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:
Nov. 18, 2008
Filed:
Apr. 29, 2003
Peter Tell, Akersberga, SE;
Peter Tell, Akersberga, SE;
PIAB AB, Taby, SE;
Abstract
According to the invention, a vacuum pump is disclosed comprising a screw-rotor pump having a compression section () and an expansion section (), and wherein a discharge () from the compression section communicates with at least one ejector () for discharge of compressed gas through the ejector, and wherein the expansion section () is connectable via a first valve means (), to a drive-gas source (P) for operating the screw,-rotor pump and the ejector in parallel. Also, a method for providing sub-pressure to an industrial process is disclosed wherein at least one ejector () is used initially to reduce the pressure to a predetermined lower level, from where the pressure is further reduced by means of a screw-rotor pump () that is arranged to operate through, and in parallel with the ejector.