摘要:

AbstractA horizontal pulsed solvent extraction column (HPC) has great potential in replacing vertical pulsed columns (VPC) in the separation of heavy elements in the nuclear industry. Published work examining the performance of the HPC suggests that the mass transfer efficiency for this column is comparable to the VPC, but information on the hydrodynamic characteristics of the HPC is sparse. This paper describes the flow characteristics of the HPC and presents experimental results and correlations for flooding conditions and holdup of the dispersed phase. Correlations obtained for the HPC for these hydrodynamic parameters are compared to published results for the VPC.

ISSN:0008-4034    

DOI:10.1002/cjce.5450700302

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

年代:1992

数据来源: WILEY

摘要:

AbstractOn a étudié l'ascension des gouttes dans de l'eau contaminée avec deux agents tensio‐actifs, le dodécylhydrogénosulfate sel de sodium (L.S.S.) et Teepol, dans l'intervalle 200

ISSN:0008-4034    

DOI:10.1002/cjce.5450700303

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe paper deals with the experimental investigations carried out to evaluate holdup for gas‐non‐Newtonian (pseudoplastic) liquid mixtures in vertical and horizontal flow in pipes. Correlations developed predict holdup in slug flow regime with acceptable statistical accur

ISSN:0008-4034    

DOI:10.1002/cjce.5450700304

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

年代:1992

数据来源: WILEY

摘要:

AbstractAxial bed depth profiles were experimentally measured in a rotary kiln containing ilmenite particles under steady state and transient conditions. The variables include feed rate of solids, inclination and rotational speed of the kiln. and dam height. The variation of the axial velocity with kiln axis was estimated. The semi‐experimental model proposed by Perron and Bui (1990) was modified to include the effect of the variables of the present study. The mean residence time of solids was estimated from the fractional hold‐up and expressed in terms of the process variables. The transients induced by a step change in any of the operating conditions were measured as variation of discharge rate of solids with t

ISSN:0008-4034    

DOI:10.1002/cjce.5450700305

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

年代:1992

数据来源: WILEY

摘要:

AbstractFouling resistances of solutions of olefins in kerosene were measured on a hot wire probe and an annular probe operating in parallel at liquid temperatures of about 80°C and heat fluxes from 180‐350 kW/m2. Straight chain terminal olefins, octene‐1 and decene‐1 showed little fouling, whereas hexadecene‐1, and the cyclic olefins 4‐vinyl‐cyclohexene, indene and dicyclopentadiene all showed marked fouling. The effects of heat flux, air versus nitrogen saturation, and the presence of an inhibitor were determined. The probable mechanism of fouling

ISSN:0008-4034    

DOI:10.1002/cjce.5450700306

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

年代:1992

数据来源: WILEY

摘要:

AbstractA numerical analysis was carried out to investigate the effects of film vaporization on natural convection heat and mass transfer in a vertical tube. Results for interfacial Nusselt and Sherwood numbers are presented for air‐ethanol and air‐water systems for various conditions. Predicted results show that heat transfer along the gas‐liquid interface is dominated by the transport of latent heat in association with the vaporization of the liquid film. Additionally, the predicted results obtained by including transport in the liquid film are contrasted with those where liquid film transport is neglected, showing that the assumption of an extremely thin film made by Chang et al. (1986) and Yan and Lin (1990) is only valid for systems with small liquid mass flow rates. For systems with a high liquid film Reynolds number, Re10, the assumption of an extremely thin film is seriously in

ISSN:0008-4034    

DOI:10.1002/cjce.5450700307

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe problem of condensation of vapors on a porous plate fin is formulated and the dimensionless heat transfer coefficients are found to be dependent on two system variables, viz., the fin and the porosity parameters. Numerical simulations indicated that the condensation heat transfer coefficients for a porous fin are larger than those for a non‐porous one of similar cross‐section. For design purposes, a dimensionless equation for predicting the mean condensation heat transfer coefficient is proposed.The significant increase in the condensation heat transfer coefficient suggests that the condenser section of a flat plate heat pipe can be made more efficient in operation with the use of porous plate fins instead of impermeable fins of similar cross‐se

ISSN:0008-4034    

DOI:10.1002/cjce.5450700308

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe convective batch drying of Western Hemlock hog fuel‐sized particles in fixed beds under various operating conditions quantiatively established the effect of factors which govern the drying process. A correlation was obtained for the Nusselt number during the heat transfer controlled period. Under specific conditions, the existence of a unified characteristic drying rate curve was confirmed. Drying behaviour as described by the receding plane model provided a mathematical expression for such a curve. The existence of an inversion point temperature was experimentally confirme

ISSN:0008-4034    

DOI:10.1002/cjce.5450700309

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

年代:1992

数据来源: WILEY

摘要:

AbstractAbsorption rates for CO2into aqueous solutions of TEA, MDEA and blends of MEA with MDEA and TEA were measured in a stirred cell by a method similar to that used by Laddha and Danckwerts (1981). Second order rate constants for CO2‐TEA and CO2‐MDEA were obtained from the single amine data for temperatures in the range of 25‐60°C.A modified pseudo first order model based on the film theory is used to predict the rate of absorption of CO2into mixed amine solutions. This model accounts for the variation of amine concentration in the film and assumes a shuttle mechanism for rate enhancement. Bulk liquid concentrations of the various species present are obtained from a simplified thermodynamic model. The model predicts absorption rates that are in agreement with experimental measur

ISSN:0008-4034    

DOI:10.1002/cjce.5450700310

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

年代:1992

数据来源: WILEY

摘要:

AbstractKnowledge of intraparticle reactant and product diffusivities is important for catalytic reaction engineering purposes, including systems where enzymes or microbial cells are entrapped within hydrophilic gel particles. In this work, a Bayesian regression method was applied to estimate diffusivities from dynamic solute uptake experimental data. This method accounted for non‐uniformity in the particle sizes. Typically, diffusivities are experimentally determined for these gel matrices by monitoring the dynamic uptake of a solute into several hundred small particles. The diffusivity is then estimated using a mathematical approach based on a single particle case. This approach is only appropriate when variations in radius are small. The Bayesian regression technique was found to be suitable for accounting for the nonlinear effect of radius distribution on diffusivity estimates. It was also possible by this method, to incorporate experimental data for partition coefficients, so that appropriate confidence limits on the diffusivity estimate could be obtaine

ISSN:0008-4034    

DOI:10.1002/cjce.5450700312

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

年代:1992

数据来源: WILEY