Ejector

Abstract

An ejector having a nozzle portion having openings provided at a distal end and a proximal end thereof, respectively, for injecting drive-stream gas, a diffuser portion provided on a distal end side of the nozzle portion for drawing in auxiliary gas by negative pressure which is generated in the drive-stream gas by injection from the nozzle portion so as to join the auxiliary-stream gas together with the drive-stream and discharge the drive-stream gas and the auxiliary gas, a needle slidably inserted into an interior of the nozzle portion in an axial direction of the nozzle portion for adjusting an opening area of the nozzle portion in accordance with an inserted position thereof, a drive unit for moving the needle axially and an auxiliary stream introducing portion comprising at least two openings for introducing the auxiliary-stream gas into the diffuser portion therefrom.

1 . An ejector comprising: 
 a nozzle portion having openings provided at a distal end and a proximal end thereof, respectively, for injecting drive-stream gas;    a diffuser portion provided on a distal end side of the nozzle portion for drawing in auxiliary gas by negative pressure which is generated in the drive-stream gas by injection from the nozzle portion so as to join the auxiliary-stream gas together with the drive-stream and discharge the drive-stream gas and the auxiliary gas;    a needle slidably inserted into an interior of the nozzle portion in an axial direction of the nozzle portion for adjusting an opening area of the nozzle portion in accordance with an inserted position thereof;    a drive unit for moving the needle axially; and    an auxiliary stream introducing portion comprising at least two openings for introducing the auxiliary-stream gas into the diffuser portion therefrom.    
   
   
       2 . The ejector as set forth in  claim 1 , further comprising a buffer chamber provided on an upstream side of the auxiliary stream introducing portion, 
 wherein the auxiliary-stream gas is adopted to be introduced into the plurality of openings from the buffer chamber.    
   
   
       3 . The ejector as set forth in  claim 1 , wherein the ejector is used on a fuel cell system.  
   
   
       4 . The ejector as set forth in  claim 1 , wherein the openings of the auxiliary stream introducing portion are arranged along with a circumferential direction of the diffuser portion.  
   
   
       5 . The ejector as set forth in  claim 1 , wherein the openings of the auxiliary stream introducing portion are arranged in point symmetry manner relative to a central axis of the needle.