Exhaust gas treatment device

Abstract

This exhaust gas treatment device is provided with: an exhaust gas passage (20) through which exhaust gas flows; an injection unit (40) that injects urea water into the exhaust passage (20); an inclined plate (70) that is inclined within the exhaust passage (20) with respect to a virtual plane that is orthogonal to the direction in which the injection unit (40) injects the urea water; and an opposing plate (80) provided downstream of the inclined plate (70) in the exhaust passage (20) so as to face the inclined plate (70), the opposing plate (80) forming, with the inclined plate (70), an injection space in which the urea water is injected. The inclined plate (70) is provided with: a convex part (72) which is formed on an opposite surface opposite to the spraying part (40) and on which the urea water is sprayed; and a recess (73) that is formed on the back surface on the opposite side from the facing surface and forms a flow path for the exhaust gas.

Description

Technical Field

[0001] This invention relates to an exhaust gas treatment device for purifying exhaust gas. Background Technology

[0002] Japanese Patent Application Publication No. 2017-172332 discloses an engine with a collision body installed in the exhaust passage, the collision body having a collision surface for urea water injected by the injection unit to collide with. The engine has a heater that heats the collision surface to cause the urea water to evaporate and decompose to generate ammonia. Summary of the Invention

[0003] The problem the invention aims to solve However, the above structure requires electricity to be supplied between the heater and the collision surface, making the structure complex. Furthermore, in this structure, the urea solution tends to mix with the exhaust gas before colliding with the collision body, making it difficult for the urea solution to come into contact with the collision surface.

[0004] Therefore, the present invention has been made in view of these aspects, and its object is to efficiently promote the evaporation and decomposition of urea water with a simple structure.

[0005] means for solving problems In one aspect of the present invention, an exhaust treatment apparatus is provided, comprising: an exhaust passage for exhaust flow; a spraying part for spraying urea water into the exhaust passage; an inclined plate inclined relative to an imaginary plane within the exhaust passage, the imaginary plane being orthogonal to the spraying direction of the spraying part spraying the urea water; and an opposing plate disposed in the exhaust passage downstream of the inclined plate in a manner opposite to the inclined plate, and forming a spraying space for spraying the urea water with the inclined plate, wherein the inclined plate has: a protrusion formed on an opposing surface opposite to the spraying part, and the urea water being sprayed onto the protrusion; and a recess formed on a back surface opposite to the opposing surface, forming a flow path for the exhaust.

[0006] In addition, the recess may also be formed directly behind the protrusion.

[0007] In addition, the protrusion may also be located directly below the jet.

[0008] In addition, the protrusion and the recess may also be formed in the center of the inclined plate from the bottom to the top.

[0009] Furthermore, the protrusions and recesses can also be formed by bending a flat plate.

[0010] Furthermore, the lower part of the inclined plate can also be separated from the inner wall of the exhaust passage, and the exhaust treatment device can also include a connecting plate, which is connected to the lower part of the inclined plate and forms the space for the exhaust flow with the inclined plate.

[0011] Alternatively, inflow holes can be provided on both sides of the protrusion in the upper part of the inclined plate to allow the exhaust gas to flow into the injection space.

[0012] Alternatively, an outlet hole may be provided at the lower part of the opposing plate, which allows the ammonia gas generated from the urea water and the exhaust gas to flow out from the injection space.

[0013] Furthermore, the lower part of the inclined plate and the lower part of the opposing plate can also be separated from the inner wall surface of the exhaust passage. The exhaust treatment device may also include a lower plate, which is connected to the lower part of the inclined plate and the lower part of the opposing plate, and forms a gap with the inner wall surface.

[0014] In addition, the exhaust treatment device may also include a connecting plate that is connected to the lower part of the back side of the inclined plate and forms the space for exhaust flow with the lower part. Alternatively, the lower part of the connecting plate located below the lower plate and connected to the inner wall surface may have a passage hole for the exhaust to pass through.

[0015] The effects of the invention According to the present invention, it has the effect of efficiently promoting the evaporation and decomposition of urea water with a simple structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram showing the structure of an exhaust treatment device 1 according to one embodiment.

[0017] Figure 2 This is a schematic diagram showing the peripheral structure of the injection section 40 within the exhaust passage 20.

[0018] Figure 3 This shows the view from the front. Figure 2 A schematic diagram of its internal structure.

[0019] Figure 4 This shows the view from above. Figure 2 A schematic diagram of its internal structure.

