Apparatus and method for producing ethylene polymer

An apparatus for producing ethylene polymer which comprises:

• a conduit means for defining a flow passageway therethrough so as to form a closed loop, wherein at least a portion of said conduit means comprises at least one pipe, having an exterior surface, constructed of rolled plate which has two edges joined along a seam, and wherein said rolled plate comprises a steel which comprises less than about 0.5 weight percent carbon, less than about 1.5 weight percent manganese, less than about 1.0 weight percent silicon, less than about 2.5 weight percent chromium, and less than about 1.0 weight percent nickel;
• a cooling means for passing a flow of coolant fluid in heat exchange relationship with the exterior surface of said at least one pipe;
• a means for introducing at least one monomer which includes ethylene into said passageway;
• a means for introducing a polymerization catalyst and diluent into said passageway;
• a means for establishing a flow of said at least one monomer, catalyst and diluent in admixture through said passageway and around said closed loop, whereby said ethylene polymer is produced in said passageway;
• and
• a means for withdrawing polymer from said passageway.

A method of producing ethylene polymer which comprises:

• (a) providing a conduit means which defines a flow passageway therethrough so as to form a closed loop, wherein at least a portion of said conduit means comprises at least one pipe, having an exterior surface, constructed of rolled plate which has two edges joined along a seam;
• (b) introducing at least one monomer which includes ethylene into said passageway;
• (c) introducing a polymerization catalyst and diluent into said passageway;
• (d) establishing a flow of said at least one monomer, said catalyst and said diluent in admixture through said passageway and around said closed loop to thereby produce ethylene polymer in said passageway;
• (e) passing a flow of coolant fluid, during step (d), in heat exchange relationship with the exterior surface of said at least one pipe of said conduit means;
• and
• (f) withdrawing polymer from said passageway.

A method of producing ethylene polymer which comprises:

• (a) providing a conduit means which defines a flow passageway therethrough so as to form a closed loop, wherein at least a portion of said conduit means comprises at least one pipe, having an exterior surface, constructed of rolled plate which has two edges joined along a seam, and wherein said rolled plate comprises a steel which comprises less than about 0.5 weight percent carbon, less than about 1.5 weight percent manganese, less than about 1.0 weight percent silicon, less than about 2.5 weight percent chromium, and less than about 1.0 weight percent nickel;
• (b) introducing at least one monomer which includes ethylene into said passageway;
• (c) introducing a polymerization catalyst and diluent into said passageway;
• (d) establishing a flow of said at least one monomer, said catalyst and said diluent in admixture through said passageway and around said closed loop to thereby produce ethylene polymer in said passageway;
• (e) passing a flow of coolant fluid, during step (d), in heat exchange relationship with the exterior surface of said at least one pipe of said conduit means;
• and
• (g) withdrawing polymer from said passageway.