JP6636907B2 - Exhaust gas purification device - Google Patents

Description

  The present disclosure relates to an exhaust gas purification device.

  For the purpose of complying with regulations on exhaust gas components of an internal combustion engine, an exhaust gas purification device is installed in an exhaust gas pipe of the internal combustion engine. In the case of a diesel engine, an exhaust gas purifying device such as a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and a catalyst for selective catalytic reduction (SCR) is used in combination in the exhaust gas purifying device.

  Among these exhaust gas purifying members, an SCR catalyst (hereinafter, also referred to as a “reduction catalyst”) is generally installed downstream of another catalyst or a filter. SCR is a method in which NOx in exhaust gas is reduced by a reducing agent and a reducing catalyst to reform harmless nitrogen.

  In the SCR, in order to make the reduction catalyst function efficiently and improve the purification rate of the exhaust gas, it is necessary to mix the reducing agent and uniformly disperse it in the exhaust gas, and to uniformly distribute the exhaust gas containing the reducing agent. It is necessary to make contact with the reduction catalyst.

  Therefore, there has been proposed an exhaust gas purifying apparatus in which a pressure adjusting plate is arranged in a flow path of exhaust gas to generate a swirling flow to diffuse a reducing agent (see Patent Document 1).

JP 2013-15099 A

  In the exhaust gas purification device of Patent Document 1, it is described that a swirl flow can be generated with a simple configuration, but the position where the swirl flow occurs is limited to the vicinity of the cap member. Therefore, there is room for improvement in the diffusion effect of the reducing agent in the exhaust gas.

  An object of one aspect of the present disclosure is to provide an exhaust gas purification device that is excellent in exhaust gas purification efficiency by improving a reducing agent diffusion effect.

  One embodiment of the present disclosure is an exhaust gas purification device for an internal combustion engine. The exhaust gas purification device includes an exhaust gas purification unit, a reduction unit, a communication pipe, and a reducing agent supply unit. The exhaust gas purification unit reforms or collects environmental pollutants in the exhaust gas. The reduction unit is provided downstream of the exhaust gas purification unit in the flow direction of the exhaust gas, and reduces the exhaust gas in the presence of a reducing agent. The communication pipe communicates the exhaust gas purification unit and the reduction unit. The reducing agent supply unit supplies a reducing agent to the exhaust gas in the communication pipe. The communication pipe is connected to an exhaust port of the exhaust gas purifying unit so as to bend the flow direction of the exhaust gas discharged from the exhaust gas purifying unit, and includes one or more partition plates that divide the flow of the exhaust gas. Have inside. The one or more partition plates are arranged so that at least a part thereof overlaps with the discharge port when viewed from the flow direction of the exhaust gas at the discharge port of the exhaust gas purification unit, and generates at least two swirling flows downstream thereof. . The cross-sectional area of the flow path of the exhaust gas decreases from the exhaust gas purification section toward the communication pipe and increases from the communication pipe toward the reduction section.

  According to such a configuration, the reducing agent can be mixed by the change in the flow direction of the exhaust gas by the communication pipe and the generation of two or more swirling flows by the partition plate disposed inside the communication pipe. Further, the partition plate is disposed so as to overlap with the outlet of the exhaust gas purifier when viewed from the flow direction of the exhaust gas. Therefore, two or more swirling flows generated in the vicinity of the outlet of the exhaust gas purifying section flow to the downstream side while colliding with each other. Further, the cross-sectional area of the flow path of the exhaust gas decreases from the exhaust gas purifying section toward the communication pipe, so that the swirling speed of the swirling flow in the communication pipe is increased. Therefore, the reducing agent supplied into the communication pipe is effectively diffused.

Further, since the cross-sectional area of the flow path of the exhaust gas increases toward the reduction unit, the speed of the exhaust gas is reduced and the exhaust gas is diffused in the reduction unit, so that the bias of the exhaust gas is suppressed.
As a synergistic effect of these, the purification efficiency of the exhaust gas is enhanced.

  In one aspect of the present disclosure, one or a plurality of partition plates may be provided with one partition plate that is disposed so that one surface thereof faces the outlet of the exhaust gas purification unit. According to such a configuration, two or more swirling flows can be easily and reliably generated, and the effect of diffusing the reducing agent is promoted.

