低、高压滴流床中压降和持液量计算的统一关系式

CORRELATIONS FOR PREDICTION OF PRESSURE DROP AND LIQUID HOLDUP IN LOW AND HIGH PRESSURES TRICKLE BEDS

基于对滴流床中气液两相流动特征尺度的分析 ,提出以修正的相摩擦系数对相Reynolds数进行关联 ,获取低、高压滴流床中压降和持液量计算的统一关联式的方法 .对于滴流床中单相不饱和流 (液体流动 ,气体静止 )情形 ,以及低压和高压滴流床中两相流、高气液作用情形 ,收集了文献报道的不同大小颗粒、不同物系的大量实验数据 ,以相摩擦系数对相Reynolds数进行关联 ,得到新的压降和持液量计算式 ,其物理意义明确 ,计算精度得以提高 .

Based on an analysis of the Ergun equation used for single phase flow in a packed bed, characteristic scales of flow are established for an equivalent representation of gas-liquid two phase flows in low and high pressures trickle beds. In terms of the scales and using available data by different authors, new improved correlations for evaluation of two phase pressure drop and phase holdups are proposed for porous and non-porous packings with equivalent diameters of 1.5-6 mm, and for modified Reynolds number from 3.3 to 88, operation pressures up to 6 MPa and superficial gas velocities up to 8.8 cm&middots-1. The evaluation gives a mean relative deviation 35.8% for the two phase pressure drop, and a mean relative deviation 11.2% for liquid holdup.