Patent ID: 7696288
Filing Date: 2010-04-13
Classification: B01J,C08F

Abstract:
1. A method for the polymerization of an olefin monomer in a loop reactor system comprising: a) introducing an olefin monomer and a diluent carrier liquid into a reactor system comprising at least one loop reactor; b) supplying at least one polymerization catalyst system to said reactor system; c) circulating said diluent liquid and olefin monomer through said loop reactor while polymerizing said olefin monomer in the presence of said catalyst system to produce a slurry of polymer fluff particles in said diluent carrier liquid; d) diverting the flow of said slurry through said loop reactor into a plurality of settling legs which are connected to said loop reactor and each of which are provided with an outlet valve which is repeatedly triggered to open said outlet valve to discharge settled polymer slurry from said settling leg and thereafter closed to allow polymer slurry to accumulate in said settling leg; and e) controlling the triggering of said outlet valves to provide an aggregate time of discharge from said plurality of settling legs which is more than 50 percent of the time interval between successive sequential triggerings of said outlet to allow for the discharge of slurry from said settling leg.