Question

what is vapor disengagement in distillation

Answer 1

The term Vapour disengagement term is used for typical gas liquid operations like Distillation,Absorption,stripping,etc. In distillation,this is normally used in context of Plate type column,So what happens when the vapour contacts with the liquid on any tray,then because of its high flow rate it tries to carry the liquid droplet because of entrainment to other tray.The disadvantage of of this phenomenon is that since vapour is rich in more volatile component while liquid is rich in less volatile component,then it is highly possible that less volatile liquid again reaches to top plate because of vapour and hence,it reduces the efficiency of separation process.So in order to overcome this i.e. to avoid the entrainment of liquid droplet in vapour ,sufficient space is provided above the tray or plate to separate liquid droplet from column.That's why a downcomer is also used.This downcomer has two functions, first moving liquid from one contacting tray to another and second disengaging vapour from liquid.So Vapour disengagement is basically the separation of entrained liquid droplets from vapour in the space provided between two trays.