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:
Jun. 12, 2012
Filed:
Dec. 17, 2008
Antonio Mazzucco, Ferrara, IT;
Riccardo Rinaldi, Mantova, IT;
Silvia Soffritti, Ferrara, IT;
Enrico Balestra, Ferrara, IT;
Giuseppe Penzo, Mantova, IT;
Gabriele Mei, Ferrara, IT;
Antonio Mazzucco, Ferrara, IT;
Riccardo Rinaldi, Mantova, IT;
Silvia Soffritti, Ferrara, IT;
Enrico Balestra, Ferrara, IT;
Giuseppe Penzo, Mantova, IT;
Gabriele Mei, Ferrara, IT;
Basell Poliolefine Italia, s.r.l., Milan, IT;
Abstract
A process for the gas-phase polymerization of α-olefins carried out in two interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, the process being characterized in that: (a) the gas mixture present in the riser is totally or partially prevented from entering the downcomer by introducing into the upper part of said downcomer a liquid stream LB having a composition different from the gaseous mixture present in the riser; (b) the ratio R between the flow rate Fof polymer circulated between said downcomer and said riser and the flow rate LB of said liquid being adjusted in a range from 10 to 50.