[0020] Figure 5 This shows the view from the right side. Figure 2 A schematic diagram of its internal structure.

[0021] Figure 6 This is a perspective view showing the inclined plate 70.

[0022] Figure 7 This is a schematic diagram used to illustrate the flow of exhaust gas.

[0023] Explanation of reference numerals in the attached figures 1. Exhaust Treatment Device 20 Exhaust passage 40 jet section 70-degree inclined plate 72 convex part 73 concavity 74 Inflow Hole 80 Opposite Plate 81 outflow hole 83 connecting plate 84 Through the hole 86 lower plate Detailed Implementation

[0024] <Structure of the Exhaust Treatment Device> Figure 1 This is a schematic diagram showing the structure of an exhaust treatment device 1 according to one embodiment. Figure 1 As shown, the exhaust treatment device 1 includes an engine 10, an exhaust passage 20, a DPF (Diesel Particulate Filter) 30, an injection unit 40, and an SCR (Selective Catalytic Reduction) device 50. The exhaust treatment device 1 is, as an example, mounted on a truck or other vehicle to purify the exhaust from the engine 10.

[0025] Engine 10 is an internal combustion engine that generates power by burning and expanding a mixture of fuel and intake air. Engine 10 is, for example, a diesel engine, but is not limited to this.

[0026] The exhaust passage 20 is an exhaust pipe connected to the engine 10, which discharges the exhaust gas from the engine 10. A DPF 30, an injection unit 40, and an SCR device 50 are provided in the exhaust passage 20 through which the exhaust gas flows.

[0027] DPF30 is a filter that captures particulate matter (PM) in exhaust gas. DPF30 is made of, for example, a honeycomb structure of metal or ceramic, which captures PM through the pores of the septa or the surface.

[0028] An injection unit 40 is positioned between the DPF 30 and the SCR device 50, injecting urea solution into the exhaust passage 20. The urea solution injected by the injection unit 40 evaporates and decomposes due to the heat of the exhaust gas flowing in the exhaust passage 20, generating ammonia. Ammonia is used to reduce NO in the exhaust gas. x The reduction reaction. Details will be described later. A structure to promote the evaporation and decomposition of urea water is provided around the injection section 40 in the exhaust passage 20.

[0029] SCR device 50 is used to remove NO from exhaust gas. x A device that converts nitrogen into harmless nitrogen through a reduction reaction. SCR unit 50 promotes the reaction of ammonia and NO. x The reduction catalyst 52 is used in the reduction reaction. The reduction catalyst 52 adsorbs ammonia generated from urea solution. The reduction catalyst 52 utilizes the adsorbed ammonia to reduce NO. x Reduced to nitrogen and water, decreasing NO x The discharge.

[0030] <Peripheral Structure of the Jet Section> Reference Figures 2-7 The surrounding structure of the injection section 40 within the exhaust passage 20 will be described.

[0031] Figure 2 This is a schematic diagram showing the peripheral structure of the injection section 40 within the exhaust passage 20. Figure 3 This shows the view from the front. Figure 2 A schematic diagram of its internal structure. Figure 4 This shows the view from above. Figure 2 A schematic diagram of its internal structure. Figure 5 This shows the view from the right side. Figure 2 A schematic diagram of its internal structure. Figure 6 This is a perspective view showing the inclined plate 70. Figure 7 This is a schematic diagram used to illustrate the flow of exhaust gas. Additionally, in Figure 2 In the diagram, for ease of explanation, the exhaust passage 20 surrounding the inclined plate 70, the opposing plate 80, the connecting plate 83, and the lower plate 86 is indicated by dashed lines. Furthermore, in... Figure 3 The area enclosed by two dotted lines is the area where the urea solution is sprayed by the spray unit 40. Figure 7 In the diagram, dashed lines represent the flow of exhaust gas.

[0032] In this embodiment, multiple plates are provided at the lower part of the injection section 40 within the exhaust passage 20 to promote the evaporation and decomposition of the urea water sprayed by the injection section 40. Specifically, as shown... Figure 2 and Figure 3 As shown, an inclined plate 70, an opposing plate 80, a connecting plate 83, and a lower plate 86 are provided at the lower part of the spray section 40.

