Low energy recovery compounding and fabricating systems for plastic materials

Claim 1

In a process for the production of polymer wherein a liquid polymer melt and entrained volatile monomer are delivered from a reactor to a product receiver for partial flashing of the volatile monomer the improvement comprising the steps of transferring the polymer from the bottom of said product receiver to the top of a vent stack; flashing the remaining volatile monomer from the melt in the vent stack; discharging said polymer melt from the bottom of the vent stack into the inlet of a gear pump having a pair of horizontal, intermeshing, rotating gears; directing the melt between said gears with the use of a pair of opposed cylindrical surfaces whose elements are parallel to the gear axes, said surfaces extending below the plane of the gear axes and each surface defining with its proximate gear axis a decreasing hydraulic radius toward the bottom pump discharge; discharging pressurized melt from the intermeshing gears through an outlet having a width corresponding to the gear width and a length corresponding to the tooth height of said gears, respectively, while providing a seal between each gear and the pump housing adjacent the outlet; sensing and maintaining the level of liquid in said stack to provide a pressure head above said gear pump.