GB2549507A

GB2549507A - Mounting arrangement for fluid injector of exhaust aftertreatment system

Info

Publication number: GB2549507A
Application number: GB1606847.0A
Authority: GB
Inventors: E Snyder Matthew; R Tummala Srikanth; E Freeman Susannah
Original assignee: Perkins Engines Co Ltd
Current assignee: Perkins Engines Co Ltd
Priority date: 2016-04-20
Filing date: 2016-04-20
Publication date: 2017-10-25
Anticipated expiration: 2036-04-20
Also published as: GB2549507B

Abstract

A mounting arrangement for a fluid injector 14, eg a diesel exhaust fluid (DEF) injector, of an exhaust aftertreatment system of an engine includes a first annular member 34 having one end 36 received in the opening of a housing 18 and its opposite end 38 attached to a mixing chamber 46 in the housing 18. A second annular member 40 has one end 44 attached to the first annular member 34; the injector 14 is coupled to the other end 42 of the second annular member with the axis F of the injector 14 inclined at an angle A to the axis M of the mixing chamber 46, eg by means of the ends 42, 44 of the second annular member 40 being inclined to each other. Pressurised atomized fluid, eg reductant, is injected from the outlet 50 of the injector 14 towards the axis M of the mixing chamber 18.

Description

MOUNTING ARRANGEMENT FOR FLUID INJECTOR OF EXHAUST AFTERTREATMENT SYSTEM

Technical Eield [0001] The present disclosure relates to an exhaust aftertreatment system and more particularly relates to a mounting arrangement for a fluid injector of the exhaust aftertreatment system.

Background [0002] Generally, an exhaust aftertreatment system of an engine includes various components, such as a selective catalytic reduction (SCR) catalyst, a Diesel Oxidation Catalyst (DOC), a Diesel particulate Filter (DPF) to remove particulate matter from exhaust gas, and a Diesel Exhaust Fluid (DEF) injector. The DEF injector is used to inject reductant, such as a Diesel Exhaust Fluid (DEF) into exhaust gas flowing through a mixing chamber of the exhaust aftertreatment system. For instance, if the DEF injector has to be mounted to the exhaust aftertreatment system, there may be a need for a mounting arrangement to facilitate mounting of the DEF injector to a housing of the exhaust aftertreatment system. Modifying the mounting arrangement for mounting a DEF injector having different design specification to the exhaust aftertreatment system adds cost to the exhaust aftertreatment system. Due to geometric discontinuities, such as sharp edges, and narrow flow path within the exhaust aftertreatment system, the DEF when injected may get deposited on such geometric discontinuities.

[0003] US Patent Number 8,991,160 (the Ί60 patent) describes a mixing device including an elbow pipe attached to an outlet pipe of a filter device. The elbow pipe changes a flow direction of an exhaust gas flowing from the filter device. A straight pipe is connected to a downstream side of the elbow pipe. The straight pipe extends in a direction intersecting an axial line of the outlet pipe. An injector is attached to the elbow pipe and injecting a reductant aqueous solution inside the elbow pipe toward the straight pipe. A mixing pipe is disposed in the elbow pipe to serve as a cover for the reductant aqueous solution. The mixing pipe is provided with openings on a circumferential wall thereof. A plurality of large openings are provided on a circumferential wall of the mixing pipe near the injector and a plurahty of small openings are provided on a circumferential wall of the mixing pipe near the straight pipe. However, the ’ 160 patent fails to disclose a mounting arrangement for the injector that is cost effective.

