Flow agitator

Patent metadata

Field	Value
Publication number	US-9587545-B2
Application number	US-201514605500-A
Country	US
Kind code	B2
Filing date	Jan 26, 2015
Priority date	Jan 26, 2015
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A fluid delivery system includes a flow agitator connected to a gas conduit and disposed within an internal cavity of the conduit at an upstream location with respect to a fluid injector. The flow agitator operates to separate the gas flow passing through the conduit during operation into a bypass flow, a control flow, and a main flow, such that a recombination of the bypass flow, the control flow, and the main flow downstream of the flow agitator creates an oscillation in the gas flow that also encompasses the fluid delivered into the internal cavity by the injector.

First claim

I claim:

1. A fluid delivery system for a conduit having a gas inlet, a gas outlet, and an internal cavity, in which a flow direction is defined for a gas flow entering the conduit through the gas inlet and exiting the conduit through the gas outlet, the fluid delivery system further comprising:
a fluid reservoir adapted to enclose a fluid therewithin;
a fluid pump fluidly connected to the fluid reservoir via a supply conduit and disposed to draw the fluid from within the fluid reservoir;
a fluid injector associated with the fluid pump and arranged to receive a pressurized fluid from the fluid pump, the fluid injector connected to a wall of the conduit and configured for delivery of fluid into the internal cavity of the conduit;
a flow agitator connected to the conduit and disposed within the internal cavity at an upstream location with respect to the fluid injector, the flow agitator comprising a body plate connected to an internal surface of the wall of the conduit that encloses the internal cavity, wherein the body plate comprises two offsets disposed on diametrically opposite ends of the body plate, and wherein the body plate is connected to the wall of the conduit through three tabs, two of which interconnecting the offsets with the wall and the third being connected directly between the body plate and the wall;
wherein the flow agitator operates to separate the gas flow during operation into a bypass flow, a control flow, and a main flow, such that a recombination of the bypass flow, the control flow, and the main flow downstream of the flow agitator, during operation, creates an oscillation in the gas flow that also encompasses the fluid delivered into the internal cavity by the fluid injector.

2. The fluid delivery system of claim 1 , wherein the conduit is part of an exhaust system of an engine, wherein the gas flow is an exhaust gas flow of the engine, and wherein the fluid is a diesel exhaust fluid containing urea.

3. The fluid delivery system of claim 1 , further comprising an evaporation and mixing arrangement of structures disposed within the internal cavity of the conduit at a location downstream from the fluid injector.

4. The fluid delivery system of claim 1 , wherein the body plate is generally shaped as a segment of an annular plate, the segment extending over an angle of between 120 and 180 degrees with respect to a conduit centerpoint.

5. The fluid delivery system of claim 1 , wherein the body plate that is formed by four panels, each of the four panels being generally shaped as an isosceles trapezoid having a long base edge and a short base edge connected by two isosceles side edges.

6. The fluid delivery system of claim 5 , wherein each pair of isosceles side edges is disposed at an angle, α, of about 36 degrees.

7. The fluid delivery system of claim 6 , wherein each of the four panels forms a rectangular window that is disposed generally centrally with respect to the isosceles trapezoidal shape of the corresponding panel.

8. The fluid delivery system of claim 7 , wherein each rectangular window forms an opening in each respective panel having an opening surface area that covers about ⅓ of a total surface area of the respective panel.

9. The fluid delivery system of claim 8 , wherein each panel further includes a rectangular, planar flap having a shape that substantially matches the respective window, wherein each respective flap is connected along a radially outer edge to the respective edge of the window.

10. The fluid delivery system of claim 9 , wherein each respective flap extends at a second angle, β, relative to the body plate.

11. The fluid delivery system of claim 10 , wherein the angle, β, is about of about 25 degrees in a downstream direction with respect to a plane defined by the body plate.

12. The fluid delivery system of claim 8 , wherein a radially outward gap is formed between a radially outward margin of the body plate and a radially inward surface of the wall.

