两液相蒸馏系统筛型塔板的流动工况及其转变

Flow Regime Transition on Sieve Trays in a Distillation System Containing Two Liguid Phases

以空气和油、水混合物为介质，在冷模塔内进行筛板上气、液、液三相流动的操作工况及其转变的研究。着重考察筛板上存在两个液相的气液接触状况，实验测定雾沫夹带率和板压降的变化规律，并以雾沫夹带率及板压降变化的转折点作为三相流动工况的转变点，以此作为筛板的操作工况转变的判据。提出两液蒸馏的筛板流动工况转变点的雾沫夹带率及板压降的计算式。

The experiments were conducted in a distillation column simulator with sieve trays by using air and mixtures of liguid paraffine and water. The entrainment rate and the pressure drop of the system were measured. The transition of flow regimes on the trays was correlated with the inflection points of the entrainment rate or the pressure drop, the spray to mixed regimes transition was also measured by using γ-ray absorption technique. The entrainment rate or the pressure drop at the transition increases when one of the following increases: gas velocity, paraffine-water ratio, hole diameter at same hole velocity. Spray regime exists when liguid rate is low and gas velocity is high, and mixed regime occurs at comparatively low gas velocity and high liguid rate. Correlations are proposed for calculating the entrainment rate and the pressure drop at the transition which allow for the presence of two liquid phases.