Abstract: A mold for molding articles of plastic or other like materials, having a plurality of vertically extending internal passages, is connected by inlet and return conduits into a closed loop that includes a heat exchanger partially filled with a liquid supply of a cooling fluid or a heating fluid. For cooling the heat exchanger is positioned with its liquid level above the top of the mold, the inlet conduit connects the lower part of the heat exchanger, below the liquid level, to the lower ends of the mold passages, and the return conduit connects the upper ends of the mold passages to the upper part of the heat exchanger; for heating these relationships are reversed. In operation the fluid changes its physical state at critical points in the mold passages, going from liquid to vapor for cooling and from vapor to liquid for heating; circulation in the closed loop is in response to the effect of gravity. Operation of the heat exchanger is controlled to maintain a controlled pressure in the closed loop.

Abstract: A mold for molding articles of plastic or other like materials, having a plurality of vertically extending internal passages, is connected by inlet and return conduits into a closed loop that includes a heat exchanger partially filled with a liquid supply of a cooling fluid or a heating fluid. For cooling the heat exchanger is positioned with its liquid level above the top of the mold, the inlet conduit connects the lower part of the heat exchanger, below the liquid level, to the lower ends of the mold passages, and the return conduit connects the upper ends of the mold passages to the upper part of the heat exchanger; for heating these relationships are reversed. In operation the fluid changes its physical state at critical points in the mold passages, going from liquid to vapor for cooling and from vapor to liquid for heating; circulation in the closed loop is in response to the effect of gravity. Operation of the heat exchanger is controlled to maintain a controlled pressure in the closed loop.

Abstract: This invention relates to apparatus for controlled cooling of an extruded plastic product. As the product exits the extrusion die, it passes through an elongated shell. The shell surrounds the die at its inner end and extends outwardly along the extrusion. A seal ring at the outer end of the shell engages the exterior of the extruded product; the shell, seal ring, and product define an annular cooling chamber through which a coolant is circulated through the cooling chamber, the coolant exiting through an annular cooling chamber extension in the die. For a hollow extruded product, the apparatus further includes an internal cooling tube that extends axially through the interior of the hollow product. The tube ends at a seal cap that engages the internal surface of the hollow product. The tube and seal cap define a second, internal cooling chamber through which coolant circulates; the coolant enters throught the end of the tube opposite the seal cap and exits through an annular recess in the die.

Abstract: A method and apparatus for maintaining a dehumidified atmosphere or other controlled atmosphere around the mold of a reciprocating-platen molding press, in which a sheet of light weight flexible material, preferably a transparent plastic film, is mounted on the platens, as by a plurality of permanent magnets, to form an open bottom tent enclosing both halves of the mold. For a dehumidified atmosphere, a dehumidifier generates a stream of warm dry air that is continuously discharged into the tent, from locations adjacent each platen, with a volume sufficient to maintain the tent inflated for all platen positions despite continuing air loss through the open bottom of the tent. The dehumidifier preferably uses a chilled water supply that is also employed to cool the molds in order to obtain automatic dew point correction. For other atmospheres, an appropriate source is substituted for the dehumidifier.

Abstract: A converter for connecting a second condenser in series in a process fluid chilling loop system including a compressor, a discharge service valve mounted on the compressor outlet, a condenser, and a refrigerant-to-process fluid heat exchanger. The converter includes a housing, mounted on the compressor interposed between the compressor outlet and the discharge service valve, which includes first and second separate transfer chambers. The first transfer chamber connects directly to the compressor discharge port and the second transfer chamber connects directly to the discharge service valve. Each transfer chamber is connected to an external port on the housing by a plurality of small tunnel passages, thereby affording a thin, flat converter for connecting a second condenser in series with the system. An inclined web that extends from an annular wall on one side of the housing to an annular wall on the other side of the housing divides the housing into the first and second separate transfer chambers.

Abstract: A control system for a water chiller comprising a heat exchanger, a pump for circulating a coolant comprising water or other process fluid through a path including the heat exchanger, a process apparatus, and a reservoir, and a compressor for circulating refrigerant through a path including the heat exchanger and a condenser; the control system includes electronic sensors for sensing the water supply pressure to the process apparatus, the refrigerant pressures at the compressor inlet and outlet, the water level in the reservoir, and the water temperatures at the heat exchanger inlet and outlet.

Abstract: A process liquid circulation and temperature control system including a pump for circulating water or other process liquid through a path including a heating unit, a cooling unit, and a process apparatus that is returned to the pump; the pump and the heating and cooling units are actuated in response to temperature/pressure variations sensed at the return from the process apparatus and at the delivery thereto. One pressure control measures the differential pressure across the pump and inhibits system operation except when the differential exceeds a predetermined magnitude in a given direction; another pressure control inhibits operation if the return pressure falls below a given threshold; a circuit that determines .DELTA.P/T prevents boiling of the process fluid. For both temperature and pressure controls, the delivery and return sensors are calibrated to match each other on system start-up.