以多孔的球、齿球和三叶草形催化剂为填充颗粒，考察了微膨胀床反应器的床层压降及液相总的和局部的轴向扩散特性。结果表明，3种催化剂床层压降都随表观液速的增大而增大，随表观气速的增大而减小；球形催化剂的床层压降最大，三叶草形催化剂的床层压降最小。通过示踪-响应法测定示踪剂在微膨胀床反应器中的停留时间分布，求取了床层总的和局部的彼克列数Pe。结果表明，3种催化剂总的彼克列数都随表观液速的增大而增大，随表观气速的增大而减小；局部的彼克列数随着催化剂床层轴向高度的增加而减小。3种催化剂床层的总的彼克列数大小依次为：球形最大，齿球形次之，三叶草形最小。

The total and local axial liquid dispersion, and the bed pressure drop, of a slightly expanded bed reactor have been investigated for catalyst beds packed with spherical, toothed-ball and cloverleaf catalyst particles. The values of total Peclet number and local Peclet number were determined by measuring residence time distributions using the tracer pulse-response method. The results indicate that, for all three kinds of catalysts, the values of total Peclet number increase with increasing superficial liquid velocity and decrease with increasing superficial gas velocity, and the values of local Peclet number decrease with increasing axial distance. Under the same operating conditions, the values of total Peclet number for the spheres are bigger than those for the toothed-balls, and the values of total Peclet number for the toothed-balls are bigger than those for the cloverleaf particles. The pressure drop increases with increasing superficial liquid velocity and decreases with increasing superficial gas velocity for all three catalysts. The pressure drop is largest for the spheres and lowest for cloverleaf particles.