摘要:

AbstractExperimental investigations of headlosses and particle velocity distributions have been undertaken for water slurries of polystyrene particles of diameterd50= 0.3 and 1.4 mm. At concentrations greater than 40–45% by volume, nearly linear headloss vs. velocity relationships were obtained. These suggested laminar flow but the particle velocity measurements showed the flow to be turbulent.The results have been interpreted with an approximate theory based upon lubrication mechanics. The investigation illustrates the limitations of slurry viscometry in predicting pipeline behaviour for slurries of particles of this siz

ISSN:0008-4034    

DOI:10.1002/cjce.5450630601

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

年代:1985

数据来源: WILEY

摘要:

AbstractRheological properties of black coal‐KC220 oil suspensions have been investigated using a Contraves rheometer over a temperature and coal volume fraction range of 18–200°C and 0.247‐0.385, respectively. The suspensions behaved as Newtonian fluids. Variation of viscosity with temperature does not follow any regular trend and peak viscosity values occur in the temperature range of 80–140°C for dry coal and 70–130°C for moist coal, depending upon the concentrations of coal in the suspension. Freshly prepared suspensions of moist coal exhibit viscosity peaks at a temperature lower than that of the corresponding suspension with dry coal. However, when aged, the suspensions of moist coal exhibit very small peak viscosity and follow an Arrhenius type behavior. For both dry and moist coal, the maximum volume fraction, ϕm, continues to decrease with an increase i

ISSN:0008-4034    

DOI:10.1002/cjce.5450630602

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

年代:1985

数据来源: WILEY

摘要:

AbstractMiscible displacement experiments were carried out to evaluate the potential of solvents in enlarging fractures between wells to allow for larger volumes of steam to be injected during in situ recovery operations in the Athabasca oil sands deposit. The solvents tested included carbon disulfide, toluene and a series of refinery streams and diesel oils. Since incomplete miscibility between bitumen and some solvents caused asphaltenes to precipitate, solvents were ranked in terms of bitumen compatibility.Solvents such as diesel DP‐40 and diesel DC‐40, which are intermediate in terms of solubilizing bitumen, were the most efficient in developing zones of low bitumen saturation around an initial fracture and at the same time not extracting bitumen from other regions of the bed. The effects of flow rate and cell orientation on solvent efficiency and permeability are also described. Solvent losses corresponded to about the residual saturation of oil after waterflood

ISSN:0008-4034    

DOI:10.1002/cjce.5450630603

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

年代:1985

数据来源: WILEY

摘要:

AbstractAs the gas flow rate is increased through a bed of particles lying on a multi‐orifice gas distributor, several gas pressure maxima arise in the plenum chamber which correspond to the occurrence of fluidization in different sections of the bed. The gas pressure at the distributor orifices may considerably exceed the quantiy ρsg(1 − ϵ0)H. A formula has been derived for the complete‐fluidization index at which all caps come in

ISSN:0008-4034    

DOI:10.1002/cjce.5450630604

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

年代:1985

数据来源: WILEY

摘要:

AbstractA model is described to simulate a non‐woven unneedled fibre filter which describes the basic random structure of these materials. Good agreement is obtained between the observed structure of non‐woven filter fabrics and the predictions of the model. Data on the pore structure, pore area, perimeter and hydraulic radius can be predicted from the model.This description of a non‐woven filter is used in a stochastic trajectory model to calculate particle filtration. The analysis applies to filtration of dilute suspensions in the regime where particle screening is the predominant mechanism of filtration. The model predicts that the penetration into the filter decays exponentially with depth in the direction of flow. The interaction between the particle distribution on filter media (pore distribution) is taken fully into account in the analysis. The computational method allows the effect of particle size distribution on filtration efficiency, pore blockage and pore binding to be eval

ISSN:0008-4034    

DOI:10.1002/cjce.5450630605

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

年代:1985

数据来源: WILEY

摘要:

AbstractAnalytical models were developed to predict the performance of a spray scrubber for separation of tars from gasifier off‐gas streams. The models included heat transfer, mass transfer, condensation, nucleation, temperature and flow fields, and various phoretic phenomena involved in droplet‐particle and droplet‐vapor interaction and collection. The models indicate that for the tar particulates, both Brownian diffusion and inertial impaction, rather than diffusiophoresis and thermophoresis, are the more important phoretic forces causing the collection. For the limiting case of all tars being present only as vapor, the efficiency of their removal by condensation on water spray droplets could be extremely high.Scrubbing experiments were carried out on the hot gas/tar stream evolved from the simulated devolatilization section of a laboratory fixed bed gasifier. The combined overall collection efficiency for a mixed particulates and vapor stream compares satisfactorily with the model predic

ISSN:0008-4034    

DOI:10.1002/cjce.5450630606

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

年代:1985

数据来源: WILEY

摘要:

AbstractMass transfer across gas and liquid boundary layers into the core of drops with liquid phase first order chemical reaction has been analyzed for spherical drops in the Reynolds number range of 50

ISSN:0008-4034    

DOI:10.1002/cjce.5450630607

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe ethanol fermentation has been studied as a model system for end product inhibition and extractive fermentation. Examination has been done on the basis of theoretical considerations, as well as experimental evaluation. For the latter case, a database has been developed in order to screen more than 1,500 solvents for their suitability as extractants in the system solvent‐ethanol‐water. Based on this screening, 62 solvents have been tested with yeast cultures to determine experimentally such important parameters as biocompatibility, distribution coefficients and phase stability. Fifteen of these solvents have proven to be completely biocompatible, while 26 were completely toxic, the remaining solvents showing different degrees of inhibition.In this paper, the theoretical and experimental procedures involved in the systematic screening of extractive fermentation solvents will be outlined. Also, some heuristic criteria will be presented that allow for an evaluation of solvent biocompatibilitya pri

ISSN:0008-4034    

DOI:10.1002/cjce.5450630608

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

年代:1985

数据来源: WILEY

摘要:

AbstractCoal liquefaction kinetic rate constants play an important role in the design and operation of liquefaction reactors. The objectives of this work are to present a comparative review of the measurement techniques which have appeared in the recent literature, and to analyse briefly some of the kinetic models used in the measurements of the rate constants. A mathematical technique to analyse multicomponent‐multireaction kinetic schemes using the data obtained from autoclave (closed) and continuous stirred tank reactors (CSTR, open) is discusse

ISSN:0008-4034    

DOI:10.1002/cjce.5450630609

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe gasification of a metallurgical coke with CO2/N2mixtures in a 0.1 m diameter fluidised bed has been studied over the temperature range 810–1050°C. The rate of gasification was found to be essentially kinetically controlled, with negligible influence of fluidisation parameters below 1000°C.A number of flow models were assessed. The plug flow model was found to be the simplest model which could predict the experimental results, giving similar results to the more complex two‐phase flow model of Davidson and Harrison (1963).For the range of conditions studied, the simplenth order reaction model was used to determine a best value of the reaction order of 0.8. For this combination of flow and reaction models, an activation energy of 197 kJ/mol was deduced from the experiments, in agreement with packed bed results and literature data.Very simple models can be used to predict the experimental results within the range st

ISSN:0008-4034    

DOI:10.1002/cjce.5450630610

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

年代:1985

数据来源: WILEY