Showing papers in "Chemical Engineering Science in 1971"

TL;DR: In this article, a bidisperse model for transient diffusion in porous systems consisting of small spherical particles is presented, which describes sorption in pelletized particles and in some types of molecular sieves and ion exchange resins.

TL;DR: In this paper, the root-mean-square fluctuating concentration is supposed to obey a parabolic differential equation containing terms for convection, diffusion, generation and dissipation, and the initial and boundary conditions are appropriate to the steady injection of fluid from a nozzle of circular cross-section into a reservoir containing stagnant fluid of equal density.

TL;DR: In this paper, a method for the calculation of optimum cooling curves based on a simple mathematical description of the individual kinetic processes involved in a crystallization operation is presented, and the results show that the programmed cooling brings about a significant increase in the size and an improvement in the quality of crystals from a batch crystallizer.

TL;DR: In this paper, a model for deposition of particles and droplets from turbulent gas streams is presented, which is largely free of the assumption and limitations of earlier methods, providing for the possibiity that the eddy and particle motion are not identical.

TL;DR: In this article, a structural model is presented for the non-catalytic reaction between a porous solid and a gas stream, which incoporates parameters such as solid grain size, porosity, effective pore diffusion coefficient and allows the quantitative assessment of the role played by these in determining the overall reaction rate.

TL;DR: In this article, a simple perturbation criterion is derived for the minimum reactor length required for freedom from significant axial dispersion effects in trickle-flow laboratory reactors, and it shows that the minimum length increases with both conversion and reaction order, and is inversely proportional to the Bodenstein number.

TL;DR: In this article, trajectories for particles in the path of a spherical bubble rising in an infinite pool of liquid are calculated from grazing trajectories, and collision efficiences corresponding to values of a particle inertia parameter K down to 0·001 and a particle gravity parameter G up to 0.3 for both Stokes and potential flow fields around the bubble.

TL;DR: In this article, the general relation between diffusivities in dilute liquid solutions and solvent viscosities for non-complexing systems was reviewed, and it was found that in general diffusivity and solvability were not inversely related.

TL;DR: In this paper, the hydrodynamic force on a small particle of a dilute suspension when in a slow streaming motion past a large spherical or cylindrical obstacle is estimated for the situation when the particle is moving close to the obstacle.

TL;DR: In this article, the effect of heat of reaction is considered based on the zone reaction model presented in Part I. The experimental thermal and transitional instabilities are compared with those from the grain model.

TL;DR: In this article, the theory of absorption with slow chemical reaction was used to obtain effective interfacial area, a, in mechanically agitated vessels, and the liquid-side mass transfer coefficient, kLa, was found by using the theory.

TL;DR: In this paper, the equations governing a packed bed reactor with radial temperature and concentration gradients are solved using the orthogonal collocation method, which is shown to be faster and more accurate than finite difference calculations.

TL;DR: In this paper, the concept of effectiveness factors in relation to crystal growth studies is introduced, which allows a quantitative measure of the degree of diffusion or surface integration control to be made, and with the aid of the effectiveness factor the dangers of interpreting growth rate data as representing the surface integration rate are pointed out.

TL;DR: In this article, the effect of Reynolds number, Grashof number and Schmidt number on mass transfer rates in packed beds is investigated and it is suggested that an improved method for interpreting mass transfer results is to determine asymptotic relations for different ranges of variables.

TL;DR: In this article, the average properties of the liquid film are given by summing the contributions from the roll waves and from the base film, and a mathematical model is developed to determine the profiles of height, wall shear stress and gas pressure.

TL;DR: In this article, a swarm of air bubbles was dispersed in aqueous electrolyte solutions, and the effects of the salts on the interfacial area of dispersion and on the oxygen transfer coefficient were investigated at various salt concentrations.

TL;DR: In this paper, the attraction between floating particles is caused by interfacial tension and buoyancy forces that have defied calculation so far owing to the complicated shape of the intervening meniscus.

TL;DR: In this paper, the rate constants for adsorption and surface reaction were derived for a fixed-bed catalytic reactor with axial dispersion, particle-to-fluid diffusion, intraparticle diffusion, adaption, and a surface reaction.

TL;DR: In this paper, six types of bubbling action in the dynamic regime are distinguished for "inviscid" flow into a deep pool from a single orifice over a chamber of finite capacity: single and double bubbling, with and without delayed release; pairing and doublepairing.

TL;DR: In this paper, the effect of incorporating different degrees of cluster addition into the simulation model of floc structure was investigated. But the results showed that the cluster addition models predicted a structure of lower density than is observed.

TL;DR: In this paper, the problem of calculating the diffusivities of gases in molecular sieves from experimental sorption curves is discussed, and it is shown that both the shape and the size distribution of the crystallites have significant effects on the sorption curve.

TL;DR: In this paper, the relative motion of vertically aligned bubble pairs, each having volumes from 10 to 40 cm 3, in a 67 per cent wt solution of sucrose in water, was investigated.

TL;DR: In this article, the authors extended the shock layer theory to axial dispersion and applied it to the nonequilibrium exchange system with a moving coordinate scheme to establish the existence condition and uniqueness of the shock layers.

TL;DR: In this article, a simple two-stage model was proposed for the formation of gas bubbles at a plate orifice submerged in an inviscid liquid, applicable at high gas injection rates.

TL;DR: In this article, the authors investigated the effect of wire spiral spanners on the degree of separation of a continuous-type concentric tube thermal diffusion column by means of a wire spiral, having a diameter equal to the annular spacing and inserted as a spacer.

TL;DR: In this article, an expression for the eddy diffusivity in the turbulent boundary layer near a smooth wall for fluids of high Prandtl number is obtained from emperical considerations.

TL;DR: In this paper, the facilitated transport of CO 2 through thin layers of bicarbonate solution has been investigated and the results have been obtained using a new experimental technique which permits flux studies on immobilized films as thin as 100 μ.

TL;DR: In this paper, a formulation and computed results for the growth of a spherical gas bubble in a supersaturated liquid, due to solute diffusion, are presented in a dimensionless form and the appropriate dimensionless parameters allow a more general representation of the effects of surface tension, viscosity and liquid inertia.

TL;DR: In this article, a geometrical model is developed for the sphere resting at an interface, which successfully predicts the angle subtended with the axis of symmetry by the interface in contact with the sphere.