摘要:

AbstractThis article describes a novel approach to the systematic synthesis of heat exchanger networks. For a given synthesis problem, this approach leads to a complete listing of all solutions which exist, using a prescribed degree of energy recovery, the minimum number of exchangers, heaters and coolers, and no split streams. The approach is combinatorial, with a variety of thermodynamic criteria used to minimize the problem size by preventing infeasible solutions being generated. Two examples (5SPI and 6SPI) are discussed to illustrate complete solution by hand.

ISSN:0001-1541    

DOI:10.1002/aic.690260102

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractTracer gas dispersion was measured for laminar flow through three different tube constrictions, at orifice Reynolds numbers between 10 and 5000 and Schmidt numbers of 0.213 and 0.769. Each constriction generates a confined jet which significantly enhances axial dispersion at intermediate Reynolds numbers ranging from 100 to 1000.

ISSN:0001-1541    

DOI:10.1002/aic.690260103

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractA mathematical model is developed to describe non‐isothermal sorption kinetics and used to interpret experimental uptake curves for CO2in 4A zeolite and for CO2and in C5H12in 5A zeolite. The model assumes that the dominant mass transfer resistance is intracrystalline diffusion while the major resistance to heat transfer is the external heat transfer between the adsorbent sample and the surroundings. It gives a good representation of the kinetic behavior over a wide range of conditions. Both the extreme cases of isothermal diffusion and complete heat transfer control are demonstrated experimentally. Intermediate situations, in which the uptake rate is controlled by the combined effects of diffusion and heat transfer, are demonstrated as well. The parameters derived from the model are consistent, reproducible, and agree well witha prioriestimates. The model provides a useful theoretical basis for the analysis of rapid sorption processes for which the non‐isothermal approximation is inva

ISSN:0001-1541    

DOI:10.1002/aic.690260104

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractFor moving‐bed solids flow in an inclined pipe leading into a fluidized bed, the pressure drop across the pipe is a retarding force while the gas leakage rate alters the flow properties of the solids. The pressure drop has been related to the pipe exit pressure, which, in turn, can be calculated by integrating the solids bulk density over the bed depth. A correlation for the rate of gas leakage in terms of the geometric features and operating conditions of the system is developed. The correlation agrees with experimental data to within ± 25%. Part II of this paper will deal with solids fl

ISSN:0001-1541    

DOI:10.1002/aic.690260105

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractThe purpose of part II of this paper is to theoretically analyze and experimentally examine moving‐bed solids flow in an inclined pipe connecting a fluidized bed and a solids storage vessel. The macroscopic momentum balance equation is simplified and applied to the present system. A friction factor correlation is developed. Based on the flow curves constructed, we found that the power law model is suitable for describing moving‐bed solids f

ISSN:0001-1541    

DOI:10.1002/aic.690260106

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractBased on recent work by Powell, a new optimization algorithm is presented. It merges the Newton‐Raphson method and quadratic programming. A unique feature is that one does not converge the equality and tight inequality constraints for each step taken by the optimization algorithm. The article show how to perform the necessary calculations efficiently for very large problems which require the use of mass memory. Experience with the algorithm on small problems indicates it converges exceptionally quickly to the optimal answer, often in as few iterations (5 to 15) as are needed to perform a single simulation with no optimization using more conventional approache

ISSN:0001-1541    

DOI:10.1002/aic.690260107

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractDiffusion in concentrated, non‐ideal liquid solutions may take place not only through motion of single molecules but also through movement of groups of molecules, or “clusters.” Analyzing this cluster diffusion leads to predictions that the diffusion coefficient can vary with the square root of the usual activity corrections to diffusion. These predictions seem consistent with experiments, particularly in highly non‐ideal so

ISSN:0001-1541    

DOI:10.1002/aic.690260108

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractCorrelations of the collision frequency and the coalescence frequency of an agitated dispersion are combined with models relating drop sizes and hold‐up to agitator speed, to predict the ambivalence range and phase inversion composition of liquid‐liquid dispersions. Our model was tested by comparing predicted and experimental phase invesrion compositions of the system toluene‐water ad carbontetrachloride‐water. In addition, the predicted results have been compared ith published results for the system kerosene‐water, and in all cases, agreemet between predicted and experimental resutls are

ISSN:0001-1541    

DOI:10.1002/aic.690260109

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractIn this article, we analyze the performance of a dluted catalyst pellet consisting of inert and active particles under diffusion influenced conditions and pore‐mouth poisoning. First, we establish the requirements for validty of the analytical soltuions of the diluted pellet equations. Secondly, we show that, under pore‐mouth poisoning conditions, a diluted pellet can display considerably longer lifetimes than a uniformly impregnated catalyst. Conversely, for the same lifetime, use of a diluted pellet can result in savings of the catalytic agent. These advantages are not offset by difficulties in catalyst manufacture, as is the case for previous desi

ISSN:0001-1541    

DOI:10.1002/aic.690260110

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY

摘要:

AbstractA reactor of fiour crossflow nomolithic blocks is used to approximate a cocurrent and a countercurrent reactor‐heat excanger. Essentailly isothermal reaction pass profiles are produced by flowing the coolant and reactant streams cocurrent to each other according to the criteria set down in Part I of this paper. A multiplicy of steady states is shown to exist for the autothermal countercurrent mode, but not for the autothermal cocurrent mode, under identical condition

ISSN:0001-1541    

DOI:10.1002/aic.690260111

出版商:American Institute of Chemical Engineers    

年代:1980

数据来源: WILEY