PETpla.net Insider 06 / 2015

PREFORM PRODUCTION 25 PET planet insider Vol. 16 No. 06/15 www.petpla.net Adiabatic cooling towers cut energy consumption EarthSmart adiabatic cooling towers from Conair can reduce water and energy consumption and prevent contamination of process f uid, while maintaining stable leaving f uid temperatures even in hot weather Plastics processors who use EarthSmart adiabatic cooling towers of Conair can 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 as little as 170 l/ min (45 gal/min) up to 1,930 l/ min (510 gal/min) of process fluid (35% ethylene glycol). Lower process water temperature than conventional tower The adiabatic part of the system is what reduces the temperature of the air flowing through the tower. The evaporation of moisture from the adi- abatic pads causes it to cool the air so that it can remove heat from the process water circulating through coils in the tower. The cooled air allows the tower to achieve a lower pro- cess water temperature than can be reached with only ambient air flowing through conventional towers. In addi- tion, the adiabatic design saves water and energy by keeping the process fluid separate from the water evapo- rated during the adiabatic process. Cooling tower can be operated with or without using adiabatic process 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 tem- perature 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 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 mould-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. PLC precisely controls when the adiabatic process is required An application-specific program- mable logic controller (PLC) and elec- tronically commutated (EC) motors, standard on the EarthSmart towers, ensure minimal electrical power is used during the process. Smart-fan technology varies speed to minimise energy consumption when the tower is under partial load. The PLC also precisely controls when the adiaba- tic process is required to maintain accurate leaving fluid temperature and reducing water use. Further features 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 lifes- pan of the coil. www.conairgroup.com