the solidification front remained rather flat, the free surface was disturbed by waves. The amplitude of waves increased with the liquid height. Free surface waves diminished as the solidification proceeded.

  15. CFD Analysis of Centrifugal Pump: A Review

    Directory of Open Access Journals (Sweden)

    Narayan P. Jaiswal

    2014-05-01

    Full Text Available The main objective of this work is to understand role of the computational fluid dynamics (CFD technique in analyzing and predicting the performance of centrifugal pump. Computational Fluid Dynamics (CFD is the present day state-of-art technique for fluid flow analysis. The critical review of CFD analysis of CFD analysis of centrifugal pump along with future scope for further improvement is presented in this paper. Different solver like ANSYS-CFX, FLUENT etc can be used for simulations. Shear stress transport model has been found appropriate as turbulence model. Study of pressure contours, velocity contours, flow streamlines etc can be studied by CFD techniques. Unsteady Reynolds Averaged Navier Stokes (URANS equations are solved by solver to get flow simulation results inside centrifugal pump. CFD results has to be validated with testing results or with performance characteristics curves. Performance prediction at design and off-design conditions, parametric study, cavitation analysis, diffuser pump analysis, performance of pump running in turbine mode etc. are possible with CFD simulation techniques.

  16. Separation phenomena in Liquids and Gases

    Energy Technology Data Exchange (ETDEWEB)

    Louvet, P.; Dr Soubbaramayer [CEA Saclay, Dept. des Lasers et de la Physico-Chimie, DESICP/DLPC/SPP, 91 - Gif-sur-Yvette (France); Noe, P

    1989-07-01

    The Proceedings of the 1989 Workshop are presented in two volumes: volume 1 contains 4 papers on plasma processes and 7 papers on centrifugation. The papers on plasma processes deal with two main methods: ion cyclotron resonance and rotating plasmas. A survey lecture reviews extensively the physics of the two processes, the published experimental results and includes an abundant bibliography of about 200 references. The 3 other papers communicate original and recent experiments carried out by the authors. The plasma process remains as a possible technology to separate stable isotopes and isotopes of metals located in the middle of the Mendeleev Table. Regarding the stable isotopes, the ion cyclotron resonance might be an alternative to the Calutron process. The sessions on centrifugation include 2 review papers by URENCO authors and 5 specialized communications. The review papers take stock of the centrifuge research and gives the current status of the centrifuge technology in URENCO. The authors say that the centrifugation is presently an established industrial and commercial process ready to enter in competition for any new construction of enrichment capacity. Volume 2 contains the papers on 3 topics: basic studies (11 papers), chemical process (2 papers) and laser processes (7 papers). The papers on basic studies include investigations on rotating flows. A special attention is given to studies on convection flows, driven by acceleration field or (and) capillary forces. The interest of convection is obvious, as it has applications in important fields: the hydrodynamics of liquid uranium in the evaporation crucible of AVLIS Process, the crystal growth experiments on earth or under microgravity conditions (future experiments planned in space-labs) and the welding by electron or photon beams. Two papers are presented on the chemical process and both of them are by French authors. The French CEA has, in the past, developed with success the CHEMEX process. The

  17. Separation phenomena in Liquids and Gases

    International Nuclear Information System (INIS)

    The Proceedings of the 1989 Workshop are presented in two volumes: volume 1 contains 4 papers on plasma processes and 7 papers on centrifugation. The papers on plasma processes deal with two main methods: ion cyclotron resonance and rotating plasmas. A survey lecture reviews extensively the physics of the two processes, the published experimental results and includes an abundant bibliography of about 200 references. The 3 other papers communicate original and recent experiments carried out by the authors. The plasma process remains as a possible technology to separate stable isotopes and isotopes of metals located in the middle of the Mendeleev Table. Regarding the stable isotopes, the ion cyclotron resonance might be an alternative to the Calutron process. The sessions on centrifugation include 2 review papers by URENCO authors and 5 specialized communications. The review papers take stock of the centrifuge research and gives the current status of the centrifuge technology in URENCO. The authors say that the centrifugation is presently an established industrial and commercial process ready to enter in competition for any new construction of enrichment capacity. Volume 2 contains the papers on 3 topics: basic studies (11 papers), chemical process (2 papers) and laser processes (7 papers). The papers on basic studies include investigations on rotating flows. A special attention is given to studies on convection flows, driven by acceleration field or (and) capillary forces. The interest of convection is obvious, as it has applications in important fields: the hydrodynamics of liquid uranium in the evaporation crucible of AVLIS Process, the crystal growth experiments on earth or under microgravity conditions (future experiments planned in space-labs) and the welding by electron or photon beams. Two papers are presented on the chemical process and both of them are by French authors. The French CEA has, in the past, developed with success the CHEMEX process. The

  18. High Technology Centrifugal Compressor for Commercial Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ruckes, John

    2006-04-15

    R&D Dynamics, Bloomfield, CT in partnership with the State of Connecticut has been developing a high technology, oil-free, energy-efficient centrifugal compressor called CENVA for commercial air conditioning systems under a program funded by the US Department of Energy. The CENVA compressor applies the foil bearing technology used in all modern aircraft, civil and military, air conditioning systems. The CENVA compressor will enhance the efficiency of water and air cooled chillers, packaged roof top units, and other air conditioning systems by providing an 18% reduction in energy consumption in the unit capacity range of 25 to 350 tons of refrigeration The technical approach for CENVA involved the design and development of a high-speed, oil-free foil gas bearing-supported two-stage centrifugal compressor, CENVA encompassed the following high technologies, which are not currently utilized in commercial air conditioning systems: Foil gas bearings operating in HFC-134a; Efficient centrifugal impellers and diffusers; High speed motors and drives; and System integration of above technologies. Extensive design, development and testing efforts were carried out. Significant accomplishments achieved under this program are: (1) A total of 26 builds and over 200 tests were successfully completed with successively improved designs; (2) Use of foil gas bearings in refrigerant R134a was successfully proven; (3) A high speed, high power permanent magnet motor was developed; (4) An encoder was used for signal feedback between motor and controller. Due to temperature limitations of the encoder, the compressor could not operate at higher speed and in turn at higher pressure. In order to alleviate this problem a unique sensorless controller was developed; (5) This controller has successfully been tested as stand alone; however, it has not yet been integrated and tested as a system; (6) The compressor successfully operated at water cooled condensing temperatures Due to temperature

  19. Short communication: Improved method for centrifugal recovery of bacteria from raw milk applied to sensitive real-time quantitative PCR detection of Salmonella spp

    Science.gov (United States)

    Centrifugation of milk is widely used as a separation/concentration step in assays for pathogenic microorganisms. Separation of the cream and liquid supernate from the pellet containing sedimented solids, somatic cells and microorganisms eliminates many interfering substances, and resuspension of th...

  20. Unsteady behavior and control of vortices in centrifugal compressor

    Science.gov (United States)

    Ohta, Yutaka; Fujisawa, Nobumichi

    2014-10-01

    Two examples of the use of vortex control to reduce noise and enhance the stable operating range of a centrifugal compressor are presented in this paper. In the case of high-flow operation of a centrifugal compressor with a vaned diffuser, a discrete frequency noise induced by interaction between the impeller-discharge flow and the diffuser vane, which appears most notably in the power spectra of the radiated noise, can be reduced using a tapered diffuser vane (TDV) without affecting the performance of the compressor. Twin longitudinal vortices produced by leakage flow passing through the tapered portion of the diffuser vane induce secondary flow in the direction of the blade surface and prevent flow separation from the leading edge of the diffuser. The use of a TDV can effectively reduce both the discrete frequency noise generated by the interaction between the impeller-discharge flow and the diffuser surface and the broadband turbulent noise component. In the case of low-flow operation, a leading-edge vortex (LEV) that forms on the shroud side of the suction surface near the leading edge of the diffuser increases significantly in size and blocks flow in the diffuser passage. The formation of an LEV may adversely affect the performance of the compressor and may cause the diffuser to stall. Using a one-side tapered diffuser vane to suppress the evolution of an LEV, the stable operating range of the compressor can be increased by more than 12 percent, and the pressure-rise characteristics of the compressor can be improved. The results of a supplementary examination of the structure and unsteady behavior of LEVs, conducted by means of detailed numerical simulations, are also presented.

  1. ELECTRO-HYDRAULIC SERVO SYSTEM IN THE CENTRIFUGE FIELD

    Institute of Scientific and Technical Information of China (English)

    Dong Longlei; Yan Guirong; Li Ronglin

    2004-01-01

    The mechanical characteristics of the electro-hydraulic servo system in the centrifuge field are analyzed.The hydraulic pressure law in the centrifuge field indicates the existence of the centrifuge hydraulic pressure.The mechanical characteristics of the slide-valve and the dual nozzle flapper valve are studied,and it is found that the centrifuge field can not only increase the driving force or moment of the function units,but also decrease the stability of the components.Finally by applying Gauss minimum constraint principle,the dynamic model of the electro-hydraulic vibrator in the centrifuge field is established,and the mechanical restriction of the system is also presented.The study will be helpful for the realization of the combined vibration and centrifuge test system.

  2. Trajectory and terminal distribution of single centrifugal axons from olfactory cortical areas in the rat olfactory bulb.

    Science.gov (United States)

    Matsutani, S

    2010-08-11

    The olfactory bulb receives a large number of centrifugal fibers whose functions remain unclear. To gain insight into the function of the bulbar centrifugal system, the morphology of individual centrifugal axons from olfactory cortical areas was examined in detail. An anterograde tracer, Phaseolus vulgaris leucoagglutinin, was injected into rat olfactory cortical areas, including the pars lateralis of the anterior olfactory nucleus (lAON) and the anterior part of the piriform cortex (aPC). Reconstruction from serial sections revealed that the extrabulbar segments of centrifugal axons from the lAON and those from the aPC had distinct trajectories: the former tended to innervate the pars externa of the AON before entering the olfactory bulb, while the latter had extrabulbar collaterals that extended to a variety of targets. In contrast to the extrabulbar segments, no clear differences were found between the intrabulbar segments of axons from the lAON and from the aPC. The intrabulbar segments of centrifugal axons were mainly found in the granule cell layer but a few axons extended into the external plexiform and glomerular layer. Approximately 40% of centrifugal axons innervated both the medial and lateral aspects of the olfactory bulb. The number of boutons found on single intrabulbar segments was typically less than 1000. Boutons tended to aggregate and form complex terminal tufts with short axonal branches. Terminal tufts, no more than 10 in single axons from ipsilateral cortical areas, were localized to the granule cell layer with varying intervals; some tufts formed patchy clusters and others were scattered over areas that extended for a few millimeters. The patchy, widespread distribution of terminals suggests that the centrifugal axons are able to couple the activity of specific subsets of bulbar neurons even when the subsets are spatially separated.

  3. Evaluation of erythrocyte flow at a bearing gap in a hydrodynamically levitated centrifugal blood pump.

    Science.gov (United States)

    Murashige, Tomotaka; Kosaka, Ryo; Sakota, Daisuke; Nishida, Masahiro; Kawaguchi, Yasuo; Yamane, Takashi; Maruyama, Osamu

    2015-01-01

    We have developed a hydrodynamically levitated centrifugal blood pump for extracorporeal circulatory support. In the blood pump, a spiral groove bearing was adopted for a thrust bearing. In the spiral groove bearing, separation of erythrocytes and plasma by plasma skimming has been postulated to occur. However, it is not clarified that plasma skimming occurs in a spiral groove bearing. The purpose of this study is to verify whether plasma skimming occurs in the spiral groove bearing of a hydrodynamically levitated centrifugal blood pump. For evaluation of plasma skimming in the spiral groove bearing, an impeller levitation performance test using a laser focus displacement meter and a microscopic visualization test of erythrocyte flow using a high-speed microscope were conducted. Bovine blood diluted with autologous plasma to adjust hematocrit to 1.0% was used as a working fluid. Hematocrit on the ridge region in the spiral groove bearing was estimated using image analysis. As a result, hematocrits on the ridge region with gaps of 45 μm, 31 μm, and 25 μm were calculated as 1.0%, 0.6%, and 0.3%, respectively. Maximum skimming efficiency in this study was calculated as 70% with a gap of 25 μm. We confirmed that separation of erythrocyte and plasma occurred in the spiral groove bearing with decrease in bearing gap in a hydrodynamically levitated centrifugal blood pump.

  4. Centrifugal microfluidic platform for radiochemistry: potentialities for the chemical analysis of nuclear spent fuels.

    Science.gov (United States)

    Bruchet, Anthony; Taniga, Vélan; Descroix, Stéphanie; Malaquin, Laurent; Goutelard, Florence; Mariet, Clarisse

    2013-11-15

    The use of a centrifugal microfluidic platform is for the first time reported as an alternative to classical chromatographic procedures for radiochemistry. The original design of the microfluidic platform has been thought to fasten and simplify the prototyping process with the use of a circular platform integrating four rectangular microchips made of thermoplastic. The microchips, dedicated to anion-exchange chromatographic separations, integrate a localized monolithic stationary phase as well as injection and collection reservoirs. The results presented here were obtained with a simplified simulated nuclear spent fuel sample composed of non-radioactive isotopes of Europium and Uranium, in proportion usually found for uranium oxide nuclear spent fuel. While keeping the analytical results consistent with the conventional procedure (extraction yield for Europium of ≈97%), the use of the centrifugal microfluidic platform allowed to reduce the volume of liquid needed by a factor of ≈250. Thanks to their unique "easy-to-use" features, centrifugal microfluidic platforms are potential successful candidates for the downscaling of chromatographic separation of radioactive samples (automation, multiplexing, easy integration in glove-boxes environment and low cost of maintenance).

  5. Evaluation of erythrocyte flow at a bearing gap in a hydrodynamically levitated centrifugal blood pump.

    Science.gov (United States)

    Murashige, Tomotaka; Kosaka, Ryo; Sakota, Daisuke; Nishida, Masahiro; Kawaguchi, Yasuo; Yamane, Takashi; Maruyama, Osamu

    2015-01-01

    We have developed a hydrodynamically levitated centrifugal blood pump for extracorporeal circulatory support. In the blood pump, a spiral groove bearing was adopted for a thrust bearing. In the spiral groove bearing, separation of erythrocytes and plasma by plasma skimming has been postulated to occur. However, it is not clarified that plasma skimming occurs in a spiral groove bearing. The purpose of this study is to verify whether plasma skimming occurs in the spiral groove bearing of a hydrodynamically levitated centrifugal blood pump. For evaluation of plasma skimming in the spiral groove bearing, an impeller levitation performance test using a laser focus displacement meter and a microscopic visualization test of erythrocyte flow using a high-speed microscope were conducted. Bovine blood diluted with autologous plasma to adjust hematocrit to 1.0% was used as a working fluid. Hematocrit on the ridge region in the spiral groove bearing was estimated using image analysis. As a result, hematocrits on the ridge region with gaps of 45 μm, 31 μm, and 25 μm were calculated as 1.0%, 0.6%, and 0.3%, respectively. Maximum skimming efficiency in this study was calculated as 70% with a gap of 25 μm. We confirmed that separation of erythrocyte and plasma occurred in the spiral groove bearing with decrease in bearing gap in a hydrodynamically levitated centrifugal blood pump. PMID:26736252

  6. Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination

    OpenAIRE

    Hongkun Li; Xuefeng Zhang; Xiaowen Zhang; Shuhua Yang; Fujian Xu

    2014-01-01

    Blade is a key piece of component for centrifugal compressor. But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on. It could lead to blade failure and centrifugal compressor closing down. Therefore, it is important for blade crack early warning. It is difficult to determine blade crack as the information is weak. In this research, a pressure pulsation (PP) sensor installed in vicinity to the crack area is used to d...

  7. Numerical Investigations on the Transient Performance of a Centrifugal Pump

    OpenAIRE

    Asim, Taimoor; Mishra, Rakesh

    2015-01-01

    Centrifugal pumps are an integral part of plants used in process industries. The flow structure within a centrifugal pump is very complex due to the interaction between the rotating impeller and the geometric features around it. In the present study, numerical investigations on a centrifugal pump have been carried out using a Computational Fluid Dynamics (CFD) based solver. This study employs finite volume technique in order to analyse the influence of variations in the rotational speed of th...

  8. Latex Micro-balloon Pumping in Centrifugal Microfluidic Platforms

    OpenAIRE

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Al-Faqheri, Wisam; Thio, Tzer Hwai Gilbert; Kazemzadeh, Amin; Wadi harun, Sulaiman; Madou, Marc

    2014-01-01

    Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-stepped processes on a single microfluidics disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force. In this paper, a novel micro-balloon pumping method that relies on elastic energy stored in a...

  9. [Design and optimization of a centrifugal pump for CPCR].

    Science.gov (United States)

    Pei, J; Tan, X; Chen, K; Li, X

    2000-06-01

    Requirements for an optimal centrifugal pump, the vital component in the equipment for cardiopulmonary cerebral resuscitation(CPCR), have been presented. The performance of the Sarns centrifugal pump (Sarns, Inc./3M, Ann arbor, MI, U.S.A) was tested. The preliminarily optimized model for CPCR was designed according to the requirements of CPCR and to the comparison and analysis of several clinically available centrifugal pumps. The preliminary tests using the centrifugal pump made in our laboratory(Type CPCR-I) have confirmed the design and the optimization.

  10. Effects of centrifugation on gonadal and adrenocortical steroids in rats

    Science.gov (United States)

    Kakihana, R.; Butte, J. C.

    1980-01-01

    Many endocrine systems are sensitive to external changes in the environment. Both the pituitary adrenal and pituitary gonadal systems are affected by stress including centrifugation stress. The effect of centrifugation on the pituitary gonadal and pituitary adrenocortical systems was examined by measuring the gonadal and adrenal steroids in the plasma and brain following different duration and intensity of centrifugation stress in rats. Two studies were completed and the results are presented. The second study was carried out to describe the developmental changes of brain, plasma and testicular testosterone and dihydrotestosterone in Sprague Dawley rats so that the effect of centrifugation stress on the pituitary gonadal syatem could be better evaluated in future studies.

  11. Computer simulation for centrifugal mold filling of precision titanium castings

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Computer simulation codes were developed based on a proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings (CASM-3D for Windows). Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings under a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section precision castings.

  12. Characteristics of centrifugal rapid contactor, (3)

    International Nuclear Information System (INIS)

    Organic solvent yields the degradation product as a result of irradiation, in the extraction process of spent fuel reprocessing. The development of a centrifugal rapid contactor is required for the reduction of the solvent degradation by shortening the contact time. The effects of fine solid particles were investigated with a SGN-Robatel LX-208N contactor, following the uranium extraction and re-extraction performance tests. It was found as the experimental result that the considerable quantity of solids accumulated in the rotor of the centrifugal contactor. As for this experimental apparatus, the flow diagram for the centrifugal rapid contactor and auxiliary apparatuses is shown, which are the same system used for the uranium extraction and re-extraction tests. The schematic diagram, the typical stage construction and fluid transfer path of the LX-208 contactor are illustrated. The main specifications of the LX-208 contactor are as follows: the internal diameter of a rotating bowl 200 mm, the material SUS 316, the number of stages 8, and the total hold-up volume of the contactor 1.8 l. Most tests were carried out with aqueous feed only, because white Alundum is easily deposited in the rotor, and the particle concentration in effluent stream becomes undetectable when organic and aqueous feeds are supplied simultaneously. As the experimental results, the correlation of Alundum concentration in effluent and running time, the effect of rotor speed on effluent stream concentration, the particle size distribution curves for No. 6000 and No. 8000 white Alundum, the effect of flow rate on effluent stream concentration and the effect of flow rate on particle size distribution for both No. 6000 and No. 8000 white Alundum are presented. (Nakai, Y.)

  13. EM Task 9 - Centrifugal membrane filtration

    International Nuclear Information System (INIS)

    The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc)

  14. 2011 IEEE Visualization Contest Winner: Visualizing Unsteady Vortical Behavior of a Centrifugal Pump

    KAUST Repository

    Otto, Mathias

    2012-09-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump\\'s effectiveness. The winning entry split analysis of the pump into three parts based on the pump\\'s functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/ oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump. © 2012 IEEE.

  15. 2011 IEEE Visualization Contest winner: Visualizing unsteady vortical behavior of a centrifugal pump.

    Science.gov (United States)

    Otto, Mathias; Kuhn, Alexander; Engelke, Wito; Theisel, Holger

    2012-01-01

    In the 2011 IEEE Visualization Contest, the dataset represented a high-resolution simulation of a centrifugal pump operating below optimal speed. The goal was to find suitable visualization techniques to identify regions of rotating stall that impede the pump's effectiveness. The winning entry split analysis of the pump into three parts based on the pump's functional behavior. It then applied local and integration-based methods to communicate the unsteady flow behavior in different regions of the dataset. This research formed the basis for a comparison of common vortex extractors and more recent methods. In particular, integration-based methods (separation measures, accumulated scalar fields, particle path lines, and advection textures) are well suited to capture the complex time-dependent flow behavior. This video (http://youtu.be/oD7QuabY0oU) shows simulations of unsteady flow in a centrifugal pump.

  16. Improving the quality of graphene oxide prepared by Hummer's method by using centrifugation

    Science.gov (United States)

    Ardakani, Seyed Esmaeil Mahdavi; Singh, Balbir Singh Mahinder; Mohammed, Norani Muti

    2015-07-01

    Hummer's method is one of the most popular methods for preparing graphene oxide. This method requires fewer hazardous materials and is carried out at lower temperatures. The graphene oxide sheets prepared by this approach, contains various functional groups such as epoxide and hydroxyl. The oxidation of graphite by powerful oxidants used in this method is not easily controllable and this causes the quality exfoliated sheets to vary. Furthermore, reducing the PH of the solution and washing the sample in the final stage of process by filtration cannot separate the nanosheets. Hence, in this study, washing of the samples by distilled water in the filtration setup was replaced by centrifuge approach. The microscopic characterizations like TEM, FESEM, SAED and EDX that were carried out revealed that centrifuging the samples gave better outcomes for the Hummer's method.

  17. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    International Nuclear Information System (INIS)

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup

  18. Model of mass transfer processes in the cascade of centrifugal extractors

    Science.gov (United States)

    Zelenetskaya, E. P.; Goryunov, A. G.; Daneikina, N. V.

    2016-06-01

    The paper describes a mathematical model of mass transfer processes in a cascade of reverse-flow centrifugal extractors. Model of operation of each extractor is given as tightly coupled system of mixing and separating chambers. All model units are represented by systems of differential equations. The article presents the results of testing of the developed model, which confirmed the validity of the assumptions made in the model. The authors assessed the impact of the overflow of dense phase level on the hydrostatic position of phase interface level in the extractor. The research showed that a change in the volume of dense and light phases occurs in each apparatus of a cascade even in the steady mode. Operation of the cascade consisting of 12 series-connected centrifugal extractors was simulated in order to verify the model. Computer simulation results confirm the adequacy of the developed model.

  19. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    Energy Technology Data Exchange (ETDEWEB)

    Wardle, K.E. [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-07-01

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup.

  20. Application of two turbulence models for computation of cavitating flows in a centrifugal pump

    Science.gov (United States)

    He, M.; Guo, Q.; Zhou, L. J.; Wang, Z. W.; Wang, X.

    2013-12-01

    To seek a better numerical method to simulate the cavitating flow field in a centrifugal pump, the applications between RNG k- ε and LES turbulence model were compared by using the Zwart-Gerber-Belamri cavitation model. It was found that both the models give almost the same results with respect to pump performance and cavitation evolutions including growth, local contraction, stability and separation in the impeller passage. But the LES model can not only capture the pump suction recirculation and the low frequency fluctuation caused by it, but also combine the changes of the shaft frequency amplitude acting on the impeller with the cavitation unstable characteristics. Thus the LES model has more advantages than RNG k- ε model in calculating the unsteady cavitating flow in a centrifugal pump.

  1. Rotational spectroscopy with an optical centrifuge

    CERN Document Server

    Korobenko, Aleksey; Hepburn, John W; Milner, Valery

    2013-01-01

    We demonstrate a new spectroscopic method for studying electronic transitions in molecules with extremely broad range of angular momentum. We employ an optical centrifuge to create narrow rotational wave packets in the ground electronic state of $^{16}$O$_2$. Using the technique of resonance-enhanced multi-photon ionization, we record the spectrum of multiple ro-vibrational transitions between $X^3\\Sigma_{g}^{-}$ and $C^3\\Pi_{g}$ electronic manifolds of oxygen. Direct control of rotational excitation, extending to rotational quantum numbers as high as $N\\gtrsim 120$, enables us to interpret the complex structure of rotational spectra of $C^3\\Pi_{g}$ beyond thermally accessible levels.

  2. DESIGN PARAMETERS OF CENTRIFUGAL COMPRESSOR INDUCER

    Directory of Open Access Journals (Sweden)

    Saim KOÇAK

    1998-03-01

    Full Text Available Design characteristics of centrifugal compressor impellers working with compressible fluids are analyzed, and the design parameters of inducer are defined. The effects of incidence, deviation and deflection angles, relative eddy, rotating stall and Mach number are investigated. The relation between minimum relative Mach number of inducer and flow angle is investigated and it is observed that the minimum Mach number occurs for flow angle values between -680 and -520 . In the design, the effect of a 100 difference in flow angle is found to be less than 1 % on minimum relative Mach number.

  3. THERMODYNAMIC DESIGN OF CENTRIFUGAL COMPRESSOR FOR TURBOCHARGER

    OpenAIRE

    Sonawane Shubham*, Sondkar Pratik, Qasim Siddiqui, Phirke Indraneel, Prof. R. P. Kakde

    2016-01-01

    The purpose of a turbocharger is to increase the power output of an engine by supplying compressed air to the engine intake manifold so that fuel can be burnt efficiently. In this work, thermodynamic design of a high pressure ratio centrifugal compressor, for 75 kW class engines, was carried out. A pressure ratio of 2.8 was considered with a compressor rotational speed of 60,000 RPM. The compressor was designed for vane less diffuser. The impeller designs were obtained using ci...

  4. Design and Prototyping of Micro Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Shimpei Mizuki; Gaku Minorikawa; Toshiyuki Hirano; Yuichiro Asaga; Naoki Yamaguchi; Yutaka Ohta; Eisuke Outa

    2003-01-01

    In order to establish the design methodology of ultra micro centrifugal compressor, which is the most important component of ultra micro gas turbine unit, a 10 times of the final target size model was designed, prototyped and tested. The problems to be solved for downsizing were examined and 2-dimensional impeller was chosen as the first model due to its productivity. The conventional 1D prediction method, CFD and the inverse design were attempted. The prototyped compressor was driven by using a turbocharger and the performance characteristics were measured.

  5. Impeller blade design method for centrifugal compressors

    Science.gov (United States)

    Jansen, W.; Kirschner, A. M.

    1974-01-01

    The design of a centrifugal impeller with blades that are aerodynamically efficient, easy to manufacture, and mechanically sound is discussed. The blade design method described here satisfies the first two criteria and with a judicious choice of certain variables will also satisfy stress considerations. The blade shape is generated by specifying surface velocity distributions and consists of straight-line elements that connect points at hub and shroud. The method may be used to design radially elemented and backward-swept blades. The background, a brief account of the theory, and a sample design are described.

  6. Ultracapacitor separator

    Science.gov (United States)

    Wei, Chang; Jerabek, Elihu Calvin; LeBlanc, Jr., Oliver Harris

    2001-03-06

    An ultracapacitor includes two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. The electrolyte is a polar aprotic organic solvent and a salt. The porous separator comprises a wet laid cellulosic material.

  7. Centrifugally Stimulated Exospheric Ion Escape at Mercury

    Science.gov (United States)

    Delcourt, Dominique; Seki, K.; Terada, N.; Moore, Thomas E.

    2012-01-01

    We investigate the transport of ions in the low-altitude magnetosphere magnetosphere of Mercury. We show that, because of small spatial scales, the centrifugal effect due to curvature of the E B drift paths can lead to significant particle energization in the parallel direction. We demonstrate that because of this effect, ions with initial speed smaller than the escape speed such as those produced via thermal desorption can overcome gravity and escape into the magnetosphere. The escape route of this low-energy exosphere originating material is largely controlled by the magnetospheric convection rate. This escape route spreads over a narrower range of altitudes when the convection rate increases. Bulk transport of low-energy planetary material thus occurs within a limited region of space once moderate magnetospheric convection is established. These results suggest that, via release of material otherwise gravitationally trapped, the E B related centrifugal acceleration is an important mechanism for the net supply of plasma to the magnetosphere of Mercury.

  8. Postcardiotomy centrifugal assist: a single surgeon's experience.

    Science.gov (United States)

    Curtis, Jack J; McKenney-Knox, Charlotte A; Wagner-Mann, Colette C

    2002-11-01

    Because of the infrequent application of cardiac assist devices for postcardiotomy heart failure, most published reports include the results of learning curves from multiple surgeons. Between October 1986 and June 2001, a single surgeon used 35 Sarns Centrifugal Pumps as ventricular assist devices in 21 patients with severe hemodynamic compromise after open heart surgery (0.88% incidence). Patients' ages ranged from 39 to 77 (mean, 59.6 years). Three patients required right ventricular assist devices, 4 left ventricular assist devices, and 14 had biventricular assist devices. For all, the indication for application was inability to wean from cardiopulmonary bypass despite multiple inotropes and intraaortic balloon pumping. All were expected to be intraoperative deaths without further mechanical assistance. Patients were assisted from 2 to 434 h (median, 48 h). Fifteen patients (71.4%) were weaned from device(s), and 11 patients (52.4%) were hospital survivors. Actuarial survival in those dismissed from the hospital was 78% at 5 years and 39% at 10 years. Patients facing certain demise after cardiac surgery can be salvaged with temporary centrifugal mechanical assist. Results are competitive with that achieved with more sophisticated devices. Hospital survivors enjoy reasonable longevity.

