Powder jet pump

Abstract

A powder jet pump that is effective for creating a smoothly flowing gas stream with well dispersed particles.

What is claimed is: 
     
         1 . A powder jet pump, comprising:
 a main body having a particle inlet at a first end and an outlet connector at a second end, the particle inlet being in fluid communication with an inlet chamber;   a nozzle defining a passage in fluid communication with the chamber and outlet connector, wherein the nozzle includes a nozzle throat;   at least one suction inlet in fluid communication with the chamber;   an annular plenum positioned around the main body having a gas inlet; and   at least two jet passages each having an inlet opening into the annular plenum and an outlet opening within the nozzle throat.   
     
     
         2 . The powder jet pump of  claim 1 , wherein the gas inlet is configured to impart a direction of rotation within the annular plenum to a gas travelling through the gas inlet and into the annular plenum. 
     
     
         3 . The powder jet pump of  claim 2 , wherein respective outlet openings of the at least two jet passages are helically advanced in the direction of rotation relative to their respective inlet openings. 
     
     
         4 . The powder jet pump of  claim 1 , wherein the nozzle throat has a nozzle throat inner wall, and wherein the at least two jet passages are configured such that a portion of each jet passage adjacent to its respective outlet opening is disposed at an angle of 1 to 10 degrees relative to the nozzle throat inner wall. 
     
     
         5 . The powder jet pump of  claim 4 , wherein the at least two jet passages are configured such that a portion of each jet passage adjacent to its respective outlet opening is disposed at an angle of 1 to 10 degrees relative to the longitudinal axis of the nozzle throat. 
     
     
         6 . The powder jet pump of  claim 1 , wherein the nozzle throat has an inner diameter, wherein the nozzle has a maximum inner diameter, and wherein the ratio of the inner diameter of the nozzle throat to the maximum inner diameter of the nozzle is in the range of 1:2 to 1:10. 
     
     
         7 . The powder jet pump of  claim 1 , wherein the powder jet pump is unitary. 
     
     
         8 . The powder jet pump of  claim 1 , wherein the nozzle throat has a minimum inner diameter in the range of 0.03 inch (0.76 mm) to 0.11 inch (2.79 mm). 
     
     
         9 . The powder jet pump of  claim 1 , wherein the at least two jet passages have respective inner diameters in the range of 0.01 inch (0.25 mm) to 0.05 inch (1.27 mm). 
     
     
         10 . The powder jet pump of  claim 1 , wherein the at least two jet passages have respective lengths in the range of 0.10 inch (0.25 mm) to 1.00 inch (2.54 cm).