Physical flow characteristics of a gaseous mixture with solid inclusions

Abstract

The physical characteristics of the flow of a gaseous mixture with solid inclusions in a counterflow with a liquid in a cylindrical pipe is of major interest in analyzing production equipment and processes, making it possible to formulate proposals relative to improvement in the quality and effectiveness of distillation columns. This paper cites results of analyses in the above-indicated problem based on analysis of forces that develop as a result of particle-particle interaction, and particle interaction with the surrounding medium, and forces that develop as a result of particle collisions. The frequency of particle-particle collisions, which limits the adequacy of this model with consideration of solid-particle concentrations, is based on the analyses. Experimental data are obtained for different regimes: in a fluidization regime, where a liquid and gaseous mixture with solid inclusions are delivered from below into a counterflow within the vessel, and in a film regime. More precise definitions, which made it possible to improve the adequacy for the processes under investigations, were made in reducing the experimental data.Mass-transfer units [2, 3] used for hydrodynamic and hydroaerodynamic testing of packed vessels in a three-phase medium are examined for experimental determination of empirical data to compare with computed model data in [1]. A schematic of one of these plants is shown in Fig. 1, and consists of the following components: vertical column vessel, fan with an air duct, and water-supply, -heating, -distribution, and -collection systems. Heat-and mass-transfer characteristics of the packing are studied on this unit during evaporative cooling with indirect contact in an air-water system under counterflow conditions.Column 1 with a diameter of 400 mm has downcomer type of detachable support-distribution grating 2. Packing 3 fills a plate. The layer of packing was set in motion by an ascending gas flow delivered by high-pressure fan 4, and made it possible to effect linear gas velocities of from 1 to 4 m/sec within the column.Liquid from tank 12 was fed by pump 13 through special sprayer 5 uniformly over the surface of the packing, and owing to its irregular movement, created a stable hydrodynamic layer on the surface of the downcomer plate. The liquid then entered the lower section of the vessel, where it was discharged by pump 11 into tank 12. The specific irrigation surface attained 1-5 m 3 /m 2 ·h.The sheets enclosing column 1 are made of acrylic plastic, permitting observation of the three-phase layer, and also measurement of its dynamic height.The following were measured during the course of the hydrodynamic investigations: the hydraulic resistance of the plate with a three-phase layer of irrigated packing, the dynamic height of the layer, and the volume of liquid maintained in the layer.The flow rate of air was measured by Pitot tube 9, which was connected to micromanometer 10. The error of the measurements was ±1.5%.

The use of industrial wastes from machine-building enterprises as packing materials for small-sized absorbers for gas emissions purification

“…The selection of well-known and the creation of new contact packing devices for technological mass transfer equipment is always associated with the need to evaluate their effectiveness for the conditions of a particular process. Work on improving mass transfer contact devices has been very active, and this has been the subject of numerous studies by many leading scientists [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The main tasks that contact mass transfer devices are designed for are developing the inter phase surface and implementing the developed hydromechanical regimes providing mutual mixing and activation of diffusion processes between the contacting components of mass transfer processes.…”