Summary of the Disclosure [0004] In one aspect of the present disclosure, a mounting arrangement for a fluid injector of an exhaust aftertreatment system of an engine is provided. The exhaust aftertreatment system includes a housing member having an opening and a mixing chamber disposed within the housing member. The mounting arrangement includes a first annular ring member having a first end and a second end distal to the first end. The first end is received through the opening of the housing member. The first annular ring member includes a first inner surface extending between the first end and the second end. The first annular ring member further includes an outer surface including a first portion defined at the first end of the first annular ring member. The first portion is received through the opening of the housing member. The outer surface further includes a second portion defined at the second end of the first annular ring member. The second portion is adapted to engage with the mixing chamber. The mounting arrangement further includes a second annular ring member having a first end and a second end distal to the first end. The first end is adapted to couple to the fluid injector and the second end is coupled to the first end of the first annular ring member. The second annular ring member includes a second inner surface extending between the first end and the second end. The second inner surface and the first inner surface of the first annular ring member together define a flow path for fluid injected by the fluid injector. The second annular ring member further includes a coupling face defined at the first end of the second annular ring member. The coupling face is adapted to engage with an abutment surface of the fluid injector. The fluid injector is coupled to the second annular ring member at an angle with respect to an axis defined by the mixing chamber.

[0005] Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

Brief Description of the Drawings [0006] FIG. 1 is a side view of an exhaust aftertreatment system of an engine having a fluid injector; [0007] FIG. 2 is a partial cross-sectional view of the exhaust aftertreatment system of FIG. 1 showing a mounting arrangement for the fluid injector, according to an embodiment of the present disclosure; [0008] FIG. 3 is an exploded view showing a cross-sectional view of the mounting arrangement of FIG. 2; and [0009] FIG. 4 is a perspective view showing a second annular ring member of the mounting arrangement of FIG. 2.

Detailed Description [0010] Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. Moreover, references to various elements described herein, are made collectively or individually when there may be more than one element of the same type. However, such references are merely exemplary in nature. It may be noted that any reference to elements in the singular may also be construed to relate to the plural and vice-versa without limiting the scope of the disclosure to the exact number or type of such elements unless set forth explicitly in the appended claim.

[0011] FIG. 1 illustrates a side view of an exhaust aftertreatment system 10 of an engine 12, having a fluid injector 14. The engine 12 may be an internal combustion engine operated on fuels, such as diesel, gasoline, a gaseous fuel, or a combination thereof For example, the engine 12 may be a spark ignition engine, or a compression ignition engine, such as a diesel engine, a homogeneous charge compression ignition engine or any other compression ignition engines known in the art. The engine 12 may further include multiple cylinders defined in various configurations, such as ‘V’ type configuration and in-line configuration. In an example, the engine 12 may be used to power machines, such as an on-highway machine, an off-highway machine, earth moving equipment, and an electric generator.

[0012] The exhaust aftertreatment system 10 includes a first duct 20 and an inlet 22 provided in the first duct 20 to aid in fluid communication between the exhaust aftertreatment system 10 and an exhaust manifold 16 of the engine 12. During operation of the engine 12, the first duct 20 receives the exhaust gas from the exhaust manifold 16. The exhaust gas includes oxides of nitrogen (ΝΟχ), unburnt hydrocarbons, particulate matter, and/or other combustion products. In an example, the first duct 20 may contain various exhaust gas treatment devices, such as, but not limiting to, a Diesel Oxidation Catalyst (DOC) and a Diesel Particulate Filter (DPF). The DOC may be used to reduce unburnt hydrocarbons and carbon monoxide in the exhaust gas. Further, as the exhaust gas passes through the DPF, particulate matter contained in the exhaust gas may be trapped and prevented from being emitted to the atmosphere. Thus, the exhaust aftertreatment system 10 may be adapted to trap or convert ΝΟχ, unburnt hydrocarbons, particulate matter, and combinations thereof, before the exhaust gas is emitted to the atmosphere.

[0013] The exhaust aftertreatment system 10 further includes a housing member 18 that is coupled to the first duct 20. In an example, the housing member 18 may be made of a heat resistant material to withstand temperature of the exhaust gas received therein. The housing member 18 is further coupled to a second duct 24 of the exhaust aftertreatment system 10. Specifically, the first duct 20 and the second 24 are disposed parallel to each other and coupled via the housing member 18. Such coupling of the first duct 20 and the second duct 24 with the housing member 18 causes a flow of the exhaust gas to rotate 180 degrees to create a swirling motion of the exhaust gas.

