Calculation and implementation of a cyclone-vortex device in chromic sulphate production

Abstract

Traditional gas cleaning schemes are mainly equipped with separate gas cleaning devices that perform the functions of ensuring a given efficiency in cleaning from dust particles and gas components. In this regard, the creation of combined apparatuses combining several zones for carrying out various processes in one apparatus is in demand. Analysis of the operation of combined gas purification devices for purifying multicomponent gases made it possible to develop the design of a cyclone-vortex action device, in the lower zone of which a centrifugal mechanism for collecting dust is realized, and in the upper zone – vortex interaction of a gas-liquid flow in the volume of a regular packing, which provides absorption cleaning. The development and implementation of such devices seems to be relevant. In the manufacture of a laboratory installation, the structural ratios of the cyclone and packed stages of the apparatus of cyclone-vortex action were obtained based on the recommendations for the manufacture of cyclones, as well as the results of research and recommendations for the design of apparatuses with a regular movable nozzle. In the process of research, standard methods for determining the hydraulic resistance and dust collection efficiency were used. Based on the results of laboratory studies, the main calculated dependences of the hydraulic resistance and dust collection parameters of the cyclone and packed stages and the device as a whole were obtained, which, along with the recommendations, were used to calculate and design an industrial device. The cyclone-vortex action device was tested in industrial conditions and implemented in the technological scheme for the purification of gases leaving the boiling bed dryer in chromic sulfate production at Aktobe Plant of Chromic Compounds JSC. According to the results of industrial tests, it was noted that in the cyclone part, the increase in hydraulic resistance with an increase in gas velocity is due to an increase in dynamic pressure and losses associated with a change in the direction of gas movement and friction losses. The effective force acting on suspended solids is the centrifugal force, the magnitude of which is largely determined by the velocity of the gas flow. In the packed zone, the operation of the apparatus proceeds in a drop mode, characterized by a uniform distribution of flows over the cross section of the apparatus, an increase in the turbulence of the gas-liquid flow, and an increase in the intensity and frequency of pulsations. This contributes to an increase in the efficiency of dust collection