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AssigneeBasell Polyolefine GmbH
InventorsGeorg Groos, Frank-Olaf Mähling, Andreas Daiss, Dieter Littmann, Kaspar Evertz
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In a process for preparing polyethylene in tube reactors with or without autoclaves, where a free-radical initiator is introduced with or without cold ethylene into a flowing ethylene- and comonomer-containing medium, rotation is generated between two streams (61, 62) to be mixed at an angle (66) or by provision of a swirl element (20, 80) in the flow cross section (27, 28). In the region of a feed point (72, 81) for a free-radical initiator, there is provided a cross-sectional constriction (63, 67, 71) at which the free-radical initiator is introduced through an optimized off-center outlet opening (44) of an introduction finger (40) into the rotating flow (61, 62, 70).
A process for preparing polyethylene in tube reactors and/or in combination with autoclaves, in which a free-radical initiator is introduced into a flowing medium comprising ethylene and possibly comonomers and which comprises at least the following steps:
An apparatus for preparing polyethylene in tube reactors, in which a free-radical initiator is fed into a flowing ethylene- and possibly comonomer-containing medium (61, 62) and the flowing medium (61, 62) passes through a reaction tube (1) having a changing flow cross section (27) and a free-radical initiator is introduced in a mixing region (13), wherein substreams (61, 62) of the flowing medium impinge on one another at an angle (66) or swirl elements (20, 80) are located in the flow cross section (27, 28) and a feed finger (40 having an off-center outlet orifice (44) for a free radical initiator is located downstream of a constriction (71) in the rotating flow (70).
Dependencies are inferred from the claim text.