[0014] The exhaust gas is treated through the DOC and the DPF and further enters the second duct 24. The exhaust aftertreatment system 10 further includes a third duct 25 coupled to the second duct 24 to receive the exhaust gas from the second duct 24. In an example, the third duct 25 absorbs oxides of ammonia from the exhaust gas, if any additional reductant is injected to exhaust gas stream. In an example, the first duct 20 and the second duct 24 may be embodied as ducts having circular cross-sections. However, it will be understood that size and cross-section of the first duct 20 and the second duct 24 may be determined based on the implementation and space availability for deploying the exhaust aftertreatment system 10.

[0015] The fluid injector 14 is mounted on the housing member 18 of the exhaust aftertreatment system 10 via a mounting arrangement 30. Specifically, the fluid injector 14 is positioned at a junction where the first duct 20 is connected to the second duct 24. More specifically, the fluid injector 14 is positioned in proximity to the second duct 24. The manner in which the mounting arrangement 30 facilitates mounting the fluid injector 14 with the housing member 18 is described with respect to FIG. 2 and FIG. 3. A reductant is injected, or sprayed, into exhaust gas stream by the fluid injector 14, while the exhaust gas enters the second duct 24 from the first duct 20. The fluid injector 14 receives the reductant from a reservoir (not shown). The reductant injected may be a fluid, such as, a Diesel Exhaust Fluid (DEF). In an example, the reductant may include urea, ammonia, or other reducing agents known in the art. The DEF sprayed into the exhaust gas reduces the ΝΟχ into Nitrogen and water vapor. The exhaust gas, in reduced form, further passes towards an outlet 26 of the exhaust aftertreatment system 10 for being emitted to the atmosphere through a tailpipe (not shown). The exhaust aftertreatment system 10 may also recirculate a portion of the exhaust gas to cylinders (not shown) of the engine 12 via an exhaust gas recirculation valve, where the portion of the exhaust gas recirculated mixes with charge being fed to the cylinders.

[0016] FIG. 2 illustrates a partial cross-sectional of the exhaust aftertreatment system 10 of FIG. 1 showing the mounting arrangement 30 for the fluid injector 14. The housing member 18 includes an opening 32. The mounting arrangement 30 includes a first annular ring member 34 having a first end 36 and a second end 38 distal to the first end 36. The first end 36 and the second end 38 define a width of the first annular ring member 34. The first end 36 of the first annular ring member 34 is received through the opening 32 of the housing member 18. More specifically, the first end 36 of the first annular ring member 34 is welded to the housing member 18. The exhaust aftertreatment system 10 further includes a mixing chamber 46 disposed in the second duct 24 and attached to the first annular ring member 34. In an example, the mixing chamber 46 may be coupled to the first annular ring member 34 by a press fit method or any other method of coupling known in the art. The mixing chamber 46 is aligned with the second duct 24 of the exhaust aftertreatment system 10.

[0017] The mounting arrangement 30 further includes a second annular ring member 40 having a first end 42 and a second end 44. The first end 42 and the second end 44 define a width of the second annular ring member 40. The first end 42 of the second annular ring member 40 is coupled to the fluid injector 14. Specifically, the first end 42 of the second annular ring member 40 is welded to the fluid injector 14.The first end 42 of the second annular ring member 40 is inclined at an angle with respect to the second end 44. The fluid injector 14 is coupled to the first end 42 of the second annular ring member 40. As such, the fluid injector 14 lies inclined with respect to the second end 44 of the second annular ring member 40. For example, the fluid injector 14 may have an axis “F” and the mixing chamber 46 may have an axis “M”, as shown in FIG. 3. Due to the inclination of the first end 42 of the second annular ring member 40, the axis “F” of the fluid injector 14 is inclined at an angle “A” with respect to an axis “M”. Further, the second end 44 of the second annular ring member 40 is coupled to the first end 36 of the first annular ring member 34.

[0018] The fluid injector 14 includes an inlet (not shown) and an outlet 50. The reductant received by the fluid injector 14 through the inlet may be pressurized and supplied towards the outlet 50 of the fuel injector 14. The fluid injector 14 is adapted to atomize the reductant and inject the reductant, at the angle “A” into the mixing chamber 46, and therefore into the second duct 24.

