公开(公告)号：US12065518B2

公开(公告)日：2024-08-20

申请号：US17309175

申请日：2019-11-13

Applicant: ExxonMobil Chemical Patents Inc.

Inventor： Paul J. Clymans ,  Jefferson P. Galliano ,  Philippe A. P. D'Hooghe ,  Cindy Dewitte ,  Henri A. Lammens

IPC: C08F2/01 ,  B01J3/04 ,  B01J19/00 ,  C08F110/02 ,  C08F210/02 ,  C08F218/08

CPC classification number: C08F2/01 ,  B01J3/042 ,  B01J19/002 ,  C08F110/02 ,  B01J2219/00162 ,  B01J2219/00236 ,  B01J2219/00259 ,  B01J2219/0027 ,  C08F218/08 ,  C08F2400/04

Abstract: Controlling the shutdown of a polyethylene reactor system that includes a secondary compressor, a reactor, a high pressure let down valve (HPLDV), a high-pressure separator, and a high-pressure recycle gas system is provided. After a partial or complete shutdown of secondary compressor, HPLDV opens to a pre-set open position until the reactor pressure reduces to either a pre-set reduced pressure limit or a until the slope of the reactor gas density to reactor pressure exceeds 0.15. The HPLDV controls the pressure to a pressure set point.