Showing papers in "Chemical Engineering Science in 1987"

TL;DR: In this paper, the dynamics of complex isothermal reactors are studied in general terms with special focus on connections between reaction network structure and the capacity of the corresponding differential equations to admit unstable behavior.

TL;DR: In this article, the authors studied the kinetics of methane hydrate decomposition using a semibatch stirred-tank reactor and showed that the decomposition rate was proportional to the particle surface area and to the difference in the fugacity of methane at the equilibrium pressure and the degradation pressure.

TL;DR: An intrinsic kinetic model with only one adjustable parameter is proposed for the formation of methane and ethane gas hydrates in this article, where the formation rate is proportional to the difference in the fugacity of the dissolved gas and the three-phase equilibrium fugacity at the experimental temperature.

TL;DR: Crosslinked poly(N-isopropylacrylamide) gel and crosslinked copolymers of 97% N,N-diethyl-acrylide and 3% sodium methacrylate which are swollen with water collapse abruptly at 33°C and near 55°C, respectively.

TL;DR: In this paper, an approximatif de la difference moyenne logarithmique de temperature d'un echangeur de chaleur is given. But this is not the one we use in this paper.

TL;DR: In this paper, the dependence of axial and radial Peclet groups for dispersion of mass upon the Schmidt and Reynolds groups is correlated throughout the range of Reynolds number by fundamentally-based equations for beds of spherical and cylindrical particles.

TL;DR: In this article, an intrinsic kinetic model for the growth of the gas hydrate is proposed, which is based on the crystallization theory coupled with the two-film theory for the gas absorption into the liquid phase.

TL;DR: A theoretical model for volumetric mass transfer coefficients in bubble columns has been developed in this paper, based on Higbie's penetration theory and Kolmogoroff's theory of isotropic turbulence.

TL;DR: Les modifications du modele de Pedersen, utilise pour determiner les viscosites du petrole and du gaz, concernent l'extension de son application aux hydrocarbures lourds and au methane a basse temperature.

TL;DR: In this paper, the authors studied paste rheology with a ram extruder in which there is convergent flow followed by extrusion through a tube of constant diameter, the die-land.

TL;DR: In this paper, a shear-induced hydrodynamic diffusion mechanism is proposed to describe the lateral migration of particles away from the porous wall as the layer is sheared, and a criterion is found for predicting whether or not a stagnant particle layer will form on a porous wall.

TL;DR: In this paper, a review brings attention to much of the recent literature describing these developments and their applications, particularly regarding complex and chaotic oscillations, as well as reported experimental observations which, in many cases, have provided support for prior theory and in many others, have led to new theoretical developments.

TL;DR: In this paper, the average peak power number Po is dependent on the disc thickness (χ 1) to impeller diameter (D) ratio and to the vessel diameter (T).

TL;DR: In this article, a case study of a partitioned-pipe mixer is presented to exemplify the application of theoretical concepts relating fluid mixing in deterministic chaotic systems, where the authors exploit the connection between the kinematics of mixing and the theory of dynamical systems.

TL;DR: In this paper, a pragmatic approach to the study of the compaction behavior of a wide variety of pharmaceutical and other materials has been proposed, based on the measurement of yield pressure during compression, the variation of the yield pressure with punch velocity and on literature values of indentation hardness and Young's Modulus of elasticity.

TL;DR: In this paper, the applicability of the Kolmogoroff-Hinze theory of droplet break-up in a turbulent liquid was tested over a range of local power dissipations per unit mass of liquid from 5 to 109 W kg−1.

TL;DR: In this paper, the distribution of glass beads in suspension in a stirred tank was examined as a function of the stirrer type, and the size and concentration of the solid particles, and a dimensionless number was theoretically derived, and was able to correlate the variation in the quality of the suspension, for a given geometric system.

TL;DR: In this paper, the equations of change for a fluidised suspension are closed by application of a simple model for the interaction of a single particle with the fluid; this relationship delivers the total force on elements of the particle phase including a fluid dynamic formulation for the'particle phase pressure gradient '; numerical solutions of the non-linear equations, for small imposed perturbations of voidage, show clearly the development of shocks (bubbles) for unstable (aggregate) beds and the return to the homogeneous state for stable (particulate) systems.

TL;DR: In this paper, it was shown that there is a univocal relationship between cluster formation and the experimentally observed solubility enhancement in dilute mixtures of non-volatile solutes in supercritical solvents.

TL;DR: In this paper, the Stokes and Brinkman equations were used to solve the Creeping Flow Past a Solid Sphere with a Porous Shell (CF-shell) problem, where the dimensionless solid core and shell radii normalized by the square root of the shell permeability are the two parameters that govern the flow.

TL;DR: In this paper, the authors examined the cake filtration fouling model for reverse osmosis (RO) and found that it is physically unrealistic for flux decline due to calcium sulphate precipitation fouling.

TL;DR: In this article, the authors analyzed the influence of the coefficient of molecular diffusion on mass transfer in gas-liquid stirred vessels with horizontal interfaces which appeared to the eye to be completely smooth.

TL;DR: In this paper, the rate of calcination of dolomite was investigated at atmospheric pressure and also at pressures of 3, 6, 12 and 18 bar, for bed temperatures varying from 1073 to 1248 K. The results indicated that under these conditions the calcination was controlled by chemical reaction at a sharp interface between CaCO3 and CaO.

TL;DR: In this paper, Monte Carlo simulations of the diffusion of a gas molecule in a porous solid are presented, the latter being more rigorous and presenting a different insight into the concept of tortuosity.

TL;DR: In this article, a model for predicting two-phase flow splitting in a horizontal pipe tee for the stratified wavy and annular flow patterns is presented based on a splitting mechanism which suggests that the preferential liquid flow is controlled by competing inertial and centripetal forces acting on the liquid phase at the tee junction.

TL;DR: In this paper, a review of practical situations where wear by particulates can occur is presented, and the dependence of erosive wear on flow parameters, particle properties and material properties is discussed.

TL;DR: In this article, a model is introduced which describes the liquid holdup and the axial pressure gradient in co-current gas/liquid flow in horizontal tubes with a small liquid hold up (eL s$0.04), mainly covering the stratified-wavy and annular flow regimes.

TL;DR: A review of the state of the art of continuation methods can be found in this article, where a discussion of the tracing of parameter dependent branches of solutions is presented and several examples illustrate the procedures.