[0019] During operation of the engine 12, the exhaust gas received in the first duct 20 enters the second duct 24 for being treated by the exhaust aftertreatment system 10. The exhaust gas flowing into the second duct 24, from the first duct 20, may be associated with the swirling motion. Such swirling motion of the exhaust gas desired mixing of the exhaust gas with the fluid injected by the fluid injector 14, thereby creates turbulence in the flow of the exhaust gas. In addition, the entry of the exhaust gas into the second duct 24 may develop an angular momentum in the second duct 24. Simultaneously, the inlet of the fluid injector 14 receives reductant from the reservoir. Injection of the reductant at the angle “A” into the second duct 24 through the mixing chamber 46 causes development of turbulence in the exhaust gas. A force with which the reductant is injected into the second duct 24 causes the exhaust gas to gain momentum and thereby be forced towards the tailpipe.

[0020] FIG. 3 illustrates an enlarged view of the mounting arrangement 30. For the purpose of illustration, the fluid injector 14 and a gasket 78 is shown separately. The first annular ring member 34 of the mounting arrangement 30 includes a first inner surface 52 extending between the first end 36 and the second end 38. The first annular ring member 34 further includes an outer surface 54. The outer surface 54 includes a first portion 56 defined at the first end 36 of the first annular ring member 34. The first portion 56 is received through the opening 32 of the housing member 18. As mentioned earher, the mixing chamber 46 is press-fitted to the first annular ring member 34. For the purpose of description, the mixing chamber 46 and the first annular ring member 34 may be considered as mixing chamber assembly. In order to couple the mixing chamber assembly to the housing member 18, the mixing chamber assembly may be co-axially introduced into the second duct 24 from one end of the second duct 24 until the first portion 56 is received in the opening 32 of the housing member 18. In particular, the first portion 56 includes a first contact surface 62 and a second contact surface 64. The first contact surface 62 abuts a periphery of the opening 32 of the housing member 18 when the first annular ring member 34 is received in the opening 32.

[0021] The outer surface 54 of the first annular ring member 34 further includes a second portion 58 defined at the second end 38 of the first annular ring member 34. The second portion 58 includes a first contact surface 66. The first contact surface 66 of the second portion 58 engages with the mixing chamber 46 of the exhaust aftertreatment system 10. The outer surface 54 further includes a third portion 60 that defines an outer diameter “Dl” greater than an inner diameter “D2” of the opening 32 of the housing member 18. The first portion 56 extends from the third portion 60 in a direction away from the second portion 58. In an assembled condition, the first portion 56 protrudes from an outer surface 69 of the housing member 18, as shown in FIG. 3. Such protrusion functions as a positioning member for coupling the second annular ring member 40 with the first annular ring member 34. During assembling of the mixing chamber assembly with the housing member 18, the third portion 60 of the first annular ring member 34 functions as a stopper to prevent further movement of the mixing chamber assembly, when the third portion 60 is in contact with an inner surface 61 of the housing member 18. In the illustrated embodiment, the protrusion of the first portion 56 is welded to an outer surface 63 of the housing member 18 via weld “Wl”. In an alternate embodiment, the third portion 60 of the first annular ring member 34 may be welded to the inner surface 61 via a weld.

[0022] As mentioned earlier, the mounting arrangement 30 includes the second annular ring member 40. The second annular ring member 40 includes a second inner surface 68 extending between the first end 42 and the second end 44 of the second annular ring member 40. The second inner surface 68 of the second annular ring member 40 and the first inner surface 52 of the first annular ring member 34 together define a flow path for the DPF injected by the fluid injector 14, when the second end 44 of the second annular ring member 40 is coupled to the first end 36 of the first annular ring member 34. In an example, the second inner surface 68 and the first inner surface 52 together define a curvilinear surface, as shown in FIG. 3.

[0023] The second annular ring member 40, shown in FIG. 4, further includes a coupling face 70. The coupling face 70 is defined at the first end 42 of the second annular ring member 40. The coupling face 70 engages with an abutment surface 72 of the fluid injector 14. The couphng face 70 further includes a plurality of holes 74, as shown in FIG. 4. The coupling face 70 is aligned with the abutment surface 72 of the fluid injector 14 to couple the fluid injector 14 at the angle “A”. The plurality of holes 74 aids in coupling of the fluid injector 14 onto the coupling face 70 via a plurality of fastening members (not shown). In an example, the plurality of fastening members may include bolts or any other fastening members known in the art.

