Principle of operation
Closed-Circuit cooling towers or fluid coolers operate just like the open type,
but dissipate the process fluid heat load into the ambient air via a closed-circuit heat exchanger.
This isolates the process fluid from the outside air, keeping it clean and free of contamination in a closed loop and creating 2 separate fluid circuits:
• An external circuit, in which spray water circulates over the closed-circuit heat exchanger and mixes with the outside air.
• An internal circuit, in which the process fluid circulates inside the closed-circuit heat exchanger. During the evaporative cooling operation, heat goes from the internal circuit, via the closed-circuit heat exchanger to the spray water, and then to the open air as a portion of the evaporating water