Method for adjusting flow rate exhausted into a vacuum generator and vacuum generator with adjustable flow rate

Abstract

The invention relates to a vacuum generator ( 1 ) of the type comprising at least one nozzle ( 2 ) and a compressed air mixer ( 3 ) communicating with a vacuum chamber ( 4 ). This vacuum generator ( 1 ) is characterized in that the nozzle ( 2 ) and/or the mixer ( 3 ) are formed of at least two elements (7A, 7B) assemblable along a joint plain ( 9 ) to permit the possible insertion in said joint plain ( 9 ) of at least one spacer ( 8 ), the spacer ( 8 ) permitting a modification of the passage cross section of the nozzle ( 2 ) and/or of the mixer ( 3 ) as a function of the choice of the flow rate to be drawn into the vacuum chamber.

1 . Process for the adjustment of the flow rate drawn into a vacuum generator ( 1 ) of the type comprising at least one nozzle ( 2 ) and a mixer ( 3 ) of compressed air communicating with a vacuum chamber ( 4 ), 
 characterized in that the nozzle ( 2 ) and/or the mixer ( 3 ) are formed by assembling along a joint plane ( 9 ) at least two elements ( 7 A,  7 B) and in that there is caused to vary, if necessary, as a function of the choice of flow rate to be drawn into the vacuum chamber ( 4 ), the geometry of the compressed air nozzle ( 2 ) and/or of the mixer ( 3 ) in the sense of increasing the passage cross-section by insertion into said joint plane ( 9 ) at least one spacer ( 8 ).    
     
     
         2 . Process for the adjustment of the flow rate drawn into a vacuum generator ( 1 ) according to  claim 1 , 
 characterized in that there is selected the ratio of the cross-sections of the nozzle ( 2 )—mixer ( 3 ) to predetermine a vacuum level and in that there is caused to vary correspondingly the passage cross-section of the nozzle ( 2 ) and of the mixer ( 3 ) to obtain, for this predetermined constant vacuum level, an adjustment of the flow rate drawn into the vacuum chamber ( 4 ) as a function of the selected passage cross-sections.    
     
     
         3 . Vacuum generator ( 1 ), in particular for the practice of the process according to one of claims  1  and  2 , this generator ( 1 ) comprising at least one nozzle ( 2 ) and a compressed air mixer ( 3 ) communicating with a vacuum chamber ( 4 ), 
 characterized in that the nozzle ( 2 ) and/or the mixer ( 3 ) are formed of at least two elements ( 7 A,  7 B) assembleable along a joint plane ( 9 ) to permit the possible insertion into said joint plane ( 9 ) of at least one spacer ( 8 ), this spacer ( 8 ) permitting a modification of the passage cross-section of the nozzle ( 2 ) and/or of the mixer ( 3 ) as a function of the choice of flow rate to be drawn into the vacuum chamber.  
 
     
     
         4 . Vacuum generator ( 1 ) according to  claim 3 , 
 characterized in that the spacer ( 8 ) has an internal profile similar to that of the nozzle ( 2 ) and/or of the mixer ( 3 ).    
     
     
         5 . Vacuum generator ( 1 ) according to one of claims  3  and  4 , 
 characterized in that the spacer ( 8 ) has an internal profile defined to permit a simultaneous variation in correspondence with the passage cross-section of the nozzle ( 2 ) and of the mixer ( 3 ) whilst maintaining a constant ratio between the passage cross-sections of the nozzle ( 2 ) and of the mixer ( 3 ).  
 
     
     
         6 . Vacuum generator ( 1 ) according to one of  claims 3  to  5 , 
 characterized in that the spacers ( 8 ) have the shape of profiled plates.  
 
     
     
         7 . Vacuum generator ( 1 ) according to one of  claims 3  to  6 , 
 characterized in that each constituent element ( 7 A,  7 B) of the generator assmbleable along a joint plane, forms each time a monobloc assembly comprising at least one nozzle portion ( 2 ) and a mixer portion ( 3 ).  
 
     
     
         8 . Vacuum generator ( 1 ) according to one of  claims 3  to  7 , 
 characterized in that each constituent element ( 7 A,  7 B) of the generator ( 1 ), and assembleable along a joint plane, comprises, upstream of the nozzle ( 2 ), at least one portion of a compressed air supply chamber ( 5 ) for the nozzle ( 2 ) and, downstream of the mixer ( 3 ), at least one portion of an exhaust chamber ( 6 ).  
 
     
     
         9 . Vacuum generator ( 1 ) according to one of  claims 3  to  8 , 
 characterized in that it is constituted by two base elements ( 7 A,  7 B) assembleable along a joint plane ( 9 ) in which can be inserted at least one spacer ( 8 ), each base element ( 7 A,  7 B) constituting a half shell.