[0024] The second annular ring member 40 further includes a step portion 80, as shown in FIG. 3, defined at the second end 44 of the second annular ring member 40. For coupling the second annular ring member 40 with the first annular ring member 34, the step portion 80 is, located with respect to the protrusion of the first portion 56 of the first annular ring member 34. Further, the step portion 80 contacts with the first portion 56. The step portion 80 includes a first contact surface 82 and a second contact surface 84. Upon contact of the second annular ring member 40 with the first annular ring member 34, the first contact surface 82 of the step portion 80 abuts the second contact surface 64 of the first portion 56 of the first annular ring member 34. The second contact surface 84 of the step portion 80 abuts a portion of the first inner surface 52 of the first annular ring member 34. In such a condition of abutment, the second annular ring member 40 may be welded to the first annular ring member 34 via a weld “W2”. The first end 42 of the second annular ring member 40 includes an opening 77, as shown in FIG. 4, for receiving the outlet 50 of the fluid injector 14, as shown in FIG. 3.

[0025] Further, the gasket 78 is disposed between the fluid injector 14 and the second annular ring member 40. In an example, the gasket 78 may be a mechanical seal that fills clearance between the fluid injector 14 and the coupling face 70. The gasket 78 prevents leakage of the fluid from the fluid injector 14 to outside. In an example, the gasket 78 is further configured to fill irregularities between the abutment surface 72 of the fluid injector 14 and the couphng face 70 of the second annular ring member 40.

Industrial Applicability [0026] The present disclosure relates to the mounting arrangement 30 for the fluid injector 14 of the exhaust aftertreatment system 10 of the engine 12. The mounting arrangement 30 includes the first annular ring member 34 and the second annular ring member 40. Such two piece cost effective mounting arrangement 30 may require minimal changes to existing parts of the exhaust aftertreatment system 10 during implementation. Owing to the angular disposition of the fluid injector 14 with respect to the second duct 24, the fluid injected into the second duct 24 is allowed to efficiently mix with the exhaust gas, thereby eliminating any deposition of the fluid in the second duct 24. Further, as the first inner surface 52 of the first annular ring member 34 and the second inner surface 68 of the second annular ring member 40 are aligned with each other. The first inner surface 52 and the second inner surface 68 define a continuous smooth flow path for a mixture of the exhaust gas and the reductant. In addition, due to the inclination of the fluid injector 14 and the second annular ring member 40, by virtue of gravity, any residual reductant present in the fluid injector 14 is drained into the mixing chamber 46. Therefore, the mounting arrangement 30 overcomes any stagnation of the reductant along the flow path of the exhaust aftertreatment system 10.

[0027] While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

Claims

Claim What is claimed is:
1. A mounting arrangement for a fluid injector of an exhaust aftertreatment system of an engine, the exhaust aftertreatment system including a housing member having an opening and a mixing chamber disposed within the housing member, the mounting arrangement comprising; a first annular ring member having a first end and a second end distal to the first end, the first end received through the opening of the housing member, the first annular ring member including: a first inner surface extending between the first end and the second end; and an outer surface including: a first portion defined at the first end of the first annular ring member and received through the opening of the housing member; and a second portion defined at the second end of the first annular ring member and adapted to engage with the mixing chamber; and a second annular ring member having a first end and a second end distal to the first end, the first end adapted to couple to the fluid injector and the second end coupled to the first end of the first annular ring member, the second annular ring member including: a second inner surface extending between the first end and the second end, wherein the second inner surface and the first inner surface of the first annular ring member together define a flow path for fluid injected by the fluid injector; and a coupling face defined at the first end of the second annular ring member and adapted to engage with an abutment surface of the fluid injector. wherein the fluid injector is coupled to the second annular ring member at an angle with respect to an axis defined by the mixing chamber.