The WFI Still work on the distillation principle.
The first column is heated by the external Plant steam. The generated vapor by the feed water rises up the column where it is subjected to the entrainment separation system.
Multidirectional baffles deliver the first punch. The steam generated from the first column is made to pass a torturous path through multidirectional baffles. Here the pyrogen particles and droplets separate and are guided to the end of the column.
A centrifugal type cyclone separator high up in the column delivers the second punch. Here the vapor is guided through a narrow circular channel where it begins to rotate.
The vapor flow subjects the pyrogenic impurities and droplets to a high centrifugal force thereby dislodging them from the vapor steam. The distillation units are connected in series into a multiple effect system and external energy is required only at the first column. The steam generated in each column is supplied to the subsequent column.
The generated steam vapor of the last column and the almost condensed steam distillate (2nd column onward) is led to the over head cooling heat exchanger, where it is cooled by the cooling water & incoming feed water to generate WFI.