KR20150139968A - Engine exhaust after-treatment system - Google Patents

Abstract

The engine exhaust aftertreatment system includes an exhaust passage; An exhaust treated component housing communicating with the exhaust passage; A pair of baffles spaced apart in the housing; A plurality of exhaust treatment apparatuses positioned between the pair of baffles, each exhaust treatment apparatus comprising: a canister; A plurality of restraint devices secured between a pair of baffles for positioning each of the canisters between baffles, each restraining device comprising at least a portion of the restraint device inclined relative to an outer surface of the canister, Adjacent the outer surfaces of the canister at the first end and preventing radial movement of the canister; And a soot blower located in a housing upstream of the exhaust processing apparatuses for dispersing particulate matter deposited on each of the exhaust processing apparatuses.

Description

{ENGINE EXHAUST AFTER-TREATMENT SYSTEM}

The present invention relates to an engine exhaust aftertreatment system.

This section provides background information of the present invention that is not necessarily the prior art.

Combustion engines are known to produce exhaust gases that are harmful to the environment. In an effort to reduce the environmental consequences that the engine may have, exhaust aftertreatment systems have undergone extensive analysis and development. Various components that aid in the processing of engine exhaust include particulate filters and oxidation and reduction catalysts.

Over time, some of the various exhaust aftertreatment elements may require removal and maintenance. One way to accomplish this is to make the various post-treatment parts removable from the assembly, and then wash them separately. However, depending on the size of the engine application, the time and difficulty of this operation may increase. In this regard, large engine applications, such as locomotives, ships, and large self-powered applications, can produce substantially more exhaust gases than, for example, tractor trailer engine applications. The exhaust aftertreatment systems are therefore generally much larger in scale to adequately treat the exhaust gases produced by these large applications. As the size of the exhaust aftertreatment system increases, the ability to service such systems becomes substantially more difficult.

This section provides a general summary of the present invention, but is not intended to be exhaustive or to limit the scope of the invention to the full extent.

The present invention relates to an exhaust passage; An exhaust treated component housing communicating with the exhaust passage; A pair of baffles spaced apart in the housing; A plurality of exhaust treatment apparatuses positioned between the pair of baffles, each exhaust treatment apparatus comprising: a canister; A plurality of restraining devices secured between the pair of baffles for positioning each of the canisters between the baffles, each restraining device including at least a portion thereof angled relative to an outer surface of the canister The ends of the restraint device being adjacent the outer surfaces of the canister at the first end to prevent radial movement of the canister; And a soot blower located in a housing upstream of the exhaust treatment devices for dispersing particulate matter deposited on each of the exhaust treatment devices.

Other areas of application will become apparent from the description provided herein. The description and specific embodiments in this summary are intended for purposes of illustration only and are not intended to limit the scope of the invention.

The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the present invention, rather than all possible implementations.
1 is a schematic representation of an exhaust treatment system in accordance with the principles of the present invention.
2 is a perspective view of an exhaust aftertreatment system in accordance with the principles of the present invention.
3 is an enlarged perspective view of the exhaust aftertreatment system shown in FIG.
4 is a partially enlarged perspective view of an exhaust treated part according to the principle of the present invention.
5 is a perspective view of a housing of an exhaust treated component according to the principles of the present invention.
6 is a perspective view of the inside of the housing shown in Fig. 5 as viewed from the entrance side.
7 is a perspective view of the inside of the housing shown in Fig. 5 as viewed from the outlet side.
8 is a cross-sectional view taken along line 8-8 of Fig.
9 is an enlarged cross-sectional view of one of the exhaust-treated parts shown in Fig.
Corresponding reference numerals throughout the figures represent corresponding parts.

Preferred embodiments will now be described with reference to the accompanying drawings.

