System And Method For Evacuating A Vacuum Chamber

Abstract

A valve arrangement for a vacuum pump assembly selectively opens and closes communication between a vacuum pump, evacuation vessel, and a volume to be evacuated. The valve arrangement allows the evacuation vessel and any conduit connecting the vacuum pump and evacuation vessel to the volume to first be evacuated without providing a vacuum to the volume. The valve arrangement also allows the volume to be connected to the evacuation vessel but cut-off from the vacuum pump so that at initial stages of the evacuation process for the volume dead air contained within the volume may be communicated to the evacuation vessel rather than drawn out by the vacuum pump. Once the dead air, or portions thereof, has been removed from the volume, the valve arrangement may cut-off communication with the evacuation vessel, establish communication between the vacuum pump and the volume, and allow the vacuum pump to provide negative air pressure to the volume so that the volume may be evacuated.

1 . A vacuum pump assembly, comprising: 
 a vacuum pump defining a vacuum delivery outlet;    a vessel defining an interior and having a vessel outlet; and    a valve arrangement for selectively opening and closing both the vacuum delivery outlet and the vessel outlet;    wherein the pump assembly is adapted for interconnection with a volume to be evacuated, wherein the valve arrangement is operable to expose the volume to negative air pressure from the vessel interior and to thereafter cut off communication between the vessel interior and the volume and to supply negative air pressure to the volume from the vacuum delivery outlet.    
   
   
       2 . The pump assembly of  claim 1  wherein the valve arrangement is further configured to selectively expose the vessel interior to the vacuum delivery outlet for supplying negative air pressure to the vessel interior.  
   
   
       3 . The pump assembly of  claim 1  wherein the valve arrangement is further configured to selectively cut-off communication between the vacuum delivery outlet and the volume when the volume is exposed to negative air pressure from the vessel interior.  
   
   
       4 . The pump assembly of  claim 3  wherein the vacuum pump is located remote from the volume.  
   
   
       5 . The pump assembly of  claim 4  wherein the vessel is located proximate the volume.  
   
   
       6 . The pump assembly of  claim 1  further comprising a volume outlet and wherein the valve arrangement includes a valve for selectively opening and closing the volume outlet, and wherein the pump assembly further comprises a conduit connecting the vacuum delivery outlet to the vessel outlet and the volume outlet, and wherein the valve arrangement is operable to cut-off communication of the vacuum delivery outlet and the vessel outlet with the volume outlet to supply negative air pressure to the conduit.  
   
   
       7 . A method of supplying negative air pressure to a volume, comprising the steps of: 
 maintaining the interior of a vessel at a vacuum;    communicating negative air pressure from the vessel interior to the volume;    cutting off communication between the volume and the vessel interior; and    subsequently supplying negative air pressure to the volume from a vacuum pump.    
   
   
       8 . The method of  claim 7  further comprising the step of cutting off communication between the volume and vacuum pump before communicating negative pressure from the vessel interior to the volume.  
   
   
       9 . The method of  claim 8  further comprising the step of applying negative pressure to the vessel interior from the vacuum pump to create the vacuum in the vessel interior.  
   
   
       10 . The method of  claim 9  further comprising the step of cutting off communication between the vessel interior and the vacuum pump after the vacuum is created in the vessel interior to maintain the vessel at the vacuum.