Processors that use EarthSmart Adiabatic Cooling Towers from Conair, Cranberry Township, Pa., can reportedly reduce water and energy consumption and prevent contamination of process fluid, while maintaining stable leaving fluid temperatures even in hot weather. Process fluid circulates in a closed loop through tubing in the tower, so it is isolated from contamination and evaporation. Eleven models are available to handle nominal flow rates from 45 gal/min (170 l/min) up to 510 gal/min (1930 l/min) of process fluid (35% ethylene glycol).
Adiabatic wetted panels are mounted so that they are in front of the cooling tower coil through which process water flows. As ambient air passes through the wetted panels, water evaporates, reducing the temperature of the air flowing into the unit so that it cools the process fluid. The cooling towers can be operated without using the adiabatic process (relying on ambient air to cool the coils) when air temperatures are low. This saves water and energy. By only using the adiabatic process only when it is absolutely required during periods when outdoor temperatures are high, the unit reduces water consumption to just a fraction of what conventional towers use.
The process circuit is a closed-loop. All of the evaporation and water consumed in the adiabatic process is external to the process loop, so process-fluid contamination—and unwanted build-up in mold-cooling channels – is eliminated. The closed-process loop also allows an ethylene-glycol mix to be used in place of water, which helps prevent freezing during cold weather.
An application-specific programmable logic controller (PLC) and electronically commutated (EC) motors—standard on the EarthSmart towers—ensure minimal electrical power is used during the process. Smart-fan technology varies speed to minimize energy consumption when the tower is under partial load. The PLC also precisely controls when the adiabatic process is required to maintain accurate leaving fluid temperature and reducing water use.
Other features that are said to contributing to stress-free maintenance include:
- Motor-repair switches that allow individual fans to be shut down for service while other fans continue to operate.
- The adiabatic wetted panels that slide out easily for cleaning with no special tools required.
- EarthSmart tower coils that are supported independently of the frame allow for natural expansion and contraction, which eliminates wear points and extends the lifespan of the coil.
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