  9. PARTICLE DISTRIBUTION IN CENTRIFUGAL ACCELERATING FIELDS

    Institute of Scientific and Technical Information of China (English)

    Yu Sirong; Zhang Xinping; He Zhenming; Liu Yaohui

    2003-01-01

    Based on continuum theory and moving law of particles, a model is presented to obtain gradient distribution of particles in centrifugal accelerating field, by which the particle distribution in gradient composite material can be predicted. The simulation shows with increases in rotating time, four regions gradually appear from the internal periphery to the external one, they are free region, transition region, steady region and surface reinforced region,and the latest three regions are defined as a rich region. Finally, the steady region disappears, and the rich region only includes transition region and surface reinforced region. The influences of centrifugal acceleration coefficient G,primary volume fraction (0,pouring temperature (p and density difference between the particle and the metal matrix on particles gradient distribution are studied in detail. The results of the theoretical analysis agree with experiment ones. Both of analysis and experiment results indicate that with the increase in G and (p, the particle distribution becomes more centralized and the consistence of particle in the surface periphery becomes larger.

  10. Some aversive characteristics of centrifugally generated gravity.

    Science.gov (United States)

    Altman, F.

    1973-01-01

    The effective weight of rats was manipulated by centrifugation. Two effective weight levels were obtained. In three escape avoidance conditions a lever press produced a change from a base level of 2.1 g to a response level of 1.1 g. In a punishment condition a response produced a change from a 1.1 g level to a 2.1 g level and in an extinction condition responses had no effect on the 2.1 g effective weight level present. All changes took 30 sec and were maintained for an additional 10 sec before a return to base level was initiated. When responses occurred closer together than the 40 sec, they delayed the return to base level by 40 sec. This 40 sec interval is referred to as response-contingent-time. The response rate and amount of response-contingent-time served as the data. The results confirmed previous data that centrifugation is aversive. The results are interpreted as indicating that the aversiveness is attributable to the increase in effective weight, and that rats can discriminate the different angular velocity-radius of rotation combinations used.

  11. Novel design for centrifugal counter-current chromatography: VI. Ellipsoid column.

    Science.gov (United States)

    Gu, Dongyu; Yang, Yi; Xin, Xuelei; Aisa, Haji Akber; Ito, Yoichiro

    2015-01-01

    A novel ellipsoid column was designed for centrifugal counter-current chromatography. Performance of the ellipsoid column with a capacity of 3.4 mL was examined with three different solvent systems composed of 1-butanol-acetic acid-water (4:1:5, v/v) (BAW), hexane-ethyl acetate-methanol-0.1 M HCl (1:1:1:1, v/v) (HEMH), and 12.5% (w/w) PEG1000 and 12.5% (w/w) dibasic potassium phosphate in water (PEG-DPP) each with suitable test samples. In dipeptide separation with BAW system, both stationary phase retention (Sf) and peak resolution (Rs) of the ellipsoid column were much higher at 0° column angle (column axis parallel to the centrifugal force) than at 90° column angle (column axis perpendicular to the centrifugal force), where elution with the lower phase at a low flow rate produced the best separation yielding Rs at 2.02 with 27.8% Sf at a flow rate of 0.07 ml/min. In the DNP-amino acid separation with HEMW system, the best results were obtained at a flow rate of 0.05 ml/min with 31.6% Sf yielding high Rs values at 2.16 between DNP-DL-glu and DNP-β-ala peaks and 1.81 between DNP-β-ala and DNP-L-ala peaks. In protein separation with PEG-DPP system, lysozyme and myolobin were resolved at Rs of 1.08 at a flow rate of 0.03 ml/min with 38.9% Sf. Most of those Rs values exceed those obtained from the figure-8 column under similar experimental conditions previously reported.

  12. Potential of a Dry Rotating-Disk Magnetic Separator

    OpenAIRE

    Gerhold, J.

    1992-01-01

    Selectivity is a severe problem in dry magnetic separation. Dry rotating-disk magnetic separator utilizes radial magnetic forces that compete against centrifugal mass forces. Genuine equilibrium of forces, which is compulsory for high selectivity can thus be achieved at a high level of magnetic force. The potential of an iron-pole separator for intergrown ferromagnetics, as well as of a superconducting system for paramagnetic materials is discussed.

  13. Process intensification technologies for biodiesel production reactive separation processes

    CERN Document Server

    Kiss, A A

    2014-01-01

    This book is among the first to address the novel process intensification technologies for biodiesel production, in particular the integrated reactive separations. It provides a comprehensive overview illustrated with many industrially relevant examples of novel reactive separation processes used in the production of biodiesel (e.g. fatty acid alkyl esters): reactive distillation, reactive absorption, reactive extraction, membrane reactors, and centrifugal contact separators. Readers will also learn about the working principles, design and control of integrated processes, while also getting a

  14. Isotope separation by laser technology

    Science.gov (United States)

    Stoll, Wolfgang

    2002-03-01

    Isotope separation processes operate on very small differences, given either by the Quotient of masses with the same number of electrons or by their mass difference. When separating isotopes of light elements in mass quantities, thermodynamic processes accounting for the quotient, either in diffusion, chemical reactivity or distillation are used. For heavy elements those quotients are very small. Therefore they need a large number of separation steps. Large plants with high energy consumption result from that. As uranium isotope separation is the most important industrial field, alternatives, taking account for the mass difference, as e.g. gas centrifuges, have been developed. They use only a fraction of the energy input, but need a very large number of machines, as the individual throughput is small. Since it was discovered, that molecules of high symmetry like Uranium-Hexafluoride as a deep-cooled gas stream can be ionized by multiple photon excitation, this process was studied in detail and in competition to the selective ionization of metal vapors, as already demonstrated with uranium. The paper reports about the principles of the laser excitation for both processes, the different laboratory scale and prototypical plants built, the difficulties with materials, as far as the metal vapor laser separation is concerned, and the difficulties experienced in the similarity in molecular spectra. An overview of the relative economic merits of the different processes and the auspices in a saturated market for uranium isotope separation, together with other potential markets for molecular laser separation, is contained in the conclusions.

  15. Evaluation of floating impeller phenomena in a Gyro centrifugal pump.

    Science.gov (United States)

    Nishimura, Ikuya; Ichikawa, S; Mikami, M; Ishitoya, H; Motomura, T; Kawamura, M; Linneweber, J; Glueck, J; Shinohara, T; Nosé, Y

    2013-01-01

    The Gyro centrifugal pump developed as a totally implantable artificial heart was designed with a free impeller, in which the rotational shaft (male bearing) of the impeller was completely separated from the female bearing. For this type of pump, it is very important to keep the proper magnet balance (impeller-magnet and actuator-magnet) in order to prevent thrombus formation and/or bearing wear. When the magnet balance is not proper, the impeller is jerked down into the bottom bearing. On the other hand, if magnet balance is proper, the impeller lifted off the bottom of the pump housing within a certain range of pumping conditions. In this study, this floating phenomenon was investigated in detail. The floating phenomenon was proved by observation of the impeller behavior using a transparent acrylic pump. The impeller floating phenomenon was mapped on a pump performance curve. The impeller floating phenomenon is affected by the magnet-magnet coupling distance and rotational speed of the impeller. In order to keep the proper magnet balance and to maintain the impeller floating phenomenon at the driving condition of right and left pump, the magnet-magnet coupling distance was altered by a spacer which was installed between the pump and actuator. It became clear that the same pump could handle different conditions (right and left ventricular assist), by just changing the thickness of the spacer. When magnet balance is proper, the floating impeller phenomenon occurs automatically in response to the impeller rev. It is called "the dynamic RPM suspension".

  16. New Measures to Safeguard Gas Centrifuge Enrichment Plants

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, Jr., James [ORNL; Garner, James R [ORNL; Whitaker, Michael [ORNL; Lockwood, Dunbar [U.S. Department of Energy, NNSA; Gilligan, Kimberly V [ORNL; Younkin, James R [ORNL; Hooper, David A [ORNL; Henkel, James J [ORNL; Krichinsky, Alan M [ORNL

    2011-01-01

    As Gas Centrifuge Enrichment Plants (GCEPs) increase in separative work unit (SWU) capacity, the current International Atomic Energy Agency (IAEA) model safeguards approach needs to be strengthened. New measures to increase the effectiveness of the safeguards approach are being investigated that will be mutually beneficial to the facility operators and the IAEA. One of the key concepts being studied for application at future GCEPs is embracing joint use equipment for process monitoring of load cells at feed and withdrawal (F/W) stations. A mock F/W system was built at Oak Ridge National Laboratory (ORNL) to generate and collect F/W data from an analogous system. The ORNL system has been used to collect data representing several realistic normal process and off-normal (including diversion) scenarios. Emphasis is placed on the novelty of the analysis of data from the sensors as well as the ability to build information out of raw data, which facilitates a more effective and efficient verification process. This paper will provide a progress report on recent accomplishments and next steps.

  17. Isolation of Methoxyfuranocoumarins From Ammi majus by Centrifugal Partition Chromatography.

    Science.gov (United States)

    Bartnik, Magdalena; Mazurek, Anna Katarzyna

    2016-01-01

    Pure methoxyfuranocoumarins were isolated from Ammi majus L. by use of low-pressure column chromatography (LPCC) followed by centrifugal partition chromatography (CPC). The concentrated petroleum ether extract from fruits of A. majus was fractionated on a silica gel column using a gradient of ethyl acetate in dichloromethane (0-80%, v/v). Coumarin-rich fractions were analyzed by thin-layer chromatography (TLC) and high-performance liquid chromatography with diode array detection (HPLC/DAD). Xanthotoxin (8-MOP) and isopimpinellin (isoP), structurally similar compounds, were isolated in one fraction (FR6). To avoid multistep and long-lasting TLC preparation, optimization of CPC conditions has been performed. In one run, an effective separation of 8-MOP and isoP was achieved. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (10 : 8 : 10 : 9; v/v) in an ascending mode (the aqueous phase was a stationary phase, and the organic phase was a mobile phase), with flow rate 3 mL/min and rotation speed 1,600 r.p.m., was used. The identification and high purities of isolated 8-MOP (98.7%) and isoP (100%) were confirmed by HPLC/DAD assay, when compared with standards. The developed CPC method could be applied to the effective isolation of 8-MOP and isoP from plant extracts. The high purity of obtained compounds makes possible further exploitation of these components in biological studies.

  18. Recent advances in centrifugal contactors design

    International Nuclear Information System (INIS)

    Advances in thedesign of the Argonne centrifugal contactor for solvent extaction are being realized as these contactors are built, tested, and used to implement the TRUEX process for the cleanup of nuclear waste liquids. These advances include (1) using off-the-shelf, face-mounted motors, (2) modifying the contractor so that relatively volatile solvents can be used, (3) adding a high-level liquid detector that can be used to alert the plant operator of process upsets, (4) providing secondary feed ports, (5) optimizing support frame design, (6) maintaining a linear design with external interstage lines so the stages can be allocated as needed for extraction, scrub, strip, and solvent cleanup operations, and (7) developing features that facilitate contractor operation in remote facilities. 11 refs., 8 figs

  19. Centrifugal acceleration of plasma in pulsar magnetosphere

    Indian Academy of Sciences (India)

    R T Gangadhara; V Krishna

    2003-12-01

    We present a relativistic model for the centrifugal acceleration of plasma bunches and the coherent radio emission in pulsar magnetosphere. We find that rotation broadens the width of leading component compared to the width of trailing component. We explain this difference in the component widths using the nested cone emission geometry. We estimate the effect of pulsar spin on the Stokes parameters, and find that the inclination between the rotation and magnetic axes can introduce an asymmetry in the circular polarization of the conal components. We analyse the single pulse polarization data of PSR B0329+54 at 606 MHz, and find that in its conal components, one sense of circular polarization dominates in the leading component while the other sense dominates in the trailing component. Our simulation shows that changing the sign of the impact parameter changes the sense of circular polarization as well as the swing of polarization angle.

  20. [Hemodynamic analysis of a centrifugal blood pump].

    Science.gov (United States)

    Wang, Yang; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Li, Qilei; Xu, Liang

    2015-01-01

    This paper built the mathematical model of a centrifugal blood pump, which was designed by ourselves, combined it with that of the human cardiovascular system and simulated the coupling system using Matlab. Then we set up the experiment platform, linked the blood pump to mock human cardiovascular system in case of three-stage heart failure, and measured aortic pressure and flow under different speed. The comparison between experiment results and simulation results not only indicates the coupling model is correct and the blood pump works well, but also shows that with the increase of blood pump speed, the pulsation of aortic pressure and flow will be reduced, this situation will affect the structure and function of blood vessels.

  1. Stability of centrifugal pump characteristic curve

    OpenAIRE

    Chmatil, Ľuboš

    2011-01-01

    Předložená diplomová práce obsahuje teoretický rozbor charakteristik odstředíveho čerpadla, podmínky stability Y(Q) charakteristiky, výpočet charakteristiky ßč(ns), úpravy vedúce k stabilizaci spirálního telesa a oběžného kola, návrh spirály, obežného kola a následný výpočet v programe Fluent. This master's thesis includes theoretical analysis of characteristics of a centrifugal pump, conditions of stability of Y(Q) characteristic, calculation of characteristics ßč(ns), modifications leadi...

  2. [Hemodynamic analysis of a centrifugal blood pump].

    Science.gov (United States)

    Wang, Yang; Yang, Ming; Xu, Zihao; Zhuang, Xiaoqi; Li, Qilei; Xu, Liang

    2015-01-01

    This paper built the mathematical model of a centrifugal blood pump, which was designed by ourselves, combined it with that of the human cardiovascular system and simulated the coupling system using Matlab. Then we set up the experiment platform, linked the blood pump to mock human cardiovascular system in case of three-stage heart failure, and measured aortic pressure and flow under different speed. The comparison between experiment results and simulation results not only indicates the coupling model is correct and the blood pump works well, but also shows that with the increase of blood pump speed, the pulsation of aortic pressure and flow will be reduced, this situation will affect the structure and function of blood vessels. PMID:26027287

  3. Numerical analysis for causes of cavitation fracture working condition on centrifugal pump

    International Nuclear Information System (INIS)

    In order to research the flow-head curve plunge caused by the cavitation of centrifugal pump, the standard k-ε turbulence model, homogeneous multiphase model and Rayleigh-Plesset equation were applied to simulate the cavitation characteristics in a centrifugal pump with specific speed of 59 under different conditions based on ANSYS CFX software. The results show that the numerical simulation result has the same trend with experiment result, and absolute error is 0.02%. The analysis of flow field shows that: the steep fall of flow-head curve is not only caused by the traditional cavitation, but also mainly caused by the Vortex loss. As the empty bubble in the passageway increases to some degree, the liquid boundary layer separation happened, then vortex appears and vortex losses. While the vortex appears originally, it has an impact on the flow-head curve. When the bubble becomes more and the whole passageway is full of vortex, cavitation fault condition happens. It reveals the vapor-liquid tow-phase flow distribution within the centrifugal pump. (authors)

  4. Task 9 - Centrifugal membrane filtration. Semi-annual report, April 1 - September 30, 1997

    International Nuclear Information System (INIS)

    This project is designed to establish the utility of a novel centrifugal membrane filtration technology for the remediation of liquid mixed waste streams at US Department of Energy (DOE) facilities in support of the DOE Environmental Management (EM) program. The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., a small business and owner of the novel centrifugal membrane filtration technology, to establish the applicability of the technology to DOE site remediation and the commercial viability of the technology for liquid mixed waste stream remediation. The technology is a uniquely configured process that makes use of ultrafiltration and centrifugal force to separate suspended and dissolved solids from liquid waste streams, producing a filtered water stream and a low-volume contaminated concentrate stream. This technology has the potential for effective and efficient waste volume minimization, the treatment of liquid tank wastes, the remediation of contaminated groundwater plumes, and the treatment of secondary liquid waste streams from other remediation processes, as well as the liquid waste stream generated during decontamination and decommissioning activities

  5. Sludge Water Characteristics Under Different Separation Methods from a Membrane Bioreactor

    KAUST Repository

    Wei, Chunhai

    2013-11-22

    The concept of sludge water was proposed to integrate the relative terminologies and its characteristics under different separation methods from a membrane bioreactor (MBR) were investigated in this study. Based on chemical oxygen demand (COD) and three-dimensional fluorescence excitation-emission matrix (F-EEM), and compared with the control (gravitational sedimentation), some suspended particulate organics or biopolymer clusters (mainly proteins) were released from sludge flocs into the supernatant after centrifugation under low to middle centrifugal forces (10-4000 g) and then aggregated into a pellet under high centrifugal forces (10000-20000 g). Filtration (1.2 μm glass fiber filter) produced sludge water with a lower biopolymers concentration than the control (gravitational sedimentation followed by filtration) due to cake layer formation during filtration. As for centrifugation followed by filtration, low to middle centrifugal forces did not significantly affect sludge water characteristics but high centrifugal forces reduced the concentrations of some proteins in sludge water from advanced analytical protocols including F-EEM and liquid chromatography with on-line organic carbon detection (LC-OCD), demonstrating a low to middle centrifugal force suitable for MBR sludge water separation. From LC-OCD, the main fractions of sludge water were humic substances and building blocks, low molecular weight neutrals and biopolymers (mainly proteins rather than polysaccharides). Supplemental materials are available for this article. Go to the publisher\\'s online edition of Separation Science and Technology to view the supplemental file. © 2013 Copyright Taylor and Francis Group, LLC.

  6. A Novel Fabrication Method for Functionally Graded Materials under Centrifugal Force: The Centrifugal Mixed-Powder Method

    Directory of Open Access Journals (Sweden)

    Eri Miura-Fujiwara

    2009-12-01

    Full Text Available One of the fabrication methods for functionally graded materials (FGMs is a centrifugal solid-particle method, which is an application of the centrifugal casting technique. However, it is the difficult to fabricate FGMs containing nano-particles by the centrifugal solid-particle method. Recently, we proposed a novel fabrication method, which we have named the centrifugal mixed-powder method, by which we can obtain FGMs containing nano-particles. Using this processing method, Cu-based FGMs containing SiC particles and Al-based FGMs containing TiO2 nano-particles on their surfaces have been fabricated. In this article, the microstructure and mechanical property of Cu/SiC and Al/TiO2 FGMs, fabricated by the centrifugal mixed-powder method are reviewed.

  7. Analysis of centrifugal convection in rotating pipes

    Science.gov (United States)

    Shtern, Vladimir; Zimin, Valery; Hussain, Fazle

    2001-08-01

    New exact solutions, obtained for centrifugal convection of a compressible fluid in pipes and annular pipes, explain axially elongated counterflow and energy separation—poorly understood phenomena occurring in vortex devices, e.g., hydrocyclones and Ranque tubes. Centrifugal acceleration (which can be up to 106 times gravity in practical vortex tubes), combined with an axial gradient of temperature (even small), induces an intense flow from the cold end to the hot end along the pipe wall and a backflow near the axis. To account for large density variations in vortex devices, we use the axial temperature gradient as a small parameter instead of the Boussinesq approximation. For weak pipe rotation, the swirl is of solid-body type and solutions are compact: vz/vza=1-4y2+3y4 and (T-Tw)/(Ta-Tw)=(1-y2)3; where y=r/rw, the subscripts w and a denote values of axial velocity vz, temperature T, and radial distance r, at the wall and on the axis. The axial gradient of pressure, being proportional to 3y2-1, has opposite directions near the wall, y=1, and near the axis, y=0; this explains the counterflow. With increasing pipe rotation, the flow starts to converge to the axis. This causes important new effects: (i) the density and swirl velocity maxima occur away from the wall (vortex core formation), (ii) the temperature near the axis becomes lower than near the wall (the Ranque effect), (iii) the axial gradient of temperature drops from the wall to the axis, and (iv) the total axial heat flux (Nu) reaches its maximum Numax≈4000 and then decreases as swirl increases. These features can be exploited for the development of a micro-heat-exchanger, e.g., for cooling computer chips.

  8. Countercurrent Separation of Natural Products: An Update

    OpenAIRE

    Friesen, J. Brent; McAlpine, James B.; Chen, Shao-Nong; Pauli, Guido F.

    2015-01-01

    This work assesses the current instrumentation, method development, and applications in countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC), collectively referred to as countercurrent separation (CCS). The article provides a critical review of the CCS literature from 2007 since our last review (J. Nat. Prod. 2008, 71, 1489–1508), with a special emphasis on the applications of CCS in natural products research. The current state of CCS is reviewed in regard to thr...

  9. A straight path centrifugal blood pump concept in the Capiox centrifugal pump.

    Science.gov (United States)

    Kijima, T; Oshiyama, H; Horiuchi, K; Nogawa, A; Hamasaki, H; Amano, N; Nojiri, C; Fukasawa, H; Akutsu, T

    1993-07-01

    This article describes comparative studies of a newly developed "straight path" centrifugal pump (Capiox centrifugal pump) targeted for open-heart surgery and circulatory support. A unique straight path design of the rotor was very effective in reducing the pump's rotational speed and prime volume. This pump was evaluated for hydraulics, hemolysis, depriming characteristics, cavitation, and heat generation. Two commercially available centrifugal pumps, the Biomedicus cone-type pump and the Sarns 3M impeller-type pump, were used as controls. The new pump required the lowest pump speed to produce the same flow rates under the same pressure loads and demonstrated the lowest hemolysis and the lowest temperature rise with the outlet clamped. The air volume required to deprime the new pump was one-third to one-half that for the other pumps, and no sign of cavitation was observed even if a small amount of air was introduced to the pump inlet under a negative pressure of 200 mm Hg.

  10. Sample of CFD optimization of a centrifugal compressor stage

    Science.gov (United States)

    Galerkin, Y.; Drozdov, A.

    2015-08-01

    Industrial centrifugal compressor stage is a complicated object for gas dynamic design when the goal is to achieve maximum efficiency. The Authors analyzed results of CFD performance modeling (NUMECA Fine Turbo calculations). Performance prediction in a whole was modest or poor in all known cases. Maximum efficiency prediction was quite satisfactory to the contrary. Flow structure in stator elements was in a good agreement with known data. The intermediate type stage “3D impeller + vaneless diffuser+ return channel” was designed with principles well proven for stages with 2D impellers. CFD calculations of vaneless diffuser candidates demonstrated flow separation in VLD with constant width. The candidate with symmetrically tampered inlet part b3 / b2 = 0,73 appeared to be the best. Flow separation takes place in the crossover with standard configuration. The alternative variant was developed and numerically tested. The obtained experience was formulated as corrected design recommendations. Several candidates of the impeller were compared by maximum efficiency of the stage. The variant with gas dynamic standard principles of blade cascade design appeared to be the best. Quasi - 3D non-viscid calculations were applied to optimize blade velocity diagrams - non-incidence inlet, control of the diffusion factor and of average blade load. “Geometric” principle of blade formation with linear change of blade angles along its length appeared to be less effective. Candidates’ with different geometry parameters were designed by 6th math model version and compared. The candidate with optimal parameters - number of blades, inlet diameter and leading edge meridian position - is 1% more effective than the stage of the initial design.

  11. Tropic responses of Phycomyces sporangiophores to gravitational and centrifugal stimuli.

    Science.gov (United States)

    DENNISON, D S

    1961-09-01

    A low-speed centrifuge was used to study the tropic responses of Phycomyces sporangiophores in darkness to the stimulus of combined gravitational and centrifugal forces. If this stimulus is constant the response is a relatively slow tropic reaction, which persists for up to 12 hours. The response is accelerated by increasing the magnitude of the gravitational-centrifugal force. A wholly different tropic response, the transient response, is elicited by an abrupt change in the gravitational-centrifugal stimulus. The transient response has a duration of only about 6 min. but is characterized by a high bending speed (about 5 degrees /min.). An analysis of the distribution of the transient response along the growing zone shows that the active phase of the response has a distribution similar to that of the light sensitivity for the light-growth and phototropic responses. Experiments in which sporangiophores are centrifuged in an inert dense fluid indicate that the sensory mechanism of the transient response is closely related to the physical deformation of the growing zone caused by the action of the gravitational-centrifugal force on the sporangiophore as a whole. However, the response to a steady gravitational-centrifugal force is most likely not connected with this deformation, but is probably triggered by the shifting of regions or particles of differing density relative to one another inside the cell. PMID:13721903

  12. Purification of Sardinella sp., Oil: Centrifugation and Bentonite Adsorbent

    Directory of Open Access Journals (Sweden)

    S.H. Suseno

    2014-01-01

    Full Text Available Centrifugation and purification using adsorbents is one example of a fish oil refining techniques applied to reduce impurities of fish oil. The study aimed to determine the sardine oil quality before treatment, to determine yield of fish oil after centrifugation treatment and to determine the influence of centrifugation speed and bentonite concentration on sardine oil quality. Factorial design with two factors was used in this study. Level of free fatty acid and peroxide value before purification was 35.53% and 170 mEq/kg. Yield of fish oil after centrifugation treatment has been ranged from 17.42±3.56 to 76.33±0.21%. The best treatment which could reduce the peroxide value and total oxidation was a treatment with centrifugation speed at 6500 rpm and bentonite concentration at 3%. Peroxide value and total oxidation of its treatment was 25.00±0.00 and 51.43±0.01 mEq/kg. The lowest value of p-anisidine was 1.29±0.05 mEq/kg and its value could be found in a treatment with centrifugation speed at 4500 rpm and bentonite concentration at 5%. The level of free fatty acid after purification process was ranged from 27.35 to 34.69%. Oil clarity tended to increase with the increase of centrifugation speed and adsorbent concentration.

  13. Performance analysis of mini centrifugal pump with splitter blades

    Science.gov (United States)

    Shigemitsu, T.; Fukutomi, J.; Wada, T.; Shinohara, H.

    2013-12-01

    Design method for a mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Then, a semi-open impeller for the mini centrifugal pump with 55mm impeller diameter is adopted in this research to take simplicity and maintenance into consideration. Splitter blades are adopted in this research to improve the performance and internal flow condition of mini centrifugal pump having large blade outlet angle. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on the performance and internal flow condition of the mini centrifugal pump. A three dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Flow condition at outlet of the rotor becomes uniform and back flow regions are suppressed in the case with the splitter blades. Further, the volute efficiency increases and the vortex loss decreases. In the present paper, the performance of the mini centrifugal pump is shown and the flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the performance analyses of the mini centrifugal pumps with and without the splitter blades are conducted.

  14. Experimental Investigation on Characteristics of Flow Instabilities in Centrifugal Pump Impeller under Part-Load Conditions

    OpenAIRE

    Denghao Wu; Yun Ren; Houlin Liu; Jiegang Mu; Lanfang Jiang

    2014-01-01

    This paper presents an experimental investigation of large-scale flow-field instabilities in a centrifugal pump impeller of low specific speed. Measurements of pump hydraulic performance and flow-field in the impeller passages were made with a hydraulic test rig and a Particle Image Velocimetry (PIV) system separately. Analyses of Q-H data and flow structures in the impeller passages were performed. Results showed that an unstable area existed in the range from 0.1QBEP to 0.6QBEP and had a cl...

  15. Centrifugal contactor modified for end stage operation in a multistage system

    Science.gov (United States)

    Jubin, Robert T.

    1990-01-01

    A cascade formed of a plurality of centrifugal contactors useful for countercurrent solvent extraction processes such as utilizable for the reprocessing of nuclear reactor fuels is modified to permit operation in the event one or both end stages of the cascade become inoperative. Weir assemblies are connected to each of the two end stages by suitable conduits for separating liquids discharged from an inoperative end stage based upon the weight of the liquid phases uses in the solvent extraction process. The weir assembly at one end stage is constructed to separate and discharge the heaviest liquid phase while the weir assembly at the other end stage is constructed to separate and discharge the lightest liquid phase. These weir assemblies function to keep the liquid discharge from an inoperative end stages on the same weight phase a would occur from an operating end stage.

  16. Application of the sextic oscillator with centrifugal barrier and the spheroidal equation for some X(5) candidate nuclei

    OpenAIRE

    Raduta, A. A.; Buganu, P.

    2013-01-01

    The eigenvalue equation associated to the Bohr-Mottelson Hamiltonian is considered in the intrinsic reference frame and amended by replacing the harmonic oscillator potential in the $\\beta$ variable with a sextic oscillator potential with centrifugal barrier plus a periodic potential for the $\\gamma$ variable. After the separation of variables, the $\\beta$ equation is quasi-exactly solved, while the solutions for the $\\gamma$ equation are just the angular spheroidal functions. An anharmonic t...

  17. Preparative Isolation of Polar Antioxidant Constituents from Abies koreana Using Centrifugal Partition Chromatography Guided by DPPH center dot-HPLC Experiment

    NARCIS (Netherlands)

    Jeon, Je-Seung; Kim, Ji Hoon; Park, Chae Lee; Kim, Chul Young

    2015-01-01

    Preparative separation of antioxidant constituents from the leaves of Abies koreana Wilson (Pinaceae) was performed by centrifugal partition chromatography (CPC) with a two-phase solvent system of ethyl acetate-isopropanol-water (9:1:10, v/v) target-guided by DPPH•-HPLC experiment. In DPPH•-HPLC exp

  18. Confusion around the tidal force and the centrifugal force

    CERN Document Server

    Matsuda, Takuya; Boffin, Henri M J

    2015-01-01

    We discuss the tidal force, whose notion is sometimes misunderstood in the public domain literature. We discuss the tidal force exerted by a secondary point mass on an extended primary body such as the Earth. The tidal force arises because the gravitational force exerted on the extended body by the secondary mass is not uniform across the primary. In the derivation of the tidal force, the non-uniformity of the gravity is essential, and inertial forces such as the centrifugal force are not needed. Nevertheless, it is often asserted that the tidal force can be explained by the centrifugal force. If we literally take into account the centrifugal force, it would mislead us. We therefore also discuss the proper treatment of the centrifugal force.