  In one aspect of the present disclosure, the partition plate may be a band-shaped flat plate extending in the flow direction of the exhaust gas in the communication pipe and having a width increasing toward the downstream side. According to such a configuration, a swirling flow can be generated from a more upstream side.

  According to one aspect of the present disclosure, the communication pipe may have an impact plate in which the reducing agent collides. Further, the reducing agent supply unit may spray the reducing agent toward the collision plate. According to such a configuration, the reducing agent can be added to the swirling flow after being atomized by the collision plate, so that the effect of diffusing the reducing agent is further improved.

  In one aspect of the present disclosure, the reduction unit may be disposed below the exhaust gas purification unit. Further, the communication pipe may extend in the up-down direction so as to connect the exhaust port of the exhaust gas purification unit and the exhaust gas inlet of the reduction unit. Further, the exhaust gas purifying section, the communication pipe, and the reducing section may form a flow path having a U-shape as viewed from the horizontal direction. According to such a configuration, the size of the exhaust gas purification device can be reduced.

1A is a schematic perspective view of the exhaust gas purification device of the embodiment, and FIG. 1B is a schematic partially transparent perspective view of the exhaust gas purification device of FIG. 1A. FIG. 2 is a cross-sectional view taken along line II-II of the exhaust gas purifying apparatus of FIG. 1A. FIG. 3 is a sectional view taken along line III-III of the exhaust gas purifying apparatus of FIG. 1A. FIG. 4 is a cross-sectional view of the exhaust gas purification device of FIG. 1A taken along line IV-IV. FIG. 5 is a schematic perspective view of a partition plate and a collision plate of the exhaust gas purification device of FIG. 1A. 6A is a schematic diagram showing streamlines of exhaust gas in the cross-sectional view of FIG. 4, and FIG. 6B is a schematic diagram showing streamlines of exhaust gas near the outlet of the exhaust gas purification unit in the perspective view of FIG. 1A. FIG. 6C is a schematic diagram showing streamlines of exhaust gas in the communication pipe in the cross-sectional view of FIG.

Hereinafter, embodiments to which the present disclosure is applied will be described with reference to the drawings.
[1. First Embodiment]
[1-1. Constitution]
The exhaust gas purifying device (hereinafter, also simply referred to as “purifying device”) 1 shown in FIGS. 1A, 1B, 2, 3 and 4 is provided in an exhaust gas pipe of an internal combustion engine, and Reduce environmental pollutants. The purification device 1 includes an exhaust gas purification unit 2, a reduction unit 3, a communication pipe 4, and a reducing agent supply unit 5.

  The internal combustion engine provided with the purification device 1 is not particularly limited, but the purification device 1 can be particularly suitably used as an exhaust gas purification device for a diesel engine. Examples of the diesel engine include those used for driving or power generation in transportation equipment such as automobiles, railways, ships, and construction machines, and power generation facilities.

<Exhaust gas purification section>
The exhaust gas purification unit 2 reforms or collects environmental pollutants in the exhaust gas. Here, "environmental pollutants" mean carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), sulfur oxides (SOx), hydrocarbons (HC), and the like.

  As shown in FIG. 2, the exhaust gas purifying unit 2 includes a purifying member 21 for purifying the exhaust gas, and a cylindrical casing 22 containing the purifying member 21. The exhaust gas flows along the center axis direction of the casing 22 (the X-axis direction in the figure) while contacting the purification member 21 inside the casing 22.

  Examples of the cleaning member 21 include a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), and a NOx adsorbent. DOC is a catalyst that oxidizes soluble organic components (SOF), CO, and HC in PM contained in exhaust gas. The DPF is a filter that traps PM contained in the exhaust gas. The NOx adsorbent is a substance that adsorbs and removes NOx.

  As the cleaning member 21, a tubular body having a honeycomb structure is generally used. As the exhaust gas passes through the inside of the honeycomb structure, environmental pollutants in the exhaust gas are reformed by the catalyst metal included in the purification member 21 or captured by the purification member 21.

  In the present embodiment, the exhaust gas purifying unit 2 is arranged such that the flow direction of the exhaust gas inside is horizontal, that is, the central axis of the cylindrical casing 22 is horizontal. The exhaust gas outlet 2A of the exhaust gas purifying section 2 is formed so that the exhaust gas is discharged in a horizontal direction (X-axis direction in the figure). The diameter of the discharge port 2A is smaller than the inner diameter of a portion of the casing 22 in which the purifying member 21 is stored.

