Abstract: A method for controlling a transition from an initial polymerization reaction to a target polymerization reaction in a manner that reduces significantly the amount of off-grade product having excessively low density produced during the transition, including steps of: during the transition, maintaining a first one of a concentration ratio and a feed ratio at an at least substantially constant value while implementing process changes in an effort to bring produced polymer into compliance with a target specification set and monitoring (without controlling) the other one of the concentration ratio and the feed ratio to generate first data; and during the transition, determining from the first data whether polymer having excessively low density is likely to be produced during the transition, and upon determining that polymer having excessively low density is likely to be produced during the transition, maintaining during the remaining portion of the transition the other ratio at a value that is at least substantia

Abstract: A nozzle for catalyst injection for olefin polymerization is provided. In one or more embodiments the nozzle includes a first conduit including a body, a tapered section, and an injection tip. The nozzle also includes a second conduit having an inner surface and an outer surface. The first conduit is disposed about the second conduit defining a first annulus therebetween. The nozzle further includes a support member at least partially disposed about the outer surface of the first conduit defining a second annulus therebetween. The support member has a converging outer surface at a first end thereof.

Abstract: Disclosed herein is a gas phase polymerization process including the steps of passing a recycle stream through a fluidized bed in a gas phase fluidized bed reactor in the presence of a bulk density promoting agent, wherein the bulk density promoting agent is of a saturated hydrocarbon and/or a non-polymerizable unsaturated hydrocarbon having 6 or more carbon atoms; polymerizing at least one alpha-olefin monomer in the presence of a catalyst to produce an alpha-olefin polymer; and controlling an amount of the bulk density promoting agent in the reactor such that a bulk density of the alpha-olefin polymer discharged from the reactor is greater than or equal to about 480 kg/m3.