1 schematically shows an exhaust system 10 according to the present invention. The exhaust system 10 includes at least one engine 12 (not shown) in communication with a pair of fuel sources 14a and 14b to produce exhaust gases once exhausted into an exhaust passage 16 having an exhaust aftertreatment system 18 ). The fuel sources 14a and 14b may comprise different fuels. For example, the fuel source 14a may comprise low sulfur diesel fuel (LSF), and the fuel source 14b may comprise ultra low sulfur diesel fuel (ULSF). Other preferred fuels that may be used include marine gas oil (MGO), marine diesel oil (MDO), intermediate fuel oil (IFO), intermediate fuel oil (HFO), natural gas and diesel fuel A combination, or a mixture of natural gas with hydrogen. It should also be noted that any combination of the above-mentioned fuels may be stored in the fuel sources 14a and 14b.

An exhaust treated component 20 may be disposed downstream from the engine 12 and may include a diesel oxidation catalyst (DOC), a catalyst-coated diesel particulate filter (DPF) component, or a selective catalytic reduction (SCR) And may include a component 22. Although the selective catalytic reduction component 22 is shown, it should be understood that the selective catalytic reduction component 22 may also include a diesel oxidation catalyst or a diesel particulate filter therein. The selective catalytic reduction component 22 may also be a selective catalytic reduction catalyst-coated diesel particulate filter or an optional catalytic reduction catalyst-coated flow-through filter (FTF).

To help reduce the exhaust produced by the engine 12, the exhaust aftertreatment system 18 includes a dosing module 26 for periodically injecting exhaust treatment fluid into the exhaust stream . 1, the dosing module 26 may be located upstream of the exhaust aftertreatment component 18 and may be operable to inject the exhaust treatment fluid into the exhaust stream. In this regard, the dosing module 26 includes an inlet line 32 for injecting exhaust treatment fluid, such as diesel fuel or urea or gaseous ammonia, into the exhaust passageway 16 upstream of the exhaust treatment component 20, In fluid communication with the reagent tank 28 and the pump 30. The tank 28 may store liquid exhaust treatment fluids, or may store solid or gaseous ammonia. Other materials that may be used to enhance the evacuation process in association with the element may be ethanol or hydrogen, which may be stored in a separate tank (not shown).

The dosing module 26 may also be in fluid communication with the reagent tank 28 via a return line 34. The recovery line 34 allows any exhaust treatment fluid not injected into the exhaust stream to be recovered to the reagent tank 28. The flow of exhaust processing fluid through the inlet line 32, the dosing module 26, and the collection line 34 also helps to cool the dosing module 26 so that the dosing module 26 is not overheated . Although not shown in the drawings, the dosing module 26 may be configured to include a cooling jacket through which cooling water passes around the dosing module 26 to cool the dosing module.

The amount of exhaust processing fluid required to efficiently process the exhaust stream may vary depending on load, engine speed, exhaust gas temperature, exhaust gas flow, engine fuel injection time, desired nitrogen oxide reduction, atmospheric pressure, relative humidity, exhaust gas recirculation rate, May vary. The nitrogen oxide sensor or meter 36 may be located downstream from the selective catalytic reduction component 22. The nitrogen oxide sensor 36 can operate to output a signal indicative of the exhaust nitrogen oxide concentration to the engine control unit 38 (ECU). All or some engine operating parameters may be provided from the engine control unit 38 to the exhaust system controller 40 via the engine / vehicle data bus. The exhaust system controller 40 may also be included as part of the engine control unit 38. Exhaust gas temperature, exhaust gas flow and exhaust back pressure and other vehicle operating parameters can be measured by respective sensors, such as those shown in FIG.

The amount of exhaust treatment fluid required to efficiently process the exhaust stream may also depend on the size of the engine 12. [ In this regard, large diesel engines used in locomotives, offshore vessels, and stationary applications may have exhaust flow rates that exceed the capacity of the single dosing module 26. Thus, although a single dosing module 26 is shown for urea injection, it should be understood that multiple dosing modules 26 for urea injection can be considered.

During operation of the engine 12, the type of fuel provided to the engine 12, as described above, may be switched between different fuel sources 14a and 14b. It should be noted that when the engine 12 is using fuel with a high sulfur content, in which case the fuel sources 14a and 14b each have fuels with different sulfur contents, the post-treatment system 18 need not necessarily be used . That is, when the engine 12 is a marine application where the vessel is located a predetermined distance from the shore, the emission regulation may not require the use of the aftertreatment system 18. Thus, any exhaust produced by the engine 12 during use of the unique sulfur-containing fuel (or any type of fuel) can be vented into the atmosphere without passing through the aftertreatment system 18. [ The exhaust system 10 may include a by-pass pipe 44 to direct the exhaust into the atmosphere immediately before reaching the aftertreatment system 18.