[0033] like Figure 3 As shown, the inclined plate 70 is located within the exhaust passage 20 at the spray destination of the urea solution from the spray section 40. Therefore, the urea solution sprayed by the spray section 40 adheres to the opposing surface of the inclined plate 70 opposite to the spray section 40. Figure 2As shown, the inclined plate 70 is shaped to block the exhaust passage 20. Specifically, a portion of the outer peripheral surface of the inclined plate 70 contacts the inner wall surface of the exhaust passage 20. Therefore, the rear of the inclined plate 70 is easily heated by exhaust. Holes are formed on the inclined plate 70 to allow exhaust to pass through. Figure 3 As shown, the lower part of the inclined plate 70 is separated from the inner wall of the exhaust passage 20.

[0034] like Figure 3 As shown, the inclined plate 70 is disposed in the exhaust passage 20 at an angle. Specifically, the inclined plate 70 is inclined within the exhaust passage 20 relative to an imaginary plane orthogonal to the spray direction of the urea solution sprayed by the spray unit 40 (since the spray direction is vertically downward, the imaginary plane is horizontal). Therefore, the urea solution sprayed by the spray unit 40 easily adheres to the inclined plate 70 over a large area. Furthermore, because of its inclination, even if the inclined plate 70 is located below the spray unit 40, the urea solution sprayed by the spray unit 40 easily adheres to the inclined plate 70.

[0035] Inclined plate 70 is the shape used to process the flat plate. For example... Figure 6 As shown, the inclined plate 70 has a symmetrical shape. The inclined plate 70 has a protrusion 72, a recess 73, and inflow holes 74 and 75.

[0036] like Figure 3 As shown, a protrusion 72 is formed on the opposing surface of the inclined plate 70, opposite to the spray portion 40. The protrusion 72 is the portion to which the sprayed urea solution adheres. The protrusion 72 is formed on the central side of the inclined plate 70. Specifically, as... Figure 6 As shown, a protrusion 72 is formed from the bottom to the top on the central side of the inclined plate 70. Furthermore, the protrusion 72 is a curved surface that is integrally curved at the center of the opposing surfaces. Here, as... Figure 4 As shown, the protrusion 72 is located directly below the spray section 40. By providing this type of protrusion 72 on the opposing surface, the surface area on which urea water adheres is increased.

[0037] A recess 73 is formed on the back side opposite to the opposing surface. The recess 73 forms the flow path for exhaust gas. Exhaust gas reaching the back side of the inclined plate 70 flows along the recess 73. Because the exhaust gas flows along the recess 73, the flow is concentrated within the recess 73, and the back side of the inclined plate 70 is heated to a high temperature. Consequently, the urea water adhering to the protrusion 72 of the inclined plate 70 evaporates and decomposes due to the high temperature of the inclined plate 70, generating ammonia gas. As a result, the accumulation of urea water due to evaporation and decomposition can be prevented, and blockage of the exhaust passage 20 due to accumulation can be prevented.

[0038] like Figure 6As shown, a recess 73 is formed from the bottom to the top on the central side of the back surface of the inclined plate 70. As a result, exhaust gas reaching the back surface of the inclined plate 70 flows from the top to the bottom of the inclined plate 70. Therefore, the exhaust gas heats the back surface of the inclined plate 70 for a longer period, which promotes the evaporation and decomposition of the urea water adhering to the protrusion 72 of the inclined plate 70.

[0039] The protrusion 72 and the recess 73 are formed by bending a flat plate. This facilitates the formation of an inclined plate 70 having the protrusion 72 and the recess 73. For example... Figure 6 As shown, the recess 73 is formed directly behind the protrusion 72. Therefore, the heat from the exhaust gas flowing through the recess 73 is easily transferred to the urea solution adhering to the protrusion 72.

[0040] like Figure 6 As shown, the inflow hole 74 is a hole provided in the upper part of the inclined plate 70. Specifically, the inflow hole 74 is a cutout provided on both sides of the protrusion 72 in the inclined plate 70. The inflow hole 74 allows exhaust gas to flow into the injection space R of the injection section 40 (e.g., Figure 3 As shown, the space surrounded by the inclined plate 70 and the opposing plate 80. That is, as Figure 7 As shown, a portion of the exhaust gas reaching the inclined plate 70 flows into the injection space R through the inlet orifice 74.

