固液流化床中不同粒径粒子群的滑流速度

在稳定的流动状态下,实验考察了铅直管内粒径不同的两组分粒子群的滑流速度,并与每一组分单独存在时的值进行了对比.相对于单组分时的滑流速度,两组分场合的每一组分的滑流速度都会发生偏离并相互接近,偏离的程度受两个粒子群的粒径比、浓度比以及总粒子浓度的影响.通过对两个粒子群之间的相互影响因素的定量分析,以单成分的空隙方程式为基础,建立了在多种操作条件下直接计算滑流速度的模型.

Slip velocity of two-sized particle in a liquid-solid fluidized bed

This work aims to experimentally investigate the slip velocities of two-sized particle in a vertical column.It is observed that the slip velocities of smaller and larger particles increase and decrease,respectively.As compared to those in a single-sized particle system of an identical total solid holdup,the changes in the slip velocity of a dominant component are smaller than those of an accessory component,and not only are the sizes of the two particles approximately the same.The slip velocities increasingly vary for every component.It is also observed that the differences in the slip velocities of both components from those in the single-sized particle system increase with an increase in the total solid holdup,and that the slip velocities of both particles assume approximately identical values when the total solid holdup exceeds approximately 0.5.The slip velocities of the smaller and larger particles in the two-sized particle system are correlated with the total solid holdup,the ratio of the solid holdup of each component,and ratio of the particle diameter by a novel model.