摘要:

AbstractA design approach based on a phase diagram of inlet temperatures is proposed for the countercurrent reactor/heat exchanger for highly exothermic reactions with inherent parametric sensitivities. The phase diagram shows the region of safe operation on a plane of feed and coolant inlet temperatures, free from runaway conditions. The boundaries surrounding the safe operation region are defined by design parameters. Simple procedures applicable to arbitrary expressions of global rate are developed for the phase diagram. The multi‐pronged design problem of selecting the design parameters and operating conditions for the maximum possible conversion within the constraints due to the parametric sensitivities is condensed into the represented by a phase diagram and an analysis on the phase plane. A design alternative which eliminates the necessity of the preheater for highly exothermic reactions is discussed and the advantages are quantitatively illustrated to assert that this design should be seriously considered as a viable alternativ

ISSN:0001-1541    

DOI:10.1002/aic.690290112

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractA principal mechanism for rapid mixing and fragmentation in vapor explosions, such as have occurred in the LNG, aluminum, steel and paper industries, is thought to be nonlinear Taylor instability. An analysis, based on a generalized coordinate method developed by Dienes for a fluid with an arbitrary constitutive law, is here extended to a two‐fluid model, with or without mass transfer between the fluids. Numerical results indicate that in a steam‐water system entrainment starts in times of order 10−4s at 100 G acceleration normal to the interface. For gas‐liquid systems the presence of the second fluid changes the instability growth only slightly. Condensation of steam, even when limited only by the kinetic theory interfacial resistance, also has minor effects on the growth rate. However, condensation on the entrained drops will have a major effect on the accel

ISSN:0001-1541    

DOI:10.1002/aic.690290113

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractThe mechanics of particle motion in a fluidized bed were studied by focusing on the microscopic behavior of the particles. The local displacements of nylon particles fluidized by liquid were measured by the micro‐capacitance method, and the resultant time series was analyzed by determining its auto‐correlation function and the corresponding power spectrum. This has given rise to a stochastic or statistical model of particle displacements in the fluidized bed. This model visualizes the particle motion in a fluidized bed to consist of the random movement, generating irregular signals, and the linear movement, generating wave‐like si

ISSN:0001-1541    

DOI:10.1002/aic.690290114

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractAn empirical correlation for the third virial coefficient of nonpolar gases is developed. The correlation requires a knowledge of the critical temperature, critical pressure and acentric factor of the compounds for the prediction of third virial coefficients in the absence of experimental data. The use of the correlation for mixtures of nonpolar gases, including quantum gases, requires one binary parameter for each binary interaction. Predictions are in good agreement with reported experimental data and with the values obtained with existing correlations.

ISSN:0001-1541    

DOI:10.1002/aic.690290115

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractThe main task of the θ convergence promoter is to afford a better estimate of liquid and vapor molar fractions in each tray of the column.The assumptions implied by the promoter prove to be reliable for conventional columns, while they may cause numerical instability when dealing with nonconventional configurations. In these cases, corrected molar fractions may be computed only after making a supplementary assumption, which in principle is not unique. So, the paper presents a new methodology which gives rather satisfactory results

ISSN:0001-1541    

DOI:10.1002/aic.690290116

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractA model for the liquid‐phase residence time in a trickle‐flow reactor has been derived and experimentally verified using a tracer input. The model, termed the Ideal Plug Flow Stagnancy Model, postulates that the prime liquid‐phase dispersive mechanism in such reactors is the interchange between the dynamic and stagnant regions. Unlike previous models, however, it does not require the assumption of perfect mixing in the stagnant zones. While the results of the study confirm that the mixing is incomplete, they show clearly that back mixing rather than molecular diffusion is the dominant exchange mech

ISSN:0001-1541    

DOI:10.1002/aic.690290117

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractThe dynamic pulse‐response technique was used to measure effective diffusivities under nonreacting conditions in two, unsulfided, extrudate‐type, hydrodesulfurization catalyst pellets of different porosities. Pore‐volume distribution data showed a bidisperse pore structure with a broad pore‐size range (100 μm to 3 nm).The main purpose of the study was to evaluate various methods for calculating the tortuosity factor, τ. For this particular catalyst, the most constant and unreasonable values of τ were obtained by supposing that diffusion occurred in all the pore volume (micro and macropores) and by summing the combined Knudsen and bulk contributions over each increment of p

ISSN:0001-1541    

DOI:10.1002/aic.690290118

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractA new apparatus to measure partition coefficientsK s∞at infinite dilution up to 200 105Pa and 423 K is described. Measurements of the systems: (1) methane‐ethane‐n‐decane and methane‐propane‐n‐decane at 294.25 K; and (2) methane‐n‐butane‐n‐decane at 344.25 K illustrate the reproducibility and good agreement with literature data. In addition, new data were obtained for the system methane‐n‐pentane‐n‐dec

ISSN:0001-1541    

DOI:10.1002/aic.690290119

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractLiquid membranes containing macrocyclic polyethers can be used to electrorefine metals. This purification depends on the selective reaction of the polyether and the metal cation to produce a charged product. The amount of this product is found to be proportional to the square root of the amount of polyester present. Results for silver and copper purification illustrate the ideas involved.

ISSN:0001-1541    

DOI:10.1002/aic.690290120

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY

摘要:

AbstractTheoretical investigation shows that a transition in the solid state from form I to form II affects the solubility of a solid in a liquid. Experimental results for the solubility of phenanthrene in pyridine, which has a lambda‐point transition between 331 and 361 K, conform generally to the theoretical prediction

ISSN:0001-1541    

DOI:10.1002/aic.690290121

出版商:American Institute of Chemical Engineers    

年代:1983

数据来源: WILEY