Mathematical modeling of thermal stresses in basic oxygen furnace hood tubes

Science.gov (United States)

Samarasekera, I. V.

1985-06-01

The stress-strain history of Basic Oxygen Furnace hood tubes during thermal cycling has been computed using heat flow and stress analyses. The steady-state temperature distribution in a transverse section of the tube was computed at a location where gas temperature in the hood could be expected to be a maximum. Calculations were performed for peak gas temperatures in the range 1950 to 2480 °C (3500 to 4500 °F). The stress-strain history of an element of material located at the center of the tube hot face was traced for three consecutive cycles using elasto-plastic finite-element analysis. It has been shown that the state of stress in the element alternates between compression and tension as the tube successively heats and cools. Yielding and plastic flow occurs at the end of each half of a given cycle. It was postulated that owing to repctitive yielding, plastic strain energy accumulates causing failure of the tubes by fatigue in the low cycle region. Using fatigue theory a conservative estimate for tube life was arrived at. In-plant observations support this mechanism of failure, and the number of cycles within which tube cracking was observed compares reasonably with model predictions. Utilizing the heat flow and stress models it was recommended that tube life could be enhanced by changing the tube material to ARMCO 17-4 pH or AISI 405 steel or alternatively reconstructing hoods with AISI 316L tubes of reduced thickness. These recommendations were based on the criterion that low-cycle fatigue failure could be averted if the magnitude of the cyclic strain could be reduced or if macroscopic plastic flow could be prevented.

The effect of water jet lancing on furnace wall tubes of high slagged deposit fuel-fired boilers

Energy Technology Data Exchange (ETDEWEB)

Vasiliev, V V; Kovalevitch, I A; Maidanik, M N [All-Union Heat Engineering Institute, Siberian Branch, Krasnoyarsk (USSR)

1990-01-01

In this paper the results of investigating the effectiveness of water jet lancing on furnace wall tubes of slagged deposits fuels fired boilers type E-500, P-64, P-67 are given. The boilers of these types are designed to burn Jugoslavian lignites are Beresovo lignites of the Kansk-Achinsk deposits. Recommendations for usage of low retractable, long retractable and long-range water blowers, depending on the design, produced in the USSR, the furnace dimension and stability of deposits are given as well.

The hydrodynamics of segmented two-phase flow in a circular tube with rapidly dissolving drops.

Science.gov (United States)

Leary, Thomas F; Ramachandran, Arun

2017-05-03

This article discusses boundary integral simulations of dissolving drops flowing through a cylindrical tube for large aspect ratio drops. The dynamics of drop dissolution is determined by three dimensionless parameters: λ, the viscosity of the drop fluid relative to the suspending fluid; Ca, the capillary number defining the ratio of the hydrodynamic force to the interfacial tension force; and k, a dissolution constant based on the velocity of dissolution. For a single dissolving drop, the velocity in the upstream region is greater than the downstream region, and for sufficiently large k, the downstream velocity can be completely reversed, particularly at low Ca. The upstream end of the drop travels faster and experiences greater deformation than the downstream end. The film thickness, δ, between the drop and the tube wall is governed by a delicate balance between dissolution and changes in the outer fluid velocity resulting from a fixed pressure drop across the tube and mass continuity. Therefore, δ, and consequently, the drop average velocity, can increase, decrease or be relatively invariant in time. For two drops flowing in succession, while low Ca drops maintain a nearly constant separation distance during dissolution, at sufficiently large Ca, for all values of k, dissolution increases the separation distance between drops. Under these conditions, the liquid segments between two adjacent drops can no longer be considered as constant volume stirred tanks. These results will guide the choices of geometry and operating parameters that will facilitate the characterization of fast gas-liquid reactions via two-phase segmented flows.

Experimental study on condensation heat transfer enhancement and pressure drop penalty factors in four microfin tubes

Energy Technology Data Exchange (ETDEWEB)

Han, D [Korea University, Seoul (Korea). Institute of Advanced Machinery Design; Lee, Kyu-Jung [Korea University, Seoul (Korea). Dept. of Mechanical Engineering

2005-08-01

Heat transfer and pressure drop characteristics of four microfin tubes were experimentally investigated for condensation of refrigerants R134a, R22, and R410A in four different test sections. The microfin tubes examined during this study consisted of 8.92, 6.46, 5.1, and 4 mm maximum inside diameter. The effect of mass flux, vapor quality, and refrigerants on condensation was investigated in terms of the heat transfer enhancement factor and the pressure drop penalty factor. The pressure drop penalty factor and the heat transfer enhancement factor showed a similar tendency for each tube at given vapor quality and mass flux. Based on the experimental data and the heat-momentum analogy, correlations for the condensation heat transfer coefficients in an annular flow regime and the frictional pressure drops are proposed. (author)

Thermal performance and pressure drop of spiral-tube ground heat exchangers for ground-source heat pump

International Nuclear Information System (INIS)

Jalaluddin; Miyara, Akio

2015-01-01

Thermal performance and pressure drop of the spiral-tube GHE were evaluated in this present work. A numerical simulation tool was used to carry out this research. The heat exchange rates per meter borehole depth of the spiral-tube GHE with various pitches and their pressure drops were compared with that of the U-tube GHE. Furthermore, a comparative analysis between a spiral pipe and straight pipe was performed. In comparison with the straight pipe, using the spiral pipe in the borehole increased the heat exchange rate to the ground per meter borehole depth. However, the pressure drop of water flow also increased due to increasing the length of pipe per meter borehole depth and its spiral geometry. The accuracy of the numerical model was verified for its pressure drop with some pressure drop correlations. The heat exchange rate and pressure drop of the GHEs are presented. As an example, the heat exchange rate per meter borehole depth of spiral pipe with 0.05 m pitch in the turbulent flow increased of 1.5 times. Its pressure drop also increased of 6 times. However, from the view point of energy efficiency, using the spiral pipe in the ground-source heat pump system gives a better performance than using the straight pipe. The heat exchange rate and pressure drop are important parameter in design of the ground-source heat pump (GSHP) system. - Highlights: • Thermal performance and pressure drop of spiral-tube GHE are presented. • Effects of spiral pitch on thermal performance and pressure drop are analyzed. • Using a spiral pipe increases heat exchange rate per meter borehole depth of GHE. • Pressure drop per meter borehole depth also increases in the spiral pipe.

Study on frictional pressure drop of steam-water two phase flow in optimized four-head internal-ribbed tube

International Nuclear Information System (INIS)

Wang Weishu; Zhu Xiaojing; Bi Qincheng; Wu Gang; Yu Shuiqing

2012-01-01

The optimized internal-ribbed tube is different from the normal internal-ribbed tube on the frictional pressure drop characteristics. The frictional pressure drop characteristics of steam-water two phase flow in horizontal four-head optimized internal-ribbed were studied under adiabatic condition. According to the experimental and calculation results, the two-phase multiplier is greatly affected by the steam quality and pressure. The two-phase multiplier increases with increasing quality, and decreases with increasing pressure. In the near-critical pressure region, the two-phase multiplier is close to 1. The frictional pressure drop of two phase flow in optimized tube is less than that in the normal tube under the same work condition. The good hydrodynamic condition could be achieved when the optimized internal-ribbed tube is used in the heat transfer equipment because the self-compensating characteristics exist due to the reduction of frictional pressure drop. (authors)

An experimental study on two-phase pressure drop in small diameter horizontal, downward inclined and vertical tubes

Directory of Open Access Journals (Sweden)

Autee Arun

2015-01-01

Full Text Available An experimental study of two-phase pressure drop in small diameter tubes orientated horizontally, vertically and at two other downward inclinations of θ= 300 and θ = 600 is described in this paper. Acrylic transparent tubes of internal diameters 4.0, 6.0, and 8.0 mm with lengths of 400 mm were used as the test section. Air-water mixture was used as the working fluid. Two-phase pressure drop was measured and compared with the existing correlations. These correlations are commonly used for calculation of pressure drop in macro and mini-microchannels. It is observed that the existing correlations are inadequate in predicting the two-phase pressure drop in small diameter tubes. Based on the experimental data, a new correlation has been proposed for predicting the two-phase pressure drop. This correlation is developed by modification of Chisholm parameter C by incorporating different parameters. It was found that the proposed correlation predicted two-phase pressure drop at satisfactory level.

Tungsten-rhenium composite tube fabricated by CVD for application in 18000C high thermal efficiency fuel processing furnace

International Nuclear Information System (INIS)

Svedberg, R.C.; Bowen, W.W.; Buckman, R.W. Jr.

1980-04-01

Chemical Vapor Deposit (CVD) rhenium was selected as the muffle material for an 1800 0 C high thermal efficiency fuel processing furnace. The muffle is exposed to high vacuum on the heater/insulation/instrumentation side and to a flowing argon-8 V/0 hydrogen gas mixture at one atmosphere pressure on the load volume side. During operation, the muffle cycles from room temperature to 1800 0 C and back to room temperature once every 24 hours. Operational life is dependent on resistance to thermal fatigue during the high temperature exposure. For a prototypical furnace, the muffle is approximately 13 cm I.D. and 40 cm in length. A small (about one-half size) rhenium closed end tube overcoated with tungsten was used to evaluate the concept. The fabrication and testing of the composite tungsten-rhenium tube and prototypic rhenium muffle is described

Boiling on a tube bundle: heat transfer, pressure drop and flow patterns

International Nuclear Information System (INIS)

Agostini, F.

2008-07-01

The complexity of the two-phase flow in a tube bundle presents important problems in the design and understanding of the physical phenomena taking place. The working conditions of an evaporator depend largely on the dynamics of the two-phase flow that in turn influence the heat exchange and the pressure drop of the system. A characterization of the flow dynamics, and possibly the identification of the flow pattern in the tube bundle, is thus expected to lead to a better understanding of the phenomena and to reveal on the mechanisms governing the tube bundle. Therefore, the present study aims at providing further insights into two-phase bundle flow through a new visualization system able to provide for the first time a view of the flow in the core of a tube bundle. In addition, the measurement of the light attenuation of a laser beam through the two-phase flow and measurement of the high frequency pressure fluctuations with a piezo-electric pressure transducer are used to characterize the flow. The design and the validation of this new instrumentation also provided a method for the detection of dry-out in tube bundles. This was achieved by a laser attenuation technique, flow visualization, and estimation of the power spectrum of the pressure fluctuation. The current investigation includes results for two different refrigerants, R134a and R236fa, three saturations temperatures T sat = 5, 10 and 15 °C, mass velocities ranging from 4 to 40 kg/sm² in adiabatic and diabatic conditions (several heat fluxes). Measurement of the local heat transfer coefficient and two-phase frictional pressure drop were obtained and utilized to improve the current prediction methods. The heat transfer and pressure drop data were supported by extensive characterization of the two-phase flow, which was to improve the understanding of the two-phase flow occurring in tube bundles. (author)

A comparison of R-22, R-134a, R-410a, and R-407c condensation performance in smooth and enhanced tubes: Part 2, Pressure drop

Energy Technology Data Exchange (ETDEWEB)

Eckels, S J; Tesene, B A

1999-07-01

This paper reports pressure drops during condensation for R-22, R-134a, R-410a, and R-407c in three enhanced tubes and one smooth tube. The test tubes were a 3/8 inch outer diameter smooth tube, a 3/8 inch outer diameter microfin tube, a 5/16 inch outer diameter microfin tube, and a 5/8 inch outer diameter microfin tube. Pressure drops are reported at four mass fluxes, at two saturation temperatures, and over a range of average qualities in the test tubes. The pressure drops for R-410a were approximately 40% lower than those of R-22 in both tubes. R-407c had 10% to 20% lower pressure drops than R-22, while 134-a had slightly larger pressure drops than R-22. The microfin tube pressure drops were, on average, 40% to 80% higher than those for the smooth tube for all refrigerants. The pressure drop penalty of the microfin tube was shown to decrease with increased quality.

Thermal–hydraulic calculation and analysis of a 600 MW supercritical circulating fluidized bed boiler with annular furnace

International Nuclear Information System (INIS)

Wang, Long; Yang, Dong; Shen, Zhi; Mao, Kaiyuan; Long, Jun

2016-01-01

Highlights: • Non-linear model of supercritical CFB boiler with annular furnace is developed. • Many empirical correlations are used to solve the model. • The thermal–hydraulic characteristics of boiler are analyzed. • The results show that the design of the annular furnace is reasonable. - Abstract: The development of supercritical Circulating Fluidized Bed (CFB) boiler has great economic and environmental value. An entirely new annular furnace structure with outer and inner ring sidewalls for supercritical CFB boiler has been put forward by Institute of Engineering Thermophysics (IET), Chinese Academy of Sciences and Dongfang Boiler Group Co., Ltd. (DBC). Its outer and inner ring furnace structure makes more water walls arranged and reduces furnace height availably. In addition, compared with other additional evaporating heating surface structures such as mid-partition and water-cooled panels, the integrative structure can effectively avoid the bed-inventory overturn and improve the penetrability of secondary air. The conditions of the 600 MW supercritical CFB boiler including capability, pressure and mass flux are harsh. In order to insure the safety of boiler operation, it is very necessary to analyze the thermal–hydraulic characteristics of water-wall system. The water-wall system with complicated pipe arrangement is regarded as a network consisting of series-parallel circuits, pressure nodes and linking circuits, which represent vertical water-wall tubes, different headers and linking tubes, respectively. Based on the mass, momentum and energy conservation, a mathematical model is built, which consists of some simultaneous nonlinear equations. The mass flux in circuits, pressure drop between headers, outer vapor temperature of water-wall system and metal temperature data of tubes at the boiler maximum continuous rating (BMCR), 75% BMCR and 30% BMCR loads are obtained by solving the mathematical model. The results show that the vertical water

Pressure Drop Correlations of Single-Phase and Two-Phase Flow in Rolling Tubes

International Nuclear Information System (INIS)

Xia-xin Cao; Chang-qi Yan; Pu-zhen Gao; Zhong-ning Sun

2006-01-01

A series of experimental studies of frictional pressure drop for single phase and two-phase bubble flow in smooth rolling tubes were carried out. The tube inside diameters were 15 mm, 25 mm and 34.5 mm respectively, the rolling angles of tubes could be set as 10 deg. and 20 deg., and the rolling periods could be set as 5 s, 10 s and 15 s. Combining with the analysis of single-phase water motion, it was found that the traditional correlations for calculating single-phase frictional coefficient were not suitable for the rolling condition. Based on the experimental data, a new correlation for calculating single-phase frictional coefficient under rolling condition was presented, and the calculations not only agreed well with the experimental data, but also could display the periodically dynamic characteristics of frictional coefficients. Applying the new correlation to homogeneous flow model, two-phase frictional pressure drop of bubble flow in rolling tubes could be calculated, the results showed that the relative error between calculation and experimental data was less than ± 25%. (authors)

Boiling on a tube bundle: heat transfer, pressure drop and flow patterns

International Nuclear Information System (INIS)

Royen Van, E.

2011-11-01

The complexity of two-phase flow boiling on a tube bundle presents many challenges to the understanding of the physical phenomena taking place. It is important to quantify these numerous heat flow mechanisms in order to better describe the performance of tube bundles as a function of the operational conditions. In the present study, the bundle boiling facility at the Laboratory of Heat and Mass Transfer (LTCM) was modified to obtain high-speed videos to characterise the two-phase regimes and some bubble dynamics of the boiling process. It was then used to measure heat transfer on single tubes and in bundle boiling conditions. Pressure drop measurements were also made during adiabatic and diabatic bundle conditions. New enhanced boiling tubes from Wolverine Tube Inc. (Turbo-B5) and the Wieland-Werke AG (Gewa-B5) were investigated using R134a and R236fa as test fluids. The tests were carried out at saturation temperatures T sat of 5 °C and 15 °C, mass flow rates from 4 to 35 kg/m 2 s and heat fluxes from 15 to 70 kW/m 2 , typical of actual operating conditions. The flow pattern investigation was conducted using visual observations from a borescope inserted in the middle of the bundle. Measurements of the light attenuation of a laser beam through the intertube two-phase flow and local pressure fluctuations with piezo-electric pressure transducers were also taken to further help in characterising the complex flow. Pressure drop measurements and data reduction procedures were revised and used to develop new, improved frictional pressure drop prediction methods for adiabatic and diabatic two-phase conditions. The physical phenomena governing the enhanced tube evaporation process and their effects on the performance of tube bundles were investigated and insight gained. A new method based on a theoretical analysis of thin film evaporation was used to propose a new correlating parameter. A large new database of local heat transfer coefficients were obtained and then

Creeping motion of long bubbles and drops in capillary tubes

DEFF Research Database (Denmark)

Westborg, Henrik; Hassager, Ole

1989-01-01

The flow of inviscid bubbles and viscous drops in capillary tubes has been simulated by a Galerkin finite element method with surface tension included at the bubble/liquid interface. The results show good agreement with published experimental results. At low capillary numbers the front and the rear...... of the bubble are nearly spherical. As the capillary number increases the thickness of the wetting film between the tube wall and the bubble increases, and the bubble assumes a more slender shape with a characteristic bump at the rear. Recirculations are found in front and behind the bubble, which disappear...

Pressure drop-flow rate curves for single-phase steam in Combustion Engineering type steam generator U-tubes during severe accidents

Energy Technology Data Exchange (ETDEWEB)

Fynan, Douglas A.; Ahn, Kwang-Il, E-mail: kiahn@kaeri.re.kr

2016-12-15

Highlights: • Pressure drop-flow rate curves for superheated steam in U-tubes were generated. • Forward flow of hot steam is favored in the longer and taller U-tubes. • Reverse flow of cold steam is favored in short U-tubes. • Steam generator U-tube bundle geometry and tube diameter are important. • Need for correlation development for natural convention heat transfer coefficient. - Abstract: Characteristic pressure drop-flow rate curves are generated for all row numbers of the OPR1000 steam generators (SGs), representative of Combustion Engineering (CE) type SGs featuring square bend U-tubes. The pressure drop-flow rate curves are applicable to severe accident natural circulations of single-phase superheated steam during high pressure station blackout sequences with failed auxiliary feedwater and dry secondary side which are closely related to the thermally induced steam generator tube rupture event. The pressure drop-flow rate curves which determine the recirculation rate through the SG tubes are dependent on the tube bundle geometry and hydraulic diameter of the tubes. The larger CE type SGs have greater variation of tube length and height as a function of row number with forward flow of steam favored in the longer and taller high row number tubes and reverse flow favored in the short low row number tubes. Friction loss, natural convection heat transfer coefficients, and temperature differentials from the primary to secondary side are dominant parameters affecting the recirculation rate. The need for correlation development for natural convection heat transfer coefficients for external flow over tube bundles currently not modeled in system codes is discussed.

Numerical study on turbulent heat transfer and pressure drop of nanofluid in coiled tube-in-tube heat exchangers

International Nuclear Information System (INIS)

Aly, Wael I.A.

2014-01-01

Highlights: • The performance of helically coiled tube heat exchanger using nanofluid is modeled. • The 3D turbulent flow and conjugate heat transfer of CTITHE are solved using FVM. • The effects of nanoparticle concentration and curvature ratio are investigated. • The Gnielinski correlation for Nu for turbulent flow in helical tubes can be used for water-based Al 2 O 3 nanofluid. - Abstract: A computational fluid dynamics (CFD) study has been carried out to study the heat transfer and pressure drop characteristics of water-based Al 2 O 3 nanofluid flowing inside coiled tube-in-tube heat exchangers. The 3D realizable k–ε turbulent model with enhanced wall treatment was used. Temperature dependent thermophysical properties of nanofluid and water were used and heat exchangers were analyzed considering conjugate heat transfer from hot fluid in the inner-coiled tube to cold fluid in the annulus region. The overall performance of the tested heat exchangers was assessed based on the thermo-hydrodynamic performance index. Design parameters were in the range of; nanoparticles volume concentrations 0.5%, 1.0% and 2.0%, coil diameters 0.18, 0.24 and 0.30 m, inner tube and annulus sides flow rates from 2 to 5 LPM and 10 to 25 LPM, respectively. Nanofluid flows inside inner tube side or annular side. The results obtained showed a different behavior depending on the parameter selected for the comparison with the base fluid. Moreover, when compared at the same Re or Dn, the heat transfer coefficient increases by increasing the coil diameter and nanoparticles volume concentration. Also, the friction factor increases with the increase in curvature ratio and pressure drop penalty is negligible with increasing the nanoparticles volume concentration. Conventional correlations for predicting average heat transfer and friction factor in turbulent flow regime such as Gnielinski correlation and Mishra and Gupta correlation, respectively, for helical tubes are also valid for

Characterization of calcium carbonate sorbent particle in furnace environment

Energy Technology Data Exchange (ETDEWEB)

Lee, Kang Soo [Aerosol and Particle Technology Laboratory, Department of Mechanical Engineering, KAIST 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Jung, Jae Hee [Environment Sensor System Research Center, KIST 39-1 Hawolgok-dong, Seongbuk-gu, Seoul, 136-791 (Korea, Republic of); Keel, Sang In; Yun, Jin Han; Min, Tai Jin [Environmental Systems Research Division, KIMM 104 Sinseongno, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of); Kim, Sang Soo, E-mail: sskim@kaist.ac.kr [Aerosol and Particle Technology Laboratory, Department of Mechanical Engineering, KAIST 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of)

2012-07-01

The oxy-fuel combustion system is a promising technology to control CO{sub 2} and NO{sub X} emissions. Furthermore, sulfation reaction mechanism under CO{sub 2}-rich atmospheric condition in a furnace may lead to in-furnace desulfurization. In the present study, we evaluated characteristics of calcium carbonate (CaCO{sub 3}) sorbent particles under different atmospheric conditions. To examine the physical/chemical characteristics of CaCO{sub 3}, which is used as a sorbent particle for in-furnace desulfurization in the oxy-fuel combustion system, they were injected into high temperature drop tube furnace (DTF). Experiments were conducted at varying temperatures, residence times, and atmospheric conditions in a reactor. To evaluate the aerosolizing characteristics of the CaCO{sub 3} sorbent particle, changes in the size distribution and total particle concentration between the DTF inlet and outlet were measured. Structural changes (e.g., porosity, grain size, and morphology) of the calcined sorbent particles were estimated by BET/BJH, XRD, and SEM analyses. It was shown that sorbent particles rapidly calcined and sintered in the air atmosphere, whereas calcination was delayed in the CO{sub 2} atmosphere due to the higher CO{sub 2} partial pressure. Instead, the sintering effect was dominant in the CO{sub 2} atmosphere early in the reaction. Based on the SEM images, it was shown that the reactions of sorbent particles could be explained as a grain-subgrain structure model in both the air and CO{sub 2} atmospheres.

Characterization of calcium carbonate sorbent particle in furnace environment

International Nuclear Information System (INIS)

Lee, Kang Soo; Jung, Jae Hee; Keel, Sang In; Yun, Jin Han; Min, Tai Jin; Kim, Sang Soo

2012-01-01

The oxy-fuel combustion system is a promising technology to control CO 2 and NO X emissions. Furthermore, sulfation reaction mechanism under CO 2 -rich atmospheric condition in a furnace may lead to in-furnace desulfurization. In the present study, we evaluated characteristics of calcium carbonate (CaCO 3 ) sorbent particles under different atmospheric conditions. To examine the physical/chemical characteristics of CaCO 3 , which is used as a sorbent particle for in-furnace desulfurization in the oxy-fuel combustion system, they were injected into high temperature drop tube furnace (DTF). Experiments were conducted at varying temperatures, residence times, and atmospheric conditions in a reactor. To evaluate the aerosolizing characteristics of the CaCO 3 sorbent particle, changes in the size distribution and total particle concentration between the DTF inlet and outlet were measured. Structural changes (e.g., porosity, grain size, and morphology) of the calcined sorbent particles were estimated by BET/BJH, XRD, and SEM analyses. It was shown that sorbent particles rapidly calcined and sintered in the air atmosphere, whereas calcination was delayed in the CO 2 atmosphere due to the higher CO 2 partial pressure. Instead, the sintering effect was dominant in the CO 2 atmosphere early in the reaction. Based on the SEM images, it was shown that the reactions of sorbent particles could be explained as a grain–subgrain structure model in both the air and CO 2 atmospheres.

Brazing open cell reticulated copper foam to stainless steel tubing with vacuum furnace brazed gold/indium alloy plating

Science.gov (United States)

Howard, Stanley R [Windsor, SC; Korinko, Paul S [Aiken, SC

2008-05-27

A method of fabricating a heat exchanger includes brush electroplating plated layers for a brazing alloy onto a stainless steel tube in thin layers, over a nickel strike having a 1.3 .mu.m thickness. The resultant Au-18 In composition may be applied as a first layer of indium, 1.47 .mu.m thick, and a second layer of gold, 2.54 .mu.m thick. The order of plating helps control brazing erosion. Excessive amounts of brazing material are avoided by controlling the electroplating process. The reticulated copper foam rings are interference fit to the stainless steel tube, and in contact with the plated layers. The copper foam rings, the plated layers for brazing alloy, and the stainless steel tube are heated and cooled in a vacuum furnace at controlled rates, forming a bond of the copper foam rings to the stainless steel tube that improves heat transfer between the tube and the copper foam.

Flow condensation pressure drop characteristics of R410A-oil mixture inside small diameter horizontal microfin tubes

Energy Technology Data Exchange (ETDEWEB)

Huang, Xiangchao; Ding, Guoliang; Hu, Haitao; Zhu, Yu [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Gao, Yifeng [International Copper Association Shanghai Office, Shanghai 200020 (China); Deng, Bin [Institute of Heat Transfer Technology, Golden Dragon Precise Copper Tube Group Inc., Shanghai 200135 (China)

2010-11-15

Flow condensation pressure drop characteristics of R410A-oil mixture inside small diameter (5.0 mm and 4.0 mm O.D.) horizontal microfin tubes were investigated experimentally covering nominal oil concentrations from 0% to 5%. The research results indicate that, comparing with the frictional pressure drop of pure R410A, the frictional pressure drop of R410A-oil mixture may decrease by maximum of 18% when the vapor quality is lower than 0.6, and increase by maximum of 13% when the vapor quality is higher than 0.6. A new frictional pressure drop correlation for R410A-oil mixture flow condensation inside microfin tubes is developed based on the refrigerant-oil mixture properties, and can agree with 94% of the experimental data within a deviation of -30% to +30%. (author)

Characteristics of two-phase flow pattern transitions and pressure drop of five refrigerants in horizontal circular small tubes

Energy Technology Data Exchange (ETDEWEB)

Pamitran, A.S. [Department of Mechanical Engineering, University of Indonesia, Kampus Baru UI, Depok 16424 (Indonesia); Choi, Kwang-Il [Graduate School, Chonnam National University, San 96-1, Dunduk-Dong, Yeosu, Chonnam 550-749 (Korea); Oh, Jong-Taek [Department of Refrigeration and Air Conditioning Engineering, Chonnam National University, San 96-1, Dunduk-Dong, Yeosu, Chonnam 550-749 (Korea); Hrnjak, Pega [Department of Mechanical Science and Engineering, ACRC, University of Illinois at Urbana-Champaign, 1206 West Green Street, Urbana, IL 61801 (United States)

2010-05-15

An experimental investigation on the characteristics of two-phase flow pattern transitions and pressure drop of R-22, R-134a, R-410A, R-290 and R-744 in horizontal small stainless steel tubes of 0.5, 1.5 and 3.0 mm inner diameters is presented. Experimental data were obtained over a heat flux range of 5-40 kW/m{sup 2}, mass flux range of 50-600 kg/(m{sup 2} s), saturation temperature range of 0-15 C, and quality up to 1.0. Experimental data were evaluated with Wang et al. and Wojtan et al. [Wang, C.C., Chiang, C.S., Lu, D.C., 1997. Visual observation of two-phase flow pattern of R-22, R-134a, and R-407C in a 6.5-mm smooth tube. Exp. Therm. Fluid Sci. 15, 395-405; Wojtan, L., Ursenbacher, T., Thome, J.R., 2005. Investigation of flow boiling in horizontal tubes: part I - a new diabatic two-phase flow pattern map. Int. J. Heat Mass Transfer 48, 2955-2969.] flow pattern maps. The effects of mass flux, heat flux, saturation temperature and inner tube diameter on the pressure drop of the working refrigerants are reported. The experimental pressure drop was compared with the predictions from some existing correlations. A new two-phase pressure drop model that is based on a superposition model for two-phase flow boiling of refrigerants in small tubes is presented. (author)

Condensation heat transfer and pressure drop of R-410A in flat aluminum multi-port tubes

Science.gov (United States)

Kim, Nae-Hyun

2018-02-01

Brazed heat exchangers with aluminum flat multi-port tubes are being used as condensers of residential air-conditioners. In this study, R-410A condensation tests were conducted in four multi-port tubes having a range of hydraulic diameter (0.78 ≤ Dh ≤ 0.95 mm). The test range covered the mass flux from 100 to 400 kg/m2 s and the heat flux at 3 kW/m2, which are typical operating conditions of residential air conditioners. Results showed that both the heat transfer coefficient and the pressure drop increased as the hydraulic diameter decreased. The effect of hydraulic diameter on condensation heat transfer was much larger than the predictions of existing correlations for the range of investigation. Comparison of the data with the correlations showed that some macro-channel tube correlations and mini-channel tube correlations reasonably predicted the heat transfer coefficient. However, macro-channel correlations highly overpredicted the pressure drop data.

Multikilowatt variable frequency microwave furnace

International Nuclear Information System (INIS)

Bible, D.W.; Lauf, R.J.; Everleigh, C.A.

1992-01-01

In this paper, the authors describe a new type of microwave processing furnace in which the frequency can be varied continuously from 4 to 8 GHz and the power level varied from zero up to 2.5 kW. The extraordinary bandwidth of this furnace is achieved by using a traveling wave tube (TWT) amplifier originally developed for electronic warfare applications. The TWT is a linear beam device characterized by a traveling electromagnetic wave that continuously extracts energy longitudinally along the path of an electron beam. The TWT, unlike other microwave tubes such as the magnetron, klystron, gyrotron, and others, does not depend upon resonant RF fields and is therefore capable of wide bandwidth operation.operation

Numerical studies on heat transfer and pressure drop characteristics of flat finned tube bundles with various fin materials

Science.gov (United States)

Peng, Y.; Zhang, S. J.; Shen, F.; Wang, X. B.; Yang, X. R.; Yang, L. J.

2017-11-01

The air-cooled heat exchanger plays an important role in the field of industry like for example in thermal power plants. On the other hand, it can be used to remove core decay heat out of containment passively in case of a severe accident circumstance. Thus, research on the performance of fins in air-cooled heat exchangers can benefit the optimal design and operation of cooling systems in nuclear power plants. In this study, a CFD (Computational Fluid Dynamic) method is implemented to investigate the effects of inlet velocity, fin spacing and tube pitch on the flow and the heat transfer characteristics of flat fins constructed of various materials (316L stainless steel, copper-nickel alloy and aluminium). A three dimensional geometric model of flat finned tube bundles with fixed longitudinal tube pitch and transverse tube pitch is established. Results for the variation of the average convective heat transfer coefficient with respect to cooling air inlet velocity, fin spacing, tube pitch and fin material are obtained, as well as for the pressure drop of the cooling air passing through finned tube. It is shown that the increase of cooling air inlet velocity results in enhanced average convective heat transfer coefficient and decreasing pressure drop. Both fin spacing and tube pitch engender positive effects on pressure drop and have negative effects on heat transfer characteristics. Concerning the fin material, the heat transfer performance of copper-nickel alloy is superior to 316L stainless steel and inferior to aluminium.

Study on drop pressure and flow distribution of double-tube heat exchanger

International Nuclear Information System (INIS)

Liu Junqiang; Chen Minghui; Hu Yumin; Li Rizhu; Kong Dechun; Zhang Weijie

2007-01-01

The parallel connection channel pressure drop characters of the double-tube bundle heat exchange were experimentally investigated in this paper in order to find out how the flow of the heat exchanger is distributed and then to optimize the structure of heat exchanger according to the flow distribution. A double-tube bundle heat exchanger was built according to the similarity criteria. The experiment system was also built to test the optimization of the heat exchanger. The experiment results reveal that the calculating model is reliable and decreasing pipe space to optimize the heat exchanger is reasonable. (authors)

Numerical study of pressure drop and heat transfer from circular and cam-shaped tube bank in cross-flow of nanofluid

International Nuclear Information System (INIS)

Mirabdolah Lavasani, Arash; Bayat, Hamidreza

2016-01-01

Highlights: • Flow around non-circular and circular shaped tube bank is studied. • Effect of using Al_2O_3-water nanofluid on flow and heat transfer is discussed. • Tubes are with in-line and staggered arrangement. • Pressure drop of non-circular tube is noticeably lower that circular tube. - Abstract: Flow and heat transfer of nanofluid inside circular and cam-shaped tube bank is studied numerically. Reynolds number for cam-shaped tube bank is defined based on equivalent diameter of circular tube and varies in range of 100 ⩽ Re_D ⩽ 400. Nanofluid is made by adding Al_2O_3 nanoparticle with volume fraction of 1–7% to pure water. Results show using nanofluid results in higher heat transfer rate for both circular tube bank and cam-shaped tube bank. Also, staggered arrangement has higher heat transfer for both circular and cam-shaped tube bank. Pressure drop from cam-shaped tube bank is substantially lower than circular tube bank for all range of Reynolds number and volume fraction.

Evaporation heat transfer and pressure drop of R-410A in three 7.0 mm O.D. microfin tubes having different inside geometries

International Nuclear Information System (INIS)

Kim, Nae Hyun

2015-01-01

R-410A evaporation heat transfer and pressure drop data are provided for three 7.0 mm O.D. microfin tubes. The microfin tubes had different helix angle, fin height and fin apex angle. Tests were conducted for a range of quality (0.2 ∼ 0.8), mass flux (216 ∼ 390 kg/m 2 s), heat flux (9 ∼ 17 kW/m 2 ) and saturation temperature (8 ∼ 12 .deg. C). It was found that three microfin tubes yielded approximately the same heat transfer coefficients. Microfin tube with larger inter-fin spacing or smaller helix angle yielded lager pressure drop. Both heat transfer coefficient and pressure drop increased as mass flux or quality increased. However, they decreased as saturation temperature increased. The range of heat transfer enhancement factor (1.37 ∼ 1.97) was comparable with that of pressure drop penalty factor (1.22 ∼ 1.77). Data are compared with available heat transfer and pressure drop correlations

Sealed rotary hearth furnace with central bearing support

Science.gov (United States)

Docherty, James P.; Johnson, Beverly E.; Beri, Joseph

1989-01-01

The furnace has a hearth which rotates inside a stationary closed chamber and is supported therein on vertical cylindrical conduit which extends through the furnace floor and is supported by a single center bearing. The charge is deposited through the furnace roof on the rim of the hearth as it rotates and is moved toward the center of the hearth by rabbles. Externally generated hot gases are introduced into the furnace chamber below the hearth and rise through perforations in the hearth and up through the charge. Exhaust gases are withdrawn through the furnace roof. Treated charge drops from a center outlet on the hearth into the vertical cylindrical conduit which extends downwardly through the furnace floor to which it is also sealed.

Heat transfer and pressure drop in a tube bank inclined with respect to the flow

Energy Technology Data Exchange (ETDEWEB)

Yanez Moreno, A.A.

1985-01-01

This research is intended to lend understanding and to quantify the heat-transfer and fluid-flow characteristics for yawed tube banks in both staggered and in-line arrays. The investigated range of yaw angle was from 90 (crossflow) to 45/sup 0/, while the freestream Reynolds number (based on the tube diameter) ranged between 7000 and 45,000. The transverse and longitudinal center-to-center distances between the tubes were S/sub T//D = S/sub L//D = 2, respectively. The heat-transfer experiments were carried out on a row-by-row basis. Pressure drop measurements were made not only upstream and downstream of the tube bank but also within it. The patterns of fluid flow adjacent to the tubes were visualized using the oil-lampblack technique. A detailed study was carried out to determine the heat-transfer characteristics of a yawed single cylinder. The yaw angle range was between 90 and 30/sup 0/, and flow visualization was also performed. The pressure measurements showed that the overall dimensionless pressure drop for the staggered array is higher than that for the in-line array for a given Reynolds number or yaw. The flow-visualization patterns showed that the boundary layer separation depends on the yaw angle. For the single cylinder, the Nusselt number varied with the yaw angle in an undulating manner and did not correlate with the Independence Principle.

Flow and pressure drop fluctuations in a vertical tube subject to low frequency oscillations

International Nuclear Information System (INIS)

Pendyala, Rajashekhar; Jayanti, Sreenivas; Balakrishnan, A.R.

2008-01-01

Heat transfer and other equipment mounted on off-shore platforms may be subjected to low frequency oscillations. The effect of these oscillations, typically in the frequency range of 0.1-1 Hz, on the flow rate and pressure drop in a vertical tube has been studied experimentally in the present work. A 1.75 m-long vertical tube of inner diameter 0.016 m was mounted on a plate and the whole plate was subjected to oscillations in the vertical plane using a mechanical simulator capable of providing low frequency oscillations in the range of 8-30 cycles/min at an amplitude of 0.125 m. The effect of the oscillations on the flow rate and the pressure drop has been measured systematically in the Reynolds number range 500-6500. The induced flow rate fluctuations were found to be dependent on the Reynolds number with stronger fluctuations at lower Reynolds numbers. The effective friction factor, based on the mean pressure drop and the mean flow rate, was also found to be higher than expected. Correlations have been developed to quantify this Reynolds number dependence

Flow and pressure drop fluctuations in a vertical tube subject to low frequency oscillations

Energy Technology Data Exchange (ETDEWEB)

Pendyala, Rajashekhar; Jayanti, Sreenivas [Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Balakrishnan, A.R. [Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036 (India)], E-mail: arbala@iitm.ac.in

2008-01-15

Heat transfer and other equipment mounted on off-shore platforms may be subjected to low frequency oscillations. The effect of these oscillations, typically in the frequency range of 0.1-1 Hz, on the flow rate and pressure drop in a vertical tube has been studied experimentally in the present work. A 1.75 m-long vertical tube of inner diameter 0.016 m was mounted on a plate and the whole plate was subjected to oscillations in the vertical plane using a mechanical simulator capable of providing low frequency oscillations in the range of 8-30 cycles/min at an amplitude of 0.125 m. The effect of the oscillations on the flow rate and the pressure drop has been measured systematically in the Reynolds number range 500-6500. The induced flow rate fluctuations were found to be dependent on the Reynolds number with stronger fluctuations at lower Reynolds numbers. The effective friction factor, based on the mean pressure drop and the mean flow rate, was also found to be higher than expected. Correlations have been developed to quantify this Reynolds number dependence.

Condensation heat transfer and pressure drop of R-410A in a 7.0 mm O.D. microfin tube at low mass fluxes

Science.gov (United States)

Kim, Nae-Hyun

2016-12-01

R-410A condensation heat transfer and pressure drop data are provided for a 7.0 mm O.D. microfin tube at low mass fluxes (50-250 kg/m2 s). The heat transfer coefficient of the microfin tube shows a minimum behavior with the mass flux. At a low mass flux, where flow pattern is stratified, condensation induced by surface tension by microfins overwhelms condensation induced by shear, and the heat transfer coefficient decreases as mass flux increases. At a high mass flux, where flow pattern is annular, condensation induced by shear governs the heat transfer, and the heat transfer coefficient increases as mass flux increases. The pressure drop of the microfin tube is larger than that of the smooth tube at the annular flow regime. On the contrary, the pressure drop of the smooth tube is larger than that of the microfin tube at the stratified flow regime.

Energy conservation in industrial furnaces with vertical radiation roofs of reinforced refractory concrete

Energy Technology Data Exchange (ETDEWEB)

Grafe, E

1981-01-01

The paper discusses static systems for furnaces of reinforced refractory concrete, the temperature field over the finned-plate cross section, the calculation of the reinforced refractory concrete, experimental application in a flat open-hearth pusher furnace, a pack heating furnace, and a sinker furnace. There are cantilever beam plates, frames, and drop ceiling elements particularly suited for efficient use of high-performance burners.

The Study of Heat Treatment Effects on Chromium Carbide Precipitation of 35Cr-45Ni-Nb Alloy for Repairing Furnace Tubes

Directory of Open Access Journals (Sweden)

Nakarin Srisuwan

2016-01-01

Full Text Available This paper presents a specific kind of failure in ethylene pyrolysis furnace tubes. It considers the case in which the tubes made of 35Cr-45Ni-Nb high temperature alloy failed to carburization, causing creep damage. The investigation found that used tubes became difficult to weld repair due to internal carburized layers of the tube. The microstructure and geochemical component of crystallized carbide at grain boundary of tube specimens were characterized by X-ray diffractometer (XRD, scanning electron microscopy (SEM with back-scattered electrons mode (BSE, and energy dispersive X-ray spectroscopy (EDS. Micro-hardness tests was performed to determine the hardness of the matrix and the compounds of new and used tube material. The testing result indicated that used tubes exhibited a higher hardness and higher degree of carburization compared to those of new tubes. The microstructure of used tubes also revealed coarse chromium carbide precipitation and a continuous carbide lattice at austenite grain boundaries. However, thermal heat treatment applied for developing tube weld repair could result in dissolving or breaking up chromium carbide with a decrease in hardness value. This procedure is recommended to improve the weldability of the 35Cr-45Ni-Nb used tubes alloy.

Measurement of subcooled boiling pressure drop and local heat transfer coefficient in horizontal tube under LPLF conditions

International Nuclear Information System (INIS)

Baburajan, P.K.; Bisht, G.S.; Gupta, S.K.; Prabhu, S.V.

2013-01-01

Highlights: ► Measured subcooled boiling pressure drop and local heat transfer coefficient in horizontal tubes. ► Infra-red thermal imaging is used for wall temperature measurement. ► Developed correlations for pressure drop and local heat transfer coefficient. -- Abstract: Horizontal flow is commonly encountered in boiler tubes, refrigerating equipments and nuclear reactor fuel channels of pressurized heavy water reactors (PHWR). Study of horizontal flow under low pressure and low flow (LPLF) conditions is important in understanding the nuclear core behavior during situations like LOCA (loss of coolant accidents). In the present work, local heat transfer coefficient and pressure drop are measured in a horizontal tube under LPLF conditions of subcooled boiling. Geometrical parameters covered in this study are diameter (5.5 mm, 7.5 mm and 9.5 mm) and length (550 mm, 750 mm and 1000 mm). The operating parameters varied are mass flux (450–935 kg/m 2 s) and inlet subcooling (29 °C, 50 °C and 70 °C). Infra-red thermography is used for the measurement of local wall temperature to estimate the heat transfer coefficient in single phase and two phase flows with water as the working medium at atmospheric pressure. Correlation for single phase diabatic pressure drop ratio (diabatic to adiabatic) as a function of viscosity ratio (wall temperature to fluid temperature) is presented. Correlation for pressure drop under subcooled boiling conditions as a function of Boiling number (Bo) and Jakob number (Ja) is obtained. Correlation for single phase heat transfer coefficient in the thermal developing region is presented as a function of Reynolds number (Re), Prandtl number (Pr) and z/d (ratio of axial length of the test section to diameter). Correlation for two phase heat transfer coefficient under subcooled boiling condition is developed as a function of boiling number (Bo), Jakob number (Ja) and Prandtl number (Pr)

Flow instability research on steam generator with straight double-walled heat transfer tube for FBR. Pressure drop under high pressure condition

International Nuclear Information System (INIS)

Liu, Wei; Tamai, Hidesada; Yoshida, Hiroyuki; Takase, Kazuyuki; Hayafune, Hiroki; Futagami, Satoshi; Kisohara, Naoyuki

2008-01-01

For the Steam Generator (SG) with straight double-walled heat transfer tube that used in sodium cooled Faster Breeder Reactor, flow instability is one of the most important items need researching. As the first step of the research, thermal hydraulics experiments were performed under high pressure condition in JAEA with using a straight tube. Pressure drop, heat transfer coefficients and void fraction data were derived. This paper evaluates the pressure drop data with TRAC-BF1 code. The Pffan's correlation for single phase flow and the Martinelli-Nelson's two-phase flow multiplier are found can be well predicted the present pressure drop data under high pressure condition. (author)

Volatile release and particle formation characteristics of injected pulverized coal in blast furnaces

International Nuclear Information System (INIS)

Chen, Wei-Hsin; Du, Shan-Wen; Yang, Tsung-Han

2007-01-01

Volatiles release and particle formation for two kinds of pulverized coals (a high volatile bituminous coal and a low volatile bituminous coal) in a drop tube furnace are investigated to account for the reactions of pulverized coal injected in blast furnaces. Two different sizes of feed particles are considered; one is 100-200 mesh and the other is 200-325 mesh. By evaluating the R-factor, the devolatilization extent of the larger feed particles is found to be relatively poor. However, the swelling behavior of individual or two agglomerated particles is pronounced, which is conducive to gasification of the chars in blast furnaces. In contrast, for the smaller feed particles, volatiles liberated from the coal particles can be improved in a significant way as a result of the amplified R-factor. This enhancement can facilitate the performance of gas phase combustion. Nevertheless, the residual char particles are characterized by agglomeration, implying that the reaction time of the char particles will be lengthened, thereby increasing the possibility of furnace instability. Double peak distributions in char particle size are observed in some cases. This possibly results from the interaction of the plastic state and the blowing effect at the particle surface. Considering the generation of tiny aerosols composed of soot particles and tar droplets, the results indicate that their production is highly sensitive to the volatile matter and elemental oxygen contained in the coal. Comparing the reactivity of the soot to that of the unburned char, the former is always lower than the latter. Consequently, the lower is the soot formation, the better is the blast furnace stability

Numerical study on pressure drop and heat transfer for designing sodium-to-air heat exchanger tube banks on advanced sodium-cooled fast reactor

International Nuclear Information System (INIS)

Kang, Hie-Chan; Eoh, Jae-Hyuk; Cha, Jae-Eun; Kim, Seong-O.

2013-01-01

Highlights: ► Numerical simulation for the heat flow characteristic of the sodium-to-air heat exchanger (AHX) and tube banks. ► Parallelogram tube banks showed almost similar thermal and hydraulic characteristics to the rectangular tube banks. ► Pressure drop and heat transfer of the staggered and rectangular tube banks compared with Zhukauskas’ correlation. ► AHX was modeled as porous media and suggested design guide to enhance the performance. - Abstract: A numerical study is performed to investigate the thermal and hydraulic characteristics and build up design model of the AHX (sodium-to-air heat exchanger) unit of a sodium-cooled fast reactor. Helical-coiled tube banks in the AHX are modeled as porous media and simulated heat and momentum transfer by a commercial program. Two-dimensional flow characteristic appears differently at the inlet region of the AHX annulus, and the required length of the inlet region is shorter for an inlet having a 45 degree chamber or a round shape than for one with a perpendicular corner. Pressure drop and heat transfer coefficient for rectangular, parallelogram and staggered tube banks as the main components of the AHX are evaluated and discussed. Pressure drop and heat transfer shows similar trends and underestimated values, respectively, when compared with Zhukauskas empirical correlations. The parallelogram tube bank shows similar results to the rectangular arrangement.

Effect of superficial velocity on vaporization pressure drop with propane in horizontal circular tube

Science.gov (United States)

Novianto, S.; Pamitran, A. S.; Nasruddin, Alhamid, M. I.

2016-06-01

Due to its friendly effect on the environment, natural refrigerants could be the best alternative refrigerant to replace conventional refrigerants. The present study was devoted to the effect of superficial velocity on vaporization pressure drop with propane in a horizontal circular tube with an inner diameter of 7.6 mm. The experiments were conditioned with 4 to 10 °C for saturation temperature, 9 to 20 kW/m2 for heat flux, and 250 to 380 kg/m2s for mass flux. It is shown here that increased heat flux may result in increasing vapor superficial velocity, and then increasing pressure drop. The present experimental results were evaluated with some existing correlations of pressure drop. The best prediction was evaluated by Lockhart-Martinelli (1949) with MARD 25.7%. In order to observe the experimental flow pattern, the present results were also mapped on the Wang flow pattern map.

Determination of vanadium in sea water by graphite furnace atomic absorption spectrometry with a tube coated with pyrolytic graphite

International Nuclear Information System (INIS)

Shimizu, Tokuo; Sakai, Kaoru

1981-01-01

The trace amount of vanadium in sea water was determined by graphite furnace atomic absorption spectrometry with a tube coated with pyrolytic graphite. To correct the background absorption, a deuterium lamp with a higher-brilliant thermal cathode was used. The sensitivity for vanadium increased 10 -- 20 fold by the use of the tube coated with pyrolytic graphite, and the utility lifetime of the tube was greatly extended. Vanadium(V) - 4-(2-pyridylazo)resorcinol (PAR) complexes were extracted into chloroform as an ion-pair with benzyldimethyltetradecylammonium (Zephiramine) cation alternatively. The sample of sea water, which was made to 0.1 N in sulfuric acid and 0.1% in hydrogen peroxide, was loaded onto the column of Dowex 1-X 4 resin (SO 4 2- -form). Vanadium was then eluted from the resin with 1 N sulfuric acid-0.1% hydrogen peroxide or 1 N hydrochloric acid-0.1% hydrogen peroxide evaporated to dry. After dissolution of the elute in 0.2 N nitric acid, vanadium was extracted. Secondly, the sample of sea water was adjusted to pH 5.0, and loaded onto the column of Chelex-100 resin. Vanadium was eluted from the resin with 2 N ammonia. The above two methods took much time, but the coprecipitation method was not so and recommended for the determination of vanadium in sea water. Vanadium was coprecipitated with iron(III) hydroxide-hydrous titanium(IV) oxide at pH 6.0. The precipitate was digested with nitric acid-hydrogen peroxide. The solution was diluted to 50 ml with water. The resulting solutions were employed to determine the vanadium concentration by the graphite furnace atomic absorption measurement. The trace amounts of vanadium in various kinds of the coastal sea water were determined by the coprecipitation method. (author)

Pressure drop and stability of flow in Archimedean spiral tube with transverse corrugations

Directory of Open Access Journals (Sweden)

Đorđević Milan

2016-01-01

Full Text Available Isothermal pressure drop experiments were carried out for the steady Newtonian fluid flow in Archimedean spiral tube with transverse corrugations. Pressure drop correlations and stability criteria for distinguishing the flow regimes have been obtained in a continuous Reynolds number range from 150 to 15 000. The characterizing geometrical groups which take into account all the geometrical parameters of Archimedean spiral and corrugated pipe has been acquired. Before performing experiments over the Archimedean spiral, the corrugated straight pipe having high relative roughness e/d = 0.129 of approximately sinusoidal type was tested in order to obtain correlations for the Darcy friction factor. Insight into the magnitude of pressure loss in the proposed geometry of spiral solar receiver for different flow rates is important because of its effect upon the efficiency of the receiver. Although flow in spiral and corrugated geometries has the advantages of compactness and high heat transfer rates, the disadvantage of greater pressure drops makes hydrodynamic studies relevant. [Projekat Ministarstva nauke Republike Srbije, br. III 42006 i br. TR 33015

THE EFFECTS OF SWIRL GENERATOR HAVING WINGS WITH HOLES ON HEAT TRANSFER AND PRESSURE DROP IN TUBE HEAT EXCHANGER

Directory of Open Access Journals (Sweden)

Zeki ARGUNHAN

2006-02-01

Full Text Available This paper examines the effect of turbulance creators on heat transfer and pressure drop used in concentric heat exchanger experimentaly. Heat exchanger has an inlet tube with 60 mm in diameter. The angle of swirl generators wings is 55º with each wing which has single, double, three and four holes. Swirl generators is designed to easily set to heat exchanger entrance. Air is passing through inner tube of heat exhanger as hot fluid and water is passing outer of inner tube as cool fluid.

Video monitoring system for enriched uranium casting furnaces

International Nuclear Information System (INIS)

Turner, P.C.

1978-03-01

A closed-circuit television (CCTV) system was developed to upgrade the remote-viewing capability on two oralloy (highly enriched uranium) casting furnaces in the Y-12 Plant. A silicon vidicon CCTV camera with a remotely controlled lens and infrared filtering was provided to yield a good-quality video presentation of the furnace crucible as the oralloy material is heated from 25 to 1300 0 C. Existing tube-type CCTV monochrome monitors were replaced with solid-state monitors to increase the system reliability

Heat transfer simulation in a furnace for steam reformer. Gas kaishitsu ronai no dennetsu simulation ni kansuru kenkyu

Energy Technology Data Exchange (ETDEWEB)

Kudo, K; Taniguchi, H; Guo, K [Hokkaido Univ., Sapporo (Japan). Faculty of Engineering; Katayama, T; Nagata, T [Tokyo Gas Co. Ltd., Tokyo (Japan)

1991-01-10

This paper discusses the heat transfer analysis in a furnace for LPG reforming to produce gas enriched hydrogen. The three-dimensional combined radiative and convective heat transfer processes in a furnace for LPG reforming is simulated by introducing the radiosity concept into the radiative heat ray method for an accurate radiative heat transfer analysis. Together with an analysis of the chemical reaction in the reactor tubes of the furnace, the heat transfer simulation gives the three-dimensional profile of the combustion gas temperature in the furnace, the tube-surface heat-flux distribution and the composition of the reformed gas. From the results of the analysis, it was clarified that increasing the jet angle of the heating burner raises the gas temperature and the tube surface heat flux near the burner entrance, and that the flame shape is the most important factor for deciding the heat flux distribution of the tube surface because the heat transfer effect by flame radiation is much more than that by convection of the combustion gas. 18 refs., 9 figs., 2 tabs.

IR1 flow tube and In-Pile Test Section Pressure drop test for the 3-Pin Fuel Test Loop

Energy Technology Data Exchange (ETDEWEB)

Lee, H. H.; Park, K. N.; Chi, D. Y.; Sim, B. S.; Park, S. K.; Lee, J. M.; Lee, C. Y.; Kim, H. N

2006-02-15

The in-pile Section (IPS) of 3-pin Fuel Test Loop(FTL) shall be installed in the vertical hole call IR1 of HANARO reactor core. In order to verify the pressure drop and flow rate both the inside region of IPS at the annular region between IPS and IR1 flow tube, a pressure drop was measured by varing the flow rate on both regions. The measured pressure drop in the annular region is 209kpa at 14.9kg/s which meets the limiting condition of operation of 200kpa. The measured pressure drop in side the IPS becomes 260.25kpa which is lower than the designed value of 306.65kpa. As the pressure drop is lower than the design value, it is quite conservative from the safety and operating point of view.