[0041] like Figure 6 As shown, the inflow holes 75 are holes formed on both sides of the protrusion 72 of the inclined plate 70. Specifically, multiple inflow holes 75 are formed in such a way that they penetrate the flat plate portions located on both sides of the protrusion 72. For example, the inflow holes 75 are circular holes. Like the inflow holes 74, the inflow holes 75 allow exhaust gas to flow into the injection space R of the injection unit 40. Since the inflow holes 74 and 75 are located on both sides of the protrusion 72, contact between the exhaust gas passing through the inflow holes 74 and 75 and the urea solution sprayed by the injection unit 40 can be suppressed. As a result, the urea solution easily adheres to the protrusion 72.

[0042] like Figure 3 As shown, a counter plate 80 is provided in the exhaust passage 20 on the downstream side of the inclined plate 70, facing the inclined plate 70. The counter plate 80 is located downstream of the injection section 40 in the exhaust passage 20. The counter plate 80 and the inclined plate 70 form a spray space R for spraying urea water. The lower part of the counter plate 80, like the lower part of the inclined plate 70, is separated from the inner wall surface of the exhaust passage 20.

[0043] The exhaust gas flowing into the injection space R between the opposing plate 80 and the inclined plate 70 heats the urea solution sprayed by the injection section 40. This promotes the evaporation and decomposition of the urea solution. Furthermore, the ammonia gas generated from the evaporation and decomposition of the urea solution by the exhaust gas is directed towards the SCR device 50 downstream of the opposing plate 80.

[0044] The opposing plate 80 is flat. Unlike the inclined plate 70, the opposing plate 80 is not inclined; it is arranged vertically along the vertical direction. Figure 2 As shown, an outlet orifice 81 is provided at the lower part of the opposing plate 80. The outlet orifice 81 is a hole that penetrates the opposing plate 80. For example, the outlet orifice 81 is a circular hole. The outlet orifice 81 allows ammonia gas generated from urea solution and exhaust gas to flow out from the injection space. Thus, the ammonia gas and exhaust gas flow to the SCR device 50 located downstream of the exhaust passage 20, thereby purifying the NO in the exhaust gas. x .

[0045] Since the inflow hole 74 is located on the upper part of the inclined plate 70 and the outflow hole 81 is located on the lower part of the opposing plate 80, therefore... Figure 7 As shown, the distance the exhaust gas flows through the injection space from the inlet orifice 74 increases. That is, the time the exhaust gas remains in the injection space increases. As a result, the heating of urea water passing through the exhaust gas and the delivery of ammonia gas passing through the exhaust gas can be carried out efficiently.

[0046] like Figure 2 As shown, the connecting plate 83 is connected to the lower part of the back surface of the inclined plate 70. Specifically, the connecting plate 83 is arranged parallel to the inclined plate 70 and is connected to both sides of the recess 73 of the inclined plate 70. The connecting plate 83 and the inclined plate 70 form a space for exhaust flow (specifically, Figure 2 (The gap 77 shown). By providing the connecting plate 83, the exhaust flowing through the recess 73 passes through the gap 77 and easily flows into the space between the inclined plate 70 and the exhaust passage 20 (specifically, Figure 7 (Flow below the lower plate 86 shown).

[0047] Connecting plate 83 is semi-circular in shape here. For example... Figure 5 As shown, the lower part of the connecting plate 83 contacts the inner wall surface of the exhaust passage 20. A through hole 84 is provided on the connecting plate 83 to allow exhaust gas flowing below the inclined plate 70 to pass through. The through hole 84 is located on the lower part of the connecting plate 83, below the lower plate 86, and connected to the inner wall surface.

[0048] like Figure 3 As shown, the lower plate 86 is connected to the lower part of the opposing surface of the inclined plate 70 and the lower part of the opposing plate 80. The lower plate 86 is flat. The lower plate 86 is arranged orthogonally to the opposing plate 80. The lower plate 86, together with the inclined plate 70 and the opposing plate 80, forms the spray space R. By providing the lower plate 86, the urea solution sprayed by the spray unit 40 easily adheres to the upper surface of the lower plate 86. For example, urea solution flowing along the opposing surface of the inclined plate 70 easily remains on the upper surface of the lower plate 86.

[0049] like Figure 3 As shown, the lower plate 86 forms a gap with the inner wall surface of the exhaust passage 20. Therefore, as Figure 7 As shown, exhaust gas passes below the lower plate 86 (specifically, the gap between the lower plate 86 and the inner wall of the exhaust passage 20). The exhaust gas passing below the lower plate 86 causes the urea water remaining on the upper surface of the lower plate 86 to evaporate and decompose. As a result, the residue of unevaporated and undecomposed urea water in the urea water sprayed by the injection section 40 can be suppressed.