The valve 48 may be located at the inlet of the bypass pipe 44 to permit exhaust gas to flow through the bypass pipe 44 or through the aftertreatment system 18. [ The valve 48 is in communication with the controller 40 or the engine control unit 38. Controller 40 or engine control unit 38 may control valve 48 to allow the atmosphere to exit the aftertreatment system 18 and into the atmosphere, Bypass pipe 44 and close the exhaust passageway 16 downstream of the valve 48. In this case, Similarly, when the engine 12 operates on an area where exhaust control requires post-exhaust treatment, the controller 40 or the engine control unit 38 may allow the exhaust to pass through the aftertreatment system 18 The valve 48 commands the bypass pipe 44 to close.

The fuel supplied to the engine 12 by the fuel tanks 14a and 14b is controlled through the valves 50a and 50b, respectively. The valves 50a and 50b are in communication with the controller 40 and / or the engine control unit 38. Controller 40 or engine control unit 38 may command valves 50a and 50b to open or close when it is desired to switch between the fuels provided by tanks 14a and 14b have. For example, if engine 12 switches from a high sulfur containing fuel to a low sulfur containing fuel, controller 40 or engine control unit 38 commands valve 50a to close and valve 50b opens . The controller 40 or the engine control unit 38 may determine that any combustion present in the exhaust stream is required before the controller 40 or the engine control unit 38 transmits commands to open or close the valves 50a and 50b (E.g., 300 [deg.] C) to such an extent that the unburned fuel can be burned. In this regard, if fuel switching is desired, the controller 40 or the engine control unit 38 may issue commands to activate the burner 24 and commands to activate the burner 24 for a predetermined period of time 50a and 50b, respectively.

It should be noted that while not necessary in the present invention, the valve 48 may be controlled to open the bypass pipe 44 during fuel switching while the burner 24 is activated. When the fuel conversion is complete and the burner 24 is deactivated, the valve 48 may close the bypass pipe 44 and allow the exhaust to pass through the exhaust aftertreatment system 18. In this way, it can be ensured that any unburned intrinsic sulfur-containing fuel can be prevented from reaching the selective catalytic reduction component 22.

In addition, the valve 48 may be designed to be synchronized with the fuel valves 50a and 50b. That is, if a signal is sent by the controller 40 to open the fuel valve 50b such that the engine 12 can operate on the low-sulfur containing fuel, Lt; RTI ID = 0.0 > 44 < / RTI > Similarly, if a signal is sent by the controller 40 to open the fuel valve 50a such that the engine 12 can operate on the proprietary sulfur-containing fuel, Lt; RTI ID = 0.0 > 18 < / RTI >

2-9, there is shown a preferred exhaust aftertreatment system 18 in accordance with the present invention. The post-treatment system 18 includes an exhaust passage 16 that provides the exhaust produced by the engine 12 to the exhaust aftertreatment component 20. A pair of mixing devices 52 may be disposed in the exhaust passage 16 at a location between the dosing module 26 and the exhaust treatment component 20. The mixing devices 52 help disperse the exhaust treatment fluid injected into the exhaust passage 16 and mix with the exhaust produced by the engine 12. [ Although a pair of mixing devices 52 is shown in Figures 2 and 3, it should be noted that more or fewer mixing devices 52 may be used without departing from the scope of the present invention. The exhaust aftertreatment system 18 may be supported by a plurality of support structures 53.

The inlet 54 of the bypass pipe 44 is located downstream from the mixing devices 52. Valve 48 may be positioned at inlet 54 and may be operated to allow exhaust to move within exhaust passageway 16 to bypass exhaust treatment component 20. [ Although not shown in FIG. 1, another valve 56 is also connected to the exhaust treatment port 20 to prevent fluid flow through the exhaust treated component 20 by the valve 56 when the bypass pipe 44 is operated. It may be located at the component inlet 58. [ In other words, if the valve 48 is open, the valve 56 is closed. Each of the valves 48 and 56 may be, for example, butterfly valves operated by a solenoid (not shown).