Estimation and optimization of heat transfer and overall presure drop for a shell and tube heat exchanger

Energy Technology Data Exchange (ETDEWEB)

Rao, Bala Bhaskara [Dept. of Mechanical Engineering, SISTAM College, JNTU, Kakinada (India); Raju, V. Ramachandra [Dept. of Mechanical Engineering, JNTU, Kakinada (India); Deepak, B. B V. L. [Dept. of Industrial Design, National Institute of Technology, Rourkela (India)

2017-01-15

Most thermal/chemical industries are equipped with heat exchangers to enhance thermal efficiency. The performance of heat exchangers highly depends on design modifications in the tube side, such as the cross-sectional area, orientation, and baffle cut of the tube. However, these parameters do not exhibit a specific relation to determining the optimum design condition for shell and tube heat exchangers with a maximum heat transfer rate and reduced pressure drops. Accordingly, experimental and numerical simulations are performed for a heat exchanger with varying tube geometries. The heat exchanger considered in this investigation is a single-shell, multiple-pass device. A Generalized regression neural network (GRNN) is applied to generate a relation among the input and output process parameters for the experimental data sets. Then, an Artificial immune system (AIS) is used with GRNN to obtain optimized input parameters. Lastly, results are presented for the developed hybrid GRNN-AIS approach.

Analysis of the effect of tube arrangement and inclination on pressure drop in an intermediate heat exchanger of liquid metal reactor

Energy Technology Data Exchange (ETDEWEB)

ChoiI, Seok Ki; Choi, Il Kon; Nam, Ho Yun; Choi, Jong Hyeun [Korea Atomic Energy Research Institute, Taejeon (Korea)

2002-05-01

An experimental study on the effect of tube arrangement and inclination on the pressure drop in the intermediate heat exchanger is performed. Measurements are made for pressure drop in the triangular and rotated triangular tue arrays whose inclined angles are 30, 45, 60, 75 and 90 degrees. The pitch to tube diameter ratio is 1.6 and the range of Reynolds number based on the free stream velocity and tube diameter is 870-64,000. The experimental results show that the magnitude of dimensionless pressure drop increases with the inclined angle and decreases significantly when the inclined angle is less than 45 degree. The previous correlations are evaluated using the experimental data. The ESDU correlation agrees well with the present data for the triangular arrays. But some discrepancies are observed for the rotated triangular arrays when the inclined angles are 45 and 30 degrees. The Idel'chik correlation generally agrees well with the measured data for the rotated triangular arrays except for inclined angle of 30 degree. The Idel'chik correlation needs modification for the triangular arrays. The modified Idel'chik correlation agrees well with the measure data within 10%. 32 refs., 59 figs., 11 tabs. (Author)

STUDY ON SOFTENING AND DROPPING PROPERTIES OF METALIZED BURDEN INSIDE BLAST FURNACE

Directory of Open Access Journals (Sweden)

Bi-yang Tuo

2014-12-01

Full Text Available The inferences of burden metallization rate on softening-melting dropping properties were investigated through softening-melting dropping test of three kinds of metalized burden pressure drop. The results indicated that the softeningmelting temperature interval of pre-reduction mixed burden is bigger than primeval mixed burden, the melting interval narrow with the rise of metallization rate of ferric burden as well as dropping temperature interval. The average pressure drop, maximum pressure drop and softening-melting dropping properties eigenvalue decrease with the rise of metallization rate of ferric burden. Besides, the dropping temperature of burden reduces with the rise of carbon content of molten iron. The combination high metalized burden and higher carbon content of molten iron is benefit to decreasing thickness of cohesive zone and improve permeability of cohesive zone.

Experimental study of heat transfer and pressure drops for ammonia flowing inside a long tube

International Nuclear Information System (INIS)

Malek, A.; Colin, R.

1985-01-01

This report presents the results of the experimental study of heat transfer coefficients and pressure drops for boiling ammonia in a long tube. The scope of the tests discussed here corresponds to temperatures ranging from 30 to 70 0 C. This touches on various forthcoming applications, including binary cycles of nuclear power plants, as well as miscellaneous energy recovery cycles (heat pumps, geothermal energy, etc.). The results reported here of ammonia evaporators in the temperature range mentionned for two heat exchanger configurations: vertical and horizontal tubes. The correlations expressing the heat transfer coefficients cover the experimental results with a scatter of about +- 0.15% for the three parameters investigated: mass flow rate, heat load, and saturation pressure. As for pressure drops in two-phase flow, an equation expressing the weight of a column of liquid/vapour mixture is satisfactorily compared with the experimental results obtained here. The calculation of this weight is highly important for heat exchanger design, because it helps to predict the recirculation rate in the case of natural circulation. For some cases of evaporators, the calculation of this weight serves to predict the boiling lag in the lower part of the evaporator, which could give rise to low heat transfer coefficient [fr

Influence of structure improvement of guide tubes and bundles in pressurized water reactor (PWR) on drop of control rods

International Nuclear Information System (INIS)

Shen Xiuzhong; Yu Pingan; Yang Guanyue

1996-01-01

In order to alleviate the cross hydraulic load on control rod guide tubes and bundles, some protective sleeves are added to those near the upper plenum outlet nozzles (4 symmetric bundles: 02-26, 03-25, 11-29, 12-28). In a 1/4 scale transparent model of the PWR upper plenum of Qinshan Nuclear Power Station, water was chosen as the fluid and hydraulic experiments with improved control rod guide tubes and bundles were carried out. The results were carefully compared with those of the experiments with unimproved control rod guide tubes and bundles. It is concluded that adding protective sleeves to the control rod guide tubes and bundles near the outlet nozzles will help to lighten the hydraulic load on them and make certain of the free movement and rapid dropping of control rods in the tubes and bundles in emergency by order

Friction pressure drop and heat transfer coefficient of two-phase flow in helically coiled tube once-through steam generator for integrated type marine water reactor

International Nuclear Information System (INIS)

Nariai, Hideki; Kobayashi, Michiyuki; Matsuoka, Takeshi.

1982-01-01

Two-phase friction pressure drop and heat transfer coefficients in a once-through steam generator with helically coiled tubes were investigated with the model test rig of an integrated type marine water reactor. As the dimensions of the heat transfer tubes and the thermal-fluid conditions are almost the same as those of real reactors, the data applicable directly to the real reactor design were obtained. As to the friction pressure drop, modified Kozeki's prediction which is based on the experimental data by Kozeki for coiled tubes, agreed the best with the experimental data. Modified Martinelli-Nelson's prediction which is based on Martinelli-Nelson's multiplier using Ito's equation for single-phase flow in coiled tube, agreed within 30%. The effect of coiled tube on the average heat transfer coefficients at boiling region were small, and the predictions for straight tube could also be applied to coiled tube. Schrock-Grossman's correlation agreed well with the experimental data at the pressures of lower than 3.5 MPa. It was suggested that dryout should be occurred at the quality of greater than 90% within the conditions of this report. (author)

Measurement and correlation of frictional pressure drop of refrigerant-based nanofluid flow boiling inside a horizontal smooth tube

Energy Technology Data Exchange (ETDEWEB)

Peng, Hao; Ding, Guoliang; Jiang, Weiting; Hu, Haitao [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240 (China); Gao, Yifeng [International Copper Association Shanghai Office, 381 Huaihaizhong Road, Shanghai 200020 (China)

2009-11-15

The objective of this paper is to investigate the effect of nanoparticle on the frictional pressure drop characteristics of refrigerant-based nanofluid flow boiling inside a horizontal smooth tube, and to present a correlation for predicting the frictional pressure drop of refrigerant-based nanofluid. R113 refrigerant and CuO nanoparticle were used for preparing refrigerant-based nanofluid. Experimental conditions include mass fluxes from 100 to 200 kg m{sup -2} s{sup -1}, heat fluxes from 3.08 to 6.16 kW m{sup -2}, inlet vapor qualities from 0.2 to 0.7, and mass fractions of nanoparticles from 0 to 0.5 wt%. The experimental results show that the frictional pressured drop of refrigerant-based nanofluid increases with the increase of the mass fraction of nanoparticles, and the maximum enhancement of frictional pressure drop is 20.8% under above conditions. A frictional pressure drop correlation for refrigerant-based nanofluid is proposed, and the predictions agree with 92% of the experimental data within the deviation of {+-}15%. (author)

Coke detection in furnaces tubes by radiographic examination

International Nuclear Information System (INIS)

Santos, I.S. dos

1987-01-01

The coke detection technique by radiographic examinations allows to quantify the coke in furnace coils of Petroleum refineries and petrochemical industries. The paper describes how was determined the radiographic parameters, the wall apparent thickness calculation, the distance source-film, the position of the source and films, the chosen of films and the calculation of exposure time, aiming to obtain high producticity and good quality image. This technique is being used and improved for more than two years with good results. (E.G.) [pt

Modelling and control of a diffusion/LPCVD furnace

Science.gov (United States)

Dewaard, H.; Dekoning, W. L.

1988-12-01

Heat transfer inside a cylindrical resistance diffusion/Low Pressure Chemical Vapor Deposition (LPCVD) furnace is studied with the aim of developing an improved temperature controller. A model of the thermal behavior is derived, which covers the important class of furnaces equipped with semitransparent quartz process tubes. The model takes into account the thermal behavior of the thermocouples. Currently used temperature controllers are shown to be highly inefficient for very large scale integration applications. Based on the model an alternative temperature controller of the LQG (linear quadratic Gaussian) type is proposed which features direct wafer temperature control. Some simulation results are given.

Rod cluster control assemblies and rod cluster control guide tubes: wear and drop time

International Nuclear Information System (INIS)

Zbinden, M.

1997-01-01

The wear of RCCAs and of RCC guide tubes is due to two quite different mechanisms and the remedies to apply for each case might lead to contradictory solutions: - the impact/sliding wear for the seldom moving RCCAs, namely the shutdown RCCAs, under flow-induced vibrations, - the axial sliding wear for the control rods subjected to the stepping movements ordered by the acting load. In this case the hydraulic sticking forces are those which produce an evolution of the surface states that may increase the drop time. The introduction, an historical survey of the encountered difficulties, is followed by short description of the components and then the paper presents contributions of EDF in the R and D field, which take place in two successive multi-annual projects. Lastly, some information is given about the recent evolutions and new problems as well for impact/sliding wear as for drop time under normal or seismic conditions. (author)

Simulation of Working Processes in the Water-Tube Boiler Furnace with the Purpose of Reducing Emissions of Nitrogen Oxides

Directory of Open Access Journals (Sweden)

Redko A.A.

2017-04-01

Full Text Available A significant number of domestic and industrial boilers are in operation in Ukraine. Nitrogen oxides are the most dangerous among all combustion products that pollute the atmosphere, therefore, one should take some measures for decreasing the formation of nitrogen oxides during combustion. The studies were carried out at the boilers of low power (100 kW with a tubular radiator and an open end. The studies in the furnaces of industrial steam boilers having a tubular radiator with a closed end have not been done. The numerical study results of the gaseous fuel combustion processes in the furnace of a DE-10/14 steam water-tube boiler are presented. The fuel-air mixture is formed by premixing the 15% part of the air with a primary burner twist factor n=2.4 and a secondary burner twist factor n=1.6, and an air excess factor αв=10. As a result of the studies, the temperature and velocity distributions of gases in the combustion chamber, the density of heat flows on the screen tubular surfaces, and the concentrations of the combustion components were determined. Flue gas recirculation in the volume of 80-100% is provided, and the reversible movement of combustion products towards the combustion front provides a reduction in the concentration of nitrogen oxides up to 123-125 mg/m3 at the furnace outlet. Disadvantages are the following: the formation of stagnant zones near the end of the secondary radiator. The optimum diameter of the tubular radiator equals to two burners diameters and tubular radiator is located at a distance of one meter from the burner cutoff.

Fluorophotometric determination of uranium: an automated sintering furnace and factors affecting precision

International Nuclear Information System (INIS)

Strain, J.E.

1978-07-01

The fusion furnace consists of four individually controlled, slotted-tube furnaces that automatically dry, sinter and anneal the fluoride or carbonate pellet used in the fluorometric determination of uranium. The furnace operates in air and prepares approximately 90 pellets per hour for fluorometric measurement. The factors that were thought to affect the precision of the method were investigated. The two factors that seem to be the most influential are (1) the manner in which the sample is loaded onto the pellet; and (2) the surface characteristics of the platinum dish in which the pellet is sintered and measured fluorometrically

A numerical investigation of γ-Al2O3-water nanofluids heat transfer and pressure drop in a shell and tube heat exchanger

Directory of Open Access Journals (Sweden)

P. Shahmohammadi

2016-01-01

Full Text Available The effect of γ-Al2O3 nanoparticles on heat transfer rate, baffle spacing and pressure drop in the shell side of small shell and tube heat exchangers was investigated numerically under turbulent regime. γ-Al2O3-water nanofluids and pure water were used in the shell side and the tube side of heat exchangers, respectively. Since the properties of γ-Al2O3-water nanofluids were variable, they were defined using the user define function. The results revealed that heat transfer and pressure drop were increased with mass flow rate as well as baffle numbers. Adding nanoparticles to the based fluid did not have a significant effect on pressure drop in the shell side. The best heat transfer performance of heat exchangers was for γ-Al2O3-water 1 vol.% and higher nanoparticles concentration was not suitable. The suitable baffle spacing was 43.4% of the shell diameter, showing a good agreement with Bell-Delaware method.

Heat transfer, pressure drop and flow patterns during flow boiling of R407C in a horizontal microfin tube

Science.gov (United States)

Rollmann, P.; Spindler, K.; Müller-Steinhagen, H.

2011-08-01

The heat transfer, pressure drop and flow patterns during flow boiling of R407C in a horizontal microfin tube have been investigated. The microfin tube is made of copper with a total fin number of 55 and a helix angle of 15°. The fin height is 0.24 mm and the inner tube diameter at fin root is 8.95 mm. The test tube is 1 m long. It is heated electrically. The experiments have been performed at saturation temperatures between -30°C and +10°C. The mass flux was varied between 25 and 300 kg/m2/s, the heat flux from 20,000 W/m2 down to 1,000 W/m2. The vapour quality was kept constant at 0.1, 0.3, 0.5, 0.7 at the inlet and 0.8, 1.0 at the outlet, respectively. The measured heat transfer coefficient is compared with the correlations of Cavallini et al., Shah as well as Zhang et al. Cavallini's correlation contains seven experimental constants. After fitting these constants to our measured values, the correlation achieves good agreement. The measured pressure drop is compared to the correlations of Pierre, Kuo and Wang as well as Müller-Steinhagen and Heck. The best agreement is achieved with the correlation of Kuo and Wang. Almost all values are calculated within an accuracy of ±30%. The flow regimes were observed. It is shown, that changes in the flow regime affect the heat transfer coefficient significantly.

Parameter optimization through performance analysis of model based control of a batch heat treatment furnace with low NO x radiant tube burner

International Nuclear Information System (INIS)

Tiwari, Manish Kumar; Mukhopadhyay, Achintya; Sanyal, Dipankar

2005-01-01

A model based control structure for heat treating a 0.5% C steel slab in a batch furnace with low NO x radiant tube burner is designed and tested for performance to yield optimal parameter values using the model developed in the companion paper. Combustion is considered in a highly preheated and product gas diluted mode. Controlled combustion with a proposed arrangement for preheating and diluting the air by recirculating the exhaust gas that can be retrofitted with an existing burner yields satisfactory performance and emission characteristics. Finally, the effect of variable property considerations are presented and critically analyzed

Computer simulation of processes in the dead–end furnace

International Nuclear Information System (INIS)

Zavorin, A S; Khaustov, S A; Zaharushkin, Russia N A

2014-01-01

We study turbulent combustion of natural gas in the reverse flame of fire–tube boiler simulated with the ANSYS Fluent 12.1.4 engineering simulation software. Aerodynamic structure and volumetric pressure fields of the flame were calculated. The results are presented in graphical form. The effect of the twist parameter for a drag coefficient of dead–end furnace was estimated. Finite element method was used for simulating the following processes: the combustion of methane in air oxygen, radiant and convective heat transfer, turbulence. Complete geometric model of the dead–end furnace based on boiler drawings was considered

Heat transfer and pressure drop amidst frost layer presence for the full geometry of fin-tube heat exchanger

International Nuclear Information System (INIS)

Kim, Sung Jool; Choi, Ho Jin; Ha, Man Yeong; Kim, Seok Ro; Bang, Seon Wook

2010-01-01

The present study numerically solves the flow and thermal fields in the full geometry of heat exchanger modeling with frost layer presence on the heat exchanger surface. The effects of air inlet velocity, air inlet temperature, frost layer thickness, fin pitch, fin thickness, and heat exchanger shape on the thermo-hydraulic performance of a fin-tube heat exchanger are investigated. Heat transfer rate rises with increasing air inlet velocity and temperature, and decreasing frost layer thickness and fin pitch. Pressure drop rises with increasing air inlet velocity and frost layer thickness, and decreasing fin pitch. The effect of fin thickness on heat transfer and pressure drop is negligible. Based on the present results, we derived the correlations, which express pressure drop and temperature difference between air inlet and outlet as a function of air inlet velocity and temperature, as well as frost layer thickness

Pressure drop and heat transfer in the sodium to air heat exchanger tube banks on advanced sodium-cooled fast reactor

International Nuclear Information System (INIS)

Kang, H.; Eoh, J.; Cha, J.; Kim, S.

2011-01-01

A numerical study was performed to investigate the thermal and hydraulic characteristics and build up design model of the AHX (sodium-to-air heat exchanger) unit of a sodium-cooled fast reactor. Helical-coiled tube banks in the AHX were modeled as porous media and simulated heat and momentum transfer. Two-dimensional flow characteristic appeared at the most region of AHX annulus. Pressure drop and heat transfer coefficient for rectangular, parallelogram and staggered tube banks as the main components of the AHX were evaluated and compared with Zhukauskas empirical correlations. (author)

Application of thermospray flame furnace atomic absorption spectrometry for investigation of silver nanoparticles.

Science.gov (United States)

Sirirat, Natnicha; Tetbuntad, Kornrawee; Siripinyanond, Atitaya

2017-03-01

Thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) was applied to investigate the time-dependent absorption peak profile of various forms of silver. The thermospray flame furnace was set up with a 10-cm-long nickel tube with six holes, each 2.0 mm in diameter, to allow the flame to enter, and this nickel tube acted as a furnace. A sample of 300 μL was introduced into this furnace by use of water as a carrier at a flow rate of 0.5 mL min -1 through the ceramic capillary (0.5-mm inner diameter and 2.0-mm outer diameter), which was inserted into the front hole of the nickel tube. The system was applied to examine atomization behaviors of silver nanoparticles (AgNPs) with particle sizes ranging from 10 to 100 nm. The atomization rate of AgNPs was faster than that of the dissolved silver ion. With increased amount of silver, the decay time observed from the time-dependent absorption peak profile was shortened in the case of dissolved silver ion, but it was increased in the case of AgNPs. With the particle size ranging from 10 to 100 nm, the detection sensitivity was indirectly proportional to the particle size, suggesting that TS-FF-AAS may offer insights into the particle size of AgNPs provided that the concentration of the silver is known. To obtain quantitative information on AgNPs, acid dissolution of the particles was performed before TS-FF-AAS analysis, and recoveries of 80-110% were obtained.

Reports on research achievements in developing high-performance industrial furnaces in fiscal 1998 (Research and development of high-performance industrial furnaces). Volume 1; 1998 nendo koseino kogyoro nado ni kansuru kenkyu kaihatsu seika hokokusho. 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

From the reports on research achievements in developing high-performance industrial furnaces in fiscal 1998, the report volume 1 was prepared as a research achievement report of each working group, detailing fundamental researches, heating furnaces, and heat treatment furnaces. The fundamental researches have researched combustion evaluating technology, characteristics of the area in the vicinity of a combustor, characteristics of combustion of high-temperature air, heating characteristics of a furnace to investigate effect of local heat absorption, and combustion evaluation. For the heating furnaces, the following subjects were studied: development of an in-furnace combustion model, summary of an experiment for evaluating high-temperature air combustion, furnace height relative to combustion heat transfer characteristics, heat loss minimizing technology, combustion heat transfer characteristics of liquid fuels, optimal operation of the high-temperature air combustion, basic control in heating control, and steel piece heating control. Studies were performed for the heat treatment furnaces on the case of a direct firing furnace in evaluating the heat transfer characteristics, the case of a radiant tube furnace, application of thermal fluid simulation technology, furnace averaging technology, soot reducing technology, control technology, and trial design on a high-performance heat treatment furnace. (NEDO)

Two-phase heat transfer and pressure drop of LNG during saturated flow boiling in a horizontal tube

Science.gov (United States)

Chen, Dongsheng; Shi, Yumei

2013-12-01

Two-phase heat transfer and pressure drop of LNG (liquefied natural gas) have been measured in a horizontal smooth tube with an inner diameter of 8 mm. The experiments were conducted at inlet pressures from 0.3 to 0.7 MPa with a heat flux of 8-36 kW m-2, and mass flux of 49.2-201.8 kg m-2 s-1. The effect of vapor quality, inlet pressure, heat flux and mass flux on the heat transfer characteristic are discussed. The comparisons of the experimental data with the predicted value by existing correlations are analyzed. Zou et al. (2010) correlation shows the best accuracy with 24.1% RMS deviation among them. Moreover four frictional pressure drop methods are also chosen to compare with the experimental database.

Pressure drop in T's in concentric ducts

International Nuclear Information System (INIS)

Shock, R.A.W.

1983-02-01

A set of experiments has been carried out to measure the pressure drop characteristics of single-phase flow in dividing and joining right-angled T's in a concentric ducting system. These have been compared with measured pressure drops in a simple round tube system. In most tests with the concentric system the number of velocity heads lost is either similar to, or more than, the value for the round tubes. (author)

Thermo hydraulics of a steam boiler forced circulation

International Nuclear Information System (INIS)

Tucakovic, Dragan; Zivanovic, Titoslav; Stevanovic, Vladimir

2006-01-01

In order to minimize the dryout at the steam boiler furnace in the Thermal Power Plant Kolubara B, designed are inner rifled wall tubes. This type of tubes, with many spiral grooves cut into the bore, prevents film boiling and enables the nucleate boiling be still maintained under the condition of vapour quality being app. 1. To verify the choice of the rifled tubes instead of the cheaper, smooth tubes type being justified, analyzed is the change of the actual and critical vapour quality with the furnace height, under uniform and non-uniform heat flu through evaporator walls. Furthermore, made are hydraulic calculations for various steam boiler loads, in case of both rifled and smooth tubes types, with the purpose to check the rifles influence to pressure drop increase in comparison with the smooth tubes. Also, checked is the selection of the circulation pump. Key words: evaporator, forced circulation, rifled tubes, critical vapour quality, pressure drop

Coal char combustion under a CO{sub 2}-rich atmosphere: Implications for pulverized coal injection in a blast furnace

Energy Technology Data Exchange (ETDEWEB)

Borrego, A.G.; Casal, M.D. [Instituto Nacional del Carbon, CSIC. P.O. Box 73, 33080 Oviedo (Spain); Osorio, E.; Vilela, A.C.F. [Laboratorio de Siderurgia, DEMET/PPGEM - Universidade Federal do Rio Grande do Sul. P.O. Box 15021, 91501-970 Porto Alegre (Brazil)

2008-11-15

Pulverized coal injection (PCI) is employed in blast furnace tuyeres attempting to maximize the injection rate without increasing the amount of unburned char inside the stack of the blast furnace. When coal is injected with air through the injection lance, the resolidified char will burn in an atmosphere with a progressively lower oxygen content and higher CO{sub 2} concentration. In this study an experimental approach was followed to separate the combustion process into two distinct devolatilization and combustion steps. Initially coal was injected into a drop tube furnace (DTF) operating at 1300 C in an atmosphere with a low oxygen concentration to ensure the combustion of volatiles and prevent the formation of soot. Then the char was refired into the DTF at the same temperature under two different atmospheres O{sub 2}/N{sub 2} (typical combustion) and O{sub 2}/CO{sub 2} (oxy-combustion) with the same oxygen concentration. Coal injection was also performed under a higher oxygen concentration in atmospheres typical for both combustion and oxy-combustion. The fuels tested comprised a petroleum coke and coals currently used for PCI injection ranging from high volatile to low volatile bituminous rank. Thermogravimetric analyses and microscopy techniques were used to establish the reactivity and appearance of the chars. Overall similar burnouts were achieved with N{sub 2} and CO{sub 2} for similar oxygen concentrations and therefore no loss in burnout should be expected as a result of enrichment in CO{sub 2} in the blast furnace gas. The advantage of increasing the amount of oxygen in a reacting atmosphere during burnout was found to be greater, the higher the rank of the coal. (author)

Dental Porcelain Furnaces: Test and Evaluation.

Science.gov (United States)

1988-01-01

D Q)L a ) a) C ) C C C C c *. . 3a)0. >4 a)->4 >4 -, Z 0 -a-’- 4-% a) ( nca )m m nU Cs C ) (3 ) 11) a) a) a3) Q) a) W) a2) C C~~ >4 L > > >1 >1 4 > 4...Fig. 1) is a computerized programmable porcelain furnace with 45 open programs. This unit has a large detachable cathode -ray tube (CRT) screen which

Solidification of refractory materials processed in the ultra high vacuum drop tube at the CEREM-Grenoble

International Nuclear Information System (INIS)

Vinet, B.; Cini, E.; Tournier, S.; Cortella, L.

1994-01-01

Undercooling experiments have been performed on refractory materials by processing in a high drop-tube. Emphasis is put on general aspects of surface and bulk microstructures of solidified droplets, including pure metals (W, Re, Ta, Mo, Nb, Ir, Zr) and alloys (W-Re, Mo-Re, Ta-Zr). It is shown that recrystallization often causes polycrystallinity. Moreover, the microstructure is closely related to undercooling amount prior solidification. The effect of secondary cooling on microstructure can also be studied by quenching the samples in solid tin at the end of free-fall. (authors). 20 refs., 11 figs

Numerical analysis on the condensation heat transfer and pressure drop characteristics of the horizontal tubes of modular shell and tube-bundle heat exchanger

International Nuclear Information System (INIS)

Ko, Seung Hwan; Park, Hyung Gyu; Kim, Charn Jung; Park, Byung Kyu

2001-01-01

A numerical analysis of the heat and mass transfer and pressure drop characteristics in modular shell and tube bundle heat exchanger was carried out. Finite concept method based on FVM and κ-ε turbulent model were used for this analysis. Condensation heat transfer enhanced total heat transfer rate 4∼8% higher than that of dry heat exchanger. With increasing humid air inlet velocity, temperature and relative humidity, and with decreasing heat exchanger aspect ratio and cooling water velocity, total heat and mass transfer rate could be increased. Cooling water inlet velocity had little effect on total heat transfer

Experimental investigation and correlation of two-phase frictional pressure drop of R410A-oil mixture flow boiling in a 5 mm microfin tube

Energy Technology Data Exchange (ETDEWEB)

Ding, Guoliang; Hu, Haitao; Huang, Xiangchao [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Deng, Bin [Institute of Heat Transfer Technology, Golden Dragon Precise Copper Tube Group Inc., Shanghai 200135 (China); Gao, Yifeng [International Copper Association, Shanghai Office, Shanghai 200020 (China)

2009-01-15

This study presents experimental two-phase frictional data for R410A-oil mixture flow boiling in an internal spiral grooved microfin tube with outside diameter of 5 mm. Experimental parameters include the evaporation temperature of 5 C, the mass flux from 200 to 400 kg m{sup -2} s{sup -1}, the heat flux from 7.46 to 14.92 kW m{sup -2}, the inlet vapor quality from 0.1 to 0.8, and nominal oil concentration from 0 to 5%. The test results show that the frictional pressure drop of R410A initially increases with vapor quality and then decreases, presenting a local maximum in the vapor quality range between 0.7 and 0.8; the frictional pressure drop of R410A-oil mixture increases with the mass flux, the presence of oil enhances two-phase frictional pressure drop, and the effect of oil on frictional pressure drop is more evident at higher vapor qualities where the local oil concentrations are higher. The enhanced factor is always larger than unity and increases with nominal oil concentration at a given vapor quality. The range of the enhanced factor is about 1.0-2.2 at present test conditions. A new correlation to predict the local frictional pressure drop of R410A-oil mixture flow boiling inside the internal spiral grooved microfin tube is developed based on local properties of refrigerant-oil mixture, and the measured local frictional pressure drop is well correlated with the empirical equation proposed by the authors. (author)

Two-phase flow boiling pressure drop in small channels

International Nuclear Information System (INIS)

Sardeshpande, Madhavi V.; Shastri, Parikshit; Ranade, Vivek V.

2016-01-01

Highlights: • Study of typical 19 mm steam generator tube has been undertaken in detail. • Study of two phase flow boiling pressure drop, flow instability and identification of flow regimes using pressure fluctuations is the main focus of present work. • Effect of heat and mass flux on pressure drop and void fraction was studied. • Flow regimes identified from pressure fluctuations data using FFT plots. • Homogeneous model predicted pressure drop well in agreement. - Abstract: Two-phase flow boiling in small channels finds a variety of applications in power and process industries. Heat transfer, boiling flow regimes, flow instabilities, pressure drop and dry out are some of the key issues related to two-phase flow boiling in channels. In this work, the focus is on pressure drop in two-phase flow boiling in tubes of 19 mm diameter. These tubes are typically used in steam generators. Relatively limited experimental database is available on 19 mm ID tube. Therefore, in the present work, the experimental set-up is designed for studying flow boiling in 19 mm ID tube in such a way that any of the different flow regimes occurring in a steam generator tube (from pre-heating of sub-cooled water to dry-out) can be investigated by varying inlet conditions. The reported results cover a reasonable range of heat and mass flux conditions such as 9–27 kW/m 2 and 2.9–5.9 kg/m 2 s respectively. In this paper, various existing correlations are assessed against experimental data for the pressure drop in a single, vertical channel during flow boiling of water at near-atmospheric pressure. A special feature of these experiments is that time-dependent pressures are measured at four locations along the channel. The steady-state pressure drop is estimated and the identification of boiling flow regimes is done with transient characteristics using time series analysis. Experimental data and corresponding results are compared with the reported correlations. The results will be

Heat transfer intensification within tube recuperator by inserting secondary emitters inside air channels

International Nuclear Information System (INIS)

Sandor, P.; Soroka, B.; Kudryavtsev, V.; Zgurskyy, V.

2009-01-01

The research program was stipulated by reduction the service life of the tube recuperators of reheating furnaces at DUNAFERR metallurgical works in Dunaujvaros (Hungary) while replacement the natural gas by coke - oven gas as a furnace fuel took place and air preheating temperature was increased. The tests procedure consists in comparison of temperature and pressure distributions by air flows preheating under air moving inside the tube loops. Advantages of new recuperator design compared to ordinary one have been proven by validation of concept for adequacy to the testing results. The first tests have demonstrated enhancement of local specific and total heat fluxes transferred from flue gases to air flow within the MD tube loops in comparison with those for BD loops by 25 to 45% - dependence on temperature level within the heating (furnace) chamber and on preheated air flow rate. (author)

A new method to calculate pressure drop and shell-side heat transfer coefficient in a shell-and-tube heat exchanger

International Nuclear Information System (INIS)

Baptista Filho, B.D.; Konuk, A.A.

1981-01-01

A new method to calculate pressure drop (Δp) and shell-side heat transfer coefficient (h sub(c)) in a shell-and-tube heat exchanger with segmental baffles is presented. The method is based on the solution of the equations of conservation of mass and momentum between two baffles. The calculated distributions of pressure and velocities given respectively, Δp and h sub(c). The values of Δp and h sub(c) are correlated for a given geometry whit the shell side fluid properties and flow rate. The calculated and experimental results agree very well for a U-Tube heat exchanger. (Author) [pt

Recycling of rubber tires in electric arc furnace steelmaking: simultaneous combustion of metallurgical coke and rubber tyres blends

Energy Technology Data Exchange (ETDEWEB)

Magdalena Zaharia; Veena Sahajwalla; Byong-Chul Kim; Rita Khanna; N. Saha-Chaudhury; Paul O' Kane; Jonathan Dicker; Catherine Skidmore; David Knights [University of New South Wales, Sydney, NSW (Australia). School of Materials Science and Engineering

2009-05-15

The present study investigates the effect of addition of waste rubber tires on the combustion behavior of its blends with coke for carbon injection in electric arc furnace steelmaking. Waste rubber tires were mixed in different proportions with metallurgical coke (MC) (10:90, 20:80, 30:70) for combustion and pyrolysis at 1473 K in a drop tube furnace (DTF) and thermogravimetric analyzer (TGA), respectively. Under experimental conditions most of the rubber blends indicated higher combustion efficiencies compared to those of the constituent coke. In the early stage of combustion the weight loss rate of the blends is much faster compared to that of the raw coke due to the higher volatile yield of rubber. The presence of rubber in the blends may have had an impact upon the structure during the release and combustion of their high volatile matter (VM) and hence increased char burnout. Measurements of micropore surface area and bulk density of the chars collected after combustion support the higher combustion efficiency of the blends in comparison to coke alone. The surface morphology of the 30% rubber blend revealed pores in the residual char that might be attributed to volatile evolution during high temperature reaction in oxygen atmosphere. Physical properties and VM appear to have a major effect upon the measured combustion efficiency of rubber blends. The study demonstrates that waste rubber tires can be successfully co-injected with metallurgical coke in electric arc furnace steelmaking process to provide additional energy from combustion. 44 refs., 11 figs., 2 tabs.

Experimental sizing and assessment of two-phase pressure drop correlations for a capillary tube with transcritical and subcritical carbon dioxide flow

International Nuclear Information System (INIS)

Trinchieri, R; Boccardi, G; Calabrese, N; Zummo, G; Celata, G P

2014-01-01

In the last years, CO 2 was proposed as an alternative refrigerant for different refrigeration applications (automotive air conditioning, heat pumps, refrigerant plants, etc.) In the case of low power refrigeration applications, as a household refrigerator, the use of too expensive components is not economically sustainable; therefore, even if the use of CO 2 as the refrigerant is desired, it is preferable to use conventional components as much as possible. For these reasons, the capillary tube is frequently proposed as expansion system. Then, it is necessary to characterize the capillary in terms of knowledge of the evolving mass flow rate and the associate pressure drop under all possible operative conditions. For this aim, an experimental campaign has been carried out on the ENEA test loop 'CADORE' to measure the performance of three capillary tubes having same inner diameter (0.55 mm) but different lengths (4, 6 and 8 meters). The test range of inlet pressure is between about 60 and 110 bar, whereas external temperatures are between about 20 to 42 °C. The two-phase pressure drop through the capillary tube is detected and experimental values are compared with the predictions obtained with the more widely used correlations available in the literature. Correlations have been tested over a wide range of variation of inlet flow conditions, as a function of different inlet parameters.

Injection of heavy fuel oil into the blast furnace

Energy Technology Data Exchange (ETDEWEB)

Paloposki, T. [Helsinki Univ. of Technology, Otaniemi (Finland); Hakala, J.; Mannila, P.; Laukkanen, J. [Oulu Univ. (Finland)

1996-12-31

This study deals with the injection and combustion of heavy fuel oil in blast furnaces. The injection of the oil was studied experimentally in a small-scale test rig. The combustion of the oil was analysed with a commercial computer program for flow and combustion simulations. Results from computer simulations show that the combustion of the oil can be improved by decreasing the size of the oil drops and by enhancing the mixing between the oil drops and the hot blast. The devolatilization rate of the oil mainly depends on the size of the oil drops. The combustion rate of the volatiles mainly depends on the effectiveness of turbulent mixing with combustion air. Methods to decrease the size of the oil drops were sought in the experimental part of the study. Experimental results show that the size of the oil drops increases with increasing mass flow rate of the oil and decreases with increasing velocity of the hot blast. Methods to improve the mixing between the oil drops and the hot blast are suggested but have not yet been experimentally tested. (author) (4 refs.)

Injection of heavy fuel oil into the blast furnace

Energy Technology Data Exchange (ETDEWEB)

Paloposki, T [Helsinki Univ. of Technology, Otaniemi (Finland); Hakala, J; Mannila, P; Laukkanen, J [Oulu Univ. (Finland)

1997-12-31

This study deals with the injection and combustion of heavy fuel oil in blast furnaces. The injection of the oil was studied experimentally in a small-scale test rig. The combustion of the oil was analysed with a commercial computer program for flow and combustion simulations. Results from computer simulations show that the combustion of the oil can be improved by decreasing the size of the oil drops and by enhancing the mixing between the oil drops and the hot blast. The devolatilization rate of the oil mainly depends on the size of the oil drops. The combustion rate of the volatiles mainly depends on the effectiveness of turbulent mixing with combustion air. Methods to decrease the size of the oil drops were sought in the experimental part of the study. Experimental results show that the size of the oil drops increases with increasing mass flow rate of the oil and decreases with increasing velocity of the hot blast. Methods to improve the mixing between the oil drops and the hot blast are suggested but have not yet been experimentally tested. (author) (4 refs.)

Modern State and Efficiency Analysis of Heat Recovery in Fuel Furnaces Using High Temperature Recuperators. Part 2

Directory of Open Access Journals (Sweden)

B. S. Soroka

2013-01-01

Full Text Available The paper analyzes various factors that affect upon heat transfer in high temperature recuperators, namely: heat transfer enhancement, heat exchange surface increase and rise of temperature head between primary and secondary heat transfer fluids. Comparison of experimental data with the results of mathematical and computational fluid dynamics (CFD modeling has been performed in the paper. The paper considers some new designs of high temperature heat recovery plants: tube recuperator equipped with internal inserts – secondary emitters inside tubes for metallurgical furnaces and high-efficient two-way radiative recuperators for machinery engineering furnaces.  Advantages of new recuperators in comparison with existing analogues have been estimated in the paper. These advantages are:  provision of additional fuel saving due to increase of preheating temperature of the combustion air and improvement of design stability by decrease of tube wall temperature.

Remote maintenance techniques in the furnace cell of a high level waste vitrification plant

International Nuclear Information System (INIS)

Selig, M.

1983-01-01

Remote controlled maintenance and changing techniques for the furnace of a vitrification plant for radioactive waste was developed and tested on a 1:1 model. The model was fitted out with imitation main components, remote control equipment, lead-ins and the complete tubing so that the trials could be carried out in a manner replicating as closely as possible the situation found under operating conditions. The development of remote-handled tube cable connectors, tube cable jumpers and plugs and sockets was an important aspect of the developmental programme. (orig.) [de

Technological indicators of operation of the rotating-hearth furnace in conditions of discontinued production

Directory of Open Access Journals (Sweden)

Lazić, L.

2008-04-01

Full Text Available Quality heating of the steel charge to be rolled into seamless tubes in the rotating-hearth furnace requires continuous operation of the pilger mill. Interruption of the charging schedule leads to impaired charge heating process. Prolonged heating time causes a rise in the charge temperature above the limit values, and that in turn brings to a larger quantity of scale formed on the charge surface. Final result is loss of metal and overheating of the charge accompanied by increased fuel consumption and lower furnace productivity.

The development of crack measurement system using the direct current potential drop method for use in the hot cell

International Nuclear Information System (INIS)

Kim, Do-Sik; Ahn, Sang-Bok; Lee, Key-Soon; Kim, Yong-Suk; Kwon, Sang-Chul

1999-01-01

The crack length measurement system using the direct current potential drop (DCPD) method was developed for the detection of crack growth initiation and subsequent crack growth. The experimental precautions and data processing procedure required for its application were also described find discussed. The system presented herein was specially built for use in fracture toughness testing of unirradiated or irradiated pressure tube materials from nuclear reactor. The application of this system for fracture toughness determination was illustrated from the test of curved compact tension specimens removed from CANDU reactor pressure tubes. The crack extension was monitored using the DCPD method. It is found that the changes of the potential drop and the changes of the crack length have a linear relationship. The final crack front was marked by heat-tinting after the test and the specimen broken open for determination of the initial and final physical crack length. The physical crack lengths, obtained by the 9-point average method described in ASTM E1737-96 on heat-tinted fracture surface, were used to calibrate the DCPD method for each test on an individual basis by matching the change in voltage to the crack extension. It is found that this system can be recommended for determination of the J-integral resistance (J-R) curve of unirradiated or irradiation materials in the hot cell, especially when testing at elevated temperature and in the environment chamber or furnace. (author)

Pressure drop and heat transfer of a mercury single-phase flow and an air-mercury two-phase flow in a helical tube under a strong magnetic field

International Nuclear Information System (INIS)

Takahashi, Minoru; Momozaki, Yoichi

2000-01-01

For the reduction of a large magneto-hydrodynamic (MHD) pressure drop of a liquid metal single-phase flow, a liquid metal two-phase flow cooling system has been proposed. As a fundamental study, MHD pressure drops and heat transfer characteristics of a mercury single-phase flow and an air-mercury two-phase flow were experimentally investigated. A strong transverse magnetic field relevant to the fusion reactor conditions was applied to the mercury single-phase flow and the air-mercury two-phase flow in a helically coiled tube that was inserted in the vertical bore of a solenoidal superconducting magnet. It was found that MHD pressure drops of a mercury single-phase flow in the helically coiled tube were nearly equal to those in a straight tube. The Nusselt number at an outside wall was higher than that at an inside wall both in the mercury single-phase flow in the absence and presence of a magnetic field. The Nusselt number of the mercury single-phase flow decreased, increased and again decreased with an increase in the magnetic flux density. MHD pressure drops did not decrease appreciably by injecting air into a mercury flow and changing the mercury flow into the air-mercury two-phase flow. Remarkable heat transfer enhancement did not appear by the air injection. The injection of air into the mercury flow enhanced heat transfer in the ranges of high mercury flow rate and low magnetic flux density, possibly due to the agitation effect of air bubbles. The air injection deteriorated heat transfer in the range of low mercury flow rates possibly because of the occupation of air near heating wall

Modeling and control of diffusion and low-pressure chemical vapor deposition furnaces

Science.gov (United States)

De Waard, H.; De Koning, W. L.

1990-03-01

In this paper a study is made of the heat transfer inside cylindrical resistance diffusion and low-pressure chemical vapor deposition furnaces, aimed at developing an improved temperature controller. A model of the thermal behavior is derived which also covers the important class of furnaces equipped with semitransparent quartz process tubes. The model takes into account the thermal behavior of the thermocouples. It is shown that currently used temperature controllers are highly inefficient for very large scale integration applications. Based on the model an alternative temperature controller of the linear-quadratic-Gaussian type is proposed which features direct wafer temperature control. Some simulation results are given.

Pendent_Drop: An ImageJ Plugin to Measure the Surface Tension from an Image of a Pendent Drop

Directory of Open Access Journals (Sweden)

Adrian Daerr

2016-01-01

Full Text Available The pendent drop method for surface tension measurement consists in analysing the shape of an axisymmetric drop hanging from a capillary tube. This software is an add-on for the public domain image processing software ImageJ which matches a theoretical profile to the contour of a pendent drop, either interactively or by automatically minimising the mismatch. It provides an estimate of the surface tension, drop volume and surface area from the best matching parameters. It can be used in a headless setup. It is hosted on http://fiji.sc/List_of_update_sites with the source code on https://github.com/adaerr/pendent-drop

Preparation of metallic uranium tubes; Elaboration des tubes d'uranium metallique

Energy Technology Data Exchange (ETDEWEB)

Lerouge, G; Decours, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The production furnace is an induction heated vacuum furnace having a capacity at the moment of 250 kg. Previously the crucible was heated by the inductor, the mould being outside the inductor. The tubes thus produced contained cavities, the alloy structure was fine; this was cold-mould casting, At the moment the top of the moulds are pre-heated, this is the so called hot-mould casting. This method has the advantage of eliminating the cavities but leads to a less fine microstructure. The alloy used for the 18 x 40 mm and 23 x 43 mm tubes is U-Mo (1.1 per cent). Since the moulds are now heated at the top, the solidification of the metal is very slow in this zone leading to a pronounced {gamma} grain, whereas towards the base the faster cooling leads to a smaller {gamma} grain. The {gamma} structure depends essentially on the solidification rate and on the time spent in this zone. In order to obtain a fine and homogeneous grain along the whole length of the tube, a controlled cooling treatment is effected. It consists in heating the uranium tubes in the {gamma} place and then in cooling them at a rate of between 20 and 50 deg C/mm down to 400 deg C. The 77 x 95 mm and 54 x 70 mm annular elements are at the moment being produced for research purposes. Their preparation is similar to that of 18 x 40 mm and 23 x 43 mm elements. The 77 x 95 mm tubes are at the moment made from U-Cr alloy (0.1 per cent); because of their size, their preparation is carried out in 600 mm diameter furnaces. (authors) [French] Le four d'elaboration est un four sous vide chaufffe par induction, dont la capacite actuelle est de 250 kg. Anterieurement le creuset seul etait chauffe par l'inducteur, les moules etaient hors de l'inducteur. Les tubes obtenus presentaient des cavites, la structure de l'alliage etait fine, c'etait la coulee en moules froids. Actuellement on prechauffe le haut des moules, c'est la coulee dite en moules chauds. Cette facon de faire a l'avantage de supprimer les cavites

Speciation and determination of ultra trace amounts of chromium by solidified floating organic drop microextraction (SFODME) and graphite furnace atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Moghadam, Masoud Rohani [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of); Dadfarnia, Shayessteh, E-mail: sdadfarnia@yazduni.ac.ir [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of); Haji Shabani, Ali Mohammad [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of)

2011-02-15

Solidified floating organic drop microextraction (SFODME) method in combination with graphite furnace atomic absorption spectrometry (GFAAS) has been used for the determination of chromium species in water and urine samples. 1-undecanol containing 2-thenoyltrifluoroacetone (TTA) was used as a selective chelating agent for the extraction of Cr(III). The total Cr was determined after the reduction of Cr(VI) to Cr(III) with hydroxylamine. The concentration of Cr(VI) was determined from the difference between the concentration of total chromium and the Cr(III). Several variables such as the sample pH, concentration of TTA, salt concentration, extraction time and the sample volume were investigated in detail. Under the optimum conditions, the limit of detection of the proposed method was 0.006 {mu}g l{sup -1} for Cr(III) and the relative standard deviation for six replicate determinations at 0.1 {mu}g l{sup -1} Cr(III) was 5.1%. The proposed method was successfully applied for the determination of chromium species in tap water, well water, mineral water, and urine samples.

Fire-tube boiler optimization criteria and efficiency indicators rational values defining

Science.gov (United States)

Batrakov, P. A.; Mikhailov, A. G.; Ignatov, V. Yu

2018-01-01

Technical and economic calculations problems solving with the aim of identifying the opportunity to recommend the project for industrial implementation are represented in the paper. One of the main determining factors impacting boiler energy efficiency is the exhaust gases temperature, as well as the furnace volume thermal stress. Fire-tube boilers with different types of furnaces are considered in the study. The fullest analysis of the boiler performance thermal and technical indicators for the following engineering problem: Q=idem, M=idem and evaluation according to η, B is presented. The furnace with the finned ellipse profile application results in the fuel consumption decrease due to a more efficient heat exchange surface of the furnace compared to other examined ones.

Combustion behaviour of ultra clean coal obtained by chemical demineralisation

Energy Technology Data Exchange (ETDEWEB)

F. Rubiera; A. Arenillas; B. Arias; J.J. Pis; I. Suarez-Ruiz; K.M. Steel; J.W. Patrick [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

2003-10-01

The increasing environmental concern caused by the use of fossil fuels and the concomitant need for improved combustion efficiency is leading to the development of new coal cleaning and utilisation processes. However, the benefits achieved by the removal of most mineral matter from coal either by physical or chemical methods can be annulled if poor coal combustibility characteristics are attained. In this work a high volatile bituminous coal with 6% ash content was subjected to chemical demineralisation via hydrofluoric and nitric acid leaching, the ash content of the clean coal was reduced to 0.3%. The original and treated coals were devolatilised in a drop tube furnace and the structure and morphology of the resultant chars was analysed by optical and scanning electron microscopies. The reactivity characteristics of the chars were studied by isothermal combustion tests in air at different temperatures in a thermogravimetric system. Comparison of the combustion behaviour and pollutant emissions of both coals was conducted in a drop tube furnace operating at 1000{sup o}C. The results of this work indicate that the char obtained from the chemically treated coal presents very different structure, morphology and reactivity behaviour than the char from the original coal. The changes induced by the chemical treatment increased the combustion efficiency determined in the drop tube furnace, in fact higher burnout levels were obtained for the demineralised coal.

Heat treatment furnace

Science.gov (United States)

Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T

2014-10-21

A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.

Preparation of metallic uranium tubes; Elaboration des tubes d'uranium metallique

Energy Technology Data Exchange (ETDEWEB)

Lerouge, G.; Decours, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The production furnace is an induction heated vacuum furnace having a capacity at the moment of 250 kg. Previously the crucible was heated by the inductor, the mould being outside the inductor. The tubes thus produced contained cavities, the alloy structure was fine; this was cold-mould casting, At the moment the top of the moulds are pre-heated, this is the so called hot-mould casting. This method has the advantage of eliminating the cavities but leads to a less fine microstructure. The alloy used for the 18 x 40 mm and 23 x 43 mm tubes is U-Mo (1.1 per cent). Since the moulds are now heated at the top, the solidification of the metal is very slow in this zone leading to a pronounced {gamma} grain, whereas towards the base the faster cooling leads to a smaller {gamma} grain. The {gamma} structure depends essentially on the solidification rate and on the time spent in this zone. In order to obtain a fine and homogeneous grain along the whole length of the tube, a controlled cooling treatment is effected. It consists in heating the uranium tubes in the {gamma} place and then in cooling them at a rate of between 20 and 50 deg C/mm down to 400 deg C. The 77 x 95 mm and 54 x 70 mm annular elements are at the moment being produced for research purposes. Their preparation is similar to that of 18 x 40 mm and 23 x 43 mm elements. The 77 x 95 mm tubes are at the moment made from U-Cr alloy (0.1 per cent); because of their size, their preparation is carried out in 600 mm diameter furnaces. (authors) [French] Le four d'elaboration est un four sous vide chaufffe par induction, dont la capacite actuelle est de 250 kg. Anterieurement le creuset seul etait chauffe par l'inducteur, les moules etaient hors de l'inducteur. Les tubes obtenus presentaient des cavites, la structure de l'alliage etait fine, c'etait la coulee en moules froids. Actuellement on prechauffe le haut des moules, c'est la coulee dite en moules chauds. Cette facon de faire a l

The new Drop Tower catapult system

Science.gov (United States)

von Kampen, Peter; Kaczmarczik, Ulrich; Rath, Hans J.

2006-07-01

The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of the "Drop Tower" began. Since then, the eye-catching tower with a height of 146 m and its characteristic glass roof has become the emblem of the technology centre in Bremen. The Drop Tower Bremen provides a facility for experiments under conditions of weightlessness. Items are considered weightless, when they are in "free fall", i.e. moving without propulsion within the gravity field of the earth. The height of the tower limits the simple "free fall" experiment period to max. 4.74 s. With the inauguration of the catapult system in December 2004, the ZARM is entering a new dimension. This world novelty will meet scientists' demands of extending the experiment period up to 9.5 s. Since turning the first sod on May 3rd, 1988, the later installation of the catapult system has been taken into account by building the necessary chamber under the tower. The catapult system is located in a chamber 10 m below the base of the tower. This chamber is almost completely occupied by 12 huge pressure tanks. These tanks are placed around the elongation of the vacuum chamber of the drop tube. In its centre there is the pneumatic piston that accelerates the drop capsule by the pressure difference between the vacuum inside the drop tube and the pressure inside the tanks. The acceleration level is adjusted by means of a servo hydraulic breaking system controlling the piston velocity. After only a quarter of a second the drop capsule achieves its lift-off speed of 175 km/h. With this exact speed, the capsule will rise up to the top of the tower and afterwards fall down again into the deceleration unit which has been moved under the drop tube in the meantime. The scientific advantages of the doubled experiment time are obvious: during almost 10 s of high

High Temperature Transparent Furnace Development

Science.gov (United States)

Bates, Stephen C.

1997-01-01

This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

[The electric furnace of Henri Moissan at one hundred years: connection with the electric furnace, the solar furnace, the plasma furnace?].

Science.gov (United States)

Royère, C

1999-03-01

The trace of Henri Moissan's pioneer work 100 years ago is clearly evidenced by an overview of achievements in high temperature devices; 1987: "Le four électrique" by Henri Moissan; 1948-1952: "High temperature heating in a cavity rotary kiln using focusing of solar radiation" by Félix Trombe; 1962: "The cavity rotary kiln using focused solar radiation jointly with a plasma gun" by Marc Foëx; 1970: "The rotary kiln with two plasma guns and arc transfer" by Marc Foëx; 1984: "The plasma furnace" by Electricité de France (EDF) at Renardières; 1997: "The plasma furnace" by the Atomic Energy Center (CEA) at Cadarache, the VULCANO program. The first part of this contribution is devoted to Henri Moissan. Re-reading his early book on the electric furnace, especially the first chapter and the sections on silica, carbon vapor and experiments performed in casting molten metal--the conclusions are outstanding--provides modern readers with an amazing insight into future developments. The last two parts are devoted to Félix Trombe and Marc Foëx, tracing the evolution of high temperature cavity processus leading to the solar furnace and the present day plasma furnace at the CEA. Focus is placed on research conducted by the French National Center for Scientific Research (CNRS) with the solar and plasma furnaces at Odeillo. The relationships with Henri Moissan's early work are amazing, offering a well deserved homage to this pioneer researcher.