  19. Experimental study on cavitation in centrifugal pump impellers

    International Nuclear Information System (INIS)

    Investigations concerning cavitation in centrifugal impellers were carried out in a closed circuit. The value of net positive suction head (NPSH) at different head drops and at breakdown were used to verify the affinity laws

  20. MULTIOBJECT OPTIMIZATION OF A CENTRIFUGAL IMPELLER USING EVOLUTIONARY ALGORITHMS

    Institute of Scientific and Technical Information of China (English)

    Li Jun; Liu Lijun; Feng Zhenping

    2004-01-01

    Application of the multiobjective evolutionary algorithms to the aerodynamic optimization design of a centrifugal impeller is presented. The aerodynamic performance of a centrifugal impeller is evaluated by using the three-dimensional Navier-Stokes solutions. The typical centrifugal impeller is redesigned for maximization of the pressure rise and blade load and minimization of the rotational total pressure loss at the given flow conditions. The B閦ier curves are used to parameterize the three-dimensional impeller blade shape. The present method obtains many reasonable Pareto optimal designs that outperform the original centrifugal impeller. Detailed observation of the certain Pareto optimal design demonstrates the feasibility of the present multiobjective optimization method tool for turbomachinery design.

  1. TECHNOLOGY EVALUATION REPORT: RETECH'S PLASMA CENTRIFUGAL FURNACE - VOLUME I

    Science.gov (United States)

    A demonstration of the Retech, Inc. Plasma Centrifugal Furnace (PCF) was conducted under the Superfund Innovative Technology Evaluation (SITE) Program at the Department of Energy's (DOE's) Component Development and Integration Facility in Butte, Montana. The furnace uses heat gen...

  2. Centrifuging Step-Screw Conveyor for Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A variety of ISRU operations will utilize lunar regolith as feedstock. The proposed centrifuging step-screw conveyor concept will provide a well controlled robust,...

  3. Fluent-based numerical simulation of flow centrifugal fan

    Institute of Scientific and Technical Information of China (English)

    LI Xian-zhang

    2011-01-01

    Testing centrifugal fan flow field by physical laboratory is difficult because the testing system is complex and the workload is heavy, and the results observed by naked-eye deviates far from the actual value. To address this problem, the computational fluid dynamics software FLUENT was applied to establish three-dimensional model of the centrifugal fan. The numeral model was verified by comparing simulation data to experimental data. The pressure centrifugal fan and the speed changes in distribution in centrifugal fan was simulated by computational fluid dynamics software FLUENT. The simulation results show that the gas flow velocity in the impeller increases with impeller radius increase. Static pressure gradually increases when gas from the fan access is imported through fan impeller leaving fans.

  4. Investigation on complete characteristics and hydraulic transient of centrifugal pump

    International Nuclear Information System (INIS)

    An improved method was developed to obtain the complete characteristic of centrifugal pump. The conversion formula of complete characteristics is established based on the normal performance curve. An example was presented to illuminate the new method, and the complete characteristic curves of 14SA-10 centrifugal pump were obtained by the new method. The hydraulic transient of the centrifugal pump failure and start-up was simulated by method of characteristics (MOC), which quote the complete characteristics data. The results show that the inversion method is available to obtain the complete pump characteristic curves provided the normal performance curve. For hydraulic transient simulation, more accurate numerical result can be obtained, if the new model is adopted to convert the experimental normal performance curve to complete characteristics curve of centrifugal pump

  5. Measurement of ground shock in explosive centrifuge model tests

    International Nuclear Information System (INIS)

    Los Alamos National Laboratory has begun a project to simulate the formation and collapse of underground cavities produced by nuclear explosions using chemical explosions at much smaller scale on a large geotechnical centrifuge. Use of a centrifuge for this project presents instrumentation challenges which are not encountered in tests at similar scale off of the centrifuge. Electromagnetic velocity measuring methods which have been very successfully applied to such models at 1 g would be very difficult, if not impossible, to implement at 100 g. We are investigating the feasibility of other techniques for monitoring the ground shock in small-scale tests including accelerometers, stress gauges, dynamic strain meters and small, mutual-inductance particle velocity gauges. Initial results indicate that some of these techniques can be adapted for centrifuge applications. 17 references, 4 figures

  6. Steam separator modeling for various nuclear reactor transients

    International Nuclear Information System (INIS)

    In a pressurized water reactor steam generator, a moisture separator is used to separate steam and liquid and to insure that essentially dry steam is supplied to the turbine. During a steam line break or combined steam line break plus tube rupture, a number of phenomena can occur in the separator which have no counterparts during steady-state operation. How the separator will perform under these circumstances is important for two reasons, it affects the carry-over of radioactive iodine and the water inventory in the secondary side. This study has as its goal the development of a simple separator model which can be applied to a variety of steam generator for off-design conditions. Experiments were performed using air and water on three different types of centrifugal separators: a cyclone as a generic separator, a Combustion Engineering type stationary swirl vane separator, and a Westinghouse type separator. The cyclone separator system has three stages of separation: first the cyclone, then a gravity separator, and finally a chevron plate separator. The other systems have only a centrifugal separator to isolate the effect of the primary separator. Experiments were also done in MIT blowdown rig, with and without a separator, using steam and water. The separators appear to perform well at flow rates well above the design values as long as the downcomer water level is not high. High downcomer water level rather than high flow rates appear to be the primary cause of degraded performance. Appreciable carry-over from the separator section of a steam generator occurs when the drain lines from three stages of separation are unable to carry off the liquid flow. Failure scenarios of the separator for extreme range of conditions from the quasi-steady state transient to the fast transients are presented. A general model structure and simple separator models are provided

  7. Central centrifugal cicatricial alopecia: challenges and solutions.

    Science.gov (United States)

    Herskovitz, Ingrid; Miteva, Mariya

    2016-01-01

    Central centrifugal cicatricial alopecia (CCCA) is the most common scarring alopecia among African American women. Data about epidemiology, etiology, genetic inheritance, and management are scarce and come from individual reports or small series. CCCA has been associated with hot combing and traumatic hair styling for years; however, studies fail to confirm it as the sole etiologic factor. It has been shown in a small series that CCCA can be inherited in an autosomal dominant fashion, with a partial penetrance and a strong modifying effect of hairstyling and sex. CCCA presents clinically as a central area of progressive irreversible hair loss that expands to the periphery. A patchy form has also been described. Dermoscopy is helpful to identify the optimal site for the biopsy, which establishes the diagnosis. Well-designed randomized controlled trials are needed to discover the optimal management. At this point, patients are advised to avoid traction and chemical treatments; topical and intralesional steroids, calcineurin inhibitors, and minoxidil can be helpful in halting the progression. PMID:27574457

  8. Failure analysis of a polymer centrifugal impeller

    Directory of Open Access Journals (Sweden)

    Nikhil K. Kar

    2015-10-01

    Full Text Available A failure analysis investigation was performed on a fractured polymer impeller used in a respiratory blower. Light microscopy, scanning electron microscopy and finite element analysis techniques were utilized to characterize the mode(s of failure and fracture surfaces. A radial split down the impeller center was observed with symmetric fracture faces about the impeller bore. Fractographic analysis revealed brittle fracture features including Wallner lines, mirror, mist and hackle features stemming from the impeller bore, emanating radially outward. Crazed fibrils and faint fatigue striations suggest that intermittent load cycling led to initiation, and rapid propagation of multiple crack fronts originating along the impeller lip. Finite element analysis revealed a flexural condition induces localized stresses along the impeller lip. Significant wear features were also observed within the impeller bore, which may have contributed to premature failure of the impeller. The brittle fracture morphology and defects within the impeller bore suggest that premature failure occurred because of multiple interacting factors including: intermittently high centrifugal velocities, imbalance bore and shaft conditions, defects within the bore caused by machining, and stress concentrations along the circumference of the impeller lip.

  9. Investigation of Flow in a Centrifugal Pump

    Science.gov (United States)

    Fischer, Karl

    1946-01-01

    The investigation of the flow in a centrifugal pump indicated that the flow patterns in frictional fluid are fundamentally different from those in frictionless fluid. In particular, the dead air space adhering to the section side undoubtedly causes a reduction of the theoretically possible delivery head. The velocity distribution over a parallel circle is also subjected to a noticeable change as a result of the incomplete filling of the passages. The relative velocity on the pressure side of the vane, which for passages completely filled with active flow would differ little from zero even at comparatively lower than normal delivery volume, is increased, so that no rapid reverse flow occurs on the pressure side of the vane even for smaller delivery volume. It was established, further, that the flow ceases to be stationary for very small quantities of water. The inflow to the impeller can be regarded as radial for the operating range an question. The velocity triangles at the exit are subjected to a significant alteration in shape ae a result of the increased peripheral velocity, which may be of particular importance in the determination of the guide vane entrance angle.

  10. Central centrifugal cicatricial alopecia: challenges and solutions.

    Science.gov (United States)

    Herskovitz, Ingrid; Miteva, Mariya

    2016-01-01

    Central centrifugal cicatricial alopecia (CCCA) is the most common scarring alopecia among African American women. Data about epidemiology, etiology, genetic inheritance, and management are scarce and come from individual reports or small series. CCCA has been associated with hot combing and traumatic hair styling for years; however, studies fail to confirm it as the sole etiologic factor. It has been shown in a small series that CCCA can be inherited in an autosomal dominant fashion, with a partial penetrance and a strong modifying effect of hairstyling and sex. CCCA presents clinically as a central area of progressive irreversible hair loss that expands to the periphery. A patchy form has also been described. Dermoscopy is helpful to identify the optimal site for the biopsy, which establishes the diagnosis. Well-designed randomized controlled trials are needed to discover the optimal management. At this point, patients are advised to avoid traction and chemical treatments; topical and intralesional steroids, calcineurin inhibitors, and minoxidil can be helpful in halting the progression.

  11. Central centrifugal cicatricial alopecia: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Herskovitz I

    2016-08-01

    Full Text Available Ingrid Herskovitz, Mariya Miteva Department of Dermatology and Cutaneous Surgery, University of Miami L Miller School of Medicine, Miami, FL, USA Abstract: Central centrifugal cicatricial alopecia (CCCA is the most common scarring alopecia among African American women. Data about epidemiology, etiology, genetic inheritance, and management are scarce and come from individual reports or small series. CCCA has been associated with hot combing and traumatic hair styling for years; however, studies fail to confirm it as the sole etiologic factor. It has been shown in a small series that CCCA can be inherited in an autosomal dominant fashion, with a partial penetrance and a strong modifying effect of hairstyling and sex. CCCA presents clinically as a central area of progressive irreversible hair loss that expands to the periphery. A patchy form has also been described. Dermoscopy is helpful to identify the optimal site for the biopsy, which establishes the diagnosis. Well-designed randomized controlled trials are needed to discover the optimal management. At this point, patients are advised to avoid traction and chemical treatments; topical and intralesional steroids, calcineurin inhibitors, and minoxidil can be helpful in halting the progression. Keywords: hair loss, alopecia, dermatoscopy, dermoscopy, trichoscopy, black scalp, African American, scarring alopecia

  12. CALCULATION AND IMPROVEMENT OF DYNAMIC CHARACTERISTICS OF CENTRIFUGE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The modeling of the rotor-support system of a typical centrifuge is discussed. The impedance matching method, cooperating with Riccati transfer matrix method and modal analysis method are adopted to calculate its dynamic characteristics. The influences of the main parts to the critical speeds are analyzed. Based on the analysis, a critical speed in the operating speed range is tuned successfully, and thus the dynamic characteristics of the centrifuge are much improved.

  13. Design Method for Channel Diffusers of Centrifugal Compressors

    OpenAIRE

    Mykola Kalinkevych; Andriy Skoryk

    2013-01-01

    The design method for channel diffusers of centrifugal compressors, which is based on the solving of the inverse problem of gas dynamics, is presented in the paper. The concept of the design is to provide high pressure recovery of the diffuser by assuming the preseparation condition of the boundary layer along one of the channel surfaces. The channel diffuser was designed with the use of developed method to replace the vaned diffuser of the centrifugal compressor model stage. The numerical si...

  14. Design and Characterization of a Centrifugal Compressor Surge Test Rig

    OpenAIRE

    Kin Tien Lim; Se Young Yoon; Christopher P. Goyne; Zongli Lin; Allaire, Paul E.

    2011-01-01

    A detailed description of a new centrifugal compressor surge test rig is presented. The objective of the design and development of the rig is to study the surge phenomenon in centrifugal compression systems and to investigate a novel method of surge control by active magnetic bearing servo actuation of the impeller axial tip clearance. In this paper, we focus on the design, initial setup, and testing of the rig. The latter two include the commissioning of the rig and the experimental characte...

  15. Non Adiabatic Centrifugal Compressor Gas Dynamic Performance Definition

    OpenAIRE

    Soldatova, Kristina

    2014-01-01

    Most centrifugal compressors operate in conditions with negligible heat transfer (adiabatic compression). Their plant tests conditions are similar or close to adiabatic conditions. Test regulations establish measures to diminish influence of a heat transfer “compressor body – atmospheric air” to an exit temperature. Therefore a temperature rise in a compressor is used to calculate a work input coefficient and efficiency. Unlike it high pressure centrifugal compressors of gas turbines and supe...

  16. Numerical Calculation on Cavitation Pressure Pulsation in Centrifugal Pump

    OpenAIRE

    Weidong Shi; Chuan Wang; Wei Wang; Bing Pei

    2014-01-01

    In order to study the internal flow in centrifugal pump when cavitation occurs, numerical calculation of the unsteady flow field in the WP7 automobile centrifugal pump is conducted based on the Navier-Stokes equations with the RNG k-ε turbulence model and Zwart-Gerber-Belamri cavitation model. The distributions of bubble volume fraction and pressure pulsation laws in the pump are analyzed when cavitation occurs. The conclusions are as follows: the bubble volume fraction is larger on the sucti...

  17. Centrifugal potential energy : an astounding renewable energy concept

    Energy Technology Data Exchange (ETDEWEB)

    Oduniyi, I.A. [Aled Conglomerate Nigeria Ltd., Lagos (Nigeria)

    2010-07-01

    A new energy concept known as centrifugal potential energy was discussed. This new energy concept is capable of increasing the pressure, temperature and enthalpy of a fluid, without having to apply work or heat transfer to the fluid. It occurs through a change in the centrifugal potential energy of the flowing fluid in a rotating frame of reference or a centrifugal force field, where work is performed internally by the centrifugal weight of the fluid. This energy concept has resulted in new energy equations, such as the Rotational Frame Bernoulli's Equation for liquids and the Rotational Frame Steady-Flow Energy Equation for gases. Applications of these equations have been incorporated into the design of centrifugal field pumps and compressors. Rather than compressing a fluid with a physical load transfer, these devices can compress a fluid via the effect of centrifugal force applied to the object. A large amount of energy is therefore produced when this high pressure compressed working fluid expands in a turbine. When water is used as the working fluid, it could reach renewable energy densities in the range of 25-100 kJ/kg of water. When atmospheric air is used, it could reach energy densities in the range of 500-1,500 kJ/kg of air.

  18. Extraction centrifugal W-188/Re-188 generator for radiotherapeutic applications

    International Nuclear Information System (INIS)

    188 Re extraction generator for medical purposes development results are presented. The main advantage of such generator is the possibility to use as starting material the tungsten oxide of natural isotope composition irradiated in react or with mean neutron flux (1.0– 1.4·10 14 n ⋅ cm-2 ⋅ s-1). The parent (188 W) and daughter radionuclides were separated using centrifugal semicounter -current extractor developed at Physical Chemistry and Electrochemistry Institute under RAS (Russian Academy of Sciences). In the course of simulated solution experiments, optimal operating conditions were established for 188 Re production process. For this purpose, it is proposed to recover 188 Re by methylethylketone from alkaline solution (2.5 M KON + 2.5 M K2CO3) containing up to 200 g/l of W element. Methylethylketone is subsequently evaporated to dryness and residue is dissolved in isotonic solution of NaCl. An extraction generator model was built in hot cell; the process developed was then tested on radioactive solutions. The test has shown that the yield is 89% in the average and the radiochemical purity of 188 Re solution is ~ 97%. The activity of 188 W was less than 1·10-3 relative to that of 188 Re. Activity of other radioisotopes was below 1·10-4 . The content of inorganic impurities in 188 Re solution is determined only by the purity of aqueous solutions used for 188 Re dissolution. The generator model may be recommended as a basis for creation of commercial prototype of 188 Re extraction generator. Key words: extraction, generator, methylethylketone, radiopharmaceutical, metastases, preclinical research

  19. Hydrodynamic and mass transfer studies in 50 mm centrifugal extractor

    International Nuclear Information System (INIS)

    Solvent extraction is promising unit operation in reprocessing of closed nuclear fuel cycle. Unlike thermal reactor in fast reactor spent fuel reprocessing criticality and radiation damage problems are severe. This leads to the degradation of solvent and increase its inventory. To address these challenges solvent extraction equipment with small hold up and fast separation is required. Hence, centrifugal extractors are inevitable. In mass transfer studies extraction operation was carried at constant rotor speed 3000 rpm and constant flow ratio of 1 for 30%TBP and nearly 4N HNO3 system by varying total throughput from 50 ml/min to 1500 ml/min. In mass transfer studies stripping operation was carried at constant rotor speed 3000 rpm and constant flow rate of 500 ml/min for loaded TBP and slightly acidified RO water system by varying A/O flow ratio from 0.1 to 10. Mass transfer efficiency for both the cases was found to be nearly 100%. In mass transfer studies stripping operation was carried at constant total throughput of 500 ml/min and constant A/O flow ratio of 1 for rotor speeds 1500, 2000, 3000 and 4000 rpm. Mass transfer efficiency was found to slightly dependent on rotor speed. In hydrodynamics flooding limit was found under no mass transfer conditions for A/O flow ratios from 0.1 to 10 at 2500, 3000 and 3500 rpm. Maximum possible throughput was found to be ≅ 110 lph. Modeling of flooding behavior was found to be difficult

  20. Centrifugal contactor operations for UREX process flowsheet. An update

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-08-01

    The uranium extraction (UREX) process separates uranium, technetium, and a fraction of the iodine from the other components of the irradiated fuel in nitric acid solution. In May 2012, the time, material, and footprint requirements for treatment of 260 L batches of a solution containing 130 g-U/L were evaluated for two commercial annular centrifugal contactors from CINC Industries. These calculated values were based on the expected volume and concentration of fuel arising from treatment of a single target solution vessel (TSV). The general conclusions of that report were that a CINC V-2 contactor would occupy a footprint of 3.2 m 2 (0.25 m x 15 m) if each stage required twice the nominal footprint of an individual stage, and approximately 1,131 minutes or nearly 19 hours is required to process all of the feed solution. A CINC V-5 would require approximately 9.9 m 2 (0.4 m x 25 m) of floor space but would require only 182 minutes or ~ 3 hours to process the spent target solution. Subsequent comparison with the Modular Caustic Side Solvent Extraction Unit (MCU) at Savannah River Site (SRS) in October 2013 suggested that a more compact arrangement is feasible, and the linear dimension for the CINC V-5 may be reduced to about 8 m; a comparable reduction for the CINC V-2 yields a length of 5 m. That report also described an intermediate-scale (10 cm) contactor design developed by Argonne in the early 1980s that would better align with the SHINE operations as they stood in May 2012. In this report, we revisit the previous evaluation of contactor operations after discussions with CINC Industries and analysis of the SHINE process flow diagrams for the cleanup of the TSV, which were not available at the time of the first assessment.

  1. Hydraulic Performance and Mass Transfer Efficiency of Engineering Scale Centrifugal Contactors

    Energy Technology Data Exchange (ETDEWEB)

    David Meikrantz; Troy Garn; Nick Mann; Jack Law; Terry Todd

    2007-09-01

    Annular centrifugal contactors (ACCs) are being evaluated for process-scale solvent extraction operations in support of Advanced Fuel Cycle Initiative (AFCI) separations goals. Process-scale annular centrifugal contactors have the potential for high stage efficiency if properly employed and optimized for the application. Hydraulic performance issues related to flow instability and classical flooding are likely unimportant, especially for units with high throughputs. However, annular mixing increases rapidly with increasing rotor diameter while maintaining a fixed g force at the rotor wall. In addition, for engineering/process-scale contactors, elevated rotor speeds and/or throughput rates, can lead to organic phase foaming at the rotor discharge collector area. Foam buildup in the upper rotor head area can aspirate additional vapor from the contactor housing resulting in a complete loss of separation equilibrium. Variable speed drives are thus desirable to optimize and balance the operating parameters to help ensure acceptable performance. Proper venting of larger contactors is required to balance pressures across individual stages and prevent vapor lock due to foam aspiration.

  2. A wireless centrifuge force microscope (CFM) enables multiplexed single-molecule experiments in a commercial centrifuge

    Science.gov (United States)

    Hoang, Tony; Patel, Dhruv S.; Halvorsen, Ken

    2016-08-01

    The centrifuge force microscope (CFM) was recently introduced as a platform for massively parallel single-molecule manipulation and analysis. Here we developed a low-cost and self-contained CFM module that works directly within a commercial centrifuge, greatly improving accessibility and ease of use. Our instrument incorporates research grade video microscopy, a power source, a computer, and wireless transmission capability to simultaneously monitor many individually tethered microspheres. We validated the instrument by performing single-molecule force shearing of short DNA duplexes. For a 7 bp duplex, we observed over 1000 dissociation events due to force dependent shearing from 2 pN to 12 pN with dissociation times in the range of 10-100 s. We extended the measurement to a 10 bp duplex, applying a 12 pN force clamp and directly observing single-molecule dissociation over an 85 min experiment. Our new CFM module facilitates simple and inexpensive experiments that dramatically improve access to single-molecule analysis.

  3. A wireless centrifuge force microscope (CFM) enables multiplexed single-molecule experiments in a commercial centrifuge.

    Science.gov (United States)

    Hoang, Tony; Patel, Dhruv S; Halvorsen, Ken

    2016-08-01

    The centrifuge force microscope (CFM) was recently introduced as a platform for massively parallel single-molecule manipulation and analysis. Here we developed a low-cost and self-contained CFM module that works directly within a commercial centrifuge, greatly improving accessibility and ease of use. Our instrument incorporates research grade video microscopy, a power source, a computer, and wireless transmission capability to simultaneously monitor many individually tethered microspheres. We validated the instrument by performing single-molecule force shearing of short DNA duplexes. For a 7 bp duplex, we observed over 1000 dissociation events due to force dependent shearing from 2 pN to 12 pN with dissociation times in the range of 10-100 s. We extended the measurement to a 10 bp duplex, applying a 12 pN force clamp and directly observing single-molecule dissociation over an 85 min experiment. Our new CFM module facilitates simple and inexpensive experiments that dramatically improve access to single-molecule analysis. PMID:27587129

  4. Separations chemistry

    International Nuclear Information System (INIS)

    Results of studies on the photochemistry of aqueous Pu solutions and the stability of iodine in liquid and gaseous CO2 are reported. Progress is reported in studies on: the preparation of macroporous bodies filled with oxides and sulfides to be used as adsorbents; the beneficiation of photographic wastes; the anion exchange adsorption of transition elements from thiosulfate solutions; advanced filtration applications of energy significance; high-resolution separations; and, the examination of the separation agents, octylphenylphosphoric acid (OPPA) and trihexyl phosphate (THP)

  5. Product separator

    Science.gov (United States)

    Welsh, Robert A.; Deurbrouck, Albert W.

    1976-01-20

    A secondary light sensitive photoelectric product separator for use with a primary product separator that concentrates a material so that it is visually distinguishable from adjacent materials. The concentrate separation is accomplished first by feeding the material onto a vibratory inclined surface with a liquid flow, such as a wet concentrating table. Vibrations generally perpendicular to the stream direction of flow cause the concentrate to separate from its mixture according to its color. When the concentrate and its surrounding stream reach the recovery end of the table, a detecting device notes the line of color demarcation and triggers a signal if it differs from a normal condition. If no difference is noted nothing moves on the second separator. However, if a difference is detected in the constant monitoring of the color line's location, a product splitter and recovery unit normally positioned near the color line at the recovery end, moves to a new position. In this manner the selected separated concentrate is recovered at a maximum rate regardless of variations in the flow stream or other conditions present.

  6. Parametric representation of centrifugal pump homologous curves

    Energy Technology Data Exchange (ETDEWEB)

    Veloso, Marcelo A.; Mattos, Joao R.L. de, E-mail: velosom@cdtn.br, E-mail: jrmattos@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Essential for any mathematical model designed to simulate flow transient events caused by pump operations is the pump performance data. The performance of a centrifugal pump is characterized by four basic quantities: the rotational speed, the volumetric flow rate, the dynamic head, and the hydraulic torque. The curves showing the relationships between these four variables are called the pump characteristic curves. The characteristic curves are empirically developed by the pump manufacturer and uniquely describe head and torque as functions of volumetric flow rate and rotation speed. Because of comprising a large amount of points, this configuration is not suitable for computational purposes. However, it can be converted to a simpler form by the development of the homologous curves, in which dynamic head and hydraulic torque ratios are expressed as functions of volumetric flow and rotation speed ratios. The numerical use of the complete set of homologous curves requires specification of sixteen partial curves, being eight for the dynamic head and eight for the hydraulic torque. As a consequence, the handling of homologous curves is still somewhat complicated. In solving flow transient problems that require the pump characteristic data for all the operation zones, the parametric form appears as the simplest way to deal with the homologous curves. In this approach, the complete characteristics of a pump can be described by only two closed curves, one for the dynamic head and other for the hydraulic torque, both in function of a single angular coordinate defined adequately in terms of the quotient between volumetric flow ratio and rotation speed ratio. The usefulness and advantages of this alternative method are demonstrated through a practical example in which the homologous curves for a pump of the type used in the main coolant loops of a pressurized water reactor (PWR) are transformed to the parametric form. (author)

  7. Performance analysis of a centrifugal compressor with variable inlet guide vanes

    Institute of Scientific and Technical Information of China (English)

    XIAO Jun; GU Chuangang; SHU Xinwei; GAO Chuang

    2007-01-01

    The flow in a centrifugal compressor stage with variable inlet guide vanes (VIGVs) is investigated by numerical simulation in this paper.Analysis of the performance curves and relative velocity vectograms indicates that performance curves shift toward small flow domain when VIGVs turn positively,and toward large flow domain when VIGVs turn negatively.Stage efficiency drops quickly after work condition enters a small flow domain through the peak efficiency point.Under the circumstance of large setting angles of the guide vanes,there exist obvious flow separations in guide vane passages within wide flow ranges,and back flow regions can be located at the front of splitter suction surfaces under large flow conditions,while under the condition of small flow,flow separations occur on suction surfaces of long blades.

  8. Use and maintenance of centrifuging machine in labs%实验室离心机使用、保养和维修探讨

    Institute of Scientific and Technical Information of China (English)

    吕炳辉

    2012-01-01

    离心机是科学生产和医疗卫生系统中的常用设备。目前,实验室常用的电动离心机有低速、高速离心机和低速、高速冷冻离心机以及超速分析、制备两用冷冻离心机等多种型号。通过探讨实验室离心机设备使用、保养及一些维护常识,对常见故障维修案例的分析,为实验室维修人员提供一些常用的快捷维修方法,确保实验室仪器的正常运转。%Centrifuge is used to separately,enrich and purify material by the centrifugal force from rotation.Centrifuge is often applied in area of scientific production and medical equipment.Laboratory centrifuges are commonly working in electric low-speed,high-speed and refrigerated,the speed analysis and preparation of dual-use refrigerated models and so on.This paper argues information of centrifugal machine about utility and maintenance.We also provide some shortcut and convenient ways to maintenance man for laboratory instrument working order through some examples.

  9. Neutron diffraction analyses of U-(6-10 wt.%)Mo alloy powders fabricated by centrifugal atomization

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Man [Advanced Fuel Technology Development Division, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong, Daejeon 305-353 (Korea, Republic of); Ryu, Ho Jin, E-mail: hjryu@kaeri.re.k [Advanced Fuel Technology Development Division, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Ki Hwan; Lee, Don Bae; Lee, Yoon Sang [Advanced Fuel Technology Development Division, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong, Daejeon 305-353 (Korea, Republic of); Lee, Jeong Soo; Seong, Baek Seok [Neutron Science Division, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Chang Kyu [Advanced Fuel Technology Development Division, Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong, Daejeon 305-353 (Korea, Republic of); Cornen, Marilyne [INSA de Rennes, UMR CNRS 6226 Sciences Chimiques de Rennes/Chimie-Metallurgie, 20 Avenue des Buttes de Coesmes, 35043 Rennes Cedex (France)

    2010-02-15

    Lattice parameters of U-(6-10 wt.%)Mo alloy powders fabricated by a centrifugal atomization technique were measured by neutron diffraction analyses. A micro-segregation of Mo at cell boundaries was observed in the centrifugally atomized U-Mo alloy powders with varying Mo content. Lattice parameters of gamma phases decrease linearly with the increasing Mo content. By separating the overlapped diffraction peaks from cell boundaries and cell interior, lattice parameters and Mo contents of each region were calculated. The Mo content at cell boundaries is about 2-5 at.% lower than that in the cell interior and the lattice parameters for the cell boundaries are higher than those for the cell interior of the atomized U-Mo powder.

