Effect of Operating Parameters

In general, small/light particles can enhance heat transfer. The cluster formation in small/light particle systems contributes to the enhancement of hpc. Also the gas film resistance can be reduced by fluidizing with small particles [Wu et al., 1987]. When the temperature is lower than 400°C, the effect of bed temperature on the heat transfer coefficient is due to the change of gas properties, while hr is negligible. At higher temperatures, h increases with temperature, mainly because of the sharp increase of radiative heat transfer. 

Measurements of heat transfer in circulating fluidized beds require use of very small heat transfer probes, in order to reduce the interference to the flow field. The dimensions of the heat transfer surface may significantly affect the heat transfer coefficient at any radial position in the riser. All the treatment of circulating fluidized bed heat transfer described is based on a small dimension for the heat transfer surface. The heat transfer coefficient decreases asymptotically with an increase in the vertical dimension of the heat transfer surface [Bi et al., 1990]. It can be stated that the large dimensions of the heat transfer surface 

12 / Heat and Mass Transfer Phenomena in Fluidization Systems 

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Chapter 10 deals with laminar flow in heated capillaries where the meniscus position and the liquid velocity at the inlet are unknown in advance. The approach to calculate the general parameters of such flow is considered in detail. A brief discussion of the effect of operating parameters on the rate of vaporization, the position of the meniscus, and the regimes of flow, is also presented. 

Moholkar et al. [11] studied the effect of operating parameters, viz. recovery pressure and time of recovery in the case of hydrodynamic cavitation reactors and the frequency and intensity of irradiation in the case of acoustic cavitation reactors, on the cavity behavior. From their study, it can be seen that the increase in the frequency of irradiation and reduction in the time of the pressure recovery result in an increment in the lifetime of the cavity, whereas amplitude of cavity oscillations increases with an increase in the intensity of ultrasonic irradiation and the recovery pressure and the rate of pressure recovery. Thus, it can be said that the intensity of ultrasound in the case of acoustic cavitation and the recovery pressure in the case of hydrodynamic cavitation are analogous to each other. Similarly, the frequency of the ultrasound and the time or rate of pressure recovery, are analogous to each other. Thus, it is clear that hydrodynamic cavitation can also be used for carrying out so called sonochemical transformations and the desired/sufficient cavitation intensities can be obtained using proper geometric and operating conditions. 

Sobana, N. and Swaminafhan, M. (2007) The effect of operational parameters on the photocatalytic degradation of Acid Red 18 by ZnO. Separation and Purification Technology, 56, 101-107. 

Table 4. Summary of the Effects of Operating Parameters on W etting in the Granulation Process...

The effect of operating parameters cannot be predicted reliably, although a substantial amount of work has been published on the operation of spouted beds(84,85,86). 

Suzuki, A., Nakamura, T., Yokoyama, S. 1990. Effect of operating parameters on thermochemical liquefaction of sewage sludge. J Chem Eng Jpn 23 6-11. 

Muruganandham, M Swaminathan M. Ti02-UV photoeatalytie oxidation of Reactive Yellow 14 Effect of operational parameters. Journal of Hazardous Materials, 2006 in press. 

Daneshvar, N Salari, D Khataee AR. Photocatalytic degradation of azo dye acid red 14 in water investigation of the effect of operational parameters. Journal of Photochemistry and Photobiology A Chemistry, 2003 157, 111-116. 

This chapter will describe the operation of an ICP and explain why certain physical parameters contribute to sensitivity and freedom from interferences. Commercially available, modular assembled (ICP-AES) systems will be discussed with respect to the general configurations which they employ. The origin of spectral interferences and their accomodation will be explained. The effect of operating parameters and data-processing requirements will be discussed. General as well as environmental applications will be enumerated and specific examples given. 

