A chiller is a heat-transfer device that uses mechanical refrigeration to remove heat from a process load and transfers the heat to the environment. Chillers are used by plastics processors when they need a lower process fluid temperature than a simpler system, such as an evaporative cooling tower, can provide.
Chillers are designed to ensure a continuous flow of coolant to the cold side of a process water system at a desired “leaving water temperature” or LWT of about 50°F (10°C). The coolant is then pumped through the process, extracting heat out of molds and machinery as it flows back to the return side of the process water system. The coolant flow, now at an elevated “entering water temperature” or EWT (5 to 10 degrees warmer than LWT), then re-enters the chiller, which does three things: