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Mixing Chamber (mixing + chamber)
Selected AbstractsHydrogen Production via Autothermal Reforming of Diesel FuelFUEL CELLS, Issue 3 2004J. Pasel Abstract Hydrogen, for the operation of a polymer electrolyte fuel cell, can be produced by means of autothermal reforming of liquid hydrocarbons. Experiments, especially with ATR 4, which produces a molar hydrogen stream equivalent to an electrical power in the fuel cell of 3,kW, showed that the process should be preferably run in the temperature range between 700,° and 850,°. This ensures complete hydrocarbon conversion and avoids the formation of considerable amounts of methane and organic compounds in the product water. Experiments with commercial diesel showed promising results but insufficient long-term stability. Experiments concerning the ignition of the catalytic reaction inside the reformer proved that within 60,s after the addition of water and hydrocarbons the reformer reached 95% of its maximum molar hydrogen flow. Measurements, with respect to reformer start-up, showed that it takes approximately 7,min. to heat up the monolith to a temperature of 340,° using an external heating device. Modelling is performed, aimed at the modification of the mixing chamber of ATR Type 5, which will help to amend the homogeneous blending of diesel fuel with air and water in the mixing chamber. [source] Experimental investigation of an ejector refrigerator: Effect of mixing chamber geometry on system performanceINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2001S. Aphornratana Abstract This paper describes an experimental study of an ejector refrigeration cycle using R11 as the working fluid. The system was tested with boiler temperature from 100 to 110°C, the condenser temperature from 35 to 41°C, and the evaporator temperature up to 12°C. Two different mixing chambers with throat diameter of 8 mm were used. Choking of the fluid was always found in the first mixing chamber, but not in the second one. The system was more flexible to operate when there was no choking in the mixing chamber. A cooling temperature as low as ,5°C could be obtained with COP between 0.1 and 0.25 and cooling capacity between 500 and 1700 W. Copyright © 2001 John Wiley & Sons, Ltd. [source] CFD modelling and experimental investigation of an ejector refrigeration system using methanol as the working fluidINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 2 2001S. B. Riffat Abstract This paper presents results of computational fluid dynamic (CFD) analysis and experimental investigation of an ejector refrigeration system using methanol as the working fluid. The CFD modelling was used to investigate the effect of the relative position of the primary nozzle exit within the mixing chamber on the performance of the ejector. The results of the CFD were used to obtain the optimum geometry of the ejector, which was then used to design, construct and test a small-scale experimental ejector refrigeration system. Methanol was used as the working fluid, as it has the advantage of being an ,environmentally friendly' refrigerant that does not contribute to global warming and ozone layer depletion. In addition, use of methanol allows the ejector refrigeration system to produce cooling at temperatures below the freezing point of the water, which of course would not be possible with a water ejector refrigeration system. CFD results showed that positioning the nozzle exit at least 0.21 length of the mixing chamber throat's diameter upstream of the entrance of the mixing chamber gave better performance than pushing it into the mixing chamber. Experimental values of coefficient of performance (COP) between 0.2 and 0.4 were obtained at operating conditions achievable using low-grade heat such as solar energy and waste heat. Copyright © 2001 John Wiley & Sons, Ltd. [source] Dynamic behavior of the flow field in a RIM machine mixing chamberAICHE JOURNAL, Issue 6 2009Ricardo J. Santos Abstract Dynamic behavior of the flow field in a Reaction Injection Molding, RIM, machine mixing chamber, having dimensions typically used in industrial machines, is studied from dynamic velocity data of Laser Doppler Anemometry, LDA, measurements and Computational Fluid Dynamics, CFD, simulations with a 2D model. This study is based on the spectral analysis of the dynamic flow field data. The typical frequencies, in the reactor flow field, are identified and its values are related to the identified flow structures. The differences between the typical frequencies from experiments and simulations are observed and justified on the basis of the 2D representation of a 3D cylindrical geometry. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Improving the properties of LDPE/glass fiber composites with silanized-LDPEPOLYMER COMPOSITES, Issue 7 2009Felipe W. Fabris Low density polyethylene (LDPE) is a widely used thermoplastic. The dispersion of inorganic fillers in thermoplastic matrices such as polyethylene has been largely employed to improve some of its properties. However, interaction between both components is a major issue so the presence of a coupling agent is usually necessary to increase the interaction among the phases. In this study, LDPE chemically modified with vinyltriethoxysilane (VTES) was used as a coupling agent in glass fiber-reinforced LDPE. The composites were prepared in a mixing chamber and subsequently analyzed by tensile tests, rotational rheometry, and scanning electron microscopy (SEM). The mechanical properties were significantly increased by the use of small amounts of the coupling agent. Moreover, the rheological behavior and the SEM micrographs showed higher interaction between the matrix and the reinforcing phase in the composites containing LDPE modified with VTES, confirming the suitability of using this coupling agent in these systems. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] Template Refolding by Use of an Antibody-Coupled Affinity ColumnCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 11 2005S. Katoh Abstract To improve the efficiency and throughput, the biointeraction between an antigen and antibody was used for refolding in a packed column, in which an antibody against carbonic anhydrase coupled on a gel support was used as a template ligand. A denatured solution of CAB was mixed with a refolding buffer in a mixing chamber, and was supplied to the antibody-coupled column for refolding. Higher refolding efficiencies were obtained in the column than by the batch dilution method at relatively low concentrations of denaturant. By increasing the adsorption capacity of the column, the efficiency of refolding, as well as the throughput, could be increased. [source] Experimental investigation of an ejector refrigerator: Effect of mixing chamber geometry on system performanceINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2001S. Aphornratana Abstract This paper describes an experimental study of an ejector refrigeration cycle using R11 as the working fluid. The system was tested with boiler temperature from 100 to 110°C, the condenser temperature from 35 to 41°C, and the evaporator temperature up to 12°C. Two different mixing chambers with throat diameter of 8 mm were used. Choking of the fluid was always found in the first mixing chamber, but not in the second one. The system was more flexible to operate when there was no choking in the mixing chamber. A cooling temperature as low as ,5°C could be obtained with COP between 0.1 and 0.25 and cooling capacity between 500 and 1700 W. Copyright © 2001 John Wiley & Sons, Ltd. [source] A numerical study of mixing in a microchannel with circular mixing chambersAICHE JOURNAL, Issue 9 2009Mubashshir Ahmad Ansari Abstract The mixing of fluids in a microchannel is numerically investigated using three-dimensional Navier,Stokes equations. The microchannel has circular mixing chambers that are designed to create a self-circulating flow that operates at low Reynolds numbers. The investigations have been performed on a design that comprises of four circular mixing chambers that are joined together with constriction channels. The study has been carried out in two parts. Firstly, the mixing and the flow field are analyzed for a wide range (1,250) of the Reynolds number. Secondly, the effects of two design parameters, namely, the ratio, w/d, of the width of the constriction channel to the diameter of the circular chamber, and the angle, ,, between the outer walls of the chamber and the connection channel, on the mixing and the flow field have been evaluated. The mixing has been evaluated using a parameter, called mixing index, which is based on the variance of the mass fraction. The mixing index at the end of the device increases rapidly with the Reynolds number. The presence of a flow recirculation zone in the circular chamber is found to be effective in enhancing mixing, especially for larger Reynolds numbers. The mixing performance improves with an increase in ,, and with a decrease in w/d. The characteristics of the pressure drop have also been investigated as a function of the Reynolds number and geometric parameters. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] | ||||||||||