Pressure swirl flow injector with reduced flow variability and return flow

Abstract

A reagent injector with a cartridge design has a body with a reagent inlet, outlet, and a swirl chamber, which has an exit orifice that may be covered and uncovered by a solid, movable pintle. Reagent flows through the injector when the exit orifice is covered and uncovered to cool the injector. An insulator may be disposed between the injector body and a mounting flange connectable to an exhaust system. A flow path ensures cooling of an electromagnetic actuator. Reagent may bypass an orifice swirl chamber when the pintle blocks the exit orifice. Fluid may flow between an outside diameter of a pole piece and an inside diameter of an electromagnetic actuator, through an orifice chamber and return through a central bore housing a solid pintle, around which fluid may flow. Different inner injector body passages may direct fluid into an orifice distribution chamber and out to the solid pintle.

1 - 20 . (canceled) 
     
     
         21 . An injector for injecting reagent, the injector comprising:
 an upper injector body;   a lower injector body that is secured to the upper injector body;   a retaining plate defining a circular hole, the retaining plate secured around the lower injector body via the circular hole;   an insulator defining a circular hole, the insulator secured around the lower injector body; and   a mounting flange defining a circular hole, the mounting flange secured around the insulator.   
     
     
         22 . The injector of  claim 21 , wherein the retaining plate is secured directly against the lower injector body. 
     
     
         23 . The injector of  claim 21 , wherein the insulator is secured directly against the lower injector body and the retaining plate. 
     
     
         24 . The injector of  claim 21 , wherein the mounting flange is secured directly against the insulator. 
     
     
         25 . The injector of  claim 21 , wherein the retaining plate defines a plurality of through holes about a retaining plate peripheral edge and the mounting flange defines a plurality of blind holes about a mounting flange peripheral edge. 
     
     
         26 . The injector of  claim 25 , further comprising:
 a pin having a first pin end and a second pin end, wherein the first pin end resides within one of the blind holes of the mounting flange and the pin resides completely through one of the plurality of through holes of the retaining plate.   
     
     
         27 . The injector of  claim 26 , further comprising:
 a clip having a first clip end and a second clip end, the clip secured over the retaining plate peripheral edge and the mounting flange peripheral edge.   
     
     
         28 . The injector of  claim 27 , wherein the retaining plate peripheral edge defines a peripheral concavity and the plurality of through holes of the retaining plate are located within the peripheral concavity. 
     
     
         29 . The injector of  claim 28 , wherein the mounting flange peripheral edge defines a groove. 
     
     
         30 . The injector of  claim 29 , wherein the first clip end resides within the groove of the mounting flange peripheral edge and the second clip end resides within the peripheral concavity of the retaining plate peripheral edge. 
     
     
         31 . The injector of  claim 21 , wherein the clip is a C-shaped and the second clip end resides on the second pin end. 
     
     
         32 . The injector of  claim 31 , wherein the insulator defines a tubular section with an inside diameter and an outside diameter that each have a series of alternating protrusions and recessions. 
     
     
         33 . The injector of  claim 21 , further comprising:
 a heat shield defining a through hole, the mounting flange protruding through the through hole of the heat shield.   
     
     
         34 . The injector of  claim 33 , wherein the heat shield is positioned between the injector upper body and an exhaust pipe. 
     
     
         35 . The injector of  claim 34 , further comprising:
 a cover mounted to the heat shield, wherein the cover surrounds the upper injector body, the lower injector body, and the mounting flange.   
     
     
         36 . An injector for injecting reagent, the injector comprising:
 a cylindrical pole piece defining a pole piece first end, a pole piece second end and a hollow interior from the pole piece first end to the pole piece second end;   a spring pre-loader located within the hollow interior and against a portion of the first end;   a spring located within the hollow interior, the spring the abutting the spring pre-loader; and   an electromagnetic coil secured around a bobbin, the electromagnetic coil surrounding an outside diameter of the cylindrical pole piece, wherein the cylindrical pole piece, spring pre-loader, spring and electromagnetic coil reside only within the upper injector body.   
     
     
         37 . The injector of  claim 36 , further comprising:
 a cylindrical inner lower body defining a longitudinal central bore;   an inner lower body first end defining a first end first bore with a diameter larger than a diameter of the longitudinal central bore, the inner lower body first end also defining a first end second bore with a diameter larger than the longitudinal central bore and larger than the first end first bore; and   an inner lower body second end defining a second end bore with a diameter larger than the longitudinal central bore.   
     
     
         38 . The injector of  claim 37 , further comprising:
 a solid pintle residing within the longitudinal central bore;   a guide plate attached to an intermediate portion of the pintle, the guide plate residing within the first end first bore;   a pintle head surrounding an end of the pintle, the pintle head residing within the first end second bore; and   an orifice plate residing within the second end bore.   
     
     
         39 . The injector of  claim 38 , wherein the cylindrical pole piece, spring pre-loader, spring, electromagnetic coil, cylindrical inner lower body, pintle, guide plate, pintle head and orifice plate are part of a single cartridge. 
     
     
         40 . The injector of  claim 39 , further comprising:
 an injector body upper section defining a chamber, wherein the single cartridge inserts into and resides within the chamber.   
     
     
         41 . The injector of  claim 38 , wherein the guide plate defines at least one through hole for passage of fluid. 
     
     
         42 . The injector of  claim 38 , wherein the guide plate and the pintle define at least one through hole therebetween for passage of fluid. 
     
     
         43 . The injector of  claim 38 , wherein the pintle head defines at least one through hole for passage of fluid. 
     
     
         44 . The injector of  claim 38 , wherein the orifice plate and the inner lower body second end define a chamber therebetween. 
     
     
         45 . The injector of  claim 38 , wherein the orifice plate defines a plurality of grooves for passage of fluid. 
     
     
         46 . The injector of  claim 42 , further comprising:
 an injector body lower section, wherein an interior surface of the injector body lower section and an inner lower body exterior surface define a pathway.   
     
     
         47 . The injector of  claim 46 , wherein the inner lower body defines a distribution passage fluidly linked to the pathway defined by an interior surface of the injector body lower section and an exterior surface of the inner lower body. 
     
     
         48 . The injector of  claim 44 , wherein the inner lower body defines a return passage that fluidly links the inner lower body central bore and the chamber defined by the orifice plate and the inner lower body second end. 
     
     
         49 . The injector of  claim 48 , wherein the solid pintle resides within the longitudinal central bore for passage of fluid around the solid pintle. 
     
     
         50 - 52 . (canceled)