Numerical simulation of altitude impact on pulverized coal combustion

Energy Technology Data Exchange (ETDEWEB)

Pei, Xiaohui; He, Boshu; Ling, Ling; Wang, Lei [Beijing Jiaotong Univ., Beijing (China). Inst. of Mechanical, Electronic and Control Engineering

2013-07-01

A drop-tube Furnace simulation model has been developed to investigate the pulverized coal combustion characteristics under different altitudes using the commercially available software Fluent. The altitude conditions of 0, 500, 1,000, 1,500 m have been discussed. The results included the fields of temperature, pressure, velocity, the coal burnout, CO burnout and NO emission in the tube furnace. The variation of these parameters with altitude has been analyzed. The coal combustion characteristics were affected by the altitude. The time and space for coal burnout should be increased with the rise of altitude. The valuable results could be referenced in the design of coal- fired furnaces for the high altitude areas.

Oil injection into the blast furnace

Energy Technology Data Exchange (ETDEWEB)

Dongsheng Liao; Mannila, P.; Haerkki, J.

1997-12-31

Fuel injection techniques have been extensively used in the commercial blast furnaces, a number of publications concerning the fuels injection have been reported. This present report only summarizes the study achievements of oil injection due to the research need the of authors, it includes the following parts: First, the background and the reasons reducing coke rate of oil injection are analyzed. Reducing coke rate and decreasing the ironmaking costs are the main deriving forces, the contents of C, H and ash are direct reasons reducing coke rate. It was also found that oil injection had great effects on the state of blast furnace, it made operation stable, center gas flow develop fully, pressure drop increase, descent speed of burden materials decrease and generation of thermal stagnation phenomena, the quality of iron was improved. Based on these effects, as an ideal mean, oil injection was often used to adjust the state of blast furnace. Secondly, combustion behavior of oil in the raceway and tuyere are discussed. The distribution of gas content was greatly changed, the location of CO, H{sub 2} generation was near the tuyere; the temperature peak shifts from near the raceway boundary to the tuyere. Oxygen concentration and blast velocity were two important factors, it was found that increasing excess oxygen ratio 0.9 to 1.3, the combustion time of oil decreases 0.5 msec, an increase of the blast velocity results in increasing the flame length. In addition, the nozzle position and oil rate had large effects on the combustion of oil. Based on these results, the limit of oil injection is also discussed, soot formation is the main reason limiting to further increase oil injection rate, it was viewed that there were three types of soot which were generated under blast furnace operating conditions. The reason generating soot is the incomplete conversion of the fuel. Finally, three methods improving combustion of oil in the raceway are given: Improvement of oil

Research achievement report for fiscal 1998 on the development of high-performance industrial furnaces. Research and development of high-performance industrial furnaces and the like (2); 1998 nendo koseino kogyoro no kaihatsu ni kansuru kenkyu seika hokokusho. Koseino kogyoro nado ni kansuru kenkyu kaihatsu (2)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Volume 2 named above contains part of research achievement reports and individual research achievement reports. The aluminum melting furnace working group research achievement report covers aluminum melting furnace operating patterns, concentrated impinging flame mode and dispersed impinging flame mode, and honeycomb and ball structures in heat storing bodies. The tubular heater working group report mentions the application of this facility to oil heating furnaces, studies and investigations for the embodiment of real systems using the tubular heater, and tests conducted in a furnace with plural heating tube lines. The individual research achievement reports elaborate on the development of technologies of heat transfer optimization under unsteady conditions in the steel material heating process, research and development of high-efficiency heat transfer technologies, development of heating furnace geometry optimization technologies, research and development of a high-performance controlled atmosphere heat treatment furnace, development of high-efficiency heat transfer technologies in high-temperature jet flame heating, development of heat uniformity improvement technologies for example for the steel material heating process, construction of optimum combustion control technologies for the regenerative burner furnace, research concerning laser-aided measurement in industrial furnaces, etc. (NEDO)

Evaporation heat transfer and pressure drop of R-410A in a 7.0 mm O.D. microfin tube at low flow rates

International Nuclear Information System (INIS)

Kim, Hae Hyun

2015-01-01

Microfin tubes having an outside diameter (O.D.) of 7.0 mm are widely used in residential air conditioning systems and heat pumps. It is known that the mass fluxes for air conditioners and heat pumps under partial load conditions are several tens of kg/m 2 s. However, literature surveys reveal that previous investigations were limited to mass flux over 100 kg/m 2 s. In this study, we conduct R-410A evaporation heat-transfer tests at low mass fluxes (50-250 kg/m 2 s) using a 7.0 mm O.D. microfin tube. During the test, the saturation temperature was maintained at 8 degrees celsius, and the heat flux was maintained at 4.kW/m"2. For comparison purposes, we also test a smooth tube with a 7.0 mm O.D. The results showed that the heat-transfer enhancement factor of the microfin tube increased as the mass flux decreased up to 150 kg/m 2 s, which decreased as the mass flux further decreased. The reason for this was attributed to the change of the flow pattern from an annular flow to a stratified flow. Within the test range, the frictional pressure drops of the microfin tube were approximately the same as those of the smooth tube. We then compare experimental data obtained with the predictions obtained for the existing correlations

Toward an early detection of PWR control rod anomalous dropping

International Nuclear Information System (INIS)

Blazquez, J.; Vallejo, I.

1998-01-01

Some anomalous PWR control rods dropping occurred in the past. It is assumed to be caused by a geometrical deformation of its guide tube, which might be related with neutron fluence and its sharp changes. Now at days, this problem is an open field of research, oriented to the understanding and prevention of the event. Work here is focused toward early detection. A differential equation modelling control rod free fall movement is found. There result three acceleration terms: gravity; friction with fluid; and friction with its guide tube. From recorded Plant measurements, both friction coefficients are estimated. The one from guide tube experiences a large variation in case of anomalous dropping; so relationship with neutron fluence is proposed for the prevention purpose. (Author)

Effects of fin shape on condensation in herringbone microfin tubes

Energy Technology Data Exchange (ETDEWEB)

Miyara, Akio [Saga University (Japan). Dept. of Mechanical Engineering; Otsubo, Yusuke; Ohtsuka, Satoshi; Mizuta, Yoshihiko [Saga University (Japan). Graduate School of Science and Engineering

2003-06-01

Effects of fin height and helix angle on condensation inside a herringbone microfin tube have been experimentally investigated with five types of herringbone microfin tubes. Heat transfer coefficients are about 2-4 times higher than that of the helical microfin tube under high mass velocity conditions. In the low mass velocity, they are equal to that of the helical microfin tube. The heat transfer enhancement increases with fin height up to 0.18 mm; higher fin heights show enhancement values similar to the 0.18 mm results. Pressure drop increases with the fin height. Larger helix angle yields higher heat transfer and higher pressure drop. For the lowest fin and/or smallest helix angle, the pressure drop is comparable with that of the helical microfin tube, while the heat transfer enhancement is higher. The enhancement mechanism is discussed from flow pattern observations. Effect of mass transfer resistance for R410A is estimated and negligible effects have been proved. (author)

Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces

International Nuclear Information System (INIS)

Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

2014-01-01

This paper shows the different types of furnaces for roasting cinnabar, used in the metallurgy of quicksilver over the centuries of exploitation of the Almaden Mines (Spain). Some of these techniques are part of our industrial heritage. They have contributed to name UNESCO World Heritage Site the vast technological legacy of these mines recently. This research contributes to close the long way of metallurgical activity from aludel furnaces until Pacif furnaces, first and lasted technology to produce on an industrial scale. It is delved into the most relevant aspects having to do with the type, evolution and number of furnaces existing on each of the periods. (Author)

Experimental studies on the evaporative heat transfer and pressure drop of CO{sub 2} and CO{sub 2}/propane mixtures flowing upward in smooth and micro-fin tubes with outer diameter of 5 mm for an inclination angle of 45

Energy Technology Data Exchange (ETDEWEB)

Cho, Jin Min; Kim, Min Soo [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea); Kim, Yong Jin [School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

2010-08-15

Heat transfer characteristics show different tendency according to the tube orientations such as horizontal, vertical, and inclined positions. In this study, evaporative heat transfer characteristics and pressure drop of CO{sub 2} and CO{sub 2}/propane mixtures flowing upward are investigated in inclined smooth and micro-fin tubes. Smooth and micro-fin tubes with outer diameter of 5 mm and length of 1.44 m with inclination angle of 45 were chosen as test tubes. Average inner diameters of test tubes are 4.0 mm (smooth tube) and 4.13 mm (micro-fin tube). The tests were conducted at mass fluxes from 212 to 656 kg/m{sup 2} s, saturation temperatures from -10 to 30 C and heat fluxes from 15 to 60 kW/m{sup 2} for CO{sub 2}. In addition, for CO{sub 2}/propane mixtures, the test was carried out at inlet temperatures from -10 to 30 C for several compositions (75/25, 50/50, 25/75 wt%) with the same mass fluxes, heat fluxes applied for CO{sub 2}. Heat transfer coefficients in inclined tube are approximately 1.8-3 times higher than those in horizontal tube and the average pressure drop of inclined tube exists between that of horizontal and vertical tubes. (author)

Smelting of high-quality boiler steel in large-load arc furnaces

Energy Technology Data Exchange (ETDEWEB)

Kablukovskij, A F; Breus, V M; Tyurin, E I; Khristich, V D; Dumchev, Ya P [Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR)

1975-02-01

High-grade steel can be obtained in large-capacity furnaces if the smelting technology used takes account of the size of the aggregates, the course of the metal fusion process, interaction with slag, furnace atmosphere, reducing agents, and other process characteristics. 12Kh1MF boiler steel smelted in a 100-ton electric arc furnace by an oxidizing process with oxygen bath blow and cast by the siphon method into 6.5-ton ingots using a slag-forming mixture (240 mm diameter billets and 219 to 245 mm diameter tubes) is satisfactory with regard to macro and microstructure, oxygen and nonmetallic oxide inclusion content, and mechanical properties. The stress rupture strength of 10/sup 5/ h at 570/sup 0/C is similar to that of open-hearth steel. Sulfides larger than a 3.5 spheroid have been detected in it. The nitrogen content of the electric steel is 0.0090 to 0.0120%, which is somewhat greater than usual in open-hearth metal. Of the oxygen inclusions in the steel, spinel-alumina predominates. Large inclusions were represented mainly by brittle silicates which appeared to be of exogenous origin.

Dropped Ceiling

OpenAIRE

Tabet, Rayyane

2012-01-01

On December 2nd 1950 the first drop of Saudi oil arrived to Lebanon via the newly constructed Trans-Arabian Pipeline, the world's longest pipeline and the largest American private investment in a foreign land. The 30inch wide structure which spanned 1213 kilometers passing through Saudi Arabia, Jordan, and Syria to end in Lebanon had required 3 years of planning and surveying, 2 years of installation, the fabrication of 256,000 tons of steel tubes, the employment of 30,000 workers, the ratifi...

Evaporation heat transfer and pressure drop of R-410A in a 7.0 mm O.D. microfin tube at low flow rates

Energy Technology Data Exchange (ETDEWEB)

Kim, Hae Hyun [Div. of Mechanical System Engineering, Incheon National University, Incheon (Korea, Republic of)

2015-09-15

Microfin tubes having an outside diameter (O.D.) of 7.0 mm are widely used in residential air conditioning systems and heat pumps. It is known that the mass fluxes for air conditioners and heat pumps under partial load conditions are several tens of kg/m{sup 2}s. However, literature surveys reveal that previous investigations were limited to mass flux over 100 kg/m{sup 2}s. In this study, we conduct R-410A evaporation heat-transfer tests at low mass fluxes (50-250 kg/m{sup 2}s) using a 7.0 mm O.D. microfin tube. During the test, the saturation temperature was maintained at 8 degrees celsius, and the heat flux was maintained at 4.kW/m{sup 2}. For comparison purposes, we also test a smooth tube with a 7.0 mm O.D. The results showed that the heat-transfer enhancement factor of the microfin tube increased as the mass flux decreased up to 150 kg/m{sup 2}s, which decreased as the mass flux further decreased. The reason for this was attributed to the change of the flow pattern from an annular flow to a stratified flow. Within the test range, the frictional pressure drops of the microfin tube were approximately the same as those of the smooth tube. We then compare experimental data obtained with the predictions obtained for the existing correlations.

Pressure tube reactor

International Nuclear Information System (INIS)

Susuki, Akira; Murata, Shigeto; Minato, Akihiko.

1993-01-01

In a pressure tube reactor, a reactor core is constituted by arranging more than two units of a minimum unit combination of a moderator sealing pipe containing a calandria tube having moderators there between and a calandria tube and moderators. The upper header and a lower header of the calandria tank containing moderators are communicated by way of the moderator sealing tube. Further, a gravitationally dropping mechanism is disposed for injecting neutron absorbing liquid to a calandria gas injection portion. A ratio between a moderator volume and a fuel volume is defined as a function of the inner diameter of the moderator sealing tube, the outer diameter of the calandria tube and the diameter of fuel pellets, and has no influence to intervals of a pressure tube lattice. The interval of the pressure tube lattice is enlarged without increasing the size of the pressure tube, to improve production efficiency of the reactor and set a coolant void coefficient more negative, thereby enabling to improve self controllability and safety. Further, the reactor scram can be conducted by injecting neutron absorbing liquid. (N.H.)

Advanced steel reheat furnace

Energy Technology Data Exchange (ETDEWEB)

Moyeda, D.; Sheldon, M.; Koppang, R. [Energy and Environmental Research Corp., Irvine, CA (United States); Lanyi, M.; Li, X.; Eleazer, B. [Air Products and Chemicals, Inc., Allentown, PA (United States)

1997-10-01

Energy and Environmental Research Corp. (EER) under a contract from the Department of Energy is pursuing the development and demonstration of an Advanced Steel Reheating Furnace. This paper reports the results of Phase 1, Research, which has evaluated an advanced furnace concept incorporating two proven and commercialized technologies previously applied to other high temperature combustion applications: EER`s gas reburn technology (GR) for post combustion NOx control; and Air Product`s oxy-fuel enrichment air (OEA) for improved flame heat transfer in the heating zones of the furnace. The combined technologies feature greater production throughput with associated furnace efficiency improvements; lowered NOx emissions; and better control over the furnace atmosphere, whether oxidizing or reducing, leading to better control over surface finish.

Furnace and Heat Recovery Area Design and Analysis for Conceptual Design of Supercritical O2-Based PC Boiler

International Nuclear Information System (INIS)

Andrew Seltzer

2006-01-01

The objective of the furnace and heat recovery area design and analysis task of the Conceptual Design of Supercritical Oxygen-Based PC Boiler study is to optimize the location and design of the furnace, burners, over-fire gas ports, and internal radiant surfaces. The furnace and heat recovery area were designed and analyzed using the FW-FIRE, Siemens, and HEATEX computer programs. The furnace is designed with opposed wall-firing burners and over-fire air ports. Water is circulated in the furnace by forced circulation to the waterwalls at the periphery and divisional wall panels within the furnace. Compared to the air-fired furnace, the oxygen-fired furnace requires only 65% of the surface area and 45% of the volume. Two oxygen-fired designs were simulated: (1) with cryogenic air separation unit (ASU) and (2) with oxygen ion transport membrane (OITM). The maximum wall heat flux in the oxygen-fired furnace is more than double that of the air-fired furnace due to the higher flame temperature and higher H 2 O and CO 2 concentrations. The coal burnout for the oxygen-fired case is 100% due to a 500 F higher furnace temperature and higher concentration of O 2 . Because of the higher furnace wall temperature of the oxygen-fired case compared to the air-fired case, furnace water wall material was upgraded from T2 to T92. Compared to the air-fired heat recovery area (HRA), the oxygen-fired HRA total heat transfer surface is 35% less for the cryogenic design and 13% less for the OITM design due to more heat being absorbed in the oxygen-fired furnace and the greater molecular weight of the oxygen-fired flue gas. The HRA tube materials and wall thickness are nearly the same for the air-fired and oxygen-fired design since the flue gas and water/steam temperature profiles encountered by the heat transfer banks are similar

Comparison of a burning mass ceramics coating in laboratory furnace and instrustrial furnace

International Nuclear Information System (INIS)

Soares, R.A.L.; Castro, J.R. de S.

2012-01-01

This work intends to analyze the differences obtained in the technological properties of a ceramic coating after firing in two distinct environments, laboratory furnace and industrial furnace. For this, was characterized a ceramic mass used in the production of porous coating. The analyzes were performed chemical, mineralogical and thermal mass in that. The specimens were obtained by compacting and burned in the maximum temperature of 1140 deg C in two furnaces, laboratory and industrial. The technological tests were performed linear shrinkage, water absorption, bulk density and mechanical strength. The microstructure was evaluated by ray-X diffraction and scanning electron microscopy. The results showed that both furnaces provided significant differences in analyzed specimens, such as increased strength and low water absorption in the fired samples in a laboratory furnace, for example. (author)

Laser-excited atomic-fluorescence spectrometry with electrothermal tube atomization.

Science.gov (United States)

Vera, J A; Leong, M B; Stevenson, C L; Petrucci, G; Winefordner, J D

1989-12-01

The performance of graphite-tube electrothermal atomizers is evaluated for laser-excited atomic-fluorescence spectrometry for several elements. Three pulsed laser systems are used to pump tunable dye lasers which subsequently are used to excite Pb, Ga, In, Fe, Ir, and Tl atoms in the hot graphite tube. The dye laser systems used are pumped by nitrogen, copper vapour and Nd:YAG lasers. Detection limits in the femtogram and subfemtogram range are typically obtained for all elements. A commercial graphite-tube furnace is important for the successful utilization of the laser-based method when the determination of trace elements is intended, especially when complicated matrices may be present.

CFD study of ejector flow behavior in a blast furnace gas galvanizing plant

Science.gov (United States)

Besagni, Giorgio; Mereu, Riccardo; Inzoli, Fabio

2015-02-01

In recent years, there has been a growing interest toward Blast Furnace Gas (BFG) as a low-grade energy source for industrial furnaces. This paper considers the revamping of a galvanic plant furnace converted to BFG from natural gas. In the design of the new system, the ejector on the exhaust line is a critical component. This paper studies the flow behavior of the ejector using a Computational Fluid Dynamics (CFD) analysis. The CFD model is based on a 3D representation of the ejector, using air and exhaust gases as working fluids. This paper is divided in three parts. In the first part, the galvanic plant used as case study is presented and discussed, in the second part the CFD approach is outlined, and in the third part the CFD approach is validated using experimental data and the numerical results are presented and discussed. Different Reynolds-Averaged Navier-Stokes (RANS) turbulence models ( k-ω SST and k-ɛ Realizable) are evaluated in terms of convergence capability and accuracy in predicting the pressure drop along the ejector. Suggestions for future optimization of the system are also provided.

Improving the thermal efficiency of a jaggery production module using a fire-tube heat exchanger.

Science.gov (United States)

La Madrid, Raul; Orbegoso, Elder Mendoza; Saavedra, Rafael; Marcelo, Daniel

2017-12-15

Jaggery is a product obtained after heating and evaporation processes have been applied to sugar cane juice via the addition of thermal energy, followed by the crystallisation process through mechanical agitation. At present, jaggery production uses furnaces and pans that are designed empirically based on trial and error procedures, which results in low ranges of thermal efficiency operation. To rectify these deficiencies, this study proposes the use of fire-tube pans to increase heat transfer from the flue gases to the sugar cane juice. With the aim of increasing the thermal efficiency of a jaggery installation, a computational fluid dynamic (CFD)-based model was used as a numerical tool to design a fire-tube pan that would replace the existing finned flat pan. For this purpose, the original configuration of the jaggery furnace was simulated via a pre-validated CFD model in order to calculate its current thermal performance. Then, the newly-designed fire-tube pan was virtually replaced in the jaggery furnace with the aim of numerically estimating the thermal performance at the same operating conditions. A comparison of both simulations highlighted the growth of the heat transfer rate at around 105% in the heating/evaporation processes when the fire-tube pan replaced the original finned flat pan. This enhancement impacted the jaggery production installation, whereby the thermal efficiency of the installation increased from 31.4% to 42.8%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Coal type and burnout performance

Energy Technology Data Exchange (ETDEWEB)

Lester, E.; Cloke, M. [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

1999-07-01

A variety of coals underwent refire tests in a drop tube furnace. Characteristics of the coal fractions, the pyrolysed char fractions and the refired char fractions were compared to determine links between coal composition, intermediate char products and burnout. 9 refs., 1 fig., 2 tabs.

Computational investigation of heat transfer and pressure drop in a typical louver fin-and-tube heat exchanger for various louver angles and fin pitches

Directory of Open Access Journals (Sweden)

Okbaz Abdulkerim

2017-01-01

Full Text Available In this study 3-D numerical simulations on heat transfer and pressure drop characteristics for a typical louver fin-and- double-row tube heat exchanger were carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles, fin pitch and Reynolds number, and reported in terms of Colburn j-factor and Fanning friction factor f. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles between 20° ≤Ө≤ 30°, louver pitch of Lp=3.8 mm and frontal velocities of U between 1.22 m/s - 3 m/s. In addition, flow visualization of detailed flow features results, such as velocity vectors, streamlines and temperature counters have been shown to understand heat transfer enhancement mechanism. The present results indicated that louver angle and fin pitch noticeably affected the thermal and hydraulic performance of heat exchanger. It has been seen that increasing louver angle, increases thermal performance while decreasing hydraulic performance associated to pressure drop for fin pitches of 3.2 mm and 2.5 mm. Fin pitch determines the flow behaviour that for fin pitch of 2 mm, increasing louver angle decreased heat transfer and pressure drop. Velocity vectors and streamlines give considerable information about the flow whether it is duct directed or louver directed. For all conditions the flow is louver directed.

Techniques for measurement of heat flux in furnace waterwalls of boilers and prediction of heat flux – A review

International Nuclear Information System (INIS)

Sankar, G.; Chandrasekhara Rao, A.; Seshadri, P.S.; Balasubramanian, K.R.

2016-01-01

Highlights: • Heat flux measurement techniques applicable to boiler water wall are elaborated. • Applications involving heat flux measurement in boiler water wall are discussed. • Appropriate technique for usage in high ash Indian coal fired boilers is required. • Usage of chordal thermocouple is suggested for large scale heat flux measurements. - Abstract: Computation of metal temperatures in a furnace waterwall of a boiler is necessary for the proper selection of tube material and thickness. An adequate knowledge of the heat flux distribution in the furnace walls is a prerequisite for the computation of metal temperatures. Hence, the measurement of heat flux in a boiler waterwall is necessary to arrive at an optimum furnace design, especially for high ash Indian coal fired boilers. Also, a thoroughly validated furnace model will result in a considerable reduction of the quantum of experimentation to be carried out. In view of the above mentioned scenario, this paper reviews the research work carried out by various researchers by experimentation and numerical simulation in the below mentioned areas: (i) furnace modeling and heat flux prediction, (ii) heat flux measurement techniques and (iii) applications of heat flux measurements.

Heat transfer and pressure drop characteristics of the tube bank fin heat exchanger with fin punched with flow redistributors and curved triangular vortex generators

Science.gov (United States)

Liu, Song; Jin, Hua; Song, KeWei; Wang, LiangChen; Wu, Xiang; Wang, LiangBi

2017-10-01

The heat transfer performance of the tube bank fin heat exchanger is limited by the air-side thermal resistance. Thus, enhancing the air-side heat transfer is an effective method to improve the performance of the heat exchanger. A new fin pattern with flow redistributors and curved triangular vortex generators is experimentally studied in this paper. The effects of the flow redistributors located in front of the tube stagnation point and the curved vortex generators located around the tube on the characteristics of heat transfer and pressure drop are discussed in detail. A performance comparison is also carried out between the fins with and without flow redistributors. The experimental results show that the flow redistributors stamped out from the fin in front of the tube stagnation points can decrease the friction factor at the cost of decreasing the heat transfer performance. Whether the combination of the flow redistributors and the curved vortex generators will present a better heat transfer performance depends on the size of the curved vortex generators. As for the studied two sizes of vortex generators, the heat transfer performance is promoted by the flow redistributors for the fin with larger size of vortex generators and the performance is suppressed by the flow redistributors for the fin with smaller vortex generators.

Methodology for full comparative assessment of direct gross glycerin combustion in a flame tube furnace

Energy Technology Data Exchange (ETDEWEB)

Maturana, Aymer Yeferson; Pagliuso, Josmar D. [Dept. of Mechanical Engineering. Sao Carlos School of Engineering. University of Sao Paulo, Sao Carlos, SP (Brazil)], e-mails: aymermat@sc.usp.br, josmar@sc.usp.br

2010-07-01

This study is to develop a methodology to identify and evaluate the emissions and heat transfer associated to combustion of gross glycerin a by-product of the Brazilian biodiesel manufacture process as alternative energy source. It aims to increase the present knowledge on the matter and to contribute to the improvement of the economic and environmental perspective of biodiesel industry. This methodology was considered to be used for assessment of gross glycerin combustion from three different types of biodiesel (bovine tallow, palm and soy). The procedures for evaluation and quantification of emissions of sulphur and nitrogen oxides, total hydrocarbons, carbon monoxide, carbon dioxide, and acrolein were analyzed, described and standardized. Experimental techniques for mutagenic and toxic effects assessment of gases similarly were analyzed and standardized, as well as the calorific power, the associate heat transfer and fundamentals operational parameters. The methodology was developed, using a full-instrumented flame tube furnace, continuous gas analyzers, a chromatograph, automatic data acquisition systems and other auxiliary equipment. The mutagenic and toxic effects of the study was based on Tradescantia clone KU-20, using chambers of intoxication and biological analytical techniques previously developed and others were specially adapted. The benchmark for the initial set up was based on the performance evaluation of the previous equipment tested with diesel considering its behavior during direct combustion. Finally, the following factors were defined for the combustion of crude glycerin, configurations of equipment types, operational parameters such as air fuel ratio adiabatic temperature and other necessary aspect for successful application of the methodology. The developed and integrated methodology was made available to the concern industry, environmental authorities and researchers as procedures to access the viability of gross glycerin or similar fuels as

Furnace

Energy Technology Data Exchange (ETDEWEB)

Osintsev, V V; Khidiyatov, A M

1981-01-01

The purpose of the invention is to improve the operating efficiency of the furnace device containing prefurnaces connected to the main combustion chamber. For this purpose in the proposed furnace device is equipped with prefurnaces with burners, rectangular vertical chamber of combustion is equipped with central hearth projection. As indicated by studies, the hearth projection of the indicated projections promotes the development of transverse streams which guarantee effective mixing of the combustion products in the upper part of the combustion chamber 3. This reduces the nonuniformity of temperature at the outlet from the latter, decreases the probability of slagging and hot spots on the heating surface.

Effects of Biomass Feedstock on the Yield and Reactivity of Soot from Fast Pyrolysis at High Temperatures

DEFF Research Database (Denmark)

Trubetskaya, Anna; Jensen, Peter A.; Glarborg, Peter

This study investigated the effect of feedstock on the yield, nanostructure and reactivity of soot. Woody and herbaceous biomass were pyrolyzed at high heating rates and temperatures of 1250 and 1400°C in a drop tube furnace. The collected solid residues were structurally characterized by electro...

Vlasov simulations of parallel potential drops

Directory of Open Access Journals (Sweden)

H. Gunell

2013-07-01

Full Text Available An auroral flux tube is modelled from the magnetospheric equator to the ionosphere using Vlasov simulations. Starting from an initial state, the evolution of the plasma on the flux tube is followed in time. It is found that when applying a voltage between the ends of the flux tube, about two thirds of the potential drop is concentrated in a thin double layer at approximately one Earth radius altitude. The remaining part is situated in an extended region 1–2 Earth radii above the double layer. Waves on the ion timescale develop above the double layer, and they move toward higher altitude at approximately the ion acoustic speed. These waves are seen both in the electric field and as perturbations of the ion and electron distributions, indicative of an instability. Electrons of magnetospheric origin become trapped between the magnetic mirror and the double layer during its formation. At low altitude, waves on electron timescales appear and are seen to be non-uniformly distributed in space. The temporal evolution of the potential profile and the total voltage affect the double layer altitude, which decreases with an increasing field aligned potential drop. A current–voltage relationship is found by running several simulations with different voltages over the system, and it agrees with the Knight relation reasonably well.

Destructive investigations of decommissioned guide tubes: characterization of wear

International Nuclear Information System (INIS)

Ambard, A.; Lina, A.; Bosselut, D.; Deforge, D.; Robinot, P.; Thebault, Y.; Paulhies, M.; Maingot, S.

2011-01-01

The wear of control rods has been a major maintenance concern for EDF since the nineties. Surface treatment of the rods (nitriding, chrome plating) were developed to deal with this issue. However, the question came to know whether the guiding tube in which those new control rods are inserted are also worn. EDF interest into guide tube wear has been renewed by the slow increase of the drop time in B06 position. EDF performed field examinations and some laboratory experiments to answer to this question. Two guide tubes were extracted from various cores. They were chosen due to their different positions within the core and the different nature of their counter bodies (different control rods surface treatment). Their continuous part were sliced to reduce their activity. Their dimensions were measured and compared to the nominal dimensions. Wear was evidenced with a low level. It is mainly concentrated around the notch. Some distinctions could be made depending on the guiding tube examined. Metallographic examinations were performed using SEM. The wear patterns of the guiding tubes appear similar from those of the control rods, which means that similar wear mechanisms must be involved. A tentative explanation of the increase of the rod drop time in position B06 is proposed. A tentative explanation of the low increase of rod drop time is presented. It could result from the conjunction of a larger pressing force in B06 position than in other position of the core as well as the conformal contact observed. The conformal contact in itself could results from the larger pressing force and the use of hardened rods. The findings of these field examinations have comforted EDF strategy concerning B06 guide tubes: they are changed before their drop time reaches a critical value. (authors)

Non-slag co-gasification of biomass and coal in entrained-bed furnace

Science.gov (United States)

Itaya, Yoshinori; Suami, Akira; Kobayashi, Nobusuke

2018-02-01

Gasification is a promising candidate of processes to upgrade biomass and to yield clean gaseous fuel for utilization of renewable energy resources. However, a sufficient amount of biomass is not always available to operate a large scale of the plant. Co-gasification of biomass with coal is proposed as a solution of the problem. Tar emission is another subject during operation in shaft or kiln type of gasifiers employed conventionally for biomass. The present authors proposed co-gasification of biomass and coal in entrained-bed furnace, which is a representative process without tar emission under high temperature, but operated so to collect dust as flyash without molten slag formation. This paper presents the works performed on co-gasification performance of biomass and pulverized coal to apply to entrained-bed type of furnaces. At first, co-gasification of woody powder and pulverized coal examined using the lab-scale test furnace of the down-flow entrained bed showed that the maximum temperatures in the furnace was over 1500 K and the carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time in the furnace was as short as a few seconds. Non-slag co-gasification was carried out successfully without slag formation in the furnace if coal containing ash with high fusion temperature was employed. The trend suggesting the effect of reaction rate enhancement of co-gasification was also observed. Secondary, an innovative sewage sludge upgrading system consisting of self-energy recovery processes was proposed to yield bio-dried sludge and to sequentially produce char without adding auxiliary fuel. Carbonization behavior of bio-dried sludge was evaluated through pyrolysis examination in a lab-scale quartz tube reactor. The thermal treatment of pyrolysis of sludge contributed to decomposition and removal of contaminant components such as nitrogen and sulfur. The gasification kinetics of sludge and coal was also determined by a

A simple method for preparing superconducting FeSe pellets without sealing in evacuated silica tubes

DEFF Research Database (Denmark)

Grivel, Jean-Claude

2017-01-01

Superconducting tetragonal FeSe pellets were made by reacting mixtures of elemental Fe and Se powders in argon atmosphere without sealing in evacuated silica tubes. A simple tube furnace has been used. Although the tube's material consisted of quartz, an alumina tube could be used as well. X......-ray pure samples with onset of superconducting transition between 8.0K and 8.5K were obtained under specific heat treatment conditions. Residual, unreacted Fe particles could be virtually eliminated through prolonged annealing. A key factor for the synthesis of good samples consists in using processing...

Fouling of heat exchanger surfaces by dust particles from flue gases of glass furnaces

Energy Technology Data Exchange (ETDEWEB)

Mutsaers, P.L.M.; Beerkens, R.G.C.; Waal, H. de (Nederlandse Centrale Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek, Delft. Inst. of Applied Physics)

1989-08-01

Fouling by dust particles generally leads to a reduction of the heat transfer and causes corrosion of secondary heat exchangers. A deposition model, including thermodynamic equilibrium calculations, has been derived and applied to describe the deposition (i.e. fouling) process and the nature of the deposition products in a secondary heat exchanger. The deposition model has been verified by means of laboratory experiments, for the case of flue gases from soda-lime glass furnaces. Corrosion of iron-containing metallic materials, caused by the deposition products, has been briefly investigated with the same equipment. There is a close similarity between the experimental results and model calculations. The largest deposition rates from flue gases on cylindrical tubes in cross-flow configuration, are predicted and measured at the upstream stagnation point. The lowest deposition rates are determined at downstream stagnation point locations. At tube surface temperatures of approximately 520 to 550 K, the fouling rate on the tube reaches a maximum. In this temperature region NaHSO{sub 4} is the most important deposition product. This component is mainly formed at temperatures from 470 up to 540 K. The compound Na{sub 3}H(SO{sub 4}){sub 2} seems to be stable up to 570 K, for even higher temperatures Na{sub 2}SO{sub 4} has been found. These deposition products react with iron, SO{sub 3}, oxygen and water vapour forming the complex corrosion product Na{sub 3}Fe(SO{sub 4}){sub 3}. NaHSO{sub 4}, which is formed at tube surface temperatures below 540 K, causes more severe corrosion of iron-containing materials than Na{sub 2}SO{sub 4}. Maintaining temperatures of the heat exchanger surfaces above 550 to 600 K reduces the fouling tendency and corrosion in case of flue gases from oil-fired soda-lime glass furnaces. (orig.).

Pressure Drop Versus Flow Rate Analysis of the Limited Streamer Tube Gas System of the BaBar Muon Detector Upgrade

International Nuclear Information System (INIS)

Yi, M.

2004-01-01

It has been proposed that Limited Streamer Tubes (LST) be used in the current upgrade of the muon detector in the BaBar detector. An LST consists of a thin silver plated wire centered in a graphite-coated cell. One standard LST tube consists of eight such cells, and two or three such tubes form an LST module. Under operation, the cells are filled with a gas mixture of CO 2 , argon and isobutane. During normal operation of the detector, the gas will be flushed out of the system at a constant low rate of one volume change per day. During times such as installation, however, it is often desired to flush and change the LST gas volumes very rapidly, leading to higher than normal pressure which may damage the modules. This project studied this pressure as a function of flow rate and the number of modules that are put in series in search of the maximal safe flow rate at which to flush the modules. Measurements of pressure drop versus flow rate were taken using a flow meter and a pressure transducer on configurations of one to five modules put in series. Minimal Poly-Flo tubing was used for all connections between test equipment and modules. They contributed less than 25% to all measurements. A ratio of 0.00022 ± 0.00001 mmHg per Standard Cubic Centimeter per Minute (SCCM) per module was found, which was a slight overestimate since it included the contributions from the tubing connections. However, for the purpose of finding a flow rate at which the modules can be safely flushed, this overestimate acts as a safety cushion. For a standard module with a volume of 16 liters and a known safe overpressure of 2 inches of water, the ratio translates into a flow rate of 17000 ± 1000SCCM and a time requirement of 56 ± 5 seconds to flush an entire module

Burnout in the horizontal tubes of a furnace waterwall panel

Energy Technology Data Exchange (ETDEWEB)

B.Y. Kamenetskii [All-Russia Research Institute of Nuclear Power Engineering (OAO VNIIAM), Moscow (Russian Federation)

2009-07-01

An experimental study of heat transfer that occurs in tubes nonuniformly heated over the perimeter at low velocities of subcooled water flowing in them is presented. Experiments with unsteady supply of heat made it possible to determine heat fluxes under burnout conditions. Unusually low values of critical heat fluxes were obtained under such conditions.

Burnout in the horizontal tubes of a furnace waterwall panel

Science.gov (United States)

Kamenetskii, B. Ya.

2009-08-01

An experimental study of heat transfer that occurs in tubes nonuniformly heated over the perimeter at low velocities of subcooled water flowing in them is presented. Experiments with unsteady supply of heat made it possible to determine heat fluxes under burnout conditions. Unusually low values of critical heat fluxes were obtained under such conditions.

Composition and microstructure of a furnace ash deposit from a coal-fired utility boiler

Energy Technology Data Exchange (ETDEWEB)

Fessler, R R

1980-07-01

An exploratory study of the structure and composition of furnace-ash deposits was carried out using optical metallography, electron microprobe analysis, scanning electron microscopy, and energy-dispersive X-ray analysis. The results of these analyses were supplemented by studies of particulate melting temperature using hot-stage microscopy to measure melting temperature, and energy-dispersive X-ray analyses to measure composition of melted particles. It was found that the general structure of the ash deposit was a matrix of glassy, spherical particles having a wide range of composition in which unfused particles containing iron oxide and calcium oxide were dispersed. At the imprint of the tube surface a considerable concentration of calcium, sulphur and iron was found. Near the fused outer surface of the deposit, the glassy materials had melted into a porous, glassy slag containing spherical globules of iron oxide combined with other materials. There were no systematic compositional gradients from the tube surface to the fused outer layer except for the sulfur layer found only at the tube surface. However, there were significant differences in composition from particle to particle and these differences were similar to those found in the coal mineral matter as isolated by low-temperature ashing. Single particles of low-temperature ash were found having low fusion temperatures, in the range of fusion temperatures for particles in furnance has. Thus, the glassy spheres found in furnace deposits could originate from single coal particles, without the need of interactions among coal particles or ash particles.

Evaluation of the crack initiation of curved compact tension specimens of a Zr-2.5Nb pressure tube using the unloading compliance and direct current potential drop methods

International Nuclear Information System (INIS)

Jeong, Hyeon Cheol; Ahn, Sang Bok; Park, Joong Chul; Kim, Young Suk

2005-01-01

Zr-2.5Nb pressure tubes, carrying fuel bundles and heavy water coolant inside, degrade due to neutron irradiation and hydrogen embrittlement during their operation in heavy water reactors. The safety criterion for the Zr-2.5Nb tubes to meet is a leak-before-break (LBB) requirement. To evaluate a safety margin related to the LBB criterion, facture toughness of the pressure tubes are to be determined periodically with their operational time. For a reliable evaluation of the LBB safety criterion of the pressure tubes, it is required to precisely determine their fracture toughness. Since the fracture toughness or J of the pressure tubes is determined only by the extended crack length, it is important to reliably and precisely evaluate the advanced crack length. However, the problem lies with the detection of the crack opening point because prior plastic deformation before a start of the crack makes it difficult. The aim of this work is to evaluate which method can define the crack initiation point in the Zr- 2.5Nb compact tension specimens more precisely between the unloading compliance method with a crack opening displacement (COD) gauge and the direct current potential drop (DCPD) methods

Manufacture of seamless stainless steel tubings and related equipment

International Nuclear Information System (INIS)

Wali, D.K.; Chaudhary, S.

1997-01-01

Production of seamless tubes for special application is one of the important production activities of Nuclear Fuel Complex (NFC), Hyderabad. NFC had set up facility of Hot Extrusion Press and Cold Pilger Mills with related finishing and inspection equipment for manufacturing quality seamless tubes of zirconium alloy for application in nuclear power reactors in early 70''s. Being aware that the demand for seamless tube in a developing economy gradually increases till it reaches around 30 to 40% of the total requirement of tubes and pipes and also of the fact that manufacturing technology developed for production of zircaloy seamless tubes for nuclear application, can easily be harnessed and spinned off for production of seamless tubes in materials generally difficult to hot roll (in other than extrusion process), NFC augmented its seamless tube manufacturing facility by adding, a vertical piercing press, series of induction furnaces and large size pilger mills to meet existing market demand of power sector, engineering, fertilisers and petro chemical industries and any other specialised applications

Phase separation and pressure drop of two-phase flow in vertical manifolds

International Nuclear Information System (INIS)

Zetzmann, K.

1982-01-01

The splitting of a two-phase mass flow in a tube manifold results in a separation between liquid and gas phase. A study is presented of the phase distribution and the related two-phase pressure drop for vertical manifolds in the technically relevant geometry and flow parameter region of an air-water-flow. At the outlet changes in the gas/fluid-radio are observed which are proportional to this ratio at the inlet. The separation characteristic strongly depends on the massflow through the junction. Empirical equations are given to calculate the separation. Measuring the pressure drop at main- and secondary tube of the manifold the additional pressure drop can be obtained. If these results are related with the dynamic pressure at the inlet, two-phase resistance coefficients can be deduced, which may be tested by empirical relations. (orig.) [de

Waste and dust utilisation in shaft furnaces

Energy Technology Data Exchange (ETDEWEB)

Senk, D.; Babich, A.; Gudenau, H.W. [Rhein Westfal TH Aachen, Aachen (Germany)

2005-07-01

Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilised e.g. in agglomeration processes (sintering, pelletising or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverised coal (PC) has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

A study of burning processes of fossil fuels in straitened conditions of furnaces in low capacity boilers by an example of natural gas

Science.gov (United States)

Roslyakov, P. V.; Proskurin, Y. V.; Khokhlov, D. A.; Zaichenko, M. N.

2018-03-01

The aim of this work is to research operations of modern combined low-emission swirl burner with a capacity of 2.2 MW for fire-tube boiler type KV-GM-2.0, to ensure the effective burning of natural gas, crude oil and diesel fuel. For this purpose, a computer model of the burner and furnace chamber has been developed. The paper presents the results of numerical investigations of the burner operation, using the example of natural gas in a working load range from 40 to 100%. The basic features of processes of fuel burning in the cramped conditions of the flame tube have been identified to fundamentally differ from similar processes in the furnaces of steam boilers. The influence of the design of burners and their operating modes on incomplete combustion of fuel and the formation of nitrogen oxides has been determined.

Alkaline carbonates in blast furnace process

Directory of Open Access Journals (Sweden)

P. Besta

2014-10-01

Full Text Available The production of iron in blast furnaces is a complex of physical, chemical and mechanical processes. The input raw materials contain not only metallic components, but also a number of negative elements. The most important negative elements include alkaline carbonates. They can significantly affect the course of the blast furnace process and thus the overall performance of the furnace. As a result of that, it is essential to accurately monitor the alkali content in the blast furnace raw materials. The article analyzes the alkali content in input and output raw materials and their impact on the blast furnace process.

Industrial furnace with improved heat transfer

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, M.; Lingle, T.M.

1992-07-07

This patent describes an industrial furnace for heating work which emits volatiles during heating. It comprises a generally cylindrical, closed end furnace section defining a sealable heat transfer chamber for heating work disposed therein; fan means for directing furnace atmosphere as a swirling wind mass about the interior of the furnace section over a portion thereof; heat means for heating the wind mass within the fan chamber; and an incineration track formed as a circumferentially extending groove about the exterior of the furnace section and in heat transfer relationship with and situated at least to extend about a portion of the fan chamber.

Modeling, Prediction, and Control of Heating Temperature for Tube Billet

Directory of Open Access Journals (Sweden)

Yachun Mao

2015-01-01

Full Text Available Annular furnaces have multivariate, nonlinear, large time lag, and cross coupling characteristics. The prediction and control of the exit temperature of a tube billet are important but difficult. We establish a prediction model for the final temperature of a tube billet through OS-ELM-DRPLS method. We address the complex production characteristics, integrate the advantages of PLS and ELM algorithms in establishing linear and nonlinear models, and consider model update and data lag. Based on the proposed model, we design a prediction control algorithm for tube billet temperature. The algorithm is validated using the practical production data of Baosteel Co., Ltd. Results show that the model achieves the precision required in industrial applications. The temperature of the tube billet can be controlled within the required temperature range through compensation control method.

Automated, High Temperature Furnace for Glovebox Operation

International Nuclear Information System (INIS)

Neikirk, K.

2001-01-01

The Plutonium Immobilization Project (PIP), to be located at the Savannah River Site SRS, is a combined development and testing effort by Lawrence Livermore National Laboratory (LLNL), Westinghouse Savannah River Company (WSRC), Pacific Northwest National Laboratory (PNNL), Argonne National Laboratory (ANL), and the Australian National Science and Technology Organization (ANSTO). The Plutonium Immobilization process involves the disposition of excess plutonium by incorporation into ceramic pucks. As part of the immobilization process, furnaces are needed for sintering the ceramic pucks. The furnace being developed for puck sintering is an automated, bottom loaded furnace with insulating package and resistance heating elements located within a nuclear glovebox. Other furnaces types considered for the application include retort furnaces and pusher furnaces. This paper, in part, will discuss the furnace technologies considered and furnace technology selected to support reliable puck sintering in a glovebox environment

Calculations in furnace technology

CERN Document Server

Davies, Clive; Hopkins, DW; Owen, WS

2013-01-01

Calculations in Furnace Technology presents the theoretical and practical aspects of furnace technology. This book provides information pertinent to the development, application, and efficiency of furnace technology. Organized into eight chapters, this book begins with an overview of the exothermic reactions that occur when carbon, hydrogen, and sulfur are burned to release the energy available in the fuel. This text then evaluates the efficiencies to measure the quantity of fuel used, of flue gases leaving the plant, of air entering, and the heat lost to the surroundings. Other chapters consi

Effects of several types of biomass fuels on the yield, nanostructure and reactivity of soot from fast pyrolysis at high temperatures

DEFF Research Database (Denmark)

Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn

2016-01-01

This study presents the effect of biomass origin on the yield, nanostructure and reactivity of soot. Soot was produced from wood and herbaceous biomass pyrolysis at high heating rates and at temperatures of 1250 and 1400 °C in a drop tube furnace. The structure of solid residues was characterized...

Electrostatic Levitation Furnace for the ISS

Science.gov (United States)

Murakami, Keiji; Koshikawa, Naokiyo; Shibasaki, Kohichi; Ishikawa, Takehiko; Okada, Junpei; Takada, Tetsuya; Arai, Tatsuya; Fujino, Naoki; Yamaura, Yukiko

2012-01-01

JAXA (Japan Aerospace Exploration Agency) has just started the development of Electrostatic Levitation Furnace to be launched in 2014 for the ISS. This furnace can control the sample position with electrostatic force and heat it above 2000 degree Celsius using semiconductor laser from four different directions. The announcement of Opportunity will be issued soon for this furnace. In this paper, we will show the specifications of this furnace and also the development schedule

Final Technical Report - High-Performance, Oxide-Dispersion-Strengthened Tubes for Production of Ethylene adn Other Industrial Chemicals

Energy Technology Data Exchange (ETDEWEB)

McKimpson, Marvin G.

2006-04-06

strengthened materials produced using mechanical alloying technology. To minimize cost, the bimetallic tube is produced by direct powder co-extrusion. This technology has potential for domestic energy savings of up to 4.1 trillion BTU/year (4.3 x 1015J/year) and a reduction of 370,000 tons (340,000 tonnes) of CO2 emissions in short-residence-time ethylene furnaces. This represents an energy savings and CO2 emissions reduction of about 3.3%. If the technology is also applied to other types of ethylene pyrolysis furnaces, total energy savings and CO2 emissions reductions could increase by up to five times. The work involved: Developing powder and consolidation processing protocols to produce an oxide-dispersion strengthened variant of Alloy 803 exhibiting creep strength comparable to Incoloy? Alloy MA956, Developing a direct powder co-extrusion protocol for fabricating co-extruded bimetallic Incoloy? Alloy MA956 / ODS Alloy 803 tubes, Characterizing the properties of the ODS Alloy 803 material, the welding characteristics of the bimetallic tubes, and the coking characteristics of the Incoloy? MA956 alloy, and Documenting the potential energy savings and user requirements for these bimetallic pyrolysis furnace tubes. The project demonstrated that oxide dispersion strengthened Alloy 803 can be produced successfully using conventional mechanical alloying technology. The oxide dispersion strengthened bimetallic radiant coil technology explored under this program has significant potential for energy savings and productivity improvements for domestic ethylene producers. In today's competitive market, however, domestic furnace manufacturers and ethylene producers appear reluctant to pay any cost premium for higher-performance coil materials offering either higher temperature capabilities or longer service life. Interest in oxide dispersion strengthened radiant coils is likely to increase if furnace and ethylene producers begin to focus more on increasing tube wall temperatures to

Investigation of the pressure drop inside a rectangular channel with a built-in U-shaped tube bundle heat exchanger

Directory of Open Access Journals (Sweden)

Xi-yue Liu

2017-01-01

Full Text Available A simplified approach which utilizes an isotropic porous medium model has been widely adopted for modeling the flow through a compact heat exchanger. With respect to situations where the compact heat exchangers are partially installed inside a channel, such as the application of recuperators in an intercooled recuperative engine, the use of an isotropic porous medium model needs to be carefully assessed because the flow passing through the heat exchanger is very complicated. For this purpose, in this study the isotropic porous medium model is assessed together with specific pressure–velocity relationships for flow field modeling inside a rectangular channel with a built-in double-U-shaped tube bundle heat exchanger. Firstly, experiments were conducted using models to investigate the relationship between the pressure drop and the inlet velocity for a specific heat exchanger with different installation angles inside a rectangular channel. Secondly, a series of numerical computations were carried out using the isotropic porous medium model and the pressure–velocity relationship was then modified by introducing correction coefficients empirically. Finally, a three-dimensional (3-D direct computation was made using a computational fluid dynamics (CFD method for the comparison of detailed flow fields. The results suggest that the isotropic porous medium model is capable of making precise pressure drop predictions given the reasonable pressure–velocity relationship but is unable to precisely simulate the detailed flow features.

Potential drop crack measurement systems for CANDU components

Energy Technology Data Exchange (ETDEWEB)

Sahney, R [Carleton Univ., Ottawa, ON (Canada)

1994-12-31

A project to develop an automated crack measurement system for CANDU pressure tube burst testing is currently underway. The system will utilize either Direct Current Potential Drop (DCPD) or Alternating Current Potential Drop (ACPD) techniques for crack measurement. The preliminary stage of the project involves testing and comparison of both ACPD and DCPD methods on a Zr - 2.5% Nb alloy plate with saw cuts (used to simulate cracks). Preliminary results show that both ACPD and DCPD techniques are capable of detecting cracks; further testing is in progress to determine the ability of each of the two systems to make accurate crack depth measurements. This paper will describe the two potential drop techniques and will present test results from the experimental program. (author). 10 refs., 7 figs.

Boiling and condensation in microfin tubes

Science.gov (United States)

Schlager, Lynn M.

A general overview of microfin tubes and their applications is presented. Manufacturing processes, commercial availability, experimental heat transfer, and pressure drop data for various refrigerants (including alternative refrigerants and refrigerant-oil mixtures), physical mechanisms of enhancement, and the incorporation of microfin tubes in common heat exchanger configurations are discussed. Microfin tubes, also known by various trade names, are characterized by numerous small fins which typically spiral down the inside wall of tubes at angles ranging from 10 to 30 degrees. The number of fins ranges from 48 to 70 with typical fin heights of 0.12 to 0.30 mm (fin height generally less than 3 percent of the inside diameter of the tube). Fin shapes may vary and the inside surface area of microfin tubes is 10 to 70 percent greater than the area of equivalent smooth tubes. Heat transfer can be enhanced by up to a factor of three with microfin tubes.

Constructal design of a blast furnace iron-making process based on multi-objective optimization

International Nuclear Information System (INIS)

Liu, Xiong; Chen, Lingen; Feng, Huijun; Qin, Xiaoyong; Sun, Fengrui

2016-01-01

For the fixed total raw material cost and based on constructal theory and finite time thermodynamics, a BFIM (blast furnace iron-making) process is optimized by taking a complex function as optimization objective. The complex function is integrated with HM (hot metal) yield and useful energy of the BF (blast furnace). The optimal cost distribution of raw materials (namely “generalized optimal construct”) is obtained. The effects of some parameters, such as oxygen enrichment, blast temperature and pulverized coal dosage, on the optimization results are analyzed. The results show that the HM yield, useful energy and complex function are, respectively, increased by 3.13%, 2.66% and 2.90% after generalized constructal optimization. The utilization efficiencies of the BFG (blast furnace gas) and slag are 41.3% and 57.1%, respectively, which means that the utilization potentials of the BFG and slag can be further exploited. Increasing pulverized coal dosage and decreasing the agglomerate ratio can increase the complex function. The performance the BFIM process can be improved by adjusting the oxygen enrichment, blast temperature, blast dosage, pressure ratio of the Brayton cycle's air compressor and relative pressure drop of the air compressor inlet to their optimal values, respectively, which are new findings of this paper. - Highlights: • Constructal optimization of a blast furnace iron-making process is performed. • Finite time thermodynamic model of open Brayton cycle is adopted. • Weighting function is taken as optimization objective. • Optimal cost distribution of the raw materials is obtained.

Automated, High Temperature Furnace for Glovebox Operation

International Nuclear Information System (INIS)

Neikirk, K.

2001-01-01

The U.S. Department of Energy will immobilize excess plutonium in the proposed Plutonium Immobilization Plant (PIP) at the Savannah River Site (SRS) as part of a two track approach for the disposition of weapons usable plutonium. As such, the Department of Energy is funding a development and testing effort for the PIP. This effort is being performed jointly by Lawrence Livermore National Laboratory (LLNL), Westinghouse Savannah River Company (WSRC), Pacific Northwest National Laboratory (PNNL), and Argonne National Laboratory (ANL). The Plutonium Immobilization process involves the disposition of excess plutonium by incorporation into ceramic pucks. As part of the immobilization process, furnaces are needed for sintering the ceramic pucks. The furnace being developed for puck sintering is an automated, bottom loaded furnace with insulting package and resistance heating elements located within a nuclear glovebox. Other furnaces considered for the application include retort furnaces and pusher furnaces. This paper, in part, will discuss the furnace technologies considered and furnace technology selected to support reliable puck sintering in a glovebox environment. Due to the radiation levels and contamination associated with the plutonium material, the sintering process will be fully automated and contained within nuclear material gloveboxes. As such, the furnace currently under development incorporates water and air cooling to minimize heat load to the glovebox. This paper will describe the furnace equipment and systems needed to employ a fully automated puck sintering process within nuclear gloveboxes as part of the Plutonium Immobilization Plant

Stress-Assisted Corrosion in Boiler Tubes

Energy Technology Data Exchange (ETDEWEB)

Preet M Singh; Steven J Pawel

2006-05-27

A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

Improved Casting Furnace Conceptual Design

Energy Technology Data Exchange (ETDEWEB)

Fielding, Randall Sidney [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tolman, David Donald [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-02-01

In an attempt to ensure more consistent casting results and remove some schedule variance associated with casting, an improved casting furnace concept has been developed. The improved furnace uses the existing arc melter hardware and glovebox utilities. The furnace concept was designed around physical and operational requirements such as; a charge sized of less than 30 grams, high heating rates and minimal additional footprint. The conceptual model is shown in the report as well as a summary of how the requirements were met.

