The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 06, 2021
Filed:
Nov. 09, 2017
Basell Polyolefine Gmbh, Wesseling, DE;
Gerhardus Meier, Frankfurt am Main, DE;
Ulf Schueller, Weiterstadt, DE;
Gabriele Mei, Ferrara, IT;
Massimo Covezzi, Ferrara, IT;
Pietro Baita, Ferrara, IT;
Lorella Marturano, Ferrara, IT;
Basell Polyolefine GmbH, Wesseling, DE;
Abstract
A process for preparing an ethylene polymer including the step of homopolymerizing ethylene or copolymerizing ethylene with one or more comonomers in a gas-phase polymerization reactor including a riser unit wherein growing polymer particles flow upwards under fluidization, fast fluidization or transport conditions and a downcomer wherein growing polymer particles flow downward in a densified form, wherein the hold-up of polymer particles in the downcomer is from 55 wt. % to 80 wt. % of the total hold-up of polymer particles in the gas-phase polymerization reactor.