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:
Jan. 10, 2012
Filed:
Oct. 18, 2005
John R. Parrish, Cross Lanes, WV (US);
Paul K. Samples, Scott Depot, WV (US);
Ivan J. Hartley, Victoria, TX (US);
Jeffrey Brian Drabish, Elkview, WV (US);
John R. Parrish, Cross Lanes, WV (US);
Paul K. Samples, Scott Depot, WV (US);
Ivan J. Hartley, Victoria, TX (US);
Jeffrey Brian Drabish, Elkview, WV (US);
Dow Global Technologies LLC, Midland, MI (US);
Abstract
Embodiments of the invention provide a method of controlling a gas-phase polymerization process. The method includes determining a difference between a control variable of the polymerization process, such as the production rate, and the desired value of the control variable; adjusting or maintaining a first manipulated variable to at least partially compensate for the difference between the control variable and the desired value; and adjusting or maintaining a second manipulated variable to at least partially compensate for the effect of adjusting or maintaining the first manipulated variable. The first and second manipulated variables can include process variables such as the fluidized bed weight, the catalyst concentration, the concentration of one or more monomers, the flow of one or more comonomers, the ratio of one comonomer to another comonomer, the activator concentration, the ratio of an activator to selectivity control agent, the concentration of a chain transfer agent, and the retardant concentration.