Effect Of Concentration In Liquid-Solid Fluidized Bed On Particle Movement In An Inclined Channel

Aiming at the problems for the limitations of the traditional liquid-solid fluidized bed including insufficient handing capacity and ineffective processing of refractory materials,this paper puts forward the idea of combining the fluidization of vertical fluidized bed and the role of inclined channel enhanced sedimentation.And an inclined channel is provided in the upper part of the vertical fluidized bed.The sedimentation movement characteristics based on the terminal velocity of hindered settling in an inclined channel were studied in order to explain the movement rule and the treatment advantage of the sedimentation and separation in the inclined channel of liquid-solid fluidized bed at different feeding concentrations.The paper was bulit on the particles'terminal velocity of hinderd settling,the kinetic model of the relationship of the particle velocity and the rising water velocity,the parameters of the structure and the volume concentration of the particles in the inclined channel is established.The particle model is described in the paper.The movement of sedimentation,separation and just entering the overflow critical movement under different conditions.The equipment model was designed and built,and the experimental system was set up to validate the theoretical model.The idea of describing particle motion trajectory based on particle velocity vector relation is proposed,and the motion model of single settling characteristic particle in inclined channel is established,(?),And through the determination of quartz sand particles with different particle size(0.25-0.425mm,0.425-0.71mm,0.71-0.88mm)of the actual trajectory,the results showed that at low feed concentration when the model predicted value is lower than the measured value in the test,the high feed concentration when the predicted value was higher than that in the test,and the predicted value of the model is basically the same as the experimental value when the feed concentration is 18%.The kinetic model of the single sedimentation characteristic particle is extended to two kinds of sedimentation motion model,and the theoretical model of the sedimentation distance difference in the inclined channel with different sedimentation characteristics is proposed,(?),utilization rate is also proposed,(?)and separation factor (?),The differences between the settling velocity of the particles in the liquid-solid fluidized bed and the settling distance of the particles in the inclined channel is proposed as the mechanism of the inclined channel.The experimental results show thatincreases with feed concentration and fluidized water velocity,but the influent of feed concentration is greater than fluidized water velocity.Effective separation efficiency?and separation factor?of inclined channels are Concentration and fluidized water velocity.When the feed concentration is 12%-22%,? is between 0.2-0.4,and the value of?is between 0.25-0.65.By studying the critical movement state of the particle just entering the overflow,the theoretical processing capacity advantage based on the increasing settlement area is proposed,(?).The theoretical model of particle critical motion in inclined channel is derived,(?).On this basis,the expression of particle separation efficiency is presented,(?).It was found that the critical fluidization water velocity and separation efficiency decreased with the increase of feed concentration under the condition of different feed concentration.When the volume concentration is 8%,the critical fluidizing water velocity is about 2.5 times the final velocity of particle free settling.When the feed volume concentration is 8%-22%,the separation efficiency is between 0.3-0.65.In this paper,the motion model of particle in the inclined channel is established based on the terminal velocity of particle interference,and the experiment is carried out under different feed concentration conditions to illustrate the movement rule of particles in inclined channel in different liquid-solid fluidized bed.The results are of theoretical and practical value for the structural design and operating parameters of inclined channel in liquid-solid fluidized bed.