CALCULATION MODEL OF ENJOYMENT OF DUST PARTICLES BY SWIRKING FLOW IN GAS FLOWES

Abstract

An analysis of the reasons for the formation of deposits in the flue ducts of aspiration systems was carried out. Problems have been noted in removing deposits with compressed air. The purpose of the work is to solve the problems of aspiration systems and reduce the formation of dust deposits in gas ducts. This is possible due to the swirling of the compressed air flow when purging the gas duct. Despite significant pressure losses when organizing flow swirl, compressed air consumption is reduced by 20–40%. A computational model of the entrainment of dust particles by a swirling flow in gas ducts is presented. To describe the physical model of the movement of a dust particle in a swirling gas flow flowing in a gas duct with a circular cross-section, polar coordinates are used. Dependencies have been determined to determine the value of the average axial velocity of the swirling flow required to move a particle along the gas duct. A diagram of the coordinate axes and forces acting on the particle is presented. The forces acting on the dust particle and its connections with the inner surface of the flue are replaced by the reaction of the flue wall. By decomposing the wall reaction into tangential and normal components, differential equations were obtained that describe the motion of the particle. The dust particle is significantly influenced by the forces of resistance to flow around the gas flow F_μ, the friction force on the wall of the gas duct F_fr, the weight of the particle P, the normal reaction of the wall of the gas duct N. Analysis of the fractional composition of various dusts contained in gases aspirated from the equipment of the metallurgical industry and the production of electrode materials showed that For these dusts, the optimal flow is a weak swirl of intensity W*= 0.5–0.8. This swirling intensity can be achieved by introducing a flow of compressed air when blowing at an angle of 36–48°.