摘要:

AbstractCoal‐oil mixtures which have the potential to stretch oil usages have been analyzed as to their sedimentation behavior by applying a modification of the continuity wave theory as developed by Kynch. Three coal‐oil systems have been studied and have been shown to follow the pseudo continuity wave theory by assigning a degree of agglomeration to the coal particles. With the presence of surfactants, the sedimentation of the mixtures could be similarly analyzed. The general effects of particle size of the coal and temperature of the system have been considered and presented as guidelines for des

ISSN:0008-4034    

DOI:10.1002/cjce.5450590402

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe primitive Navier‐Stokes equations were solved to predict the flow field induced by a partially confined swirling laminar jet impinging normally on a flat surface. A study is made of the influence of the jet Reynolds number, nozzle‐to‐plate spacing, axial and swirl velocity profiles at nozzle exit plane, size of the confining and impingement plate and uniform suction applied at the plate. An interesting feature of the flow configuration is the predicted development of a recirculation bubble in the stagnation region which influences the heat and mass transfer characteristics. Axial and swirl velocity profiles at entry have dominant influence on the development of the flow

ISSN:0008-4034    

DOI:10.1002/cjce.5450590403

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

年代:1981

数据来源: WILEY

摘要:

AbstractFluctuations in the output voltage from a conventional magnetic flux flowmeter have been shown to depend upon mean velocity and slurry concentration. Since reliable values of mean velocity can be obtained from time‐average voltages, the fluctuations could be used to sense slurry concentrationThe relationship between the fluctuations and slurry concentration depends on particle and fluid properties so that calibration would be required. However with further progress in understanding of vertical slurry flows, the relationship may be predictabl

ISSN:0008-4034    

DOI:10.1002/cjce.5450590404

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

年代:1981

数据来源: WILEY

摘要:

AbstractAccording to the Reynolds' equation the time taken for a thin film to reach a critical thickness at which rupture occurs is a function of the film area and applied force. It follows that the coalescence time of a liquid drop is greatly affected by its geometrical configuration. If the drop is unconstrained the coalescence time increases when a vertical force is applied to the drop, but if the drop is constrained by the presence of surrounding drops its coalescence time decreases as the applied force increases. This explains why the rate of coalescence at the disengaging interface of a close‐packed dispersion increases with the dispersion height. The coalescence time for a planar film is usually less than for the spherical film formed between a drop and its homophase which explains why near‐horizontal surfaces inserted into close‐packed dispersion increase the rate of coalescence. The coalescence time of a drop in a close‐packed dispersion decreases as it approaches the disengaging interface. This means that the volume rate of coalescence at the interface may equal the disperse phase throughout without the necessity for interdrop coalescence. When the applied pressure is much greater than the van der Waals pressure, as in a close‐packed dispersion, the critical film thickness is itself a function of the film area and applied force, but this has little effect on the above conclusions. When the applied pressure is much less than the van der Waals pressure, as in a loose‐packed dispersion, the critical film thickness is only a function of the film area and the affect of the applied force on the coalescence time is the

ISSN:0008-4034    

DOI:10.1002/cjce.5450590405

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

年代:1981

数据来源: WILEY

摘要:

AbstractMechanical degradation of a semi‐dilute solution of non‐hydrolyzed polyacrylamide was studied under laminar flow conditions through fine capillary systems. Using a multi‐pass device and capillary tubes of the same diameter and of various lengths we have shown that mechanical degradation (i) occurs at a critical value of the wall shear rate, chosen as a reference deformation rate, which is slightly higher than that of the appearance of high pressure losses in the entrance region of the capillary tube; (ii) is independent of the capillary tube length; (iii) increases with the number of passes N up to a maximum value for a limiting number of passes Nlimwhich is a decreasing function of deformation rates but does not depend on capillary length.The amount of degradation is expressed in terms of loss of viscous dissipation in shear and transient elongational flow. This last point is determined by studying the total end pressure loss through the capillary tube as a function of the pass number. The high pressure loss is related to viscous dissipation on macromolecules stretched by rapid converging flow. A comparison between a fresh and a fully degraded solution indicates that the degradation affects shear viscosity much less than viscous dissipation in rapid converging flow which is related to the properties of extended macromolecules. Both experimental results and theoretical interpretation suggest that, in our capillary system, the mechanical degradation occurs in the entrance region of the capillary where macromolecules are stretched and consequently submitted to extensional forces which can overcome the C–C bonds s

ISSN:0008-4034    

DOI:10.1002/cjce.5450590406

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

年代:1981

数据来源: WILEY

摘要:

AbstractOne concept for the in‐situ production of oil from the tar sands involves the continuous injection of steam into a growing steam‐saturated volume or steam chamber. Steam flow to the boundary of the chamber, condenses and gives up its heat to the surrounding oil sands. The condensate and heated oil flow by gravity to a production well located at the bottom of a chamber and are removed continuously. The well may consist of a horizontal slotted pipe. This paper describes the theory of operation of such a process and an equation is derived which predicts the rate of drain

ISSN:0008-4034    

DOI:10.1002/cjce.5450590407

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

年代:1981

数据来源: WILEY

摘要:

AbstractMeasurements have been made of the effective thermal conductivity of some samples of Athabasca oil sands using a steady state method over the temperature range 20°C – 120°C. The bitumen content of the samples was altered from its natural value by mixing with additional sand and the resulting values of the thermal conductivity were found to increase with increasing the oil content. Moreover, the effective thermal conductivity values were found to decrease with increasing temperat

ISSN:0008-4034    

DOI:10.1002/cjce.5450590408

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe diffusion equation for infinite cylindrical sources has been solved for the boundary conditions appropriate to timed‐release fertilizer pellets. The solution was tested against experimental results of the distortion of the image of a grind illuminated by laser light and recorded on video tape. The optical theory was examined for validity using Fermat's Principle. A computer program was developed to predict concentration as a function of time and distance with sufficient flexibility to allow for multiple sources and any other variation which can be accounted for by change of diffusion coefficien

ISSN:0008-4034    

DOI:10.1002/cjce.5450590409

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe kinetics of the reaction between dissolved oxygen and sodium dithionite in alkaline aqueous solution was investigated in a stirred cell. For dithionite concentrations below 0.08 kmol/m3and sodium hydroxide concentrations from 0.044 to 0.27 kmol/m3, the results show the reaction to be first order in dithionite and zero order in oxygen. The Arrhenius activation energy was determined to be 76.2 MJ/kmol in the temperature range 15 to 34°C. Addition of other electrolytes (sodium sulphate or potassium chloride) had no effect on the kinetics

ISSN:0008-4034    

DOI:10.1002/cjce.5450590410

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

年代:1981

数据来源: WILEY

摘要:

AbstractResin phase mass transfer in a weak acid ion‐exchanger was analyzed based on a shrinking core model. It was assumed that H‐form core and metallic ion‐form shell appear in sorption of metallic ion, while metallic ion‐form core and H‐form shell appear in regeneration of metallic ion‐type resin. At the moving boundary, instantaneous irreversible reaction occurs, namely, neutralization reaction in the sorption and the protonation reaction in the regeneration. The Nernst‐Planck equation was applied to the fluxes of ions diffusing through the shell and the analytical solutions of sorption and regeneration rates were derived by assuming a pseudo‐steady state diffusion. Those solutions agreed fairly well with the experimental results in R‐H‐NaOH system (sorption) and in R‐Na‐HCl, R‐Cu‐HCl and R‐C

ISSN:0008-4034    

DOI:10.1002/cjce.5450590411

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

年代:1981

数据来源: WILEY