Том 50, № 3 (2016)

An experimental and numerical study of the gas projectile mass transfer when moving in an inclined pipe has been carried out. The mathematical model is based on the smoothed particle hydrodynamics method and verified by experimental data. The dependence of the velocity of the gas projectile motion and effective dimensionless mass transfer coefficient on the pipe inclination angle has been found. The simulated and calculated from experimental data bubble profiles have been compared.

An estimate has been obtained of the energy consumption on 1 mol of separated mixture based on thermodynamic balances for processes that use mechanical and heat energy. Only irreversible losses depend on the order of separation for mixtures in mechanical systems, while for the systems using the heat, the order of separation also affects the reversible energy consumption. In the latter case, in order to obtain a reversible estimate of the heat consumption, one should solve the problem of selecting the order of separation. An algorithm has been obtained for its solution that enables one to approximately choose the order of separation at the stage of preliminary calculations knowing only the properties of the feed.

The problem of the growth of hydrate particle in an aqueous solution of gas, the intensity of which is determined by the diffusion of gas to its surface, is considered. An analytical solution that enables one to determine the law of growth depending on the concentration of the hydrate-forming gas in water and hydrate, as well as the diffusion coefficient, has been obtained.

A new class of exact solutions has been obtained for three-dimensional equations of themal diffusion in a viscous incompressible liquid. This class enables the description of the temperature and concentration distribution at the boundaries of a liquid layer by a quadratic law. It has been shown that the solutions of the linearized set of thermal diffusion equations can describe the motion of a liquid at extreme points of hydrodynamic fields. A generalization of the classic Couette flow with a quadratic temperature and concentration distribution at the lower boundary has been considered as an example. The application of the presented class of solutions enables the modeling of liquid counterflows and the construction of exact solutions describing the flows of dissipative media.

The problem of suspension filtration has been considered with allowance for the formation of a precipitate by sedimenting disperse particles in one-dimensional formulation. The behavior of a suspension is described with a set of equations for the one-dimensional inertialess motion of a two-phase mixture, and the motion of a liquid through a porous precipitate layer has been described with a filtration equation based on the Darcy law. The particular (limit) cases of an equidense suspension (when the densities of both solid and liquid phases are equal) and an equilibrium suspension (when the sizes of particles are small enough to neglect their sedimentation) and the asymptotic case when the density of disperse particles is much greater than the density of a liquid phase have been studied. Some formulas for the characteristic times of disperse phase sedimentation and liquid filtration have been derived. The limit regimes of slow filtration and slow sedimentation are analyzed. In the general case, the problem has been solved in implicit form.

Some results of an experimental study of liquid film flow over the surface of a structured packing with a new design for heat and mass exchangers were presented. The influence of the irrigation density on the overflow of liquid from one side of a packing element to the other side was studied. The overflow of liquid from one side of a packing element to the other side was shown to occur abruptly upon attaining a certain irrigation density. A dimensionless quantity, namely, the overflow number, was proposed for estimating uniformity in the distribution of a liquid film over a structured perforated packing bed.

The problem of the membrane separation of a helium–methane mixture containing 0.1 wt % He, which imitates the composition of a helium-rich natural gas field, has been numerically analyzed. The helium and methane flux distribution along the length of a flat-sheet membrane module have been calculated. The distribution of the average mass concentration of helium in the channels is presented. The gas pumping expenditures have been estimated. The optimal working parameters of the gas mixture have been determined. Heating the mixture above 400 K does not enhance the helium–methane separation efficiency.