  10. Neutron diffraction analyses of U-(6-10 wt.%)Mo alloy powders fabricated by centrifugal atomization

    Science.gov (United States)

    Park, Jong Man; Ryu, Ho Jin; Kim, Ki Hwan; Lee, Don Bae; Lee, Yoon Sang; Lee, Jeong Soo; Seong, Baek Seok; Kim, Chang Kyu; Cornen, Marilyne

    2010-02-01

    Lattice parameters of U-(6-10 wt.%)Mo alloy powders fabricated by a centrifugal atomization technique were measured by neutron diffraction analyses. A micro-segregation of Mo at cell boundaries was observed in the centrifugally atomized U-Mo alloy powders with varying Mo content. Lattice parameters of gamma phases decrease linearly with the increasing Mo content. By separating the overlapped diffraction peaks from cell boundaries and cell interior, lattice parameters and Mo contents of each region were calculated. The Mo content at cell boundaries is about 2-5 at.% lower than that in the cell interior and the lattice parameters for the cell boundaries are higher than those for the cell interior of the atomized U-Mo powder.

  11. Comparative analysis of discrete exosome fractions obtained by differential centrifugation

    DEFF Research Database (Denmark)

    Jeppesen, Dennis Kjølhede; Hvam, Michael L; Primdahl-Bengtson, Bjarke;

    2014-01-01

    BACKGROUND: Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete ultracentrifugat......BACKGROUND: Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete...... ultracentrifugation speeds on the purification from different cell types, however, is limited. METHODS: We examined the effect of applying differential centrifugation g-forces ranging from 33,000×g to 200,000×g on exosome yield and purity, using 2 unrelated human cell lines, embryonic kidney HEK293 cells and bladder...... of phenol red and cleared by 200,000×g overnight centrifugation. The centrifugation tube fill level impacted the sedimentation efficacy. Comparative analysis by NTA, protein quantification, and detection of exosomal and contamination markers identified differences in vesicle size, concentration...

  12. Experience with the Sarns centrifugal pump in postcardiotomy ventricular failure.

    Science.gov (United States)

    Curtis, J J; Walls, J T; Schmaltz, R; Boley, T M; Nawarawong, W; Landreneau, R J

    1992-09-01

    The reported clinical use of the Sarns centrifugal pump (Sarns, Inc./3M, Ann Arbor, Mich.) as a cardiac assist device for postcardiotomy ventricular failure is limited. During a 25-month period ending November 1988, we used 40 Sarns centrifugal pumps as univentricular or biventricular cardiac assist devices in 27 patients who could not be weaned from cardiopulmonary bypass despite maximal pharmacologic and intraaortic balloon support. Eighteen men and nine women with a mean age of 60.4 years (28 to 83) required assistance. Left ventricular assist alone was used in 12 patients, right ventricular assist in 2, and biventricular assist in 13. The duration of assist ranged from 2 to 434 hours (median 45). Centrifugal assist was successful in weaning 100% of the patients. Ten of 27 patients (37%) improved hemodynamically, allowing removal of the device(s), and 5 of 27 (18.5%) survived hospitalization. Survival of patients requiring left ventricular assist only was 33.3% (4/12). Complications were common and included renal failure, hemorrhage, coagulopathy, ventricular arrhythmias, sepsis, cerebrovascular accident, and wound infection. During 3560 centrifugal pump hours, no pump thrombosis was observed. The Sarns centrifugal pump is an effective assist device when used to salvage patients who otherwise cannot be weaned from cardiopulmonary bypass. Statistical analysis of preoperative patient characteristics, operative risk factors, and postoperative complications failed to predict which patients would be weaned from cardiac assist or which would survive.

  13. Centrifuge modelling - migration of radionuclides from engineered trenches

    International Nuclear Information System (INIS)

    This report provides an overview of some centrifuge small-scale physical model tests and 1g experimental and theoretical work relating to the sub-surface migration of a model pollutant (sodium chloride) from a notional prototype surface landfill of width 25 metres and depth 3 metres cut into a 20 metre deep layer of nominally uniform soil overlying a more permeable base layer. An introduction is given to the application of geotechnical centrifuge modelling techniques to pollutant migration studies. Experiments performed at 1/100th scale using the Cambridge 10 metre diameter Geotechnical Beam Centrifuge simulating transport through silt over prototype time periods of around 35 years, are summarised. Comparisons of data with calculations using early versions of the POLLUTE and MIGRATE computer codes are presented. An experiment at 1/400th scale using the new Cambridge Geotechnical Drum Centrifuge, involving transport through clay over a prototype time period of around 1000 years, is described. Potential future uses of centrifuge modelling techniques to simulate long-term migration through more complex hydrological environments are also discussed. (author)

  14. PARTICLE SEPARATION METHOD

    Science.gov (United States)

    Anderson, N.G.

    1963-01-29

    An improved method of sedimentation is described. A series of spaced surfaces of powdered material positioned normal to the centrifugal field concentrates the larger, slower moving molecules of a liquid and hastens sedimentation. (AEC)

  15. Fault diagnosis of monoblock centrifugal pump using SVM

    Directory of Open Access Journals (Sweden)

    V. Muralidharan

    2014-09-01

    Full Text Available Monoblock centrifugal pumps are employed in variety of critical engineering applications. Continuous monitoring of such machine component becomes essential in order to reduce the unnecessary break downs. At the outset, vibration based approaches are widely used to carry out the condition monitoring tasks. Particularly fuzzy logic, support vector machine (SVM and artificial neural networks were employed for continuous monitoring and fault diagnosis. In the present study, the application of SVM algorithm in the field of fault diagnosis and condition monitoring is discussed. The continuous wavelet transforms were calculated for different families and at different levels. The computed transformation coefficients form the feature set for the classification of good and faulty conditions of the components of centrifugal pump. The classification accuracies of different continuous wavelet families at different levels were calculated and compared to find the best wavelet for the fault diagnosis of the monoblock centrifugal pump.

  16. Oscillatory Counter-Centrifugation: Effects of History and Lift Forces

    Science.gov (United States)

    Nadim, Ali

    2014-11-01

    This work is co-authored with my doctoral student Shujing Xu and is dedicated to the memory of my doctoral advisor Howard Brenner who enjoyed thought experiments related to rotating systems. Oscillatory Counter-Centrifugation refers to our theoretical discovery that within a liquid-filled container that rotates in an oscillatory manner about a fixed axis as a rigid body, a suspended particle can be made to migrate on average in the direction opposite to that of ordinary centrifugation. That is, a heavy (or light) particle can move toward (or away from) the rotation axis, when the frequency of oscillations is high enough. In this work we analyze the effects of the Basset history force and the Saffman lift force on particle trajectories and find that the counter-centrifugation phenomenon persists even when these forces are active.

  17. Investigation of Surge Behavior in a Micro Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    Shimpei MIZUKI; Yuichiro ASAGA; Yushi ONO; Hoshio TSUJITA

    2006-01-01

    This paper reports the experimental and theoretical study of the surge occurred in prototyping an ultra micro centrifugal compressor. As the first step, the 10 times size model of an ultra micro centrifugal compressor having the 40 mm outer diameter was designed and manufactured. The detailed experimental investigations for the transient behavior of surge with several different values of B parameter were carried out. The experimental results during the surge were compared with those obtained by the non-linear lumped parameter theory in order to validate the effectiveness of the theoretical surge model for the micro centrifugal compressor. As a result, the quite different behavior of the surge appeared for the different values of B both in the experiment and in the analysis.

  18. Space Station Centrifuge: A Requirement for Life Science Research

    Science.gov (United States)

    Smith, Arthur H.; Fuller, Charles A.; Johnson, Catherine C.; Winget, Charles M.

    1992-01-01

    A centrifuge with the largest diameter that can be accommodated on Space Station Freedom is required to conduct life science research in the microgravity environment of space. (This was one of the findings of a group of life scientists convened at the University of California, Davis, by Ames Research Center.) The centrifuge will be used as a research tool to understand how gravity affects biological processes; to provide an on-orbit one-g control; and to assess the efficacy of using artificial gravity to counteract the deleterious biological effect of space flight. The rationale for the recommendation and examples of using ground-based centrifugation for animal and plant acceleration studies are presented. Included are four appendixes and an extensive bibliography of hypergravity studies.

  19. Centrifuge Techniques and Apparatus for Transport Experiments in Porous Media

    Energy Technology Data Exchange (ETDEWEB)

    Earl D. Mattson; Carl D. Paler; Robert W. Smith; Markus Flury

    2010-06-01

    This paper describes experimental approaches and apparatus that we have developed to study solute and colloid transport in porous media using Idaho National Laboratory's 2-m radius centrifuge. The ex-perimental techniques include water flux scaling with applied acceleration at the top of the column and sub-atmospheric pressure control at the column base, automation of data collection, and remote experimental con-trol over the internet. These apparatus include a constant displacement piston pump, a custom designed liquid fraction collector based on switching valve technology, and modified moisture monitoring equipment. Suc-cessful development of these experimental techniques and equipment is illustrated through application to transport of a conservative tracer through unsaturated sand column, with centrifugal acceleration up to 40 gs. Development of such experimental equipment that can withstand high accelerations enhances the centrifuge technique to conduct highly controlled unsaturated solute/colloid transport experiments and allows in-flight liquid sample collection of the effluent.

  20. Parametric performance evaluation of a hydraulic centrifugal pump

    Science.gov (United States)

    Heo, M. W.; Y Kim, K.; Ma, S. B.; Yoo, I. S.; Choi, W. C.; Kim, J. H.; Choi, Y. S.

    2014-03-01

    Parametric study of a hydraulic centrifugal pump with backward curved blades has been performed numerically using three-dimensional Reynolds-averaged Navier-Stokes equations. The shear stress transport turbulence model was used for analysis of turbulence. The finite volume method and an unstructured grid system were used for the numerical solution. The optimal grid system in the computational domain was selected through a grid dependency test. Tested parameters were related to the geometry of the impeller and volute: seven variables defining the hub and shroud contours and the blades angle of impeller, and two variables defining the inlet width and expansion angle of volute. The effects of these parameters on the hydrodynamic performance of the centrifugal pump have been investigated. It was found that the centrifugal water pump with the twisted blades has the enhancing efficiency compared to the straight blades pump.

  1. Design Optimization of a Centrifugal Fan with Splitter Blades

    Science.gov (United States)

    Heo, Man-Woong; Kim, Jin-Hyuk; Kim, Kwang-Yong

    2015-05-01

    Multi-objective optimization of a centrifugal fan with additionally installed splitter blades was performed to simultaneously maximize the efficiency and pressure rise using three-dimensional Reynolds-averaged Navier-Stokes equations and hybrid multi-objective evolutionary algorithm. Two design variables defining the location of splitter, and the height ratio between inlet and outlet of impeller were selected for the optimization. In addition, the aerodynamic characteristics of the centrifugal fan were investigated with the variation of design variables in the design space. Latin hypercube sampling was used to select the training points, and response surface approximation models were constructed as surrogate models of the objective functions. With the optimization, both the efficiency and pressure rise of the centrifugal fan with splitter blades were improved considerably compared to the reference model.

  2. Design Method for Single-Blade Centrifugal Pump Impeller

    Science.gov (United States)

    Nishi, Yasuyuki; Fujiwara, Ryota; Fukutomi, Junichiro

    The sewage pumps are demanded a high pump efficiency and a performance in passing foreign bodies. Therefore, the impeller used by these usages requires the large passed particle size (minimum particle size in the pump). However, because conventional design method of pump impeller results in small impeller exit width, it is difficult to be applied to the design of single-blade centrifugal pump impeller which is used as a sewage pump. This paper proposes a design method for single-blade centrifugal pump impeller. As a result, the head curve of the impeller designed by the proposed design method satisfied design specifications, and pump efficiency was over 62% more than conventional single-blade centrifugal pump impeller. By comparing design values with CFD analysis values, the suction velocity ratio of the design parameter agreed well with each other, but the relative velocity ratio did not agree due to the influence of the backflow of the impeller entrance.

  3. Centrifugally activated bearing for high-speed rotating machinery

    Science.gov (United States)

    Post, Richard F.

    1994-01-01

    A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

  4. Secondary Containment Design for a High Speed Centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, K.W.

    1999-03-01

    Secondary containment for high speed rotating machinery, such as a centrifuge, is extremely important for operating personnel safety. Containment techniques can be very costly, ungainly and time consuming to construct. A novel containment concept is introduced which is fabricated out of modular sections of polycarbonate glazed into a Unistrut metal frame. A containment study for a high speed centrifuge is performed which includes the development of parameters for secondary containment design. The Unistrut/polycarbonate shield framing concept is presented including design details and proof testing procedures. The economical fabrication and modularity of the design indicates a usefulness for this shielding system in a wide variety of containment scenarios.

  5. Centrifuge modelling of a laterally cyclic loaded pile

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte; Leth, Caspar Thrane; Hededal, Ole

    2010-01-01

    A total number of 9 static and 6 cyclic centrifuge tests on laterally loaded piles in very dense, dry sand was erformed. The prototype dimensions of the piles were 1 meter in diameter and penetration depths varying from 6 to 10 meters. The static tests were used to investigate the initial subgrade...... reaction modulus and as a reference for cyclic tests. For the cyclic tests the accumulation of deflections and the change in secant stiffness of the soil from repetitive loading were investigated. From all the tests carried out accumulations of deflections were seen. rom the centrifuge tests it was seen...

  6. Aspiration spiral-flow type centrifugal flotation machine

    Institute of Scientific and Technical Information of China (English)

    陈文义

    2002-01-01

    Aspiration spiral flow type centrifugal flotation machine takes full advantage of centrifugal force field and gravitational field, and strengthens flotation of coal slurry. As a new-type flotation machine of high efficiency, its key component is bubble generator. Which completes the process of ore pulp inflation and liberalization. The design, parameters and working principle of bubble generator provide the design of the same device in similar equipment with reference. The result of industrial operation shows that this machine is of such features as small occupational area, greater concentration ratio, high processing capacity, high efficiency and lower investment etc.

  7. Design Method for Channel Diffusers of Centrifugal Compressors

    Directory of Open Access Journals (Sweden)

    Mykola Kalinkevych

    2013-01-01

    Full Text Available The design method for channel diffusers of centrifugal compressors, which is based on the solving of the inverse problem of gas dynamics, is presented in the paper. The concept of the design is to provide high pressure recovery of the diffuser by assuming the preseparation condition of the boundary layer along one of the channel surfaces. The channel diffuser was designed with the use of developed method to replace the vaned diffuser of the centrifugal compressor model stage. The numerical simulation of the diffusers was implemented by means of CFD software. Obtained gas dynamic characteristics of the designed diffuser were compared to the base vaned diffuser of the compressor stage.

  8. Open-cycle centrifugal vapor-compression heat pump

    Science.gov (United States)

    Burgmeier, L. R.; Horner, J. E.

    1987-11-01

    The objectives of the program were: (1) to develop an open cycle, high lift, centrifugal steam compressor system that can be efficiently retrofitted to existing multi-effect and high temperature differential evaporators while maintaining the cost benefits of a single stage centrifugal compressor, and (2) to demonstrate the energy saving cost benefits of driving the compressor with a natural gas fueled gas turbine engine. The turbine exhaust was to be used for final drying of the product that was evaporated. The installation of the system is described along with the test activities through May 1987.

  9. On the characteristics of centrifugal-reciprocating machines. [cryogenic coolers

    Science.gov (United States)

    Higa, W. H.

    1980-01-01

    A method of compressing helium gas for cryogenic coolers is presented which uses centrifugal force to reduce the forces on the connecting rod and crankshaft in the usual reciprocating compressor. This is achieved by rotating the piston-cylinder assembly at a speed sufficient for the centrifugal force on the piston to overcome the compressional force due to the working fluid. The rotating assembly is dynamically braked in order to recharge the working space with fluid. The intake stroke consists of decelerating the rotating piston-cylinder assembly and the exhaust stroke consists of accelerating the assembly.

  10. Blade Crack Detection of Centrifugal Fan Using Adaptive Stochastic Resonance

    OpenAIRE

    Bingbing Hu; Bing Li

    2015-01-01

    Centrifugal fans are widely used in various industries as a kind of turbo machinery. Among the components of the centrifugal fan, the impeller is a key part because it is used to transform kinetic energy into pressure energy. Crack in impeller’s blades is one of the serious hidden dangers. It is important to detect the cracks in the blades as early as possible. Based on blade vibration signals, this research applies an adaptive stochastic resonance (ASR) method to diagnose crack fault in cent...

  11. The effect of gas fraction on centrifugal pump

    Science.gov (United States)

    Zhu, Z. T.; Wang, Y.; Zhao, L. F.; Ning, C.; Xie, S. F.; Liu, Z. C.

    2015-01-01

    In order to study the multiphase flow field in M125 centrifugal pump, three-dimensional modeling was used for internal flow through three-dimensional software Pro/E. Then based on SST turbulence model combining with Rayleigh-Plesset cavitation model, and structured grid to simulate the hydraulic characteristics of volute and impeller within different gas conditions. The velocity, pressure and gas volume fraction distributions of the interior flow field of volute and impeller were obtained and analyzed, which revealed the effect of gas fractions on the flow characteristic of the centrifugal pump.

  12. Flow in a Low Specific Speed Centrifugal Pump Using PIV

    OpenAIRE

    Cui Dai; Liang Dong

    2013-01-01

    The interflow plays important roles in centrifugal pump design. In order to study the effect of rotation and z-axis on internal flow, two-dimensional particle image velocimetry (PIV) measurements have been performed to measure the steady velocity field on three planes in all impeller passages of a low specific-speed centrifugal pump. The results show that the relative velocity flows in blade passages are obviously different in terms of the positions of the blade relative to the tongue. The in...

  13. Apparatus and method for centrifugation and robotic manipulation of samples

    Science.gov (United States)

    Vellinger, John C. (Inventor); Ormsby, Rachel A. (Inventor); Kennedy, David J. (Inventor); Thomas, Nathan A. (Inventor); Shulthise, Leo A. (Inventor); Kurk, Michael A. (Inventor); Metz, George W. (Inventor)

    2007-01-01

    A device for centrifugation and robotic manipulation of specimen samples, including incubating eggs, and uses thereof are provided. The device may advantageously be used for the incubation of avian, reptilian or any type of vertebrate eggs. The apparatus comprises a mechanism for holding samples individually, rotating them individually, rotating them on a centrifuge collectively, injecting them individually with a fixative or other chemical reagent, and maintaining them at controlled temperature, relative humidity and atmospheric composition. The device is applicable to experiments involving entities other than eggs, such as invertebrate specimens, plants, microorganisms and molecular systems.

  14. GPS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  15. HRS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  16. Component Separations

    OpenAIRE

    Heller, Lior; McNichols, Colton H.; Ramirez, Oscar M.

    2012-01-01

    Component separation is a technique used to provide adequate coverage for midline abdominal wall defects such as a large ventral hernia. This surgical technique is based on subcutaneous lateral dissection, fasciotomy lateral to the rectus abdominis muscle, and dissection on the plane between external and internal oblique muscles with medial advancement of the block that includes the rectus muscle and its fascia. This release allows for medial advancement of the fascia and closure of up to 20-...

  17. Component separations.

    Science.gov (United States)

    Heller, Lior; McNichols, Colton H; Ramirez, Oscar M

    2012-02-01

    Component separation is a technique used to provide adequate coverage for midline abdominal wall defects such as a large ventral hernia. This surgical technique is based on subcutaneous lateral dissection, fasciotomy lateral to the rectus abdominis muscle, and dissection on the plane between external and internal oblique muscles with medial advancement of the block that includes the rectus muscle and its fascia. This release allows for medial advancement of the fascia and closure of up to 20-cm wide defects in the midline area. Since its original description, components separation technique underwent multiple modifications with the ultimate goal to decrease the morbidity associated with the traditional procedure. The extensive subcutaneous lateral dissection had been associated with ischemia of the midline skin edges, wound dehiscence, infection, and seroma. Although the current trend is to proceed with minimally invasive component separation and to reinforce the fascia with mesh, the basic principles of the techniques as described by Ramirez et al in 1990 have not changed over the years. Surgeons who deal with the management of abdominal wall defects are highly encouraged to include this technique in their collection of treatment options. PMID:23372455

  18. Flow control of a centrifugal fan in a commercial air conditioner

    Science.gov (United States)

    Kim, Jiyu; Bang, Kyeongtae; Choi, Haecheon; Seo, Eung Ryeol; Kang, Yonghun

    2015-11-01

    Air-conditioning fans require a low noise level to provide user comfort and quietness. The aerodynamic noise sources are generated by highly unsteady, turbulent structures near the fan blade. In this study, we investigate the flow characteristics of a centrifugal fan in an air-conditioner indoor unit and suggest control ideas to develop a low noise fan. The experiment is conducted at the operation condition where the Reynolds number is 163000 based on the blade tip velocity and chord length. Intermittent separation occurs at the blade leading edge and thus flow significantly fluctuates there, whereas vortex shedding occurs at the blade trailing edge. Furthermore, the discharge flow observed in the axial plane near the shroud shows low-frequency intermittent behaviors, resulting in high Reynolds stresses. To control these flow structures, we modify the shapes of the blade leading edge and shroud of the centrifugal fan and obtain noise reduction. The flow characteristics of the base and modified fans will be discussed. Supported by 0420-20130051.

  19. Design and optimization of a single stage centrifugal compressor for a solar dish-Brayton system

    Science.gov (United States)

    Wang, Yongsheng; Wang, Kai; Tong, Zhiting; Lin, Feng; Nie, Chaoqun; Engeda, Abraham

    2013-10-01

    According to the requirements of a solar dish-Brayton system, a centrifugal compressor stage with a minimum total pressure ratio of 5, an adiabatic efficiency above 75% and a surge margin more than 12% needs to be designed. A single stage, which consists of impeller, radial vaned diffuser, 90° crossover and two rows of axial stators, was chosen to satisfy this system. To achieve the stage performance, an impeller with a 6:1 total pressure ratio and an adiabatic efficiency of 90% was designed and its preliminary geometry came from an in-house one-dimensional program. Radial vaned diffuser was applied downstream of the impeller. Two rows of axial stators after 90° crossover were added to guide the flow into axial direction. Since jet-wake flow, shockwave and boundary layer separation coexisted in the impeller-diffuser region, optimization on the radius ratio of radial diffuser vane inlet to impeller exit, diffuser vane inlet blade angle and number of diffuser vanes was carried out at design point. Finally, an optimized centrifugal compressor stage fulfilled the high expectations and presented proper performance. Numerical simulation showed that at design point the stage adiabatic efficiency was 79.93% and the total pressure ratio was 5.6. The surge margin was 15%. The performance map including 80%, 90% and 100% design speed was also presented.

  20. Simulation and analysis of multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine enantiomers☆

    Institute of Scientific and Technical Information of China (English)

    Ping Wen; Kewen Tang; Jicheng Zhou; Panliang Zhang

    2015-01-01

    Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid–liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine (PGL) enantiomers. The influence of phase ratio, extractant concentra-tion, and PF6−concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PF6−concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeq (equal enantiomeric excess) can reach to 99%.

  1. Numerical Flow Simulation in a Centrifugal Pump at Design and Off-Design Conditions

    Directory of Open Access Journals (Sweden)

    K. W. Cheah

    2007-01-01

    Full Text Available The current investigation is aimed to simulate the complex internal flow in a centrifugal pump impeller with six twisted blades by using a three-dimensional Navier-Stokes code with a standard k-ε two-equation turbulence model. Different flow rates were specified at inlet boundary to predict the characteristics of the pump. A detailed analysis of the results at design load, Qdesign, and off-design conditions, Q = 0.43 Qdesign and Q = 1.45 Qdesign, is presented. From the numerical simulation, it shows that the impeller passage flow at design point is quite smooth and follows the curvature of the blade. However, flow separation is observed at the leading edge due to nontangential inflow condition. The flow pattern changed significantly inside the volute as well, with double vortical flow structures formed at cutwater and slowly evolved into a single vortical structure at the volute diffuser. For the pressure distribution, the pressure increases gradually along streamwise direction in the impeller passages. When the centrifugal pump is operating under off-design flow rate condition, unsteady flow developed in the impeller passage and the volute casing.

  2. TWO-DIMENSIONAL PARTICLE IMAGE VELOCIMETRY(PIV) MEASUREMENTS IN A TRANSPARENT CENTRIFUGAL PUMP

    Institute of Scientific and Technical Information of China (English)

    Yang Hua; Gu Chuangang; Wang Tong

    2005-01-01

    A special transparent centrifugal pump is designed. Detailed optical measurements of the flow inside the rotating passages of a five-bladed shroud centrifugal pump impeller have been performed by using two-dimensional particle image velocimetry (PIV). The flow is surveyed at three load conditions qv/qνd = 0.4, qν/qνd = 1.0, qν/qνd = 1.5, respectively. As a result, phase averaged PIV velocity vector maps on three planes between hub and shroud of the impeller are presented. At design load, the mean field of relative velocity is predominantly vane congruent, showing well-behaved flow without separation. The distributions of the relative velocity on different plane along the pump shaft are very different and there is always a low velocity zone near the pressure-side of the blade at both low and design flow rate, but the low-velocity-zone at the low flow rate is much larger than that at the design one. The study demonstrates that the PIV technique is efficient in providing reliable and detailed velocity data over a full impeller passage.

  3. Impact energy analysis of turbulent water sprays for continuous centrifugal concentration

    Institute of Scientific and Technical Information of China (English)

    PEN Nan-qi; CHEN Lu-zheng; XIONG Da-he

    2009-01-01

    A SLon full-scale continuous centrifugal concentrator was used to reconcentrate hematite from a high gradient magnetic separation concentrate to study the effect of impact angle, concentrate mass and drum rotation speed on the impact energy of turbulent water sprays for continuous centrifugal concentration, under conditions of feed volume flow rate around 9 m3/h, feed solid concentration of 25% - 35% and reciprocating velocity of water sprays at 0. 05 m/s. The results indicate that a mimmal critical impact energy is required in the water sprays for achieving continuous concentration of the concentrator; an unfitted impact angle reduces the impact ffciency, and the highest impact efficiency of 0. 6416 is found at the mpact angle of 60°; the increase in concentrate mass leads to an increase in impact energy, and the highest impact efficiency is maintained when the concentrate mass varies in the range of 0. 44 -0. 59 kg/s; when the concentrate mass and the pressure of water sprays are kept at around 0. 45 kg/s and in the range of 0. 4 -0. 6 MPa respectively, the impact energy increases proportionally with the increase of drum rotation speed.

  4. The carbon fiber development for uranium centrifuges: a Brazilian cooperative research

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Paulo Cesar Beltrao de, E-mail: p.queiroz@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil); Zouain, Desiree Moraes, E-mail: dmzouain@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    This paper analyzes both the carbon fiber-based development for uranium centrifuges and the research project that supports its development effort over time. The carbon fiber-based engineering properties make it a valuable supply for high technologic products. Nevertheless, its fabrication occurs only in few developed countries and there is no production in Brazil. In addition, the carbon fiber-based products have dual applications: they can be used by the civilian and military industry. Therefore, there are international restrictions related to its use and applications that justify the internal development. Moreover, the Brazilian Navy centrifuges for uranium enrichment were developed using carbon-fiber which contains polyacrylonitrile (PAN) as an imported raw material. The PAN properties of low weight, high tensile strength increase the isotopic separation efficiency. The Brazilian financial scenario surrounded by the international uncertain economy shows that combined creative project solutions are more effective. Therefore, the Navy's Technological Center in Sao Paulo (CTMSP), the University of Campinas (UNICAMP), the University of Sao Paulo (USP), the RADICIFIBRAS Company, and the Brazilian FINEP agency, which is responsible for the project financial support, established a partnership aiming the development of a domestic PAN-based carbon fiber industry. The innovative project solutions adopted and the results of this partnership are presented here. (author)

  5. A sedimentation study of graphene oxide in aqueous solution using gradient differential centrifugation.

    Science.gov (United States)

    Huang, Jing-Jing; Yuan, Yong J

    2016-04-28

    This work involved the study of sedimentation of graphene oxide (GO) in aqueous solution by gradient differential centrifugation. GO sheets of size varying from 400 nm to 1100 nm were separated with layer numbers ranging from 2-17. Semiquantitative analysis of FT-IR spectra was conducted based on statistical variance, in which relative oxidation and hydration degrees were numeralized. Combining XRD, optical microscopy and particle size measurements, the dominant effects of hydration and d-spacing on GO sediment in aqueous solution were observed. However, lateral particle shifting showed a relatively insignificant influence even though it has much larger effects on the GO weight compared with the GO thickness. Highly oxidized GO sheets were highly hydrated and had the tendency to face more severe resistance in aqueous sedimentation. Larger d-spacing allowed more water molecules to enter into interlayers and thus improved the degree of hydration, the lower density and the lower sedimentation velocity of GO sheets. However, fast sedimentation could be found in both large and small GO sheets due to the relatively non-dominant effect from lateral size shifting. The underlying mechanism was further probed by the mathematical modeling process. Our study reveals the potential limitations of current theory for explaining GO sedimentation and also demonstrates the effectiveness of gradient differential centrifugation for sorting GO sheets varying in hydration degree and thickness. PMID:27086748

  6. The carbon fiber development for uranium centrifuges: a Brazilian cooperative research

    International Nuclear Information System (INIS)

    This paper analyzes both the carbon fiber-based development for uranium centrifuges and the research project that supports its development effort over time. The carbon fiber-based engineering properties make it a valuable supply for high technologic products. Nevertheless, its fabrication occurs only in few developed countries and there is no production in Brazil. In addition, the carbon fiber-based products have dual applications: they can be used by the civilian and military industry. Therefore, there are international restrictions related to its use and applications that justify the internal development. Moreover, the Brazilian Navy centrifuges for uranium enrichment were developed using carbon-fiber which contains polyacrylonitrile (PAN) as an imported raw material. The PAN properties of low weight, high tensile strength increase the isotopic separation efficiency. The Brazilian financial scenario surrounded by the international uncertain economy shows that combined creative project solutions are more effective. Therefore, the Navy's Technological Center in Sao Paulo (CTMSP), the University of Campinas (UNICAMP), the University of Sao Paulo (USP), the RADICIFIBRAS Company, and the Brazilian FINEP agency, which is responsible for the project financial support, established a partnership aiming the development of a domestic PAN-based carbon fiber industry. The innovative project solutions adopted and the results of this partnership are presented here. (author)

  7. RESEARCH AND DEVELOPMENT OF AN INTEGRAL SEPARATOR FOR A CENTRIFUGAL GAS PROCESSING FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    LANCE HAYS

    2007-02-27

    A COMPACT GAS PROCESSING DEVICE WAS INVESTIGATED TO INCREASE GAS PRODUCTION FROM REMOTE, PREVIOUSLY UN-ECONOMIC RESOURCES. THE UNIT WAS TESTED ON AIR AND WATER AND WITH NATURAL GAS AND LIQUID. RESULTS ARE REPORTED WITH RECOMMENDATIONS FOR FUTURE WORK.

