The distillation column is the heart of a multiple-effect water still.
Its design determines how the unit operates.

The distillation column incorporates a unique double punch pyrogen
seperation system. The first punch is delivered by impact type multi- directional baffles. The generated vapour flows a torturous path through multi-direction baffles where pyrogens, particles and droplets seperate out and are guided to the bottom of the column. The second punch is delivered by a centrifugal type cyclone seperator higher-up in the column. Here the vapour is guided through a narrow, circular channel where it starts to rotate. The vapour flow subjects pyrogens impurities and droplets to a high centrifugal force, thereby dislodging them from the vapour stream. The distillation columns are connected in series into a multiple-effect system, and only the first column is heated by a external
energy source.
The pure vapour generated in the first column is used us a heating source for the next column. On condensation is led to the distillate piping. Feed water from the first column is fed by a unique differential pressure gradient to the subsequent columns.
Pure vapour generated from the last column and almost condensed distillate from all other columns is led to the common cooler mounted on top of the equipment. In the cooler the distillate is cooled by feed water During the cooling effect feed-water is pre- heated to a temperature of 95 Deg.C. before it reaches the first column. In a Multiple-Effect Distillation Unit the amount of cooling water required is very small because most of the heat has already been utilized during previous process stages for pre-heating water.

The common cooler of the still has another important function: to seperate gases from the distillate. This is essential for the quality and conductivity of the distillate.

This multiple effect design is an economic method of manufacturing distilled water due to low staem and cooling water consumption. Withh a 6 effect still both steam and cooling consumptions are 50% and 90% respectively when compared to a 3 effect still.

Distillation Column
The column is fabricated from S.S. 316 or S.S. 316L and as per guidelines of ASME Section VIII. The column houses the heat exchanger and the pyrogen sepration systems. The heat exchangers have special FLOATING desing to eliminate danger of tube cracking due to thermal stresses induced by cyclic expansion and contraction, a problem quite common in heat exchangers with rigidly held tube sheets. Optionally double-tube- sheet type heat exchangers can be provided.

High quality is ensured by first-class raw material and controlled argon welding techniques.

Common Cooler
At the end of the distillation process there is a condenser which condenses the steam and seperates the gases from the distillate produced. When designing the condenser, we took into account the current GMP requirements and all the factor affecting the gas seperation. The Feed-Water and Cooling-Water coils are helixs manufactured from a single S.S. 316 or S.S. 316L tube and meets all the standard requirements of the pharmaceutical industry by a wide margin.

Instrument and Control System
All distillation units are controlled by a reliable system thereby reducing mal-function and resultant shut downs. All the process valves used are pneumatically operated including the three-way valve at the distilled water outlet. This three-way valve is automatically controlled to dump distilled water in case of sub-standard quality. Monitoring conductivity of distilled water is an important factor of all distillation units.

The feed water control system prevents sub-standard feed-water from entering the unit.