13. The fluid delivery system of claim 12 , wherein the generally segmented, annular shape of the body plate also forms a central opening such that, during operation, the bypass flow is formed by a first portion of the gas flow passing through the radially outward gap, the control flow is formed by a second portion of the gas flow passing through the windows in the panels, and the main flow is formed, in part, by a third portion of the gas flow passing through the central opening.

14. A method of increasing a footprint of a urea deposition area onto a urea evaporator and mixer device disposed within an exhaust gas conduit associated with an internal combustion engine operating at a steady state, or a quasi-steady state, operating condition, comprising:
in the exhaust gas conduit, placing a urea injector upstream from the urea evaporator and mixer device relative to a direction of exhaust gas flow through the exhaust gas conduit;
placing a flow agitator upstream of the urea injector in the exhaust gas conduit, the flow agitator comprising a body plate having two offsets disposed on diametrically opposite ends of the body plate;
connecting the body plate to an internal surface of a wall of the exhaust gas conduit, the body plate connected to the wall of the exhaust gas conduit through three tabs, two of which interconnect the offsets with the wall and the third directly connects the body plate and the wall;
separating an exhaust gas flow into at least two portions including a control flow and a main flow as the exhaust gas flow passes through and around the flow agitator;
entraining an injected urea flow into the separated exhaust gas flow; and
inducing an oscillation in the exhaust gas flow as the control flow, the main flow and the injected urea are recombined such that deposition region of the injected urea onto an evaporator and mixer device changes with respect to space and time.

15. The method of claim 14 , further comprising separating the exhaust gas flow into a bypass flow, wherein separating the exhaust gas flow into three portions is accomplished by blocking a portion of the exhaust gas flow with the body plate of the flow agitator, which forms one or more window openings and is placed at an offset distance of a wall of the exhaust gas conduit, such that the gas flow passes through a gap formed by the offset distance, the control flow passes through the one or more window openings, and the main flow passes around the flow agitator.

16. The method of claim 15 , wherein the bypass flow and the main flow are accelerated with respect to the exhaust gas flow entering the exhaust gas conduit.

17. The method of claim 15 , wherein the control flow is redirected by a respective flap connected to the body plate and extending at an angle with respect thereto from an edge of a respective window opening.

18. A urea distribution system for an internal combustion engine, comprising:
a fluid reservoir adapted to enclose diesel exhaust fluid (DEF) therewithin, the DEF being an aqueous solution containing urea;
a DEF pump fluidly connected to the fluid reservoir via a supply conduit and disposed to draw the DEF from within the fluid reservoir;
a DEF injector associated with a fluid pump and arranged to receive pressurized DEF from the DEF pump, the DEF injector connected to a outer wall of a conduit and configured for delivery of DEF into an internal cavity of the conduit;
a flow agitator connected to the conduit and disposed within the internal cavity at an upstream location with respect to the DEF injector, the flow agitator comprising a body plate connected to an i

Assignees

• Caterpillar Inc

Inventors

• Venkataraghavan Jay

Classifications

• F01N3/2892 Primary

  Exhaust flow directors or the like, e.g. upstream of catalytic device · CPC title

• F01N2610/02

  the substance being ammonia or urea · CPC title

• B01D53/92

  of engine exhaust gases (exhaust {or silencing} apparatus {for internal combustion engines, machines or engines in general}, having means for purifying, {rendering innocuous} or otherwise treating exhaust gases F01N3/00) · CPC title

• F01N13/08 Primary

  Other arrangements or adaptations of exhaust conduits {(pipes, joints or supports therefor in general F16L; collecting or removing exhaust gases of vehicle engines in workshops B08B15/00, on highways E01C1/005)} · CPC title

• F01N3/2882

  Catalytic reactors combined or associated with other devices, e.g. exhaust silencers or other exhaust purification devices (combined with absorbents or adsorbents only F01N3/0814; combined with particulate filters F01N3/035) · CPC title