Vacuum pump and method for generating sub-pressure
AssigneePiab AB
InventorPeter Tell
Life of this patent
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Abstract
According to the invention, a vacuum pump is disclosed comprising a screw-rotor pump having a compression section (8) and an expansion section (7), and wherein a discharge (10) from the compression section communicates with at least one ejector (1) for discharge of compressed gas through the ejector, and wherein the expansion section (7) is connectable via a first valve means (5), 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 (1) 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 (7, 8) that is arranged to operate through, and in parallel with the ejector.
Claims8
A vacuum pump comprising a screw-rotor pump having a compression section (8) and an expansion section (7), characterized in that a discharge (10) from the compression section communicates with at least one ejector (1) for discharge of compressed gas through the ejector, wherein the expansion section (7) is connectable, via a first valve means (5), to a drive-gas source (P) for operating the screw-rotor pump and the ejector in parallel, and wherein a second valve means is arranged to close an evacuation passage (4) to the ejector, when said first valve means is open for driving the screw-rotor pump.
Method of providing sub-pressure to an industrial process, characterized in that at least one ejector (1) 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 (7,8) that is arranged to operate through, and in parallel with the ejector, wherein the screw-rotor pump and the ejector are driven from one and same drive-gas source (P), and the drive-gas is directed to the screw-rotor pump through a valve (15) in response to a subpressure generated by the ejector.
Dependencies are inferred from the claim text.