  In this specification, for the sake of convenience, as shown in FIG. 2, the flow direction of the exhaust gas at the outlet 2A of the exhaust gas purifying unit 2 is referred to as a "first direction D1". This first direction D1 is a direction parallel to the X axis in the figure.

<Reduction part>
The reducing unit 3 reduces the exhaust gas in the presence of a reducing agent. Specifically, the reducing unit 3 reduces NOx in the exhaust gas with ammonia and a reducing catalyst, and reforms the exhaust gas into harmless nitrogen. Ammonia as a reducing agent is generally generated by injecting urea water into exhaust gas and hydrolyzing urea in the urea water.

  The reduction unit 3 includes a reduction catalyst 31 and a cylindrical casing 32 that houses the reduction catalyst 31. The reduction catalyst 31 includes a base material such as a ceramic and a metal catalyst supported on the base material. The exhaust gas flows along the center axis direction of the casing 32 while contacting the reduction catalyst 31 inside the casing 32.

  In the present embodiment, the reduction unit 3 is arranged such that the flow direction of the exhaust gas inside is horizontal, that is, the central axis of the cylindrical casing 32 is horizontal. The reducing unit 3 is provided downstream of the exhaust gas purifying unit 2 in the flow direction of the exhaust gas. In the present embodiment, as shown in FIG. 3, the reducing unit 3 is disposed so as to overlap below the exhaust gas purifying unit 2. In other words, the reducing unit 3 is vertically juxtaposed with the exhaust gas purifying unit 2 so that the central axes of the casing 22 of the exhaust gas purifying unit 2 and the casing 32 of the reducing unit 3 are parallel to each other.

  In this specification, for the sake of convenience, the flow direction of the exhaust gas in the reducing unit 3 is referred to as a “third direction D3” as shown in FIG. The third direction D3 is opposite to the first direction D1, and is a direction parallel to the X axis in the drawing.

  Further, the reduction unit 3 has a hollow front region 3 </ b> A in which the reduction catalyst 31 is not stored in a part of the casing 32. The front region 3A is provided on the side of the reduction unit 3 to which the communication pipe 4 is connected. In the front region 3A, an exhaust gas inlet 3B is formed above the peripheral surface of the casing 32. The diameter of the inlet 3B is smaller than the inner diameter of the portion of the casing 32 in which the reduction catalyst 31 is stored.

<Communication pipe>
The communication pipe 4 connects the exhaust gas purification unit 2 and the reduction unit 3. That is, the exhaust gas discharged from the exhaust gas purification unit 2 is introduced into the reduction unit 3 through the communication pipe 4. In this specification, for the sake of convenience, the flow direction of the exhaust gas in the communication pipe 4 is referred to as a “second direction D2”.

  The communication pipe 4 has therein one partition plate 6 for dividing the flow of the exhaust gas and one collision plate 7 for diffusing the reducing agent. The communication pipe 4 is connected to the outlet 2A of the exhaust gas purification unit 2 so as to bend the flow direction of the exhaust gas discharged from the exhaust gas purification unit 2 from the first direction D1 to the second direction D2.

  In the present embodiment, the communication pipe 4 extends in the up-down direction (the Z-axis direction in the figure) so as to connect the outlet 2A of the exhaust gas purification unit 2 and the exhaust gas inlet 3B of the reduction unit 3. I have. At the upper end of the communication pipe 4, a reducing agent supply unit 5 described below is installed. An opening connected to the outlet 2A of the exhaust gas purification unit 2 is provided near the upper end of the side surface of the communication pipe 4 facing the exhaust gas purification unit 2. The lower end of the communication pipe 4 is connected to the inlet 3 </ b> B of the reduction unit 3.

  The communication pipe 4 is formed such that the width in the first direction D1 (X-axis direction in the drawing) is smaller than the width in the direction orthogonal to the first direction D1 (Y-axis direction in the drawing). That is, the cross section of the communication pipe 4 in the second direction D1 is an elliptical shape or a rectangular shape whose short axis is parallel to the X axis and whose long axis is parallel to the Y axis. However, the sectional shape of the communication pipe 4 is not particularly limited as long as two or more swirling flows can be created by the partition plate 6. The cross-sectional area of the communication pipe 4 in the second direction D2 is smaller than the cross-sectional area of the inside of the casing 21 of the exhaust gas purifying section 2 and the cross-sectional area of the front section 3A of the reducing section 3 in the third direction D3.

