Full Tower Efficiency of small air separation unit

We calculate the number of plates assuming that the liquid and vapour on each plate are interacting to reach equilibrium. In practice, it is not possible to achieve an ideal equilibrium for all plates in a nitrogen distillation column, so the actual number of plates required is greater than the theoretical number of plates required. The ratio of the theoretical to the actual number of plates is the full tower efficiency. Factors affecting the full tower efficiency are: the gas phase and liquid phase mass exchange, the tower plate on the degree of gas, liquid mixture and steam into the last tower plate when the number of mist entrainment.