The bypass pipe 44 may be modular in design. For example, the bypass pipe 44 may include a pair of curved sections 60a and 60b connected through a plurality of intermediate sections 62, 64, and 66. Although intermediate sections 62 and 66 are shown in Figures 2 and 3 as being cylindrically shaped pipes, intermediate sections 62 and 66 may be formed from a flexible bellows (e.g., flexible bellows "). < / RTI > There may be an outlet 68 downstream of the section 60b of the curve to provide exhaust vented at a location downstream from the exhaust treated component 20 back into the exhaust passageway 16. The inlet 54 and outlet 68 of the bypass pipe 44 may be integral or integral with the exhaust passageway or may be curved sections 60a and 60b and intermediate sections 62, May be similar individually formed parts.

The exhaust treatment component 20 may include a housing 70 that supports a plurality of selective catalytic reduction parts 20. [ In the illustrated embodiment, the housing 70 is box-shaped and includes a plurality of outer panels 71. A plurality of trusses 73 may be disposed in the outer panels 71 of the housing 70. The trusses 73 may be L-shaped members disposed in the corners of the outer panels 71 within the interior of the housing 70. The trusses 73 provide structural support to the housing 70 and allow the housing 70 to support the respective selective catalytic reduction components 22. [ Similar to the trusses 73, cross-members provide structural support to the housing 70.

The housing 70 supports an array of nine selective catalytic reduction parts 22. Although nine selective catalytic reduction components 22 are shown in the figures, it should be understood that any number of selective catalytic reduction components 22 may be supported within the housing 70 without departing from the scope of the present invention. Any configuration for the selective catalytic reduction components 22 may be considered, but the selective catalytic reduction components 22 may be in the form of a cylinder.

The housing 70 may be disposed between an inlet cone 72 and an outlet cone 74. The inlet cone 72 includes a flange 76 corresponding to the flange 78 of the housing 70 and bolted to the flange 78. The outlet cone 74 may include a flange 80 corresponding to another flange 82 of the housing 70 and bolted to the flange 82. Such a configuration results in a tight, hermetically sealed exhaust treated component 20.

As best shown in FIG. 5, housing 70 may include an inlet side 84 and an outlet side 86. A particulate matter dispersing device 88 (here "soot blower") may be located at the inlet side 84. The soot blower 88 is designed and operates to discharge compressed air toward the selective catalytic reduction component 22 to disperse any sediment of particulate matter that may be produced on the selective catalytic reduction component 22. [ The soot blower 88 includes a plurality of arrays 90 of nozzle lines 92 and each nozzle line 92 includes a plurality of nozzles 92 for discharging compressed air toward the exhaust selective catalytic reduction component 22. [ (94). The nozzle lines 92 may be formed of a variety of metallic materials including aluminum, steel, copper, or any other material well known to those of ordinary skill in the art. The housing 70 may include a plurality of apertures (not shown) that allow the nozzle lines 92 to pass therethrough. A seat member 98 and a gasket 100 may be used to secure the nozzle lines 92 to the holes.

Although it is desirable and desirable to disperse particulate matter and / or soot on the surface of the selective catalytic reduction component 22, it should be understood that the present invention is not limited thereto. In contrast, the present invention also provides a soot blower 88 that is designed to prevent the generation of particulate matter and / or soot at locations other than the selective catalytic reduction component 22 surface. More specifically, particulate matter and / or soot can be made at locations other than the surface of the selective catalytic reduction component 22. If too much particulate matter and / or soot is produced in this "rectangular area" between the selective catalytic reduction components 22, the accumulation of particulate matter and / or soot will eventually cause the selective catalytic reduction components 22 to stop . Thus, it should be appreciated that the nozzles 94 may be positioned to exhaust compressed air at locations between the selective catalytic reduction parts 22 without departing from the scope of the present invention.

