Heat exchanger apparatus for extruding thermoplastic compositions

摘要

Disclosed is heat exchange apparatus for controlling the temperature of a resin after leaving an extruder and prior to extrusion through a die in an extrusion process, comprising a heat exchanger having an inlet and outlet for an extruded heat-plastified resin and an inlet and an outlet for a heat exchange medium to be circulated in heat exchanging relationship with the extruded resin; a selective heater for receiving the heat exchange medium from the heat exchanger, the heater heating the heat exchange medium to a predetermined temperature during a start-up phase of the heat exchange device; a cooler adapted for receiving a portion of the heat exchange medium from the heater, the cooler including an inlet and an outlet for the heat exchange medium and an inlet and an outlet for a cooling medium to be circulated in heat exchanging relationship with the heat exchange medium; control means interposed between the heater and the cooler for selectively directing a portion of the heat exchange medium to said cooler in response to a sensed temperature condition and for directing the balance of the heat exchange medium to the heat exchanger; and a pump for circulating the heat exchange medium between the heat exchanger, the heater, and the cooler.