(Partition plate)
The partition plate 6 generates at least two swirling flows on the downstream side by dividing the flow of the exhaust gas. As shown in FIG. 4, the partition plate 6 is disposed inside the communication pipe 4 such that at least a part thereof overlaps the discharge port 2A when viewed from the first direction D1 (X-axis direction in the figure).

  In the present embodiment, the partition plate 6 is arranged such that one surface thereof faces the outlet 2A of the exhaust gas purifying unit 2. Further, the partition plate 6 is arranged such that the surface thereof is orthogonal to the first direction D1. Further, the partition plate 6 is disposed so as to overlap the center of the outlet 2A when viewed from the first direction D1.

  As shown in FIGS. 4 and 5, the partition plate 6 is a band-shaped flat plate that extends in the second direction D2 (that is, the vertical direction) and increases in width toward the downstream side in the exhaust gas flow direction. Further, as shown in FIG. 4, the width of the partition plate 6 is smaller than the diameter of the outlet 2A. Therefore, when viewed from the first direction D1, the discharge port 2A has regions on both left and right sides that do not overlap with the partition plate 6, that is, flow paths that do not collide with the partition plate 6.

  The length of the partition plate 6 in the up-down direction (the Z-axis direction in the drawing) is larger than the diameter of the outlet 2A of the exhaust gas purifying unit 2. The upper end of the partition plate 6 is located above the upper end of the outlet 2A. Therefore, the partition plate 6 is disposed so as to extend from above the outlet 2A to below when viewed from the first direction D1.

(Collision plate)
The collision plate 7 diffuses the reducing agent sprayed from the reducing agent supply unit 5. The collision plate 7 is arranged so as to face the spray hole of the injector of the reducing agent supply unit 5.

  In the present embodiment, the collision plate 7 is installed near the upper end of the communication pipe 4 in a direction in which the surface is parallel to the horizontal direction. Further, as shown in FIG. 4, the collision plate 7 is disposed at a position overlapping with the outlet 2 </ b> A of the exhaust gas purification unit 2 when viewed from the first direction D <b> 1.

  Note that the shape and size of the collision plate 7 can be appropriately changed according to the position and configuration of the injector of the reducing agent supply unit 5. Further, as shown in FIG. 5, the collision plate 7 may be provided with one or a plurality of through holes. Further, a plurality of collision plates may be arranged in the communication pipe 4 in combination.

<Reducing agent supply section>
The reducing agent supply unit 5 supplies a reducing agent to the exhaust gas in the communication pipe 4. The reducing agent supply unit 5 has an injector that sprays the reducing agent toward the collision plate 7. 1A, 1B, 2 and 4, only the connecting pipe to the communication pipe 4 is shown as the reducing agent supply section 5, and members such as injectors are not shown.

  In the present embodiment, the reducing agent supply unit 5 is connected to the upper end of the communication pipe 4 and is configured to spray urea water as a reducing agent downward. A known injector can be used as the injector of the reducing agent supply unit 5.

<Exhaust gas flow path>
As shown in FIG. 2, the exhaust gas discharged from the exhaust gas purification unit 2 is discharged from the discharge port 2A in the first direction D1, and then the flow direction is bent in the second direction D2 by the communication pipe 4. Further, after moving in the communication pipe 4, the exhaust gas is introduced into the upstream region 3 </ b> A of the reduction unit 3, further changes the flow direction in the third direction D <b> 3, and passes through the reduction unit 3. That is, in the purification device 1, the exhaust gas purification unit 2, the communication pipe 4, and the reduction unit 3 form a U-shaped 90 ° rotation, and a channel that is turned sideways when viewed from the horizontal direction.

  Further, the cross-sectional area of the flow path of the exhaust gas (that is, the area of the flow path in a cross section perpendicular to the flow direction of the exhaust gas) decreases from the exhaust gas purification unit 2 toward the communication pipe 4, and decreases from the communication pipe 4. It is configured to increase toward the reduction unit 3. The cross-sectional area of the flow path of the exhaust gas in the reduction unit 3 (that is, the cross-sectional area inside the casing 32) is the cross-sectional area of the flow path of the exhaust gas in the exhaust gas purification unit 2 (that is, the cross-sectional area inside the casing 22). Greater than.

