Abstract: A gas distributor plate provided in a fluidized bed polymerization vessel which effects the gas phase polymerization of olefins, the gas distributor plate exhibiting excellent action for uniformly diffusing the gas flow in the fluidized bed zone. A gas distributor plate has a number of gas passage holes and is provided in a fluidized bed polymerization vessel which effects the gas phase polymerization of olefins, wherein when the inner radius of the straight drum portion of the polymerization vessel is denoted by 1, the holes perforated in the outer peripheral portion of the distributor plate at 0.7 to 1.0 from the center of the straight drum portion have an average diameter which is larger than the average diameter of the holes perforated in the inner peripheral portion of the distributor plate at smaller than 0.7 from said center.

Abstract: Disclosed is a drying hopper comprising, disposed in its lower position, a cone portion having diameters gradually decreasing toward a lower end thereof, in which a high temperature gas is injected toward powder descending in the cone portion to thereby dry the powder, wherein said drying hopper comprises a cone portion 11 having a slant, circular wall, said cone portion 11 having a plurality of vertically spaced rows of nozzles 20, formed through the circular wall, disposed at predetermined intervals in a circumferential direction of the circular wall; a plurality of vertically spaced ring-like shells 21 fluidtightly attached to an external surface of the circular wall of the cone portion 11 with interstices therebetween in positions such that said plurality of rows of nozzles 20 are respectively, at gas inlets thereof, covered by said plurality of ring-like shells 21; and a plurality of gas feed pipes 22 respectively connected to said plurality of ring-like shells 21 in communicating relationship.

Abstract: Disclosed is a drying hopper comprising, disposed in its lower position, a cone portion having diameters gradually decreasing toward a lower end thereof, in which a high temperature gas is injected toward powder descending in the cone portion to thereby dry the powder, wherein said drying hopper comprises a cone portion 11 having a slant, circular wall, said cone portion 11 having a plurality of vertically spaced rows of nozzles 20, formed through the circular wall, disposed at predetermined intervals in a circumferential direction of the circular wall; a plurality of vertically spaced ring-like shells 21 fluidtightly attached to an external surface of the circular wall of the cone portion 11 with interstices therebetween in positions such that said plurality of rows of nozzles 20 are respectively, at gas inlets thereof, covered by said plurality of ring-like shells 21; and a plurality of gas feed pipes 22 respectively connected to said plurality of ring-like shells 21 in communicating relationship.