Ejector with gas propulsion

Abstract

Ejector with driver gas comprising at least one primary nozzle branch ( 12 ) with a driver nozzle ( 36 ) having a cross-sectional narrowing and an adjacent receiving nozzle ( 32 ), wherein a suction line ( 24 ) terminates in the narrowing, characterized by at least one connectable secondary nozzle branch ( 14 ) having a driver nozzle ( 38 ) with a cross-sectional narrowing and an adjacent receiving nozzle ( 34 ), wherein the narrowing of the secondary nozzle branch ( 14 ) is connected to a suction line ( 24 ) when the secondary nozzle branch ( 14 ) is opened, and with a closing instrument ( 20 ) connected upstream, with respect to the flow direction of the gas propellant, of the at least one secondary nozzle branch ( 14 ) to connect and disconnect the secondary nozzle branch ( 14 ) in dependence on the inlet pressure of the driver gas entering the ejector ( 20 ).

We claim:  
     
         1 . An ejector having a driver gas at an inlet pressure, the ejector comprising: 
 at least one primary branch;    a primary driver nozzle disposed within said primary branch, said primary driver nozzle having a primary driver cross-sectional narrowing;    a primary receiver nozzle disposed downstream of and adjacent to said primary driver nozzle;    a primary suction line in vacuum communication with said primary driver narrowing;    at least one secondary branch;    a secondary driver nozzle disposed within said secondary branch, said secondary driver nozzle having a secondary driver cross-sectional narrowing;    a secondary receiver nozzle disposed downstream of and adjacent to said secondary driver nozzle;    a secondary suction line in interruptable vacuum communication with said secondary driver narrowing; and    a closing instrument disposed upstream of said secondary driver nozzle to connect and disconnect said secondary branch in dependence on the inlet pressure of the driver gas into the ejector.    
     
     
         2 . The ejector of  claim 1 , wherein said closing instrument is held in a first position through a biasing force means, said biasing force means counteracting the inlet pressure of the driver gas.  
     
     
         3 . The ejector of  claim 2 , wherein said closing instrument comprises a piston.  
     
     
         4 . The ejector of  claim 3 , wherein said biasing force means comprises a spring which acts on said piston.  
     
     
         5 . The ejector of  claim 1 , wherein said closing instrument is transferred to a second position when a switching pressure is reached by the inlet pressure of the driver gas.  
     
     
         6 . The ejector of  claim 5 , wherein said at least one secondary branch is disconnected when the inlet pressure is lower than said switching pressure.  
     
     
         7 . The ejector of  claim 5 , wherein said at least one secondary branch is disconnected when the inlet pressure is higher than said switching pressure.  
     
     
         8 . The ejector of  claim 1 , further comprising a common driver gas feed line communicating with said primary and said secondary branches, wherein said closing instrument is disposed in said feed line.  
     
     
         9 . The ejector of  claim 1 , wherein said primary suction line and said secondary suction line coincide, and further comprising a check valve disposed in said primary and secondary suction line between said secondary branch and said primary branch to prevent leakage of vacuum generated by said primary branch when said secondary branch is disconnected.  
     
     
         10 . The ejector of  claim 1 , wherein each nozzle branch or each group of nozzle branches is/are associated with a separate suction line.  
     
     
         11 . The ejector of  claim 9 , wherein said check valve is a spring-loaded ball valve.  
     
     
         12 . The ejector of  claim 1 , wherein said secondary branch has a same suction performance as said primary branch.  
     
     
         13 . The ejector of  claim 1 , wherein said secondary branch has a different suction performance than said primary branch.  
     
     
         14 . The ejector of  claim 13 , wherein said secondary branch has a larger suction performance than said primary branch.  
     
     
         15 . The ejector of  claim 1 , further comprising a housing, wherein suction lines are bores in said housing and nozzles and valves are disposed in said housing in an exchangeable manner.