Abstract:

Since the Ergun equation is applicable for calculation of gas-liquid pressure drop in the cases without interphase interaction, and the pressure drop ratio of single gas phase to gas-liquid concurrent flow can be accounted for as the relative permeability of the gas phase, the Ergun equation is proposed to characterize the flow regime transition based on the gas-liquid interaction in a trickle bed. To check the validity of this methodology, experimental work was conducted in a plexiglass column of 140 mm ID packed with glass beads of different diameters (1.9, 3.6, 5.2 and 9.3 mm) by applying air and water as the working media. The transient data under pulsing flow were obtained by applying pressure transducers and electrical capacitance tomography (ECT).The comparison of pressure drops from experiment and prediction showed that the Ergun equation was inappropriate to the pulsing flow, in which the gas-liquid interaction is significant. Therefore, the experimental two-phase pressure drop was used instead of the theoretical one for the calculation of gas relative permeability. It was found that the permeability of gas under various gas and liquid flow rates as well as different particle diameters was lower than 0.08 if pulsing flow was reached.

Key words:

涓流床, 电容层析成像, 持液量, 渗透率, 流型过渡

摘要：

由于Ergun方程可适用于气液间无相互作用的两相流动压降计算，并且由气相单相和气液两相并流下的气相压降比值可计算气相相对渗透率，因此，Ergun方程可用于涓流床中不同流区过渡和气液相互作用程度的表征。为检验这一方法的有效性，实验测定了空气-水体系在内径140 mm有机玻璃塔中不同粒径玻璃珠（1.9、3.6、5.2、9.3 mm）组成的床层压降和持液量。由于采用了压力传感器和电容层析成像仪，因此可测定脉冲流状态下的瞬态数据。通过压降的实验值与理论值比较，发现Ergun方程的适用范围有限，在没有进入脉冲流前先已失效，说明此时气液间作用已经相当显著。鉴于此，改用气液两相压降实验值代替理论值进行了气体渗透率的计算，发现不同气液流速和颗粒直径下出现脉冲流时的气体渗透率均低于0.08。

关键词:

涓流床, 电容层析成像, 持液量, 渗透率, 流型过渡