A mathematical model for predicting tray efficiency of a new vertical sieve tray tower was proposed, considering the characteristics of the gas-liquid cocurrent up-flow in the caps and the liquid mixing between the caps on the tray. The behavior of the tray was represented by a model of dual cell, a mass transfer cell and a liquid mixing cell.

The some cases of retrofitting valve tray, bubble cap tray, sieve tray and Rasching ring packing tower with the new vertical sieve tray tower  in polyvinyl chloride, chemical fertilizer and pharmaceutical plant are introduced in this paper. Looking to the future of NewVST in our national industry.