Sensitive determination of cadmium using solidified floating organic drop microextraction-slotted quartz tube-flame atomic absorption spectroscopy.

Science.gov (United States)

Akkaya, Erhan; Chormey, Dotse Selali; Bakırdere, Sezgin

2017-09-20

In this study, solidified floating organic drop microextraction (SFODME) by 1-undecanol was combined with slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) for the determination of cadmium at trace levels. Formation of a complex with 4,4'-dimethyl-2,2'-bipyridine facilitated the extraction of cadmium from aqueous solutions. Several chemical variables were optimized in order to obtain high extraction outputs. Parameters such as concentration of the ligand, pH, and amount of buffer solution were optimized to enhance the formation of cadmium complex. The SFODME method was assisted by dispersion of extractor solvent into aqueous solutions using 2-propanol. Under the optimum extraction and instrumental conditions, the limit of detection and limit of quantitation values obtained for cadmium using the combined methods (SFODME-SQT-FAAS) were found to be 0.4 and 1.3 μg L -1 , respectively. Matrix effects on the method were also examined for tap water and wastewater, and spiked recovery results were found to be very satisfactory. Graphical Abstract SFODME-SQT-FAAS system for sensitive determination of cadmium.

Experimental and numerical studies of choked flow through adiabatic and diabatic capillary tubes

International Nuclear Information System (INIS)

Deodhar, Subodh D.; Kothadia, Hardik B.; Iyer, K.N.; Prabhu, S.V.

2015-01-01

Capillary tubes are extensively used in several cooling applications like refrigeration, electronic cooling etc. Local pressure variation in adiabatic straight capillary tube (mini channel) is studied experimentally and numerically with R134a as the working fluid. Experiments are performed on two straight capillary tubes. It is found that the diameter is the most sensitive design parameter of the capillary tube. Experiments are performed on five helically coiled capillary tubes to quantify the effect of pitch and curvature of helically coiled capillary tube on the pressure drop. Non dimensionalized factor to account coiling of capillary tube is derived to calculate mass flow rate in helically coiled capillary tubes. Flow visualization in adiabatic capillary tube confirms the bubbly nature of two phase flow. Numerical and experimental investigations in diabatic capillary tube suggest that the use of positive displacement pump and choking at the exit of the channel ensures flow stability. - Highlights: • Model is developed to design capillary tube in adiabatic and diabatic condition. • Effect of coil curvature on pressure drop is studied experimentally. • Correlation is developed to predict mass flow rate in helical capillary tubes. • Flow visualization is carried out to check the type of two phase flow. • Effect of choked flow on diabatic capillary tubes is studied experimentally.

Industrial and process furnaces principles, design and operation

CERN Document Server

Jenkins, Barrie

2014-01-01

Furnaces sit at the core of all branches of manufacture and industry, so it is vital that these are designed and operated safely and effi-ciently. This reference provides all of the furnace theory needed to ensure that this can be executed successfully on an industrial scale. Industrial and Process Furnaces: Principles, 2nd Edition provides comprehensive coverage of all aspects of furnace operation and design, including topics essential for process engineers and operators to better understand furnaces. This includes: the combustion process and its control, furnace fuels, efficiency,

Behavior of coke in large blast furnaces

Energy Technology Data Exchange (ETDEWEB)

Nakamura, N

1978-01-01

Three blast furnaces were quenched in operation and the contents were examined; the temperature distribution was also measured, using Tempil pellets. The furnaces examined included a low productivity one, which was examined to see what was wrong. Changes in the quality of coke as it descends in the furnace, and coke behavior in the raceway and hearth are reported. The functions required of coke, and the effects of poor coke quality, are explained, together with the coke quality required in large blast furnaces. A theoretical study of the role of coke in large blast furnaces is included.

3-D NUMERICAL STUDY AND COMPARISON OF ECCENTRIC AND CONCENTRIC ANNULAR-FINNED TUBE HEAT EXCHANGERS

Directory of Open Access Journals (Sweden)

FAROUK TAHROUR

2015-11-01

Full Text Available The use of 3-D computational fluid dynamics (CFD is proposed to simulate the conjugate conduction-convection of heat transfer problems in eccentric annularfinned tube heat exchangers. The numerical simulation results allow us to evaluate the heat transfer coefficient over fin surfaces, the fin efficiency and the pressure drop. The aim of the present paper is to determine the optimum tube position in the circular fin that maximizes heat dissipation and minimizes pressure drop. In addition, this study analyzes the effects of fin spacing and fin tube diameter on heat transfer and flow characteristics for a range of Reynolds numbers, 4500≤Re≤22500. A satisfactory qualitative and quantitative agreement was obtained between the numerical predictions and the results published in the literature. For small fin spacings, the eccentric annular finned tube is more efficient than the concentric one. Among the cases examined, the average heat transfer coefficient of the eccentric annular-finned tube, for a tube shift St =12 mm and a Reynolds number Re = 9923, was 7.61% greater than that of the concentric one. This gain is associated with a 43.09% reduction in pressure drop.

Convective boiling performance of refrigerant R-134a in herringbone and microfin copper tubes

Energy Technology Data Exchange (ETDEWEB)

Bandarra Filho, Enio P [Faculdade de Engenharia Mecanica, Universidade Federal de Uberlandia, Av. Joao Naves de Avila, 2160 Bloco 1M, Santa Monica, Uberlandia, MG (Brazil); Saiz Jabardo, Jose M [Escuela Politecnica Superior, Universidad de la Coruna, Calle Mendizabal s/n, 15403 Ferrol, Espana (Spain)

2006-01-01

This paper reports an experimental investigation of convective boiling heat transfer and pressure drop of refrigerant R-134a in smooth, standard microfin and herringbone copper tubes of 9.52mm external diameter. Tests have been conducted under the following conditions: inlet saturation temperature of 5{sup o}C, qualities from 5 to 90%, mass velocity from 100 to 500kgs{sup -1}m{sup -2}, and a heat flux of 5kWm{sup -2}. Experimental results indicate that the herringbone tube has a distinct heat transfer performance over the mass velocity range considered in the present study. Thermal performance of the herringbone tube has been found better than that of the standard microfin in the high range of mass velocities, and worst for the smallest mass velocity (G=100kgs{sup -1}m{sup -2}) at qualities higher than 50%. The herringbone tube pressure drop is higher than that of the standard microfin tube over the whole range of mass velocities and qualities. The enhancement parameter is higher than one for both tubes for mass velocities lower than 200kgs{sup -1}m{sup -2}. Values lower than one have been obtained for both tubes in the mass velocity upper range as a result of a significant pressure drop increment not followed by a correspondent increment in the heat transfer coefficient. (author)

Preliminary Study of Fermented Tapioca for Synthesis of Carbon Nano tubes

International Nuclear Information System (INIS)

Nurulhuda Ismail; Ying, P.Y.

2011-01-01

Carbon nano tubes had been produced by various precursor such as gas (methane, carbon dioxide), oil (camphor oil, olive oil, and cooking oil) and alcohol. Different methods used for carbon nano tubes synthesis like arc discharge method, laser ablation method and chemical vapour deposition method. In this experiment, thermal chemical vapour deposition method was selected for carbon nano tubes synthesis. Starting material of fermented tapioca was used as carbon source for the process. Argon gas flow were controlled at around 10-15 bubbles per minute and deposition time around 20 to 30 minute. Others parameters such as temperature of furnace 1 and 2, amount of inoculum and catalyst have been studied. The asThermogravimetri (TGA) was used to determine the volatile temperature of the mixing catalyst and fermented tapioca extract. The grown carbon nano tubes morphology was characterized through Raman spectroscopy, scanning and Field Emission Scanning Electron Microscopy (FESEM) techniques. The surface morphology and uniformity of carbon nano tubes are reliant to parameters used. (author)

Refractory of Furnaces to Reduce Environmental Impact

International Nuclear Information System (INIS)

Hanzawa, Shigeru

2011-01-01

The energy load of furnaces used in the manufacturing process of ceramics is quite large. Most of the environmental impact of ceramics manufacturing is due to the CO 2 produced from this high energy load. To improve this situation, R and D has focused on furnace systems and techniques of control in order to reduce energy load. Since furnaces are comprised of refractory, consideration of their mechanical and thermal characteristics is important. Herein are described several refractory types which were chosen through comparison of the characteristics which contribute to heat capacity reduction, heat insulating reinforcement and high emissivity, thereby improving thermal radiation heat transfer efficiency to the ceramic articles. One selected refractory material which will reduce the environmental impact of a furnace, chosen considering low heat capacity and high emissivity characteristics, is SiC. In this study, thermal radiation heat transfer efficiency improvement and its effect on ceramic articles in the furnace and oxidation behaviour were investigated at 1700K. A high density SiC refractory, built into the furnace at construction, has relatively high oxidation durability and has the ability to reduce environmental impact-CO 2 by 10 percent by decreasing the furnace's energy load. However, new oxidation prevention techniques for SiC will be necessary for long-term use in industrial furnaces, because passive to active oxidation transition behaviour of commercial SiC refractory is coming to close ideal.

Refractory of Furnaces to Reduce Environmental Impact

Science.gov (United States)

Hanzawa, Shigeru

2011-10-01

The energy load of furnaces used in the manufacturing process of ceramics is quite large. Most of the environmental impact of ceramics manufacturing is due to the CO2 produced from this high energy load. To improve this situation, R&D has focused on furnace systems and techniques of control in order to reduce energy load. Since furnaces are comprised of refractory, consideration of their mechanical and thermal characteristics is important. Herein are described several refractory types which were chosen through comparison of the characteristics which contribute to heat capacity reduction, heat insulating reinforcement and high emissivity, thereby improving thermal radiation heat transfer efficiency to the ceramic articles. One selected refractory material which will reduce the environmental impact of a furnace, chosen considering low heat capacity and high emissivity characteristics, is SiC. In this study, thermal radiation heat transfer efficiency improvement and its effect on ceramic articles in the furnace and oxidation behaviour were investigated at 1700K. A high density SiC refractory, built into the furnace at construction, has relatively high oxidation durability and has the ability to reduce environmental impact-CO2 by 10 percent by decreasing the furnace's energy load. However, new oxidation prevention techniques for SiC will be necessary for long-term use in industrial furnaces, because passive to active oxidation transition behaviour of commercial SiC refractory is coming to close ideal.

Model based energy benchmarking for glass furnace

International Nuclear Information System (INIS)

Sardeshpande, Vishal; Gaitonde, U.N.; Banerjee, Rangan

2007-01-01

Energy benchmarking of processes is important for setting energy efficiency targets and planning energy management strategies. Most approaches used for energy benchmarking are based on statistical methods by comparing with a sample of existing plants. This paper presents a model based approach for benchmarking of energy intensive industrial processes and illustrates this approach for industrial glass furnaces. A simulation model for a glass furnace is developed using mass and energy balances, and heat loss equations for the different zones and empirical equations based on operating practices. The model is checked with field data from end fired industrial glass furnaces in India. The simulation model enables calculation of the energy performance of a given furnace design. The model results show the potential for improvement and the impact of different operating and design preferences on specific energy consumption. A case study for a 100 TPD end fired furnace is presented. An achievable minimum energy consumption of about 3830 kJ/kg is estimated for this furnace. The useful heat carried by glass is about 53% of the heat supplied by the fuel. Actual furnaces operating at these production scales have a potential for reduction in energy consumption of about 20-25%

Solar Convective Furnace for Metals Processing

Science.gov (United States)

Patidar, Deepesh; Tiwari, Sheetanshu; Sharma, Piyush; Pardeshi, Ravindra; Chandra, Laltu; Shekhar, Rajiv

2015-11-01

Metals processing operations, primarily soaking, heat treatment, and melting of metals are energy-intensive processes using fossil fuels, either directly or indirectly as electricity, to operate furnaces at high temperatures. Use of concentrated solar energy as a source of heat could be a viable "green" option for industrial heat treatment furnaces. This paper introduces the concept of a solar convective furnace which utilizes hot air generated by an open volumetric air receiver (OVAR)-based solar tower technology. The potential for heating air above 1000°C exists. Air temperatures of 700°C have already been achieved in a 1.5-MWe volumetric air receiver demonstration plant. Efforts to retrofit an industrial aluminium soaking furnace for integration with a solar tower system are briefly described. The design and performance of an OVAR has been discussed. A strategy for designing a 1/15th-scale model of an industrial aluminium soaking furnace has been presented. Preliminary flow and thermal simulation results suggest the presence of recirculating flow in existing furnaces that could possibly result in non-uniform heating of the slabs. The multifarious uses of concentrated solar energy, for example in smelting, metals processing, and even fuel production, should enable it to overcome its cost disadvantage with respect to solar photovoltaics.

Energy Saving in Industrial Annealing Furnaces

Directory of Open Access Journals (Sweden)

Fatma ÇANKA KILIÇ

2018-03-01

Full Text Available In this study, an energy efficiency studies have been carried out in a natural gas-fired rolling mill annealing furnace of an industrial establishment. In this context, exhaust gas from the furnace has been examined in terms of waste heat potential. In the examinations that have been made in detail; waste heat potential was found as 3.630,31 kW. Technical and feasibility studies have been carried out to realize electricity production through an Organic Rankine Cycle (ORC system for evaluating the waste heat potential of the annealing furnace. It has been calculated that 1.626.378,88 kWh/year of electricity can be generated by using the exhaust gas waste heat of the annealing furnace through an ORC system to produce electric energy with a net efficiency of 16%. The financial value of this energy was determined as 436.032,18 TL/year and the simple repayment period of the investment was 8,12 years. Since the annealing period of the annealing furnace is 2800 hours/year, the investment has not been found to be feasible in terms of the feasibility studies. However, the investment suitability can be assured when the annealing furnace is operating at full capacity for 8,000 hours or more annually.

Design and Development of Tilting Rotary Furnace

Science.gov (United States)

Sai Varun, V.; Tejesh, P.; Prashanth, B. N.

2018-02-01

Casting is the best and effective technique used for manufacturing products. The important accessory for casting is furnace. Furnace is used to melt the metal. A perfect furnace is one that reduces the wastage of material, reduces the cost of manufacturing and there by reduces the cost of production. Of all the present day furnaces there may be wastage of material, and the chances of increasing the time of manufacturing as the is continuous need of tilting of the furnace for every mould and then changing the moulds. Considering these aspects, a simple and least expensive tilting rotary furnace is designed and developed. The Tilting and Rotary Furnace consists of mainly melting chamber and the base. The metal enters the melting chamber through the input door that is provided on the top of the melting chamber. Inside the melting chamber there is a graphite furnace. The metal is melted in the graphite crucible. An insulation of ceramic fibre cloth is provided inside the furnace. The metal is melted using Propane gas. The propane gas is easily available and economic. The gas is burned using a pilot burner. The pilot burner is more efficient that other burners. The pilot burner is lit with a push button igniter. The pilot burner is located at the bottom of the combustion chamber. This enables the uniform heating of the metal inside the crucible. The temperature inside the melting chamber is noted using a temperature sensor. The gas input is cut-off if the temperature is exceeding a specific temperature. After the melting of the metal is done the furnace is tilted and after the mould is filled it is rotated. The external gears are used to controlling the tilting. The results of studies carried out for the design & development of low cost, simple furnace that can be mounted anywhere on the shop floor and this can be very much useful for the education purposes and small scale manufacturing. The furnace can be rotated in 360 degrees and can help in reducing the time taken

Comprehensive Numerical Modeling of the Blast Furnace Ironmaking Process

Science.gov (United States)

Zhou, Chenn; Tang, Guangwu; Wang, Jichao; Fu, Dong; Okosun, Tyamo; Silaen, Armin; Wu, Bin

2016-05-01

Blast furnaces are counter-current chemical reactors, widely utilized in the ironmaking industry. Hot reduction gases injected from lower regions of the furnace ascend, reacting with the descending burden. Through this reaction process, iron ore is reduced into liquid iron that is tapped from the furnace hearth. Due to the extremely harsh environment inside the blast furnace, it is difficult to measure or observe internal phenomena during operation. Through the collaboration between steel companies and the Center for Innovation through Visualization and Simulation, multiple computational fluid dynamics (CFD) models have been developed to simulate the complex multiphase reacting flow in the three regions of the furnace, the shaft, the raceway, and the hearth. The models have been used effectively to troubleshoot and optimize blast furnace operations. In addition, the CFD models have been integrated with virtual reality. An interactive virtual blast furnace has been developed for training purpose. This paper summarizes the developments and applications of blast furnace CFD models and the virtual blast furnace.

A comparison of tape-tying versus a tube-holding device for securing endotracheal tubes in adults.

Science.gov (United States)

Murdoch, E; Holdgate, A

2007-10-01

During the transfer of intubated patients, endotracheal tube security is paramount. This study aims to compare two methods of securing an endotracheal tube in adults: tying with a cloth tape versus the Thomas Endotracheal Tube Holder (Laerdal). A manikin-based study was performed using paramedics and critical care doctors (consultants and senior trainees) as participants. Each participant was asked to secure an endotracheal tube that had been placed within the trachea of a manikin a total of six times, the first three times using tied cloth tape and the last three times using a Thomas Endotracheal Tube Holder. Following each 'fixation' and after the participant had left the room, the security of the tube was tested by applying a fixed force laterally and to the right by dropping a 1.25 kg weight a distance of 50 cm. The amount of movement of the tube with respect to the teeth was measured and recorded in millimetres. Two-hundred-and-seventy tube fixations (135 tied vs. 135 tube holder) were performed by 45 participants. The degree of tube movement was significantly higher when the tube was secured with a tie compared with when the tube holder was used (median movement 22 mm vs. 4 mm, P tube holder device minimised tube movement in a manikin model when compared with conventional tape tying. The use of this device when transporting intubated patients may reduce the risk of tube displacement though further clinical studies are warranted.

Thermodynamic Temperatures of High-Temperature Fixed Points: Uncertainties Due to Temperature Drop and Emissivity

Science.gov (United States)

Castro, P.; Machin, G.; Bloembergen, P.; Lowe, D.; Whittam, A.

2014-07-01

This study forms part of the European Metrology Research Programme project implementing the New Kelvin to assign thermodynamic temperatures to a selected set of high-temperature fixed points (HTFPs), Cu, Co-C, Pt-C, and Re-C. A realistic thermal model of these HTFPs, developed in finite volume software ANSYS FLUENT, was constructed to quantify the uncertainty associated with the temperature drop across the back wall of the cell. In addition, the widely applied software package, STEEP3 was used to investigate the influence of cell emissivity. The temperature drop, , relates to the temperature difference due to the net loss of heat from the aperture of the cavity between the back wall of the cavity, viewed by the thermometer, defining the radiance temperature, and the solid-liquid interface of the alloy, defining the transition temperature of the HTFP. The actual value of can be used either as a correction (with associated uncertainty) to thermodynamic temperature evaluations of HTFPs, or as an uncertainty contribution to the overall estimated uncertainty. In addition, the effect of a range of furnace temperature profiles on the temperature drop was calculated and found to be negligible for Cu, Co-C, and Pt-C and small only for Re-C. The effective isothermal emissivity is calculated over the wavelength range from 450 nm to 850 nm for different assumed values of surface emissivity. Even when furnace temperature profiles are taken into account, the estimated emissivities change only slightly from the effective isothermal emissivity of the bare cell. These emissivity calculations are used to estimate the uncertainty in the temperature assignment due to the uncertainty in the emissivity of the blackbody.

Development of vacuum brazing furnace

International Nuclear Information System (INIS)

Singh, Rajvir; Yedle, Kamlesh; Jain, A.K.

2005-01-01

In joining of components where welding process is not possible brazing processes are employed. Value added components, high quality RF systems, UHV components of high energy accelerators, carbide tools etc. are produced using different types of brazing methods. Furnace brazing under vacuum atmosphere is the most popular and well accepted method for production of the above mentioned components and systems. For carrying out vacuum brazing successfully it is essential to have a vacuum brazing furnace with latest features of modern vacuum brazing technology. A vacuum brazing furnace has been developed and installed for carrying out brazing of components of copper, stainless steel and components made of dissimilar metals/materials. The above furnace has been designed to accommodate jobs of 700mm diameter x 2000mm long sizes with job weight of 500kgs up to a maximum temperature of 1250 degC at a vacuum of 5 x 10 -5 Torr. Oil diffusion pumping system with a combination of rotary and mechanical booster pump have been employed for obtaining vacuum. Molybdenum heating elements, radiation shield of molybdenum and Stainless Steel Grade 304 have been used. The above furnace is computer controlled with manual over ride facility. PLC and Pentium PC are integrated together to maneuver steps of operation and safety interlocks of the system. Closed loop water supply provides cooling to the system. The installation of the above system is in final stage of completion and it will be ready for use in next few months time. This paper presents insights of design and fabrication of a modern vacuum brazing furnace and its sub-system. (author)

Cleaning of a copper matte smelting slag from a water-jacket furnace by direct reduction of heavy metals.

Science.gov (United States)

Maweja, Kasonde; Mukongo, Tshikele; Mutombo, Ilunga

2009-05-30

Cleaning experiments of a copper matte smelting slag from the water-jacket furnace was undertaken by direct reduction in a laboratory-scale electric furnace. The effects of coal-to-slag ratio, w, and the reduction time, t, were considered for two different coal/slag mixing procedures. In the first procedure, metallurgical coal was added to the molten slag, whereas in the second procedure, coal was premixed with the solid slag before charging into the furnace. The recovery of heavy metals (Cu, Co), and the fuming of Pb and Zn were investigated. Contamination of the metal phase by iron and the acidity index of the final slag were analysed as these may impede the economical viability of the process. The lower w value of 2.56% yielded a recovery rate of less than 60% for copper and less than 50% for cobalt, and around 70% for zinc. However, increasing w to 5% allowed the recovery of 70-90% for Cu, Co and Zn simultaneously after 30-60 min reduction of the molten slag. After reduction, the cleaned slags contained only small amounts of copper and cobalt (zinc was efficient as the %Pb of the residual slag dropped to levels lower than 0.04% after 30 min of reduction. Ninety percent of the lead was removed from the initial slag and collected in the dusts. The zinc content of the cleaned slags quickly dropped to between 1 and 3 wt% from the initial 8.2% after 30 min reduction for w value of 5 and after 60 min reduction for w value of 2.56. The dusts contained about 60% Zn and 10% Pb. Recovery of lead from fuming of the slag was higher than 90% in all the experimental conditions considered in this study.

Emission spectroscopy for coal-fired cyclone furnace diagnostics

Energy Technology Data Exchange (ETDEWEB)

Wehrmeyer, J.A.; Boll, D.E.; Smith, R. [Vanderbilt University, Nashville, TN (United States). Dept. of Mechanical Engineering

2003-08-01

Using a spectrograph and charge-coupled device (CCD) camera, ultraviolet and visible light emission spectra were obtained from a coal-burning electric utility's cyclone furnaces operating at either fuel-rich or fuel-lean conditions. The aim of this effort is to identify light emission signals that can be related to a cyclone furnace's operating condition in order to adjust its air/fuel ratio to minimize pollutant production. Emission spectra at the burner and outlet ends of cyclone furnaces were obtained. Spectra from all cyclone burners show emission lines for the trace elements Li, Na, K, and Rb, as well as the molecular species OH and CaOH. The Ca emission line is detected at the burner end of both the fuel-rich and fuellean cyclone furnaces but is not detected at the outlet ends of either furnace type. Along with the disappearance of Ca is a concomitant increase in the CaOH signal at the outlet end of both types of furnaces. The OH signal strength is in general stronger when viewing at the burner end rather than the exhaust end of both the fuel-rich and fuel-lean cyclone furnaces, probably due to high, non-equilibrium amounts of OH present inside the furnace. Only one molecular species was detected that could be used as a measure of air/fuel ratio: MgOH. It was detected at the burner end of fuel-rich cyclone furnaces but not detected in fuel-lean cyclone furnaces. More direct markers of air/fuel ratio, such as CO and 02 emission, were not detected, probably due to the generally weak nature of molecular emission relative to ambient blackbody emission present in the cyclone furnaces, even at ultraviolet wavelengths.

AUTOMATION OF GLASS TEMPERING FURNACE BY USING PLC

Directory of Open Access Journals (Sweden)

Abdullah BÜYÜKYILDIZ

2007-02-01

Full Text Available In this study, a furnace which is used for observation of environments under high temperature, and also used for manufacturing of glasses which are resisted to high temperature has been designed and implemented. Automation of this system has been done by using PLC. Operating parameters of furnace such as materials entering, the furnace, the local temperature control of furnace, cooling control and materials outing have been sensed with Hall Effect Sensor. Furthermore, the observation of parameters of furnace on screen has been provided with SCADA software. Obtained products have been shown the system works successfully.

Thermostatic tissue platform for intravital microscopy: 'the hanging drop' model.

Science.gov (United States)

Pavlovic, Dragan; Frieling, Helge; Lauer, Kai-Stephan; Bac, Vo Hoai; Richter, Joern; Wendt, Michael; Lehmann, Christian; Usichenko, Taras; Meissner, Konrad; Gruendling, Matthias

2006-11-01

Intravital microscopy imposes the particular problem of the combined control of the body temperature of the animal and the local temperature of the observed organ or tissues. We constructed and tested, in the rat ileum microcirculation preparation, a new organ-support platform. The platform consisted of an organ bath filled with physiological solution, and contained a suction tube, a superfusion tube, an intestine-support hand that was attached to a micromanipulator and a thermometer probe. To cover the intestine we used a cover glass plate with a plastic ring glued on its upper surface. After a routine procedure (anaesthesia, monitoring and surgery), the intestine segment (2-3 cm long) was gently exteriorized and placed on the 'hand' of the organ support. A small part of the intestine formed a small 'island' in the bath that was filled with physiological salt solution. The cover glass was secured in place. The physiological salt solution from the superfusion tube, which was pointed to the lower surface of the cover glass, formed a 'hanging drop'. The objective of the microscope was then immersed into distilled water that was formed by the cover glass plastic ring. The 'hanging drop' technique prevented any tissue quenching, ensured undisturbed microcirculation, provided for stable temperature and humidity, and permitted a clear visual field.

A cylindrical furnace for absorption spectral studies

Indian Academy of Sciences (India)

A cylindrical furnace with three heating zones, capable of providing a temperature of 1100°C, has been fabricated to enable recording of absorption spectra of high temperature species. The temperature of the furnace can be controlled to ± 1°C of the set temperature. The salient feature of this furnace is that the material ...

Pressure drop and friction factor correlations of supercritical flow

International Nuclear Information System (INIS)

Fang Xiande; Xu Yu; Su Xianghui; Shi Rongrong

2012-01-01

Highlights: ► Survey and evaluation of friction factor models for supercritical flow. ► Survey of experimental study of supercritical flow. ► New correlation of friction factor for supercritical flow. - Abstract: The determination of the in-tube friction pressure drop under supercritical conditions is important to the design, analysis and simulation of transcritical cycles of air conditioning and heat pump systems, nuclear reactor cooling systems and some other systems. A number of correlations for supercritical friction factors have been proposed. Their accuracy and applicability should be examined. This paper provides a comprehensive survey of experimental investigations into the pressure drop of supercritical flow in the past decade and a comparative study of supercritical friction factor correlations. Our analysis shows that none of the existing correlations is completely satisfactory, that there are contradictions between the existing experimental results and thus more elaborate experiments are needed, and that the tube roughness should be considered. A new friction factor correlation for supercritical tube flow is proposed based on 390 experimental data from the available literature, including 263 data of supercritical R410A cooling, 45 data of supercritical R404A cooling, 64 data of supercritical carbon dioxide (CO 2 ) cooling and 18 data of supercritical R22 heating. Compared with the best existing model, the new correlation increases the accuracy by more than 10%.

Silva. EDF two-phase 1D annular model of a CFB boiler furnace

Energy Technology Data Exchange (ETDEWEB)

Montat, D.; Fauquet, Ph. [Electricite de France (EDF), 78 - Chatou (France). Researckh and Development Div.; Lafanechere, L.; Bursi, J.M. [Electricite de France (EDF) (France). Construction Div.

1997-01-01

SILVA computer code is used for the modelling of the thermal-hydraulics and of the combustion of a coal-fired CFBC solid loop. In a first step, only the furnace is considered. The model is based on a 1D annular two phases description of the hydrodynamics. The model is based on particle mass balances and pressure drop calculations. A basic combustion model is incorporated into this model. The coal combustion is divided in two phases, the combustion of volatile matter and the heterogeneous combustion. The model has been developed within LEGO software and can be included into the global model of the solid loop developed by EDF. (author) 26 refs.

Modeling and Simulation of Claus Unit Reaction Furnace

Directory of Open Access Journals (Sweden)

Maryam Pahlavan

2016-01-01

Full Text Available Reaction furnace is the most important part of the Claus sulfur recovery unit and its performance has a significant impact on the process efficiency. Too many reactions happen in the furnace and their kinetics and mechanisms are not completely understood; therefore, modeling reaction furnace is difficult and several works have been carried out on in this regard so far. Equilibrium models are commonly used to simulate the furnace, but the related literature states that the outlet of furnace is not in equilibrium and the furnace reactions are controlled by kinetic laws; therefore, in this study, the reaction furnace is simulated by a kinetic model. The predicted outlet temperature and concentrations by this model are compared with experimental data published in the literature and the data obtained by PROMAX V2.0 simulator. The results show that the accuracy of the proposed kinetic model and PROMAX simulator is almost similar, but the kinetic model used in this paper has two importance abilities. Firstly, it is a distributed model and can be used to obtain the temperature and concentration profiles along the furnace. Secondly, it is a dynamic model and can be used for analyzing the transient behavior and designing the control system.

An update on blast furnace granular coal injection

Energy Technology Data Exchange (ETDEWEB)

Hill, D.G. [Bethlehem Steel Corp., Burns Harbor, IN (United States); Strayer, T.J.; Bouman, R.W. [Bethlehem Steel Corp., PA (United States)

1997-12-31

A blast furnace coal injection system has been constructed and is being used on the furnace at the Burns Harbor Division of Bethlehem Steel. The injection system was designed to deliver both granular (coarse) and pulverized (fine) coal. Construction was completed on schedule in early 1995. Coal injection rates on the two Burns Harbor furnaces were increased throughout 1995 and was over 200 lbs/ton on C furnace in September. The injection rate on C furnace reached 270 lbs/ton by mid-1996. A comparison of high volatile and low volatile coals as injectants shows that low volatile coal replaces more coke and results in a better blast furnace operation. The replacement ratio with low volatile coal is 0.96 lbs coke per pound of coal. A major conclusion of the work to date is that granular coal injection performs very well in large blast furnaces. Future testing will include a processed sub-bituminous coal, a high ash coal and a direct comparison of granular versus pulverized coal injection.

Insights from the pollination drop proteome and the ovule transcriptome of Cephalotaxus at the time of pollination drop production.

Science.gov (United States)

Pirone-Davies, Cary; Prior, Natalie; von Aderkas, Patrick; Smith, Derek; Hardie, Darryl; Friedman, William E; Mathews, Sarah

2016-05-01

Many gymnosperms produce an ovular secretion, the pollination drop, during reproduction. The drops serve as a landing site for pollen, but also contain a suite of ions and organic compounds, including proteins, that suggests diverse roles for the drop during pollination. Proteins in the drops of species of Chamaecyparis, Juniperus, Taxus, Pseudotsuga, Ephedra and Welwitschia are thought to function in the conversion of sugars, defence against pathogens, and pollen growth and development. To better understand gymnosperm pollination biology, the pollination drop proteomes of pollination drops from two species of Cephalotaxus have been characterized and an ovular transcriptome for C. sinensis has been assembled. Mass spectrometry was used to identify proteins in the pollination drops of Cephalotaxus sinensis and C. koreana RNA-sequencing (RNA-Seq) was employed to assemble a transcriptome and identify transcripts present in the ovules of C. sinensis at the time of pollination drop production. About 30 proteins were detected in the pollination drops of both species. Many of these have been detected in the drops of other gymnosperms and probably function in defence, polysaccharide metabolism and pollen tube growth. Other proteins appear to be unique to Cephalotaxus, and their putative functions include starch and callose degradation, among others. Together, the proteins appear either to have been secreted into the drop or to occur there due to breakdown of ovular cells during drop production. Ovular transcripts represent a wide range of gene ontology categories, and some may be involved in drop formation, ovule development and pollen-ovule interactions. The proteome of Cephalotaxus pollination drops shares a number of components with those of other conifers and gnetophytes, including proteins for defence such as chitinases and for carbohydrate modification such as β-galactosidase. Proteins likely to be of intracellular origin, however, form a larger component of drops

Design of a rotating-hearth furnace

Energy Technology Data Exchange (ETDEWEB)

Behrens, H A [Verein Deutscher Eisenhuettenleute (VDEh), Duesseldorf (Germany, F.R.)

1979-10-01

Presented in two parts, this paper is intended to provide an outline of the theoretical fundamentals for the design of rotating-hearth furnaces for heating round stock and deals with the characteristic design features of such furnaces.

Optimization of a Finned Shell and Tube Heat Exchanger Using a Multi-Objective Optimization Genetic Algorithm

Directory of Open Access Journals (Sweden)

Heidar Sadeghzadeh

2015-08-01

Full Text Available Heat transfer rate and cost significantly affect designs of shell and tube heat exchangers. From the viewpoint of engineering, an optimum design is obtained via maximum heat transfer rate and minimum cost. Here, an analysis of a radial, finned, shell and tube heat exchanger is carried out, considering nine design parameters: tube arrangement, tube diameter, tube pitch, tube length, number of tubes, fin height, fin thickness, baffle spacing ratio and number of fins per unit length of tube. The “Delaware modified” technique is used to determine heat transfer coefficients and the shell-side pressure drop. In this technique, the baffle cut is 20 percent and the baffle ratio limits range from 0.2 to 0.4. The optimization of the objective functions (maximum heat transfer rate and minimum total cost is performed using a non-dominated sorting genetic algorithm (NSGA-II, and compared against a one-objective algorithm, to find the best solutions. The results are depicted as a set of solutions on a Pareto front, and show that the heat transfer rate ranges from 3517 to 7075 kW. Also, the minimum and maximum objective functions are specified, allowing the designer to select the best points among these solutions based on requirements. Additionally, variations of shell-side pressure drop with total cost are depicted, and indicate that the pressure drop ranges from 3.8 to 46.7 kPa.

Glass: Rotary Electric Glass Furnace

Energy Technology Data Exchange (ETDEWEB)

Recca, L.

1999-01-29

Compared to conventional gas-fired furnaces, the new rotary electric furnace will increase energy efficiency while significantly reducing air emissions, product turnaround time, and labor costs. As this informative new fact sheet explains, the thousand different types of glass optical blanks produced for the photonics industry are used for lasers, telescopes, cameras, lights, and many other products.

Paired Straight Hearth Furnace - Transformational Ironmaking Process

Energy Technology Data Exchange (ETDEWEB)

Lu, Wei-Kao [McMaster Univ., Hamilton, ON (Canada); Debski, Paul [Andritz Metals Inc.,Canonsburg, PA (United States)

2014-11-19

The U. S. steel industry has reduced its energy intensity per ton of steel shipped by 33% since 1990. However, further significant gains in energy efficiency will require the development of new, transformational iron and steelmaking processes. The Paired Straight Hearth Furnace (PSH) process is an emerging alternative high productivity, direct reduced iron (DRI) technology that may achieve very low fuel rates and has the potential to replace blast furnace ironmaking. The PSH furnace can operate independently or may be coupled with other melting technologies to produce liquid hot metal that is both similar to blast furnace iron and suitable as a feedstock for basic oxygen steelmaking furnaces. The PSH process uses non-metallurgical coal as a reductant to convert iron oxides such as iron ore and steelmaking by-product oxides to DRI pellets. In this process, a multi-layer, nominally 120mm tall bed of composite “green balls” made from oxide, coal and binder is built up and contained within a moving refractory hearth. The pellet bed absorbs radiant heat energy during exposure to the high temperature interior refractory surfaces of the PSH while generating a strongly reducing gas atmosphere in the bed that yields a highly metalized DRI product. The PSH concept has been well tested in static hearth experiments. A moving bed design is being developed. The process developers believe that if successful, the PSH process has the potential to replace blast furnaces and coke ovens at a fraction of the operating and capital cost while using about 30% less energy relative to current blast furnace technology. DRI output could also feed electric arc furnaces (EAFs) by displacing a portion of the scrap charge.

Industrial furnace with improved heat transfer

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, M.; Lingle, T.M.

1993-07-20

A method is described for effecting improved heat transfer with in an industrial furnace having a cylindrical furnace section, a door at one end of the furnace section, an end plate at the opposite end of the section a circular fan plate concentrically positioned within the furnace section to define a cylindrical fan chamber between the plate and the end section with a fan there between and a heat treat chamber between the plate and the door, the fan plate defining a non-orificing annular space extending between the interior of the cylindrical furnace section and the outer edge of the plate, the plate having a centrally located under-pressure opening extending there through and a plurality of circumferentially spaced tubular heating elements extending through the annular space into the heat treating chamber, the method comprising the steps of: (a) heating the heating elements to a temperature which is hotter that the temperature of the work within the heat treating chamber; (b) rotating the fan at a speed sufficient to form a portion of the furnace atmosphere as a wind mass swirling about the fan chamber; (c) propagating the wind mass through the annular space into the heat treating chamber as a swirling wind mass in the form of an annulus, the wind mass impinging the heating elements to establish heat transfer contact therewith while the mass retains its annulus shape until contacting the door and without any significant movement of the wind mass into the center of the heat treating chamber; (d) drawing the wind mass through the under-pressure zone after the wind mass comes into heat transfer contact with the work in the heat treating chamber; and (e) thereafter heating the work by radiation from the beating elements at high furnace temperatures in excess of about 1,600 F.

Cold experiments on ligament formation for blast furnace slag granulation

International Nuclear Information System (INIS)

Liu Junxiang; Yu Qingbo; Li Peng; Du Wenya

2012-01-01

Rotary cup atomization for molten slag granulation is an attractive alternative to water quenching. However, the mechanism of disintegration of molten slag must be assessed. In the present study, a glycerol/water mixture was substituted for molten slag, and the mechanism of ligament formation in a rotary cup was investigated using photos taken by a high-speed camera. The effects of the angular speed and inner depth of the rotary cup on ligament disintegration was investigated. The results showed that one state of disintegration may transform into another state as the angular speed of the rotary cup increases at a given liquid flow rate. During ligament formation, the number of ligaments increased with an increase in the angular speed of the rotary cup, and a decrease in the diameter of ligament and liquid drop was observed. Moreover, the initial point of disintegration of the ligament moved to the lip of the rotary cup as the angular speed increased. An equation describing the relationship between the diameter of the liquid drop and various factors was used to predict the diameter of the liquid drop. A rotary cup with an inner depth of 30 mm was the best choice for granulation. The results of the present study will be useful for designing devices used in molten slag granulation. - Highlights: ►The results can be used in the granulation of molten blast furnace slag. ► The three different states of disintegration occur as the angular speed of rotary cup increases. ► The mechanism of ligament disintegration is analyzed. ► Eq. can be used to predict the diameter of liquid drop. ► A rotary cup with an inner depth of 30 mm is optimal for granulation.

Optical cavity furnace for semiconductor wafer processing

Science.gov (United States)

Sopori, Bhushan L.

2014-08-05

An optical cavity furnace 10 having multiple optical energy sources 12 associated with an optical cavity 18 of the furnace. The multiple optical energy sources 12 may be lamps or other devices suitable for producing an appropriate level of optical energy. The optical cavity furnace 10 may also include one or more reflectors 14 and one or more walls 16 associated with the optical energy sources 12 such that the reflectors 14 and walls 16 define the optical cavity 18. The walls 16 may have any desired configuration or shape to enhance operation of the furnace as an optical cavity 18. The optical energy sources 12 may be positioned at any location with respect to the reflectors 14 and walls defining the optical cavity. The optical cavity furnace 10 may further include a semiconductor wafer transport system 22 for transporting one or more semiconductor wafers 20 through the optical cavity.

Investigation of using shrinking method in construction of Institute for Research in Fundamental Sciences Electron Linear Accelerator TW-tube (IPM TW-Linac tube)

Science.gov (United States)

Ghasemi, F.; Abbasi Davani, F.

2015-06-01

Due to Iran's growing need for accelerators in various applications, IPM's electron Linac project has been defined. This accelerator is a 15 MeV energy S-band traveling-wave accelerator which is being designed and constructed based on the klystron that has been built in Iran. Based on the design, operating mode is π /2 and the accelerating chamber consists of two 60cm long tubes with constant impedance and a 30cm long buncher. Amongst all construction methods, shrinking method is selected for construction of IPM's electron Linac tube because it has a simple procedure and there is no need for large vacuum or hydrogen furnaces. In this paper, different aspects of this method are investigated. According to the calculations, linear ratio of frequency alteration to radius change is 787.8 MHz/cm, and the maximum deformation at the tube wall where disks and the tube make contact is 2.7μ m. Applying shrinking method for construction of 8- and 24-cavity tubes results in satisfactory frequency and quality factor. Average deviations of cavities frequency of 8- and 24-cavity tubes to the design values are 0.68 MHz and 1.8 MHz respectively before tune and 0.2 MHz and 0.4 MHz after tune. Accelerating tubes, buncher, and high power couplers of IPM's electron linac are constructed using shrinking method.

Numerical simulation of tubes-in-tube heat exchanger in a mixed refrigerant Joule-Thomson cryocooler

Science.gov (United States)

Damle, R. M.; Ardhapurkar, P. M.; Atrey, M. D.

2017-02-01

Mixed refrigerant Joule-Thomson (MRJT) cryocoolers can produce cryogenic temperatures with high efficiency and low operating pressures. As compared to the high system pressures of around 150-200 bar with nitrogen, the operational pressures with non-azeotropic mixtures (e.g., nitrogen-hydrocarbons) come down to 10-25 bar. With mixtures, the heat transfer in the recuperative heat exchanger takes place in the two-phase region. The simultaneous boiling and condensation of the cold and hot gas streams lead to higher heat transfer coefficients as compared to single phase heat exchange. The two-phase heat transfer in the recuperative heat exchanger drastically affects the performance of a MRJT cryocooler. In this work, a previously reported numerical model for a simple tube-in-tube heat exchanger is extended to a multi tubes-in-tube heat exchanger with a transient formulation. Additionally, the J-T expansion process is also considered to simulate the cooling process of the heat exchanger from ambient temperature conditions. A tubes-in-tube heat exchanger offers more heat transfer area per unit volume resulting in a compact design. Also, the division of flow in multiple tubes reduces the pressure drop in the heat exchanger. Simulations with different mixtures of nitrogen-hydrocarbons are carried out and the numerical results are compared with the experimental data.

Vaporization inside a mini microfin tube: experimental results and modeling

Science.gov (United States)

Diani, A.; Rossetto, L.

2015-11-01

This paper proposes a comparison among the common R134a and the extremely low GWP refrigerant R1234yf during vaporization inside a mini microfin tube. This microfin tube has an internal diameter of 2.4 mm, it has 40 fins, with a fin height of 0.12 mm. Due to the high heat transfer coefficients shown by this tube, this technology can lead to a refrigerant charge reduction. Tests were run in the Heat Transfer in Micro Geometries Lab of the Dipartimento di Ingegneria Industriale of the Università di Padova. Mass velocities range between 375 and 940 kg m-2 s-1, heat fluxes from 10 to 50 kW m-2, vapour qualities from 0.10 to 0.99, at a saturation temperature of 30°C. The comparison among the two fluids is proposed at the same operating conditions, in order to highlight the heat transfer and pressure drop differences among the two refrigerants. In addition, two correlations are proposed to estimate the heat transfer coefficient and frictional pressure drop during refrigerant flow boiling inside mini microfin tubes. These correlations well predict the experimental values, and thus they can be used as a useful tool to design evaporators based on these mini microfin tubes.

Transfer coefficients for plate fin and elliptical tube heat exchangers

International Nuclear Information System (INIS)

Saboya, S.M.; Saboya, F.E.M.

1981-01-01

In order to determine transfer coefficients for plate fin and elliptical tube exchangers, mass transfer experiments have been performed using the naphthalene sublimation technique. By means of the heat-mass transfer analogy, the results can be converted to heat transfer results. The transfer coefficients were compared with those for circular tube exchangers and the comparison revealed no major differences. This is a positive outcome, since the use of elliptical tubes may reduce substantially the pressure drop, without affecting the transfer characteristics.(Author) [pt

Mass Balance Modeling for Electric Arc Furnace and Ladle Furnace System in Steelmaking Facility in Turkey

Institute of Scientific and Technical Information of China (English)

(I)smail Ekmek(c)i; Ya(s)ar Yetisken; (U)nal (C)amdali

2007-01-01

In the electric arc furnace (EAF) steel production processes, scrap steel is principally used as a raw material instead of iron ore. In the steelmaking process with EAF, scrap is first melted in the furnace and then the desired chemical composition of the steel can be obtained in a special furnace such as ladle furnace (LF). This kind of furnace process is used for the secondary refining of alloy steel. LF furnace offers strong heating fluxes and enables precise temperature control, thereby allowing for the addition of desired amounts of various alloying elements. It also provides outstanding desulfurization at high-temperature treatment by reducing molten steel fluxes and removing deoxidation products. Elemental analysis with mass balance modeling is important to know the precise amount of required alloys for the LF input with respect to scrap composition. In present study, chemical reactions with mass conservation law in EAF and LF were modeled altogether as a whole system and chemical compositions of the final steel alloy output can be obtained precisely according to different scrap compositions, alloying elements ratios, and other input amounts. Besides, it was found that the mass efficiency for iron element in the system is 95.93%. These efficiencies are calculated for all input elements as 8.45% for C, 30.31% for Si, 46.36% for Mn, 30.64% for P, 41.96% for S, and 69.79% for Cr, etc. These efficiencies provide valuable ideas about the amount of the input materials that are vanished or combusted for 100 kg of each of the input materials in the EAF and LF system.

Model of Draining of the Blast Furnace Hearth with an Impermeable Zone

Science.gov (United States)

Saxén, Henrik

2015-02-01

Due to demands of lower costs and higher productivity in the steel industry, the volume of operating blast furnaces has grown during the last decades. As the height is limited by the allowable pressure drop, the hearth diameter has grown considerably and, along with this, also draining-related problems. In this paper a mathematical model is developed for simulating the drainage in the case where an impermeable region exists in the blast furnace hearth. The model describes the quasi-stationary drainage process of a hearth with two operating tapholes, where the communication between the two pools of molten slag and iron can be controlled by parameterized expressions. The model also considers the case where the buoyancy of the liquids is sufficient for lifting the coke bed. The implications of different size of the liquid pools, communication between the pools, bed porosity, etc. are studied by simulation, and conclusions concerning their effect on the drainage behavior and evolution of the liquid levels in the hearth are drawn. The simulated liquid levels are finally demonstrated to give rise to a pressure profile acting on the hearth which agrees qualitatively with signals from strain gauges mounted in the hearth wall of an industrial ironmaking process.

Shell and Double Concentric Tube Heat Exchanger Calculations and Analysis

Directory of Open Access Journals (Sweden)

Basma Abbas Abdulmajeed

2015-01-01

Full Text Available This study concerns a new type of heat exchangers, which is that of shell-and-double concentric tube heat exchangers. The case studies include both design calculations and performance calculations. The new heat exchanger design was conducted according to Kern method. The volumetric flow rates were 3.6 m3/h and 7.63 m3/h for the hot oil and water respectively. The experimental parameters studied were: temperature, flow rate of hot oil, flow rate of cold water and pressure drop. A comparison was made for the theoretical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (- 1.6%. The percentage errors for the pressure drop in the shell and in the concentric tubes were (17.2% and (- 39% respectively. For cold water outlet temperature, the percentage error was (- 3.3%, while it was (18% considering the pressure drop in the annulus formed. The percentage error for the total power consumed was (-10.8% A theoretical comparison was made between the new design and the conventional heat exchanger from the point of view of, length, mass, pressure drop and total power consumed.

Final Report, Materials for Industrial Heat Recovery Systems, Task 1 Improved Materials and Operation of Recuperators for Aluminum Melting Furnaces

Energy Technology Data Exchange (ETDEWEB)

Keiser, James R.; Sarma, Gorti B.; Thekdi, Arvind; Meisner Roberta A.; Phelps, Tony; Willoughby, Adam W.; Gorog, J. Peter; Zeh, John; Ningileri, Shridas; Liu, Yansheng; Xiao, Chenghe

2007-09-30

Production of aluminum is a very energy intensive process which is increasingly more important in the USA. This project concentrated on the materials issues associated with recovery of energy from the flue gas stream in the secondary industry where scrap and recycled metal are melted in large furnaces using gas fired burners. Recuperators are one method used to transfer heat from the flue gas to the air intended for use in the gas burners. By preheating this combustion air, less fuel has to be used to raise the gas temperature to the desired level. Recuperators have been successfully used to preheat the air, however, in many cases the metallic recuperator tubes have a relatively limited lifetime – 6 to 9 months. The intent of this project was to determine the cause of the rapid tube degradation and then to recommend alternative materials or operating conditions to prolong life of the recuperator tubes. The first step to understanding degradation of the tubes was to examine exposed tubes to identify the corrosion products. Analyses of the surface scales showed primarily iron oxides rather than chromium oxide suggesting the tubes were probably cycled to relatively high temperatures to the extent that cycling and subsequent oxide spalling reduced the surface concentration of chromium below a critical level. To characterize the temperatures reached by the tubes, thermocouples were mounted on selected tubes and the temperatures measured. During the several hour furnace cycle, tube temperatures well above 1000°C were regularly recorded and, on some occasions, temperatures of more than 1100°C were measured. Further temperature characterization was done with an infrared camera, and this camera clearly showed the variations in temperature across the first row of tubes in the four recuperator modules. Computational fluid dynamics was used to model the flow of combustion air in the tubes and the flue gas around the outside of the tubes. This modeling showed the

R245fa Flow Boiling inside a 4.2 mm ID Microfin Tube

Science.gov (United States)

Longo, G. A.; Mancin, S.; Righetti, G.; Zilio, C.

2017-11-01

This paper presents the R245fa flow boiling heat transfer and pressure drop measurements inside a mini microfin tube with internal diameter at the fin tip of 4.2 mm, having 40 fins, 0.15 mm high with a helix angle of 18°. The tube was brazed inside a copper plate and electrically heated from the bottom. Sixteen T-type thermocouples are located in the copper plate to monitor the wall temperature. The experimental measurements were carried out at constant mean saturation temperature of 30 °C, by varying the refrigerant mass velocity between 100 kg m-2 s-1 and 300 kg m-2 s-1, the vapour quality from 0.15 to 0.95, at two different heat fluxes: 30 and 60 kW m-2. The experimental results are presented in terms of two-phase heat transfer coefficient, onset dryout vapour quality, and frictional pressure drop. Moreover, the experimental measurements are compared against the most updated models for boiling heat transfer coefficient and frictional pressure drop estimations available in the open literature for microfin tubes.

Simulation and analysis of the thermal and deformation behaviour of `as-received` and `hydrided` pressure tubes used in the circumferential temperature distribution experiments (end of life/pressure tube behaviour)

Energy Technology Data Exchange (ETDEWEB)

Muir, W C; Bayoumi, M H [Ontario Hydro, Toronto, ON (Canada)

1996-12-31

It is postulated that in-reactor pressure tubes may be subjected to radiation damage and dissolved deuterium which could change the pressure tube characteristics and lead to different behaviour than that of as-received pressure tubes under large LOCA (loss of coolant) conditions. A hydrided pressure tube was used to study the effect of dissolved hydrogen on thermal-mechanical behaviour. In the experiment, simulating an in-reactor (hydrided) pressure tube with circumferential differential temperature under boil-off conditions, the pressure tube ballooned into contact with the calandria tube. The pressure tube used in this experiment was hydrided in a furnace to a nominal value of 200 {mu}g/g dissolved hydrogen. This test was a repeat of the first supplementary boil-off test (S-5-1) which used an as-received pressure tube. The objective of this paper is to analyze the results obtained from the simulation of this Boil-Off test using the SMARTT computer code and to examine the effect of hydriding on the thermal and ballooning behaviour of the pressure tube by comparison with the results obtained from test S-5-1. A discussion of the results obtained from this comparison is presented together with an analysis of their application to the analysis of pressure tube behaviour in CANDU reactors. (author). 13 refs., 1 tab., 16 figs.

Simulation and analysis of the thermal and deformation behaviour of 'as-received' and 'hydrided' pressure tubes used in the circumferential temperature distribution experiments (end of life/pressure tube behaviour)

International Nuclear Information System (INIS)

Muir, W.C.; Bayoumi, M.H.

