摘要:

AbstractA variety of constitutive equations have been proposed in recent years to describe the behaviour of polymer solutions and melts. Rather complete reviews of most of the differential and integral equations proposed prior to 1967 have been given by Spriggs, Huppler and Bird(1)and by Bogue and Doughty(2,3). Since then, numerous efforts have been directed towards the development of equations capable of predicting adequately nonlinear and transient properties of polymer solutions and melts.Considerable information can be found in the recently published works by Bird et al.(4,5).Some of the more successful models are presented here in an uniform notation. The models are evaluated in terms of their ability to simultaneously describe some or most of the rheological functions such as the non‐Newtonian viscosity, the normal stress difference functions, the components of the complex viscosity, stress growth and stress relaxatio

ISSN:0008-4034    

DOI:10.1002/cjce.5450570102

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

年代:1979

数据来源: WILEY

摘要:

AbstractPseudo‐first order chemical absorption was used as the basis for determining the effective interfacial area available for mass transfer in gas‐liquid, cocurrent, upward pipe flow. The study, which was performed in a 2.54 cm I.D. tube, encompassed the slug and froth flow regimes.The interfacial area displayed a strong dependence upon the coordinates of the flow regime map proposed by Oshinowo and Charles(16). In addition, the systematic variation of surface area could be rationalized on the basis of flow regime geometry. Unfortunately the data could not be used to assess previous surface area models due to the unresolved diameter dependence of these models.Observations are also made concerning the apparently significant effect of chemical composition on interfacial surface area, and concerning the inadequacy of the popular methods used for estimating frictional pressure drop in vertical two‐phase

ISSN:0008-4034    

DOI:10.1002/cjce.5450570103

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

年代:1979

数据来源: WILEY

摘要:

AbstractThermal conductivities of γ‐alumina and alumina supported nickel catalysts prepared by impregnation and coprecipitation have been measured by a transient method. Results obtained were compared with predictive models and it was found that a simple modification' of a one parameter model gave good agreement with the results for the support and impregnated catalysts but did not give satisfactory predictions for the coprecipitated cataly

ISSN:0008-4034    

DOI:10.1002/cjce.5450570104

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

年代:1979

数据来源: WILEY

摘要:

AbstractCoalescence times, measured by high speed cinematography, are reported for n‐hexane droplets formed and grown on adjacent nozzles in equilibrated aqueous solutions of ethanol, n‐butanol, n‐hexanol, n‐octanol, n‐decanol and n‐dodecanol. The drops remained attached to the nozzles throughout the coalescence process. Coalescence times increased when alcohols were added to the system. Very similar results were obtained for the alcohols n‐hexanol to n‐dodecanol. When these alcohols, which are much more soluble in n‐hexane than in water, were present, the observed coalescence times could be accounted for best by considering diffusion processes occurring in the n‐hexane. For ethanol and n‐butanol, which are more soluble in water, diffusion processes occurring in the water had to

ISSN:0008-4034    

DOI:10.1002/cjce.5450570105

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe interphase rate process for the extraction of mercaptan sulfur from n‐pentane with a 10% caustic solution is examined. The system represents a case of mass transfer with an equilibrium chemical reaction occurring in one phase. Experimental studies were made with both a continuous flow stirred tank reactor (CFSTR) and an annular flow jet reactor (AFJR). The interphase volumetric mass transfer coefficient (KLa) was derived based on Olander's theory. The KLa data for each contactor was found to be a function of the power input per unit volume. The AFJR exhibited higher KLa values and equilibration of mercaptan sulfur was achieved in about three millisecond

ISSN:0008-4034    

DOI:10.1002/cjce.5450570106

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

年代:1979

数据来源: WILEY

摘要:

AbstractA new sequential continuous chromatographic refiner (SCCR‐2) for high temperature production scale G.L.C. (gas‐liquid chromatographic) separations is described. In this equipment the counter‐current movement between the gas and liquid phase is simulated by sequencing a system of inlet and outlet port functions around twelve static 2.54 cm internal diameter and 61 cm long stainless steel columns. The versatility of the equipment has been demonstrated by the separation of equivolume mixtures of the halocarbons arklone P/genklene P, methylchloroacetate/ethyl lactate and ethyl caprate/ethyl laurate at temperatures of 60°, 105° and 160°C respectively. Throughputs between 21–75 cm3h−1have been explored with product purities in excess of 99.8% achieved under certain proces

ISSN:0008-4034    

DOI:10.1002/cjce.5450570107

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

年代:1979

数据来源: WILEY

摘要:

AbstractAn experimental comparative analysis of various factors involved in the separation of styrene‐ethylbenzene mixtures by liquid membrane permeation was performed.The choice of the proper surfactant and the influence of the ratio surfactant/solvent/feed and of the operating parameters were investigated.An attempt is made to interpret the experimentally determined characteristics of the system on the basis of a diffusive model adapted to this kind of separatio

ISSN:0008-4034    

DOI:10.1002/cjce.5450570108

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

年代:1979

数据来源: WILEY

摘要:

AbstractMass transfer coefficients inside single rising bubbles are measured in the system SO2, N2—H2O by using a photographic technique.The differential equations which govern the phenomena, including internal toroidal circulation inside the bubble, are also presented. Assumptions are incompressible, steady, irrotational outside flow and inviscid, steady, axisymrnetric inside flow.From the mass transport viewpoint, restrictions are: binary dilute mixture and axial symmetry.The theoretical solution is presented as Sh vs. Pe and a comparison with experiments shows good agreement.Theoretical predictions for a stagnant fluid inside the bubble were also compared with the experimental result

ISSN:0008-4034    

DOI:10.1002/cjce.5450570109

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe coupled diffusion equations describing transport in a bi‐porous adsorbent (micropore‐macropore) have been solved in order to obtain the theoretical uptake curves for such a system when the adsorption equilibrium isotherm is rectangular. Solutions are presented for both the step change boundary condition generally encountered in adsorption from the gas phase and for the more complex case which is encountered in studies of adsorption from the liquid phase, when the composition of the ambient fluid changes significantly during the course of an experiment. The theoretical uptake curves are compared with the corresponding curves for a linear sys

ISSN:0008-4034    

DOI:10.1002/cjce.5450570110

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

年代:1979

数据来源: WILEY

摘要:

AbstractExperimental kinetic uptake curves for two sorbates (cis‐2‐butene from the gas phase and n‐heptane from the liquid phase) have been measured in a variety of 5A molecular sieve pellets. Conditions were selected to fulfil either the linear isotherm approximation of the Ruckenstein(3)model or the rectangular isotherm approximation of the preceding paper. For these systems both macropore and micropore diffusional resistances are significant and it is shown that the theoretical models provide a satisfactory interpretation of the experimental uptake curves. Time constants for both macropore and micropore diffusion, calculated by matching experimental and theoretical uptake curves, are consistent with independently measured v

ISSN:0008-4034    

DOI:10.1002/cjce.5450570111

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

年代:1979

数据来源: WILEY