Cooled nozzle assembly for urea/water injection

Abstract

A fluid-injecting system includes a nozzle assembly which includes a housing defining an outlet cooling passage, an outlet control passage, at least one inlet supply passageway, and an injection orifice. The nozzle assembly also includes a shaft disposed within the housing and movable between a closed position and an open position. The fluid-injecting system further includes a first valve in fluid communication with the nozzle assembly configured to regulate the supply of a fluid through the at least one inlet passageway and a second valve in fluid communication with the nozzle assembly to regulate a flow of fluid through the outlet passageway.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic illustration of an exemplary disclosed fluid-injecting system;

FIG. 2 is a diagrammatic illustration of an exemplary disclosed constituent reduction system; and

FIG. 3 is an end view of an exemplary disclosed nozzle assembly for use with the fluid injecting system of FIG. 1.

Claims

1. A fluid-injecting system, comprising: a nozzle assembly, including: a housing defining an outlet cooling passage, an outlet control passage, at least one inlet supply passageway, and an injection orifice;a shaft disposed within the housing and movable between a closed position at which fluid is prevented from exiting via the orifice and an open position at which fluid passes through the orifice;a first valve in fluid communication with the nozzle assembly to regulate the supply of a fluid though the at least one inlet supply passageway; anda second valve in fluid communication with the nozzle assembly to regulate a flow of fluid through the outlet control passageway.

2. The fluid-injecting system of claim 1, wherein the first valve in fluid communication with the nozzle assembly is a pulsing valve, located upstream of the nozzle assembly, and configured to vary the flow and pressure of the fluid supply within the nozzle assembly.

3. The fluid-injecting system of claim 2, wherein the pulsing valve is controlled in response to an engine operating condition.

4. The fluid-injecting system of claim 1, wherein the fluid is a mixture of urea and water.

5. The fluid-injecting system of claim 1, wherein: the second valve, when in a closed position, allows the nozzle assembly to be in an injecting mode;when in an open position, the second valve allows the nozzle to be in a non-injecting mode; andboth injecting and non-injecting modes maintain a self cooling function.

6. The fluid-injecting system of claim 1, wherein: the first valve, when in an open position, allows the nozzle assembly to be in an injecting and self-cooling mode; andwhen in a closed position, the first valve allows the nozzle to be in a non-injecting and non-self cooling mode.

7. The fluid-injecting system of claim 1, wherein: the at least one inlet includes a first and second passageway;the first passageway is in fluid communication with the first outlet fluid passage; andthe second passageway is in fluid communication with the second outlet fluid passageway and the orifice.

8. The fluid-injecting system of claim 7, wherein the shaft defines a bypass passage fluidly connecting the orifice and the second outlet fluid passageway.

9. The fluid-injecting system of claim 7, wherein the shaft defines a bypass passage configured to communicate a fluid between the one inlet fluid passageway and the first outlet fluid passage.

10. The fluid-injecting system of claim 1, further including a sleeve disposed within the housing and around the shaft, wherein the sleeve further includes a plurality of slots fluidly connected to the at least one inlet fluid passage and the slots are configured to direct a fluid into a chamber of the nozzle assembly at relative to a longitudinal axis of the shaft when the shaft is in the open position.

11. The fluid-injecting system of claim 10, wherein the shaft defines at least one feed hole in fluid communication with the chamber.

12. An exhaust treatment system, comprising: a fluid-injecting system configured to inject a water/urea mixture upstream of the catalyst substrate, the fluid injecting system comprising: a nozzle assembly, including: a housing defining a first outlet fluid passage, a second outlet fluid passage, at least one inlet fluid passageway, and an orifice; anda shaft disposed within the housing and movable between a closed position at which fluid is prevented from exiting via the orifice and an open position at which fluid passes through the at least one orifice;a first valve in fluid communication with the nozzle assembly to regulate the supply of a fluid though the at least one inlet fluid passageway; anda second valve in fluid communication with the nozzle assembly to regulate a flow of fluid through the first outlet fluid passageway; anda catalyst substrate disposed downstream of the fluid-injecting system.

13. The exhaust treatment system of claim 12, wherein the fluid is a mixture of urea and water.

14. The exhaust treatment system of claim 12, wherein the first valve in fluid communication with the nozzle assembly is a pulsing valve, located upstream of the nozzle assembly, and configured to vary the flow and pressure of the fluid supply within the nozzle assembly.

15. The exhaust treatment system of claim 12, wherein the sleeve further includes a plurality of slots configured to direct a fluid from the second fluid passage to a chamber of the nozzle assembly.

16. A method of injecting reductant comprising: supplying the reductant to a nozzle assembly;regulating the supply rate of reductant to the nozzle assembly;draining a portion of the reductant supplied to the nozzle assembly; andregulating a rate of reductant draining from the nozzle assembly to initiate injections of reductant.

17. The method of claim 16, wherein the fluid is a mixture of urea and water.

18. The method of claim 16, further including: utilizing a portion of supplied reductant to cool the nozzle assembly; anddraining the portion of the supplied reductant utilized to cool separate from the flow regulated to initiate injection.

19. The method of claim 16, further including supplying the reductant to a nozzle assembly in pulses.

20. The method of claim 16, further including swirling the fluid within the nozzle assembly.