Известия Томского политехнического университета: Инжиниринг георесурсов (Jan 2018)
Hydrodynamic research of shock-spray packing layer in irrigation mode
Abstract
The relevance of the work is caused by the lack of data in scientific literature on hydrodynamic characteristics of the new high-efficiency shock-spray packing intended for gas-liquid mass-exchange processes. The hydrodynamic characteristics of the packing are necessary for the reliable design of such mass exchange equipment for petrochemical industries as absorbers, desorbers, rectification columns, etc. The main aim of the study is to determine experimentally the hydraulic resistance and the magnitude of the splash carrying away on a new shock-spray packing at various relative gas velocities and irrigation densities and on the basis of the data obtained, compare the hydrodynamic characteristics of the shock-spray packing with the known contact devices. The methods: experimental determination of hydraulic resistance and the size of the splash carrying away on the irrigated shock-spray packing, the weight method for determining the splash carrying away, and the instrumental determination of gas and liquid flow rates. The results. The authors have obtained a database of experimental data on hydraulic resistance and splash carrying away in the layer of a new high-efficiency shock-spray packing in a wide range of relative gas velocities and irrigation densities. It is found that for the shockspray packing the hydraulic resistance increase is observed with growth of relative gas velocity. It is shown that the hydraulic resistance of the shock-spray packing is below the resistance of the regular structural-ring packing PSI in 2,5-8,1 times, and below the resistance of the regular sheet corrugated packing in 5,0-8,57 times in the corresponding ranges of relative gas velocities. With relative gas velocities of 0,7-1,0 m/s, the hydraulic resistances of the shock-spray packing and the roll-up grid are commensurable. It is shown that the shock-spray packing stably operates at high gas loads exceeding in 2,06-4,67 times the gas load on the known packings. It is found that the dependence of the splash carrying away on irrigation density for the shock-spray packing is of an extreme nature, with the splash carrying away-well curves having two maxima. The appearance of the maxima of the splash carrying away is explained by the change in hydrodynamic regimes characterized by a different intensity of spraying of the liquid jets during interaction with the gas. It is shown that the relative gas velocity, at which the splash carrying away begins, is 2,9 times higher on the shock-spray packing than in the hollow spray absorber and 2,16 times higher than in the apparatus with straight-through contact devices. At gas velocities of 3,48-4,00 m/s, the splash carrying away on the shock-spray packingis up to 2,61 times lower than that in the hollow spray absorber. The low splash carrying away provides high efficiency of mass-exchange processes on the shock-spray packing, that makes the packing promising for use in the petrochemical industry.