  8. Mechanism of Gas Intrusion into Molten Metal during Horizontal Centrifugal Casting

    Institute of Scientific and Technical Information of China (English)

    NI Feng; ZHANG Xhan-ling; YANG Di-xin; BI Xiao-qin; ZHANG Yong-zhen

    2004-01-01

    A mechanism of gas intrusion into molten metal during horizontal centrifugal casting was introduced .Based upon this concept, a special pouring method was suggested ,which can effectively prevent the pinhole defects in horizontal centrifugal castings.

  9. Effects of centrifugation stress on pituitary-gonadal function in male rats

    Science.gov (United States)

    Gray, G. D.; Smith, E. R.; Damassa, D. A.; Davidson, J. M.

    1980-01-01

    The effects of centrifugation for various lengths of time on circulating levels of luteinizing hormone (LH) and testosterone in male rats were investigated. In a chronic 52-day experiment, centrifugation at 4.1 G significantly reduced LH and testosterone levels for the entire period. Centrifugation at 2.3 G had less effect inasmuch as LH levels were not significantly decreased and testosterone levels were significantly reduced only during the first few days of centrifugation. In more acute experiments, centrifugation at 4.1 G for 4 h resulted in reduced testosterone levels, whereas centrifugation for 15 min did not significantly alter the hormone levels. These results indicate that centrifugation can decrease circulating LH and testosterone levels if the gravitational force is of sufficient magnitude and is maintained for a period of hours. Chronic centrifugation may also inhibit the acute excitatory response of LH to handling and ether stress.

  10. Dynamic actuator for Soil-Structure Interaction physical modelling in centrifuge

    OpenAIRE

    CABRERA, Miguel; Caicedo, Bernardo; THOREL, Luc

    2014-01-01

    Dynamic interactions in centrifuge modelling are often induced with external or not controlled sources. This paper presents a method to study Soil-Structure Interaction in centrifuge, with the use of a dynamic actuator developed for centrifuge testing. The dynamic actuator is employed into the model giving the possibility to test the dynamic response of a wind turbine structure, without any additional supporting accessory. The centrifuge soil model was instrumented in order to measure the wav...

  11. Extraction of cocoa proanthocyanidins and their fractionation by sequential centrifugal partition chromatography and gel permeation chromatography.

    Science.gov (United States)

    Pedan, Vasilisa; Fischer, Norbert; Rohn, Sascha

    2016-08-01

    Cocoa beans contain secondary metabolites ranging from simple alkaloids to complex polyphenols with most of them believed to possess significant health benefits. The increasing interest in these health effects has prompted the need to develop techniques for their extraction, fractionation, separation, and analysis. This work provides an update on analytical procedures with a focus on establishing a gentle extraction technique. Cocoa beans were finely ground to an average particle size of centrifugal partition chromatography (SCPC) and gel permeation column chromatography using Sephadex LH-20. For SCPC, a two-phase solvent system consisting of ethyl acetate/n-butanol/water (4:1:5, v/v/v) was successfully applied for the separation of theobromine, caffeine, and representatives of the two main phenolic compound classes flavan-3-ols and flavonols. Gel permeation chromatography on Sephadex LH-20 using a stepwise elution sequence with aqueous acetone has been shown for effectively separating individual flavan-3-ols. Separation was obtained for (-)-epicatechin, proanthocyanidin dimer B2, trimer C1, and tetramer cinnamtannin A2. The purity of alkaloids and phenolic compounds was determined by HPLC analysis and their chemical identity was confirmed by mass spectrometry.

  12. Centrifuge modeling of LNAPL transport in partially saturated sand

    NARCIS (Netherlands)

    Esposito, G.; Allersma, H.G.B.; Selvadurai, A.P.S.

    1999-01-01

    Model tests were performed at the Geotechnical Centrifuge Facility of Delft University of Technology, The Netherlands, to examine the mechanics of light nonaqueous phase liquid (LNAPL) movement in a partially saturated porous granular medium. The experiment simulated a 2D spill of LNAPL in an unsatu

  13. Centrifugal impeller operating at a very low temperature

    International Nuclear Information System (INIS)

    Several compression stages working at very low temperatures (approximately= 4 K) and low pressures (approximately= 10 mb) have been calculated, assembled and tested. Good thermodynamic efficiencies (approximately= 0,55) and compression ratios (approximately= 3) are obtained. A compression stage is constituted by a centrifugal impeller surrounded by a static diffuser

  14. Centrifugal Model Tests on Railway Embankments of Expansive Soils

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Based on the centrifugal model tests on railway embankments of expansive soil in Nanning-Kunming railway,the author studied several embankments under different physical conditions. The stress and strain states and settlement of the embankments were analyzed, and the obtained results can be used as a reference to field construction.

  15. Centrifuge modelling of rigid piles in soft clay

    DEFF Research Database (Denmark)

    Klinkvort, R.T.; Poder, M.; Truong, P.;

    2016-01-01

    of this study is to employ centrifuge modelling in order to derive experimental p-y curves for rigid piles embedded in over-consolidated soft clay. A kaolin clay sample was prepared and pre-consolidated by applying a constant pressure at the soil surface, while different over-consolidation ratios were achieved...

  16. Model Based Fault Detection in a Centrifugal Pump Application

    DEFF Research Database (Denmark)

    Kallesøe, Carsten; Cocquempot, Vincent; Izadi-Zamanabadi, Roozbeh

    2006-01-01

    A model based approach for fault detection in a centrifugal pump, driven by an induction motor, is proposed in this paper. The fault detection algorithm is derived using a combination of structural analysis, observer design and Analytical Redundancy Relation (ARR) design. Structural considerations...

  17. Liquid egg white pasteurization using a centrifugal UV irradiator

    Science.gov (United States)

    Studies are lacking on UV nonthermal pasteurization of liquid egg white (LEW). The objective of this study was to inactivate Escherichia coli using a UV irradiator that centrifugally formed a thin film of LEW on the inside of a rotating cylinder. The LEW was inoculated with E. coli K12 to approximat...

  18. DEMONSTRATION BULLETIN: THE PLASMA CENTRIFUGAL FURNACE RETECH, INC.

    Science.gov (United States)

    The plasma centrifugal furnace is a thermal technology which uses the heat generated from a plasma torch to decontaminate metal and organic contaminated waste. This is accomplished by melting metal-bearing solids and, in the process, thermally destroying organic contaminants. The...

  19. Pasteurization of grapefruit juice using a centrifugal ultraviolet light irradiator

    Science.gov (United States)

    The pharmaceutical industry uses UV irradiators to inactivate viruses in liquids without heat. The penetration depth of UV in some liquids, such as serum plasma, can be short. To overcome this, very thin films may be produced by centrifugal force, small diameter tubing, or other means. Many liquid f...

  20. Centrifugally driven microfluidic disc for detection of chromosomal translocations

    DEFF Research Database (Denmark)

    Brøgger, Anna Line; Kwasny, Dorota; Bosco, Filippo G.;

    2012-01-01

    and prognosis of patients. In this work we demonstrate a novel, centrifugally-driven microfluidic system for controlled manipulation of oligonucleotides and subsequent detection of chromosomal translocations. The device is fabricated in the form of a disc with capillary burst microvalves employed to control...

  1. Latex micro-balloon pumping in centrifugal microfluidic platforms.

    Science.gov (United States)

    Aeinehvand, Mohammad Mahdi; Ibrahim, Fatimah; Harun, Sulaiman Wadi; Al-Faqheri, Wisam; Thio, Tzer Hwai Gilbert; Kazemzadeh, Amin; Madou, Marc

    2014-03-01

    Centrifugal microfluidic platforms have emerged as point-of-care diagnostic tools. However, the unidirectional nature of the centrifugal force limits the available space for multi-step processes on a single microfluidic disc. To overcome this limitation, a passive pneumatic pumping method actuated at high rotational speeds has been previously proposed to pump liquid against the centrifugal force. In this paper, a novel micro-balloon pumping method that relies on elastic energy stored in a latex membrane is introduced. It operates at low rotational speeds and pumps a larger volume of liquid towards the centre of the disc. Two different micro-balloon pumping mechanisms have been designed to study the pump performance at a range of rotational frequencies from 0 to 1500 rpm. The behaviour of the micro-balloon pump on the centrifugal microfluidic platforms has been theoretically analysed and compared with the experimental data. The experimental data show that the developed pumping method dramatically decreases the required rotational speed to pump liquid compared to the previously developed pneumatic pumping methods. It also shows that within a range of rotational speed, a desirable volume of liquid can be stored and pumped by adjusting the size of the micro-balloon.

  2. Pasteurization of Grapefruit Juice using a Centrifugal Ultraviolet Light Device

    Science.gov (United States)

    The pharmaceutical industry uses UV devices to nonthermally inactivate viruses in liquids. To overcome the low penetration depth of UV in some liquids, such as serum plasma, thin films are formed by centrifugal force. Liquid foods also have low UV penetration depths. Studies are lacking on nontherma...

  3. Pressure Pulsation Signal Analysis for Centrifugal Compressor Blade Crack Determination

    Directory of Open Access Journals (Sweden)

    Hongkun Li

    2014-01-01

    Full Text Available Blade is a key piece of component for centrifugal compressor. But blade crack could usually occur as blade suffers from the effect of centrifugal forces, gas pressure, friction force, and so on. It could lead to blade failure and centrifugal compressor closing down. Therefore, it is important for blade crack early warning. It is difficult to determine blade crack as the information is weak. In this research, a pressure pulsation (PP sensor installed in vicinity to the crack area is used to determine blade crack according to blade vibration transfer process analysis. As it cannot show the blade crack information clearly, signal analysis and empirical mode decomposition (EMD are investigated for feature extraction and early warning. Firstly, signal filter is carried on PP signal around blade passing frequency (BPF based on working process analysis. Then, envelope analysis is carried on to filter the BPF. In the end, EMD is carried on to determine the characteristic frequency (CF for blade crack. Dynamic strain sensor is installed on the blade to determine the crack CF. Simulation and experimental investigation are carried on to verify the effectiveness of this method. The results show that this method can be helpful for blade crack classification for centrifugal compressors.

  4. Centrifugal pumping of gas-liquid mixtures: a mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Estevam, Valdir [PETROBRAS, Rio de Janeiro, RJ (Brazil); Franca, Fernando A. [Universidade Estadual de Campinas, SP (Brazil); Alhanati, Francisco J.S. [C-Fer Technologies, Edmonton, Alberta (Canada)

    2004-07-01

    Centrifugal pumps are known to show a 'surging' behavior at certain conditions of free gas and liquid flow rate at the intake. In the 'surging region' on a pump characteristic curve, the head generated is significantly lower than if the pump were handling a gas-liquid homogeneous mixture. The surging happens, as one shows in this paper, due to the existence of a gas pocket, referred as 'elongated bubble', at the pump impeller inlet region. Therefore, to be able to predict the performance of centrifugal pumps under two-phase conditions, one has to disclose and model the mechanisms that set existence of the elongated bubble at the impeller inlet, besides calculating its length inside the impeller. This paper reports on the results of experimental and mechanistic modelling work conducted with the objective of better predicting the gas-liquid performance of centrifugal pumps under all range of conditions, including those characterized by 'surging'. The focus was on small diameter centrifugal pumps used to produce oil wells. A mechanistic two-fluid model devised to calculate the head generated by the pump was developed. The predictions of the model show good agreement with data collected for this study, and with data recently collected by other research organizations. (author)

  5. The cavitation behavior with short length blades in centrifugal pump

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Quangnha; Lee, Chang Jin [Konkuk University, Seoul (Korea, Republic of)

    2010-10-15

    A CFD code with 2-D cascade model was developed to predict the cavitation behavior around the impeller blades of impeller in a centrifugal pump. The governing equations are the two-phase Reynolds Averaged Navier-Stokes equations in a homogeneous form in which both liquid and vapor phases are treated as incompressible fluid. To close the model, a standard k-{epsilon} turbulence model is introduced. And the mass transfer rates between liquid and vapor phases are implemented as well. The validations are carried out by comparing with reference data in impeller of a centrifugal pump impeller. The cavitation characteristics of current centrifugal pumps is tested at an on design point (V=8 m/s) and two off-design points (V=20 m/s and V=30 m/s), respectively. The criteria of cavitation and flow instability around blades are presented. The results show that the current centrifugal pump can safely operate without cavitation at on-design point. Also, the simulation shows cavitation develops inhomogeneously among the blades at off-design points. Moreover, the effects of additional blades in the impeller are studied as well. From the numerical results, it is expected that a half-length blade is the optimum configuration as additional blades in cavitation point of view

  6. Blade Crack Detection of Centrifugal Fan Using Adaptive Stochastic Resonance

    Directory of Open Access Journals (Sweden)

    Bingbing Hu

    2015-01-01

    Full Text Available Centrifugal fans are widely used in various industries as a kind of turbo machinery. Among the components of the centrifugal fan, the impeller is a key part because it is used to transform kinetic energy into pressure energy. Crack in impeller’s blades is one of the serious hidden dangers. It is important to detect the cracks in the blades as early as possible. Based on blade vibration signals, this research applies an adaptive stochastic resonance (ASR method to diagnose crack fault in centrifugal fan. The ASR method, which can utilize the optimization ability of the grid search method and adaptively realize the optimal stochastic resonance system matching input signals, may weaken the noise and highlight weak characteristic and thus can diagnose the fault accurately. A centrifugal fan test rig is established and experiments with three cases of blades are conducted. In comparison with the ensemble empirical mode decomposition (EEMD analysis and the traditional Fourier transform method, the experiment verified the effectiveness of the current method in blade crack detection.

  7. Prediction of performance of centrifugal pumps during starts under pressure

    Science.gov (United States)

    Rostafinski, W.

    1969-01-01

    Method which calculates start-up characteristics of centrifugal pumps reveals a capacity to predict pressure drop characteristics of pumps with vaned diffusers. Calculations are based on pump geometry, design-point flow, speed, and pressure rise, and the pump characteristic within range of approximately ten percent of the design-point flow.

  8. Measurements of the rotordynamic shroud forces for centrifugal pumps

    Science.gov (United States)

    Guinzburg, A.; Brennen, C. E.; Acosta, A. J.; Caughey, T. K.

    1990-01-01

    An experiment was designed to measure the rotordynamic shroud forces on a centrifugal pump impeller. The measurements were done for various whirl/impeller speed ratios and for different flow rates. A destabilizing tangential force was measured for small positive whirl ratios and this force decreased with increasing flow rate.

  9. Synthesis and Analytical Centrifugation of Magnetic Model Colloids

    NARCIS (Netherlands)

    Luigjes, B.

    2012-01-01

    This thesis is a study of the preparation and thermodynamic properties of magnetic colloids. First, two types of magnetic model colloids are investigated: composite colloids and single-domain nanoparticles. Thermodynamics of magnetic colloids is studied using analytical centrifugation, including a s

  10. Research on Three-Dimensional Unsteady Turbulent Flow in Multistage Centrifugal Pump and Performance Prediction Based on CFD

    Directory of Open Access Journals (Sweden)

    Zhi-jian Wang

    2013-01-01

    Full Text Available The three-dimensional flow physical model of any stage of the 20BZ4 multistage centrifugal pump is built which includes inlet region, impeller flow region, guide-vane flow region and exit region. The three-dimensional unsteady turbulent flow numerical model is created based on Navier-Stoke solver and standard k-ε turbulent equations. The method of multireference frame (MRF and SIMPLE algorithm are used to simulate the flow in multistage centrifugal pump based on FLUENT software. The distributions of relative velocity, absolute velocity, static pressure, and total pressure in guide vanes and impellers under design condition are analyzed. The simulation results show that the flow in impeller is mostly uniform, without eddy, backflow, and separation flow, and jet-wake phenomenon appears only along individual blades. There is secondary flow at blade end and exit of guide vane. Due to the different blade numbers of guide vane and impeller, the total pressure distribution is asymmetric. This paper also simulates the flow under different working conditions to predict the hydraulic performances of centrifugal pump and external characteristics including flow-lift, flow-shaft power, and flow-efficiency are attained. The simulation results are compared with the experimental results, and because of the mechanical losses and volume loss ignored, there is a little difference between them.

  11. Magnetic separator

    OpenAIRE

    Křupka, Jiří

    2015-01-01

    Cílem bakalářské práce je návrh konstrukčního řešení magnetického separátoru určeného k separaci drobného průmyslového odpadu. Tato zpráva obsahuje přehled zařízení světových výrobců, která slouží k magnetické separaci ocelového odpadu. Dále pak posouzení variant technických řešení konstrukčních uzlů magnetického separátoru a následný výběr konkrétního řešení. Dle vstupních parametrů jsou vypočteny všechny parametry potřebné ke správnému návrhu stroje. Ve výpočtech jsou zahrnuty i odůvodnění ...

  12. Enhancement of invasiveness of Yersinia enterocolitica and Escherichia coli in HEp-2 cells by centrifugation.

    OpenAIRE

    Vesikari, T; Bromirska, J; Mäki, M

    1982-01-01

    Centrifugation enhanced the infectivity of invasive Escherichia coli and Yersinia enterocolitica for HEp-2 cells. Noninvasive bacteria were not endocytosed after centrifugation. The centrifugation procedure may increase the sensitivity of testing for bacterial invasiveness in cell culture without causing false-positive results.

  13. Large-scale and highly efficient synthesis of micro- and nano-fibers with controlled fiber morphology by centrifugal jet spinning for tissue regeneration.

    Science.gov (United States)

    Ren, Liyun; Pandit, Vaibhav; Elkin, Joshua; Denman, Tyler; Cooper, James A; Kotha, Shiva P

    2013-03-21

    PLLA fibrous tissue scaffolds with controlled fiber nanoscale surface roughness are fabricated with a novel centrifugal jet spinning process. The centrifugal jet spinning technique is a highly efficient synthesis method for micron- to nano-sized fibers with a production rate up to 0.5 g min(-1). During the centrifugal jet spinning process, a polymer solution jet is stretched by the centrifugal force of a rotating chamber. By engineering the rheological properties of the polymer solution, solvent evaporation rate and centrifugal force that are applied on the solution jet, polyvinylpyrrolidone (PVP) and poly(l-lactic acid) (PLLA) composite fibers with various diameters are fabricated. Viscosity measurements of polymer solutions allowed us to determine critical polymer chain entanglement limits that allow the generation of continuous fiber as opposed to beads or beaded fibers. Above a critical concentration at which polymer chains are partially or fully entangled, lower polymer concentrations and higher centrifugal forces resulted in thinner fibers. Etching of PVP from the PLLA-PVP composite fibers doped with increasing PVP concentrations yielded PLLA fibers with increasing nano-scale surface roughness and porosity, which increased the fiber hydrophilicity dramatically. Scanning electron micrographs of the etched composite fibers suggest that PVP and PLLA were co-contiguously phase separated within the composite fibers during spinning and nano-scale roughness features were created after the partial etching of PVP. To study the tissue regeneration efficacy of the engineered PLLA fiber matrix, human dermal fibroblasts are used to simulate partial skin graft. Fibers with increased PLLA surface roughness and porosity demonstrated a trend towards higher cell attachment and proliferation.

  14. Gas Separation in the Ranque-Hilsch Vortex tube

    DEFF Research Database (Denmark)

    Linderstrøm-Lang, C. U.

    1964-01-01

    The gas separation taking place in the vortex tube is studied in detail. Both enrichment and depletion of a given component in any one of the two resultant streams may take place; the sign of this separation effect depends on certain parameters, notably the hot to cold flow ratio. A comparison of...... is reached that the centrifugation of the air, and only that, creates the gas separation detected in the outgoing streams. Its relation to the well-known temperature difference also produced between the two streams, is discussed. A flow scheme involving the radial and axial flow components, which...

  15. Comparative analysis of discrete exosome fractions obtained by differential centrifugation

    Directory of Open Access Journals (Sweden)

    Dennis K. Jeppesen

    2014-11-01

    Full Text Available Background: Cells release a mixture of extracellular vesicles, amongst these exosomes, that differ in size, density and composition. The standard isolation method for exosomes is centrifugation of fluid samples, typically at 100,000×g or above. Knowledge of the effect of discrete ultracentrifugation speeds on the purification from different cell types, however, is limited. Methods: We examined the effect of applying differential centrifugation g-forces ranging from 33,000×g to 200,000×g on exosome yield and purity, using 2 unrelated human cell lines, embryonic kidney HEK293 cells and bladder carcinoma FL3 cells. The fractions were evaluated by nanoparticle tracking analysis (NTA, total protein quantification and immunoblotting for CD81, TSG101, syntenin, VDAC1 and calreticulin. Results: NTA revealed the lowest background particle count in Dulbecco's Modified Eagle's Medium media devoid of phenol red and cleared by 200,000×g overnight centrifugation. The centrifugation tube fill level impacted the sedimentation efficacy. Comparative analysis by NTA, protein quantification, and detection of exosomal and contamination markers identified differences in vesicle size, concentration and composition of the obtained fractions. In addition, HEK293 and FL3 vesicles displayed marked differences in sedimentation characteristics. Exosomes were pelleted already at 33,000×g, a g-force which also removed most contaminating microsomes. Optimal vesicle-to-protein yield was obtained at 67,000×g for HEK293 cells but 100,000×g for FL3 cells. Relative expression of exosomal markers (TSG101, CD81, syntenin suggested presence of exosome subpopulations with variable sedimentation characteristics. Conclusions: Specific g-force/k factor usage during differential centrifugation greatly influences the purity and yield of exosomes. The vesicle sedimentation profile differed between the 2 cell lines.

  16. A Review of Experimental And Theoretical Investigations of Stable Isotope Separation by Plasma Methods

    International Nuclear Information System (INIS)

    Here is given a review of experimental and theoretical investigations of isotope separation processes in different plasma separation devices: plasma centrifuges, RF-systems with traveling magnetic field, DC arc discharges, nonequilibrium plasmachemical reactions (diffusion methods), and also in ICR-installations, performing isotopically selective ion-cyclotron resonance heating of the target component in magnetized collisionless plasma (selective collisionless method). Applied to separation installations, with the use of diffusion processes, various cardinal mechanisms are considered, leading to separation phenomena in plasma: centrifuging, thermodiffusion, ion wind, difference of isotope ionization degree, etc. Comparison is performed with the results of experiments. Problems of metal isotope separation by method of isotopically selective ion cyclotron resonance (ICR) are considered. Estimations of energetic consumption in all plasma methods of isotope separation and possibility of their industrial use are given. (author)

  17. Centrifugal partition chromatography as a tool for preparative purification of pea albumin with enhanced yields.

    Science.gov (United States)

    Bérot, Serge; Le Goff, Elisabeth; Foucault, Alain; Quillien, Laurence

    2007-01-15

    A new procedure including the use of centrifugal partition chromatography (CPC) is proposed to purify PA1b and its isoforms. These pea (Pisum sativum L.) seed proteins are toxic against weevils and can be used as an environment-friendly insecticide. CPC was applied to a whole albumin fraction prepared from pea flour. The butanol:aqueous TFA system used in CPC allowed the separation of PA1b from other albumins and a degree of purification above 95%. Compared to analytical procedures based on methanol extraction, anion exchange and then reversed-phase chromatography (RPC), CPC recovered PA1b in much better yield, which is indispensable for large-scale purification of a biodegradable insecticide.

  18. Market of stable isotopes produced by gas centrifuges: status and prospects

    International Nuclear Information System (INIS)

    The major consumers on the market of enriched stable isotopes traditionally include nuclear industry, medicine and life sciences, and new technical and scientific applications. The beginning of new millennium has brought the wide application of enriched stable isotopes in fundamental physics experiments that needed tens and hundreds kilograms of various stable isotopes of middle and heavy masses. In addition, the needs of nuclear power industry to develop materials to be used in nuclear power plants capable to reduce formation of radioactive by-products and to prevent cracking in certain metallic components led to production of big amounts of different compounds of zinc depleted with the 64Zn isotope. All these problems have been solved successfully by means of the gas centrifuge technology applied for separation of isotopes other than uranium. As a result the market of enriched/depleted stable isotopes has changed radically in recent years. (authors)

  19. Investigation of the Stage Performance and Flow Fields in a Centrifugal Compressor with a Vaneless Diffuser

    Directory of Open Access Journals (Sweden)

    Ahti Jaatinen-Värri

    2014-01-01

    Full Text Available The effect of the width of the vaneless diffuser on the stage performance and flow fields of a centrifugal compressor is studied numerically and experimentally. The diffuser width is varied by reducing the diffuser flow area from the shroud side (i.e., pinching the diffuser. Seven different diffuser widths are studied with numerical simulation. In the modeling, the diffuser width b/b2 is varied within the range 1.00 to 0.50. The numerical results are compared with results obtained in previous studies. In addition, two of the diffusers are further investigated with experimental measurement. The main finding of the work is that the pinch reduces losses in the impeller associated with the tip-clearance flow. Furthermore, it is shown that a too large width reduction causes the flow to accelerate excessively, resulting in a highly nonuniform flow field and flow separation near the shroud.

  20. Investigation of flow dynamics and decrease of vortex noise inside volute of centrifugal fans

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The characteristics of three-dimension flow dynamics inside the volute of a G4-73No.8D centrifugal fan was simulated numerically using a computational fluid dynamics(CFD) technique.The generation,evolution,and noise of the vortex were investigated when cylinder-shaped and cone-cylinder-shaped anti-vortex rings were added separately.Numerical results showed that large-scale vortices were broken effectively and the flow fields inside the fan were more uniform with the two anti-vortex rings installed.Experimental results indicated A-sound level and spectrum noise of the refitted fan decreased and the two anti-vortex rings were effective in decreasing vortex noise.The cone-cylinder-shaped anti-vortex ring was more effective than the cylinder-shaped one in breaking largescale vortexes and decreasing vortex noise.

  1. A study of ceramic-lined composite steel pipes prepared by SHS centrifugal-thermite process

    Directory of Open Access Journals (Sweden)

    Li Yuxin

    2016-01-01

    Full Text Available Al2O3 ceramic-lined steel pipe was produced by self-propagating high-temperature synthesis centrifugal thermite process (SHS C-T process from Fe2O3 and Al as the raw materials. The composition, phase separation and microstructures were investigated. The result showed the ceramic lined pipe is composed of the three main layers of various compositions, which were subsequently determined to be Fe layer, the transition layer and the ceramic layer. Fe layer is composed of austenite and ferrite, the transition layer consisted of Al2O3 ceramic and Fe, the ceramic layer consisted of the dendritic-shaped Al2O3 and the spinel-shaped structured FeAl2O4.

  2. EFFECTS OF SPLITTER BLADES ON THE LAW OF INNER FLOW WITHIN CENTRIFUGAL PUMP IMPELLER

    Institute of Scientific and Technical Information of China (English)

    YUAN Shouqi; ZHANG Jinfeng; YUAN Jianping; HE Youshi; FU Yuedeng

    2007-01-01

    Analysis on the inner flow field of a centrifugal pump impeller with splitter blades is carried out by numerical simulation. Based on this analysis, the principle of increasing pump head and efficiency are discussed. New results are obtained from the analysis of turbulence kinetic energy and relative velocity distribution: Firstly, unreasonable length or deviation design of the splitter blades may cause great turbulent fluctuation in impeller channel, which has a great effect on the stability of impeller outlet flow; Secondly, it is found that the occurrence of flow separation can be decreased or delayed with splitter blades from the analysis of blade loading; Thirdly, the effect of splitter blades on reforming the structure of "jet-wake" is explained from the relative velocity distribution at different flow cross-sections, which shows the flow process in the impeller. The inner flow analysis verifies the results of performance tests results and the PIV test.

