Patent ID: 7683143

Claim:
A polymerization process comprising: (a) introducing a reaction medium into a polymerization reactor comprising a plurality of vertically-spaced sloped trays; (b) causing said reaction medium to flow downwardly in said polymerization reactor over said vertically-spaced trays, wherein the average thickness of said reaction medium flowing on said vertically-spaced trays is maintained at about 2.5 inches or more; and (c) withdrawing said reaction medium from said polymerization reactor, wherein the degree of polymerization (DP) of said reaction medium withdrawn from said polymerization reactor is at least about 25 percent greater than the DP of said reaction medium introduced into said polymerization reactor, and wherein said vertically-spaced trays include a plurality of uni-directional trays and at least a portion of said reaction medium simultaneously flows over two generally opposite ends of at least one of said uni-directional trays.