Flow Characteristics Experimental Study On The Liquid-Solid Circulating Fluidized Bed In Horizontal Pipe

The velocity of the particle, the particle concentration and pressure drop of pipe have been studied with a CCD image recording and processing system in the experimental equipment of horizontal pipe liquid-solid circulating fluidized bed. The results show that solids holdup increases with the increasing of flux when liquid flux is less then 1.6m³.h^-1, and solids holdup changes very small when liquid flux is greater then this valve;solids holdup increases with the increasing of particle volume density. The particle density asymmetry degree decreases with the increasing of flux when flux is less then 1.6m³.h^-1, and the value of particle density asymmetry degree at this flux is the minimum;the particle density asymmetry degree decreases with the increasing of liquid density also. The particle axial velocity increases with flux, the maximum of particle axial velocity is the axial velocity of particle in center of pipe;the particle axial velocity is affected greatly by liquid viscosity, the more of the liquid viscosity, the less of the particle axial velocity at same position. The pressure drop of pipe increases with increasing of flux, liquid density, liquid viscosity, particle density and particle volume density. In a word, the velocity of particle, the particle concentration and pressure drop of pipe are affected by character of particle, character of liquid and operating parameters of fluidized bed. The correlation formulas of the particle density asymmetry degree and the pressure drop of pipe are formed by setting up linearity regression model, and the experimental results are agreed with the calculated results.