  3. Performance Enhancement of Dual-Inlet Centrifugal Blower by Optimal Design of Splitter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Sung; Jang, Choon Man [Korea Institute of Construction Technology, Goyang (Korea, Republic of)

    2014-12-15

    The shape of an impeller splitter for a dual-inlet centrifugal blower was optimized to enhance the blower performance. Two design variable, the normalized chord and pitch of a splitter, were used to evaluate the blower performance and internal flow fields based on the three-dimensional flow analysis. The blower performance obtained using this numerical simulation had a maximum error of 4 percent compared to that in an experiment at the design flow condition. The shape optimization of the splitter successfully increased the blower efficiency and pressure by 3.65 and 1.14 percent compared to the reference values. The blower performance was increased by reducing the flow separation near the blade suction surface by optimizing the shape of the splitter, which produced a pressure increase at the outlet of the volute casing.

  4. Characteristics of centrifugal pumps handling air-water mixtures and size of air bubbles in pump impellers

    International Nuclear Information System (INIS)

    Characteristics of centrifugal pumps handling air-water mixtures are analyzed on the basis of a gas-liquid separated flow model, which is generally accepted in the analysis of the data on a two-phase flow in piping systems. And a method for predicting the pump characteristics is presented with use of parameters of friction-loss and shock-loss multipliers. Size of air bubbles flowing through pump impellers was measured. The bubbles in the inlet region of the impellers have an extremely uniform size with fairly small diameters. But in course of flow, the bubble diameter grows gradually due to coalescence of the bubbles. (author)

  5. The enhanced ASDEX Upgrade pellet centrifuge launcher

    Science.gov (United States)

    Plöckl, B.; Lang, P. T.

    2013-10-01

    Pellets played an important role in the program of ASDEX Upgrade serving both for investigations on efficient particle fuelling and high density scenarios but also for pioneering work on Edge Localised Mode (ELM) pacing and mitigation. Initially designed for launching fuelling pellets from the magnetic low field side, the system was converted already some time ago to inject pellets from the magnetic high field side as much higher fuelling efficiency was found using this configuration. In operation for more than 20 years, the pellet launching system had to undergo a major revision and upgrading, in particular of its control system. Furthermore, the control system installed adjacent to the launcher had to be transferred to a more distant location enforcing a complete galvanic separation from torus potential and a fully remote control solution. Changing from a hybrid system consisting of PLC S5/S7 and some hard wired relay control to a state of the art PLC system allowed the introduction of several new operational options enabling more flexibility in the pellet experiments. This article describes the new system architecture of control hardware and software, the operating procedure, and the extended operational window. First successful applications for ELM pacing and triggering studies are presented as well as utilization for the development of high density scenarios.

  6. CENTRIFUGAL PUMP AND SHAFT SEALING MEANS

    Science.gov (United States)

    Rushing, F.C.

    1960-09-01

    A description is given of sealing means between a hollow rotatable shaft and a stationary member surrounding the shaft which defines therewith a sealing space of annular cross-section, comprising a plurality of axially spaced rings held against seats by ring springs which serve to subdivide the sealing space- into a plurality of zones. Process gas introduced into the hollow shaft through a port communicating with a centrally located zone which iu turn communicates with a bore in the sleeve, is removed from the shaft through a second port communicating with an adjacent central zone and discharged through a second bore. A sealant gas is supplied to an end zone under a pressure sufficient to cause it to flow axially into adjacent zones and then maintained at a lower pressure than either the sealant gas source or the process gas inlet zone, preventing the sealant gas from entering the shaft and allowing gases leaking into the sealant gas to be withdrawn and led to a separator.

  7. Environmental and centrifugal factors influencing the visco-elastic properties of oral biofilms in vitro.

    Science.gov (United States)

    Peterson, Brandon W; Busscher, Henk J; Sharma, Prashant K; van der Mei, Henny C

    2012-01-01

    Centrifugal compaction causes changes in the surface properties of bacterial cells. It has been shown previously that the surface properties of planktonic cells change with increasing centrifugal compaction. This study aimed to analyze the influences of centrifugal compaction and environmental conditions on the visco-elastic properties of oral biofilms. Biofilms were grown out of a layer of initially adhering streptococci, actinomyces or a combination of these. Different uni-axial deformations were induced on the biofilms and the load relaxations were measured over time. Linear-Regression-Analysis demonstrated that both the centrifugation coefficient for streptococci and induced deformation influenced the percentage relaxation. Centrifugal compaction significantly influenced relaxation only upon compression of the outermost 20% of the biofilm (p centrifugal compaction of initially adhering, centrifuged bacteria extend to the visco-elastic properties of biofilms, indicating that the initial bacterial layer influences the structure of the entire biofilm.

  8. Centrifugal partition chromatography elution gradient for isolation of sesquiterpene lactones and flavonoids from Anvillea radiata.

    Science.gov (United States)

    Destandau, Emilie; Boukhris, Meryem Alaoui; Zubrzycki, Sandrine; Akssira, Mohamed; Rhaffari, Lhoucine El; Elfakir, Claire

    2015-03-15

    An innovative procedure coupling pressurized solvent extraction and centrifugal partition chromatography (CPC) used in linear gradient elution mode was developed to isolate two pure germacranolides (9α-hydroxyparthenolide and 9β-hydroxyparthenolide) and to separate flavonoids (nepetin, isorhamnetin and jaceosidin) and chlorophyll pigments from aerial parts of Anvillea radiata (Coss.&Durieu). The two main germacranolides recovered using this method represent 2 and 5% of the dried plant material respectively. These molecules were extracted using accelerated solvent extraction with chloroform. After optimization of the CPC method, a two-phase solvent system composed of heptane/ethyl acetate/methanol/water (1:5:1:5 v/v/v/v) was employed in descending mode to isolate the germacranolides. Then the lower phase of a heptane/ethyl acetate/methanol/water (6:5:6:5 v/v/v/v) system was pumped in descending mode to generate a linear elution gradient, progressively decreasing the mobile phase polarity, that enabled the flavonoid compounds to be separated in the same run. The efficiency of the preparative separation was controlled through RP-HPLC analysis of the obtained fractions using UV, evaporative light scattering and mass spectrometry detection. The structural identification of the two germacranolides purified over 99% was established by (1)H NMR and (13)C NMR. The least abundant flavonoids were identified by mass spectrometry. PMID:25647341

  9. Numerical Study of Centrifugal Compressor with Slots in Blade Surface%高速离心叶轮叶片开缝的数值研究

    Institute of Scientific and Technical Information of China (English)

    韩伟; 高丽敏; 白莹; 李晓军; 高杰

    2011-01-01

    提出在离心叶轮吸力面尾部开缝抽吸的方法,在叶片吸力面尾部对低速流体区域进行抽吸,以减弱由叶轮内二次流所导致的射流—尾迹结构.以Krain高速离心叶轮为例,建立抽吸模型,并进行了数值计算.数值仿真结果表明,在压气机流量范围内,叶轮尾部开缝抽吸可以减少叶片表面的分离区域,改善叶轮内部流场的流动状况,有效地提高离心叶轮性能.%A new method of drilling through-slots in blade suction surfaces near the shroud of a centrifugal impeller is proposed, where low velocity area or separation area is sucked ,as a result,the jet-wake flow caused by secondary flows in the impeller is weakened. The numerical model of Krain centrifugal impeller is built and computed. The result show that the seperation area near blade suction surfaces is reduced , the flow field inside centrifugal impeller is improved and better performance of the centrifugal impeller can be achieved by sucking from slots in suction surfaces.

  10. Analysis of cantilever NEMS in centrifugal-fluidic systems

    Science.gov (United States)

    Mohsen-Nia, Mohsen; Abadian, Fateme; Abadian, Naeime; Dehkordi, Keivan Mosaiebi; Keivani, Maryam; Abadyan, Mohamadreza

    2016-07-01

    Electromechanical nanocantilevers are promising for using as sensors/detectors in centrifugal-fluidic systems. For this application, the presence of angular speed and electrolyte environment should be considered in the theoretical analysis. Herein, the pull-in instability of the nanocantilever incorporating the effects of angular velocity and liquid media is investigated using a size-dependent continuum theory. Using d’Alembert principle, the angular speed is transformed into an equivalent centrifugal force. The electrochemical and dispersion forces are incorporated considering the corrections due to the presence of electrolyte media. Two different approaches, i.e., the Rayleigh-Ritz method (RRM) and proposing a lumped parameter model (LPM), were applied to analyze the system. The models are validated with the results presented in literature. Impacts of the angular velocity, electrolyte media, dispersion forces, and size effect on the instability characteristics of the nanocantilever are discussed.

  11. Considerations in designing a centrifugal atomiser for metal powder production

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.Y. [Department of Engineering, The University of Liverpool, Liverpool L69 3GH (United Kingdom)]. E-mail: y.y.zhao@livepool.ac.uk

    2006-07-01

    In centrifugal atomisation for metal powder production, the key to the control of the particle sizes is the design of the atomiser. This paper studies the main issues concerned in designing a centrifugal atomiser and provides guidance on the selection of an electric motor, radius of atomiser, slope angle of atomiser wall and flow rate of cooling water. In the selection of the atomiser radius, the power and material constraints as well as the hydraulic jump radius need to be considered. A cup atomiser with a slope angle of 60-70{sup o} would result in small spray droplets and thus a fine powder. The water cooling system needs to be assessed by examining the heat flow in the solid metal layer and in the atomiser.

  12. Concept for a short arm human centrifuge onbord ISS.

    Science.gov (United States)

    Kuebler, Ulrich; Grinberg, Anna; Kern, Peter

    Astrium is presently performing for ESA a definition study about the accommodation of a short arm human centrfiuge into a spacecraft. A scientific workshop has been part of the study with the goal to define from various research fields (e.g. cardiovascular, gravitational biology, neuroscience, bone/muscle) requirements for such an artificial gravity system on ISS. As a second step the requirements were consolidated to a set of common specfications for the developemnt of a centrifuge system serving as integrated countermeasure for longterm exposure to g. The presentation will focus on the scientific requirements and the respective translation into technical requirement, finally leading to a centrifuge concept, including accommodation possi-bilities onbord ISS.

  13. Centrifuge modeling of PGD response of buried pipe

    Institute of Scientific and Technical Information of China (English)

    Michael O'Rourke; Vikram Gadicherla; Tarek Abdoun

    2005-01-01

    A new centrifuge based method for determining the response of continuous buried pipe to PGD is presented.The physical characteristics of the RPI's 100 g-ton geotechnical centrifuge and the current lifeline experiment split-box are described: The split-box contains the model pipeline and surrounding soil and is manufactured such that half can be offset, in flight, simulating PGD. In addition, governing similitude relations which allow one to determine the physical characteristics,(diameter, wall thickness and material modulus of elasticity) of the model pipeline are presented. Finally, recorded strains induced in two buried pipes with prototype diameters of 0.63 m and 0.95 m (24 and 36 inch) subject to 0.6 and 2.0 meters (2and 6 feet) of full scale fault offsets and presented and compared to corresponding FE results.

  14. Stage-efficiency of centrifugal extractor used in nuclear industry

    Institute of Scientific and Technical Information of China (English)

    吴秋林; 景山; 王兴海; 宋崇立

    2003-01-01

    The stage-efficiency of a single-stage prototype (d70) centrifugal extractor and the cascade is tested by HNO3-Nd3+ and 30%TRPO-kerosene system. The experimental results of the single-stage centrifugal extractor show that the carryover of the two phases decreases with increasing ratio of the two flow rate and rotation rate and the stage efficiency increases with not only decreasing total flow rate but also increasing rotor speed. However, the experimental results of the cascade show that the average stage efficiency of the cascade increases with not only decreasing total flow rate but also increasing rotor speed in both three-stage mode and two-stage mode.

  15. Massively parallel single-molecule manipulation using centrifugal force

    CERN Document Server

    Halvorsen, Ken

    2009-01-01

    Precise manipulation of single molecules has already led to remarkable insights in physics, chemistry, biology and medicine. However, widespread adoption of single-molecule techniques has been impeded by equipment cost and the laborious nature of making measurements one molecule at a time. We have solved these issues with a new approach: massively parallel single-molecule force measurements using centrifugal force. This approach is realized in a novel instrument that we call the Centrifuge Force Microscope (CFM), in which objects in an orbiting sample are subjected to a calibration-free, macroscopically uniform force-field while their micro-to-nanoscopic motions are observed. We demonstrate high-throughput single-molecule force spectroscopy with this technique by performing thousands of rupture experiments in parallel, characterizing force-dependent unbinding kinetics of an antibody-antigen pair in minutes rather than days. Additionally, we verify the force accuracy of the instrument by measuring the well-est...

  16. Flow generation in a novel centrifugal diffuser test device

    Science.gov (United States)

    Vidos, P.

    1983-09-01

    Recognition of the need to develop optimum diffusers for advanced centrifugal compressors, resulted in the design and manufacture of a novel low-speed test facility for centrifugal diffuser testing. The CDTD was designed to allow the flow angle and wall boundary profiles into the test diffuser to be controlled by variable geometry in the flow generator. The present study reports on the design of the flow generator and the analysis of the internal flow using a NASA computer code (MERIDL). First test results are given and are compared with the results of a control volume analysis. The flow angle control technique was found to work effectively but to give somewhat smaller angles (by 4 deg) than were predicted. It was concluded that the information obtained would allow scaling of the device; however, an analysis code was needed which would accept the real physical boundary conditions.

  17. A centrifugal pump concept designed for multiple use in space

    Science.gov (United States)

    Wunderlich, E.; Wulz, H. G.

    A centrifugal pump concept was elaborated for a multiple application in future spacecrafts. Based on this concept a prototype of a small centrifugal pump was manufactured and comprehensively tested. The model pump has been approved in different test series with the fluids liquid ammonia and demineralized water. The design of the model pump was driven by strict requirements of COLUMBUS, namely long life, noiseless operation, minimum mass and low energy consumption. Because of its modular design and as a result of selected materials of multiple compatibility, this pump is suited for the delivery of various further fluids, such as freons, hydrocarbons, propellants (hydrazine) etc.. It is also capable of pumping corrosive or toxic fluids for laboratory processes in space. The wide speed range from about 1,00 to 20,000 rpm which corresponds to a flow from about 1 to 20 l/min, permits an energy saving adaption and flow control.

  18. Dynamical System Analysis of Unsteady Phenomena in Centrifugal Compressor

    Institute of Scientific and Technical Information of China (English)

    YasuyukiKomatsubara; ShimpeiMizuki

    1997-01-01

    Surge and rotating stall occurring in a centrifugal compressor system are investigated by using a phase portrait reconstruction method.From experimentally measured time series of data,the method clarified the cyclic behavior of surge.For rotating stall,there still remain problems in the phase portrait due to the chaotic behavior.However,the results obtained by the present method are able to provide new insights to the modelings for surge and rotating stall.Surge and roatting stall occurring in a centrifugal compressor system are investigated by using a phase portrait reconstruction method.From experimentally measured time series of data,the method clarified the cylcic behavior of surge.For rotating stall,there still remain problems in the phase portrait due to the chaotic behavior.However,the results obtained by the present method are able to provide new insights to the modelings for surge and rotating stall.

  19. Optimization of centrifugal pump cavitation performance based on CFD

    Science.gov (United States)

    Xie, S. F.; Wang, Y.; Liu, Z. C.; Zhu, Z. T.; Ning, C.; Zhao, L. F.

    2015-01-01

    In order to further improve the cavitation performance of a centrifugal pump, slots on impeller blade near inlet were studied and six groups of hydraulic model were designed. Base on cavitating flow feature inside a centrifugal pump, bubble growth and implosion are calculated from the Rayleigh-Plesset equation which describes the dynamic behavior of spherical bubble and RNG κ-epsilon model was employed to simulate and analyze the internal two-phase flow of the model pump under the same conditions. The simulation results show that slots on blade near inlet could improve the cavitation performance and cavitation performance improvement of the second group was more obvious. Under the same conditions, the pressure on the back of blade near inlet was higher than the pressure on the back of unmodified blade near inlet, and energy distribution in the flow channel between the two blades was more uniform with a small change of head.

  20. Centrifuge Modeling of Piles Subjected to Lateral Loads

    Science.gov (United States)

    Brant, Logan; Ling, Hoe I.

    There are many applications where piles are employed to absorb and deflect lateral impact loads. Structural elements of this type are used to protect infrastructure and are commonly found at marine sites. A series of model tests have been conducted using Columbia University's centrifuge facility to better understand the performance of piles subjected to these loading conditions. A device was designed to install and laterally load single model piles during centrifuge flight. This device uniquely contains two lateral loading systems, one which allows static testing and another appropriate for dynamic tests. This research examines the behavior of tubular steel piles embedded within dry or saturated soil and subjected to varied rates of lateral loading. This investigation provides insight on the contribution of lateral loading rates to the behavior of piles.

  1. Dynamic Actuator for Centrifuge Modeling of Soil-Structure Interaction

    OpenAIRE

    CABRERA, Miguel Angel; Caicedo, Bernardo; THOREL, Luc

    2012-01-01

    This paper presents a new dynamic actuator useful to study soil-structure interactions in a centrifuge. This new dynamic apparatus is based on an amplified piezoelectric actuator. Using this device it is possible to create vibrations in the soil sample of different frequencies and amplitudes. The dynamic actuator consists of a set of weights in a single degree of freedom system plus a piezoelectric actuator and a piezoelectric load cell, which measures the dynamic load. A description of the d...

  2. Centrifuge modeling of soil atmosphere interaction using climatic chamber

    OpenAIRE

    CAICEDO, B; TRISTANCHO, J; THOREL, Luc

    2010-01-01

    Soil-atmospheric interaction processes such as infiltration or evaporation can have a significant effect on the behavior of geotechnical structures located near the soil surface. This paper focuses on the drying process of soils due to evaporation. The scaling laws are analyzed and the results of the application of two cycles of heating and cooling on a soil mass are presented. Based on these results, conclusions about the feasibility of reproducing evaporation on centrifuge models are recomm...

  3. Origins of hydrodynamic forces on centrifugal pump impellers

    OpenAIRE

    Adkins, Douglas R.; Brennen, Christopher E.

    1986-01-01

    Hydrodynamic interactions that occur between a centrifugal pump impeller and volute are experimentally and theoretically investigated. The theoretical analysis considers the inability of the blades to perfectly guide the flow through the impeller, and also includes a quasi-one dimensional treatment of the flow in the volute. The disturbance at the impeller discharge and the resulting forces are determined by the theoretical model. The model is then extended to obtain the hydrodynamic force pe...

  4. Analyses of Hydrodynamic Radial Forces on Centrifugal Pump Impellers

    OpenAIRE

    Adkins, D. R.; Brennen, C. E.

    1988-01-01

    Hydrodynamic interactions that occur between a centrifugal pump impeller and a volute are experimentally and theoretically investigates. The theoretical analysis considers the inability of the blades to perfectly guide the flow through the impeller, and also includes a quasi-one dimensional treatment of flow in the volute. Flow disturbances at the impeller discharge and the resulting forces are determined by the theoretical model. The model is then extended to obtain the hydrodynamic force...

  5. Computational and Experimental Study of an Industrial Centrifugal Compressor Volute

    Institute of Scientific and Technical Information of China (English)

    HarriPitkanen; HannuEsa; 等

    2000-01-01

    A centrifugal compressor with a vaneless diffuser was studied experimentally and numericallly.The main target of the study was to analyze the volute flow.Two different volute geometries was studied.The numerical solution was done by using a steady-state RANS code at both design and off-design conditions.Both calculated and measured pressure and velocity distributions are presented.

  6. Centrifugal stretching of 170Hf in the interacting boson model

    Directory of Open Access Journals (Sweden)

    Werner V.

    2014-03-01

    Full Text Available We present the results of a recent experiment to deduce lifetimes of members of the ground state rotational band of 170Hf, which show the effect of centrifugal stretching in this deformed isotope. Results are compared to the geometrical confined beta-soft(CBS rotor model, as well as to the interacting boson model (IBM. Two methods to correct for effects due to the finite valence space within the IBM are proposed.

  7. Purification of crime scene DNA extracts using centrifugal filter devices

    OpenAIRE

    Norén, Lina; Hedell, Ronny; Ansell, Ricky; Hedman, Johannes

    2013-01-01

    BACKGROUND: The success of forensic DNA analysis is limited by the size, quality and purity of biological evidence found at crime scenes. Sample impurities can inhibit PCR, resulting in partial or negative DNA profiles. Various DNA purification methods are applied to remove impurities, for example, employing centrifugal filter devices. However, irrespective of method, DNA purification leads to DNA loss. Here we evaluate the filter devices Amicon Ultra 30 K and Microsep 30 K with respect to re...

  8. A Review of Centrifugal Testing of Gasoline Contamination and Remediation

    OpenAIRE

    Jay N. Meegoda; Liming Hu

    2011-01-01

    Leaking underground storage tanks (USTs) containing gasoline represent a significant public health hazard. Virtually undetectable to the UST owner, gasoline leaks can contaminate groundwater supplies. In order to develop remediation plans one must know the extent of gasoline contamination. Centrifugal simulations showed that in silty and sandy soils gasoline moved due to the physical process of advection and was retained as a pool of free products above the water table. However, in clayey soi...

  9. Development and Design of a Centrifugal Compressor Volute

    OpenAIRE

    Cheng Xu; Michael Müller

    2005-01-01

    The volute is one of the key components of a centrifugal compressor. The design of the volute not only impacts the compressor efficiency but also influences the operating range. The detailed flow simulation presented here helps to better understand the volute flow mechanisms and provide design guidance in volute design to meet performance goals. In this study, the viscous Navier-Stokes equations are used to simulate the flow inside the vaneless diffuser and volute. The de...

  10. Inverse Design of Centrifugal Compressor Stages Using a Meanline Approach

    OpenAIRE

    Yuri Biba; Peter Menegay

    2004-01-01

    This article discusses an approach for determining meanline geometric parameters of centrifugal compressor stages given specified performance requirements. This is commonly known as the inverse design approach. The opposite process, that of calculating performance parameters based on geometry input is usually called analysis, or direct calculation. An algorithm and computer code implementing the inverse approach is described. As an alternative to commercially available inverse design codes...

  11. A Novel Aerodynamic Design Method for Centrifugal Compressor Impeller

    OpenAIRE

    Mahdi Nili-Ahmadabadi; mohammad durali; Ali Hajilouy Benisi

    2014-01-01

    This paper describes a new quasi-3D design method for centrifugal compressor impeller. The method links up a novel inverse design algorithm, called Ball-Spine Algorithm (BSA), and a quasi-3D analysis. Euler equation is solved on the impeller meridional plane. The unknown boundaries (hub and shroud) of numerical domain are iteratively modified by BSA until a target pressure distribution in flow passage is reached. To validate the quasi-3D analysis code, existing compressor impeller is investig...

  12. Optimal Design of a Centrifugal Compressor Impeller Using Evolutionary Algorithms

    OpenAIRE

    Soo-Yong Cho; Kook-Young Ahn; Young-Duk Lee; Young-Cheol Kim

    2012-01-01

    An optimization study was conducted on a centrifugal compressor. Eight design variables were chosen from the control points for the Bezier curves which widely influenced the geometric variation; four design variables were selected to optimize the flow passage between the hub and the shroud, and other four design variables were used to improve the performance of the impeller blade. As an optimization algorithm, an artificial neural network (ANN) was adopted. Initially, the design of experiment...

  13. Centrifugal compressor flow instabilities at lowmass flow rate

    OpenAIRE

    Sundström, Elias

    2016-01-01

    Turbochargers play an important role in increasing the energetic efficiency andreducing emissions of modern power-train systems based on downsized recipro-cating internal combustion engines (ICE). The centrifugal compressor in tur-bochargers is limited at off-design operating conditions by the inception of flowinstabilities causing rotating stall and surge. They occur at reduced enginespeeds (low mass flow rates), i.e. typical operating conditions for a betterengine fuel economy, harming ICEs...

  14. Measurement and Calibration of Centrifugal Compressor Pressure Scanning Instrumentation

    OpenAIRE

    Rivas, Jose R; Lou, Fangyuan; Harrison, Herbert "Trey"; Key, Nicole

    2015-01-01

    The compressor is a key component of a jet engine necessary to compress air for the combustion process. Research to optimize compressor efficiency through the understanding of air flow behavior has led to increased efforts in creating modern compressor test facilities. In collaboration with Honeywell, the High Speed Compressor facility at Zucrow Laboratories has built a centrifugal compressor test cell with instrumentation to measure the temperatures and pressures of the air flow. This facili...

  15. Impeller Design of a Centrifugal Fan with Blade Optimization

    OpenAIRE

    Yu-Tai Lee; Vineet Ahuja; Ashvin Hosangadi; Michael E. Slipper; Lawrence P. Mulvihill; Roger Birkbeck; Coleman, Roderick M.

    2011-01-01

    A method is presented for redesigning a centrifugal impeller and its inlet duct. The double-discharge volute casing is a structural constraint and is maintained for its shape. The redesign effort was geared towards meeting the design volute exit pressure while reducing the power required to operate the fan. Given the high performance of the baseline impeller, the redesign adopted a high-fidelity CFD-based computational approach capable of accounting for all aerodynamic losses. The present eff...

  16. Centrifuge modeling of rocking-isolated inelastic RC bridge piers

    OpenAIRE

    Loli, Marianna; Knappett, Jonathan A; Brown, Michael J.; Anastasopoulos, Ioannis; GAZETAS, George

    2014-01-01

    Experimental proof is provided of an unconventional seismic design concept, which is based on deliberately underdesigning shallow foundations to promote intense rocking oscillations and thereby to dramatically improve the seismic resilience of structures. Termed rocking isolation, this new seismic design philosophy is investigated through a series of dynamic centrifuge experiments on properly scaled models of a modern reinforced concrete (RC) bridge pier. The experimental method reproduces th...

  17. Fault Diagnosis in a Centrifugal Pump Using Active Magnetic Bearings

    OpenAIRE

    Nordmann Rainer; Aenis Martin

    2004-01-01

    The number of rotors running in active magnetic bearings (AMBs) has increased over the last few years. These systems offer a great variety of advantages compared to conventional systems. The aim of this article is to use the AMBs together with a developed built-in software for identification, fault detection, and diagnosis in a centrifugal pump. A single-stage pump representing the turbomachines is investigated. During full operation of the pump, the AMBs are used as actuators to generate def...

  18. Comparative hemolysis study of clinically available centrifugal pumps.

    Science.gov (United States)

    Naito, K; Suenaga, E; Cao, Z L; Suda, H; Ueno, T; Natsuaki, M; Itoh, T

    1996-06-01

    Centrifugal pumps have become important devices for cardiopulmonary bypass and circulatory assistance. Five types of centrifugal pumps are clinically available in Japan. To evaluate the blood trauma caused by centrifugal pumps, a comparative hemolysis study was performed under identical conditions. In vitro hemolysis test circuits were constructed to operate the BioMedicus BP-80 (Medtronic, BioMedicus), Sarns Delphin (Sarns/3M Healthcare), Isoflow (St. Jude Medical [SJM]), HPM-15 (Nikkiso), and Capiox CX-SP45 (Terumo). The hemolysis test loop consisted of two 1.5 m lengths of polyvinyl chloride tubing with a 3/8-inch internal diameter, a reservoir with a sampling port, and a pump head. All pumps were set to flow at 6 L/min against the total pressure head of 120 mm Hg. Experiments were conducted simultaneously for 6 h at room temperature (21 degrees C) with fresh bovine blood. Blood samples for plasma-free hemoglobin testing were taken, and the change in temperature at the pump outlet port was measured during the experiment. The mean pump rotational speeds were 1,570, 1,374, 1,438, 1,944, and 1,296 rpm, and the normalized indexes of hemolysis were 0.00070, 0.00745, 0.00096, 0.00066, 0.00090 g/100 L for the BP-80, Sarns, SJM, Nikkiso, and Terumo pumps, respectively. The change in temperature at the pump outlet port was the least for the Nikkiso pump (1.8 degrees C) and the most with the SJM pump (3.8 degrees C). This study showed that there is no relationship between the pump rotational speed (rpm) and the normalized index of hemolysis in 5 types of centrifugal pumps. The pump design and number of impellers could be more notable factors in blood damage.

  19. Effects of Different Blade Angle Distributions on Centrifugal Compressor Performance

    OpenAIRE

    Pekka Röyttä; Aki Grönman; Ahti Jaatinen; Teemu Turunen-Saaresti; Jari Backman

    2009-01-01

    A centrifugal compressor with three different shrouded 2D impellers is studied numerically. All impellers have the same dimensions, and they only differ in channel length and geometry. Noticeable differences in efficiency are observed. Two different turbulence models, Chien's k-ε and k-ω SST, are compared. For this case, k-ω SST was found more realistic. The hypothesis that pressure losses in a curved duct and in an impeller passage behave similarly is suggested and found inadequate.

  20. Numerical simulation of the countercurrent flow in a gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Cloutman, L.D.; Gentry, R.A.

    1983-03-01

    We present a finite difference method for the numerical simulation of the axisymmetric countercurrent flow in a gas centrifuge. A time-marching technique is used to relax an arbitrary initial condition to the desired steady-state solution. All boundary layers can be resolved, and nonlinear effects may be included. Numerical examples are presented. We conclude that this technique is capable of predicting accurately the performance of a wide variety of machines under all operating conditions of interest.

