Abstract: An improved method for polymerizing one or more polyolefins in the presence of a transition metal catalyst in at least one gas phase reactor having an expanded section, the improvement comprising generating a tangential flow of gas or gas-solids in the expanded section of the gas phase reactor to reduce fines entrainment into the gas cycle system and to reduce or remove solid particle build-up on one or more interior surfaces of the expanded section of the reactor.

Abstract: A method for removing unpolymerized gaseous monomers from a solid olefin polymer in a single purge vessel while deactivating Ziegler-Natta catalysts and organometallic catalyst residues present in said solid olefin polymer by utilizing a two diameter purge vessel wherein hydrolysis of the catalysts are effected in the portion of the reactor having the smaller diameter with the gaseous monomers being removed in the larger diameter portion.

Abstract: A degassing or purging process is disclosed for the removal of unpolymerized gaseous monomers from solid olefin polymers. The disclosed process comprises conveying the solid polymer, e.g. in granular form, to the top of a purge vessel by means of an inert gas stream, feeding an inert gas stream to the bottom of the purge vessel and countercurrently contacting the solid polymer with the inert gas purge stream to strip away the gaseous monomers evolved from the solid polymer, and recycling a portion of the resulting stream to the purge vessel. In one embodiment, the recycle serves as the conveying gas and in another embodiment as the purge stream. The process is especially useful in purging gaseous unpolymerized hydrocarbon monomers from low pressure-polymerized, low density ethylene-hydrocarbon copolymers.