1995-01-01

It is postulated that in-reactor pressure tubes may be subjected to radiation damage and dissolved deuterium which could change the pressure tube characteristics and lead to different behaviour than that of as-received pressure tubes under large LOCA (loss of coolant) conditions. A hydrided pressure tube was used to study the effect of dissolved hydrogen on thermal-mechanical behaviour. In the experiment, simulating an in-reactor (hydrided) pressure tube with circumferential differential temperature under boil-off conditions, the pressure tube ballooned into contact with the calandria tube. The pressure tube used in this experiment was hydrided in a furnace to a nominal value of 200 μg/g dissolved hydrogen. This test was a repeat of the first supplementary boil-off test (S-5-1) which used an as-received pressure tube. The objective of this paper is to analyze the results obtained from the simulation of this Boil-Off test using the SMARTT computer code and to examine the effect of hydriding on the thermal and ballooning behaviour of the pressure tube by comparison with the results obtained from test S-5-1. A discussion of the results obtained from this comparison is presented together with an analysis of their application to the analysis of pressure tube behaviour in CANDU reactors. (author). 13 refs., 1 tab., 16 figs

Hydraulic design considerations for a multi-tube sodium economizer

International Nuclear Information System (INIS)

Hassberger, J.A.; McConnell, P.M.; Olson, W.H.

1975-01-01

Operating experience gained from tests shows that flow distribution effects can severely affect the thermal performance of high effectiveness, low pressure drop sodium heat exchangers. It has been shown that design efforts for such devices must include proper consideration of potential causes of flow maldistribution within the tube bundle. Furthermore, it has been demonstrated that fairly simple design features can be capable of eliminating detrimental flow fields in the tube bundle

Alternative fuels for multiple-hearth furnaces

Energy Technology Data Exchange (ETDEWEB)

Bracket, B D; Lawson, T U

1980-04-01

Results are described of a feasibility study on the use of refuse-derived fuel, shredded paper, wood waste, coal, and waste oil in multiple-hearth furnaces at the Lower Molonglo Water Quality Control Centre in Australia. An assessment of waste fuel availability and characteristics is given, and a summary is made of the technical and economic aspects of using these alternative fuels and of minimizing furnace fuel requirements by reducing sludge moisture. The recommended method of reducing fuel oil consumption in the furnace is shown to be sludge drying, using process exhaust heat in a rotary dryer.

Estimation of slagging in furnaces; Kuonaavuuden ennustaminen kivihiilen poelypoltossa

Energy Technology Data Exchange (ETDEWEB)

Jacobson, T; Jaeaeskelaeinen, K; Oeini, J; Koskiahde, A; Jokiniemi, J; Pyykkoenen, J [Imatran Voima Oy, Vantaa (Finland)

1997-10-01

Understanding and estimation of slagging in furnaces is essential in the design of new power plants with high steam values or in modifications like low-NO{sub x} retrofits in existing furnaces. Major slagging yields poor efficiency, difficult operation and high maintenance costs of the plant. The aim of the project is to develop a computational model for slagging in pulverized coal combustion. The model is based on Computer Controlled Scanning Electron Microscopy (CCSEM) analysis of mineral composition of the coal and physical models for behaviour of minerals inside a furnace. The analyzed mineral particles are classified to five composition classes and distributed to calculational coal particles if internal minerals of coal. The calculational coal particles and the external minerals are traced in the furnace to find out the behaviour of minerals inside the furnace. If the particle tracing indicates that the particle hits the heat transfer surface of the furnace the viscosity of the particle is determined to see if particle is sticky. The model will be implemented to 3D computational fluid dynamics based furnace simulation environment Ardemus which predicts the fluid dynamics, heat transfer and combustion in a furnace. (orig.)

Dynamics and control of a gas-fired furnace

NARCIS (Netherlands)

Roffel, B.; Rijnsdorp, J.E.

1974-01-01

A non-linear model has been developed for a gas-fired furnace in which oil is heated. The model is applicable from minimum to maximum heat load of the furnace. The dynamics of the model have been compared to experimental results, which were obtained for a pilot-scale furnace. They are in good

Measurement of the Velocity and Pressure Drop in a Tubular Type Fuel

International Nuclear Information System (INIS)

Jonghark Park; Heetaek Chae; Cheol Park; Heonil Kim

2006-01-01

We have developed a tubular type fuel assembly design as one of candidates for fuel to be used in the Advanced HANARO Reactor (AHR). The tubular type fuel has several merits over a rod type fuel with respect to the thermal-hydraulic and structural safety; the larger ratio of surface area to volume makes the surface temperature of a fuel element become lower, and curved plate is stronger against longitudinal bending and vibration. In the other side, a disadvantage is expected such that the flow velocity can be distributed unevenly channel by channel because the flow channels are isolated from each other in a tubular type fuel assembly. In addition to the design development, we also investigated the flow characteristics of the tubular fuel experimentally. To examine the flow velocity distribution and pressure drop, we made an experiment facility and a mockup of the tubular fuel assembly. The fuel assembly consists of 6 concentric fuel tubes so that 7 layers are made between fuel tubes. Since each layer is divided into three sections by stiffeners, 21 isolated flow channels are made in total. We employed pitot-tubes to measure the coolant velocity in each channel. The maximum velocity was measured as large as about 28% of the average velocity. It was observed in the innermost channel contrarily to the expectation from the hydraulic diameter. A change in the total flow rate did not affect the flow distribution. Meanwhile, the pressure drop was measured as about 70% of the drop in the rod type fuel assembly in use in HANARO. (authors)

Electrohydrodynamic enhancement of in-tube convective condensation heat transfer

Energy Technology Data Exchange (ETDEWEB)

Sadek, H.; Robinson, A.J.; Ching, C.Y.; Shoukri, M. [McMaster University, Department of Mechanical Engineering, Hamilton, Ont. (Canada); Cotton, J.S. [Dana Corporation, Long Manufacturing Division, Oakville, Ont. (Canada)

2006-05-15

An experimental investigation of electrohydrodynamic (EHD) augmentation of heat transfer for in-tube condensation of flowing refrigerant HFC-134a has been performed in a horizontal, single-pass, counter-current heat exchanger with a rod electrode placed in the centre of the tube. The effects of varying the mass flux (55kg/m{sup 2}s=drop was increased by a factor 1.5 at the same conditions of the maximum heat transfer enhancement. The improved heat transfer performance and pressure drop penalty are due to flow regime transition from stratified flow to annular flow as has been deduced from the surface temperature profiles along the top and bottom surfaces of the tube. (author)

Tube vibration in industrial size test heat exchanger

International Nuclear Information System (INIS)

Halle, H.; Wambsganss, M.W.

1980-03-01

Tube vibration data from tests of a specially built and instrumented, industrial-type, shell-and-tube heat exchanger are reported. The heat exchanger is nominally 0.6 m (2 ft) in dia and 3.7 m (12 ft) long. Both full tube and no-tubes-in-window bundles were tested for inlet/outlet nozzles of different sizes and with the tubes supported by seven, equally-spaced, single-segmental baffles. Prior to water flow testing, natural frequencies and damping of representative tubes were measured in air and water. Flow testing was accomplished by increasing the flow rates in stepwise fashion and also by sweeping through a selected range of flow rates. The primary variables measured and reported are tube accelerations and/or displacements and pressure drop through the bundle. Tests of the full tube bundle configuration revealed tube rattling to occur at intermediate flow rates, and fluidelastic instability, with resultant tube impacting, to occur when the flow rate exceeded a threshold level; principally, the four-span tubes were involved in the regions immediately adjacent to the baffle cut. For the range of flow rates tested, fluidelastic instability was not achieved in the no-tubes-in-window bundle; in this configuration the tubes are supported by all seven baffles and are, therefore, stiffer

Holden gas-fired furnace baseline data. Revision 1

International Nuclear Information System (INIS)

Weatherspoon, K.A.

1996-11-01

The Holden gas-fired furnace is used in the enriched uranium recovery process to dry and combust small batches of combustibles. The ash is further processed. The furnace operates by allowing a short natural gas flame to burn over the face of a wall of porous fire brick on two sides of the furnace. Each firing wall uses two main burners and a pilot burner to heat the porous fire brick to a luminous glow. Regulators and orifice valves are used to provide a minimum gas pressure of 4 in. water column at a rate of approximately 1,450 scf/h to the burners. The gas flow rate was calculated by determining the gas flow appropriate for the instrumentation in the gas line. Observed flame length and vendor literature were used to calculate pilot burner gas consumption. Air for combustion, purging, and cooling is supplied by a single blower. Rough calculations of the air-flow distribution in piping entering the furnace show that air flow to the burners approximately agrees with the calculated natural gas flow. A simple on/off control loop is used to maintain a temperature of 1,000 F in the furnace chamber. Hoods and glove boxes provide contamination control during furnace loading and unloading and ash handling. Fan EF-120 exhausts the hoods, glove boxes, and furnace through filters to Stack 33. A review of the furnace safety shows that safety is ensured by design, interlocks, procedure, and a safety system. Recommendations for safety improvements include installation of both a timed ignition system and a combustible-gas monitor near the furnace. Contamination control in the area could be improved by redesigning the loading hood face and replacing worn gaskets throughout the system. 33 refs., 16 figs

The use of blast furnace slag

Directory of Open Access Journals (Sweden)

V. Václavík

2012-10-01

Full Text Available The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

Numerical Analysis for Heat Transfer Characteristics of Elliptic Fin-Tube Heat Exchanger with Various Shapes

Energy Technology Data Exchange (ETDEWEB)

Yoo, Jae Hwan; Yoon, Jun Kyu [Gachon Univ., Seongnam (Korea, Republic of)

2013-04-15

In this study, the characteristics of the heat transfer coefficient and pressure drop were numerically analyzed according to the axis ratio (A R), pitch, location of vortex generator, and bump phase of the tube surface about an elliptical fin-tube heat exchanger. The boundary condition for CAD analysis was decided as a tube surface temperature of 348 K and inlet air velocity of 1.5 m/s. RCM 7th turbulent model was chosen as the numerical analysis for the sensitivity level. The analysis results indicated that the A R and transverse pitch decreased whereas the heat transfer coefficient increased. On the other hand, there was little difference in the longitudinal pitch. Furthermore, the heat transfer rate was more favorable when the vortex generator was located in front of the tube. Also, the bump phase of the tube surface indicated that the pressure drop and heat transfer were more favorable with the circle type than with the serrated type.

Furnace for treating bituminous material

Energy Technology Data Exchange (ETDEWEB)

Klotzer, M

1922-04-28

A furnace with saw-teeth-like profiled hearth, which by means of a kind of shaking slide executes a backward and forward motion, for carrying out the process according to Patent 422,391. It is characterized in that the stroke of the hearth moving in the furnace is smaller than the length of the profile tooth and the height of the feed is held less than the tooth height.

Enhancement of heat transfer. The performance of micro-fin tubes

International Nuclear Information System (INIS)

Muzzio, A.

2001-01-01

Micro-fin tubes are characterised by numerous, very small integral fins that spiral down the inner surface. A very interesting feature of their performance in flow boiling and condensation is a large heat transfer enhancement accompanied by a low pressure drop penalty. This paper presents a general overview of micro-fin tubes and of their performance in evaporation, condensation and single-phase flow [it

Experimental and analytical study of two-phase pressure drops during evaporation in horizontal tubes

OpenAIRE

Moreno Quibén, Jesús; Thome, John Richard

2007-01-01

Two-phase flow of gases and liquids or vapors and liquids in pipes, channels, equipment, etc. is frequently encountered in industry and has been studied intensively for many years. The reliable prediction of pressure drop in two-phase flow is thereby an important aim. Because of the complexity of these types of flow, empirical or semiempirical relationships are only of limited reliability and pressure drops predicted using leading methods may differ by up to 100%. In order to improve predicti...

Nitrogen oxide emissions from a kraft recovery furnace

International Nuclear Information System (INIS)

Prouty, A.L.; Stuart, R.C.; Caron, A.L.

1993-01-01

Nitrogen Oxide (NOx) emissions from a rebuilt kraft recovery furnace slightly exceeded the specified limit of 1.1 lb/ton (0.55 kg/metric ton) of black-liquor solids. Mill trials were undertaken to determine whether NOx emissions could be minimized by modifying furnace operation. NOx emissions increased when secondary air was shifted to tertiary ports. NOx emissions fell when the amounts of primary and total air were decreased, but this increased emissions of other pollutants. After demonstrating that best operation of the furnace could not meet the permit with an emissions limit that matched the furnace's performance at best operation

Method of operating a centrifugal plasma arc furnace

International Nuclear Information System (INIS)

Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.

1998-01-01

A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe 3 O 4 . Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe 2 O 3 . Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs

Waste and dust utilisation in shaft furnaces

Directory of Open Access Journals (Sweden)

Senk, D.

2005-12-01

Full Text Available Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilized e.g. in agglomeration processes (sintering, pelletizing or briquetting and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverized coal (PC has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

Los residuos y polvos de filtro provenientes de la industria siderúrgica, de la obtención de metales no ferrosos y de otras industrias, pueden ser utilizados, por ejemplo, en procesos de aglomeración como sintetizado, peletizado o briqueteado. En su caso, estos pueden ser inyectados en los hornos de cuba. Este artículo se enfoca a la inyección de estos materiales en los hornos de cuba. El comportamiento de la combustión y reducción de los polvos ricos en hierro y carbono y también lodos que contienen plomo, zinc y compuestos alcalinos y otros residuos con o sin carbón pulverizado (CP fue examinado, cuando se inyectaron en hornos de cuba. Los siguientes hornos de cuba fueron examinados: Horno alto, cubilote, OxiCup y horno de cuba Imperial Smelting. Las investigaciones se llevaron a cabo a escala de laboratorio e industrial. Algunos residuos y polvos bajo ciertas condiciones, no sólo pueden ser reciclados, sino también mejoran la eficiencia de combustión en las toberas, la operación y productividad del horno.

Numerical and experimental study of a hydrodynamic cavitation tube

Science.gov (United States)

Hu, H.; Finch, J. A.; Zhou, Z.; Xu, Z.

1998-08-01

A numerical analysis of hydrodynamics in a cavitation tube used for activating fine particle flotation is described. Using numerical procedures developed for solving the turbulent k-ɛ model with boundary fitted coordinates, the stream function, vorticity, velocity, and pressure distributions in a cavitation tube were calculated. The calculated pressure distribution was found to be in excellent agreement with experimental results. The requirement of a pressure drop below approximately 10 m water for cavitation to occur was observed experimentally and confirmed by the model. The use of the numerical procedures for cavitation tube design is discussed briefly.

Multiple hearth furnace for reducing iron oxide

Science.gov (United States)

Brandon, Mark M [Charlotte, NC; True, Bradford G [Charlotte, NC

2012-03-13

A multiple moving hearth furnace (10) having a furnace housing (11) with at least two moving hearths (20) positioned laterally within the furnace housing, the hearths moving in opposite directions and each moving hearth (20) capable of being charged with at least one layer of iron oxide and carbon bearing material at one end, and being capable of discharging reduced material at the other end. A heat insulating partition (92) is positioned between adjacent moving hearths of at least portions of the conversion zones (13), and is capable of communicating gases between the atmospheres of the conversion zones of adjacent moving hearths. A drying/preheat zone (12), a conversion zone (13), and optionally a cooling zone (15) are sequentially positioned along each moving hearth (30) in the furnace housing (11).

Bacterial Biofilms in Jones Tubes.

Science.gov (United States)

Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

Impact of tubing length on hemodynamics in a simulated neonatal extracorporeal life support circuit.

Science.gov (United States)

Qiu, Feng; Uluer, Mehmet C; Kunselman, Allen; Clark, J Brian; Myers, John L; Undar, Akif

2010-11-01

During extracorporeal life support (ECLS), a large portion of the hemodynamic energy is lost to various components of the circuit. Minimization of this loss in the circuit leads to better vital organ perfusion and decreases the risk of systemic inflammation. In this study, we evaluated the hemodynamic properties of differing lengths of tubing in a simulated neonatal ECLS circuit. The neonatal ECLS circuit used in this study included a Capiox Baby RX05 oxygenator (Terumo Corporation, Tokyo, Japan), a Rotaflow centrifugal pump (MAQUET Cardiopulmonary AG, Hirrlingen, Germany), and a heater and cooler unit. An 8Fr Biomedicus arterial and a 10Fr Biomedicus venous cannula were connected to the pseudopatient. One-fourth inch tubing was used for both the arterial and the venous line. A Hoffman clamp was located upstream from the pseudopatient to maintain a certain patient pressure. Three pressure transducers were placed at different sites: postoxygenator, prearterial cannula, and postarterial cannula. The system was primed with Lactated Ringer's solution; human blood was then added to maintain a hematocrit of 40%. The volume of the pseudopatient was 500mL. We hemodynamically evaluated three circuits with different lengths of tubing: 6, 4, and 2 feet (182.88, 121.92, and 60.96 cm, respectively) for both arterial and venous lines; the priming volumes including all of the components of the circuits were 195, 155, and 115mL, respectively. In each circuit, we measured the pressure drops of the arterial tubing and the arterial cannula, as well as the flow rates at different rpm (1750-3000, 250 intervals) under three patient pressures (40, 60, and 80mm Hg). All the experiments were conducted at 37°C. The pressure drop across the arterial cannula is much larger than that of arterial tubing in all set-ups, especially under high flow rates. Upon cutting the tubing from 6 to 2 feet, the pressure drop of the arterial tubing decreased by half, while the pressure drop of the arterial

Application of Carbon Composite Bricks for Blast Furnace Hearth

Science.gov (United States)

Zuo, Haibin; Wang, Cong; Zhang, Jianliang; Zhao, Yongan; Jiao, Kexin

Traditional refractory materials for blast furnace hearth lining are mainly composed of carbon bricks and the ceramic cup. However, these materials can't meet the demands for long service life design of blast furnaces. In this paper, a new refractory called carbon composite brick (CCB) was introduced, which combined the advantages of carbon bricks and the ceramic cup. In this case, the resistance of the CCB against corrosion was equal to the ceramic cup and the thermal conductivity of the CCB was equal to carbon bricks. From the results of more than 20 blast furnaces, the CCB could be well used in small blast furnaces and large blast furnaces. In the bad condition of low grade burden and high smelting intensity, the CCB gave full play to the role of cooling system, and effectively resisted the erosion of hot metal to improve the service life of blast furnaces.

Preparation for microgravity - The role of the Microgravity Material Science Laboratory

Science.gov (United States)

Johnston, J. Christopher; Rosenthal, Bruce N.; Meyer, Maryjo B.; Glasgow, Thomas K.

1988-01-01

Experiments at the NASA Lewis Research Center's Microgravity Material Science Laboratory using physical and mathematical models to delineate the effects of gravity on processes of scientific and commercial interest are discussed. Where possible, transparent model systems are used to visually track convection, settling, crystal growth, phase separation, agglomeration, vapor transport, diffusive flow, and polymer reactions. Materials studied include metals, alloys, salts, glasses, ceramics, and polymers. Specific technologies discussed include the General Purpose furnace used in the study of metals and crystal growth, the isothermal dendrite growth apparatus, the electromagnetic levitator/instrumented drop tube, the high temperature directional solidification furnace, the ceramics and polymer laboratories and the center's computing facilities.

ASSERT validation against the Stern Laboratories' single-phase pressure drop tests

International Nuclear Information System (INIS)

Waddington, G.M.; Kiteley, J.C.; Carver, M.B.

1995-01-01

This paper describes the preliminary validation of ASSERT-IV against the single-phase pressure drop tests from the 37-element CHF (critical heat flux) experiments conducted at Stern Laboratories, and shows how this study fits into the overall ASSERT validation plan. The effects on the pressure drop of several friction and form loss models are evaluated, including the geometry-based K-factor model. The choice of friction factor has a small effect on the predicted channel pressure drop, compared to the form loss model choice. Using the uniform K-factors of Hameed, the computed pressure drops are in excellent agreement with the experimental results from the nominal pressure tube tests. For future ASSERT applications, either Hameed's uniform K-factors or the geometry-based model using Idelchik's thick-edged orifice equation are recommended, as are the friction factor correlations of Colebrook-White, Selander, and Aly and Groeneveld. More analysis of the geometry-based K-factor model is required. (author). 23 refs., 4 tabs., 9 figs

Condensation of nano-refrigerant inside a horizontal tube

Science.gov (United States)

Darzi, Milad; Sadoughi, M. K.; Sheikholeslami, M.

2018-05-01

In this paper, condensing pressure drop of refrigerant-based nanofluid inside a tube is studied. Isobutene was selected as the base fluid while CuO nanoparticles were utilized to prepare nano-refrigerant. However, for the feasibility of nanoparticle dispersion into the refrigerant, Polyester oil (POE) was utilized as lubricant oil and added to the pure refrigerant by 1% mass fraction. Various values of mass flux, vapor quality, concentration of nanoparticle are investigated. Results indicate that adding nanoparticles leads to enhance frictional pressure drop. Nanoparticles caused larger pressure drop penalty at relatively lower vapor qualities which may be attributed to the existing condensation flow pattern such that annular flow is less influenced by nanoparticles compared to intermittent flow regime.

Predictive control of thermal state of blast furnace

Science.gov (United States)

Barbasova, T. A.; Filimonova, A. A.

2018-05-01

The work describes the structure of the model for predictive control of the thermal state of a blast furnace. The proposed model contains the following input parameters: coke rate; theoretical combustion temperature, comprising: natural gas consumption, blasting temperature, humidity, oxygen, blast furnace cooling water; blast furnace gas utilization rate. The output parameter is the cast iron temperature. The results for determining the cast iron temperature were obtained following the identification using the Hammerstein-Wiener model. The result of solving the cast iron temperature stabilization problem was provided for the calculated values of process parameters of the target area of the respective blast furnace operation mode.

Pressure drop in two-phase He I natural circulation loop at low vapour quality

International Nuclear Information System (INIS)

Baudouy, B.

2003-01-01

Steady state pressure drop in a two-phase He I natural circulation loop has been measured at atmospheric pressure. Results are obtained up to 0.2 exit vapor quality for a 14-mm diameter copper tube heated over a length of 1.2 m. Pressure drop assessment, done with the momentum balance equation including subcooling, reveals that the homogeneous model and Friedel's friction multiplier associated with Huq and Loth's void fraction correlations predict data within 15%. (author)

The fate of injectant coal in blast furnaces: The origin of extractable materials of high molecular mass in blast furnace carryover dusts

Energy Technology Data Exchange (ETDEWEB)

Dong, S.N.; Wu, L.; Paterson, N.; Herod, A.A.; Dugwell, D.R.; Kandiyoti, R. [University of London Imperial College of Science & Technology, London (United Kingdom). Dept. of Chemical Engineering

2005-07-01

The aim of the work was to investigate the fate of injectant coal in blast furnaces and the origin of extractable materials in blast furnace carryover dusts. Two sets of samples including injectant coal and the corresponding carryover dusts from a full sized blast furnace and a pilot scale rig have been examined. The samples were extracted using 1-methyl-2-pyrrolidinone (NMP) solvent and the extracts studied by size exclusion chromatography (SEC). The blast furnace carryover dust extracts contained high molecular weight carbonaceous material, of apparent mass corresponding to 10{sup 7}-10{sup 8} u, by polystyrene calibration. In contrast, the feed coke and char prepared in a wire mesh reactor under high temperature conditions did not give any extractable material. Meanwhile, controlled combustion experiments in a high-pressure wire mesh reactor suggest that the extent of combustion of injectant coal in the blast furnace tuyeres and raceways is limited by time of exposure and very low oxygen concentration. It is thus likely that the extractable, soot-like material in the blast furnace dust originated in tars is released by the injectant coal. Our results suggest that the unburned tars were thermally altered during the upward path within the furnace, giving rise to the formation of heavy molecular weight (soot-like) materials.

Particle scavenging in a cylindrical ultrasonic standing wave field using levitated drops

Science.gov (United States)

Merrell, Tyler; Saylor, J. R.

2015-11-01

A cylindrical ultrasonic standing wave field was generated in a tube containing a flow of particles and fog. Both the particles and fog drops were concentrated in the nodes of the standing wave field where they combined and then grew large enough to fall out of the system. In this way particles were scavenged from the system, cleaning the air. While this approach has been attempted using a standing wave field established between disc-shaped transducers, a cylindrical resonator has not been used for this purpose heretofore. The resonator was constructed by bolting three Langevin transducers to an aluminum tube. The benefit of the cylindrical geometry is that the acoustic energy is focused. Furthermore, the residence time of the particle in the field can be increased by increasing the length of the resonator. An additional benefit of this approach is that tubes located downstream of the resonator were acoustically excited, acting as passive resonators that enhanced the scavenging process. The performance of this system on scavenging particles is presented as a function of particle diameter and volumetric flow rate. It is noted that, when operated without particles, the setup can be used to remove drops and shows promise for liquid aerosol retention from systems where these losses can be financially disadvantageous and/or hazardous.

A new role for reduction in pressure drop in cyclones using computational fluid dynamics techniques

Directory of Open Access Journals (Sweden)

D. Noriler

2004-01-01

Full Text Available In this work a new mechanical device to improve the gas flow in cyclones by pressure drop reduction is presented and discussed. This behavior occurs due to the effects of introducing swirling breakdown phenomenon at the inlet of the vortex finder tube. The device consists of a tube with two gas inlets in an appositive spiral flux that produces a sudden reduction in the tangential velocity peak responsible for practically 80 % of the pressure drop in cyclones. In turn, peak reduction causes a decrease in pressure drop by a breakdown of the swirling, and because of this the solid particles tend to move faster toward the wall , increasing collection efficiency. As a result of this phenomenon the overall performance of cyclones is improved. Numerical simulations with 3-D, transient, asymmetric and anisotropic turbulence closure by differential Reynolds stress for Lapple and Stairmand standard geometries of 0.3 m in diameter, show a reduction in pressure drop of 20 % and a shift of the tangential velocity peak toward the wall. All numerical experiments were carried out with a commercial CFD code showing numerical stability and good convergence rates with high-order interpolation schemes, SIMPLEC pressure-velocity coupling and other numerical features.

Quantitative experiments on thermal hydraulic characteristics of an annular tube with twisted fins

International Nuclear Information System (INIS)

Ezato, Koichiro; Dairaku, Masayuki; Taniguchi, Masaki; Sato, Kazuyoshi; Suzuki, Satoshi; Akiba, Masato

2003-11-01

Thermal hydraulic experiments measuring critical heat flux (CHF) and pressure drop of an annular tube with twisted fins, ''annular swirl tube'', has been performed to examine its applicability to the ITER divertor cooling structure. The annular swirl tube consists of two concentric circular tubes, the outer and inner tubes. The outer tube with outer and inner diameters (OD and ID) of 21 mm and 15 mm is made of Cu-alloy that is CuCrZr and oe of candidate materials of the ITER divertor cooling tube. The inner tube with OD of 11 mm and ID of 9 mm is made of stainless steal. It has an external swirl fin with twist ratio (y) of three to enhance its heat transfer performance. In this tube, cooling water flows inside of the inner tube first, and then returns into an annulus between the outer and inner tubes with a swirl flow at an end-return of the cooling tube. The CHF experiments show that no degradation of CHF of the annular swirl tube in comparison with the conventional swirl tube whose dimensions are similar to those of the outer tube of the annular swirl tube. A minimum axial velocity of 7.1 m/s is required to remove the incident heat flux of 28MW/m 2 , the ITER design value. Applicability of the JAERI's correlation for the heat transfer to the annular swirl tube is also demonstrated by comparing the experimental results with those of the numerical analysis. The friction factor correlation for the annular flow with the twisted fins is also proposed for the hydrodynamic design of the ITER vertical target. The least pressure drop at the end-return is obtained by using the hemispherical end-plug. Its radius is the same as that of ID of the outer cooling tube. These results show that thermal-hydraulic performance of the annular swirl tube is promising in application to the cooling structure for the ITER vertical target. (author)

Arrangement of furnaces and retorts for the distillation of shale, etc. [injection of hot air

Energy Technology Data Exchange (ETDEWEB)

Lahore, M

1846-01-31

The patent is concerned with the distillation of dried materials, the distillation being facilitated by injection of hot air into the retorts. Figures show apparatus for heating the air, consisting of a series of pipes, connected together and placed horizontally in the interior of the furnace on bricks arranged in such a way that the flames and smoke circulate, as shown, around each pipe, touching first all the surface of the large one placed in the center. The air enters this tube, and from it passes into the others which it runs through successively, coming finally into the last pipe, being heated in this journey to a very high temperature. The last tube ends in a bell from which different branches start, each supplied with stop-cocks, to lead this hot air into the different sections of the retort. With the stop-cocks the quantity of air can be regulated at will, in the compartment of the retort, for accelerating the operation more or less.

Experiment study of a quartz tube falling particle receiver

Institute of Scientific and Technical Information of China (English)

Tianjian WANG; Fengwu BAI; Shunzhou CHU; Xiliang ZHANG; Zhifeng WANG

2017-01-01

This paper presents an experimental evaluation of a specially designed falling particle receiver.A quartz tube was used in the design,with which the particles would not be blown away by wind.Concentrated solar radiation was absorbed and converted into thermal energy by the solid particles flowed inside the quartz tube.Several experiments were conducted to test the dynamic thermal performance of the receiver on solar furnace system.During the experiments,the maximum particle temperature rise is 212℃,with an efficiency of 61.2％,which shows a good thermal performance with a falling distance of 0.2 m in a small scale particle receiver.The average outlet particle temperature is affected by direct normal irradiance (DNI) and other factors such as wind speed.The solid particles obtain a larger viscosity with a higher temperature while smaller solid particles are easier to get stuck in the helix quartz tube.The heat capacity of the silicon carbide gets larger with the rise of particle temperature,because as the temperature of solid particles increases,the temperature rise of the silicon carbide decreases.

Heat transfer performance during condensation of R-134a inside helicoidal tubes

International Nuclear Information System (INIS)

Al-Hajeri, M.H.; Koluib, A.M.; Mosaad, M.; Al-Kulaib, S.

2007-01-01

This paper reports an experimental investigation of condensation heat transfer and pressure drop of an ozone friendly refrigerant, R-134a, inside a helical tube for climatic conditioning of hot regions. This study concerns the condensation of R-134a flowing through annular helical tubes with different operating refrigerant saturated temperatures. The average pressure drop is measured and compared with data from relevant literature. The measurements of R-134a were performed on mass flow flux ranges from 50 to 680 kg/m 2 s. The study provides experimental data that could be used for the design and development of more efficient condensers for refrigeration and air conditioning (A/C) systems working with the same refrigerant

Effect of surrounding gas temperature on the morphological evolution of TiO2 nanoparticles generated by laser ablation in tubular furnace

International Nuclear Information System (INIS)

Tsuji, Masayuki; Seto, Takafumi; Otani, Yoshio

2012-01-01

Titanium oxide nanoparticles are synthesized by laser ablation of Ti target in oxygen atmosphere under well-controlled temperature profiles in a tubular furnace. The size and the shape of generated nanoparticles are varied by changing the temperature of furnace. The mobility-based size distributions of generated air-borne nanoparticles are measured using a scanning mobility particle sizer, and the size distributions of primary particles are analyzed by a scanning electron microscope. When the particles are generated by laser ablation at the room temperature, the particles are agglomerates in gas phase with the average mobility diameter of 117 nm and the mean diameter of primary particles of 11 nm. The primary particle diameter increases from 11 to 24 nm by raising the furnace temperature up to 800 °C. Since the mass of Ti vapor ablated from a target is found to be constant regardless of the furnace temperature, this particle growth may be attributed to the reduction in nuclei number as a result of mild quenching at higher temperatures. As the temperature reaches higher than 1,000 °C, the mobility diameter suddenly drops and the primary particle diameter increases due to sintering, and at 1,200 °C the mobility diameter coincides with the primary particle diameter. Since the laser oven method offers an independent control of vapor concentration and the temperature of surrounding atmosphere, it is an effective tool to study the formation process of nanoparticles from primary particles with a given size.

Effect of drag-reducing polymers on Tubing Performance Curve (TPC) in vertical gas-liquid flows

NARCIS (Netherlands)

Shoeibi Omrani, P.; Veltin, J.; Turkenburg, D.H.

2014-01-01

This paper discusses the effect of drag reducing polymers on the Tubing Performance Curve (TPC) of vertical air-water flows at near atmospheric conditions. The effect of polymer concentration, liquid and gas flow rates on the pressure drop curve (Tubing Performance Curve) was investigated

BPM Motors in Residential Gas Furnaces: What are the Savings?

OpenAIRE

Lutz, James; Franco, Victor; Lekov, Alex; Wong-Parodi, Gabrielle

2006-01-01

Residential gas furnaces contain blowers to distribute warm air. Currently, furnace blowers use either a Permanent Split Capacitor (PSC) or a Brushless Permanent Magnet (BPM) motor. Blowers account for the majority of furnace electricity consumption. Therefore, accurate determination of the blower electricity consumption is important for understanding electricity consumption of furnaces. The electricity consumption of blower motors depends on the static pressure across the blower. This p...

An Investigation on Cocombustion Behaviors of Hydrothermally Treated Municipal Solid Waste with Coal Using a Drop-Tube Reactor

Directory of Open Access Journals (Sweden)

Liang Lu

2012-01-01

Full Text Available This work aims at demonstrating the feasibility of replacing Indonesian coal (INC with hydrothermally treated municipal solid waste (MSWH in cocombustion with high ash Indian coal (IC. The combustion efficiencies and emissions (CO, NO of MSWH, INC and their blends with IC for a series of tests performed under a range of temperatures and air conditions were tested in a drop-tube reactor (DTR. The results showed the following. The combustion efficiency of IC was increased by blending both MSWH and INC and CO emission was reduced with increasing temperature. For NO emission, the blending of MSWH led to the increase of NO concentration whereas the effects of INC depended on the temperature. The combustion behaviors of IC-MSWH blend were comparable to those of the IC-INC blend indicating it is possible for MSWH to become a good substitute for INC supporting IC combustion. Moreover, the CO emission fell while the NO emission rose with increasing excess air for IC-MSWH blend at 900°C and the highest combustion efficiency was obtained at the excess air of 1.9. The existence of moisture in the cocombustion system of IC-MSWH blend could slightly improve the combustion efficiency, reduce CO, and increase NO.

Pressure drop in two-phase He I natural circulation loop at low vapour quality

Energy Technology Data Exchange (ETDEWEB)

Baudouy, B

2003-01-01

Steady state pressure drop in a two-phase He I natural circulation loop has been measured at atmospheric pressure. Results are obtained up to 0.2 exit vapor quality for a 14-mm diameter copper tube heated over a length of 1.2 m. Pressure drop assessment, done with the momentum balance equation including subcooling, reveals that the homogeneous model and Friedel's friction multiplier associated with Huq and Loth's void fraction correlations predict data within 15%. (author)

Disc-retained tubes for radiologically inserted gastrostomy (RIG): Not up to the job?

International Nuclear Information System (INIS)

Kibriya, N.; Wilbraham, L.; Mullan, D.; Puro, P.; Vasileuskaya, S.; Edwards, D.W.; Laasch, H.-U.

2013-01-01

Aim: To assess the insertion procedure and performance of disc-retained gastrostomy tubes, recording complications and accidental displacements by prospective audit, and to determine whether primary placement of the tube off-licence was feasible. Materials and methods: Disc-retained 12 F single-lumen Monarch gastrostomy tubes (Enteral UK, Selby, UK) were inserted by three gastrointestinal interventional radiologists in a supra-regional cancer centre. The 12 F tubes required a 20 F peel-away sheath with four-point gastropexy fixation and were placed under conscious sedation, using electrocardiogram (EEG) bispectral index monitoring. Follow-up was performed in an in-house gastrostomy drop-in clinic at 1 week and 1 month, supplemented with weekly telephone follow-up. Patients also had open access to the gastrostomy drop-in clinic for immediate advice and complication management. Results: Eighteen patients underwent primary insertion of a Monarch gastrostomy tube over 5 months. A total of 6/18 (33%) tubes displaced; 4/18 (22%) completely, 2/18 (11%) occult into the peritoneum. Four of 18 (22%) patients developed infection at the stoma site. Due to the unexpectedly poor performance of the tube, the study was terminated early. Conclusion: Initial experience with the Monarch disc-retained gastrostomy tube demonstrates it unsuitable for primary placement with current protocols. In view of the potentially serious complications, the Medicines and Healthcare Products Regulatory Agency (MHRA) has been informed. A request has been made to the distributer to reassess the tube design and/or review the procedure promoted for primary placement

Optimization of Peripheral Finned-Tube Evaporators Using Entropy Generation Minimization

OpenAIRE

Pussoli, Bruno; Barbosa Jr., Jader; da Silva, Luciana; Kaviany, Massoud

2012-01-01

The peripheral finned-tube (PFT) is a new geometry for enhanced air-side heat transfer under moisture condensate blockage (evaporators). It consists of individual hexagonal (peripheral) fin arrangements with radial fins whose bases are attached to the tubes and tips are interconnected with the peripheral fins. In this paper, experimentally validated semi-empirical models for the air-side heat transfer and pressure drop are combined with the entropy generation minimization theory to determine ...

Programmable temperature regulator of VAO-1 furnace

International Nuclear Information System (INIS)

Zahalka, F.

1979-01-01

A programmable temperature controller is described for a furnace for high-level waste processing. Furnace temperature is controlled by a program compiled from a combination of 3 parts with different linear increments or decrements of time dependent temperature and 2 parts with isothermal control for over a preset period. The equipment consists essentially of a programming unit, a programmed digital-to-analog converter and a power unit. The design is described in detail and its specifications are given. The maximum operating temperature of 1500 degC may be reached in the furnace charge section. (B.S.)

A new compact fixed-point blackbody furnace

International Nuclear Information System (INIS)

Hiraka, K.; Oikawa, H.; Shimizu, T.; Kadoya, S.; Kobayashi, T.; Yamada, Y.; Ishii, J.

2013-01-01

More and more NMIs are realizing their primary scale themselves with fixed-point blackbodies as their reference standard. However, commercially available fixed-point blackbody furnaces of sufficient quality are not always easy to obtain. CHINO Corp. and NMIJ, AIST jointly developed a new compact fixed-point blackbody furnace. The new furnace has such features as 1) improved temperature uniformity when compared to previous products, enabling better plateau quality, 2) adoption of the hybrid fixed-point cell structure with internal insulation to improve robustness and thereby to extend lifetime, 3) easily ejectable and replaceable heater unit and fixed-point cell design, leading to reduced maintenance cost, 4) interchangeability among multiple fixed points from In to Cu points. The replaceable cell feature facilitates long term maintenance of the scale through management of a group of fixed-point cells of the same type. The compact furnace is easily transportable and therefore can also function as a traveling standard for disseminating the radiation temperature scale, and for maintaining the scale at the secondary level and industrial calibration laboratories. It is expected that the furnace will play a key role of the traveling standard in the anticipated APMP supplementary comparison of the radiation thermometry scale

Electric melting furnace for waste solidification

International Nuclear Information System (INIS)

Masaki, Toshio.

1990-01-01

To avoid electric troubles or reduction of waste processing performance even when platinum group elements are contained in wastes to be applied with glass solidification. For this purpose, a side electrode is disposed to the side wall of a melting vessel and a central electrode serving as a counter electrode is disposed about at the center inside the melting vessel. With such a constitution, if conductive materials are deposited at the bottom of the furnace or the bottom of the melting vessel, heating currents flow selectively between the side electrode and the central electrode. Accordingly, no electric currents flow through the conductive deposits thereby enabling to prevent abnormal heating in the bottom of the furnace. Further, heat generated by electric supply between the side electrode and the central electrode is supplied efficiently to raw material on the surface of the molten glass liquid to improve the processing performance. Further, disposition of the bottom electrode at the bottom of the furnace enables current supply between the central electrode and the bottom electrode to facilitate the temperature control for the molten glass in the furnace than in the conventional structure. (I.S.)

Displacer Diameter Effect in Displacer Pulse Tube Refrigerator

Science.gov (United States)

Zhu, Shaowei

2017-12-01

Gas driving displacer pulse tube refrigerators are one of the work recovery type of pulse tube refrigerators whose theoretical efficiency is the same as Stirling refrigerators'. Its cooling power is from the displacement of the displacer. Displace diameter, rod diameter and pressure drop of the regenerator influence the displacement, which are investigated by numerical simulation. It is shown that the displacement ratio of the displacer over the piston is almost not affected by the displacer diameter at the same rod diameter ratio, or displacer with different diameters almost has the same performance.

Experimental heat transfer in tube bundle

International Nuclear Information System (INIS)

Khattab, M.; Mariy, A.; Habib, M.

1983-01-01

Previous work has looked for the problem of heat transfer with flow parallel to rod bundle either by treating each rod individually as a separate channel or by treating the bundle as one unit. The present work will consider the existence of both the central and corner rods simultaneously inside the cluster itself under the same working conditions. The test section is geometrically similar to the fuel assembly of the Egyptian Research Reactor-1. The hydro-thermal performance of bundle having 16 - stainless steel tubes arranged in square array of 1.5 pitch to diameter ratio is investigated. Surface temperature and pressure distributions are determined. Average heat transfer coefficient for both central and corner tubes are correlated. Also, pressure drop and friction factor correlations are predicted. The maximum experimental range of the measured parameters are determined in the nonboiling region at 1400 Reynolds number and 3.64 W/cm 2 . It is found that the average heat transfer coefficient of the central tube is higher than that of the corner tube by 27%. Comparison with the previous work shows satisfactory agreement particularly with the circular tubes correlation - Dittus et al. - at 104 Reynolds number

Evaporation of R134a in a horizontal herringbone microfin tube: heat transfer and pressure drop

Energy Technology Data Exchange (ETDEWEB)

Wellsandt, S; Vamling, L [Chalmers University of Technology, Gothenburg (Sweden). Department of Chemical Engineering and Environmental Science, Heat and Power Technology

2005-09-01

An experimental investigation of in-tube evaporation of R134a has been carried out for a 4 m long herringbone microfin tube with an outer diameter of 9.53 mm. Measured local heat transfer coefficients and pressure losses are reported for evaporation temperatures between -0.7 and 10.1 {sup o}C and mass flow rates between 162 and 366 kg m{sup -2} s{sup -1}. Results from this work are compared to experimental results from literature as well as predicted values from some available helical microfin correlations. Differences in heat transfer mechanisms between helical and herringbone microfin tubes are discussed, as heat transfer coefficients in the investigated herringbone tube tend to peak at lower vapour qualities compared to helical microfins. Correlations developed for helical microfin tubes generally predict experimental values within {+-}30% for vapour qualities below 50%. However, at higher qualities none of the correlations are able to reflect the early peak of heat transfer coefficients. Predicted pressure gradients reproduce measured values in general within {+-}20%. (author)

Failure maps for internally pressurized Zr-2.5% Nb pressure tubes with circumferential temperature variations

International Nuclear Information System (INIS)

Shewfelt, R.S.W.

1986-01-01

During some postulated loss-of-coolant accidents, the pressure tube temperature may rise before the internal pressure drops, causing the pressure tube to balloon. The temperature around the pressure tube circumference would likely be nonuniform, producing localized deformation that could possibly cause failure. The computer program, GRAD, was used to determine the circumferential temperature distribution required to cause an internally pressurized Zr-2.5% Nb pressure tube to fail before coming into full contact with its calandria tube. These results were used to construct failure maps. 7 refs

High temperature aircraft research furnace facilities

Science.gov (United States)

Smith, James E., Jr.; Cashon, John L.

1992-01-01

Focus is on the design, fabrication, and development of the High Temperature Aircraft Research Furnace Facilities (HTARFF). The HTARFF was developed to process electrically conductive materials with high melting points in a low gravity environment. The basic principle of operation is to accurately translate a high temperature arc-plasma gas front as it orbits around a cylindrical sample, thereby making it possible to precisely traverse the entire surface of a sample. The furnace utilizes the gas-tungsten-arc-welding (GTAW) process, also commonly referred to as Tungsten-Inert-Gas (TIG). The HTARFF was developed to further research efforts in the areas of directional solidification, float-zone processing, welding in a low-gravity environment, and segregation effects in metals. The furnace is intended for use aboard the NASA-JSC Reduced Gravity Program KC-135A Aircraft.

A method to determine the dampening system of control rod drop mechanism for PWR reactors

International Nuclear Information System (INIS)

Trindade, C.E.; Mattos, J.R.L. de; Perrotta, J.A.

1988-08-01

A method to determine the Control Assembly damping drop system (dashpot/guide tube) was developed. It's presented a theoretical model, an experimental device and the procedures to determine this system, which is used in PWR reactors. (author) [pt

Passive heat transfer enhancement in 3D corrugated tube

DEFF Research Database (Denmark)

Navickaité, Kristina; Engelbrecht, Kurt; Bahl, Christian

transfer and fluid flow with a constant wall temperature and total pressure drop. The governing equations for these problems were solved using the Finite Element Method. The results of numerical modelling show significant increase in NTU for double corrugated tubes compared to a circular tube. The friction......An innovative hydraulic design was studied for corrugated tube geometry for a heat exchanger. An ellipse based double corrugation was used as a concept of the geometry. The hydraulic diameter (Dh) is maintained over the tube length while the shape of the cross section varies continuously along...... the flow direction. 38 corrugated tubes with a Dh of 5 mm were studied numerically with corrugation heights from 0.23 to 0.69 mm and corrugation periods from 5 to 50 mm for laminar flow with water. Computational fluid dynamics (CFD) is used as a tool to study the effect of corrugation geometry on heat...

A burnout prediction model based around char morphology

Energy Technology Data Exchange (ETDEWEB)

Tao Wu; Edward Lester; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

2006-05-15

Several combustion models have been developed that can make predictions about coal burnout and burnout potential. Most of these kinetic models require standard parameters such as volatile content and particle size to make a burnout prediction. This article presents a new model called the char burnout (ChB) model, which also uses detailed information about char morphology in its prediction. The input data to the model is based on information derived from two different image analysis techniques. One technique generates characterization data from real char samples, and the other predicts char types based on characterization data from image analysis of coal particles. The pyrolyzed chars in this study were created in a drop tube furnace operating at 1300{sup o}C, 200 ms, and 1% oxygen. Modeling results were compared with a different carbon burnout kinetic model as well as the actual burnout data from refiring the same chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen, and residence times of 200, 400, and 600 ms. A good agreement between ChB model and experimental data indicates that the inclusion of char morphology in combustion models could well improve model predictions. 38 refs., 5 figs., 6 tabs.

Assessment of selected furnace technologies for RWMC waste

International Nuclear Information System (INIS)

Batdorf, J.; Gillins, R.; Anderson, G.L.

1992-03-01

This report provides a description and initial evaluation of five selected thermal treatment (furnace) technologies, in support of earlier thermal technologies scoping work for application to the Idaho National Engineering Laboratory Radioactive Waste Management Complex (RWMC) buried wastes. The cyclone furnace, molten salt processor, microwave melter, ausmelt (fuel fired lance) furnace, and molten metal processor technologies are evaluated. A system description and brief development history are provided. The state of development of each technology is assessed, relative to treatment of RWMC buried waste

Uranium casting furnace automatic temperature control development

International Nuclear Information System (INIS)

Lind, R.F.

1992-01-01

Development of an automatic molten uranium temperature control system for use on batch-type induction casting furnaces is described. Implementation of a two-color optical pyrometer, development of an optical scanner for the pyrometer, determination of furnace thermal dynamics, and design of control systems are addressed. The optical scanning system is shown to greatly improve pyrometer measurement repeatability, particularly where heavy floating slag accumulations cause surface temperature gradients. Thermal dynamics of the furnaces were determined by applying least-squares system identification techniques to actual production data. A unity feedback control system utilizing a proportional-integral-derivative compensator is designed by using frequency-domain techniques. 14 refs

A furnace for firing carbon products

Energy Technology Data Exchange (ETDEWEB)

Sudavskii, A M

1979-12-05

A furnace for firing carbon products is patented that consists of several chambers with a perforated hearth, which are interconnected by a lower and an upper reservoir with a locking fixture, and a flue. In order to intensify the firing process by increasing the specific hearth productivity, the flue is connected to the upper reservoir. A block diagram of the patented furnace is given, together with a description of its operation.

Elements of the electric arc furnace's environmental management

Science.gov (United States)

Ioana, Adrian; Semenescu, Augustin; Costoiu, Mihnea; Marcu, Dragoş

2017-12-01

The paper presents a theoretical and experimental analysis of the polluting generating mechanisms for steel making in the Electric Arc Furnaces (EAF). The scheme for the environment's polluting system through the EAF is designed and presented in this paper. The ecological experimenting consisted of determining by specialized measures of the dust percentage in the evacuated gases from the EAF and of thereof gas pollutants. From the point of view of reducing the impact on the environment, the main problem of the electric arc furnace (EAF) is the optimization of the powder collecting from the process gases, both from the furnace and from the work-area. The paper deals with the best dependence between the aggregate's constructive, functional and technological factors, which are necessary for the furnace's ecologization and for its energetically-technologically performances increasing.

A heat transfer study for vertical straight-tube steam generators heated by liquid metal

International Nuclear Information System (INIS)

Valette, M.

1984-04-01

A single-tube mockup of a vertical straight-tube steam generator heated by sodium-potassium alloy NaK was submitted to thermal and hydraulic testing in conditions representative of fast breeder reactor operation. The mockup consisted of a 10mm I.D. ferritic steel heat exchange tube centered inside a cylindrical stainless steel shell. The complete assembly was 20.9 meters long. Water flowed upward inside the exchange tube, and NaK flowed downward in the annular gap between the tube and the shell. The steam outlet pressure ranged from 90 to 195 bars, while the liquid metal temperature at the mockup inlet was between 480 and 580 0 C. The water flowrate in the tube ranged from 153 to 2460 kg.m -2 .s -1 . During the tests the fluid inlet and outlet temperatures, flowrate and pressures were measured, as was the NaK temperature profile over the full length of the device. The test results were subsequently compared with heat exchange and pressure drop values calculated using the standard formulas for straight-tube heat exchangers. The heat exchange coefficients predicted by these correlations in the boiling zone were found to be largely overestimated, while the calculated pressure drop values proved satisfactory. A set of modified correlations is proposed to account for the observed phenomena, and for use in designing commercial units, provided the sodium flow in the tube bundle is adequately distributed

Energy transformation and flow topology in an elbow draft tube

Directory of Open Access Journals (Sweden)

Štefan D.

2012-06-01

Full Text Available Paper presents a computational study of energy transformation in two geometrical configurations of Kaplan turbine elbow draft tube. Pressure recovery, hydraulic efficiency and loss coefficient are evaluated for a series of flow rates and swirl numbers corresponding to operating regimes of the turbine. These integral characteristics are then correlated with local flow field properties identified by extraction of topological features. Main focus is to find the reasons for hydraulic efficiency drop of the elbow draft tube.

Methods for monitoring heat flow intensity in the blast furnace wall

Directory of Open Access Journals (Sweden)

L'. Dorčák

2010-04-01

Full Text Available In this paper we present the main features of an online system for real-time monitoring of the bottom part of the blast furnace. Firstly, monitoring concerns the furnace walls and furnace bottom temperatures measurement and their visualization. Secondly, monitored are the heat flows of the furnace walls and furnace bottom. In the case of two measured temperatures, the heat flow is calculated using multi-layer implicit difference scheme and in the case of only one measured temperature, the heat flow is calculated using a method based on application of fractional-order derivatives. Thirdly, monitored is the theoretical temperature of the blast furnace combustion process in the area of tuyeres.

Thermal Analysis of an Industrial Furnace

Directory of Open Access Journals (Sweden)

Mirko Filipponi

2016-10-01

Full Text Available Industries, which are mainly responsible for high energy consumption, need to invest in research projects in order to develop new managing systems for rational energy use, and to tackle the devastating effects of climate change caused by human behavior. The study described in this paper concerns the forging industry, where the production processes generally start with the heating of steel in furnaces, and continue with other processes, such as heat treatments and different forms of machining. One of the most critical operations, in terms of energy loss, is the opening of the furnace doors for insertion and extraction operations. During this time, the temperature of the furnaces decreases by hundreds of degrees in a few minutes. Because the dispersed heat needs to be supplied again through the combustion of fuel, increasing the consumption of energy and the pollutant emissions, the evaluation of the amount of lost energy is crucial for the development of systems which can contain this loss. To perform this study, CFD simulation software was used. Results show that when the door opens, because of temperature and pressure differences between the furnace and the ambient air, turbulence is created. Results also show that the amount of energy lost for an opening of 10 min for radiation, convection and conduction is equal to 5606 MJ where convection is the main contributor, with 5020 MJ. The model created, after being validated, has been applied to perform other simulations, in order to improve the energy performance of the furnace. Results show that reducing the opening time of the door saves energy and limits pollutant emissions.

Fluxless furnace brazing and its theoretical fundamentals

International Nuclear Information System (INIS)

Lison, R.

1979-01-01

In this paper the theoretical fundamental of fluxless furnace brazing are described. The necessary conditions for a wetting in the vacuum, under a inert-gas and with a reducing gas are discussed. Also other methods to reduce the oxygen partial pressure are described. Some applications of fluxless furnace brazing are outlined. (orig.) [de

Effect of pore size on performance of monolithic tube chromatography of large biomolecules.

Science.gov (United States)

Podgornik, Ales; Hamachi, Masataka; Isakari, Yu; Yoshimoto, Noriko; Yamamoto, Shuichi

2017-11-01

Effect of pore size on the performance of ion-exchange monolith tube chromatography of large biomolecules was investigated. Radial flow 1 mL polymer based monolith tubes of different pore sizes (1.5, 2, and 6 μm) were tested with model samples such as 20 mer poly T-DNA, basic proteins, and acidic proteins (molecular weight 14 000-670 000). Pressure drop, pH transient, the number of binding site, dynamic binding capacity, and peak width were examined. Pressure drop-flow rate curves and dynamic binding capacity values were well correlated with the nominal pore size. While duration of the pH transient curves depends on the pore size, it was found that pH duration normalized on estimated surface area was constant, indicating that the ligand density is the same. This was also confirmed by the constant number of binding site values being independent of pore size. The peak width values were similar to those for axial flow monolith chromatography. These results showed that it is easy to scale up axial flow monolith chromatography to radial flow monolith tube chromatography by choosing the right pore size in terms of the pressure drop and capacity. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experiments on condensation heat transfer characteristics inside a microfin tube with R410A

Energy Technology Data Exchange (ETDEWEB)

Han, D H; Cho, Y J [Korea University Graduate School, Seoul (Korea); Lee, K J; Park, S S [Korea University, Seoul (Korea)

2000-11-01

Due to the ozone depletion and global warming potentials, some refrigerants (CFCs and HCFCs) have been rapidly substituted. R410A is considered as the alternative refrigerant of R22 for the air-conditioners used at home and in industry. Experiments on the condensation heat transfer characteristics inside a smooth or a micro-fin tube with R410A are performed in this study. The test tubes 7/9.52 mm in outer diameters and 3 m in length are used. Varying the mass flux of the refrigerant and the condensation temperatures, the average heat transfer coefficients and pressure drop are investigated. It is shown that the heat transfer is enhanced and the amount of pressure drops are larger in the microfin tube than the smooth tube. From the heat transfer enhancement coefficient and the pressure penalty factor, it is found that the high heat transfer enhancement coefficients are obtained in the range of small mass flux while the penalty factors are almost equal. (author). 13 refs., 12 figs., 1 tab.

