The Numerical Simulation And Theoretical Research Of The Influence Of The Suspension Liquid Viscosity On The Cyclone Separation Lower Limit

In this paper,the relationship between the viscosity of the suspension liquid and the separation lower limit of the cyclone is explored.On the basis of the research on the velocity field of the cyclone,the flow field data is obtained by numerical simulation of the fluid mechanics method.the mathematical formula of the flow field is determined by the mathematical method of regression analysis.In previous studies of solid-liquid two-phase flow,thought while the force on solid particles is numerous,but really need to consider in the cyclone only five force:centrifugal force,pressure gradient force and fluid drag force,virtual mass force,Basset force.Combined with velocity formula and force analysis,put forward a theory about the movement of particles in cyclone:particles' "initial fate" differences on the face of feeding inlet;The main task of cyclone separation is letting the coal particles initially in the outer swirl through LZVV before leaving underflow orifice,letting the gangue particles initially in the inner swirl through LZVV before entering overflow pipe;The separation lower limit coal particles will eventually pass the boundary between LZVV and the underflow orifice,and each has a 50%chance to enter into the inner and outer swirl.On the basis of numerical simulation results,the particle tracking of different particle size was obtained,and get the relationship between viscosity and suspension lower limit.This relationship is as same as the result of theoretical analysis which is under the assumption of ignoring the virtual mass force:dynamic viscosity increase n times,n times cyclone separation lower limit increase.Using the velocity formula and the theory about the movement of particles in cyclone to directly calculate the separation limit,found that under the assumption of ignoring the virtual mass force,the calculated value of separation lower limit is almost three times bigger than that in Fluent.Put the assumption of ignoring the virtual mass force aside,because the equations are too complex,failed to conclude the solution,though it could be getted theoretically.The reason is that velocity formula from regression analysis is too complex.