Referring now to Figures 4, 6 and 7-9, an exhaust treated component mounting system in accordance with the present invention will be described. The housing 70 may include a pair of baffles 102a and 102b to support each of the selective catalytic reduction components 22. The baffles 102a and 102b include a plurality of through holes 106 (FIG. 6) that can be welded to the inner surfaces 104 of the housing 70 and sized to receive selective catalytic reduction components 22 . Each selective catalytic reduction component 22 includes a canister 108 that houses a respective selective catalytic reduction substrate 110. An insulative mat 112 may be disposed between the canister 108 and the selective catalytic reduction substrate 110.

In order to secure the canisters 108 between the baffles 102a and 102b, a plurality of restraint devices 114 may be used. The constraining devices 114 may be linear (e.g., planar) members welded between the baffles 102a and 102b. Alternatively, the constraining devices 114 may be L-shaped in cross-section (FIG. 7). Nevertheless, at least a portion of the restraining device 114 is angled relative to the surface 116 of the canister 108 parallel to the axis A of the selective catalytic reduction part 22, (?). The angle alpha may be in the range of 1 to 20 degrees. Preferably, the angle alpha may be in the range of 5 to 15 degrees. More preferably, the angle alpha may be in the range of 5 to 10 degrees.

Because of at least a portion of the restraining device 114 that is inclined relative to the surface 116, the restraining device 114 is configured to restrict the movement of the selective catalytic reduction component 22 to the canister 108 at the first end 118 as the selective catalytic reduction component 22 is inserted into the housing 70. [ ). Once the constraining device 114 is adjacent the canister 108, radial movement of the selective catalytic reduction component 22 is prevented. Figs. 7 and 9 show the adjacency between the restraining device 114 and the canister 108. Fig. In addition, the proximity between the restraint devices 114 and the canister 108 helps to position the canister between the baffles 102a and 102b during the insertion of the canisters into the housing 70.

After the canister 108 is adjacent to the restraining device 114, the second end 120 of the canister 108 can be secured by bolting the ear members 122. The ear members 122 may be individually formed members welded to the second end 120 of the canister 108. Alternatively, a flange (not shown) extending radially to the canister 108 may be provided at the second end 120. Nevertheless, the ear piece 122 may be operable to receive a fastener 124 that bolts the ear member 122 and the canister 108 to the baffles 102a and 102b. As best shown in Figures 4-6, four restraint devices 114 (such as those shown by ear 122) can be used to secure the canister 108 between the baffles 102a and 102b have. It should be noted, however, that more or fewer constraining devices may be used without departing from the scope of the present invention.

It is not necessary to bolt the first end 118 of the canister 108 to the baffle 102a because the restraint devices 114 secure the first end 118 of the canister 108. [ The convenience in which the canisters 108 can be inserted and removed from the housing 70 can be increased. More specifically, if any of the selective catalytic reduction components 22 requires repair, then only the fasteners 124 need to be removed in order to remove the selective catalytic reduction components 122 from the housing 70 . This significantly reduces repair time compared to configurations where the selective catalytic reduction components 22 are bolted to the first and second ends 118 and 120 or welded to the baffles 102a and 102b. In order to help remove selective catalytic reduction components 22 from the housing 70, the ear piece 122 may include a tool for helping the operator pull the selective catalytic reduction components 22 from the housing 70 (Not shown).

BRIEF DESCRIPTION OF THE DRAWINGS For the purposes of illustration and explanation, there have been provided the description of the preceding embodiments. It is not intended to be exhaustive or to limit the invention. The individual elements or features of a particular embodiment are not generally limited to such specific embodiments and, if applicable, may be interchangeable and may be used in selected embodiments, even if not specifically shown or described. And may be varied in various other ways. Such variations are not to be regarded as being outside the scope of the invention, and all such modifications are intended to be included within the scope of the present invention.