Figure 24-16 shows effects of operating parameters in split and splitless injections. Experiment A is a standard split injection with brisk flow through the split vent in Figure 24-15. The column was kept at 75"C. The injection liner was purged rapidly by carrier gas, and peaks are quite sharp. Experiment B shows the same sample injected in the same way, except the split vent was closed. Then the injection liner was purged slowly, and sample was applied to the column over a long time. Peaks are broad, and they tail badly because fresh carrier gas continuously mixes with vapor in the injector, making it more and more dilute but never completely flushing the sample from the injector. Peak areas in B are much greater than those in A because the entire sample reaches the column in B, whereas only a small fraction of sample reaches the column in A.

Equation (9.11) identifies the three factors that determine the performance of a pervaporation system. The first factor, pevAp, is the vapor-liquid equilibrium, determined mainly by the feed liquid composition and temperature the second is the membrane selectivity, G-men, an intrinsic permeability property of the membrane material and the third includes the feed and permeate vapor pressures, reflecting the effect of operating parameters on membrane performance. This equation is, in fact, the pervaporation equivalent of Equation (8.19) that describes gas separation in Chapter 8. 

Abstract In this paper, we discuss the results of a preliminary systematic process simulation study the effect of operating parameters on the product distribution and conversion efficiency of hydrocarbon fuels in a reforming reactor. The ASPEN One HYSYS-2004 simulation software has been utilized for the simulations and calculations of the fuel-processing reactions. It is desired to produce hydrogen rich reformed gas with as low as possible carbon monoxide (CO) formation, which requires different combinations of reformer, steam to carbon and oxygen to carbon ratios. Fuel properties only slightly affect the general trends. 

Table 5.6 Effects of Operating Parameters on Chiral Separations3...

The second part of this chapter will deal with the performance of mediated oxidation with persulfate and the BDD anode using the single-cell treatment method. Experimental tests at different temperatures and concentrations of organic pollutants, with and without the mediated oxidation, will be done to detect the effect of operating parameters on the overall efficiency of the electrochemical treatment. 

Cheng, H., Scott, K. and Christensen, P. A. (2003b) Electrochemical hydrodechlorination of chlorinated phenols in aqueous solutions - Part II. Effect of operating parameters. J. Electrochem. Soc. 150, D25-D29. 

This method of dealumination seems therefore ideal for preparing samples differing only by their Si/Al ratio. Actually, it is not the case as was shown by several teams47 49 which have determined the effect of operating parameters reaction time, temperature, pH, (NH SiFe/zeolite ratio, on the characteristics of dealuminated HY samples. 

CDP12-Pb Calculate the effect of operating parameters on conversion for the reaction limited and transport limited operation. 

Kuo, K.P. and Cheryan, M., Ultrafiltration of acid whey in spiral-wound unit Effect of operating parameters on membrane fouling, J. 

Thermoporometry measurements allow to evidence the effects of operating parameters of the preparation process on the texture of hydrogels of silica and silica-alumina. As the aim... 

As discussed in Chapter 3, with LES, the smallest scale to be resolved is chosen to lie in the inertial sub-range of the energy spectrum, which means the so-called sub-grid scale (SGS) wave numbers are not resolved. As LES can capture transient large-scale flow structures, it has the potential to accurately predict time-dependent macromixing phenomena in the reactors. However, unlike DNS, a SGS model representing interaction of turbulence and chemical reactions will be required in order to predict the effect of operating parameters on say product yields in chemical reactor simulations. These SGS models attempt to represent an inherent loss of SGS information, such as the rate of molecular diffusion, in an LES framework. Use of such SGS models makes the LES approach much less computationally intensive than the DNS approach. DNS... 

Nikbakht, R., Sadrzadeh, M., and Mohammadi, T. 2007. Effect of operating parameters on concentration of citric acid using electrodialysis. Journal of Food Engineering 83 596-604. 

Kramer, P.W. Yasuda, H. Effect of operational parameters on the air separation properties of composite hollow fiber membranes prepared by plasma polymerization of perfluorodimethyl cyclobutane. J. Appl. Polym. Sci. Appl. Polym. Symp. 1988, 42, 381. 

Table 5 summarizes the effect of operating parameters (particle size, solution concentration, separation factor, stirring rate, resin exchange capacity, and temperature) on ion exchange kinetics described by these different models in batch reactors. 

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