基于颗粒简化动力学方程的液固分选流化床数学模型

利用四阶Runge-Kutta法求解了液固分选流化床内颗粒的简化动力学方程，得到了颗粒速度和位移等随时间变化关系，并搭建了流化试验系统，验证了颗粒简化动力学方程的准确性，其预测的颗粒干扰沉降末速相对偏差基本可控制在5%以内。建立了基于该简化动力学方程的液固分选流化床数学模型，与试验分选结果相比，各密度级颗粒分配率的均方根误差为5.05。利用该模型探究了入料速率对颗粒分离结果的影响，发现入料速率增大导致的床层有效密度与实际分选密度比值减小是该过程中液固流化床分选效率降低的原因。

A mathematical model for liquid solid fluidized bed separator based on Particles’Simplified Motion Equations

Particles’ simplified motion equations were solved using the fourth order Runge Kutta algorithm and their settling velocities as well as displacements along with time in liquid solid fluidized bed separator were obtained. Fluidization experiment system was set up to verify the correctness of the calculated values of hindered settling velocities from solving particles’ simplified motion equations. The relative error of calculated hindered terminal settling velocities could be kept within 5% overall compared with the experimental values. Then,a mathematical model for liquid solid fluidized bed separator was proposed based on particles’ simplified motion equations. The predicted partition values of different density fractions were validated with separation experiment,demonstrating that the mathematical model used in this work could give a well enough predicted separation result with a root mean square error of 5.05 of all density fractions. Using the mathematical model,the influence of feed rate on the separation results was explored,indicating the decreasing of the ratio of fluidized bed effective density ρeff to δ50 (separation density) was the reason that separation efficiency decreased with the feed rate increasing.