Patent ID: 6350054
Filing Date: 2002-02-26
Classification: B01F,B01J

Abstract:
Apparatus for mechanically-stirring polymer particles in a vapor-phase polymerization system having at least one horizontally disposed cylindrical polymerization reactor containing subfluidized particulate polymer bed wherein at least a portion of the heat of polymerization is removed by evaporative cooling using a readily volatilizable quench liquid, comprising:a drive shaft being coaxially mounted for rotation about its longitudinal axis and predominantly within a substantially horizontal cylindrical polymerization reactor having a cylindrical reactor wall and inner diameter; one or more classes or substantially contiguous paddle stations disposed along the drive shaft within the reactor, each station having one or more station paddles attached to the shaft so as to sweep through a cylindrical zone within the reactor thereby defining station lengths along the shaft; and a plurality of sub-stations in at least one of said paddle station classes, each sub-station having lengths along the shaft of no more than 50 percent of total width of the paddle station, and one or more sub-station paddles attached to said drive shaft at each sub-station so as to sweep through a sub-section of the cylindrical zone within the reactor, said one or more substation paddles being disposed in one or more planes including said axis of said drive shaft.