Low-cost evacuated-tube solar collector appendices. Final report

Energy Technology Data Exchange (ETDEWEB)

Beecher, D.T.

1980-05-31

A low cost solar heat energy collector module and array has been designed using the evacuated tube, selective absorber, air cooled concept. Glass tubing as used in fluorescent lamps with automatic sealing methods is a key feature of the evacuated tube design. A molded fiber glass concentrating reflector panel and sheet metal header assembly are proposed. Major design problems involved included the cost of materials and labor, thermal expansion and distortion problems, high stagnation and operating temperatures, isolation, thermal efficiency, sealing, joining, air pressure drop, and weight of the preassembled module. A cost of less than $5 per active square foot of collecting surface has been estimated for materials and labor of the module and its mounting frame.

Thermal design of horizontal tube boilers. Numerical and experimental investigation; Modelisation thermique de bouilleurs a tubes horizontaux. Etude numerique et validation experimentale

Energy Technology Data Exchange (ETDEWEB)

Roser, R.

1999-11-26

This work concerns the thermal design of kettle reboilers. Current methods are highly inaccurate, regarded to the correlations for external heat transfer coefficient at one tube scale, as well as to two-phase flow modelling at boiler scale. The aim of this work is to improve these thermal design methods. It contains an experimental investigation with typical operating conditions of such equipment: an hydrocarbon (n-pentane) with low mass flux. This investigation has lead to characterize the local flow pattern through void fraction measurements and, from this, to develop correlations for void fraction, pressure drop and heat transfer coefficient. The approach is original, since the developed correlations are based on the liquid velocity at minimum cross section area between tubes, as variable characterizing the hydrodynamic effects on pressure drop and heat transfer coefficient. These correlations are shown to give much better results than those suggested up to now in the literature, which are empirical transpositions from methods developed for inside tube flows. Furthermore, the numerical code MC3D has been applied using the correlations developed in this work, leading to a modeling of the two-phase flow in the boiler, which is a significant progress compared to current simplified methods. (author)

Two-phase flow and pressure drop in T-junctions with horizontal run and vertical branch

International Nuclear Information System (INIS)

Katsaounis, A.

1987-01-01

Visual observations of single- and two-phase dividing flow and pressure drop measurements were performed in T-junctions with horizontal run and vertical branch. Both tees used were geometrically similar, in a scale of 1:4. The measurements were performed for plug/slug and stratified flow pattern regime in horizontal tube. Based on the single-phase form-resistance pressure drop correlation of Gardel a corresponded calculation model was developed for the two-phase flow verified by the own measurements. (orig.) [de

Fuel sparing: Control of industrial furnaces using process gas as supplemental fuel

International Nuclear Information System (INIS)

Boisvert, Patrick G.; Runstedtler, Allan

2014-01-01

Combustible gases from industrial processes can be used to spare purchased fuels such as natural gas and avoid wasteful flaring of the process gases. One of the challenges of incorporating these gases into other furnaces is their intermittent availability. In order to incorporate the gases into a continuously operating furnace, the furnace control system must be carefully designed so that the payload is not affected by the changing fuel. This paper presents a transient computational fluid dynamics (CFD) model of an industrial furnace that supplements natural gas with carbon monoxide during furnace operation. A realistic control system of the furnace is simulated as part of the CFD calculation. The time dependent changes in fuels and air injection on the furnace operation is observed. It is found that there is a trade-off between over-controlling the furnace, which results in too sensitive a response to normal flow oscillations, and under-controlling, which results in a lagged response to the fuel change. - Highlights: •Intermittently available process gases used in a continuously operating furnace. •Study shows a trade-off between over-controlling and under-controlling the furnace. •Over-controlling: response too sensitive to normal flow oscillations. •Under-controlling: lagged response to changing fuel composition. •Normal flow oscillations in furnace would not be apparent in steady-state model

Mechanical design of the storage tubes in the HWVP canister storage building

International Nuclear Information System (INIS)

Divona, C.J.; Fages, R.; Janicek, G.P.; Mullally, J.A.

1993-01-01

Canisters of high-level waste from the Hanford Waste Vitrification Plant (HWVP) will be stored in an adjacent facility, the Canister Storage Building (CSB). The canisters are stored vertically in an array of tubes within the shielded vault area of the CSB. This paper describes the mechanical design of the storage tubes, the shield floor plugs that confine the waste within the tubes and the impact absorber system used to assure that the canisters are not breached in the event of an accidental drop. Installation and testing of the components is also discussed

Feasibility study of utilizing solar furnace technology in steel making industry

Energy Technology Data Exchange (ETDEWEB)

Abbaspoursani, K. [The Faculty of Mechanical Engineering, Takestan Islamic Azad University (Iran, Islamic Republic of)], Email: a.abbaspour@tiau.ac.ir; Tofigh, A.A.; Nahang Toudeshki, S.; Hadadian, A. [Department of Energy, Materials and Energy Research Center (Iran, Islamic Republic of)], Email: Ali.A.Tofigh@gmail.com, email: toudeshki@hotmail.com, email: Arash.Hadadian@gmail.com; Farahmandpour, B. [Iranian Fuel Conservation company (Iran, Islamic Republic of)], Email: farahmandpour@gmail.com

2011-07-01

In Iran, the casting industry consumes 33.6% of electricity production, and most of this electricity is used in the melting process. Currently, scrap preheating is done using electric arc furnaces and the aim of this study is to assess the feasibility of replacing electric arc furnaces with solar furnaces. The performance of solar furnaces in the Iran Alloy Steel Company under Yazd climate conditions was studied. It was found that the solar irradiation time and solar insulation are sufficient to operate a solar furnace with the capacity to preheat 250 thousand tons per year of scrap to 500 degrees celsius. Results showed that such a furnace would decrease energy consumption by 40 GWh per year and that it would take 5 years to return the investment. This study demonstrated that operating a solar furnace in the Iran Alloy Steel Company under Yazd climate conditions is feasible and would result in economic and environmental benefits.

10 CFR 431.72 - Definitions concerning commercial warm air furnaces.

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial warm air furnaces. 431... CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Warm Air Furnaces § 431.72 Definitions concerning commercial warm air furnaces. The following definitions apply for purposes of this subpart D, and of subparts...

Clinical tube weaning supported by hunger provocation in fully-tube-fed children.

Science.gov (United States)

Hartdorff, Caroline M; Kneepkens, C M Frank; Stok-Akerboom, Anita M; van Dijk-Lokkart, Elisabeth M; Engels, Michelle A H; Kindermann, Angelika

2015-04-01

Children with congenital malformations, mental retardation, and complex early medical history frequently have feeding problems. Although tube feeding is effective in providing the necessary energy and nutrients, it decreases the child's motivation to eat and may lead to oral aversion. In this study, we sought to confirm our previous results, showing that a multidisciplinary clinical hunger provocation program may lead to quick resumption of oral feeding. In a crossover study, 22 children of 9 to 24 months of age who were fully dependent on tube feeding were randomly assigned to one of two groups: group A, intervention group (2-week multidisciplinary clinical hunger provocation program); and group B, control group (4-week outpatient treatment by the same multidisciplinary team). Patients failing one treatment were reassigned to the other treatment group. Primary outcome measures were at least 75% orally fed at the conclusion of the intervention and fully orally fed and gaining weight 6 months after the intervention. In group A, 9/11 patients were successfully weaned from tube feeding (2 failures: 1 developed ulcerative colitis, 1 drop-out). In group B, only 1 patient was weaned successfully; 10/11 were reassigned to the clinical hunger provocation program, all being weaned successfully. Six months after the intervention, 1 patient had to resume tube feeding. In total, in the control group, 1/11 (9%) was weaned successfully as compared with 18/21 (86%) in the hunger provocation group (P hunger provocation is an effective short-term intervention for weaning young children from tube feeding.

Liquid-metal pin-fin pressure drop by correlation in cross flow

International Nuclear Information System (INIS)

Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

1994-01-01

The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed

TECHNOLOGICAL PECULIARITIES O F MELTING AND OUT-OF-FURNACE PROCESSING OF BALANCED STEELS IN CONDITIONS OF ELECTRIC FURNACE STEELMAKING AND CONTINUOUS CASTING

Directory of Open Access Journals (Sweden)

S. V. Terletski

2007-01-01

Full Text Available The technological peculiarities of melting and out-of-furnace processing of balanced steels in conditions of electric furnace steelmaking and continuous cast of RUP “BMZ” are considered.

Dispersive liquid-liquid microextraction combined with graphite furnace atomic absorption spectrometry

International Nuclear Information System (INIS)

Zeini Jahromi, Elham; Bidari, Araz; Assadi, Yaghoub; Milani Hosseini, Mohammad Reza; Jamali, Mohammad Reza

2007-01-01

Dispersive liquid-liquid microextraction (DLLME) technique was successfully used as a sample preparation method for graphite furnace atomic absorption spectrometry (GF AAS). In this extraction method, 500 μL methanol (disperser solvent) containing 34 μL carbon tetrachloride (extraction solvent) and 0.00010 g ammonium pyrrolidine dithiocarbamate (chelating agent) was rapidly injected by syringe into the water sample containing cadmium ions (interest analyte). Thereby, a cloudy solution formed. The cloudy state resulted from the formation of fine droplets of carbon tetrachloride, which have been dispersed, in bulk aqueous sample. At this stage, cadmium reacts with ammonium pyrrolidine dithiocarbamate, and therefore, hydrophobic complex forms which is extracted into the fine droplets of carbon tetrachloride. After centrifugation (2 min at 5000 rpm), these droplets were sedimented at the bottom of the conical test tube (25 ± 1 μL). Then a 20 μL of sedimented phase containing enriched analyte was determined by GF AAS. Some effective parameters on extraction and complex formation, such as extraction and disperser solvent type and their volume, extraction time, salt effect, pH and concentration of the chelating agent have been optimized. Under the optimum conditions, the enrichment factor 125 was obtained from only 5.00 mL of water sample. The calibration graph was linear in the rage of 2-20 ng L -1 with detection limit of 0.6 ng L -1 . The relative standard deviation (R.S.D.s) for ten replicate measurements of 20 ng L -1 of cadmium was 3.5%. The relative recoveries of cadmium in tap, sea and rivers water samples at spiking level of 5 and 10 ng L -1 are 108, 95, 87 and 98%, respectively. The characteristics of the proposed method have been compared with cloud point extraction (CPE), on-line liquid-liquid extraction, single drop microextraction (SDME), on-line solid phase extraction (SPE) and co-precipitation based on bibliographic data. Therefore, DLLME combined with

Multiphase flow modelling of furnace tapholes

OpenAIRE

Reynolds, Quinn G.; Erwee, Markus W.

2017-01-01

Pyrometallurgical furnaces of many varieties make use of tapholes in order to facilitate the removal of molten process material from inside the vessel. Correct understanding and operation of the taphole is essential for optimal performance of such furnaces. The present work makes use of computational fluid dynamics models generated using the OpenFOAM® framework in order to study flow behaviour in the taphole system. Single-phase large-eddy simulation models are used to quantify the discharge ...

The Automation Control System Design of Walking Beam Heating Furnace

Directory of Open Access Journals (Sweden)

Hong-Yu LIU

2014-10-01

Full Text Available Combining the transformation project of certain strip steel rolling production line, the techniques process of walking beam heating furnace was elaborated in this paper. The practical application of LOS-T18-2ZC1 laser detector was elaborated. The network communication model of walking beam heating furnace control system was designed. The realization method of production process automation control was elaborated. The entire automation control system allocation picture and PLC power distribution system picture of walking beam heating furnace were designed. Charge machine movement process was elaborated. Walking beam movement process was elaborated. Extractor movement process was elaborated. The hydraulic station of walking mechanism was elaborated. Relative control circuit diagram was designed. The control function of parallel shift motor, uplifted and degressive motor was elaborated. The control circuit diagram of parallel shift motor of charge machine and extractor of first heating furnace was designed. The control circuit diagram of uplifted and degressive motor of charge machine and extractor of first heating furnace was designed. The realization method of steel blank length test function was elaborated. The realization method of tracking and sequence control function of heating furnace field roller were elaborated. The design provides important reference base for enhancing walking beam heating furnace control level.

Modeling of aerodynamics in vortex furnace

Energy Technology Data Exchange (ETDEWEB)

Anufriev, I.; Krasinsky, D. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Inst. of Thermophysics; Salomatov, V.; Anikin, Y.; Sharypov, O. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Inst. of Thermophysics; Novosibirsk State Univ. (Russian Federation); Enkhjargal, Kh. [Mongol Univ. of Science and Technology, Ulan Bator (Mongolia)

2013-07-01

At present, the torch burning technology of pulverized-coal fuel in vortex flow is one of the most prospective and environmentally-friendly combustion technologies of low-grade coals. Appropriate organization of aerodynamics may influence stability of temperature and heat flux distributions, increase slag catching, and reduce toxic emissions. Therefore, from scientific point of view it is interesting to investigate aerodynamics in the devices aiming at justification of design and operating parameters for new steam generators with vortex furnace, and upgrade of existing boiler equipment. The present work is devoted to physical and mathematical modeling of interior aerodynamics of vortex furnace of steam generator of thermal power plants. Research was carried out on the air isothermal model which geometry was similar to one section of the experimental- industrial boiler TPE-427 of Novosibirsk TPS-3. Main elements of vortex furnace structure are combustion chamber, diffuser, and cooling chamber. The model is made from organic glass; on the front wall two rectangular nozzles (through which compressed air is injected) are placed symmetrically at 15 to the horizon. The Laser Doppler Velocimeter LAD-05 was used for non-contact measurement of vortex flow characteristics. Two velocity components in the XY-plane (in different cross- sections of the model) were measured in these experiments. Reynolds number was 3.10{sup 5}. Numerical simulation of 3-D turbulent isothermal flow was performed with the use of CFD package FLUENT. Detailed structure of the flow in vortex furnace model has been obtained in predictions. The distributions of main flow characteristics (pressure, velocity and vorticity fields, turbulent kinetic energy) are presented. The obtained results may be used at designing boilers with vortex furnace. Computations were performed using the supercomputer NKS-160.

46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or combustion... wall of a stayed furnace or combustion chamber, the defective portion of the plate shall be cut away...

Development and Validation of a 3-Dimensional CFB Furnace Model

Science.gov (United States)

Vepsäläinen, Arl; Myöhänen, Karl; Hyppäneni, Timo; Leino, Timo; Tourunen, Antti

At Foster Wheeler, a three-dimensional CFB furnace model is essential part of knowledge development of CFB furnace process regarding solid mixing, combustion, emission formation and heat transfer. Results of laboratory and pilot scale phenomenon research are utilized in development of sub-models. Analyses of field-test results in industrial-scale CFB boilers including furnace profile measurements are simultaneously carried out with development of 3-dimensional process modeling, which provides a chain of knowledge that is utilized as feedback for phenomenon research. Knowledge gathered by model validation studies and up-to-date parameter databases are utilized in performance prediction and design development of CFB boiler furnaces. This paper reports recent development steps related to modeling of combustion and formation of char and volatiles of various fuel types in CFB conditions. Also a new model for predicting the formation of nitrogen oxides is presented. Validation of mixing and combustion parameters for solids and gases are based on test balances at several large-scale CFB boilers combusting coal, peat and bio-fuels. Field-tests including lateral and vertical furnace profile measurements and characterization of solid materials provides a window for characterization of fuel specific mixing and combustion behavior in CFB furnace at different loads and operation conditions. Measured horizontal gas profiles are projection of balance between fuel mixing and reactions at lower part of furnace and are used together with both lateral temperature profiles at bed and upper parts of furnace for determination of solid mixing and combustion model parameters. Modeling of char and volatile based formation of NO profiles is followed by analysis of oxidizing and reducing regions formed due lower furnace design and mixing characteristics of fuel and combustion airs effecting to formation ofNO furnace profile by reduction and volatile-nitrogen reactions. This paper presents

Modelling of a one pass smoke tube boiler

DEFF Research Database (Denmark)

Karstensen, Claus M. S.; Sørensen, Kim

2004-01-01

A nonlinear state-space model with five states describing a one pass smoke tube boiler has been formulated. By means of mass- and energy-balance the model describes the dynamics of the Furnace, the Convection Zone and the Water/Steam Part and the three sub models are merged into an overall model....... The model is further linearized for use in a linear control design. The simulations have been carried out by means of MATLAB/SIMULINK and the models have been verified with measurements from a full scale boiler plant. Parameters in the model that are difficult to calculate have been estimated and the method...

Alkali-activated blast furnace slag-zeolite cements and concretes

International Nuclear Information System (INIS)

Rakhimov, R.; Rakhimova, N.

2012-01-01

The aim of this work has been the study of alkali-activated slag-zeolite cements and concretes based on them. Various compositions have been tested and some characteristics such as the compressive strength have been measured versus zeolite additions. A table lists the specific surface area and particle size distributions of different cements. The conclusions of the study are the following. First, alkali-activated slag cements and concretes based on them are effective for immobilization of radioactive wastes and the production of building structures, designed for high radiation load. Secondly, zeolite-containing mineral additions are able to increase the immobilization capacity and radiation resistance of alkali-activated blast furnace slag cements and concretes. Thirdly, the efficiency of different zeolite-containing additions - 10% to increase alkali-activated blast furnace slag-zeolite cement strength was established. It is with alkaline components of water-glass, sodium carbonate, sodium sulphate. Fourth, the effective way of introducing zeolite additions in alkali-activated blast furnace slag-zeolite cement is inter-grinding of the slag and addition. Increase in strength of alkali-activated blast furnace slag-zeolite cement stone is 40% higher than that of the stone of a mixture of separately milled components. Fifth, Alkali-activated blast furnace slag-zeolite cements with zeolite-containing additions with a compressive strength of 10.1 to 140 MPa; alkali-activated blast furnace slag-zeolite cements mortars with compressive strength from 35.2 to 97.7 MPa; alkali-activated blast furnace slag-zeolite cements concretes with compressive strength up to 84.5 MPa and frost resistant up to 800 cycles were obtained

Similarity of Ferrosilicon Submerged Arc Furnaces With Different Geometrical Parameters

Directory of Open Access Journals (Sweden)

Machulec B.

2017-12-01

Full Text Available In order to determine reasons of unsatisfactory production output regarding one of the 12 MVA furnaces, a comparative analysis with a furnace of higher power that showed a markedly better production output was performed. For comparison of ferrosilicon furnaces with different geometrical parameters and transformer powers, the theory of physical similarity was applied. Geometrical, electrical and thermal parameters of the reaction zones are included in the comparative analysis. For furnaces with different geometrical parameters, it is important to ensure the same temperature conditions of the reaction zones. Due to diverse mechanisms of heat generation, different criteria for determination of thermal and electrical similarity for the upper and lower reaction zones were assumed contrary to other publications. The parameter c3 (Westly was assumed the similarity criterion for the upper furnace zones where heat is generated as a result of resistive heating while the parameter J1 (Jaccard was assumed the similarity criterion for the lower furnace zones where heat is generated due to arc radiation.

Analysis for Eccentric Multi Canister Overpack (MCO) Drops at the Canister Storage Building (CSB) (CSB-S-0073)

Energy Technology Data Exchange (ETDEWEB)

TU, K.C.

1999-10-08

Multi-Canister Overpacks (MCOs) containing spent nuclear fuel (SNF) will be routinely handled at the Canister Storage Building (CSB) during fuel movement operations in the SNF Project. This analysis was performed to investigate the potential for damage from an eccentric accidental drop onto the standard storage tube, overpack tube, service station, or sample/weld station. Appendix D was added to the FDNW document to include the peer Review Comment Record & transmittal record.

Analysis for Eccentric Multi Canister Overpack (MCO) Drops at the Canister Storage Building (CSB) (CSB-S-0073)

International Nuclear Information System (INIS)

TU, K.C.

1999-01-01

Multi-Canister Overpacks (MCOs) containing spent nuclear fuel (SNF) will be routinely handled at the Canister Storage Building (CSB) during fuel movement operations in the SNF Project. This analysis was performed to investigate the potential for damage from an eccentric accidental drop onto the standard storage tube, overpack tube, service station, or sample/weld station. Appendix D was added to the FDNW document to include the peer Review Comment Record and transmittal record

Heat treatment of nuclear reactor pump part in integrated furnace facility

International Nuclear Information System (INIS)

Anon.

1983-01-01

A flexible heat treating system is meeting strict work specifications while accommodating the production flow pattern requirements and floor space needs of Advanced Metal Treating, Inc., Butler, Wis. Modular design and appropriate furnace configurations allow realization of the most efficient heat treat processing and energy use in a relatively small production area. The totally-integrated system (Pacemaker--manufactured by Lindberg, A Unit of General Signal, Chicago) consists of an electric integral-quench furnace with companion draw furnaces, washer unit and a material transfer car. With its one-side, inout configuration, the furnace operates with a minimum of drawing and washing equipment. The integral-quench furnace has a work chamber dimension of 30 by 48 by 30 inches (76.2 x 122 x 76.2 cm). The firm has two of these units, plus three in-out draw furnaces, one washer, one transfer car and two endothermic gas generators

The influence of near burner region aerodynamics on the formation and emission of nitrogen oxides in a pulverized coal-fired furnace

International Nuclear Information System (INIS)

Abbas, T.; Costen, P.; Lockwood, F.C.

1992-01-01

This paper reports that detailed measurements have been performed for two distinct pulverized-coal-fired burners in a large-scale laboratory furnace. Comparative in-flame data are archived and include gas temperature, O 2 , CO concentration, and an inventory of stable fuel nitrogen species and solids (HCN, NH 3 , N 2 O, NO, nitrogen release, mass flux, and particle burnout). A significant decrease in the NO concentration in the near burner region and a substantial decrease in the furnace exit values are observed when the central tube from a single annular orifice burner jet (normally the location of a gas or oil burner for light-up purposes) is replaced with a single central orifice burner jet of same cross-sectional area. The latter burner exhibits the delayed combustion phenomena normally associated with a tangentially fired system. The particle burnout remains unaffected due to the longer particles' residence time in the all-important oxygen lean internal recirculation zone

Comparison of possibilities the blast furnace and cupola slag utilization by concrete production

Directory of Open Access Journals (Sweden)

D. Baricová

2010-04-01

Full Text Available In process of pig iron and cast iron production secondary raw materials and industrial wastes are formed The most abundant secondaryproduct originating in these processes are furnace slag. Blast furnace slag and cupola furnace slag originates from melting of gangue parts of metal bearing materials, slag forming additions and coke ash. In general, slag are compounds of oxides of metallic and non-metallic elements, which form chemical compounds and solutions with each other and also contain small volume of metals, sulfides of metals and gases. Chemical, mineralogical and physical properties of slag determinate their utilisation in different fields of industry.The paper presents results from the research of the blast furnace and cupola furnace slag utilization in the concrete production. Pilotexperiments of the concrete production were performed, by that the blast furnace and cupola furnace slag with a fractions of 0–4mm;4–8mm; 8–16mm were used as a natural substitute. A cupola furnace slag and combination of the blast furnace and cupola furnace slagwere used in the experiments. The analysis results show that such concretes are suitable for less demanding applications.

Non-polluting steam generators with fluidized-bed furnaces

Energy Technology Data Exchange (ETDEWEB)

Brandes, H [Deutsche Babcock A.G., Oberhausen (Germany, F.R.)

1979-07-01

The author reports on a 35 MW steam generator with hard coal fluidized-bed furnace a planned 35 MW steam generator with flotation-dirt fluidized-bed furnace, and on planned steam generators for fluidized-bed firing of hard coal up to a steam power of about 200 MW.

Single-drop microextraction for the determination of manganese in seafood and water samples

International Nuclear Information System (INIS)

Lemos, V.A.; Vieira, U.S.

2013-01-01

We describe a method for single drop microextraction of manganese from fish, mollusk, and from natural waters using the reagent 1-(2-pyridylazo)-2-naphthol as the complexing agent and chloroform as the fluid extractor. After extraction, the analyte was directly submitted to graphite furnace electrothermal atomic absorption spectrometry. Once optimized, the method has a detection limit of 30 ng L -1 , a limit of quantification of 100 ng L -1 , and an enrichment factor of 16. Its accuracy was verified by applying the procedure to the following certified reference materials: apple leaves, spinach leaves, bovine liver, and mussel tissue. The procedure was also successfully applied to the determination of manganese in seafood and natural waters. (author)

Evaluation of different diameter arterial tubing and arterial cannulae in simulated neonatal/pediatric cardiopulmonary bypass circuits.

Science.gov (United States)

Wang, Shigang; Rosenthal, Tami; Kunselman, Allen R; Ündar, Akif

2015-01-01

The objective of this study is to evaluate three different diameters of arterial tubing and three diameters of arterial cannulae in terms of pressure drop, and hemodynamic energy delivery in simulated neonatal/pediatric cardiopulmonary bypass (CPB) circuits. The CPB circuit consisted of a Terumo Capiox Baby FX05 oxygenator (Terumo Corporation, Tokyo, Japan), arterial tubing (1/4 in, 3/16 in, or 1/8 in × 150 cm), and a Medtronic Bio-Medicus arterial cannula (8, 10, or 12 Fr; Medtronic, Inc., Minneapolis, MN, USA). The pseudo patient's pressure was maintained at 50 mm Hg. The circuit was primed using lactated Ringer's solution and heparinized packed human red blood cells (hematocrit 30%). Trials were conducted at different flow rates and temperatures (35 and 28°C). Flow and pressure data were collected using a custom-based data acquisition system. Using 8 Fr arterial cannula at 500 mL/min, small diameter arterial tubing generated higher circuit pressure (294.6 ± 0.1 mm Hg [1/8 in], 213.5 ± 0.5 mm Hg [3/16 in], 208.4 ± 0.4 mm Hg [1/4 in] at 35°C) and arterial line pressure drop (158.3 ± 0.1 mm Hg [1/8 in], 79.6 ± 0.1 mm Hg [3/16 in], 62.1 ± 0.1 mm Hg [1/4 in] at 35°C). Using 10 Fr arterial cannula at 1000 mL/min, pre-oxygenator pressures were 266.8 ± 0.2 mm Hg (3/16 in) and 248.0 ± 0.3 mm Hg (1/4 in); arterial line pressure drops were 111.6 ± 0.0 mm Hg (3/16 in) and 74.0 ± 0.1 mm Hg (1/4 in) at 35°C. When using 12 Fr arterial cannula at 1500 mL/min, preoxygenator pressures reached 324.4 ± 0.3 mm Hg (3/16 in) and 302.5 ± 0.4 mm Hg (1/4 in); arterial line pressure drops were 154.0 ± 0.1 mm Hg (3/16 in) and 92.0 ± 0.2 mm Hg (1/4 in) at 35°C. Pressure drops across arterial line tubing were main CPB circuit pressure drops. High flow rate, hypothermia, small diameter arterial tubing. and

Effects of fractal pore on coal devolatilization

Energy Technology Data Exchange (ETDEWEB)

Chen, Yongli; He, Rong [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Wang, Xiaoliang; Cao, Liyong [Dongfang Electric Corporation, Chengdu (China). Centre New Energy Inst.

2013-07-01

Coal devolatilization is numerically investigated by drop tube furnace and a coal pyrolysis model (Fragmentation and Diffusion Model). The fractal characteristics of coal and char pores are investigated. Gas diffusion and secondary reactions in fractal pores are considered in the numerical simulations of coal devolatilization, and the results show that the fractal dimension is increased firstly and then decreased later with increased coal conversions during devolatilization. The mechanisms of effects of fractal pores on coal devolatilization are analyzed.

Salvaging of service exposed cast alloy 625 cracker tubes of ammonia based Heavy Water Plants

International Nuclear Information System (INIS)

Kumar, Niraj; Misra, B.; Mahajan, M.P.; Mittra, J.; Sundararaman, M.; Chakravartty, J.K.

2006-01-01

In ammonia based heavy water plants, cracking of ammonia vapour, enriched in deuterium is carried out inside a cracker tube, packed with catalyst. These cracker tubes are made of alloy 625 (either wrought or cast) having dimensions of about 12.5 metres long, 88 mm outer diameter and 7.9 mm wall thickness. Seventy such tubes are housed in a typical ammonia cracker unit. The anticipated design life of such tube is 1,00,000 hrs. when operated at 720 degC based on creep as main degradation mechanism. Presently, these tubes are being operated at 680 degC skin temperature. Alloy 625 tubes are costly and normally not manufactured in India and are being imported. The cast alloy 625 cracker tubes have outlived their design life of 100,000 hrs. Therefore it has been decided to salvage the cast cracker tubes and extend the life further as it had already been done for wrought tubes. Similar to the earlier attempt of resolutionising of wrought alloy 625 tubes, efforts are in progress to salvage these cast tubes. In this study, cast tubes samples were subjected to solution-annealing treatment at two different temperatures, 1100degC and 1160degC respectively for two hrs. Mechanical properties along with the microstructure of the samples, which were resolutionized at 1160degC were comparable with that of virgin material. The 12.5 metres long cast alloy 625 cracker tubes will also be shortly solution-annealed in a specially designed resistance heating furnace after completing some more tests. (author)

An ice rink refrigeration system based on CO{sub 2} as secondary fluid in copper tubes

Energy Technology Data Exchange (ETDEWEB)

Shahzad, Khuram [Royal Inst. of Technology, Stockholrn (Sweden). Dept. of Energy Technology

2006-06-15

This report is a study of the use of copper tubes with CO{sub 2} as heat transfer fluid in ice rink applications. Copper tubes can be rolled rather easily up to the required length which decreases installation cost and simplifies the procedure. A test ice rink was built at IUC Ref Centre, Katrineholm with copper tubes. FEMLAB and EES are two softwares that were used for analysis. The comparison between 12.7 mm diameter copper tubes with and without plastic foil cover, 9.5 mm diameter copper tubes with and without plastic foil cover, 21.3 mm diameter steel pipes and 25 mm diameter plastic pipes is presented in the report. The reason to have plastic foil over copper tubes is to avoid the minor risk of chemical corrosion. Furthermore the foil serves as mechanical wear protection as well, which in this case could appear if rubbing would occur due to thermal expansion and contraction. It is found that 12.7 mm copper tube with plastic foil is good choice in terms of heat transfer. At rated heat flux of 100 W/m{sup 2} and with a pitch of 100 mm, it is 0.18 deg C better than 9.5 mm copper tube with plastic foil. This report includes the investigation which shows that there is no danger of movement of copper tubes inside the rink bed due to thermal expansion and contraction during operation. It also includes the comparison of average Friedel pressure drop model and average homogeneous pressure drop model with experimental results. Average Friedel pressure drop method gave good results. It predicted 20 to 25 % higher pressure drop at lower CR and about 60 % at higher CR than the experimental results for 120 meter long and 12.7 mm diameter copper tubes. 120 meter long copper tubes are good choice; as header can be placed on short side of the ice rink. It will reduce the header length and connections to half. FEMLAB modelling for conduction heat transfer gave good results and can be used as a tool for design and optimization. The optimization of the pitch of the copper tubes

Development and Field Trial of Dimpled-Tube Technology for Chemical Industry Process Heaters

Energy Technology Data Exchange (ETDEWEB)

Yaroslav Chudnovsky; Aleksandr Kozlov

2006-10-12

Most approaches to increasing heat transfer rates in the convection sections of gas-fired process heaters involve the incorporation of fins, baffles, turbulizers, etc. to increase either the heat transfer surface area or turbulence or both. Although these approaches are effective in increasing the heat transfer rates, this increase is invariably accompanied by an associated increase in convection section pressure drop as well as, for heaters firing ‘dirty’ fuel mixtures, increased fouling of the tubes – both of which are highly undesirable. GTI has identified an approach that will increase heat transfer rates without a significant increase in pressure drop or fouling rate. Compared to other types of heat transfer enhancement approaches, the proposed dimpled tube approach achieves very high heat transfer rates at the lowest pressure drops. Incorporating this approach into convection sections of chemical industry fired process heaters may increase energy efficiency by 3-5%. The energy efficiency increase will allow reducing firing rates to provide the required heating duty while reducing the emissions of CO2 and NOx.

Multi-fuel furnace. Demonstration project. Final rapport; Multibraendselsovn - Demonstrationsprojekt. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Dall Bentzen, J.

2012-06-15

It has been verified that the Dall Energy Furnace have unique features: - The furnace will accept biomass fuel with moisture content in range 20% to 60% and still keep the flue gas temperature within +-10 deg. Celsius (for pre-set temperature 900 to 975 deg. Celsius); - The ash quality from the furnace is very good with no excessive sintering and without carbon in the ash; - Flue gas dust content at the furnace exit is below 50 mg/Nm3, while the content of NO{sub x} and CO is below 175 mg/Nm3 and 20 mg/Nm3, respectively. The Dall Energy biomass furnace consists of two separate stages which are combined in a single aggregate: an updraft gasification process and a gas combustion process. As the furnace is refractory lined and as the furnace can operate at low excess air it is possible to burn biomass with water content above 60%. No mechanical parts are used at temperatures above 200 deg. Celsius. This provides a very rugged system. In the gasifier section a combustible gas is produced with a low velocity at the top of the gasifier bed. This gas is combusted to a flue gas with extremely low dust content. Also, the NO{sub x} and CO content is very low. The temperature of the flue gas at the exit is kept low by injecting water spray together with the secondary air. (Author)

Thermal design of horizontal tube boilers: numerical and experimental investigation

International Nuclear Information System (INIS)

Roser, Robert

1999-01-01

This work concerns the thermal design of kettle re-boilers. Current methods are highly inaccurate, regarded to the correlations for external heat transfer coefficient at one tube scale, as well as to two-phase flow modelling at boiler scale. The aim of this work is to improve these thermal design methods. It contains an experimental investigation with typical operating conditions of such equipment: an hydrocarbon (n-pentane) with low mass flux. This investigation has lead to characterize the local flow pattern through void fraction measurements and, from this, to develop correlations for void fraction, pressure drop and heat transfer coefficient. The approach is original, since the developed correlations are based on the liquid velocity at minimum cross section area between tubes, as variable characterizing the hydrodynamic effects on pressure drop and heat transfer coefficient. These correlations are shown to give much better results than those suggested up to now in the literature, which are empirical transpositions from methods developed for inside tube flows. Furthermore, the numerical code MC3D has been applied using the correlations developed in this work, leading to a modelization of the two-phase flow in the boiler, which is a significant progress compared to current simplified methods. (author) [fr

Heat transfer and pressure drop during flow boiling of R407C; Waermeuebergang und Druckverlust beim Stroemungssieden von R407C

Energy Technology Data Exchange (ETDEWEB)

Rollmann, Philipp; Spindler, Klaus [Stuttgart Univ. (DE). Inst. fuer Thermodynamik und Waermetechnik (ITW)

2011-10-15

The heat transfer and pressure drop during flow boiling of R407C in a horizontal microfin tube have been investigated. The measured heat transfer coefficient is compared with the correlations of Liu and Winterton as well as Cavallini et al. The measured pressure drop is compared with the correlations of Kuo and Wang as well as Mueller-Steinhagen and Heck. (orig.)

Minimizing shell-and-tube heat exchanger cost with genetic algorithms and considering maintenance

Energy Technology Data Exchange (ETDEWEB)

Wildi-Tremblay, P.; Gosselin, L. [Universite Laval, Quebec (Canada). Dept. de genie mecanique

2007-07-15

This paper presents a procedure for minimizing the cost of a shell-and-tube heat exchanger based on genetic algorithms (GA). The global cost includes the operating cost (pumping power) and the initial cost expressed in terms of annuities. Eleven design variables associated with shell-and-tube heat exchanger geometries are considered: tube pitch, tube layout patterns, number of tube passes, baffle spacing at the centre, baffle spacing at the inlet and outlet, baffle cut, tube-to-baffle diametrical clearance, shell-to-baffle diametrical clearance, tube bundle outer diameter, shell diameter, and tube outer diameter. Evaluations of the heat exchangers performances are based on an adapted version of the Bell-Delaware method. Pressure drops constraints are included in the procedure. Reliability and maintenance due to fouling are taken into account by restraining the coefficient of increase of surface into a given interval. Two case studies are presented. Results show that the procedure can properly and rapidly identify the optimal design for a specified heat transfer process. (author)

Effect of electropolishing on vacuum furnace design

Directory of Open Access Journals (Sweden)

Sutanwi Lahiri

2015-03-01

Full Text Available The use of thermal shields of materials having low emissivity in vacuum furnaces is well-known. However, the surface condition of the heat shields is one of the most important factors governing their efficiency as radiation resistances. The emissivity of the thermal shields dictates the power rating of the heaters in furnace design. The unpolished materials used in the heater tests showed poor performance leading to loss of a signi­ficant percentage of the input power. The present work deals with the refur­bishment of the radiation heat shields used in a furnace for heating graphite structure. The effect of refurbishment of the heat shields by the buffing and subsequently electro­polishing was found to improve the performance of the shields as heat reflectors. The com­position of the electrolyte was chosen in such a way that the large shields of Mo, Inconel and SS can be polished using the same reagents in different ratios. The present work deals with the development of a standard electropolishing procedure for large metallic sheets and subsequently qualifying them by roughness and emissivity measure­ments. The improvement noted in the shielding efficiency of the furnace in the subsequent runs is also discussed here.

Constructal design of finned tubes used in air-cooled heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Shokouhmand, Hossein; Mahjoub, Shoeib [University of Tehran, Tehran (Iran, Islamic Republic of); Salimpour, Mohammad Reza [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

2014-06-15

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

Constructal design of finned tubes used in air-cooled heat exchangers

International Nuclear Information System (INIS)

Shokouhmand, Hossein; Mahjoub, Shoeib; Salimpour, Mohammad Reza

2014-01-01

The present study documents the constructal design and optimization of finned tubes used in air-cooled heat exchangers. The considered tubes are equipped with annular fins. The aim is to minimize the overall thermal resistance by morphing the geometry. The geometrical and thermo-physical parameters considered are the number of fins, ratio of fin height to tube diameter, Stanton number, ratio of fin conductivity to air conductivity, ratio of in-tube fluid conductivity to air conductivity and dimensionless pressure drop. Two constraints are applied in the optimization process: fixed overall volume of heat exchanger and fixed volume fraction of fin material. It is found that there exist optimal values for the number and the height of fins. Moreover, the optimal heat transfer has an extremum in a special volume fraction of fin material.

A review of temperature measurement in the steel reheat furnace

International Nuclear Information System (INIS)

Martocci, A.P.; Mihalow, F.A.

1985-01-01

The incentive for conducting research and development on reheat furnaces is substantial; the domestic steel industry spent approximately one billion dollars on fuel in reheat furnaces in 1981. Bethlehem Steel Corp. spent /145 million of that total, and neither figure includes fuel consumed in soaking pits or annealing furnaces. If the authors set a goal to save 10% of these annual fuel costs, that translates into /100 million for the domestic steel industry and /14.5 million for Bethlehem Steel. These large sums of money are significant incentives. The purpose of this paper is to review the historical heating practices and equipment at steel reheat furnaces along with current practices and instrumentation

Lead scrap processing in rotary furnaces: a review

Energy Technology Data Exchange (ETDEWEB)

Rousseau, M

1987-01-01

Formerly, the lead scrap had been processed mainly in reverberatory and shaft furnaces or, even, in rotary furnaces (R.F.). The direct smelting of battery scrap entrains an expensive pollution control and high operating costs because of slag recirculation, coke consumption, losses in slag and matte. Nowadays, mechanized battery wrecking plants allow selective separation of casings and separators from metallic Pb (grids, poles, solders) as well as lead in non-metallic form (PbSO/sub 4/, PbO, PbO/sub 2/, contaminated with some Sb) frequently called paste. Because of their high performance and flexibility in metallurgical processing (melting, reducing, oxidizing and selective pouring) the R.F. supersedes the reverberatory furnace worldwide.

Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry

International Nuclear Information System (INIS)

Bentlin, Fabrina R.S.; Pozebon, Dirce; Mello, Paola A.; Flores, Erico M.M.

2007-01-01

A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO 3 ) 2 was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 μg g -1 of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

Mechanical design of ceramic beam tube braze joints for NOvA kicker magnets

Energy Technology Data Exchange (ETDEWEB)

Ader, C.R.; Reilly, R.E.; Wilson, J.H.; /Fermilab

2010-05-01

The NO?A Experiment will construct a detector optimized for electron neutrino detection in the existing NuMI neutrino beam. The NuMI beam line is capable of operating at 400 kW of primary beam power and the upgrade will allow up to 700 kW. Ceramic beam tubes are utilized in numerous kicker magnets in different accelerator rings at Fermi National Accelerator Laboratory. Kovar flanges are brazed onto each beam tube end, since kovar and high alumina ceramic have similar expansion curves. The tube, kovar flange, end piece, and braze foil alloy brazing material are stacked in the furnace and then brazed. The most challenging aspect of fabricating kicker magnets in recent years have been making hermetic vacuum seals on the braze joints between the ceramic and flange. Numerous process variables can influence the robustness of conventional metal/ceramic brazing processes. The ceramic-filler metal interface is normally the weak layer when failure does not occur within the ceramic. Differences between active brazing filler metal and the moly-manganese process will be discussed along with the applicable results of these techniques used for Fermilab production kicker tubes.

Control rod cluster drop time anomaly Guandong nuclear power station (Daya bay) and Electricite de France nuclear power stations (1450 MWe N4 Series)

International Nuclear Information System (INIS)

Olivera, J.J.; Naury, S.; Tricot, N.; Tran Dai, P.; Gama, J.M.

1996-01-01

The anomaly of control rod cluster drop time revealed at Guandong Nuclear Power Station in Daya Bay and in the Chooz B1 pilot unit for the N4 series, led to the replacement of the M1 type control rod cluster guide tubes with 1300 MWe PWR type guide tubes, adapted to the geometry of the Guandong reactors and the 1450 MWe reactors of the N4 series. The comparison of the drop times obtained with the 1300 MWe type control rod cluster guide 1300 MWe type control rod cluster guide tubes gave satisfactory results. These met the safety criterion for N4 series control rod cluster drop times (2.15 under hot shutdown conditions). The drop time tests which will be carried out in middle of and at the end of cycle 1 of Chooz B1 should make it possible to finally validate the solution already successfully implemented at Guandong. However, this anomaly has revealed the limits of representativeness of the experimental test loops with regard to the real reactor configuration. In view of this, it has been deemed necessary to ask Electricite de France to pursue its analysis both on the understanding of the phenomena which led to this anomaly and on the limits of the representativeness of the experimental test loops. (authors)

Contribution to the heat transfer analysis of substitute refrigerants in evaporator tubes with smooth or enhanced tube surfaces

Energy Technology Data Exchange (ETDEWEB)

Kattan, N

1997-12-31

The substitution of CFC refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, requests a good knowledge of heat transfer properties of substitute fluids. A new test facility has been built at the Laboratory for Industrial Energy Systems (LENI) to contribute to this international effort. It consists of two sets of concentric tubes allowing either annular or inside tube convective boiling with a counter current water flow heating to be studied. A new data base including heat transfer coefficients and pressure drop measurements for four new refrigerants (R123, R134A, R402A and R404A) and three older refrigerants (R11, R12 and R502) has been collected. Flow boiling measurements covered a broad range of mass velocities, vapor qualities and heat fluxes. Some of the tests included plain tubes and others enhanced surface tubes (microfilms from Wieland) in horizontal and vertical orientations. An improved Wilson plot technique, that covers both the transition and turbulent flow regimes of the water flowing in the annular channel for the inside tube boiling tests, is proposed to overcome the severe limitations of conventional Wilson plots, to improve accuracy and to facilitate data processing. Mean flow boiling heat transfer coefficients were measured for R12 and R134A evaporating inside a horizontal plain tube and for R11 and R123 evaporating inside a horizontal plain tube. Local flow boiling heat transfer coefficients were measured for : R134A, R123, R404A and R502 evaporating inside a horizontal plain tube, for R134A and R123 evaporating inside a horizontal microfin tube and for R134 evaporating inside a vertical microfin tube. In addition microfin heat transfer augmentation relative to plain tube test data was investigated. The measured heat transfer coefficients were compared to different existing inside tube flow boiling correlations. (author) figs., tabs., refs.

Determination of trace amounts of cadmium in zirconium and its alloys by graphite furnace AAS

International Nuclear Information System (INIS)

Takashima, Kyoichiro; Toida, Yukio

1994-01-01

Trace amount of cadmium in zirconium and its alloys was determined by graphite furnace atomic absorption spectrometry (GF-AAS) after ion exchange separation. A 2g chip sample was decomposed with 20ml of hydrofluoric acid (1+9) and a few drops of nitric acid. A trace amount of cadmium was separated from zirconium by strongly acidic cation-exchange resin (MCI GEL CK 08P) using 50ml of hydrochloric acid as an eluent. The solution was gently evaporated to dryness on an electric hot plate heater and under an infrared lamp. The residue was dissolved in 1ml of nitric acid (1+14) and diluted to 10ml in a volumetric glass flask with distilled water. Ten microliters of this solution was injected into a graphite furnace and then atomized at 2200degC for 4s in argon at a flow rate of 3.0l/min. Acids used in the analytical procedure were purified by azeotropic distillation and cation-exchange resin. The limit of determination (3σ BK ) for cadmium was 0.5ngCd/g and the relative standard deviation (RSD) at 1ngCd/g level was less than 20% for the GF-AAS. The accuracy of this technique was confirmed by NIST SRM 1643b (trace elements in water). (author)

Loss on Ignition Furnace Acceptance and Operability Test Procedure

Energy Technology Data Exchange (ETDEWEB)

JOHNSON, D.C.

2000-06-01

The purpose of this Acceptance Test Procedure and Operability Test Procedure (ATP/OTP)is to verify the operability of newly installed LOI equipment, including a model 1608FL CM{trademark} Furnace, a dessicator, and balance. The operability of the furnace will be verified. The arrangement of the equipment placed in Glovebox 157-3/4 to perform Loss on Ignition (LOI) testing on samples supplied from the Thermal Stabilization line will be verified. In addition to verifying proper operation of the furnace, this ATP/OTP will also verify the air flow through the filters, verify a damper setting to establish and maintain the required differential pressure between the glovebox and the room pressure, and test the integrity of the newly installed HEPA filter. In order to provide objective evidence of proper performance of the furnace, the furnace must heat 15 crucibles, mounted on a crucible rack, to 1000 C, according to a program entered into the furnace controller located outside the glovebox. The glovebox differential pressure will be set to provide the 0.5 to 2.0 inches of water (gauge) negative pressure inside the glovebox with an airflow of 100 to 125 cubic feet per minute (cfm) through the inlet filter. The glovebox inlet Glfilter will he flow tested to ensure the integrity of the filter connections and the efficiency of the filter medium. The newly installed windows and glovebox extension, as well as all disturbed joints, will be sonically tested via ultra probe to verify no leaks are present. The procedure for DOS testing of the filter is found in Appendix A.

Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

Energy Technology Data Exchange (ETDEWEB)

Vidal, Lorena [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Domini, Claudia E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Grane, Nuria [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Psillakis, Elefteria [Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania, Crete (Greece); Canals, Antonio [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain)]. E-mail: a.canals@ua.es

2007-05-29

A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 {mu}L microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low {mu}g L{sup -1} range varying between 0.016 and 0.039 {mu}g L{sup -1}. Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction.

Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

International Nuclear Information System (INIS)

Vidal, Lorena; Domini, Claudia E.; Grane, Nuria; Psillakis, Elefteria; Canals, Antonio

2007-01-01

A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 μL microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low μg L -1 range varying between 0.016 and 0.039 μg L -1 . Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction

Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces; La metalurgia del mercurio en Almaden: desde los hornos de aludeles a los hornos Pacific

Energy Technology Data Exchange (ETDEWEB)

Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

2014-07-01

This paper shows the different types of furnaces for roasting cinnabar, used in the metallurgy of quicksilver over the centuries of exploitation of the Almaden Mines (Spain). Some of these techniques are part of our industrial heritage. They have contributed to name UNESCO World Heritage Site the vast technological legacy of these mines recently. This research contributes to close the long way of metallurgical activity from aludel furnaces until Pacif furnaces, first and lasted technology to produce on an industrial scale. It is delved into the most relevant aspects having to do with the type, evolution and number of furnaces existing on each of the periods. (Author)

Drop jumping. II. The influence of dropping height on the biomechanics of drop jumping

NARCIS (Netherlands)

Bobbert, M F; Huijing, P A; van Ingen Schenau, G J

In the literature, athletes preparing for explosive activities are recommended to include drop jumping in their training programs. For the execution of drop jumps, different techniques and different dropping heights can be used. This study was designed to investigate for the performance of bounce

Design of a rotating-hearth furnace

Energy Technology Data Exchange (ETDEWEB)

Behrens, H A [LOI Industrieofenanlagen G.m.b.H., Essen (Germany, F.R.)

1979-09-01

Part I of this paper is intended to present a review of the theory of heating round stock of a length considerably exceeding the diameter. It is permissible to neglect heating from the ends of the cylinders. With short and thick ingots as used in pilgrim mills, for instance, such simplification is not possible. The method for calculating the waste gas temperature can also be used for the remaining furnace sections provided certain conditions are allowed for and computational procedures observed. Part II of the paper will deal with this and with the major design features of rotating-hearth furnaces.

Method for confirming flow pattern of gas-water flow in horizontal tubes under rolling state

International Nuclear Information System (INIS)

Luan Feng; Yan Changqi

2008-01-01

An experimental study on the flow patterns of gas-water flow was carried out in horizontal tubes under rolling state. It was found that the pressure drop of two phase flow was with an obvious periodical characteristic. The flow pattern of the gas-water flow was distinguished according to the characteristics of the pressure drop in this paper. It was proved that the characteristics of the pressure drop can distinguish the flow pattern of gas-water flow correctly through comparing with the result of careful observation and high speed digital camera. (authors)

Improvement of life and NO{sub x} emission of radiant tube heating system by elastic-plastic creep analysis; Dansosei kuripu kaiseki ni yoru hosha dennetsukan kanetsu shisutemu no jumyo to NO{sub x} haishutsuryo no kaizen

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Tsuguhiko; Nuta, Kunihiro [Kawasaki Steel Corp., Okayama, (Japan). Mizushima Warks

1999-03-10

The radiant tube heating system has been widely applied to the furnaces which require isolation of the heating atmosphere from the combustion atmosphere. However, the conventional system has a short life and it is difficult to reduce NO{sub x} emission when it is used at a high furnace temperature under high combustion load, because the fuel is burned in a small space. In order to solve this problem, we have studied the cause of radiant tube life depends on the uniformity of the temperature distribution along the radiant tube. We have developed a new burner using a two-stage combustion method with exhaust gas self-recirculation. As a result, the file of the new system has been increased by a factor of two or more, and NO{sub x} emission has been reduced by 20 % from previous levels. This paper presents an outline of the elastic-plastic creep analysis and the new burner, and describes the effect of its use on system life. (author)

First drop dissimilarity in drop-on-demand inkjet devices

International Nuclear Information System (INIS)

Famili, Amin; Palkar, Saurabh A.; Baldy, William J. Jr.

2011-01-01

As inkjet printing technology is increasingly applied in a broader array of applications, careful characterization of its method of use is critical due to its inherent sensitivity. A common operational mode in inkjet technology known as drop-on-demand ejection is used as a way to deliver a controlled quantity of material to a precise location on a target. This method of operation allows ejection of individual or a sequence (burst) of drops based on a timed trigger event. This work presents an examination of sequences of drops as they are ejected, indicating a number of phenomena that must be considered when designing a drop-on-demand inkjet system. These phenomena appear to be driven by differences between the first ejected drop in a burst and those that follow it and result in a break-down of the linear relationship expected between driving amplitude and drop mass. This first drop, as quantified by high-speed videography and subsequent image analysis, can be different in morphology, trajectory, velocity, and volume from subsequent drops within a burst. These findings were confirmed orthogonally by both volume and mass measurement techniques which allowed quantitation down to single drops.

Open fireplace furnace as an adequate heating system

Energy Technology Data Exchange (ETDEWEB)

Terbrack, E.

The fireplace furnace is a furnace for the open fireplace. It is connected to the existing fuel-oil or gas central heating and is used for house heating and warm water preparation when the fire in the fireplace is on. It combines the romanticism of the open fireplace with the necessity of saving fuel oil and gas, ensuring heat supply.

Zone modelling of the thermal performances of a large-scale bloom reheating furnace

International Nuclear Information System (INIS)

Tan, Chee-Keong; Jenkins, Joana; Ward, John; Broughton, Jonathan; Heeley, Andy

2013-01-01

This paper describes the development and comparison of a two- (2D) and three-dimensional (3D) mathematical models, based on the zone method of radiation analysis, to simulate the thermal performances of a large bloom reheating furnace. The modelling approach adopted in the current paper differs from previous work since it takes into account the net radiation interchanges between the top and bottom firing sections of the furnace and also allows for enthalpy exchange due to the flows of combustion products between these sections. The models were initially validated at two different furnace throughput rates using experimental and plant's model data supplied by Tata Steel. The results to-date demonstrated that the model predictions are in good agreement with measured heating profiles of the blooms encountered in the actual furnace. It was also found no significant differences between the predictions from the 2D and 3D models. Following the validation, the 2D model was then used to assess the impact of the furnace responses to changing throughput rate. It was found that the potential furnace response to changing throughput rate influences the settling time of the furnace to the next steady state operation. Overall the current work demonstrates the feasibility and practicality of zone modelling and its potential for incorporation into a model based furnace control system. - Highlights: ► 2D and 3D zone models of large-scale bloom reheating furnace. ► The models were validated with experimental and plant model data. ► Examine the transient furnace response to changing the furnace throughput rates. ► No significant differences found between the predictions from the 2D and 3D models.

