摘要
对三种形状六种尺寸的小颗粒填料,在滴流床中气液两相并流向下流动时液相的轴向返混程度作了研究。实验表明:随着液速的增加,填料颗粒的毕克力Pe_L值增大,返混程度降低;填料颗粒的球形度越小,Pe_L值就越小,返混程度就越大;填料颗粒的尺寸对返混也有影响,尤其是对非球形颗粒,尺寸越大,则Pe_L值越大。当气液两相流速不断增大时,床层中的流动状态从滴流区转变为脉动区,则液体性质对Pe_L值的影响也不同。给出了两个流区的Pe_L关联式。
In trickle-bed reactor packed with small spherical, cylindrical, and trilobe particles, the residence time distribution(RTD) curves of liquid phase were determined by tracer method for several kinds of gas-liquid systems at 303±1 K. The results show that the influeunce of properties of liquid on Peclet number is dependent on the hydrodynamic regime. The Peclet number increases during the transition from trickier-flow regime into pulse-flow regime. It also increases with size of packing except for spherical particles, in which the Peclet number slightly depends on the size. The non-spherical particles have lower Peclet number than that for spherical particles. The Peclet number was correlated by taking hydrodynamic flow regime into account:In trickle-flow regime:In pulse-flow regime:
关键词
固定床
滴流床
反应器
填料
返混
reactors
fixed bed reactor
catalyst
packing
back mixing
trickle bed
