分支管气固两相流动阻力性能的研究

在水平T型分支管道中,用压缩空气对平均粒径分别为0.25 mm和0.5 mm的砂石进行气力输送试验,对气固两相流动的阻力性能进行研究.试验结果表明,在发送压力保持不变的情况下,当输送气速逐渐下降时,分支管的单位长度压差在开始时减小,但当输送气速下降到一定程度后,单位长度压差下降趋势减缓,有时甚至转而增大;当分支管路流量控制阀开度差值由小变大时,两分支管路中颗粒产生沉积时的临界速度发生相反方向的变化,且平均粒径较小的颗粒临界速度相对较大.

Study on the resistance properties of gas-solid two-phase flow in branch pipe

The resistance properties of gassolid twophase flow in branch pipe are expatiated.The pneumatic conveying experiments for sand with average particle diameter 0.25 mm and 0.5 mm are carried out by using compressed air in horizontal Tbranch pipe.The results show that under the condition of the systemic operation pressure keeping to a constant value,when the conveying velocity gradually descends,the unit length pressure drop of the branch pipe gradually declines at first,however when the conveying velocity reduces to some extent,the pressure drop descends slowly,sometimes the pressure drop even begins to rise.When the difference value of the flow valve opening degree of the respective pipe is raised,the critical velocity of the respective branch pipe changes in reverse direction.Under the experimental condition of the paper,the less average diameter particle is,the higher the critical velocity is.