Patent ID: 8636138

Claim:
A polymer finishing process comprising: recovering a polymer powder from a polymerization reactor; feeding the polymer powder to an inlet end of a mass flow screw conveyor, the mass flow screw conveyor comprising: a housing; at least one helical auger at least partially contained within the housing for conveying the polymer powder axially through the mass flow screw conveyor; and one or more mass measuring devices for determining a mass of polymer powder within at least a portion of the housing; rotating the at least one helical auger to convey the polymer powder axially through the screw conveyor; recovering the polymer powder at an outlet end of the screw conveyor; measuring at least one of a mass of the polymer powder in the screw conveyor and a combined mass of the screw conveyor and the polymer powder within the screw conveyor with the one or more mass measuring devices; determining a mass flow rate of the polymer powder through the mass flow screw conveyor based on the at least one of the measured mass of the polymer powder in the mass flow screw conveyor and the measured combined mass; and feeding at least one additive to the mass flow screw conveyor intermediate an inlet end and an outlet end of the mass flow screw conveyor; measuring a mass of the polymer and the at least one additive within the outlet end of the mass flow screw conveyor using a second mass measuring device.