[0050] Furthermore, while a lower plate 86 is provided as described above, it is not a limitation. For example, if the lower part of the inclined plate 70 is connected to the opposing plate 80, the lower plate 86 may not be provided. Additionally, a connecting plate 83 is provided on the back of the inclined plate 70, but it may not be provided at all.

[0051] <Effects in this implementation> The exhaust treatment device 1 of the above embodiment has, within the exhaust passage 20: an inclined plate 70, which is inclined relative to an imaginary plane orthogonal to the spray direction of the urea water sprayed by the spraying part 40; and an opposing plate 80, which is disposed downstream of the inclined plate 70 in a manner opposite to the inclined plate 70, and forms a spray space for spraying urea water with the inclined plate 70. The inclined plate 70 has: a protrusion 72 formed on the opposing surface opposite to the spraying part 40, to which urea water is sprayed; and a recess 73 formed on the back surface opposite to the opposing surface, forming an exhaust flow path.

[0052] By providing a protrusion 72 on the opposing surface of the inclined plate 70, the surface area on which the urea water sprayed by the spraying section 40 adheres in the opposing surface can be increased. Furthermore, by providing a recess 73 on the back surface of the inclined plate 70 to form an exhaust flow path, the exhaust flow is concentrated in the recess 73, which easily heats the recess 73, thus promoting the evaporation and decomposition of the urea water adhering to the protrusion 72. In particular, since a large amount of urea water easily adheres to the protrusion 72, the evaporation and decomposition of the urea water can be efficiently promoted with a simple structure.

[0053] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and alterations can be made within its scope. For example, all or part of the device can be functionally or physically distributed or integrated in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of new embodiments resulting from combinations are the same as the effects of the original embodiments.

Claims

1. An exhaust gas treatment device, characterized in that, include: The exhaust passage for exhaust flow; A spray nozzle that sprays urea water into the exhaust passage; An inclined plate is inclined relative to an imaginary plane within the exhaust passage, and the imaginary plane is orthogonal to the injection direction of the urea water being injected by the injection unit. as well as An opposing plate is disposed in the exhaust passage downstream of the inclined plate, opposite to the inclined plate, and forms a spray space with the inclined plate for spraying the urea solution. The inclined plate has the following characteristics: A protrusion is formed on an opposing surface opposite to the spray section, and the urea solution is sprayed onto the protrusion; and A recess is formed on the back side opposite to the opposing surface, and forms the flow path for the exhaust gas.

2. The exhaust gas treatment device as described in claim 1, characterized in that, The recess is formed directly behind the protrusion.

3. The exhaust gas treatment device as described in claim 1, characterized in that, The protrusion is located directly below the jet.

4. The exhaust gas treatment device as described in claim 1, characterized in that, The convex portion and the concave portion are formed in the center of the inclined plate from the bottom to the top.

5. The exhaust gas treatment device as described in claim 1, characterized in that, The protrusions and the recesses are formed by bending a flat plate.

6. The exhaust gas treatment device as described in claim 1, characterized in that, The lower part of the inclined plate is separated from the inner wall of the exhaust passage. The exhaust treatment device further includes a connecting plate, which is connected to the lower part of the inclined plate and forms a space for the exhaust flow with the inclined plate.

7. The exhaust gas treatment device as described in claim 1, characterized in that, In the upper part of the inclined plate, inflow holes are provided on both sides of the protrusion to allow the exhaust gas to flow into the injection space.

8. The exhaust gas treatment apparatus as described in claim 7, characterized in that, An outlet hole is provided at the lower part of the opposing plate, which allows the ammonia gas generated by the urea water and the exhaust gas to flow out from the injection space.

9. The exhaust gas treatment device as described in claim 1, characterized in that, The lower part of the inclined plate and the lower part of the opposing plate are separated from the inner wall surface of the exhaust passage. The exhaust treatment device further includes a lower plate, which is connected to the lower part of the inclined plate and the lower part of the opposing plate, and forms a gap between the lower plate and the inner wall surface.

10. The exhaust gas treatment apparatus as described in claim 9, characterized in that, The exhaust treatment device further includes a connecting plate, which is connected to the lower part of the back surface of the inclined plate and forms a space for exhaust flow with the lower part. The exhaust passage is formed in the lower part of the connecting plate, which is located below the lower plate and connected to the inner wall surface.

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