摘要:

AbstractThe collapsing liquid column phenomenon has been experimentally and theoretically studied. The experimental data demonstrated the development and travel of a shock wave. Point velocities within the flow regime were measured using a hot film probe. The numerical simulation was performed using a finite difference code similar to the Marker and Cell technique. The results were in good agreement with the experimental data. The numerical technique therefore promises to be a valuable aid in studying highly convective, incompressible flows.

ISSN:0008-4034    

DOI:10.1002/cjce.5450580102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractAerosol deposition from a flowing stream onto a single spherical collector with gravitational force acting transverse to the direction of flow was studied. The effects of inertial impaction, gravitation, interception and electrostatic forces were examined. In contrast to the case where gravitational force acts along the direction of the flow, the particle trajectories are not axisymmetrical and the trajectory equations are three‐dimensional. The formulation and numerical solutions of such equations represent the main task of this wor

ISSN:0008-4034    

DOI:10.1002/cjce.5450580103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractBased on the velocity profiles around clean and relatively contaminated gas bubbles, the tangential and normal stress, pressure distribution at the surface around the gas bubbles, and finally the viscous, form and total drag coefficient of the gas bubbles were calculated and compared with experimental values for dilute aqueous solutions of alcohols. The theory verifies the experimental observation that the total drag coefficient of single gas bubbbles increases with the contamination factor. The effect of the void fraction of the gas bubble swarm on the total drag coefficient was examined by the use of a void function. Most of the void functions for the relatively contaminated gas bubble swarms were between the values of potential flow and that of solid spheres.

ISSN:0008-4034    

DOI:10.1002/cjce.5450580104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractDead volume cannot be avoided in measurements of kinetic and transport parameters using pulse gas chromatography. A criterion is derived for the bed volume necessary to make these dead volume effects negligible. Application of the criterion and assumptions made in its development are discussed.

ISSN:0008-4034    

DOI:10.1002/cjce.5450580105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA gas chromatographic study of binary diffusion of gas pairs: H2‐Air, H2‐Ar, H2‐O2and H2‐N2was conducted at 30°C in a gas chromatograph GCHF‐18 (East Germany) using Gow Mac filament as T.C. detector. Air, argon, oxygen and nitrogen were injected in flowing stream of hydrogen in a stainless steel halical column 4 mm in inside diameter and 3 meters in length. The arrested flow method was used for measuring the variance. The values of diffusion coefficients thus obtained were within −2.47 to +2.43% of the values by Fuller's correlation, 0.12 to 3.38% of the values by correlation of Chapman‐Enskog and −29.99 to −32.94% of the values by Gilli

ISSN:0008-4034    

DOI:10.1002/cjce.5450580106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe performance of a bioreactor composed of two chemostats in series can be affected significantly by the split of feed into two, one for each chemostat, for reactions following Monod kinetics. Under certain operating conditions, split of feed can be greatly beneficial to the reactor performance.Optimization of performance is discussed; a general criterion is presented, applicable to either the maximization of overall conversion for a given total residence time or the minimization of total residence time for a given overall conversion. The maximization of overall conversion has also been studied with respect to the feed‐split ratio. The dimensionless Michaelis‐Menten constant is a very important parameter in the selection of optimal operating conditi

ISSN:0008-4034    

DOI:10.1002/cjce.5450580107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractAn interesting feature of commercial continuous emulsion polymerization reactors is the important phenomenon of sustained oscillations. Laboratory investigations of emulsion polymerization in a continuous stirred tank reactor (CSTR) have shown that the conversion, number of polymer particles and other related properties often oscillate widely with time. These oscillations can lead to emulsifier levels too small to adequately cover polymer particles resulting in excessive agglomeration and reactor fouling. Herein is reported an extensive experimental study of vinyl acetate emulsion polymerization in a CSTR. The effects of initiator and emulsifier concentrations, mean residence time and rate of agitation on the production rate and size distribution of polyvinyl acetate latices were investigated. Domains of reactor operation which give rise to sustained oscillations and massive agglomeration of the latex are mapped which give rise to sustained oscillations and massive agglomeration of the latex are mapped out. The effect of different start‐up policies on reactor transients were also investigate

ISSN:0008-4034    

DOI:10.1002/cjce.5450580108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractConversion data obtained over a wide range of operation of a continuous latex reactor for vinyl acetate polymerization were used to estimate the unknown kinetic parameters of a transient CSTR reactor model. Conversion‐time histories were adequately fitted by models of two levels of sophistication: a comprehensive model which solves for the age distribution function of polymer particles, and a simplified model that neglects the effect of particle size distribution for the case of continuous particle nucleation. These models were then used for simulation and control studies in an attempt to devise a practical control strategy(11). The existence of sustained oscillations was investigated by examining the behavior of the state variables in the phase‐pl

ISSN:0008-4034    

DOI:10.1002/cjce.5450580109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractHerein is reported an experimental evaluation of turbidity‐spectra and of liquid exclusion chromatography (LEC) for the online and offline monitoring of polymer particle size during the continuous emulsion polymerization of vinyl acetate. It is shown that these analytical techniques satisfactorily follow the change of particle size for reactor operation under conditions of sustained oscillation

ISSN:0008-4034    

DOI:10.1002/cjce.5450580110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe oxidation of low concentrations of hydrogen sulfide with air over activated carbon was studied over the temperature range 24‐200°C using both fixed and fluid bed reactors. The predominant reaction, H2S + ½ Oa→ H2O + S, was found to have an order of 0.5 with respect of H2S concentration. Activity of the catalyst decreased as the amount of sulfur deposited on it increased. Indirect evidence suggests that adsorption of water by the carbon also decreases its activity as a catalyst at lower temperatures. Values of the activation energy and the frequency factor were determined for various sulfur loadings using the fixed bed reaction system. Regeneration of the carbon loaded with sulfur was studied at temperatures between 150 and 500°C using steam as a carrier gas. Bright yellow sulfur was recovered. The regenerated carbon was shown to have its original ac

ISSN:0008-4034    

DOI:10.1002/cjce.5450580111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY