The Study On The Motion Characteristics Of Gas-Solid Two-Phase In The Process Of Gas Passing Through Solid-Liquid Two-Phase

The process of gas passing through the solid-liquid two-phase pool exists in the scrubbo-cooling chamber of gasifier,the air flotation treatment of sewage and the high-efficiency flotation of coal.In the process of gas passing through the solid-liquid two-phase pool,gas exists in the form of bubbles.In this process,the solid-liquid two-phase will be disturbed by bubbles,the particles will be shoved,and appear settlement and suspension phenomena.Obviously,the process of gas passing through the solid-liquid two-phase pool is a complex,unsteady,multi-scale and inter-coupling multi-phase flow process.It is necessary to master the flow characteristics in the process of gas passing through solid-liquid two-phase and understand the influence of different factors on the process of gas passing through solid-liquid two-phase from bubble behavior and particle motion.Therefore,the characteristics of bubbles and particles motion and separation characteristics of particles in this process will be studied in this paper,which reveal the inherent law,and provide theoretical guidance for industrial production and engineering application.Physical models about the process of gas passing through solid-liquid two-phase pool is established in this paper.The Euler-Euler two-fluid model is used as the mathematical model.The feasibility of the model was verified by comparison with the experimental results.The process of gas passing through the solid-liquid two-phase pool is simulated by the mathematical model,and the characteristics of bubbles and particles motion under different conditions are studied.The characteristics of the liquid-solid separation in the process of gas passing through liquid-solid two-phase pool are studied.The characteristics of bubble and particle motion in the process of gas passing through the solid-liquid two-phase pool were studied under the conditions of particle size,inlet gas velocity,bubble diameter and immersion mode.The results show that the gas volume fraction decreases with the increase of particle size under the same inlet gas velocity in the solid-liquid two-phase pool under three immersion modes(bottom immersion mode,side immersion mode and top immersion mode).Under the bottomimmersion mode,the Y-direction velocity of gas is the smallest with the diameters of 20?m.the Y-direction velocity and volume fraction of gas under three immersion modes(bottom immersion mode,side immersion mode and top immersion mode)increase with the increase of inlet gas velocity.Under the top immersion mode,the bubble Y-direction velocity decreases as the bubble diameter increases,and the gas volume fraction increases as the bubble diameter increases,and the other two modes are opposite.The Y-direction velocity and volume fraction of particle decrease with the increase of particle size under three immersion modes(bottom immersion mode,side immersion mode and top immersion mode).The Y-direction velocity of particle increases with the increase of gas velocity,and the particle volume fraction decreases with the increase of gas velocity.The Y-direction velocity of particle increases with the increase of bubble diameter under bottom immersion mode and top immersion mode.The Y-direction velocity of particle increases with the increase of bubble diameter under bottom immersion mode and side immersion mode.The velocity and volume fraction of gas and particle distribute symmetrically along the radial direction in the pool under the bottom immersion mode and under the top immersion mode.In order to master the liquid-solid separation characteristics in the process of gas passing through solid-liquid two-phase pool,the evolution process of particle separation and the variation law of particle concentration were obtained.The effects of bubble diameter and immersion modes on the liquid-solid separation characteristics were also found.The results show that the particles with diameters of 500?m are mainly settlement in the pool with time change.The particles with smaller diameters(the diameters of 5?m and the diameters of 20?m)are mainly suspended in the pool,and the sedimentation phenomenon is not obvious,and the particles with diameters of 5?m are more obviously disturbed by gas.These dimentation and suspension phenomena of particles with diameters of 100?m exist in the pool.The solid particle concentration is most different with the increase of bubble diameter under the side immersion mode.Under bottom immersion mode,side immersion mode and top immersion mode,when the particle diameters were 100?m and 500?m,thevolume fraction of particles has little difference,and the effect of liquid-solid separation is not obvious.