Plastic extruders are inseparable from chillers in the production of extruded pipes, trunkings, cables and various plastic profiles. The raw materials heated and melted are cooled by frozen water after being molded by the mold. The water temperature in the frozen water bath must be kept constant. Due to the high production speed, a chiller with large cooling capacity is required. If the existing freezing pool is large enough, the chiller may not be equipped with a water tank.