  1. Cyclonic Separation Technology: Researches and Developments

    Institute of Scientific and Technical Information of China (English)

    汪华林; 张艳红; 王剑刚; 刘洪来

    2012-01-01

    Centered on thetechniques and industrial applications of the reinforced cyclonic separation process, its principles and mechanism for separation ot ions, molecules and their aggregates using polyalsperse aroplets are discussed generally; the characteristics and influential factors of fish-hook phenomenon of the grade efficiency curve in cyclonic separation for both gas and liquid are analyzed; and the influence of shear force on particle be- havior (or that of particle swarm) is also summarized. A novel idea for cyclonic separation is presented here: enhancing the cyclonic seoaration process of ions, molecules and their aggregates with monodisperse microspheres and their surface grafting, rearranging the distribution of particles by size using centrifugal field, reinforcing the cyclonic separation performance with orderly arranged particle swarm. Also the investigation of the shortcut flow, recirculation flow, the asymmetric structure and non-linear characteristics of the cyclonic flow field with a com-bined method of Volumetric 3-component Velocimetry (V3V) and Phase-Doppler Particle Anemometer (PDPA) are elaborated. It is recommended to develop new systems for the separation of heterogeneous phases with cyclonic technology, in accordance with the capture and reuse of CO2, methanol to olefins (MTO) process, coal transfer, andthe exploitation of oil shale.

  2. Phase characterization in two centrifugally cast HK stainless steel tubes

    International Nuclear Information System (INIS)

    The petrochemical industry has been using 25% Cr - 20% Ni centrifugally cast stainless steel since the early 1960s in reformer and pyrolysis furnaces. This class of material has replaced the traditional superalloys showing similar creep behavior, with substantial reduction in costs. The use of the centrifugal casting technique for tube production has also contributed to better quality in these components. During the past two decades, several studies have been conducted concerning the improvement in the performance of this material at high temperatures. Some of them were related to failure analysis and life prediction, while others were related to the chemical composition balance and to new alloying procedures. As a consequence, a new generation of centrifugally cast steels has been developed in the form of niobium-modified HK and HP steels. The creep resistance of these alloys appears to be dependent on the composition, morphology, and distribution of carbides that form within them. The purpose of the study reported herein is to characterize the precipitation effects occurring during long- term service in two HK-type steels, one being of basic HK composition and the other a niobium-modified alloy

  3. Governing Principles of Alginate Microparticle Synthesis with Centrifugal Forces.

    Science.gov (United States)

    Eral, Huseyin Burak; Safai, Eric R; Keshavarz, Bavand; Kim, Jae Jung; Lee, Jisoek; Doyle, P S

    2016-07-19

    A controlled synthesis of polymeric particles is becoming increasingly important because of emerging applications ranging from medical diagnostics to self-assembly. Centrifugal synthesis of hydrogel microparticles is a promising method, combining rapid particle synthesis and the ease of manufacturing with readily available laboratory equipment. This method utilizes centrifugal forces to extrude an aqueous polymer solution, sodium alginate (NaALG) through a nozzle. The extruded solution forms droplets that quickly cross-link upon contact with aqueous calcium chloride (CaCl2) solution to form hydrogel particles. The size distribution of hydrogel particles is dictated by the pinch-off behavior of the extruded solution through a balance of inertial, viscous, and surface tension stresses. We identify the parameters dictating the particle size and provide a numerical correlation predicting the average particle size. Furthermore, we create a phase map identifying different pinch-off regimes (dripping without satellites, dripping with satellites, and jetting), explaining the corresponding particle size distributions, and present scaling arguments predicting the transition between regimes. By shedding light on the underlying physics, this study enables the rational design and operation of particle synthesis by centrifugal forces.

  4. Numerical Analysis and Centrifuge Modeling of Shallow Foundations

    Institute of Scientific and Technical Information of China (English)

    罗强; 栾茂田; 杨蕴明; 王忠涛; 赵守正

    2014-01-01

    The influence of non-coaxial constitutive model on predictions of dense sand behavior is investigated in this paper. The non-coaxial model with strain softening plasticity is applied into finite-element program ABAQUS, which is first used to predict the stress-strain behavior and the non-coaxial characteristic between the orientations of the principal stress and principal plastic strain rate in simple shear tests. The model is also used to predict load settlement responses and bearing capacity factors of shallow foundations. A series of centrifuge tests for shallow foundations on saturated dense sand are performed under drained conditions and the test results are compared with the corresponding numerical results. Various footing dimensions, depths of embedment, and footing shapes are considered in these tests. In view of the load settlement relationships, the stiffness of the load-displacement curves is significantly affected by the non-coaxial model compared with those predicted by the coaxial model, and a lower value of non-coaxial modulus gives a softer response. Considering the soil behavior at failure, the coaxial model predictions of bearing capacity factors are more advanced than those of centrifuge test results and the non-coaxial model results;besides, the non-coaxial model gives better predictions. The non-coaxial model predictions are closer to those of the centrifuge results when a proper non-coaxial plastic modulus is chosen.

  5. Flow measurements in a centrifugal diffusor test device

    Science.gov (United States)

    Vitting, T.

    1985-06-01

    This work sought to verify concepts used in the design of a large scale, low speed, radial cascade wind tunnel which was to be used to investigate flow phenomena in and the performance of vaned radial diffusors. A major contributor to centrifugal compressor efficiency is the performance of the vaned diffusor which closely follows the impeller of the compressor. The purpose of this diffusor is to efficiently convert most of the kinetic energy of the transonic flow entering the vane into pressure. The need for an experimental facility which could simulate adequately, at low cost and in a controlled way, the environment of the centrifugal compressor motivated the development of the Centrifugal Diffusor Test Device (CDTD). It was expected that the generation of a three dimensional flow would provide improved empirical data on annular cascade performance. This measurement program surveyed the axial and circumferential uniformity of the flow at the inlet of a transonic wedge-type blading mounted in the device. Evaluation of the results showed the flow uniformity to be unsatisfactory. Leakage and other small perturbations in the flow field in the swirl generator are believed to be amplified by the basic flow configuration of the device.

  6. Modelling of horizontal centrifugal casting of work roll

    Science.gov (United States)

    Xu, Zhian; Song, Nannan; Tol, Rob Val; Luan, Yikun; Li, Dianzhong

    2012-07-01

    A numerical model to simulate horizontal centrifugal roll castings is presented in this paper. In order to simulate the flow fluid and solidification of horizontal centrifugal roll casting correctly, the model uses a body fitted mesh technique to represent the geometry. This new method maps a plate layer mesh to a circular mesh. The smooth body fitted mesh method gives more accurate calculation results for cylindrical geometries. A velocity depending on the angular velocity and inner radius of the mould is set up as a velocity boundary condition. The fluid flow coupled with heat transfer and solidification in a rapidly rotating roll is simulated. A gravity free falling method is applied as a pouring condition. A moveable pouring system is also used in the simulations. High speed steel is used to produce the work roll. Two different gating positions and a moveable gating system are simulated in this paper. Results show that the position of pouring system has a significant influence on the temperature distribution. The temperature distribution at a fixed central pouring system is more favourable than the distribution from a side pouring system. A moving gating system method is a better way to obtain a uniform temperature field in centrifugal casting and offers an alternative for existing techniques.

  7. Governing Principles of Alginate Microparticle Synthesis with Centrifugal Forces.

    Science.gov (United States)

    Eral, Huseyin Burak; Safai, Eric R; Keshavarz, Bavand; Kim, Jae Jung; Lee, Jisoek; Doyle, P S

    2016-07-19

    A controlled synthesis of polymeric particles is becoming increasingly important because of emerging applications ranging from medical diagnostics to self-assembly. Centrifugal synthesis of hydrogel microparticles is a promising method, combining rapid particle synthesis and the ease of manufacturing with readily available laboratory equipment. This method utilizes centrifugal forces to extrude an aqueous polymer solution, sodium alginate (NaALG) through a nozzle. The extruded solution forms droplets that quickly cross-link upon contact with aqueous calcium chloride (CaCl2) solution to form hydrogel particles. The size distribution of hydrogel particles is dictated by the pinch-off behavior of the extruded solution through a balance of inertial, viscous, and surface tension stresses. We identify the parameters dictating the particle size and provide a numerical correlation predicting the average particle size. Furthermore, we create a phase map identifying different pinch-off regimes (dripping without satellites, dripping with satellites, and jetting), explaining the corresponding particle size distributions, and present scaling arguments predicting the transition between regimes. By shedding light on the underlying physics, this study enables the rational design and operation of particle synthesis by centrifugal forces. PMID:27311392

  8. Subchronic centrifugal mechanical assist in an unheparinized calf model.

    Science.gov (United States)

    Wagner-Mann, C; Curtis, J; Mann, F A; Turk, J; Demmy, T; Turpin, T

    1996-06-01

    The purpose of this study was to determine whether the major centrifugal pumps currently in use in the United States (Medtronic, BioMedicus BioPump and Carmeda-coated BioPump, Sarns 3M centrifugal pump, and St. Jude Medical Lifestream) could function as left mechanical assist devices in the subchronic (72 h) unheparinized calf model. Calves were instrumented for left atrial to aorta ex vivo assist, and the pump flow was set at 3.5 +/- 0.4 L/min. Two calves (Sarns 3M and St. Jude) survived 72 h of pumping without clinical complications. The other 2 calves died at 62 and 66 h (Medtronic BioPump and Carmeda-coated BioPump, respectively); both had pelvic limb paralysis. The seal of the Sarns 3M pump head ruptured after approximately 36 h of pumping and required replacement. On postmortem examination, pump-associated thromboembolic lesions were detected in 3 of the 4 calves in one or more of the following organs: kidneys, pancreas, abomasum, duodenum, ileum, spleen, and lumbar spinal cord. The calf with the Sarns 3M pump had no discernable lesions. Because of the clinical abnormalities and postmortem lesions in the unheparinized calf model, it was suggested that anticoagulation is necessary for conducting centrifugal mechanical assist studies in calves using presently available technology.

  9. Extraction of cocoa proanthocyanidins and their fractionation by sequential centrifugal partition chromatography and gel permeation chromatography.

    Science.gov (United States)

    Pedan, Vasilisa; Fischer, Norbert; Rohn, Sascha

    2016-08-01

    Cocoa beans contain secondary metabolites ranging from simple alkaloids to complex polyphenols with most of them believed to possess significant health benefits. The increasing interest in these health effects has prompted the need to develop techniques for their extraction, fractionation, separation, and analysis. This work provides an update on analytical procedures with a focus on establishing a gentle extraction technique. Cocoa beans were finely ground to an average particle size of <100 μm, defatted at 20 °C using n-hexane, and extracted three times with 50 % aqueous acetone at 50 °C. Determination of the total phenolic content was done using the Folin-Ciocalteu assay, the concentration of individual polyphenols was analyzed by electrospray ionization high performance liquid chromatography-mass spectrometry (ESI-HPLC/MS). Fractions of bioactive compounds were separated by combining sequential centrifugal partition chromatography (SCPC) and gel permeation column chromatography using Sephadex LH-20. For SCPC, a two-phase solvent system consisting of ethyl acetate/n-butanol/water (4:1:5, v/v/v) was successfully applied for the separation of theobromine, caffeine, and representatives of the two main phenolic compound classes flavan-3-ols and flavonols. Gel permeation chromatography on Sephadex LH-20 using a stepwise elution sequence with aqueous acetone has been shown for effectively separating individual flavan-3-ols. Separation was obtained for (-)-epicatechin, proanthocyanidin dimer B2, trimer C1, and tetramer cinnamtannin A2. The purity of alkaloids and phenolic compounds was determined by HPLC analysis and their chemical identity was confirmed by mass spectrometry. PMID:27318471

  10. A high-efficiency superhydrophobic plasma separator.

    Science.gov (United States)

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M; Yang, Shu; Bau, Haim H

    2016-02-01

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method.

  11. A high-efficiency superhydrophobic plasma separator.

    Science.gov (United States)

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M; Yang, Shu; Bau, Haim H

    2016-02-01

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method. PMID:26732765

  12. Laser Anemometer Measurements of the Flow Field in a 4:1 Pressure Ratio Centrifugal Impeller

    Science.gov (United States)

    Skoch, G. J.; Prahst, P. S.; Wernet, M. P.; Wood, J. R.; Strazisar, A. J.

    1997-01-01

    A laser-doppler anemometer was used to obtain flow-field velocity measurements in a 4:1 pressure ratio, 4.54 kg/s (10 lbm/s), centrifugal impeller, with splitter blades and backsweep, which was configured with a vaneless diffuser. Measured through-flow velocities are reported for ten quasi-orthogonal survey planes at locations ranging from 1% to 99% of main blade chord. Measured through-flow velocities are compared to those predicted by a 3-D viscous steady flow analysis (Dawes) code. The measurements show the development and progression through the impeller and vaneless diffuser of a through-flow velocity deficit which results from the tip clearance flow and accumulation of low momentum fluid centrifuged from the blade and hub surfaces. Flow traces from the CFD analysis show the origin of this deficit which begins to grow in the inlet region of the impeller where it is first detected near the suction surface side of the passage. It then moves toward the pressure side of the channel, due to the movement of tip clearance flow across the impeller passage, where it is cut by the splitter blade leading edge. As blade loading increases toward the rear of the channel the deficit region is driven back toward the suction surface by the cross-passage pressure gradient. There is no evidence of a large wake region that might result from flow separation and the impeller efficiency is relatively high. The flow field in this impeller is quite similar to that documented previously by NASA Lewis in a large low-speed backswept impeller.

  13. Task 9 - centrifugal membrane filtration. Semi-annual report April 1--September 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Stepan, D.J.; Moe, T.A.; Collings, M.E.

    1997-05-01

    This report assesses a centrifugal membrane filtration technology developed by SpinTek Membrane Systems, Inc. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. The Tank Waste Focus Area was chosen for study. Membrane-screening tests were performed with the STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-{mu}m TiO{sub 2}/Al{sub 2}O{sub 3} membrane was selected for detailed performance evaluation using the centrifugal membrane filtration unit with a surrogate tank waste solution. The performance of the unit was evaluated with a statistical test design that determined the effect of temperature, pressure, membrane rotational speed, and solids loading on permeate flux. All four variables were found to be statistically significant, with the magnitude of the effect in the order of temperature, solids loading, rotor speed, and pressure. Temperature, rotor speed, and pressure had an increasing effect on flux with increasing value, while increases in solids loading showed a decrease in permeate flux. Significant interactions between rotor speed and solids loading and pressure and solids loading were also observed. The regression equation derived from test data had a correlation coefficient of 0.934, which represents a useful predictive capability for integrating the technology into DOE cleanup efforts. An extended test run performed on surrogate waste showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance.

  14. Task 9 - centrifugal membrane filtration. Semi-annual report April 1--September 30, 1996

    International Nuclear Information System (INIS)

    This report assesses a centrifugal membrane filtration technology developed by SpinTek Membrane Systems, Inc. The technology uses supported microporous membranes rotating at high rpm, under pressure, to separate suspended and colloidal solids from liquid streams, yielding a solids-free permeate stream and a highly concentrated solids stream. The Tank Waste Focus Area was chosen for study. Membrane-screening tests were performed with the STC-X4 static test cell filtration unit, using five ceramic membranes with different pore size and composition. Based on permeate flux, a 0.25-μm TiO2/Al2O3 membrane was selected for detailed performance evaluation using the centrifugal membrane filtration unit with a surrogate tank waste solution. The performance of the unit was evaluated with a statistical test design that determined the effect of temperature, pressure, membrane rotational speed, and solids loading on permeate flux. All four variables were found to be statistically significant, with the magnitude of the effect in the order of temperature, solids loading, rotor speed, and pressure. Temperature, rotor speed, and pressure had an increasing effect on flux with increasing value, while increases in solids loading showed a decrease in permeate flux. Significant interactions between rotor speed and solids loading and pressure and solids loading were also observed. The regression equation derived from test data had a correlation coefficient of 0.934, which represents a useful predictive capability for integrating the technology into DOE cleanup efforts. An extended test run performed on surrogate waste showed some deterioration in filtration performance, based on flux, apparently due to the buildup of solids near the inner portion of the membrane where relative membrane velocities were low. Continued testing of the system will focus on modifications to the shear pattern across the entire membrane surface to affect improved long-term performance

  15. A comprehensive classification of solvent systems used for natural product purifications in countercurrent and centrifugal partition chromatography.

    Science.gov (United States)

    Skalicka-Woźniak, Krystyna; Garrard, Ian

    2015-11-01

    Using both library paper copies and modern electronic copies, every known, published, English-language journal paper that employs either countercurrent or centrifugal partition chromatography solvent systems for natural product purifications has been studied and the solvent systems classified in a comprehensive database. Papers were studied from the earliest found examples containing natural product separations in 1984 until the end of 2014. In total, 2594 solvent systems have been classified, of which 272 are gradient systems. To observe any trends or patterns in the data, the natural product solutes were divided into 21 classes and the solvent systems into 7 different types. The complete database, sorted according to natural product class, is available for download to assist separation scientists in future liquid-liquid chromatography purifications. PMID:26219437

  16. Influence of blade angle distribution along leading edge on cavitation performance of a centrifugal pump

    Science.gov (United States)

    Xu, Y.; Tan, L.; Cao, S. L.; Wang, Y. C.; Meng, G.; Qu, W. S.

    2015-01-01

    The influence of blade angle distribution along leading edge on cavitation performance of centrifugal pumps is analysed in the present paper. Three sets of blade angle distribution along leading edge for three blade inlet angles are chosen to design nine centrifugal pump impellers. The RNG k-epsilon turbulence model and the Zwart-Gerber-Belamri cavitation model are employed to simulate the cavitation flows in centrifugal pumps with different impellers and the same volute. The numerical results are compared with the experimental data, and the comparison proves that the numerical simulation can accurately predict the cavitation performance of centrifugal pumps. On the basis of the numerical simulations, the pump head variations with pump inlet pressure, and the flow details in centrifugal pump are revealed to demonstrate the influence of blade angle distribution along leading edge on cavitation performances of centrifugal pumps.

  17. Enriched surface acidity for surfactant-free suspensions of carboxylated carbon nanotubes purified by centrifugation

    Directory of Open Access Journals (Sweden)

    Elizabeth I. Braun

    2016-06-01

    Full Text Available It is well known that surfactant-suspended carbon nanotube (CNT samples can be purified by centrifugation to decrease agglomerates and increase individually-dispersed CNTs. However, centrifugation is not always part of protocols to prepare CNT samples used in biomedical applications. Herein, using carboxylated multi-walled CNTs (cMWCNTs suspended in water without a surfactant, we developed a Boehm titrimetric method for the analysis of centrifuged cMWCNT suspensions and used it to show that the surface acidity of oxidized carbon materials in aqueous cMWCNT suspensions was enriched by ∼40% by a single low-speed centrifugation step. This significant difference in surface acidity between un-centrifuged and centrifuged cMWCNT suspensions has not been previously appreciated and is important because the degree of surface acidity is known to affect the interactions of cMWCNTs with biological systems.

  18. Fast Centrifugal Partition Chromatography Fractionation of Concentrated Agave (Agave salmiana) Sap to Obtain Saponins with Apoptotic Effect on Colon Cancer Cells.

    Science.gov (United States)

    Santos-Zea, Liliana; Fajardo-Ramírez, Oscar R; Romo-López, Irasema; Gutiérrez-Uribe, Janet A

    2016-03-01

    Separation of potentially bioactive components from foods and plant extracts is one of the main challenges for their study. Centrifugal partition chromatography has been a successful technique for the screening and identification of molecules with bioactive potential, such as steroidal saponins. Agave is a source of steroidal saponins with anticancer potential, though the activity of these compounds in concentrated agave sap has not been yet explored. In this study, fast centrifugal partition chromatography (FCPC) was used coupled with in vitro tests on HT-29 cells as a screening procedure to identify apoptotic saponins from an acetonic extract of concentrated agave sap. The three most bioactive fractions obtained by FCPC at partition coefficients between 0.23 and 0.4 contained steroidal saponins, predominantly magueyoside b. Flow cytometry analysis determined that the fraction rich in kammogenin and manogenin glycosides induced apoptosis, but when gentrogenin and hecogenin glycosides were also found in the fraction, a necrotic effect was observed. In conclusion, this study provides the evidence that steroidal saponins in concentrated agave sap were potential inductors of apoptosis and that it was possible to separate them using fast centrifugal partition chromatography.

  19. Fast Centrifugal Partition Chromatography Fractionation of Concentrated Agave (Agave salmiana) Sap to Obtain Saponins with Apoptotic Effect on Colon Cancer Cells.

    Science.gov (United States)

    Santos-Zea, Liliana; Fajardo-Ramírez, Oscar R; Romo-López, Irasema; Gutiérrez-Uribe, Janet A

    2016-03-01

    Separation of potentially bioactive components from foods and plant extracts is one of the main challenges for their study. Centrifugal partition chromatography has been a successful technique for the screening and identification of molecules with bioactive potential, such as steroidal saponins. Agave is a source of steroidal saponins with anticancer potential, though the activity of these compounds in concentrated agave sap has not been yet explored. In this study, fast centrifugal partition chromatography (FCPC) was used coupled with in vitro tests on HT-29 cells as a screening procedure to identify apoptotic saponins from an acetonic extract of concentrated agave sap. The three most bioactive fractions obtained by FCPC at partition coefficients between 0.23 and 0.4 contained steroidal saponins, predominantly magueyoside b. Flow cytometry analysis determined that the fraction rich in kammogenin and manogenin glycosides induced apoptosis, but when gentrogenin and hecogenin glycosides were also found in the fraction, a necrotic effect was observed. In conclusion, this study provides the evidence that steroidal saponins in concentrated agave sap were potential inductors of apoptosis and that it was possible to separate them using fast centrifugal partition chromatography. PMID:26701355

  20. Differentiating Central Centrifugal Cicatricial Alopecia and Androgenetic Alopecia in African American Men: Report of Three Cases

    OpenAIRE

    Davis, Erica C.; Reid, Sophia D.; Callender, Valerie D.; Sperling, Leonard C.

    2012-01-01

    Central centrifugal cicatricial alopecia is a scarring alopecia that is predominantly seen in African American women, but occurs less frequently in men. The authors present three cases of African American men with biopsy-proven central centrifugal cicatricial alopecia and detail the clinical presentation, histological findings, and treatment regimens. Central centrifugal cicatricial alopecia should be considered in the differential diagnosis when evaluating male patients with vertex hair loss...

  1. Computer precision simulation for titanium casting centrifugal mold filling of prescision titanium castings

    OpenAIRE

    Xu, Daming; LI, XIN; Geving AN

    2004-01-01

    Computer simulation codes were developed based on proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings. Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings unde a centrifugal force fi...

  2. The Dynamics of Stall and Surge Behavior in Axial-Centrifugal Compressors

    OpenAIRE

    Cousins, William T.

    1997-01-01

    The phenomena of stall and surge in axial-centrifugal compressors is investigated through high-response measurements of both the pressure field and the flowfield throughout the surge cycle. A unique high-response forward-facing and aft-facing probe provides flow information. Several axial-centrifugal compressors are examined, both in compressor rigs and engines. Extensive discussion is presented on the differences in axial and centrifugal rotors and their effect on the system response char...

  3. Increasing the Stable Operating Range of a Fixed-Geometry Variable-Speed Centrifugal Compressor

    OpenAIRE

    Brasz, Joost J.

    2014-01-01

    Centrifugal compressors used on water-cooled chillers require stable operation over a wide range of flows at greatly varying pressure ratios. These operational requirements are dictated by variations in cooling demand and ambient conditions. Variable-speed centrifugal compressors are known to maintain their peak efficiency at the varying operating conditions much better than fixed-speed compressors. Replacing a fixed-speed centrifugal compressor with a variable speed one can reduce the annual...

  4. A New Optimization Method for Centrifugal Compressors Based on 1D Calculations and Analyses

    OpenAIRE

    Pei-Yuan Li; Chu-Wei Gu; Yin Song

    2015-01-01

    This paper presents an optimization design method for centrifugal compressors based on one-dimensional calculations and analyses. It consists of two parts: (1) centrifugal compressor geometry optimization based on one-dimensional calculations and (2) matching optimization of the vaned diffuser with an impeller based on the required throat area. A low pressure stage centrifugal compressor in a MW level gas turbine is optimized by this method. One-dimensional calculation results show that D3/D...

  5. Quantification of platelets obtained by different centrifugation protocols in SHR rats

    Directory of Open Access Journals (Sweden)

    João Alberto Yazigi Junior

    2015-12-01

    Full Text Available ABSTRACT OBJECTIVE: To quantify the platelet concentration in the blood of SHR rats, by means of different centrifugation protocols, and to evaluate what the most effective method for obtaining platelets is. METHODS: We used 40 male rats of the isogenic SHR lineage. The animals were divided into three groups: control, using whole blood without centrifugation; single centrifugation, using whole blood subjected to a single centrifugation at 200 × gand 400 × g; and double centrifugation, using whole blood subjected one centrifugation at different rotations, followed by collection of whole plasma subjected to another centrifugation at different rotations: 200 × g+ 200 ×g; 200 × g+ 400 × g; 200 × g+ 800 × g; 400 ×g+ 400 × g; 400 × g+ 800 × g. Samples of 3 ml of blood were drawn from each animal by means of cardiac puncture. The blood was stored in Vacutainer collection tubes containing 3.2% sodium citrate. The blood from the control group animals was analyzed without being subjected to centrifugation. After the blood from the other groups of animals had been subjected to centrifugation, the whole plasma was collected and subjected to platelet counting in the lower third of the sample. RESULTS: We obtained greatest platelet enrichment in the subgroup with two centrifugations comprising 400 × gfor 10 min + 400 ×gfor 10 min, in which the mean platelet concentration was 11.30 times higher than that of the control group. CONCLUSION: It was possible to obtain a high platelet concentration using viable simple techniques, by means of centrifugation of whole blood and use of commonly used materials. The most effective method for obtaining platelet concentrate was found in samples subjected to two centrifugations.

  6. A REVIEW PAPER ON DEVELOPMENT OF IMPELLER OF CENTRIFUGAL PUMP USING COMPUTATIONAL FLUID DYNAMICS

    OpenAIRE

    Mr. Nilesh Nemgonda Patil

    2015-01-01

    Nowadays, the centrifugal pumps became very popular because of recent development of high speed electric motors, steam turbines etc.Centrifugal pumps can be single-stage or may be multistage pumps. It depends upon the number of impellers used in the pump. Single stage pump consists of only one impeller while in multistage pumps the impellers are mounted in the series in pumps. These Centrifugal pumps can be analyzed by software code like Computational Fluid Dynamics (CFD).This CFD...

  7. WATER RETENTION VALUE MEASUREMENTS OF CELLULOSIC MATERIALS USING A CENTRIFUGE TECHNIQUE

    OpenAIRE

    Jinxin Wang; Qingzheng Cheng; Joseph McNeel; Peter Jacobson

    2010-01-01

    A centrifugal method has been modified and applied to the assessment of water retention value (WRV) in cellulosic materials. Microcrystalline cellulose (MCC), small particles/fibrils isolated from MCC using high-pressure homogenizer, and pulp fibers saturated in water were centrifuged at different speeds and times with filter paper and/or a membrane acting as the filter in the WRV measurement setup. As centrifugal speed, time, and filter pore-size increased, lower WRVs were obtained. Smaller ...

  8. Medical incidences during centrifuge training and F-16 flying in the Netherlands

    OpenAIRE

    Holewijn, M.

    1996-01-01

    A survey in the NAMC database containing the records of centrifuge runs of candidate and experienced pilots revealed that in 15.1% of the centrifuge training sessions, a run was stopped. The major reasons were motion sickness (31%), fatigue (28%), and arrhythmias (22%). During centrifuge training at the NAMC the prevalence of an episode of supra ventricular ectopies was 33%. In 21% of the runs a ventricular ectopie occurred. In-flight ECG monitoring revealed that arrhythmias occurred in 62% o...

  9. Adiabatic field-free alignment of asymmetric top molecules with an optical centrifuge

    CERN Document Server

    Korobenko, A

    2015-01-01

    We use an optical centrifuge to align asymmetric top $\\mathrm{SO_2}$ molecules by adiabatically spinning their most polarizable O-O axis. The effective centrifugal potential in the rotating frame confines sulfur atoms to the plane of the laser-induced rotation, leading to the planar molecular alignment which persists after the molecules are released from the centrifuge. Periodic appearance of the full three-dimensional alignment, typically observed only with linear and symmetric top molecules, is also detected. Together with strong in-plane centrifugal forces, which bend the molecules by up to 10 degrees, permanent field-free alignment offers new ways of controlling molecules with laser light.

  10. High Order Centrifugal Distortion Corrections to Energy Levels of Asymmetric Top Molecules

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-Yan; LIU Xiao-Yong; LIU Hong-Ping; GUO Yuan-Qing; HUANG Guang-Ming; LIN Jie-Li; GAO Hui

    2000-01-01

    High order centrifugal distortion terms have been derived and added to the effective Hamiltonian of asymmetric top molecules. Based on this Hamiltonian, a program in Fortran 77 has been developed for spectral analysis of asymmetric top molecules. The high order centrifugal distortion terms are found to be non-negligible even for the low-lying rotational transitions of molecules, such as Ha 18O, subjected to severe centrifugal distortion effect,and for the high-lying rotational transitions of molecules, such as 14N16O2 subjected to the moderate centrifugal distortion effect.

  11. Computer precision simulation for titanium casting centrifugal mold filling of prescision titanium castings

    Directory of Open Access Journals (Sweden)

    Daming XU

    2004-08-01

    Full Text Available Computer simulation codes were developed based on proposed mathematical model for centrifugal mold filling processes and previous computer software for 3D mold filling and solidification of castings. Sample simulations were implemented for mold filling processes of precision titanium castings under gravity and different centrifugal casting techniques. The computation results show that the alloy melt has a much stronger mold filling ability for thin section castings unde a centrifugal force field than that only under the gravity. A "return back" mold filling manner is showed to be a reasonable technique for centrifugal casting processes, especially for thin section prcision castings.

  12. Study of the potential for improving the economics of hydrogen liquefaction through the use of centrifugal compressors and the addition of a heavy water plant

    Science.gov (United States)

    Baker, C. R.

    1977-01-01

    An approach to the liquefaction of hydrogen was developed which permits the application of standard centrifugal compressors in place of reciprocating machines. A second fluid, such as propane, is added to the hydrogen prior to compression to form a mixture having a molecular weight much greater than that of hydrogen alone, so that a standard centrifugal compressor can be used. After compression, the mixture is cooled to cryogenic temperature levels where the propane condenses out of the mixture and is separated as a liquid. Since a small amount of deuterium is produced during hydrogen liquefaction, the potential of recovering deuterium and selling it as a co-product was investigated. Deuterium, in the form of heavy water, can be used in certain nuclear reactors as a neutron moderator to reduce the neutron velocity and enhance the probability of neutron collision with uranium nucleii.

  13. Performance Test of a R134a Centrifugal Water Chiller

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeonkoo; Yoon, Pil Hyun; Kim, Choon Dong; Lee, Yong Duck; Jeong, Jinhee [LG Cable Ltd., Anyang (Korea)

    2001-05-01

    A centrifugal water chiller using alternative refrigerant R134a have been developed. The prototype was designed to have refrigeration capacity of 300 RT. Its compressor employs a single high-speed impeller, airfoil diffuser and collector. Newly developed enhanced tubes were installed in the evaporator and the condenser to reduce the required head for the compressor. Off-design characteristics at various conditions, performance test of the compressor and analysis of the refrigeration cycle were performed. So the probability of use in part load condition was checked and the direction for revision was suggested. 5 refs., 11 figs., 2 tabs.

  14. Effect of centrifugal pump impeller shapes on cavitation erosion

    International Nuclear Information System (INIS)

    The cavitation erosion test and suction performance test for five types of centrifugal pump impellers with different blade inlet angles and different position of blade inlet edges are carried out by using the open-type pump test loop and painting method. The relationship among the shape of impellers, flow rate, pump running time and position, degree of cavitation erosion inside impellers are made clear under the state of 3% pump head dropping. The experimental results are discussed with the internal flow pattern and inlet reverse flow occurred in the pump

  15. Capture into resonance and phase space dynamics in optical centrifuge

    CERN Document Server

    Armon, Tsafrir

    2016-01-01

    The process of capture of a molecular enesemble into rotational resonance in the optical centrifuge is investigated. The adiabaticity and phase space incompressibility are used to find the resonant capture probability in terms of two dimensionless parameters P1,P2 characterising the driving strength and the nonlinearity, and related to three characteristic time scales in the problem. The analysis is based on the transformation to action-angle variables and the single resonance approximation, yielding reduction of the three-dimensional rotation problem to one degree of freedom. The analytic results for capture probability are in a good agreement with simulations. The existing experiments satisfy the validity conditions of the theory.

  16. Methods of observation of the centrifugal quantum states of neutrons

    Science.gov (United States)

    Cubitt, R.; Nesvizhevsky, V. V.; Petukhov, A. K.; Voronin, A. Yu.; Pignol, G.; Protasov, K. V.; Gurshijants, P.

    2009-12-01

    We propose methods for observation of the quasi-stationary states of neutrons, localized near a curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror's optical potential. This phenomenon is an example of an exactly solvable "quantum bouncer" problem that can be studied experimentally. It could provide a new tool for studying fundamental neutron-matter interactions, neutron quantum optics and surface physics effects. The feasibility of observation of such quantum states has been proven in first experiments.

  17. Methods of observation of the centrifugal quantum states of neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cubitt, R. [Institut Laue-Langevin (ILL), 6 rue Jules Horowitz, F-38042 Grenoble (France); Nesvizhevsky, V.V., E-mail: nesvizhevsky@ill.e [Institut Laue-Langevin (ILL), 6 rue Jules Horowitz, F-38042 Grenoble (France); Petukhov, A.K. [Institut Laue-Langevin (ILL), 6 rue Jules Horowitz, F-38042 Grenoble (France); Voronin, A.Yu., E-mail: dr.a.voronin@gmail.co [P.N. Lebedev Physical Institute, 53 Leninsky Prospekt, 119991 Moscow (Russian Federation); Pignol, G.; Protasov, K.V. [Laboratoire de Physique Subatomique et de Cosmologie (LPSC), IN2P3-CNRS, UJF, 53, Avenue des Martyrs, F-38026 Grenoble (France); Gurshijants, P. [Institute of Solid State Physics (ISSP), Institutskaya Street 2, 142432 Chernogolovka, Moscow Region (Russian Federation)

    2009-12-11

    We propose methods for observation of the quasi-stationary states of neutrons, localized near a curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror's optical potential. This phenomenon is an example of an exactly solvable 'quantum bouncer' problem that can be studied experimentally. It could provide a new tool for studying fundamental neutron-matter interactions, neutron quantum optics and surface physics effects. The feasibility of observation of such quantum states has been proven in first experiments.

  18. Performance Improvement of a Centrifugal Compressor by Passive Means

    OpenAIRE

    N. Sitaram; Swamy, S. M.

    2012-01-01

    The present experimental investigation deals with performance improvement of a low-speed centrifugal compressor by inexpensive passive means such as turbulence generator placed at different positions and partial shroud near the rotor blade tip. The experiments are carried out at three values of tip clearance, namely 2.2%, 5.1%, and 7.9% of rotor blade height at the exit. Performance tests are carried out for a total of 13 configurations. From these measurements, partial shroud is found to giv...

  19. OFF-DESIGN OPERATION OF IMPELLER OF THE CENTRIFUGAL COMPRESSOR

    Directory of Open Access Journals (Sweden)

    Saim KOÇAK

    2004-02-01

    Full Text Available Inducer and discharge dimensions of impellers of centrifugal compressor are determined as a preliminary design. Blockage factor and inducer dimensionless mass flow are exercised in relation with the relative Mach number. The equation which will be based o off-design calculation, related with the discharge relative Mach number are iterated until it will equal to inducer dimensionless mass flow rate. Then discharge relative Mach number for off-design works is obtained. The results calculated in accordance with pressure, temperature and density are seen to be similar with the theoretical parameters.

  20. Physical modelling of earthquakes in the LCPC centrifuge

    OpenAIRE

    CHAZELAS, JL; Derkx, F.; THOREL, L; Escoffier, S.; Rault, G; BUTTIGIEG, S; COTTINEAU, LM; J. Garnier

    2006-01-01

    This paper presents a set of three new equipments that will enable next the Laboratoire Central des Ponts et Chaussées (LCPC - Nantes - France) to carry out reduced scale physical modeling in the centrifuge for earthquake engineering researches and testing. An earthquake simulator (EQS), designed by ACTIDYN Systems, will enable to apply as well sinus inputs in a wide band of frequencies as real or synthesis earthquakes at the bottom of soil models. This EQS is mono axial and its originality s...

  1. Materialoptimering för diskar i en centrifug

    OpenAIRE

    Johansson, Emma; Klingmark, Erika; Larsson, Johan

    2015-01-01

    Under detta kandidatexamensarbete i lättkonstruktioner har en studie i huruvida det är möjligt att reducera vikten hos en centrifug genomförts. Centriair AB var projektets uppdragsgivare och Jack Delin var industrihandledare under hela processen. Centrifugen som viktreducerades används inom friteringsbranschen och innehåller 200-250 tunna diskar som roterar 3000 varv per minut. Diskarnas uppgift är att separera oljepartiklar från vattendroppar genom att slunga dessa mot de inre väggarna i cen...

  2. Concentration and purification of poliovirus by ultrafiltration and isopycnic centrifugation.

    Science.gov (United States)

    Guskey, L E; Wolff, D A

    1972-07-01

    A method is described by which poliovirus can be rapidly and simply concentrated by the use of a Diaflo XM-50 ultrafilter membrane. Freon-extracted ultrafilter concentrates banded in CsCl provided a 1,724-fold volumetric concentration of poliovirus. During concentration, trypsin-digested cellular material can pass through the ultrafilter membrane, thus providing a versatile means of degrading and eliminating extraneous contaminating proteins. The ultrafilter concentration system is compared with the CsCl cushion system of poliovirus concentration, and both systems are further compared by banding virus and virus capsid material in CsCl by use of isopycnic centrifugation. PMID:4341520

  3. Confusion around the tidal force and the centrifugal force

    OpenAIRE

    Matsuda, Takuya; Isaka, Hiromu; Boffin, Henri M. J.

    2015-01-01

    We discuss the tidal force, whose notion is sometimes misunderstood in the public domain literature. We discuss the tidal force exerted by a secondary point mass on an extended primary body such as the Earth. The tidal force arises because the gravitational force exerted on the extended body by the secondary mass is not uniform across the primary. In the derivation of the tidal force, the non-uniformity of the gravity is essential, and inertial forces such as the centrifugal force are not nee...

  4. Analyses of hydrodynamic radial forces on centrifugal pump impellers

    Science.gov (United States)

    Adkins, D. R.; Brennen, C. E.

    1988-01-01

    An experimental and theoretical study of the hydrodynamic interactions occurring between a centrifugal pump impeller and a volute is presented. The theoretical analysis provides a quasi-one-dimensional treatment of the flow in the volute, and it is extended to include the hydrodynamic force perturbations caused by the impeller whirling eccentrically in the volute. It is noted that these perturbations are often destabilizing. The theoretical models were found to accurately predict the radial forces caused by the flow through the impeller. The pressure acting on the front shroud of the impeller is shown to have a significant effect on the destabilizing hydrodyamic forces.

  5. Gender Differences in Cardiovascular Tolerance to Short Arm Centrifugation

    Science.gov (United States)

    Fong, Kevin J.; Arya, Maneesh; Paloski, William H.

    2007-01-01

    In preparation for the NASA Artificial Gravity (AG) pilot study, the tolerability of the proposed AG parameters was tested in 11 ambulatory human subjects (6m, 5w) by exposing each to a short arm centrifuge trial. Subjects were oriented in the supine position (but inclined 6deg head down) on one arm of the centrifuge, and the rotation rate (30.6-33.4 rpm) and radial position of the feet were set to produce 2.5G of equivalent gravitational load at the force plate directly beneath the feet, 1G at the level of the mediastinum, and approximately 0.55G at the labyrinth. Amongst the 6 men participating in this preliminary study, 5 completed at least 60 minutes of the trial successfully with no adverse sequelae. However, amongst the female cohort the test was stopped by the medical monitor before 60 min in all but one case, with pre-syncope listed as the reason for termination in all cases. Mean time before abort of the centrifuge run amongst the women was 33.2 +/- 20.97 min. It is known that women have a greater predisposition to syncope during orthostatic stress, under normal tilt table conditions, during LBNP, and following space flight. The reasons for this difference are the subject of some debate, but anthropometric factors, the vasoactive effects of sex hormones, gender differences in susceptibility to motion sickness, catecholamine levels, ability to augment total peripheral resistance in response to orthostatic stress, and structural differences in cardiac anatomy and physiology have all been suggested. This finding led to the exclusion of women from the AG pilot study. Clearly if AG is to be employed as a multi-system countermeasure it must provide physiological protection at rotation rates within the tolerance limits of all potential astronauts. Further investigation of the responses of women to centrifugation will be necessary to determine how to adjust AG parameters for tolerance by female subjects before a more detailed investigation of the appropriate dose

  6. Centrifuge modelling of drained lateral pile - soil response

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte

    The installation and foundation cost of offshore wind turbines is substantial, and today energy from offshore wind is not competitive with energy from more classical energy production methods. The goal of this research project has been to develop simple engineering tools, which can be used...... of rigid piles. The tests have been performed in homogeneously dense dry or saturated Fontainebleau sand in order to mimic simplified drained offshore soil conditions. Approximately half of the tests have been carried out to investigate the centrifuge procedure in order to create a methodology of testing...

  7. RING-SHAPED MAGNETIC POTENTIAL BARRIERS FOR SEPARATION OF WEAKLY MAGNETIC PARTICLES

    OpenAIRE

    Gerhold, J.; Schmidt, Julien

    1984-01-01

    Weakly magnetic materials may be separated within Open Gradient Magnetic Separators using dry or wet processes. Axial-symmetric arrangments are of special interest when utilizing centrifugal forces in addition to magnetic forces. Thereby gradient fields are needed which generate mainly radially inwards directed forces. Such forces form a kind of magnetic potential barrier which cannot be transversed by magnetic particles. The necessary field distributions can be attained by means of properly ...

  8. Centrifugo-pneumatic multi-liquid aliquoting - parallel aliquoting and combination of multiple liquids in centrifugal microfluidics.

    Science.gov (United States)

    Schwemmer, F; Hutzenlaub, T; Buselmeier, D; Paust, N; von Stetten, F; Mark, D; Zengerle, R; Kosse, D

    2015-08-01

    The generation of mixtures with precisely metered volumes is essential for reproducible automation of laboratory workflows. Splitting a given liquid into well-defined metered sub-volumes, the so-called aliquoting, has been frequently demonstrated on centrifugal microfluidics. However, so far no solution exists for assays that require simultaneous aliquoting of multiple, different liquids and the subsequent pairwise combination of aliquots with full fluidic separation before combination. Here, we introduce the centrifugo-pneumatic multi-liquid aliquoting designed for parallel aliquoting and pairwise combination of multiple liquids. All pumping and aliquoting steps are based on a combination of centrifugal forces and pneumatic forces. The pneumatic forces are thereby provided intrinsically by centrifugal transport of the assay liquids into dead end chambers to compress the enclosed air. As an example, we demonstrate simultaneous aliquoting of 1.) a common assay reagent into twenty 5 μl aliquots and 2.) five different sample liquids, each into four aliquots of 5 μl. Subsequently, the reagent and sample aliquots are simultaneously transported and combined into twenty collection chambers. All coefficients of variation for metered volumes were between 0.4%-1.0% for intra-run variations and 0.5%-1.2% for inter-run variations. The aliquoting structure is compatible to common assay reagents with a wide range of liquid and material properties, demonstrated here for contact angles between 20° and 60°, densities between 789 and 1855 kg m(-3) and viscosities between 0.89 and 4.1 mPa s. The centrifugo-pneumatic multi-liquid aliquoting is implemented as a passive fluidic structure into a single fluidic layer. Fabrication is compatible to scalable fabrication technologies such as injection molding or thermoforming and does not require any additional fabrication steps such as hydrophilic or hydrophobic coatings or integration of active valves. PMID:26138211

  9. Centrifugo-pneumatic multi-liquid aliquoting - parallel aliquoting and combination of multiple liquids in centrifugal microfluidics.

    Science.gov (United States)

    Schwemmer, F; Hutzenlaub, T; Buselmeier, D; Paust, N; von Stetten, F; Mark, D; Zengerle, R; Kosse, D

    2015-08-01

    The generation of mixtures with precisely metered volumes is essential for reproducible automation of laboratory workflows. Splitting a given liquid into well-defined metered sub-volumes, the so-called aliquoting, has been frequently demonstrated on centrifugal microfluidics. However, so far no solution exists for assays that require simultaneous aliquoting of multiple, different liquids and the subsequent pairwise combination of aliquots with full fluidic separation before combination. Here, we introduce the centrifugo-pneumatic multi-liquid aliquoting designed for parallel aliquoting and pairwise combination of multiple liquids. All pumping and aliquoting steps are based on a combination of centrifugal forces and pneumatic forces. The pneumatic forces are thereby provided intrinsically by centrifugal transport of the assay liquids into dead end chambers to compress the enclosed air. As an example, we demonstrate simultaneous aliquoting of 1.) a common assay reagent into twenty 5 μl aliquots and 2.) five different sample liquids, each into four aliquots of 5 μl. Subsequently, the reagent and sample aliquots are simultaneously transported and combined into twenty collection chambers. All coefficients of variation for metered volumes were between 0.4%-1.0% for intra-run variations and 0.5%-1.2% for inter-run variations. The aliquoting structure is compatible to common assay reagents with a wide range of liquid and material properties, demonstrated here for contact angles between 20° and 60°, densities between 789 and 1855 kg m(-3) and viscosities between 0.89 and 4.1 mPa s. The centrifugo-pneumatic multi-liquid aliquoting is implemented as a passive fluidic structure into a single fluidic layer. Fabrication is compatible to scalable fabrication technologies such as injection molding or thermoforming and does not require any additional fabrication steps such as hydrophilic or hydrophobic coatings or integration of active valves.

  10. Design and test of a high pressure centrifugal compressor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jae Ho; Han, Chak Heui; Paeng, Ki Seok; Chen, Seung Bae [Samsung Techwin, Changwon (Korea, Republic of); Kim, Yong Ryun [Agency for Defense Development, Daejeon (Korea, Republic of)

    2005-07-01

    This paper presents an aerodynamic design, flow analysis and performance test of a pressure ratio 4:1 centrifugal compressor for gas turbine engine. The compressor is made up of a centrifugal impeller, a two-stage diffuser consisted of radial and axial types. The impeller has a 45 degree backswept angle and the design running tip clearance is 5% of impeller exit height. Three-dimensional numerical analysis is performed to analyze the flows in the impeller, diffuser and deswirler considering the impeller tip clearance. Test module and rig facilities for the compressor stage performance test are designed and fabricated. The overall compressor stage performances as well as the static pressure fields on the impeller and diffuser are measured. Two diffusers of wedge and airfoil types are tested with an impeller. The calculation and test results show that flow fields downstream the deswirler at the design and off-design points are highly nonuniform and the airfoil diffuser has the better aerodynamic characteristics than those of wedge diffuser.

  11. Centrifuge modeling of buried continuous pipelines subjected to normal faulting

    Science.gov (United States)

    Moradi, Majid; Rojhani, Mahdi; Galandarzadeh, Abbas; Takada, Shiro

    2013-03-01

    Seismic ground faulting is the greatest hazard for continuous buried pipelines. Over the years, researchers have attempted to understand pipeline behavior mostly via numerical modeling such as the finite element method. The lack of well-documented field case histories of pipeline failure from seismic ground faulting and the cost and complicated facilities needed for full-scale experimental simulation mean that a centrifuge-based method to determine the behavior of pipelines subjected to faulting is best to verify numerical approaches. This paper presents results from three centrifuge tests designed to investigate continuous buried steel pipeline behavior subjected to normal faulting. The experimental setup and procedure are described and the recorded axial and bending strains induced in a pipeline are presented and compared to those obtained via analytical methods. The influence of factors such as faulting offset, burial depth and pipe diameter on the axial and bending strains of pipes and on ground soil failure and pipeline deformation patterns are also investigated. Finally, the tensile rupture of a pipeline due to normal faulting is investigated.

  12. Impeller inlet geometry effect on performance improvement for centrifugal pumps

    International Nuclear Information System (INIS)

    This research treats the effect of impeller inlet geometry on performance improvement for a boiler feed pump, who is a centrifugal pump having specific speed of 183 m.m3min-1.min-1 and close type impeller with exit diameter of 450 mm. The hydraulic performance and cavitation performance of the pump have been tested experimentally. In order to improve the pump, five impellers have been considered by extending the blade leading edge or applying much larger blade angle at impeller inlet compared with the original impeller. The 3-D turbulent flow inside those pumps has been analyzed basing on RNG k-ε turbulence model and VOF cavitation model. It is noted that the numerical results are fairly good compared with the experiments. Based on the experimental test and numerical simulation, the following conclusions can be drawn: (1) Impeller inlet geometry has important influence on performance improvement in the case of centrifugal pump. Favorite effects on performance improvement have been achieved by both extending the blade leading edge and applying much larger blade angle at impeller inlet: (2) It is suspected that the extended leading edge have favorite effect for improving hydraulic performance, and the much larger blade angle at impeller inlet have favorite effect for improving cavitation performance for the test pump: (3) Uniform flow upstream of impeller inlet is helpful for improving cavitation performance of the pump

  13. Effect of attack angle on flow characteristic of centrifugal fan

    Science.gov (United States)

    Wu, Y.; Dou, H. S.; Wei, Y. K.; Chen, X. P.; Chen, Y. N.; Cao, W. B.

    2016-05-01

    In this paper, numerical simulation is performed for the performance and internal flow of a centrifugal fan with different operating conditions using steady three-dimensional incompressible Navier-Stokes equations coupled with the RNG k-e turbulent model. The performance curves, the contours of static pressure, total pressure, radial velocity, relative streamlines and turbulence intensity at different attack angles are obtained. The distributions of static pressure and velocity on suction surface and pressure surface in the same impeller channel are compared for various attack angles. The research shows that the efficiency of the centrifugal fan is the highest when the attack angle is 8 degree. The main reason is that the vortex flow in the impeller is reduced, and the jet-wake pattern is weakened at the impeller outlet. The pressure difference between pressure side and suction side is smooth and the amplitude of the total pressure fluctuation is low along the circumferential direction. These phenomena may cause the loss reduced for the attack angle of about 8 degree.

  14. Exit flow measurements of a centrifugal pump impeller

    International Nuclear Information System (INIS)

    Discharge flows from a centrifugal pump impeller with a specific speed of 150 [rpm, m3/min, m] were experimentally investigated. A large axisymmetric collector instead of a volute casing was installed to obtain circumferentially uniform flow, i.e. without interaction of the impeller and the volute. The unsteady flow was measured at the impeller exit and vaneless diffuser using a hot film probe and a pressure transducer. The flow at impeller exit showed pronounced jet-wake flow patterns. The wake, which was on the suction/hub side at high flow rate, became enlarged pitchwisely on both the hub and the shroud side as the flow rate decreases. The pitchwise non-uniformity of the flow rapidly decreased along the downstream and the non-uniformity almost disappeared at radius ratio of 1.18 for medium flow rate. The mean vaneless diffuser flow was reasonably predicted using a one dimensional analysis when an empirical constant was used to specify the skin friction coefficient. The data can be used for a centrifugal pump impeller design and validation of CFD codes and flow modeling

  15. Numerical Study of Unsteady Flow in Centrifugal Cold Compressor

    Science.gov (United States)

    Zhang, Ning; Zhang, Peng; Wu, Jihao; Li, Qing

    In helium refrigeration system, high-speed centrifugal cold compressor is utilized to pumped gaseous helium from saturated liquid helium tank at low temperature and low pressure for producing superfluid helium or sub-cooled helium. Stall and surge are common unsteady flow phenomena in centrifugal cold compressors which severely limit operation range and impact efficiency reliability. In order to obtain the installed range of cold compressor, unsteady flow in the case of low mass flow or high pressure ratio is investigated by the CFD. From the results of the numerical analysis, it can be deduced that the pressure ratio increases with the decrease in reduced mass flow. With the decrease of the reduced mass flow, backflow and vortex are intensified near the shroud of impeller. The unsteady flow will not only increase the flow loss, but also damage the compressor. It provided a numerical foundation of analyzing the effect of unsteady flow field and reducing the flow loss, and it is helpful for the further study and able to instruct the designing.

  16. Design and Characterization of a Centrifugal Compressor Surge Test Rig

    Directory of Open Access Journals (Sweden)

    Kin Tien Lim

    2011-01-01

    Full Text Available A detailed description of a new centrifugal compressor surge test rig is presented. The objective of the design and development of the rig is to study the surge phenomenon in centrifugal compression systems and to investigate a novel method of surge control by active magnetic bearing servo actuation of the impeller axial tip clearance. In this paper, we focus on the design, initial setup, and testing of the rig. The latter two include the commissioning of the rig and the experimental characterization of the compressor performance. The behavior of the compressor during surge is analyzed by driving the experimental setup into surge. Two fundamental frequencies, 21 Hz and 7 Hz, connected to the surge oscillation in the test rig are identified, and the observed instability is categorized according to the intensity of pressure fluctuations. Based on the test results, the excited pressure waves are clearly the result of surge and not stall. Also, they exhibit the characteristics of mild and classic surge instead of deep surge. Finally, the change in the compressor performance due to variation in the impeller tip clearance is experimentally examined, and the results support the potential of the tip clearance modulation for the control of compressor surge. This is the first such demonstration of the feasibility of surge control of a compressor using active magnetic bearings.

  17. Flow Analysis of the Cleveland Clinic Centrifugal Pump

    Science.gov (United States)

    Veres, Joseph P.; Golding, Leonard A. R.; Smith, William A.; Horvath, David; Medvedev, Alexander

    1997-01-01

    An implantable ventricular assist rotordynamic blood pump is being developed by the Cleveland Clinic Foundation in cooperation with the NASA Lewis Research Center. At the nominal design condition, the pump provides blood flow at the rate of 5 liters per minute at a pressure rise of 100 mm of mercury and a rotative speed of 3000 RPM. Bench testing of the centrifugal pump in a water/glycerin mixture has provided flow and pressure data at several rotative speeds. A one-dimensional empirical based pump flow analysis computer code developed at NASA Lewis Research Center has been used in the design process to simulate the flow in the primary centrifugal pump stage. The computer model was used to size key impeller and volute geometric parameters that influence pressure rise and flow. Input requirements to the computer model include a simple representation of the pump geometry. The model estimates the flow conditions at the design and at off-design operating conditions at the impeller leading and trailing edges and the volute inlet and exit. The output from the computer model is compared to flow and pressure data obtained from bench testing.

  18. In-vitro assessment of centrifugal pumps for ventricular assist.

    Science.gov (United States)

    Jakob, H; Kutschera, Y; Palzer, B; Prellwitz, W; Oelert, H

    1990-08-01

    Currently two major types of centrifugal pumps are commercially available for ventricular assist: the Biomedicus-cone (Group I) and the Centrimed-impeller pump (now Sarns 3M) (Group II). To compare them for blood trauma and hemolysis, an in-vitro experiment was designed with a Stöckert roller pump as a standard control (Group III). The in-vitro circuit was constructed consisting of a pump head, electromagnetic flow probe, polyvinyl chloride tubing and a reservoir, identical for all groups. Human ACD blood was used for priming and was circulated with a flow rate of 2 L/min for 24 h. Blood samples were taken at 0, 1, 3, 6, 12, and 24 h and zero control values were subtracted from the resulting data per time interval. Among the 16 parameters studied, a highly significant difference in favor of Group I was found for glutamate oxalacetate transaminase (GOT) and lactate dehydrogenase (p less than 0.0001) and for the free plasma hemoglobin (p less than 0.0001) after 12 and 24 h, respectively. The hemolytic index (Allen) again was lowest for group I in contrast to Groups II and III (0.012 versus 0.060 and 1.70) after 24 h. All other parameters studied did not render significant differences between the systems tested. The authors conclude that the Biomedicus pump currently is the least traumatic centrifugal pump for ventricular assist.

  19. Platelet function and hemolysis in centrifugal pumps: in vitro investigations.

    Science.gov (United States)

    Steines, D; Westphal, D; Göbel, C; Reul, H; Rau, G

    1999-08-01

    The effects of centrifugal pumps on blood components other than erythrocytes, namely platelets and their interaction with the coagulation system, are not very well known. In a comparative study with three centrifugal pumps (BioMedicus BP-80, St. Jude Isoflow, and Sarns Delphin) and the Stockert roller pump hemolysis, platelet counts, thromboplastin and partial thromboplastin times, as well as resonance thrombography (RTG) parameters for the assessment of platelet and coagulation function were evaluated in vitro. Normalized indices of hemolysis (NIH) with ACD anticoagulation after 360 minutes were 0.008+/-0.004 (Isoflow), 0.018+/-0.017 (BP-80), 0.085+/-0.051 (Delphin), and 0.049+/-0.010 g/1001 (roller pump). Plasmatic coagulation was activated in all circuits. Platelet function was severely inhibited by the BP-80, indicated by increase in RTG platelet time to 358%+/-150% of initial values compared to 42%+/-29% (Isoflow), 40%+/-20% (Delphin), and 12%+/-10% (roller pump). Fibrin polymerization was affected similarly. The large surface area of the BP-80 leads to an extensive activation of platelets and plasminogen.

  20. LISSAT Analysis of a Generic Centrifuge Enrichment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, H; Elayat, H A; O?Connell, W J; Szytel, L; Dreicer, M

    2007-05-31

    The U.S. Department of Energy (DOE) is interested in developing tools and methods for use in designing and evaluating safeguards systems for current and future plants in the nuclear power fuel cycle. The DOE is engaging several DOE National Laboratories in efforts applied to safeguards for chemical conversion plants and gaseous centrifuge enrichment plants. As part of the development, Lawrence Livermore National Laboratory has developed an integrated safeguards system analysis tool (LISSAT). This tool provides modeling and analysis of facility and safeguards operations, generation of diversion paths, and evaluation of safeguards system effectiveness. The constituent elements of diversion scenarios, including material extraction and concealment measures, are structured using directed graphs (digraphs) and fault trees. Statistical analysis evaluates the effectiveness of measurement verification plans and randomly timed inspections. Time domain simulations analyze significant scenarios, especially those involving alternate time ordering of events or issues of timeliness. Such simulations can provide additional information to the fault tree analysis and can help identify the range of normal operations and, by extension, identify additional plant operational signatures of diversions. LISSAT analyses can be used to compare the diversion-detection probabilities for individual safeguards technologies and to inform overall strategy implementations for present and future plants. Additionally, LISSAT can be the basis for a rigorous cost-effectiveness analysis of safeguards and design options. This paper will describe the results of a LISSAT analysis of a generic centrifuge enrichment plant. The paper will describe the diversion scenarios analyzed and the effectiveness of various safeguards systems alternatives.