10: Exhaust system
12: engine
14a, 14b: fuel source
16: exhaust passage
18: Exhaust post-treatment system
20: Exhausted parts
22: Selective Catalytic Reduction Parts
24: Burner
26: dosing module
28: Reagent tank
30: Pump
32: Entrance line
34: recovery line
36: Nitrogen oxide sensor
38: Engine control unit
40: controller
44: Bypass pipe
48: Valve
50a, 50b: valve
52: mixing device
53: Support structure
54: Entrance
56: Valve
58: Entrance of exhaust treated parts
60a and 60b: a section of the curve
62, 64, 66: Middle section
68: Exit
70: Housing
71: outer panel
72: inlet cone
73: Truss
74: Outlet cone
76: Flange
80, 82: Flange
84: inlet side
86: outlet side
88: sootblower
90: array
92: nozzle line
94: Nozzle
98: sheet member
100: Gasket
102a, 102b: baffle
104: inner surface of the housing
108: canister
110: selective catalytic reduction substrate
112: Insulation mat
114:
118: First end of the canister
120: second end of the canister
122: Ear member
123: hole
124: Fasteners

Claims (20)

housing:
A pair of baffles spaced apart in the housing;
A canister including an exhaust treated substrate positioned between the pair of baffles, the canister including a first end and a second end; And
A plurality of restraint devices secured between said pair of baffles for positioning said canisters between said baffles, each restraining device including at least a portion thereof inclined relative to an outer surface of said canister, Wherein the ends abut the outer surfaces of the canister at the first end to prevent radial movement of the canister.
2. The exhaust aftertreatment system of claim 1, wherein the second end of the canister is bolted to one of the baffles.
The exhaust aftertreatment system according to claim 1, wherein the exhaust treated substrate is a selective catalytic reduction substrate.
The exhaust aftertreatment system according to claim 1, further comprising a particulate matter dispersing device in the housing.
5. The exhaust aftertreatment system according to claim 4, wherein the particulate matter dispersing apparatus comprises a plurality of nozzle lines, each of the nozzle lines including a plurality of nozzles for dispersing particulate matter deposited on the exhaust- .
The exhaust aftertreatment system of claim 1, wherein a plurality of canisters are supported between the baffles in an array.
7. The exhaust aftertreatment system of claim 6, wherein each said canister corresponds to a plurality of restraint devices for positioning said canisters between said baffles.
The exhaust aftertreatment system of claim 1, wherein the restraint devices are adjacent the canister at an inlet side of the housing.
2. The exhaust aftertreatment system of claim 1, wherein said portion of said restraining device is inclined with respect to said outer surface of said canister at an angle (alpha) that is in the range of 1 to 20 degrees.
10. The exhaust aftertreatment system of claim 9, wherein the a is in the range of 5 to 15 degrees.
11. The exhaust aftertreatment system of claim 10, wherein the a is in the range of 5 to 10 degrees.
Exhaust passage;
An exhaust treated component housing communicating with the exhaust passage;
A pair of baffles spaced apart in the housing;
A plurality of exhaust treatment apparatuses each including a canister and located between the pair of baffles;
A plurality of restraint devices secured between the pair of baffles for positioning each of the canisters between the baffles, each restraining device including at least a portion thereof inclined relative to an outer surface of the canister, The ends of the apparatus being adjacent the outer surfaces of the canister at a first end and preventing radial movement of the canister; And
And a soot blower located in the housing upstream of the exhaust treatment devices for dispersing particulate matter deposited on each of the exhaust treatment devices.
13. The exhaust aftertreatment system of claim 12, wherein the second end of the canister is bolted to one of the baffles.
The exhaust aftertreatment system according to claim 12, wherein the exhaust-treated substrate is a selective catalytic reduction substrate.
13. The exhaust aftertreatment system of claim 12, wherein the soot blower comprises a plurality of nozzle lines, each of the nozzle lines including a plurality of nozzles.
13. The exhaust aftertreatment system of claim 12, wherein the restraint devices are adjacent the canister at an inlet side of the housing.
13. The exhaust aftertreatment system of claim 12, wherein the portion of the restraint device is inclined with respect to the exterior surface of the canister at an angle (?) That is in the range of 1 to 20 degrees.
13. The exhaust aftertreatment system of claim 12, further comprising a bypass pipe directing exhaust gases toward the periphery of the exhaust treated component housing.
19. The exhaust aftertreatment system of claim 18, wherein a first valve is disposed in the bypass pipe and a second valve is located at an inlet of the exhaust treated component housing.
20. The exhaust aftertreatment system of claim 19, wherein when the first valve is open, the second valve is closed.

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