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:
May. 22, 1990
Filed:
Nov. 13, 1989
Gaylon L Dighton, Baton Rouge, LA (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
The invention is an apparatus and method for draining a viscous material, such as a molten polymer, from a vessel that contains the material. A ram-type valve is mounted on the outside of the vessel in line with a drain opening in the vessel. The valve is enclosed in a removable housing mounted on the outside of the vessel. During a process run, the valve piston closes off the drain opening, and an inert atmosphere inside the housing prevents oxygen from forming polymer 'gels' that can plug the drain opening. When it becomes necessary to drain the vessel, a remote control valve actuator moves the valve piston out of the drain opening, so the polymer can flow out of the vessel.