摘要:

AbstractThe fluid mechanical behaviour of a bubble swarm was simulated using a cell model. The Navier‐Stokes equations were solved numerically for the liquid flow in a uniform assemblage of circulating, spherical bubbles. Ranges of parameters studied included, Reynolds numbers, 0–1000 and porosities, 0.4–1.The numerical calculations show the effects of variations in Reynolds numbers and porosity on: surface vorticity and pressure distributions and form and friction drag coefficients. For all Reynolds numbers investigated a standing vortex ring was absentPredicted drag coefficients and Sherwood or Nusselt numbers agree with limiting analytical solutions for low and high Reynolds numbers. The theoretical results show good agreement with experimental data for porosity as a function of superficial gas velocity. Predicted and measured Sherwood and Nusselt Numbers were in substantial disagreement, making detailed comparison unwarrantedThe calculations should also be valid for dispersions of uniform, circulating, spherical droplets for the special case where the droplet viscosity is much less than the viscosity of the continuous

ISSN:0008-4034    

DOI:10.1002/cjce.5450490601

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe pressure gradient at a specified flow of air through beds of randomly packed spheres was found to be increased in the presence of sound in the frequency range 500 Hz to 1100 Hz. The phenomenon was studied at several sound frequencies, sound intensities, and flow velocities. A theoretical analysis yielded predictions of the magnitude of the increased pressure drop due to sound which agreed moderately well with experiment

ISSN:0008-4034    

DOI:10.1002/cjce.5450490602

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

年代:1971

数据来源: WILEY

摘要:

AbstractAxial mixing of the liquid phase in trickle flow through two columns packed with Raschig rings was determined by least square fitting of the experimentally obtained F‐curve applying the Fibonacci optimal search method. The Péclet number was found to be independent of the gas flow rate and proportional to the liquid Reynolds number. The one parameter axial dispersed plug flow model was shown to be acceptable in describing axial mixing of the liquid phase. A simple correlation of the Péclet number is proposed for application in mass transfer design calculat

ISSN:0008-4034    

DOI:10.1002/cjce.5450490603

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

年代:1971

数据来源: WILEY

摘要:

AbstractExpansion‐contraction behavior of capillary jets of dilute polymer solutions has been studied by using small diameter capillary tubes. The test liquids were water, glycerine solution and dilute solutions of polyethylene oxide and guar gum. It has been found that polyethylene oxide molecules degraded considerably at high shear rates; however the molecular degradation had little effect on the observed expansion‐contraction behavior of capillary jets. On the other hand, the solvent viscosity had an appreciable effect on the issuing jets and on the final magnitude of the evaluated normal stre

ISSN:0008-4034    

DOI:10.1002/cjce.5450490604

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe secondary flows created by an internal spiral rib in an otherwise conventional smooth tube are illustrated by reference to the axial, and combined tangential and radial velocity components for a fluid flowing in a 2‐inch diameter tube containing a rib with a pitch‐to‐diameter ratio of 3The effect of such secondary flows on the transportability of “settling”(suspensions)was investigated by measuring pressure gradients for the flow of two sand/water slurries in a smooth 2‐inch tube and in 2‐inch diameter tubes with ribs of pitch‐to‐diameter ratio 5.15, 3.32 and 1.80. Average flow velocities ranged from 0.5 to 8 feet/sec. and delivered concentrations ranged from 5 to 18 per cent by volumeWhile the ribs were found to be a disadvantage at relatively high average mixture velocities because of increased pressure gradients, they were found to be advantageous at relatively low velocities, i.e. velocities less than the critical deposit velocity for flow in the smooth tube, in that the pressure gradients, for a given sand/water slurry with a given delivered concentration and average velocity, were lower in the ribbed tubes than in the smooth tube. Because of this, the power consumption per unit mass of solid transported was reduced by the presence of a rib. The optimum pitch‐to‐diameter ratio was estimated to be about 5Pressure gradients measured for one of the slurries with air added as a third phase showed the presence of air to be a

ISSN:0008-4034    

DOI:10.1002/cjce.5450490605

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe agglomeration of two TiO2pigments (0.2‐1.0μ) dispersed in an agitated 1% saline solution has been studied by a sequential count method using a Coulter counter. A model based on collision frequency due to the turbulent motion in a stirred vessel predicts the second order rate constant k to be proportional to agglomerate volume and to stirrer speed to the power 3/2. Experimental values of k were proportional to threshold volume to the power 0.79, stirrer speed to the power 1.3, and independent of TiO2concentrat

ISSN:0008-4034    

DOI:10.1002/cjce.5450490606

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

年代:1971

数据来源: WILEY

摘要:

AbstractA review is presented of the application of solvent extraction to the treatment of waste waters. Methods of extraction, solute‐solvent separation and water — solvent separation are described. Phenol removal, oily water treatment, desalination, metal recovery by “liquid ion exchange” and miscellaneous other applications are described/ Available economic data are discussed. Possible future applications are outlined and it is suggested that greatest potential is in the treatment of oily waste water and of relatively concentrated streams containing valuable or noxious m

ISSN:0008-4034    

DOI:10.1002/cjce.5450490607

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe diaphragm cell method for experimentally determining multicomponent liquid diffusivities is optimized. An exact matrix solution of the coupled, non‐symmetric, first order, linear, differential equations which presents a slightly different viewpoint is given. Optimum experimental conditions are defined for ternary systems for both single determinations and multiples of a single determination. The methods used can be applied to any number of componen

ISSN:0008-4034    

DOI:10.1002/cjce.5450490608

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe diffusion of chlorine in macroreticular chlorine exchange resins was studied by measurement of: (1) experimental concentration‐distance profiles, and (2) overall effective diffusion coefficients D̄. The results were compared to demonstrate that the second method, although simpler, yielded useful results. The transfer mechanism was shown to be pore diffusion where chlorine first diffused into the resin through the pores before being absorbed into the resin around them. Pore diffusion models yielded pore diffusion coefficients Dpof 3.1 x 10‐5to 7.5 x 10‐5cm2/sec. The rate of absorption was controlled by coupled diffusion but the film resistance became negligible after a short time. Effective (D̄) and concentration‐dependent (Ds) diffusion coefficients in the solid phase were in the range of 10‐9t

ISSN:0008-4034    

DOI:10.1002/cjce.5450490609

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe chemical absorption of carbon dioxide by a laminar jet of ethylenediamine has been studied at 25.5°C under pseudo‐first‐order kinetic conditions. The reaction was found to be second‐order with a rate constant of 1.0 x 1051/g. mole sec. Equilibrium calculations at 18°C indicate that the partial pressure of carbon dioxide is very low, even over highly carbonated ethylenediamine solutions. The effects of amine concentration and carbonation ratio on the physical solubility and diffusivity of carbon dioxide in solution were inferred from corresponding results for nitro

ISSN:0008-4034    

DOI:10.1002/cjce.5450490610

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

年代:1971

数据来源: WILEY