Blast furnace hearth lining: post mortem analysis

International Nuclear Information System (INIS)

Almeida, Bruno Vidal de; Vernilli Junior, Fernando

2017-01-01

The main refractory lining of blast furnace hearth is composed by carbon blocks that operates in continuous contact with hot gases, liquid slag and hot metal, in temperatures above 1550 deg C for 24 hours a day. To fully understand the wear mechanism that acts in this refractory layer system it was performed a Post Mortem study during the last partial repair of this furnace. The samples were collected from different parts of the hearth lining and characterized using the following techniques: Bulk Density and Apparent Porosity, X-Ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy with Energy-dispersive X-Ray Spectroscopy. The results showed that the carbon blocks located at the opposite side of the blast furnace tap hole kept its main physicochemical characteristics preserved even after the production of 20x10"6 ton of hot metal. However, the carbon blocks around the Tap Hole showed infiltration by hot metal and slag and it presents a severe deposition of zinc and sulfur over its carbon flakes. The presence of these elements is undesired because it reduces the physic-chemical stability of this refractory system. This deposition found in the carbon refractory is associated with impurities present in the both coke and the sinter feed used in this blast furnace in the last few years. (author)

Blast furnace hearth lining: post mortem analysis

Energy Technology Data Exchange (ETDEWEB)

Almeida, Bruno Vidal de; Vernilli Junior, Fernando, E-mail: bva@usp.br [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia; Neves; Elton Silva; Silva, Sidiney Nascimento [Companhia Siderugica Nacional (CSN), Rio de Janeiro, RJ (Brazil)

2017-05-15

The main refractory lining of blast furnace hearth is composed by carbon blocks that operates in continuous contact with hot gases, liquid slag and hot metal, in temperatures above 1550 deg C for 24 hours a day. To fully understand the wear mechanism that acts in this refractory layer system it was performed a Post Mortem study during the last partial repair of this furnace. The samples were collected from different parts of the hearth lining and characterized using the following techniques: Bulk Density and Apparent Porosity, X-Ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy with Energy-dispersive X-Ray Spectroscopy. The results showed that the carbon blocks located at the opposite side of the blast furnace tap hole kept its main physicochemical characteristics preserved even after the production of 20x10{sup 6} ton of hot metal. However, the carbon blocks around the Tap Hole showed infiltration by hot metal and slag and it presents a severe deposition of zinc and sulfur over its carbon flakes. The presence of these elements is undesired because it reduces the physic-chemical stability of this refractory system. This deposition found in the carbon refractory is associated with impurities present in the both coke and the sinter feed used in this blast furnace in the last few years. (author)

Experimental study of thermal–hydraulic performance of cam-shaped tube bundle with staggered arrangement

International Nuclear Information System (INIS)

Bayat, Hamidreza; Lavasani, Arash Mirabdolah; Maarefdoost, Taher

2014-01-01

Highlights: • Thermal–hydraulic performance of a non-circular tube bundle has been investigated experimentally. • Tubes were mounted in staggered arrangement with two longitudinal pitch ratios 1.5 and 2. • Drag coefficient and Nusselt number of tubes in second row was measured. • Friction factor of this tube bundle is lower than circular tube bundle. • Thermal–hydraulic performance of this tube bundle is greater than circular tube bundle. - Abstract: Flow and heat transfer from cam-shaped tube bank in staggered arrangement is studied experimentally. Tubes were located in test section of an open loop wind tunnel with two longitudinal pitch ratios 1.5 and 2. Reynolds number varies in range of 27,000 ⩽ Re D ⩽ 42,500 and tubes surface temperature is between 78 and 85 °C. Results show that both drag coefficient and Nusselt number depends on position of tube in tube bank and Reynolds number. Tubes in the first column have maximum value of drag coefficient, while its Nusselt number is minimum compared to other tubes in tube bank. Moreover, pressure drop from this tube bank is about 92–93% lower than circular tube bank and as a result thermal–hydraulic performance of this tube bank is about 6 times greater than circular tube bank

Innovation in electric arc furnaces scientific basis for selection

CERN Document Server

Toulouevski, Yuri N

2013-01-01

This book equips a reader with knowledge necessary for critical analysis of  innovations in electric arc furnaces and helps to select the most effective ones and for their successful implementation. The book also covers general issues related to history of development, current state and prospects of steelmaking in Electric Arc Furnaces. Therefore, it can be useful for everybody who studies metallurgy, including students of colleges and universities. The modern concepts of mechanisms of Arc Furnace processes are are discussed in the book at the level sufficient to solve practical problems: To help readers lacking knowledge required in the field of heat transfer as well as hydro-gas dynamics, it contains several chapters which provide the required minimum of information in these fields of science. In order to better assess different innovations, the book describes experience of the application of similar innovations in open-hearth furnaces and oxygen converters. Some promising ideas on key issues regarding int...

Experimental Heat Transfer, pressure drop, and Flow Visualization of R-134a in Vertical Mini/Micro Tubes

OpenAIRE

Owhaib, Wahib

2007-01-01

For the application of minichannel heat exchangers, it is necessary to have accurate design tools for predicting heat transfer and pressure drop. Until recently, this type of heat exchangers was not well studied, and in the scientific literature there were large discrepancies between results reported by different investigators. The present thesis aims to add to the knowledge of the fundamentals of single- and two-phase flow heat transfer and pressure drop in narrow channels, thereby aiding in...

Efficient use of power in electric arc furnaces

Energy Technology Data Exchange (ETDEWEB)

Freeman, E R; Medley, J E

1978-02-01

The maximum transfer of electric energy to the metal in an arc furnace depends on the length of arc and the impedance of the electrical supply system from the generators to the arc itself. The use of directly-reduced sponge iron by continuous feeding results in long periods of flat-bath operation, when it is particularly important to keep a short high-current arc to get the heat into the metal rather than to the refractories, which would suffer excessive wear. By reference to a 125 ton furnace, a method of assessing the optimum operating currents and power factors and the effects of differing power-supply systems is illustrated. The importance of a low-impedance power system is illustrated, and the possibility of being unable to use the maximum furnace power without excessive refractory wear is noted. The particular problems of connecting arc-furnace loads to electrical supply systems are reviewed, and consideration is given to the problem of voltage flicker. The use of compensators is discussed with reference to existing installations, in which strong supplies from the supply-authority system are not economically available. The furnace operating characteristics, which indicate the optimum points of working, have to be checked on commissioning, and the test procedures are outlined. The optimum points for each type of charge and steel can be assessed only during their actual production. The importance of proper recording of relevant data is stressed, and reference is made to the use of computers and automatic power-input controllers.

Continuous austempering fluidized bed furnace. Final report

Energy Technology Data Exchange (ETDEWEB)

Srinivasan, M.N. [Lamar Univ., Beaumont, TX (United States). Dept. of Mechanical Engineering

1997-09-23

The intended objective of this project was to show the benefits of using a fluidized bed furnace for austenitizing and austempering of steel castings in a continuous manner. The division of responsibilities was as follows: (1) design of the fluidized bed furnace--Kemp Development Corporation; (2) fabrication of the fluidized bed furnace--Quality Electric Steel, Inc.; (3) procedure for austempering of steel castings, analysis of the results after austempering--Texas A and M University (Texas Engineering Experiment Station). The Department of Energy provided funding to Texas A and M University and Kemp Development Corporation. The responsibility of Quality Electric Steel was to fabricate the fluidized bed, make test castings and perform austempering of the steel castings in the fluidized bed, at their own expense. The project goals had to be reviewed several times due to financial constraints and technical difficulties encountered during the course of the project. The modifications made and the associated events are listed in chronological order.

Assessing energy efficiency of electric car bottom furnaces intended for thermal energization of minerals

Science.gov (United States)

Nizhegorodov, A. I.

2017-01-01

The paper deals with a new concept of electric furnaces for roasting and thermal energization of vermiculite and other minerals with vibrational transportation of a single-layer mass under constant thermal field. The paper presents performance calculation and comparative assessment of energy data for furnaces of different modifications: flame and electric furnaces with three units, furnaces with six units and ones with series-parallel connection of units, and furnaces of new concept.

Loss on Ignition Furnace Acceptance and Operability Test Procedure

International Nuclear Information System (INIS)

JOHNSTON, D.C.

2000-01-01

The purpose of this Acceptance Test Procedure and Operability Test Procedure (ATP/OTP)is to verify the operability of newly installed Loss on Ignition (LOI) equipment, including a model 1608FL CMTM Furnace, a dessicator, and balance. The operability of the furnace will be verified. The arrangement of the equipment placed in Glovebox 157-3/4 to perform LOI testing on samples supplied from the Thermal Stabilization line will be verified. In addition to verifying proper operation of the furnace, this ATP/OTP will also verify the air flow through the filters, verify a damper setting to establish and maintain the required differential pressure between the glovebox and the room pressure, and test the integrity of the newly installed HEPA filter. In order to provide objective evidence of proper performance of the furnace, the furnace must heat 15 crucibles, mounted on a crucible rack, to 1000 C, according to a program entered into the furnace controller located outside the glovebox. The glovebox differential pressure will be set to provide the 0.5 to 2.0 inches of water (gauge) negative pressure inside the glovebox with an expected airflow of 100 to 125 cubic feet per minute (cfm) through the inlet filter. The glovebox inlet G1 filter will be flow tested to ensure the integrity of the filter connections and the efficiency of the filter medium. The newly installed windows and glovebox extension, as well as all disturbed joints, will be sonically tested via ultra probe to verify no leaks are present. The procedure for DOS testing of the filter is found in Appendix A

Experimental investigation of a draft tube spouted bed for effects of geometric parameters on operation

DEFF Research Database (Denmark)

Azizaddini, Seyednezamaddin; Lin, Weigang; Dam-Johansen, Kim

2016-01-01

Experiments are performed in a draft tube spouted bed (DTSB) to investigate effects of the operating conditions and the geometric parameters on the hydrodynamics. Geometry parameters, such as heights of the entrained zone, draft tube inner diameter, inner angle of the conical section were studied....... Increasing the draft tube inner diameter, sharper inner angle of the conical section and higher height of entrained zone increase the internal solid circulation rate and the pressure drop. Even though, for all different configurations, higher gas feeding rate leads to higher internal solid circulation rate...

Development of a cylindrical gas-fired furnace for reycling ...

African Journals Online (AJOL)

This study presents the development of a cylindrical gas-fired furnace, which could be used for recycling aluminum in small-scale foundries in Nigeria. The crucible, combustion chamber, suspension shaft and bearings were appropriately sized. The furnace chamber was 410 mm high and 510 mm diameter and had a ...

Application of roof radiant burners in large pusher-type furnaces

Directory of Open Access Journals (Sweden)

A. Varga

2009-07-01

Full Text Available The paper deals with the application of roof flat-flame burners in the pusher-type steel slab reheating furnaces, after furnace reconstruction and replacement of conventional torch burners, with the objective to increase the efficiency of radiative heat transfer from the refractory roof to the charge. Based on observations and on measurements of the construction and process parameters under operating conditions, the advantages and disadvantages of indirectly oriented radiant heat transfer are analysed in relation to the heat transfer in classically fired furnaces.

Unique furnace system for high-energy-neutron experiments

International Nuclear Information System (INIS)

Panayotou, N.F.; Green, D.R.; Price, L.S.

1982-03-01

The low flux of high energy neutron sources requires optimum utilization of the available neutron field. A furnace system has been developed in support of the US DOE fusion materials program which meets this challenge. Specimens positioned in two temperature zones just 1 mm away from the outside surface of a neutron window in the furnace enclosure can be irradiated simultaneously at two independent, isothermal (+- 1 0 C) temperatures. The temperature difference between these closely spaced isothermal zones is controllable from 0 to 320 0 C and the maximum temperature is 400 0 C. The design of the system also provides a controlled specimen environment, rapid heating and cooling and easy access to heaters and thermocouples. This furnace system is in use at the Rotating Target Neutron Source-II of Lawrence Livermore National Laboratory

Handling of corn stover bales for combustion in small and large furnaces

Energy Technology Data Exchange (ETDEWEB)

Morissette, R.; Savoie, P.; Villeneuve, J. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada)

2010-07-01

This paper reported on a study in which dry corn stover was baled and burned in 2 furnaces in the province of Quebec. Small and large rectangular bale formats were considered for direct combustion. The first combustion unit was a small 500,000 BTU/h dual chamber log wood furnace located at a hay growing farm in Neuville, Quebec. The heat was initially transferred to a hot water pipe system and then transferred to a hot air exchanger to dry hay bales. The small stover bales were placed directly into the combustion furnace. The low density of the bales compared to log wood, required filling up to 8 times more frequently. Stover bales produced an average of 6.4 per cent ash on a DM basis and required an automated system for ash removal. Combustion gas contained levels of particulate matter greater than 1417 mg/m{sup 3}, which is more than the local acceptable maximum of 600 mg/m{sup 3} for combustion furnaces. The second combustion unit was a high capacity 12.5 million BTU/h single chamber furnace located in Saint-Philippe-de-neri, Quebec. It was used to generate steam for a feed pellet mill. Large corn stover bales were broken up and fed on a conveyor and through a screw auger to the furnace. The stover was light compared to the wood chips used in this furnace. For mechanical reasons, the stover could not be fed continuously to the furnace.

Measure Guideline. High Efficiency Natural Gas Furnaces

Energy Technology Data Exchange (ETDEWEB)

Brand, L. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States); Rose, W. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)

2012-10-01

This measure guideline covers installation of high-efficiency gas furnaces, including: when to install a high-efficiency gas furnace as a retrofit measure; how to identify and address risks; and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

Acoustic Levitator With Furnace And Laser Heating

Science.gov (United States)

Barmatz, Martin B.; Stoneburner, James D.

1991-01-01

Acoustic-levitation apparatus incorporates electrical-resistance furnace for uniform heating up to temperature of about 1,000 degrees C. Additional local heating by pair of laser beams raise temperature of sample to more than 1,500 degrees C. High temperature single-mode acoustic levitator generates cylindrical-mode accoustic resonance levitating sample. Levitation chamber enclosed in electrical-resistance furnace. Infrared beams from Nd:YAG laser provide additional local heating of sample. Designed for use in containerless processing of materials in microgravity or in normal Earth gravity.

Immersed single-drop microextraction interfaced with sequential injection analysis for determination of Cr(VI) in natural waters by electrothermal-atomic absorption spectrometry

International Nuclear Information System (INIS)

Pena, Francisco; Lavilla, Isela; Bendicho, Carlos

2008-01-01

Single-drop microextraction (SDME) and sequential injection analysis have been hyphenated for ultratrace metal determination by Electrothermal-Atomic Absorption Spectrometry (ETAAS). The novel method was targeted on extraction of the Cr(VI)-APDC chelate and encompasses the potential of SDME as a miniaturized and virtually solvent-free preconcentration technique, the ability of sequential injection analysis to handle samples and the versatility of furnace autosamplers for introducing microliter samples in ETAAS. The variables influencing the microextraction of Cr(VI) onto an organic solvent drop, i.e., type of organic solvent, microextraction time, stirring rate of the sample solution, drop volume, immersion depth of the drop, salting-out effect, temperature of the sample, concentration of the complexing agent and pH of the sample solution were fully investigated. For a 5 and 20 min microextraction time, the preconcentration factors were 20 and 70, respectively. The detection limit was 0.02 μg/L of Cr(VI) and the repeatability expressed as relative standard deviation was 7%. The SDME-SIA-ETAAS technique was validated against BCR CRM 544 (lyophilized solution) and applied to ultrasensitive determination of Cr(VI) in natural waters

Immersed single-drop microextraction interfaced with sequential injection analysis for determination of Cr(VI) in natural waters by electrothermal-atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Pena, Francisco; Lavilla, Isela [Departamento de Quimica Analitica y Alimentaria, Area de Quimica Analitica, Facultad de Quimica, Universidad de Vigo, Campus As Lagoas-Marcosende, s/n, 36310 Vigo (Spain); Bendicho, Carlos [Departamento de Quimica Analitica y Alimentaria, Area de Quimica Analitica, Facultad de Quimica, Universidad de Vigo, Campus As Lagoas-Marcosende, s/n, 36310 Vigo (Spain)], E-mail: bendicho@uvigo.es

2008-04-15

Single-drop microextraction (SDME) and sequential injection analysis have been hyphenated for ultratrace metal determination by Electrothermal-Atomic Absorption Spectrometry (ETAAS). The novel method was targeted on extraction of the Cr(VI)-APDC chelate and encompasses the potential of SDME as a miniaturized and virtually solvent-free preconcentration technique, the ability of sequential injection analysis to handle samples and the versatility of furnace autosamplers for introducing microliter samples in ETAAS. The variables influencing the microextraction of Cr(VI) onto an organic solvent drop, i.e., type of organic solvent, microextraction time, stirring rate of the sample solution, drop volume, immersion depth of the drop, salting-out effect, temperature of the sample, concentration of the complexing agent and pH of the sample solution were fully investigated. For a 5 and 20 min microextraction time, the preconcentration factors were 20 and 70, respectively. The detection limit was 0.02 {mu}g/L of Cr(VI) and the repeatability expressed as relative standard deviation was 7%. The SDME-SIA-ETAAS technique was validated against BCR CRM 544 (lyophilized solution) and applied to ultrasensitive determination of Cr(VI) in natural waters.

Numerical investigation on a novel shell-and-tube heat exchanger with plate baffles and experimental validation

International Nuclear Information System (INIS)

Yang, Jie; Liu, Wei

2015-01-01

Highlights: • A novel shell-and-tube heat exchanger with plate baffles is proposed. • Heat transfer and pressure drop of computational calculations are studied. • Experimental method is carried out to verify the modeling approach. • Path lines, temperature field and pressure field are analyzed. - Abstract: A novel shell-and-tube heat exchanger with new plate baffles is proposed. It is numerically investigated in comparison with a shell-and-tube heat exchanger with rod baffles. Commercial softwares FLUENT 6.3 and GAMBIT 2.3 are adopted for modeling and computational calculations. The modeling approach is verified with experimental approach. The shell-side results of heat transfer, flow performance, and comprehensive performance are analyzed. The Nusselt number for the plate baffles heat exchanger is around 128–139% of that for the rod baffles heat exchanger. The pressure drop for the novel one is about 139–147% of that for the rod baffles heat exchanger. Overall, the novel plate baffles heat exchanger illustrates evidently higher comprehensive performance (115–122%) than the rod baffles one. The temperature field, pressure field, and path lines are analyzed to demonstrate the advantage of the novel shell-and-tube heat exchanger

Stress relief treatment of Alloy 600 steam generator tubing

International Nuclear Information System (INIS)

Rooyen, D. van; Cragnolino, C.

1994-01-01

The intergranular stress corrosion cracking (IGSCC) of Alloy 600 tubing in the primary side of operating steam generators is the subject of this investigation. The objective of the program was to examine the feasibility of heat treatment to alleviate the IGSCC problem. In addition to this, tests were also performed to examine the IGSCC susceptibility of nuclear grade Alloy 600 tubing obtained from various sources. Examination of temperature-time combinations that may hold potential for improved IGSCC resistance of the transition regions of tubes expanded into tube sheet holes was done. The combinations fall in two categories. One is of short duration and relatively high temperature, where induction is the best method of heating because the treatment only lasts from some tens of seconds to a few minutes. The other is carried out in a lower temperature range and lasts for several hours. This latter combination of temperatures and times is considered for the so-called global heat treatment of entire tube sheet. To assess the effect of these treatments, reverse U-bend testing in high purity deaerated water containing an overpressure of hydrogen was employed and several heats of Alloy 600 were compared in tests at 365 degrees C, which is well above actual operating temperatures of steam generators, but provides an accelerated test procedure. Results of furnace heating in the range of 550-610 degrees C indicated improvement in IGSCC resistance, with best performance after a heat treatment at 610 degrees C for nine hours. In addition to stress relief, carbide precipitation can also occur, and their relative contributions to the improvement is discussed

Flow Vaporization of CO{sub 2} in Microchannel Tubes

Energy Technology Data Exchange (ETDEWEB)

Pettersen, Jostein

2002-07-01

Carbon dioxide is receiving renewed interest as an efficient and environmentally safe refrigerant in a number of applications, including mobile air conditioning and heat pump systems, and hot water heat pumps. Compact heat exchangers for CO{sub 2} systems are designed with small-diameter tubing. The purpose of this study is therefore to provide a better basis for understanding and predicting heat transfer and pressure drop during flow vaporization of CO{sub 2} in microchannels. The ''unusual'' properties of carbon dioxide give heat transfer and two-phase flow characteristics that are very different from those of conventional refrigerants. Examples of these differences are the much higher pressure, the resulting high vapour density, a very low surface tension, and a low liquid viscosity. High pressure and low surface tension has a major effect on nucleate boiling characteristics, and earlier test data have shown a clear dominance of nucleate boiling even at very high mass flux. Heat transfer tests were conducted in a rig using a flat, extruded aluminium microchannel tube of 540 mm length with 25 channels of 0.81 mm diameter. The horizontal test tube was heated by a water jacket in order to get representative boundary conditions for air-to-refrigerant heat transfer (''fluid heating''). Constant heat flux conditions do not simulate these boundary conditions well, and may give unrealistic behaviour especially in relation to dryout and post-dryout heat transfer. Systematic tests at constant heat flux with single-phase CO{sub 2} flow on the inside generated data that were used in the derivation of a model for water-side beat transfer coefficient. A regression based on these data gave a calibrated equation for water-side heat transfer on the form NuNu(Re,Pr). This equation was then used in later experiments to subtract water-side thermal resistance from the measured overall resistance (1/UA), thereby finding the internal heat

RBF–ARX model of an industrial furnace for drying olive pomace

International Nuclear Information System (INIS)

Casanova-Peláez, P.J.; Cruz-Peragón, F.; Palomar-Carnicero, J.M.; Dorado, R.; López-García, R.

2012-01-01

Highlights: ► We model a real furnace, fuelled with orujo, used to dry olive pomace. ► We apply a radial basic functions–auto-regression with exogenous variables (ARXs–RBFs) method. ► Root-mean-square error and r 2 are used to validate the ARX–RBF model. - Abstract: Drying operations are common in food industries. One of the main components in a drying system is the furnace. The furnace operation involves heat–mass transfer and combustion, thus it demands a complex mathematic representation. Since autoregressive methods are simple, and help to simulate rapidly a system, we model a drying furnace of olive pomace via an auto-regression with exogenous variables (ARXs) method. A neural network of radial basic functions (RBFs) defines the ARX experimental relation between the amounts of dry pomace (moisture content of 15%) used like fuel and the temperature of outlet gases. A real industrial furnace is studied to validate the proposed model, which can help to control the drying process.

Developing and testing a vertical sintering furnace for remote nuclear applications

International Nuclear Information System (INIS)

Nesbitt, J.F.; Ryer, C.M.

1980-01-01

Horizontal-type furnaces used to sinter fuel pellets on a production basis are large and thus impractical for remote applications. However, research has shown that vertical-type furnaces are adaptable for use and are cheaper to operate and maintain. In 1979, Pacific Northwest Laboratory, working under the auspices of the Department of Energy's Fuel Refabrication and Development (FRAD) Program, began developing an advanced concept for a remotely operated furnace designed specifically to sinter nuclear fuel pellets. The FRAD Program at PNL ended before the sintering of nuclear fuels could be completely verified. However during 1979, PNL performed a sufficient number and variety of tests to establish that nuclear fuel pellets can be sintered in a vertical furnace

Integration of Tuyere, Raceway and Shaft Models for Predicting Blast Furnace Process

Science.gov (United States)

Fu, Dong; Tang, Guangwu; Zhao, Yongfu; D'Alessio, John; Zhou, Chenn Q.

2018-06-01

A novel modeling strategy is presented for simulating the blast furnace iron making process. Such physical and chemical phenomena are taking place across a wide range of length and time scales, and three models are developed to simulate different regions of the blast furnace, i.e., the tuyere model, the raceway model and the shaft model. This paper focuses on the integration of the three models to predict the entire blast furnace process. Mapping output and input between models and an iterative scheme are developed to establish communications between models. The effects of tuyere operation and burden distribution on blast furnace fuel efficiency are investigated numerically. The integration of different models provides a way to realistically simulate the blast furnace by improving the modeling resolution on local phenomena and minimizing the model assumptions.

Minimization of Blast furnace Fuel Rate by Optimizing Burden and Gas Distribution

Energy Technology Data Exchange (ETDEWEB)

Dr. Chenn Zhou

2012-08-15

The goal of the research is to improve the competitive edge of steel mills by using the advanced CFD technology to optimize the gas and burden distributions inside a blast furnace for achieving the best gas utilization. A state-of-the-art 3-D CFD model has been developed for simulating the gas distribution inside a blast furnace at given burden conditions, burden distribution and blast parameters. The comprehensive 3-D CFD model has been validated by plant measurement data from an actual blast furnace. Validation of the sub-models is also achieved. The user friendly software package named Blast Furnace Shaft Simulator (BFSS) has been developed to simulate the blast furnace shaft process. The research has significant benefits to the steel industry with high productivity, low energy consumption, and improved environment.

Process and furnace for working bituminous materials

Energy Technology Data Exchange (ETDEWEB)

Klotzer, M

1921-06-28

A process for working up bitumen-containing materials, such as coal, peat and shale is characterized in that the material in thin-height batches with constant shaking by means of forward and backward movement of an elongated horizontal hearth heated underneath on which the material freely lies and on which it is moved in the furnace, through a single narrow furnace space with zone-wise heating of the hearth. A drying zone, a spent-material removal zone, and a carbonization zone are provided. Under separate hoods the gases and vapors are removed from these zones.

Measure Guideline: High Efficiency Natural Gas Furnaces

Energy Technology Data Exchange (ETDEWEB)

Brand, L.; Rose, W.

2012-10-01

This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

A review of NOx formation mechanisms in recovery furnaces

International Nuclear Information System (INIS)

Nichols, K.M.; Thompson, L.M.; Empie, H.J.

1993-01-01

Review of NOx formation studies shows that NO forms in recovery furnaces primarily by two independent mechanisms, thermal and fuel. Thermal NO formation is extremely temperature-sensitive. However, theoretical predictions indicate that recovery furnace temperatures are not high enough to form significant thermal NO. Fuel NO formation is less temperature-sensitive, and is related to fuel nitrogen content. Black liquors are shown to contain 0.05 to 0.24 weight percent fuel nitrogen. Conversion of just 20% of this would yield approximately 25-120 ppm NOx (at 8% 0 2 ) in the flue gas, enough to represent the majority of the total NOx. Data from operating recovery furnaces show NOx emissions ranging from near zero to over 100 ppm at 8% 0 2 . An apparent increase in recovery furnace NOx emissions was observed with increasing solids. This increase is much less than predicted by thermal NO formation theory, indicating that other NO formation/destruction mechanisms, such as fuel NO formation, are important. No data are available to show the relative importance of thermal and fuel NO to total NOx during black liquor combustion

Comparison of a burning mass ceramics coating in laboratory furnace and instrustrial furnace; Comparacao de queimas de uma massa ceramica de revestimento em forno de laboratorio e forno industrial

Energy Technology Data Exchange (ETDEWEB)

Soares, R.A.L., E-mail: robertoarruda@ifpi.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Piaui (IFPI), Terersina, PI (Brazil); Castro, J.R. de S. [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil)

2012-07-01

This work intends to analyze the differences obtained in the technological properties of a ceramic coating after firing in two distinct environments, laboratory furnace and industrial furnace. For this, was characterized a ceramic mass used in the production of porous coating. The analyzes were performed chemical, mineralogical and thermal mass in that. The specimens were obtained by compacting and burned in the maximum temperature of 1140 deg C in two furnaces, laboratory and industrial. The technological tests were performed linear shrinkage, water absorption, bulk density and mechanical strength. The microstructure was evaluated by ray-X diffraction and scanning electron microscopy. The results showed that both furnaces provided significant differences in analyzed specimens, such as increased strength and low water absorption in the fired samples in a laboratory furnace, for example. (author)

Numerical analysis of the influence of circuit arrangement on a fin-and-tube condenser performance

Directory of Open Access Journals (Sweden)

Cesare Maria Joppolo

2015-09-01

Full Text Available In the present paper a model for the steady-state simulation of fin-and-tube condenser is developed. The model is based on a finite volume approach that divides each tube into small elemental volumes where mass, momentum and energy conservation equations are solved using the effectiveness-NTU method and with appropriate correlations for void fraction, friction factor and heat transfer coefficient calculation. The model is validated against experimental data on two small condensers finding that the calculated heat transfer rate and refrigerant-side pressure drop agree within ±5% and ±21% respectively to the experimental values. The model is then used to numerically analyse the impact of different circuit arrangements on the condenser heat transfer rate, refrigerant-side pressure drop and refrigerant charge.

Numerical modelling of an industrial glass-melting furnace

Energy Technology Data Exchange (ETDEWEB)

Hill, S C [Brigham Young Univ., Advanced Combustion Engineering Research Center, Provo, UT (United States); Webb, B W; McQuay, M Q [Brigham Young Univ., Mechanical Engineering Dept., Provo, UT (United States); Newbold, J [Lockheed Aerospace, Denver, CO (United States)

2000-03-01

The predictive capability of two comprehensive combustion codes, PCGC-3 and FLUENT, to simulate local flame structure and combustion characteristics in a industrial gas-fired, flat-glass furnace is investigated. Model predictions are compared with experimental data from the furnace for profiles of velocity, species concentrations, temperatures, and wall-incident radiative heat flux. Predictions from both codes show agreement with the measured mean velocity profiles and incident radiant flux on the crown. However, significant differences between the code predictions and measurements are observed for the flame-ozone temperatures and species concentrations. The observed discrepancies may be explained by (i) uncertainties in the distributions of mean velocity and turbulence in the portneck, (ii) uncertainties in the port-by-port stoichiometry, (iii) different grid-based approximations to the furnace geometry made in the two codes, (iv) the assumption of infinitely fast chemistry made in the chemical reaction model of both codes, and (v) simplifying assumptions made in the simulations regarding the complex coupling between the combustion space, batch blanket, and melt tank. The study illustrates the critical need for accurate boundary conditions (inlet air and fuel flow distributions, boundary surface temperatures, etc.) and the importance of representative furnace geometry in simulating these complex industrial combustion systems. (Author)

Steam generators and furnaces

Energy Technology Data Exchange (ETDEWEB)

Swoboda, E

1978-04-01

The documents published in 1977 in the field of steam generators for conventional thermal power plants are classified according to the following subjects: power industry and number of power plants, planning and operation, design and construction, furnaces, environmental effects, dirt accumulation and corrosion, conservation and scouring, control and automation, fundamental research, and materials.

DEVELOPMENT AND TESTING OF COMPOUND FUEL CHAMBER WITHOUT A GRATE FOR HOUSEHOLD FURNACE

Directory of Open Access Journals (Sweden)

Shevyakov Vladimir Viktorovich

2018-02-01

Full Text Available In hearth furnaces, the firewood is burned more cleanly with less carbon monoxide at the outlet. The disadvantage of such fireboxes is a longer process of coal burnout than in grate-fired furnaces. In furnaces with a grate, the burnout time of coals is less, which makes it possible to finish the combustion process more quickly and close the outlet latch. This increases the efficiency of the furnace but to further reduce the time of burning out the coals they have to be raked and burned on the grate. This complicates the process of operating the furnace itself. The proposed design of the compound firebox allows us to improve characteristics of both the firebox itself and the entire furnace. Research objectives: creation and study of a compound firebox that increases the efficiency of the furnace and simplifies the furnace maintenance process with the values of carbon monoxide at the outlet comparable to hearth furnaces. Materials and methods: a detailed analysis of hearth fuel chambers ECO+ was carried out according to the amount of carbon monoxide at the outlet. The results of the analysis are used for comparison with compound fuel chamber. The structure of the compound firebox was chosen based on the results of preliminary tests of several fuel chambers proposed and tested by the author in the furnace PDKSh-2.0. A peculiarity of the structure of the compound firebox is the absence of a grate and the presence of a narrow slit in the lower part of the firebox through which the incoming air enters the firewood. Between the walls of the firebox and firewood, skids are installed, forming an air gap, through which the inlet air is uniformly supplied to the entire firewood supply. With gradual combustion of firewood and formation of coal, the firewood descends to the bottom of the firebox, where they intensively burn out in the maximum air flow. Compound firebox consists of several parts, it is made of steel with a thickness of 4.0 mm and installed

Design and Construction of Oil Fired Compact Crucible Furnace ...

African Journals Online (AJOL)

As a prelude to necessary industrialization, foundries are springing up in various parts of Nigeria and most of these foundries rely on oil fired furnaces in their operation. This study is aimed at developing an oil fired crucible furnace from locally sourced materials for foundries in Nigeria. In our design, a new system of fuel ...

CHARCOAL PACKED FURNACE FOR LOW-TECH CHARRING OF BONE

DEFF Research Database (Denmark)

Jacobsen, P.; Dahi, Elian

1997-01-01

A low-tech furnace for charring of raw bone using char coal is developed and tested. The furnace consists of a standard oil drum, fitted with simple materials as available in every market in small towns in developing counties. 80 kg of raw bone and 6 kg of charcoal are used for production of 50 kg...

Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Bentlin, Fabrina R.S. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil); Pozebon, Dirce [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil)], E-mail: dircepoz@iq.ufrgs.br; Mello, Paola A.; Flores, Erico M.M. [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900 Santa Maria, RS (Brazil)

2007-10-17

A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO{sub 3}){sub 2} was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 {mu}g g{sup -1} of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

Special analyses reveal coke-deposit structure

International Nuclear Information System (INIS)

Albright, L.F.

1988-01-01

A scanning electron microscope (SEM) and an energy dispersive X-ray analyzer (EDAX) have been used to obtain information that clarifies the three mechanisms of coke formation in ethylene furnaces, and to analyze the metal condition at the exit of furnace. The results can be used to examine furnace operations and develop improved ethylene plant practices. In this first of four articles on the analyses of coke and metal samples, the coking mechanisms and coke deposits in a section of tube from an actual ethylene furnace (Furnace A) from a plant on the Texas Gulf Coast are discussed. The second articles in the series will analyze the condition of the tube metal in the same furnace. To show how coke deposition and metal condition dependent on the operating parameters of an ethylene furnace, the third article in the series will show the coke deposition in a Texas Gulf Coast furnace tube (Furnace B) that operated at shorter residence time. The fourth article discusses the metal condition in that furnace. Some recommendations, based on the analyses and findings, are offered in the fourth article that could help extend the life of ethylene furnace tubes, and also improve overall ethylene plant operations

Flow pattern assessment in tubes with wire coil inserts in laminar and transition regimes

International Nuclear Information System (INIS)

Garcia, A.; Solano, J.P.; Vicente, P.G.; Viedma, A.

2007-01-01

The paper presents an analysis of the flow mechanisms in tubes with wire coils using hydrogen bubble visualization and PIV techniques. Results have been contrasted with experimental data on pressure drop. The relation between the observed flow patterns and the friction factor has been analysed. The experimental analysis that has been carried out allows one to state that at low Reynolds numbers (Re < 400) the flow in tubes with wire coils is basically similar to the flow in smooth tubes. At Reynolds numbers between 500 and 700 and in short pitch wire coils a recirculating flow appears. The insertion of wires coils in a smooth tube accelerates significantly the transition to turbulence. This is produced at Reynolds numbers between 700 and 1000 depending on the wire pitch

Behaviour of radionuclides during accidental melting of orphan sources in electric arc furnaces by means of C.F.D. gas flow modeling

International Nuclear Information System (INIS)

Penalva, I.; Damborenea, J.; Legarda, F.; Zuloaga, P.; Ordonez, M.; Serrano, I.

2006-01-01

The appearance of orphan sources in steelmaking facilities has become a fact nowadays. Radiation sources, hidden within the scrap, may come into the scrap yard and become part of the melting. As a result, dispersion of the radioactive material that makes up the source takes place throughout the facility. The University of the Basque Country (U.P.V.-E.H.U.), in collaboration with the Empresa Nacional de Residuos Radiactivos, S.A. (E.N.R.E.S.A.) and the Consejo de Seguridad Nuclear (C.S.N.), has carried out a Research Project to analyze this accidental melting of radioactive sources in electric arc furnaces (E.A.F.). The whole steelmaking process can be analyzed in several discrete phases. Radioactive sources that may be incorporated to this process will be exposed to the different critical conditions prevailing during each phase. In this sense, Computational Fluid Dynamics (C.F.D.) has been used in order to recreate such conditions and so, determine the characteristics of the dispersion of radioactivity. Two different situations have been studied in detail using C.F.D. techniques: thermal conditions around a scrap-basket that contains the source just before entering the furnace and the deposition of steelmaking dust containing 137 Cs on the inner surface of flue pipes. Before entering the furnace, scrap is usually placed inside a basket that remains above the furnace during some time. Once the furnace is open the scrap is dropped into the furnace to complete the loading process. C.F.D. techniques have been used to analyze the thermal conditions around the basket in order to assess the possibility of a break of the radioactive source hidden within the scrap, concluding that commercial sources will maintain their integrity during the whole loading process. On the other hand, after entering the furnace dispersion of the radioactive material will take place. Physical and chemical properties of the active elements (chemical form, composition, melting point, etc

Behaviour of radionuclides during accidental melting of orphan sources in electric arc furnaces by means of C.F.D. gas flow modeling

Energy Technology Data Exchange (ETDEWEB)

Penalva, I.; Damborenea, J.; Legarda, F. [University of the Basque Country, Nuclear Engineering and Fluids Mechanics (Spain); Zuloaga, P.; Ordonez, M. [Empresa Nacional de Residuos Radiactivos, SA (ENRESA), Madrid (Spain); Serrano, I. [Consejo de Seguridad Nuclear, Madrid (Spain)

2006-07-01

The appearance of orphan sources in steelmaking facilities has become a fact nowadays. Radiation sources, hidden within the scrap, may come into the scrap yard and become part of the melting. As a result, dispersion of the radioactive material that makes up the source takes place throughout the facility. The University of the Basque Country (U.P.V.-E.H.U.), in collaboration with the Empresa Nacional de Residuos Radiactivos, S.A. (E.N.R.E.S.A.) and the Consejo de Seguridad Nuclear (C.S.N.), has carried out a Research Project to analyze this accidental melting of radioactive sources in electric arc furnaces (E.A.F.). The whole steelmaking process can be analyzed in several discrete phases. Radioactive sources that may be incorporated to this process will be exposed to the different critical conditions prevailing during each phase. In this sense, Computational Fluid Dynamics (C.F.D.) has been used in order to recreate such conditions and so, determine the characteristics of the dispersion of radioactivity. Two different situations have been studied in detail using C.F.D. techniques: thermal conditions around a scrap-basket that contains the source just before entering the furnace and the deposition of steelmaking dust containing {sup 137}Cs on the inner surface of flue pipes. Before entering the furnace, scrap is usually placed inside a basket that remains above the furnace during some time. Once the furnace is open the scrap is dropped into the furnace to complete the loading process. C.F.D. techniques have been used to analyze the thermal conditions around the basket in order to assess the possibility of a break of the radioactive source hidden within the scrap, concluding that commercial sources will maintain their integrity during the whole loading process. On the other hand, after entering the furnace dispersion of the radioactive material will take place. Physical and chemical properties of the active elements (chemical form, composition, melting point, etc

Radiation from Large Gas Volumes and Heat Exchange in Steam Boiler Furnaces

Energy Technology Data Exchange (ETDEWEB)

Makarov, A. N., E-mail: tgtu-kafedra-ese@mail.ru [Tver State Technical University (Russian Federation)

2015-09-15

Radiation from large cylindrical gas volumes is studied as a means of simulating the flare in steam boiler furnaces. Calculations of heat exchange in a furnace by the zonal method and by simulation of the flare with cylindrical gas volumes are described. The latter method is more accurate and yields more reliable information on heat transfer processes taking place in furnaces.

The technological raw material heating furnaces operation efficiency improving issue

Science.gov (United States)

Paramonov, A. M.

2017-08-01

The issue of fuel oil applying efficiency improving in the technological raw material heating furnaces by means of its combustion intensification is considered in the paper. The technical and economic optimization problem of the fuel oil heating before combustion is solved. The fuel oil heating optimal temperature defining method and algorithm analytically considering the correlation of thermal, operating parameters and discounted costs for the heating furnace were developed. The obtained optimization functionality provides the heating furnace appropriate thermal indices achievement at minimum discounted costs. The carried out research results prove the expediency of the proposed solutions using.

A Heat and Mass Transfer Model of a Silicon Pilot Furnace

Science.gov (United States)

Sloman, Benjamin M.; Please, Colin P.; Van Gorder, Robert A.; Valderhaug, Aasgeir M.; Birkeland, Rolf G.; Wegge, Harald

2017-10-01

The most common technological route for metallurgical silicon production is to feed quartz and a carbon source ( e.g., coal, coke, or charcoal) into submerged-arc furnaces, which use electrodes as electrical conductors. We develop a mathematical model of a silicon furnace. A continuum approach is taken, and we derive from first principles the equations governing the time evolution of chemical concentrations, gas partial pressures, velocity, and temperature within a one-dimensional vertical section of a furnace. Numerical simulations are obtained for this model and are shown to compare favorably with experimental results obtained using silicon pilot furnaces. A rising interface is shown to exist at the base of the charge, with motion caused by the heating of the pilot furnace. We find that more reactive carbon reduces the silicon monoxide losses, while reducing the carbon content in the raw material mixture causes greater solid and liquid material to build-up in the charge region, indicative of crust formation (which can be detrimental to the silicon production process). We also comment on how the various findings could be relevant for industrial operations.

Experimental Study on Environment Friendly Tap Hole Clay for Blast Furnace

Science.gov (United States)

Siva kumar, R.; Mohammed, Raffi; Srinivasa Rao, K.

2018-03-01

Blast furnace (BF) is the best possible route of iron production available. Blast furnace is a high pressure vessel where iron ore is melted and liquid iron is produced. The liquid iron is tapped through the hole in Blast Furnace called tap hole. The tapped liquid metal flowing through the tap hole is plugged using a clay called tap hole clay. Tap hole clay (THC) is a unshaped refractory used to plug the tap hole. The tap hole clay extruded through the tap hole using a gun. The tap hole clay is designed to expand and plug the tap hole. The tap hole filled with clay is drilled using drill bit and the hole made through the tap hole to tap the liquid metal accumulated inside the furnace. The number of plugging and drilling varies depending on the volume of the furnace. The tap hole clay need to have certain properties to avoid problems during plugging and drilling. In the present paper tap hole clay properties in industrial use was tested and studied. The problems were identified related to tap hole clay manufacturing. Experiments were conducted in lab scale to solve the identified problems. The present composition was modified with experimental results. The properties of the modified tap hole clay were found suitable and useful for blast furnace operation with lab scale experimental results.

Design of safety monitor system for operation sintering furnace ME-06

International Nuclear Information System (INIS)

Sugeng Rianto; Triarjo; Djoko Kisworo; Agus Sartono

2013-01-01

Design of safety monitoring system for safety operation of sinter furnace ME-06 has been done. Parameters monitored during this operation include: temperature, gas pressure, flow rate of gas, voltage and current furnace. For sintering furnace temperature system that monitored were the temperature of the furnace temperature, the temperature of the cooling water system inlet and outlet, temperature of flow hydrogen gas inlet and outlet. For pressure system and flow rate gas sinter furnace which monitored the pressure and flow rate of hydrogen gas inlet and outlet. The system also monitors current and voltage applied to the sinter furnace heating system. Monitor system hardware consists of: the system temperature sensor, pressure, rate and data acquisition systems. While software systems using the labview driver interface that connects the hard and software systems. Function test results during sintering operation for setting the temperature 1700 °C sintering temperature increases the ramp function by 250 °C/hour average measurements obtained when the sintering time 1707.016 °C with a standard deviation of 0.38 °C. The maximum temperature of the hydrogen gas temperature 35.4 °C. The maximum temperature of the cooling water system 27.4 °C. The maximum pressure of 1,911 bar Gas Inlet and outlet of 0,051 bar. Maximum inlet gas flow 12.996 L / min and outlet 14.086 L / min. (author)

Mathematical Determination of Thermal Load for Fluidised Bed Furnaces Using Sawdust

Directory of Open Access Journals (Sweden)

Antonescu Nicolae

2014-06-01

Full Text Available For technical applications, a physical model capable of predicting the particle evolution in the burning process along its trajectory through the furnace is very useful. There are two major demands: all the thermo-dynamic processes that describe the particle burning process must be accounted and the model must be written in such equation terms to allow the intervention for parameter settings and particle definition. The computations were performed for the following parameters: furnace average temperature between 700 and 1200 °C, size of the sawdust particle from 4 to 6 mm and fix carbon ignition between 500 and 900 °C. The values obtained for the characteristic parameters of the burning process ranged from 30 to 60 [kg/(h·m3] for the gravimetrical burning speed WGh and from 150 to 280 [kW/m3] for the volumetric thermal load of the furnace QV. The main conclusion was that the calculus results are in good agreement with the experimental data from the pilot installations and the real-case measurements in the sawdust working boiler furnaces or pre-burning chambers. Another very important conclusion is that the process speed variation, when the furnace temperature changes, confirms the thermo-kinetic predictions, namely that the burning process speed decreases when the furnace temperature increases.

Liquid flow in the hearth of the blast furnace

International Nuclear Information System (INIS)

Gauje, P.; Nicolle, R.; Steiler, J.M.; Venturini, M.J.; Libralesso, J.M.

1992-01-01

The hearth of a blast furnace is poorly known. Our approach to characterize the hearth involves classical methods of chemical engineering, assessing the flow conditions by means of radioactive tracer techniques. The most important feature of this study is to combine measurements on industrial blast furnaces, experiments on a small scale model and flow model. calculations. 8 refs., 16 figs

Granulated blast furnace slag – A boon for foundry industry

African Journals Online (AJOL)

Keywords: Silica sand; Blast Furnace Slag; Mould properties; Ferrous and nonferrous ... raw material for the production of cast components in foundry industries. ... applications for conserving natural resources and reduce the cost of the raw .... in an elevated temperature melting furnace with temperature values of 750 to.

Modeling of glass fusion furnaces; Modelisation des fours de fusion de verre

Energy Technology Data Exchange (ETDEWEB)

Mechitoua, N. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches; Plard, C. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

1997-12-31

The furnaces used for glass melting are industrial installations inside which complex and coupled physical and chemical phenomena occur. Thermal engineering plays a major role and numerical simulation is a precious tool for the analysis of the different coupling, of their interaction and of the influence of the different parameters. In order to optimize the functioning of glass furnaces and to improve the quality of the glass produced, Electricite de France (EdF) has developed a specialized version of the ESTET fluid mechanics code, called `Joule`. This paper describes the functioning principle of glass furnaces, the interactions between heat transfers and flows inside the melted glass, the interactions between heat transfers and the thermal regulation of the furnace, the interactions between heat transfers and glass quality and the heat transfer interactions between the melted glass, the furnace walls and the combustion area. (J.S.)

X-ray diffractometry of steam cured ordinary Portland and blast-furnace-slag cements

International Nuclear Information System (INIS)

Camarini, G.; Djanikian, J.G.

1994-01-01

This work studies some aspects of the phases produced by hydration of ordinary and blast-furnace-slag cements, at normal conditions and steam cured (60 and 95 0 C), using an X-ray diffraction technique. The blast-furnace-slag cement was a mixture of 50% of ordinary Portland cement and 50% of blast-furnace-slag (separately grinding). After curing the X-ray diffraction reveals that, in relation to ordinary Portland cement, the main phases in blast-furnace-slag cement are hydrated silicates and aluminates, hydro garnet, etringitte and mono sulphate. After steam curing the hydration of blast-furnace-slag cement proceeds. This is a result of the slag activation by the curing temperature. (author). 8 refs., 3 figs., 1 tab

Development of the high temperature sintering furnace for DUPIC fuel fabrication

International Nuclear Information System (INIS)

Lee, Jung Won; Kim, B. G.; Park, J. J.; Yang, M. S.; Kim, K. H.; Kim, J. H.; Cho, K. H.; Lee, D. Y.; Lee, Y. S.

1998-11-01

This report describes the development of the high temperature sintering furnace for manufacturing DUPIC (Direct Use of spent PWR fuel in CANDU reactors) fuel pellets. The furnace has to be remotely operated and maintained in a high radioactive hot cell using master-slave manipulators. The high temperature sintering furnace for manufacturing DUPIC fuel pellets, which is satisfied with the requirements of remote operation and maintenance in a hot cell, was successfully developed and installed in the M6 hot cell at IMEF (Irradiated Material Examination Facility). The functional and thermal performance test was also successfully completed. The technology accumulated during developing this sintering furnace became the basis of other DUPIC equipment development, and will be very helpful in the development of equipment for use in hot cell in the future. (author). 20 figs

Combustion of drops of Mexican fuel oils with high asphaltenes content; Combustion de gotas de combustoleos mexicanos con alto contenido de asfaltenos

Energy Technology Data Exchange (ETDEWEB)

Garcia Rodriguez, Jose Francisco [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-09-01

In this work the combustion of fuel drops with a content of 18% of asphaltenes has been studied . The results obtained for this fuel were compared with the ones obtained for another with a content of 12% asphaltenes. The drops were suspended in a platinum filament and burned in an spherical radiant furnace. The drop size varied between 600 and 800 microns. The fuel drops with 12% asphaltenes showed shorter combustion times, a smaller diameter increment of the smaller diameter during the combustion stages and also a shorter burning time of the carbonaceous residue than the fuel drops with a content of 18% asphaltenes. [Espanol] En el presente trabajo se ha estudiado la combustion de gotas de combustible con 18% de contenido de asfaltenos. Los resultados obtenidos para este combustible se compararon con los obtenidos para otro con 12% de contenido de asfaltenos. Las gotas fueron suspendidas en un filamento de platino y quemadas en un horno radiante esferico. El tamano de las gotas vario entre 600 y 800 micras. Las gotas de combustible con 12% de asfaltenos mostraron tiempos de combustion mas cortos, un incremento del diametro menor durante las etapas de combustion y un tiempo de quemado del residuo carbonoso tambien mas corto que las gotas del combustible con 18% de contenido de asfaltenos.

High temperature corrosion in a biomass-fired power boiler : Reducing furnace wall corrosion in a waste wood-fired power plant with advanced steam data

OpenAIRE

Alipour, Yousef

2013-01-01

The use of waste (or recycled) wood as a fuel in heat and power stations is becoming more widespread in Sweden (and Europe), because it is CO2 neutral with a lower cost than forest fuel. However, it is a heterogeneous fuel with a high amount of chlorine, alkali and heavy metals which causes more corrosion than fossil fuels or forest fuel. A part of the boiler which is subjected to a high corrosion risk is the furnace wall (or waterwall) which is formed of tubes welded together. Waterwalls are...

Drop Impact Dynamics with Sessile Drops and Geometries: Spreading, Jetting, and Fragmentation

Science.gov (United States)

Tilger, Christopher F.

The tendency of surface tension to cause small parcels of fluid to form into drops allows convenient packaging, transport, dispersal of liquid phase matter. Liquid drop impacts with solids, liquids, and other drops have realized and additional future applications in biological, manufacturing, heat transfer, and combustion systems. Experiments were conducted to investigate the dynamics of multiple drop collisions, rather than the most-studied phenomenon of single drop impacts. Additional drop impacts were performed on rigid hemispheres representing sessile drops, angled substrates, and into the vertex of two tilted surfaces arranged into a vee shape. A qualitative inspection of drop-sessile drop impacts shows distinct post-impact shapes depending on the offset distance between the drops. At intermediate offset distances, distinct jets issue from the overlap region between the two drops projected areas. These jets are observed to reach their maximum extent at a critical offset distance ratio, epsilon epsilon ˜ 0.75-0.80, with substrate contact angle and W e having a lesser effect. Capillary waves that traverse the sessile drop after collision cause a lower aspect ratio liquid column to emanate from the sessile drop opposite the impact. In order to better understand the jetting phenomenon seen in the offset drop-sessile drop impacts, simpler solid geometries are investigated that elicit a similar behavior. Solid hemispheres do not show the singular jetting observed in the fluidic case, however, a simple vee formed by two intersection planar substrates do jet in a similar fashion to the fluidic case. A geometric model with partnered experiments is developed to describe the bisymmetric spread of an impacting drop on an angled substrate. This geometric model is used to guide a time of arrival based model for various features of the drop impact, which is used to predict jetting in various vee channel experiments.

Analysis of combustion efficiency in a pelletizing furnace

Directory of Open Access Journals (Sweden)

Rafael Simões Vieira de Moura

Full Text Available Abstract The objective of this research is to assess how much the improvement in the combustion reaction efficiency can reduce fuel consumption, maintaining the same thermal energy rate provided by the reaction in a pelletizing furnace. The furnace for pelletizing iron ore is a complex thermal machine, in terms of energy balance. It contains recirculation fan gases and constant variations in the process, and the variation of a single process variable can influence numerous changes in operating conditions. This study demonstrated how the main variables related to combustion in the burning zone influence fuel consumption (natural gas from the furnace of the Usina de Pelotização de Fábrica (owned by VALE S/A, without changing process conditions that affect production quality. Variables were analyzed regarding the velocity and pressure of the fuel in the burners, the temperature of the combustion air and reactant gases, the conversion rate and the stoichiometric air/fuel ratio of the reaction. For the analysis, actual data of the furnace in operation was used, and for the simulation of chemical reactions, the software Gaseq® was used. The study showed that the adjustment of combustion reaction stoichiometry provides a reduction of 9.25% in fuel consumption, representing a savings of US$ 2.6 million per year for the company.

