Hindustan Zinc uses cooling towers at its smelter to manage waste heat. Induced-draught cooling towers had been in use to cut back the temperature of hot streams from the assorted operations in the plant with the evaporation of the water used to remove process heat and to cool the working fluid. This frequent process, seen at most energy stations, resulted in significant water consumption within the form of evaporation, so Hindustan Zinc sought a special, extra environmentally-pleasant solution.
Hindustan Zinc installed its first adiabatic cooling towers (ACTs) to substitute the conventional cooling towers. An adiabatic cooling tower operates as an air-cooled heat exchanger, rejecting heat from a process cooling medium to the encompassing environment by means of both dry cooling (convective heat transfer) or wet cooling (a double convection cycle between water and air), during which water acts because the cooling medium for wetting the air and the cool air in flip cools the hot process water. ACTs reduce water wastage by nearly 80% by operating in a closed circuit.