Vacuum Generator on the Ejector Principle

Abstract

A vacuum generator which operates on the ejector principle. A multi-stage ejector has a plurality of nozzles arranged in a row. An air stream, an air from a compressed air connection flows through these nozzles at high speed to an outlet so that a negative pressure is generated in a valve chamber which surrounds the nozzles. A shut off valve closes the air outlet in an air tight fashion. The valve chamber or an evacuation chamber in which the negative pressure is generated has a conduit which is closed by an aeration valve which cooperates with the shut off valve, by which an aeration conduit for aerated the chambers in which the negative pressure is generatable is opened.

1 . A vacuum generator on the ejector principle, which has a multi-stage ejector with a plurality of nozzles arranged in a row, through which nozzles an air stream, deliverable via a compressed air connection, is carried at high speed to an air outlet, so that a negative pressure is generated in a valve chamber surrounding the nozzles, wherein in the air outlet, a shutoff valve is provided, by means of which the air outlet is closable in airtight fashion, and the valve chamber or an evacuation chamber in which the negative pressure is generated has an aeration conduit, which is closed by an aeration valve by means of which, in cooperation with the shutoff valve, an aeration conduit for aerating the said chambers, in which the negative pressure is generatable, is openable. 
     
     
         2 . The vacuum generator of  claim 1 , wherein the aeration valve is embodied as a differential pressure valve. 
     
     
         3 . The vacuum generator of  claim 1 , wherein the aeration conduit is connectable to a chamber that is subjected to compressed air. 
     
     
         4 . The vacuum generator of  claim 2  wherein the aeration valve is located between the aeration conduit and a venting conduit into the surroundings. 
     
     
         5 . The vacuum generator of  claim 4 , wherein the cross section of the venting conduit is greater than the cross section of the aeration conduit. 
     
     
         6 . The vacuum generator of  claim 5 , wherein the venting conduit has a diameter of approximately 2 mm, and the aeration conduit has a diameter of approximately 1.5 mm. 
     
     
         7 . The vacuum generator of  claim 1 , wherein the aeration valve is a movable element, which is movable freely in a valve chamber between a position that closes the aeration conduit and a position that closes the venting conduit. 
     
     
         8 . The vacuum generator of  claim 7 , wherein the valve chamber is in communication with an air conduit, through which a compressed air pulse for tripping the shutoff valve can be introduced. 
     
     
         9 . The vacuum generator of  claim 1 , wherein the shutoff valve is movable, counter to the action of a restoring spring, out of a position that opens the air outlet into a position that seals off the air outlet. 
     
     
         10 . The vacuum generator of  claim 1 , including a sound damper, via which the air flowing through the air outlet is carried.