滴流床反应器的脉冲特性

滴流床中气液流速较高时会产生脉冲流。脉冲特性可表示为：脉冲频率、脉冲速度、脉冲持液与脉冲间持液。这些参数可用气液流速、填料特性及气液物性来度量。在宏观物料衡算基础上推得脉冲速度的模型。脉冲持液就是反应器的动持液；脉冲持液与脉冲间持液之比近于1．5。发现脉冲频率完全受表观液速与临界液速的差值所控制。获得了三个关联式，涉及不同系统，也包含文献数据。

THE CHARACTERISTICS OF PULSING FLOW IN TRICKLE BED REACTORS

Pulsing flow occurs at high gas and liquid flow rates in trickle-bed reac- tors.The properties of pulses pulse frequency(pulse veloeity,liquid holdup in pulses and liquid holdup outside the pulses)were determined.These pa- rameters were measured as functions of gas and liqid flow rate,packing characteristics and physical properties of gas and liquid.Based on macros- copic mass balances,a model is developed to characterize the pulse velocity. Liquid holdup in pulses is the dynamic liquid holdup of the rectors.The ratio between the liquid holdup in pulses and the liquid holdup outside the pulses is found to be nearly constant at a value of 1.5.It was found that the pulse frequency is completely governed by the liquid flow in excess of a cri- tical liquid flow.Three relationships were worked out and correlated for dif- firent systems,data from the literatures were also included.