Analysis of rod drop and pulsed source measurements of reactivity in the Winfrith SGHWR

International Nuclear Information System (INIS)

Brittain, I.

1970-05-01

Reactivity measurements by the rod-drop and pulsed source methods in the Winfrith SGHWR are seriously affected by spatial harmonics. A method of calculation is described which enables the spatial harmonics to be calculated in non-uniform cores in two or three dimensions, and thus allows a much more rigorous analysis of the experimental results than the usual point model. The method is used to analyse all the rod-drop measurements made during commissioning of the Winfrith SGHWR, and to comment on the results of pulsed source measurements. The reactivity worths of banks of ten and twelve shut-down tubes deduced from rod-drop and pulsed source experiments are in satisfactory agreement with each other and also with AIMAZ calculated values. The ability to calculate higher spatial harmonics in nonuniform cores is thought to be new, and may have a wider application to reactor kinetics through the method of Modal Analysis. (author)

Nonmetallic inclusions in carbon steel smelted in plasma furnace

Energy Technology Data Exchange (ETDEWEB)

Shengelaya, I B; Kostyakov, V N; Nodiy, T K; Imerlishvili, V G; Gavisiani, A G [AN Gruzinskoj SSR, Tbilisi. Inst. Metallurgii

1979-01-01

A complex investigation on nonmetallic inclusions in carbon cast iron, smelted in plasma furnace in argon atmosphere and cast partly in the air and partly in argon atmosphere, has been carried out. As compared to open-hearth furnace carbon steel, the test metal was found to contain more oxide inclusions and nitrides; besides, in chromium-containing metal, chromium nitrides form the larger part of nitrides.

Investigation and analysis of the usefulness of the Zellik method to design energy conserving electric furnaces

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, L.; Fay, G.

1984-01-01

The characteristics predetermined by the method Zellik in designing the electrical furnaces isolated traditionally are comparable with measured values of furnaces in operation. The newest furnaces have been built with isolation resulting in a lower energy consumption. To plot the static characteristics, the furnace was heated up three times to the steady state. In determining the static heat capacity the stored heat was measured by the conventional method. With a view to determining the kinetic heat capacity the furnace was heated up at different rates. On the base of the operating results of the furnace can be stated both the practicability of the method Zellik and the improvement of the characteristics of the furnace isolated with fibrous material.

Method of burning highly reactive strongly slagging coal dust in a chamber furnace

Energy Technology Data Exchange (ETDEWEB)

Protsaylo, M.Ya.; Kotler, V.R.; Lobov, G.V.; Mechev, V.P.; Proshkin, A.V.; Zhuravlev, Yu.A.

1982-01-01

In the chamber furnace in order to reduce slagging, it is proprosed that, above the coal dust burners, nozzles be installed with inclination downwards through which air is fed in a mixture with flue gases. Under the influence of this flue gas-air mixture, the coal dust flame is deviated downwards. In this case there is an increase in the length of the flame and degree of filling of the volume of the furnace with the flame. This increases the effectiveness of dust burning. The input into the furnace of fuel jointly with the air and flue gases (optimally 10-15% of the total quantity of gases formed during fuel combustion) makes it possible to reduce the temperature in the furnace and the probability of slagging of the furnace walls.

Steady finite-Reynolds-number flows in three-dimensional collapsible tubes

Science.gov (United States)

Hazel, Andrew L.; Heil, Matthias

2003-07-01

A fully coupled finite-element method is used to investigate the steady flow of a viscous fluid through a thin-walled elastic tube mounted between two rigid tubes. The steady three-dimensional Navier Stokes equations are solved simultaneously with the equations of geometrically nonlinear Kirchhoff Love shell theory. If the transmural (internal minus external) pressure acting on the tube is sufficiently negative then the tube buckles non-axisymmetrically and the subsequent large deformations lead to a strong interaction between the fluid and solid mechanics. The main effect of fluid inertia on the macroscopic behaviour of the system is due to the Bernoulli effect, which induces an additional local pressure drop when the tube buckles and its cross-sectional area is reduced. Thus, the tube collapses more strongly than it would in the absence of fluid inertia. Typical tube shapes and flow fields are presented. In strongly collapsed tubes, at finite values of the Reynolds number, two ’jets‘ develop downstream of the region of strongest collapse and persist for considerable axial distances. For sufficiently high values of the Reynolds number, these jets impact upon the sidewalls and spread azimuthally. The consequent azimuthal transport of momentum dramatically changes the axial velocity profiles, which become approximately uTheta-shaped when the flow enters the rigid downstream pipe. Further convection of momentum causes the development of a ring-shaped velocity profile before the ultimate return to a parabolic profile far downstream.

EFFECTS OF BLAST-FURNACE SLAG ON NATURAL POZZOLAN-BASED GEOPOLYMER CEMENT

Directory of Open Access Journals (Sweden)

MAHSHAD YAZDANIPOUR

2011-03-01

Full Text Available A number of geopolymer cement mixes were designed and produced by alkali-activation of a pumice-type natural pozzolan. Effects of blast-furnace slag on basic engineering properties of the mixes were studied. Different engineering properties of the mixes such as setting times and 28-day compressive strength were studied at different amounts of blast-furnace slag, sodium oxide content, and water-to-cement ratio. The mix comprising of 5 wt.% blast-furnace slag and 8 wt.% Na2O with a water-to-dry binder ratio of 0.30 exhibits the highest 28-day compressive strength, i.e. 36 MPa. Mixes containing 5 wt.% of ground granulated blast furnace slag showed the least efflorescence or best soundness. Laboratory techniques of X-ray diffractometry (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM were utilized for characterizing a number of mixes and studying their molecular and micro-structure. Investigations done by scanning electron microscopy confirm that smaller blast-furnace slag particles react totally while the larger ones react partially with alkaline activators and contribute to the formation of a composite microstructure.

Furnaces for destructive distillation

Energy Technology Data Exchange (ETDEWEB)

Gordon, A

1897-12-04

Shale or other material is dropped from a hopper F into an annular retort or kiln A/sup 3/, the walls of which enclose annular flues C, C/sup 1/ in which gas is burnt to heat it. Radial flues also extend across the kiln. The kiln is supported above the ground level by pillars B. The material rests at the bottom on an annular plate H, having a flat middle portion with inclined sides. This is supported within an annular hopper I, provided with counterweighted discharging doors I/sup 1/, held by latches and sealed by placing water on them; or a large conical hopper may be used, provided with a conveyer screw, and containing water. Four long scrapers J are reciprocated radially on the flat part of the plate H by rods J/sup 1/, passed through stuffing-boxes in the hopper, and engaged with eccentric K which are rotated by worm gearing. Doors M in the hopper I, and holes in the plate H, permit stirring-tools to be introduced. The upper part of the kiln consists of iron rings a, a/sup 1/; the products of combustion from the flues pass through openings a/sup 5/ into a central chimney a/sup 3/. The products of distillation are delivered through tubes G.

Creation of a contusion injury in rabbit skeletal muscle using a drop-mass technique

Directory of Open Access Journals (Sweden)

Margaret N. Deane

2013-08-01

Full Text Available This study reports our experience in developing a simple, minor injury. After reviewing the literature, a ‘drop-mass’ method was selected where a 201 g, elongated oval-shaped weight was dropped up to 15 times through a 1 m tube onto the left vastus lateralis of New Zealand white rabbits. To determine the extent of injury and degree of healing, biopsies were obtained six days after injury from the healing vastus lateralis of each animal. The tissue was fixed in formal saline, embedded in wax, cut and stained with haematoxylin and eosin (H&E and phosphotungstic acid haematoxylin (PTAH and examined by light microscopy (LM. The ‘optimal’ injury was created after seven drops, where quite severe, mild and moderately severe trauma was caused to muscle in the juxta-bone, mid and sub-dermal regions respectively. In each region, the muscle exhibited features of healing six days after injury. The ‘drop-mass’ technique appears to cause a contusion within a single muscle of at least three degrees of severity. This previously unreported observation is of particular importance to other researchers wishing to investigate contusion injury in other animal models.

Graphite electrode DC arc furnace system for treatment of environmentally undesirable solid waste

International Nuclear Information System (INIS)

Titus, C.H.

1993-01-01

A gas tight DC arc furnace system using graphite electrodes is ideally suited for destruction of organic materials, compaction of metallic materials, and vitrification of inorganic waste materials. A graphite electrode DC arc furnace system which was developed by Electro-Pyrolysis, Inc. has been used to demonstrate that iron basalt soil containing various surrogate nonradioactive materials found on Department of Energy's Atomic Energy Sites and hospital waste can be reduced to a compact, vitrified, solid material which is environmentally acceptable and will pass TCLP leachate tests. A second graphite electrode DC arc furnace system is presently under construction and will be in operation at MIT during the second quarter of 1993. This furnace system is designed for demonstration of waste treatment and stabilization at a rate of 500 pounds per hour and will also be used for development and performance evaluation of diagnostic techniques and equipment for measuring and understanding internal furnace temperature profiles, gas entrained particulate composition, and particulate size distribution in various locations in the furnace during operation

Modelling of carry-over in recovery furnaces

Energy Technology Data Exchange (ETDEWEB)

Fakhrai, Reza [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Metallurgy

2000-04-01

Development of mathematical modelling of the combustion process in the furnace of recovery boilers is the subject of this work. This work as a continuation of many years of modelling efforts carried out at KTH/Vaerme- och Ugnsteknik focussed particularly on: char bed modelling; droplets-wall interaction modelling; and carry-over modelling. The char bed model has been studied. Droplets/parcels were considered as a single reactor working independently of the other droplets. The mass of the droplets was not distributed uniformly but induced in the landing place. The droplets hitting the char bed will stick to it and they are alive and part of the calculation. In this way the distribution of the mass on the char bed is only dependent on the parameters which effect flight history such as droplet/parcel diameter, boilers flow field, etc. The droplet- wall interaction model has been studied and found to be very important for obtaining the correct temperature distribution in the recovery furnace. The new approach is based on removal of droplets which hits the wall in the upper part of the recovery boiler from carryover calculation. This model has been proposed and implemented into the GRFM (General Recovery Furnace Model). The carryover modelling effort was based on mass balance in which the number and physical statistics of the droplets/parcel were estimated and the amount of unburned mass was calculated. All of the above listed models were tested together with all other models of heat and mass transfer processes in recovery furnaces using a GRFM. Three-dimensional numerical simulations of the industrial recovery boiler (63 kg/s, 82 bar, 480 deg C) were performed. The number of grid was 232,000 and the number of air ports in this simulation was 178. The air entering the furnace by these ports has different flow rates. Flow and temperature fields as well as species distributions were calculated. The results show good agreement with previously published data and modelling

General correlations for pressure drop and heat transfer for single-phase turbulent flow in internally ribbed tubes

International Nuclear Information System (INIS)

Ravigururajan, T.S.; Bergles, A.E.

1985-01-01

General correlations for friction factors and heat transfer coefficients for single-phase turbulent flow in internally ribbed tubes are presented. Data from previous investigations are gathered for a wide range of tube parameters with e/d: 0.01 to 0.2; p/d: 0.1 to 7.0; α/90: 0.3 to 1.0, and flow parameters Re: 5000 to 250,000 and Pr: 0.66 to 37.6. The data were applied to a linear model to get normalized correlations that were then modified to fit tubes with extremely small parametric values. A shape function was included in the friction correlation to account for different rib profiles. The friction correlation predicts 96% of the data base to within +. 50% and 77% of the data base to within +. 20%. Corresponding figures for the heat transfer correlation are 99% and 69%. The present correlations are superior, for this extensive data base, to those presented by other investigators

Adjustment of pipe flow explicit friction factor equations for application to tube bundles

International Nuclear Information System (INIS)

Wiltz, Christopher L.; Bowen, Mike D.; Von Olnhausen, Wayne A.

2005-01-01

Full text of publication follows: The accurate determination of single phase friction losses or friction pressure drop in tube bundles is essential in the thermal-hydraulic analyses of components such as nuclear fuel assemblies, heat exchangers and steam generators. Such friction losses are normally calculated using a friction factor, f, along with the experimental observation that the friction pressure drop in a pipe is proportional to the dynamic pressure (1/2 ρV 2 ) of the flow: ΔP = 1/2 ρV 2 (fL/D). In this equation L is the pipe or tube bundle length and D is the hydraulic diameter of the pipe or tube bundle. The friction factor is normally calculated using one of a number of explicit friction factor equations. A significant amount of work has been accomplished in developing explicit friction factor equations. These explicit equations range from approximations, which were developed for ease of numerical evaluation, to those which are mathematically complex but yield very good fits to the test data. These explicit friction factor equations are based on a large experimental data base, nearly all of which comes from pipe flow geometry information, and have been historically applied to tube bundles. This paper presents an adjustment method which may be applied to various explicit friction factor equations developed for pipe flow to accurately predict the friction factor for tube bundles. The characteristic of the adjustment is based on experimental friction pressure loss data obtained by Framatome ANP through flow testing of a nuclear fuel assembly (tube bundle) at its Richland Test Facility (RTF). Through adjustment of previously developed explicit friction factor equations for pipe flow, the vast amount of historical development and experimentation in the area of single phase pipe flow friction loss may be incorporated into the evaluation of single phase friction losses within tube bundles. Comparisons of the application of one or more of the previously

Furnace Brazing Parameters Optimized by Taguchi Method and Corrosion Behavior of Tube-Fin System of Automotive Condensers

Science.gov (United States)

Guía-Tello, J. C.; Pech-Canul, M. A.; Trujillo-Vázquez, E.; Pech-Canul, M. I.

2017-08-01

Controlled atmosphere brazing has a widespread industrial use in the production of aluminum automotive heat exchangers. Good-quality joints between the components depend on the initial condition of materials as well as on the brazing process parameters. In this work, the Taguchi method was used to optimize the brazing parameters with respect to corrosion performance for tube-fin mini-assemblies of an automotive condenser. The experimental design consisted of five factors (micro-channel tube type, flux type, peak temperature, heating rate and dwell time), with two levels each. The corrosion behavior in acidified seawater solution pH 2.8 was evaluated through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. Scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDS) were used to analyze the microstructural features in the joint zone. The results showed that the parameters that most significantly affect the corrosion rate are the type of flux and the peak temperature. The optimal conditions were: micro-channel tube with 4.2 g/m2 of zinc coating, standard flux, 610 °C peak temperature, 5 °C/min heating rate and 4 min dwell time. The corrosion current density value of the confirmation experiment is in excellent agreement with the predicted value. The electrochemical characterization for selected samples gave indication that the brazing conditions had a more significant effect on the kinetics of the hydrogen evolution reaction than on the kinetics of the metal dissolution reaction.

Determination of wall wear of glassmelting furnaces by a nuclear technique

International Nuclear Information System (INIS)

Harsanyi, Gyoergy; Kodolanyi, Andras; Leitner, Laszlo

1984-01-01

A new in-service inspection technique of glassmelting furnaces is reported. Isotope-labelled refractory tank blocks were prepared, tested experimentally, and built into the furnace. Sup(60)Co isotope tracer was used. The residual wall thickness of the labelled blocks were determined by periodical radiation dose measurements. No environmental or health damage is caused by the specific activity of 3.7 - 4 Bq/g of the labelled furnace blocks, the dose rate in a distance of 1 m from the wall was as low as 0.05 mR/h. (P.J.)

Hopewell Furnace NHS : alternative transportation study

Science.gov (United States)

2009-12-31

This study assesses the potential for an alternative transportation system (ATS) at Hopewell Furnace National Historic Site (NHS). The Volpe Center investigated internal circulation and potential partnerships with local historic, cultural, and recrea...

Numerical investigation on nonlinear effect and vortex formation of oscillatory flow throughout a short tube in a thermoacoustic Stirling engine

Science.gov (United States)

Yang, Peng; Chen, Hui; Liu, Yingwen

2017-06-01

In this paper, a two-dimensional axisymmetric model of a thermoacoustic Stirling engine with a short tube where the cross section narrows has been developed. The transient streamlines and vortex formation through short tubes with different diameters in oscillatory flow have been investigated visually by computational fluid dynamics. Three dimensionless parameters, Reynolds number (Re), Keulegan-Carpenter number (KC), and Womersley number (Wo), are used to describe the flow regime and vortex characteristic throughout the short tube. High Re and Wo numbers indicate that the oscillatory flow develops into the turbulent flow through the short tube. The KC number has a direct effect on the transition of streamlines and the development of the vortex. For a small cross section where KC ≈ 1, streamlines rotate and the vortex forms at both sides of the short tube. The vortex stays in the main flow region, and intensity varies as streamlines are convected downstream. The velocity along the radius presents a Poiseuille profile within the influence of the vortex. For a large cross section where KC < 1, streamlines pass the short tube with little rotation and the vortex disappears in the main flow region and confines near the short tube. The velocity profile tends to be flat. The nonlinear effects including instantaneous pressure drop and power dissipation throughout the short tube are also discussed. It shows that the time averaged pressure drop is generated at the cost of power dissipation. Finally, the "effectiveness" is applied to evaluate the performance of the short tube. The results suggest that increasing the diameter of the short tube is in favor of reducing power dissipation, which is beneficial to improve "effectiveness."

Raman Spectroscopic Study of Carbon Nano tubes Prepared Using Fe/ZnO-Palm Olein-Chemical Vapour Deposition Syazwan

International Nuclear Information System (INIS)

Zobir, A.M.; Abdullah, S.; Rusop, M.; Abdullah, S.; Abu Bakar, S.; Zainal, Z.; Sarijo, S.H.; Rusop, M.

2012-01-01

Multi walled carbon nano tubes (MWCNTs) were synthesized using Fe/ZnO catalyst by a dual-furnace thermal chemical vapor deposition (CVD) method at 800-1000 degree C using nitrogen gas with a constant flow rate of 150 sccm/min as a gas carrier. Palm olein (PO), ferrocene in the presence of 0.05 M zinc nitrate, and a p-type silicon wafer were used as carbon source, catalyst precursor, and sample target, respectively. D, G, and G' bands were observed at 1336-1364, 1559-1680, and 2667-2682 cm -1 , respectively. Carbon nano tubes (CNTs) with the highest degree of crystallinity were obtained at around 8000 degree C, and the smallest diameter of about 2 nm was deposited on the silicon substrate at 1000 degree C.

Effect of Scale on Slab Heat Transfer in a Walking Beam Type Reheating Furnace

OpenAIRE

Man Young Kim

2013-01-01

In this work, the effects of scale on thermal behavior of the slab in a walking-beam type reheating furnace is studied by considering scale formation and growth in a furnace environment. Also, mathematical heat transfer model to predict the thermal radiation in a complex shaped reheating furnace with slab and skid buttons is developed with combined nongray WSGGM and blocked-off solution procedure. The model can attack the heat flux distribution within the furnace and the temperature distribut...

Through-furnace for burning solid organic substances

International Nuclear Information System (INIS)

Kemmler, G.; Schlich, E.

1984-01-01

The through-furnace for burning radio-active organic solid waste consists of a reaction pipe heated from the outside, an input device and an output device. A solid pump is used as the input device, which has a common longitudinal axis with the reaction pipe. The reaction pipe is widened in the transport direction of the combustion pipe, where the angle between the longitudinal axis and the pipe wall is 0.5 to 5 0 . The pipe wall is wholely or partially permeable to gas. The thermal treatment of the solid organic substances can occur by combustion or by pyrohydrolysis or pyrolysis in the through-furnace. (orig./HP) [de

Glass Furnace Project, October 1982-March 1983

International Nuclear Information System (INIS)

Armstrong, K.M.; Klingler, L.M.

1983-01-01

In the Glass Furnace Project currently under way at Mound, a treatment technology for low-level radioactive waste is being evaluated that will combine volume reduction and immobilization in one step. Initial work focused on demonstrating the ability of the furnace to efficiently incinerate nonradioactive, simulated power-plant waste and on determining the adequacy of immobilization in a soda-lime silica matrix. Further evaluation of the system will involve a demonstration of the combustion and containment of radioactive waste. In preparation for this next phase of the program, preliminary investigation and design work were conducted during the past six months. 5 figures, 1 table

A REVIEW OF MILD COMBUSTION AND OPEN FURNACE DESIGN CONSIDERATION

Directory of Open Access Journals (Sweden)

M.M. Noor

2012-12-01

Full Text Available Combustion is still very important to generate energy. Moderate or Intense Low-oxygen Dilution (MILD combustion is one of the best new technologies for clean and efficient combustion. MILD combustion has been proven to be a promising combustion technology in industrial applications with decreased energy consumption due to the uniformity of its temperature distribution. It is clean compared to traditional combustion due to producing low NOx and CO emissions. This article provides a review and discussion of recent research and developments in MILD. The issue and applications are summarized, with some suggestions presented on the upgrading and application of MILD in the future. Currently MILD combustion has been successfully applied in closed furnaces. The preheating of supply air is no longer required since the recirculation inside the enclosed furnace already self-preheats the supply air and self-dilutes the oxygen in the combustion chamber. The possibility of using open furnace MILD combustion will be reviewed. The design consideration for open furnace with exhaust gas re-circulation (EGR was discussed.

Materials analyses of ceramics for glass furnace recuperators

Energy Technology Data Exchange (ETDEWEB)

Weber, G.W.; Tennery, V.J.

1979-11-01

The use of waste heat recuperation systems offers significant promise for meaningful energy conservation in the process heat industries. This report details the analysis of candidate ceramic recuperator materials exposed to simulated industrial glass furnace hot flue gas environments. Several candidate structural ceramic materials including various types of silicon carbide, several grades of alumina, mullite, cordierite, and silicon nitride were exposed to high-temperature flue gas atmospheres from specially constructed day tank furnaces. Furnace charging, operation, and batch composition were selected to closely simulate industrial practice. Material samples were exposed in flues both with and without glass batch in the furnace for times up to 116 d at temperatures from 1150 to 1550/sup 0/C (2100 to 2800/sup 0/F). Exposed materials were examined by optical microscopy, scanning electron microscopy, energy dispersive x-ray analysis, x-ray diffraction, and x-ray fluorescence to identify material degradation mechanisms. The materials observations were summarized as: Silicon carbide exhibited enhanced corrosion at lower temperatures (1150/sup 0/C) when alkalies were deposited on the carbide from the flue gas and less corrosion at higher temperatures (1550/sup 0/C) when alkalies were not deposited on the carbide; alumina corrosion depended strongly upon purity and density and alumina contents less than 99.8% were unsatisfactory above 1400/sup 0/C; and mullite and cordierite are generally unacceptable for application in soda-lime glass melting environments at temperatures above 1100/sup 0/C.

Compacting of fly dusts from cupola and electric arc furnace

Directory of Open Access Journals (Sweden)

D. Baricová

2012-01-01

Full Text Available Recycling and utilization of dust waste is important not only from the point of view of its usage as an alternative source of raw materials, but regarding the environmental problems also. Dust emissions arise from thermal and chemical or physical processes and mechanical actions. Two kinds of fl y dusts from cupola furnaces (hot and cold blast cupola furnace and fl y dust from electric arc furnace were used by experiments. They were pelletized only with addition of water and briquetted with diff erent addition of water glass, bentonite and cement. Quality of briquettes was tested by compression – strength test and by break down test in green state, after drying and afterstoring (1 month.

Mass production of CNTs using CVD multi-quartz tubes

Energy Technology Data Exchange (ETDEWEB)

Yousef, Samy; Mohamed, Alaa [Dept. of Production Engineering and Printing Technology, Akhbar Elyom Academy, Giza (Egypt)

2016-11-15

Carbon nanotubes (CNTs) have become the backbone of modern industries, including lightweight and heavy-duty industrial applications. Chemical vapor deposition (CVD) is considered as the most common method used to synthesize high yield CNTs. This work aims to develop the traditional CVD for the mass production of more economical CNTs, meeting the growing CNT demands among consumers by increasing the number of three particular reactors. All reactors housing is connected by small channels to provide the heat exchange possibility between the chambers, thereby decreasing synthesis time and reducing heat losses inside the ceramic body of the furnace. The novel design is simple and cheap with a lower reacting time and heat loss compared with the traditional CVD design. Methane, hydrogen, argon, and catalyzed iron nanoparticles were used as a carbon source and catalyst during the synthesis process. In addition, CNTs were produced using only a single quartz tube for comparison. The produced samples were examined using XRD, TEM, SEM, FTIR, and TGA. The results showed that the yield of CNTs increases by 287 % compared with those synthesized with a single quartz tube. Moreover, the total synthesis time of CNTs decreases by 37 % because of decreased heat leakage.

Heat pipes and use of heat pipes in furnace exhaust

Science.gov (United States)

Polcyn, Adam D.

2010-12-28

An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

Production of blast furnace coke from soft brown coal

Energy Technology Data Exchange (ETDEWEB)

Scholz, G.; Wundes, H.; Schkommodau, F.; Zinke, H.-G. (VEB Gaskombinat Schwarze Pumpe (German Democratic Republic))

1988-01-01

Reviews experimental production and utilization of high quality brown coal coke in the GDR during 1985 and 1986. The technology of briquetting and coking brown coal dust is described; the superior parameters of produced coke quality are listed in comparison to those of regular industrial coke made from brown and black coal. Dust emission from high quality brown coal coke was suppressed by coke surface treatment with dispersion foam. About 4,200 t of this coke were employed in black coal coke substitution tests in a blast furnace. Substitution rate was 11%, blast furnace operation was positive, a substitution factor of 0.7 t black coal coke per 1 t of brown coal coke was calculated. Technology development of high quality brown coal coke production is regarded as complete; blast furnace coke utilization, however, requires further study. 8 refs.

Computational Modeling of Arc-Slag Interaction in DC Furnaces

Science.gov (United States)

Reynolds, Quinn G.

2017-02-01

The plasma arc is central to the operation of the direct-current arc furnace, a unit operation commonly used in high-temperature processing of both primary ores and recycled metals. The arc is a high-velocity, high-temperature jet of ionized gas created and sustained by interactions among the thermal, momentum, and electromagnetic fields resulting from the passage of electric current. In addition to being the primary source of thermal energy, the arc jet also couples mechanically with the bath of molten process material within the furnace, causing substantial splashing and stirring in the region in which it impinges. The arc's interaction with the molten bath inside the furnace is studied through use of a multiphase, multiphysics computational magnetohydrodynamic model developed in the OpenFOAM® framework. Results from the computational solver are compared with empirical correlations that account for arc-slag interaction effects.

Model technique for aerodynamic study of boiler furnace

Energy Technology Data Exchange (ETDEWEB)

1966-02-01

The help of the Division was recently sought to improve the heat transfer and reduce the exit gas temperature in a pulverized-fuel-fired boiler at an Australian power station. One approach adopted was to construct from Perspex a 1:20 scale cold-air model of the boiler furnace and to use a flow-visualization technique to study the aerodynamic patterns established when air was introduced through the p.f. burners of the model. The work established good correlations between the behaviour of the model and of the boiler furnace.

Heating characteristics of billet in a walking hearth type reheating furnace

International Nuclear Information System (INIS)

Emadi, Ali; Saboonchi, Ahmad; Taheri, Mahdi; Hassanpour, Saeid

2014-01-01

The heating characteristics of billet in a walking hearth type reheating furnace were studied by developing a mathematical heat transfer model. Radiation calculations were conducted by means of zone method and considering all radiation exchange paths. The weighted-sum-of-gray-gas-model was used for better accuracy of gas radiation prediction. Convective heat flux was calculated by considering suitable value of convective heat transfer coefficient at any location of the furnace. The model was substantiated through its comparison to experimental data. A comparison was drawn to evaluate the effect of constant and variable convective coefficient on convective flux distribution and billet thermal behavior. The effect of furnace wall's emissivity of each zone and whole of the furnace on the billet thermal behavior was investigated. The obtained results revealed that by increasing furnace wall's emissivity for a determined residence time, billet's temperature in primary zones rises but it has no significant effect on its final temperature. However, by increasing wall's emissivity from 0.7 to 0.95, the residence time can be declined by about 5%. Moreover, emissivity increase in non-firing and preheating zones as compared to heating and soaking zones has greater impact on the billet thermal behavior. -- Highlights: • 3D radiation modeling by considering all possible paths of radiation exchange. • Using WSGG model for better prediction of gas radiation. • Using non-constant convection coefficient to consider variation of gas mass flow. • Investigation of effect of convection coefficient on billet temperature behavior. • Investigation of wall emissivity of furnace zones

Numerical analysis of flow instability in the water wall of a supercritical CFB boiler with annular furnace

Science.gov (United States)

Xie, Beibei; Yang, Dong; Xie, Haiyan; Nie, Xin; Liu, Wanyu

2016-08-01

In order to expand the study on flow instability of supercritical circulating fluidized bed (CFB) boiler, a new numerical computational model considering the heat storage of the tube wall metal was presented in this paper. The lumped parameter method was proposed for wall temperature calculation and the single channel model was adopted for the analysis of flow instability. Based on the time-domain method, a new numerical computational program suitable for the analysis of flow instability in the water wall of supercritical CFB boiler with annular furnace was established. To verify the code, calculation results were respectively compared with data of commercial software. According to the comparisons, the new code was proved to be reasonable and accurate for practical engineering application in analysis of flow instability. Based on the new program, the flow instability of supercritical CFB boiler with annular furnace was simulated by time-domain method. When 1.2 times heat load disturbance was applied on the loop, results showed that the inlet flow rate, outlet flow rate and wall temperature fluctuated with time eventually remained at constant values, suggesting that the hydrodynamic flow was stable. The results also showed that in the case of considering the heat storage, the flow in the water wall is easier to return to stable state than without considering heat storage.

NEDO project reports. High performance industrial furnace development project - High temperature air combustion

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-21

For the purpose of reducing energy consumption, a NEDO project 'Developmental research on high efficiency industrial furnaces' was carried out from FY 1993 to FY 1999 by The Japan Industrial Furnaces Manufacturers Association, and the paper outlined the details of the project. Industrial furnaces handled in this R and D can bring 30% reduction of the energy consumption and approximately 50% NOx reduction, and were given the 9th Nikkei global environmental technology prize. In the study of combustion phenomena of high temperature air combustion, the paper arranged characteristics of flame, the base of gaseous fuel flame, the base of liquid fuel flame, the base of solid fuel flame, etc. Concerning high temperature air combustion models for simulation, fluid dynamics and heat transfer models, and reaction and NOx models, etc. As to impacts of high temperature air combustion on performance of industrial furnaces, energy conservation, lowering of pollution, etc. In relation to a guide for the design of high efficiency industrial furnaces, flow charts, conceptual design, evaluation method for heat balance and efficiency using charts, combustion control system, applicability of high efficiency industrial furnaces, etc. (NEDO)

NEDO project reports. High performance industrial furnace development project - High temperature air combustion

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-21

For the purpose of reducing energy consumption, a NEDO project 'Developmental research on high efficiency industrial furnaces' was carried out from FY 1993 to FY 1999 by The Japan Industrial Furnaces Manufacturers Association, and the paper outlined the details of the project. Industrial furnaces handled in this R and D can bring 30% reduction of the energy consumption and approximately 50% NOx reduction, and were given the 9th Nikkei global environmental technology prize. In the study of combustion phenomena of high temperature air combustion, the paper arranged characteristics of flame, the base of gaseous fuel flame, the base of liquid fuel flame, the base of solid fuel flame, etc. Concerning high temperature air combustion models for simulation, fluid dynamics and heat transfer models, and reaction and NOx models, etc. As to impacts of high temperature air combustion on performance of industrial furnaces, energy conservation, lowering of pollution, etc. In relation to a guide for the design of high efficiency industrial furnaces, flow charts, conceptual design, evaluation method for heat balance and efficiency using charts, combustion control system, applicability of high efficiency industrial furnaces, etc. (NEDO)

Improving Gas Furnace Performance: A Field and Laboratory Study at End of Life

Energy Technology Data Exchange (ETDEWEB)

Brand, L. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States); Yee, S. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States); Baker, J. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)

2015-02-01

In 2010, natural gas provided 54% of total residential space heating energy the U.S. on a source basis, or 3.5 Quadrillion Btu. Natural gas burned in furnaces accounted for 92% of that total, and boilers and other equipment made up the remainder. A better understanding of installed furnace performance is a key to energy savings for this significant energy usage. In this project, the U.S. Department of Energy Building America team Partnership for Advanced Residential Retrofit examined the impact that common installation practices and age-induced equipment degradation may have on the installed performance of natural gas furnaces over the life of the product, as measured by steady-state efficiency and annual efficiency. The team identified 12 furnaces of various ages and efficiencies that were operating in residential homes in the Des Moines, Iowa, metropolitan area and worked with a local heating, ventilation, and air conditioning contractor to retrieve furnaces and test them at the Gas Technology Institute laboratory for steady-state efficiency and annual efficiency. Prior to removal, system airflow, static pressure, equipment temperature rise, and flue loss measurements were recorded for each furnace as installed in the house.

Combustion of Solid Fuel in a Vortex Furnace with Counter-swirling Flows

Directory of Open Access Journals (Sweden)

Redko A.A.

2017-12-01

Full Text Available The results of computer simulation of the processes of incineration of low-grade solid fuel-pulverized peat with a moisture content of 40%, an ash content of 6% are given. It has been determined the fields of distribution of temperature, velocity of gases and particles in the volume and at the outlet from the furnace. The three-dimensional temperature distribution in the combustion chamber indicates high-temperature combustion of peat particles at temperatures above 1700°C with liquid ash removal in the lower part of the furnace. It has been determined that when the furnace is cooled, it is not ensured combustion of the fuel completely. The value of the swirling flow rate at the outlet from the furnace (up to 370 m/s ensures the efficiency of separation of fuel particles, reducing heat losses from mechanical underburning. It is determined that the concentration of oxygen is close to zero over the entire height of the furnace, at an outlet from the furnace the oxygen concentration is 5...6%, since oxygen is supplied with excess (αв=1,2. The results of a numerical study showed that the diameter of peat particles affects the process of their combustion: coke particles with an initial diameter of 25 mkm to 250 mkm burn out by 96%. With an increase in particle diameter up to 1000 mkm, the degree of burn-out of coke decreases, but at the same time their removal decreases. It is shown that the furnace ensures the completeness of combustion of peat particles of peat 99.8%, volatiles is 100%.

Thermal design of a pressure electroslag remelting furnace applied for 5

International Nuclear Information System (INIS)

Cruz M, J.P.

1999-01-01

Actual work defines the thermal design methodology for pressure electroslag remelting furnaces (P ESR) of variable capacity, applied for 5 Kg. It begins with classification and description of secondary refining furnaces, after PESR process and the concept of thermal design are described. Next, in base of the steel weight to remelt (5 Kg); ingot, crucible and electrode dimensions are obtained. These elements will be inside of pressure vessel whose thickness are determined according to ASME Code (Section 8, Division 1, U G-27). It was developed a computer program, where the furnace capacity can be modified, so like other conditions, and display principal dimensions of the furnace. Current and voltage are obtained from the heat necessary to remelt the ingot and the heat transfer in the crucible, is analysed because of it is the most critical element. It was selected too the equipment to registry temperatures and pressure in base of thermocouple characteristics. (Author)

Condensation of pure and near-azeotropic refrigerants in microfin tubes: A new computational procedure

Energy Technology Data Exchange (ETDEWEB)

Cavallini, A; Del Col, D; Mancin, S; Rossetto, L [Dipartimento di Fisica Tecnica, University of Padova, Via Venezia 1, Padova 35131 (Italy)

2009-01-15

Microfin tubes are widely used in air cooled and water cooled heat exchangers for heat pump and refrigeration applications during condensation or evaporation of refrigerants. In order to design heat exchangers and to optimize heat transfer surfaces, accurate procedures for computing pressure drops and heat transfer coefficients are necessary. This paper presents a new simple model for the prediction of the heat transfer coefficient to be applied to condensation in horizontal microfin tubes of halogenated and natural refrigerants, pure fluids or nearly azeotropic mixtures. The updated model accounts for refrigerant physical properties, two-phase flow patterns in microfin tubes and geometrical characteristics of the tubes. It is validated against a data bank of 3115 experimental heat transfer coefficients measured in different independent laboratories all over the world including diverse inside tube geometries and different condensing refrigerants among which R22, R134a, R123, R410A and CO{sub 2}. (author)

Fracture toughness of irradiated Zr-2.5Nb pressure tube from Indian PHWR

Science.gov (United States)

Shah, Priti Kotak; Dubey, J. S.; Shriwastaw, R. S.; Dhotre, M. P.; Bhandekar, A.; Pandit, K. M.; Anantharaman, S.; Singh, R. N.; Chakravartty, J. K.

2015-03-01

Fracture toughness of irradiated Zr-2.5Nb alloy pressure tube, fabricated by the cold pilgering and stress relieving route, was evaluated using disk compact tension type specimens. These specimens were punched out from the irradiated pressure tube (S-07), which was in service for about 8 effective full power years of reactor operation in the Kakrapar Atomic Power Station-2 (KAPS-2). The tests were carried out remotely inside a lead shielded enclosure. Crack growth during the test was measured using the direct current potential drop technique. The irradiated pressure tube showed low fracture toughness at 25 °C. The fracture toughness increased with increase in temperature up to 250 °C but was practically unaffected with further increase in temperature up to 300 °C. This paper discusses the fracture behavior of irradiated Indian pressure tube material and compares it with other data available.

Radiometric report for a blast furnace tracing with radioactive isotopes

International Nuclear Information System (INIS)

Tanase, G.; Tanase, M.

1995-01-01

One of the methods to monitor refractory wall of blast furnace is its tracing with radioactive isotopes. The tracer isotope can be detected by two ways: the external dosimetric measurement at the armour of the blast furnace and/or the radiometric measurement of the iron sample charge by charge. Any change in radiometric situation of tracer radioisotope is recorded in a radiometric report. This paper presents an original concept of radiometric report based upon PARADOX and CORELDRAW soft kits. Their advantage are: quick and easy changes, easy recording of current radioactivity of tracer isotope, short history of changes, visual mapping of the tracer isotope and others. In this way we monitored 6 blast furnaces and more than 180 radioactive sources

Simulation for the powder movement and accumulation in the lower part of blast furnace

Energy Technology Data Exchange (ETDEWEB)

Sugiyama, Takashi [Mineral Resources Research Center, Nippon Steel Technoresearch, Futtsu-shi Chiba (Japan)

1998-12-31

The behavior of unburnt char and coke powder in the blast furnace becomes material for discussion with the increase in injection rate of pulverized coal into the blast furnace. An analysis was made as to the simulation of powder accumulation at the deadman and dripping zone of blast furnace by using a powder/gas two-phases flow experimental data. When an excessive powder has penetrated at a low gas velocity, it brings an increment in holdup and the controlling factors are powder/gas ratio and gas velocity. An empirical formula used for estimating the powder hold-up in the blast furnace internal conditions has proposed based on similarity. The controlling {pi} numbers are Floude number, powder/gas ratio and particle diameter ratio of powder/lump. This empirical formular was connected with Blast Furnace Total Model `BRIGHT` for the simulation of powder amount distribution in the lower part of blast furnace. When Powder diameter Dk exceeds 100 {mu} and gas velocity becomes lower than 0.7m/s at PC1OOkg/T, the powder tends to accumulate in the deadman. These results was available for the decision of optimum blast conditions and optimum powder diameter in the high amount of pulverized coal injection to the blast furnace. (author) 10 refs.

Simulation for the powder movement and accumulation in the lower part of blast furnace

Energy Technology Data Exchange (ETDEWEB)

Sugiyama, Takashi [Mineral Resources Research Center, Nippon Steel Technoresearch, Futtsu-shi Chiba (Japan)

1997-12-31

The behavior of unburnt char and coke powder in the blast furnace becomes material for discussion with the increase in injection rate of pulverized coal into the blast furnace. An analysis was made as to the simulation of powder accumulation at the deadman and dripping zone of blast furnace by using a powder/gas two-phases flow experimental data. When an excessive powder has penetrated at a low gas velocity, it brings an increment in holdup and the controlling factors are powder/gas ratio and gas velocity. An empirical formula used for estimating the powder hold-up in the blast furnace internal conditions has proposed based on similarity. The controlling {pi} numbers are Floude number, powder/gas ratio and particle diameter ratio of powder/lump. This empirical formular was connected with Blast Furnace Total Model `BRIGHT` for the simulation of powder amount distribution in the lower part of blast furnace. When Powder diameter Dk exceeds 100 {mu} and gas velocity becomes lower than 0.7m/s at PC1OOkg/T, the powder tends to accumulate in the deadman. These results was available for the decision of optimum blast conditions and optimum powder diameter in the high amount of pulverized coal injection to the blast furnace. (author) 10 refs.

Monitoring device for glass melting furnace

International Nuclear Information System (INIS)

Endo, Noboru; Asano, Naoki; Higuchi, Tatsuo; Koyama, Mayumi; Hanado, Shinji.

1995-01-01

The device of the present invention can monitor, from a remote place, a liquid surface in a glass melting furnace for use in a solidification treatment, for example, of high level radioactive wastes. Namely, a vertical sleeve is disposed penetrating a ceiling wall of a melting vessel. A reflection mirror is disposed above the vertical sleeve and flex an optical axis. A monitoring means is disposed on the optical axis of the reflecting mirror at a spaced position. The monitoring means may have an optical telescopic means, a monitoring camera by way of a half mirror and an illumination means. The reflection mirror may be made of a metal. The monitoring device thus constituted suffer from no effects of high temperature and high radiation dose rate, thereby enabling to easily monitor the liquid surface in the melting furnace. (I.S.)

Plan for the Startup of HA-21I Furnace Operations at the Plutonium Finishing Plant (PFP)

International Nuclear Information System (INIS)

WILLIS, H.T.

2000-01-01

Achievement of Thermal Stabilization mission elements require the installation and startup of three additional muffle furnaces for the thermal stabilization of plutonium and plutonium bearing materials at the Plutonium Finishing Plant (PFP). The release to operate these additional furnaces will require an Activity Based Startup Review. The conduct of the Activity Based Startup Review (ABSR) was approved by Fluor Daniel Hanford on October 15, 1999. This plan has been developed with the objective of identifying those activities needed to guide the controlled startup of five furnaces from authorization to unrestricted operations by adding the HA-211 furnaces in an orderly and safe manner after the approval to Startup has been given. The Startup Plan provides a phased approach that bridges the activities between the completion of the Activity Based Startup Review authorizing the use of the three additional furnaces and the unrestricted operation of the five thermal stabilization muffle furnaces. The four phases are: (1) the initiation of five furnace operations using three empty (simulated full) boat charges from HA-211 and two full charges from HC-21C; (2) three furnace operations (one full charge from HA-211 and two full charges from HC-21C); (3) four furnace operations (two full charges from HA-211 and two full charges from HC-21C); and (4) integrated five furnace operations and unrestricted operations. Phase 1 of the Plan will be considered as the cold runs. This Plan also provides management oversight and administrative controls that are to be implemented until unrestricted operations are authorized. It also provides a formal review process for ensuring that all preparations needed for full five furnace operations are completed and formally reviewed prior to proceeding to the increased activity levels associated with five furnace operations. Specific objectives include: (1) To ensure that activities are conducted in a safe manner. (2) To provide supplemental

The influence of the space between the billets on the productivity of a continuous walking-beam furnace

Energy Technology Data Exchange (ETDEWEB)

Jaklic, A. [Institute of Metals and Technology, Ljubljana (Slovenia); Kolenko, T. [University of Ljubljana (Slovenia). Faculty of Natural Science and Technology; Zupancic, B. [University of Ljubljana (Slovenia). Faculty of Electrical Engineering

2005-04-01

This paper presents a study of the influence of the space between billets on the productivity of a continuous walking-beam furnace. The study was performed using a simulation model of a billet-reheating process for three different billet dimensions. The simulation model considered the exact geometry of the furnace enclosure, including the geometry of the billets inside the furnace. A view-factor matrix of the furnace enclosure was determined using the Monte Carlo method. The heat exchange between the furnace gas, the furnace wall and the billet's surface was calculated using a three-temperature model. The temperature of the furnace floor was determined using a heat-balance equation, and the heat conduction in the billets was calculated using the 3D finite-difference method. The model was validated using measurements from trailing thermocouples positioned in the test billet during the reheating process in the furnace. (author)

Thermal analysis of a helium-cooled, tube-bank blanket module for a tandem mirror fusion reactor

International Nuclear Information System (INIS)

Werner, R.W.

1983-01-01

A blanket module concept for the central cell of a tandem mirror reactor is described which takes advantage of the excellent heat transfer and low pressure drop characteristics of tube banks in cross-flow. The blanket employs solid Li 2 O as the tritium breeding material and helium as the coolant. The lithium oxide is contained in tubes arranged within the submodules as a two-pass, cross-flow heat exchanger. Primarily, the heat transfer and thermal-hydraulic aspects of the blanket design study are described in this paper. In particular, the analytical model used for selection of the best tube-bank design parameters is discussed in some detail

Thermal analysis of a helium-cooled, tube-bank blanket module for a tandem-mirror fusion reactor

International Nuclear Information System (INIS)

Werner, R.W.; Hoffman, M.A.; Johnson, G.L.

1983-01-01

A blanket module concept for the central cell of a tandem mirror reactor is described which takes advantage of the excellent heat transfer and low pressure drop characteristics of tube banks in cross-flow. The blanket employs solid Li 2 O as the tritium breeding material and helium as the coolant. The lithium oxide is contained in tubes arranged within the submodules as a two-pass, cross-flow heat exchanger. Primarily, the heat transfer and thermal-hydraulic aspects of the blanket design study are described in this paper. In particular, the analytical model used for selection of the best tube-bank design parameters is discussed in some detail

Gastrostomy Tube (G-Tube)

Science.gov (United States)

... any of these problems: a dislodged tube a blocked or clogged tube any signs of infection (including redness, swelling, or warmth at the tube site; discharge that's yellow, green, or foul-smelling; fever) excessive bleeding or drainage from the tube site severe abdominal pain lasting ...

Modernization of two gas-fired shaft annealing furnaces

Energy Technology Data Exchange (ETDEWEB)

Barthof, G.; Porst, G.; Raczek, S.

1986-04-01

The objective was to modernize two existing shaft-type annealing furnaces used for the heat treatment of grey iron castings with the aim of reducing the consumption of gaseous fuel, minimize the formation of scale, decrease maintenance expense and apply more automatic control to the annealing process. This was to be achieved by an optimum combination of new types of construction materials and advanced firing and control equipment. The author describes the furnace in its condition prior to and after reconstruction. The operating results obtained after reconstruction were found to justify the costs incurred. The payback period is roughly one year.

Use of coal-water mixtures in blast furnaces

Energy Technology Data Exchange (ETDEWEB)

Malgarini, G; Giuli, M; Davide, A; Carlesi, C [Centro Sviluppo Materiali, Rome (Italy); Italsider, Genoa [Italy; Deltasider, Piombino [Italy

1989-03-01

At the present time, an ironworks blast furnace employing a pulverized coal injection (PCI) system is in operation at the Piombino Works (Italy). A wide development, within this industry, of PCI techniques is expected in the near future to limit, as much as possible, the rebuilding of coke ovens. Research activities and industrial trials aimed at maximizing the use of coal injection into blast furnaces are in course of development. This paper uses flowsheets to illustrate such a system and provides graphs to indicate the economic convenience of PCI systems as compared with systems using naphtha as an injected fuel.

Joule-heated glass-furnace system for the incineration of low-level radioactive wastes

International Nuclear Information System (INIS)

Armstrong, K.M.; Klingler, L.M.; Doty, J.W.; Kramer, D.P.

1982-01-01

For the past 1-1/2 years, Mound has been preparing and evaluating a commercially available joule-heated glass furnace unit, coupled with a wet scrubbing system. The purpose of the glass furnace evaluation is to advance and document incinerator technology for such combustibles as solids, resins, and sludges, and to develop a stable waste form for subsequent disposal. Four (4) waste nonradioactive types were selected to determine the combustion efficiency of the furnace unit: (1) dry solid waste composed of paper, plastics, rubber, and cloth, (2) ion exchange resin of both the anionic and cationic type, (3) filter sludge composed of diatomaceous earth, organic cellulosic filter aid, and powdered ion exchange resin, and (4) cartridge filters having glass and plastic filter surfaces and nonmetallic cores. When completed, the combustion efficiency experiments for the proposed nonradioactive waste-types revealed the ability of the furnace to easily incinerate waste at feedrates of up to 150 lb/hr. During the course of the experiments, combustibles in the offgas remained consistently low, suggesting excellent combustion efficiency. Furthermore, ash produced by the combustion process was effectively incorporated into the melt by convective currents in the glass. Future work on the glass furnace incinerator will include spiking the waste to determine radioisotope behavior in the furnace

Atomization mechanisms for barium in furnace atomic absorption spectrometry

International Nuclear Information System (INIS)

Styris, D.L.

1984-01-01

Atomic absorption spectrometry and mass spectrometry are used simultaneously in order to elucidate atomization mechanisms of barium dichloride in pyrolytic graphite, vitreous carbon, and tantalum furnaces. Gas-phase barium dicarbide is observed to appear concurrently with the free barium. Barium oxide and barium dihydroxide precursors appear with the chlorides. Surface reactions involving species that are absorbed on the various furnaces are postulated to explain the appearances of the species that are observed in the gas phase. 49 references, 4 figures, 1 table

Automation Activator of Hydrogen Gas Inlet Valve on Reduction Furnace ME-11

International Nuclear Information System (INIS)

Achmad Suntoro

2007-01-01

Operational of hydrogen inlet valve of the reduction furnace ME-11 was actuated manually by furnace operator if all its requirements have been fulfilled. Automation of the valve has been constructed as an additional option of the furnace operating system, in which any interruption by the existing manual system by the operator is still valid even though the automatic option is being used. This paper describes the information concerning the automation construction and its logical status of control in the form of its finite state machine. This automation system has been tested successfully. (author)

Evaluation of refractory lining wear of Companhia Siderurgica Nacional (CSN) blast furnaces

International Nuclear Information System (INIS)

Santos, N.J. dos; Mello, A.H.B. de; Pereira, C.L.; Paula Sarkis, D. de; Martins Filho, D.I.; Banados Perez, H.E.; Carvalho, G.; Daltro, T.F.L.

1984-01-01

The blast furnace refractory linings are submitted to unfavourable conditions such as alkalis attack, temperature, top pressure, abrasion and so forth... After studies on distribution and installation of radioactive sources with low activities in the refractory lining, it was possible to develop a new technique of thickness evaluation and attendance of wearing in the furnace lining. The viability analysis, simulated laboratory tests, localization, identification, installations and periodical measurements of the radioactive sources are described, as well the results obtained on the present campaign of CSN Blast Furnaces. (Author) [pt

Effect of tube bank inclination on the thermal hydraulic performance of air-cooled heat exchangers

International Nuclear Information System (INIS)

Monheit, M.; Freim, J.

1987-01-01

This paper compares the experimental thermal hydraulic performance of an inclined tube bundle of staggered high finned tubes with that of the same bank in cross flow. The data are shown on a relative basis with the conventional cross-flow arrangement used as the reference layout. The results, presented as plots of heat transfer coefficient and pressure drop per row versus face velocity, are compared with other published data for bare and extended-surface tube banks. Correction factors that account for the deviation from cross-flow performance are presented. Estimated savings in plot area are shown for typical cases. Some possible cost reduction opportunities in specific fields of application are also suggested

The electrical characteristics of copper slags in a 270 kVA DC arc furnace

International Nuclear Information System (INIS)

Derin, Bora; Sahin, Filiz Cinar; Yucel, Onuralp

2003-01-01

The electrical resistance of slags is the main criteria to determine the design and the operation conditions of slag resistance furnace (SRF) depending on temperature and composition. In this study, a 270 kVA DC electric arc furnace were used to determine the electrical characteristic of molten ancient copper slags. The specific conductivity of the slag was estimated by using furnace geometric factor given in the literature as an empirical formula and by using furnace resistance measured during smelting of the copper slag with or without different additives such as coke, CaO and Al 2 O 3 . (Original)

76 FR 56339 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Furnaces and...

Science.gov (United States)

2011-09-13

...) which covered furnaces (but not boilers), and it establishes amended energy efficiency standards for... Database for Residential Furnaces and Boilers,\\7\\ and the Consortium for Energy Efficiency's Qualifying...\\ Consortium of Energy Efficiency, Qualifying Furnace and Boiler List (2010) (Available at: http://www.cee1.org...

Thermal design, rating and second law analysis of shell and tube condensers based on Taguchi optimization for waste heat recovery based thermal desalination plants

Science.gov (United States)

Chandrakanth, Balaji; Venkatesan, G; Prakash Kumar, L. S. S; Jalihal, Purnima; Iniyan, S

2018-03-01

The present work discusses the design and selection of a shell and tube condenser used in Low Temperature Thermal Desalination (LTTD). To optimize the key geometrical and process parameters of the condenser with multiple parameters and levels, a design of an experiment approach using Taguchi method was chosen. An orthogonal array (OA) of 25 designs was selected for this study. The condenser was designed, analysed using HTRI software and the heat transfer area with respective tube side pressure drop were computed using the same, as these two objective functions determine the capital and running cost of the condenser. There was a complex trade off between the heat transfer area and pressure drop in the analysis, however second law analysis was worked out for determining the optimal heat transfer area vs pressure drop for condensing the required heat load.

Thermohydraulic performance comparision of compound inserts for a turbulent flow through a circular tube

Directory of Open Access Journals (Sweden)

Kapse Arvind A.

2017-01-01

Full Text Available Heat transfer and pressure drop characteristics of three different passive inserts are experimentally investigated for individual and compound insertion. Insert cross-section is altered along the length of test section for compound insertion. Test runs were conducted in a concentric circular tube in tube heat exchanger in the Reynolds number range of 8000 to 32000 with water as a working fluid. Enhancements in Nusselt number and friction factors are reported to be in the range of 38-234% and 55-524%, respectively, over plain tube. The average performance ratios based on equal pumping power are also reported and found in the range of 0.63-1.53. Based on experimental results, optimum combination for compound insertion is proposed.

75 FR 41102 - Energy Conservation Program: Energy Conservation Standards for Furnace Fans: Reopening of Public...