At present

studies on the sieve tray tower

one of the oldest towers

are widely carried out. An especially complicated one is on the structures of a sieve tray tower at different bubbles layers and the discrimination between regimes on the tower. This study is limited to direct and qualitative description. Comparatively

the study on the spray regime transferring principles is even weaker. This paper is baaed on the force equilibrium. In the paper

the effect of the local area void fraction in the liquid - gas mixture layer on a sieve bay is considered and the calculation model is developed. The comparision between experimental and the calculation results shows that the model is applicable to practical engineering design.