TH8915B - Methods and equipment for removing gaseous, non-polymerized monomers from olefin polymers. - Google Patents

Abstract

The equipment for removing monomers from solid olefin polymers containing monomers consists of: a tapered removal vessel, where the height-to-diameter ratio is 0.5:1 to 10:1 and the walls taper at an axial angle of 0.5 to 15 degrees; a solid vent unit located at the bottom of the removal vessel; a solid receiving hopper; a solid inlet within the receiving hopper; a feed path within the receiving hopper connected to the inlet for feeding solids into the removal vessel; a gas-permeable, solid-impermeable confinement path located below the feed path, which defines an upper limit of the solid expansion bed and establishes a gas collection chamber between the top of the removal vessel and the confinement path; a gas inlet located within the removal vessel, inside or below the solid expansion bed; and a gas vent path connected to the gas collection chamber for venting gas from that chamber; and a process for removing non-polymerized monomers from the solid mixture, olefin polymer pellets, and gaseous monomers using the equipment.

Claims (7)

1. Equipment for removing unpolymerized monomers from olefin polymers containing monomers, consisting of: a tapered disposal vessel with a height-to-diameter ratio at the base of 0.5:1 to 10:1 and a wall taper angle of 0.5 to 15 degrees relative to the vertical axis; a solid vent unit located in the lower part of the disposal vessel; a solid receiving hopper; a solid inlet located in the receiving hopper; a feed method located in the receiving hopper connected to the inlet for feeding solids into the disposal vessel; a gas-permeable, solid-impermeable confinement pathway located below the feed pathway, defining an upper limit of the expanded solid bed and establishing a gas collection chamber between the top of the disposal vessel and the confinement pathway; a gas inlet located in the disposal vessel inside or below the expanded solid bed; and a gas vent path connected to the gas collection chamber for venting gases from the chamber. 2. The device of claim 1 here has a vertical angle of 3 to 10 degrees and a height-to-diameter ratio at the bottom of 1.5 to 1 to 8:1. 3. The device under claim 2 herein has a height-to-diameter ratio at the bottom of 1.5 to 1 to 3 to 1. 4. A procedure for removing non-polymerized gaseous monomers from a mixture of solid, olefin polymer beads, and the aforementioned gaseous monomers, consisting of countercurrent gas purification through the bed of the mixture in the apparatus of Patent 1, venting the purification gas and non-reactive gaseous monomers from the apparatus, and venting the olefin polymer beads from the aforementioned apparatus. 5. The process of claim 4 herein, polymers are (a) homopolymers of ethylene or propylene; (b) copolymers of the majority molar percentage (greater than 50%) of ethylene and a minority molar percentage of alpha-olefins containing one or more 3-8 carbon atoms; (c) copolymers of the majority molar percentage (greater than 50%) of propylene of one or more alpha-olefins containing one or more 4-8 carbon atoms; (d) polyvinyl chloride; (e) polybutadiene or polyisoprene; (f) "sticky polymers". 6. The process for claim 5 in this case, "Sticky Polymer" is selected from the group consisting of ethylene-propylene rubber and ethylene-propylene-diene rubber, propylene-ethylene block copolymer with high ethylene content, poly(1-butene), ethylene-butene rubber, terpolymer containing hexene-ethylene-propylene-ethylene-norbornene, and ethylene-propylene-hexadiene-terpolymer. 7. The procedure for claim 5, in this case the polymer is polybutadiene or polyocyprine.