[1-2. function]
Next, the generation mechanism of the swirling flow in the purification device 1 will be described.
In the purification device 1, after the exhaust gas discharged from the exhaust gas purification unit 2 enters the communication pipe 4, the flow is divided into two right and left parts by the partition plate 6. The two divided flows flow so as to go around the back side of the partition plate 6, respectively. Thereby, two swirling flows are formed in the communication pipe 4 as shown in FIGS. 6A, 6B, and 6C. The two swirling flows swirl in opposite directions about an axis (Z-axis) parallel to the second direction D2. The two swirling flows flow downstream (that is, downward) while colliding. That is, the exhaust gas is bent from the first direction D1 to the second direction D2 after the swirling flow is formed by the partition plate 6. In FIGS. 6A, 6B, and 6C, the streamline is displayed darker as the flow rate of the exhaust gas is higher.

  Here, since the cross-sectional area of the flow path of the exhaust gas in the communication pipe 4 is smaller than the cross-sectional area of the flow path of the exhaust gas in the exhaust gas purification unit 2, the flow rate of the exhaust gas in the communication pipe 4 increases. Therefore, as shown in FIGS. 6A and 6B, the swirling flow swirls at a relatively high speed in the central portion of the communication pipe 4, thereby promoting the diffusion of the reducing agent.

  The exhaust gas that has flowed while swirling to the lower end of the communication pipe 4 is introduced into the upstream region 3 </ b> A of the reduction unit 3. The flow path of the exhaust gas in the front region 3A has a larger cross-sectional area than the flow path in the communication pipe 4. Therefore, as shown in FIG. 6A, the exhaust gas introduced into the preceding region 3A decreases in flow velocity and diffuses into the preceding region 3A. As a result, a new swirling flow swirling around the axis (X-axis) parallel to the third direction D3 is formed in the front region 3A, and the diffusion of the reducing agent is promoted.

[1-3. effect]
According to the embodiment described in detail above, the following effects can be obtained.
(1a) Two swirling flows are generated near the outlet 2A of the exhaust gas purification unit 2 by the partition plate 6 arranged in the communication pipe 4 so as to overlap the outlet 2A of the exhaust gas purification unit 2. These two swirling flows flow to the downstream side in the communication pipe 4 while colliding with each other. The swirling flow allows the reducing agent to be effectively diffused into the exhaust gas.

  (1b) Since the cross-sectional area of the flow path of the exhaust gas decreases from the exhaust gas purifying section 2 toward the communication pipe 4, the swirling speed of the swirling flow in the communication pipe 4 is increased. Thereby, the reducing agent is effectively diffused.

  (1c) Since the cross-sectional area of the flow path of the exhaust gas increases toward the reduction unit 3, the speed of the exhaust gas is reduced and diffused in the reduction unit 3, and the unevenness of the exhaust gas is suppressed. Therefore, the catalyst comes into uniform contact with the reduction catalyst 31 and the reduction is performed efficiently.

  (1d) Since the partition plate 6 is a band-shaped flat plate whose width increases toward the downstream side, a swirling flow can be generated from the more upstream side. Thereby, the diffusion effect of the reducing agent is promoted.

  (1e) Since the communication pipe 4 has the collision plate 7 for diffusing the reducing agent therein, the reducing agent can be atomized by spraying the reducing agent toward the collision plate 7. The atomized reducing agent is effectively diffused by the swirling flow.

  Further, the urea water that has not been evaporated even when supplied into the exhaust gas adheres to the collision plate 7, so that the urea water can be heated and evaporated by the collision plate 7. Therefore, the supply efficiency of the urea water can be improved.

  (1f) Since the exhaust gas purifying unit 2, the communication pipe 4, and the reducing unit 3 form a flow path having a U-shape as viewed from the horizontal direction, the purifying device 1 can be designed compact. Therefore, for example, it can be suitably disposed immediately below the engine of the vehicle.

[2. Other Embodiments]
As described above, the embodiments of the present disclosure have been described, but it is needless to say that the present disclosure is not limited to the above-described embodiments, and can take various forms.

  (2a) In the exhaust gas purification device 1 of the above embodiment, if the communication pipe 4 is connected to the outlet 2A so as to bend the flow direction of the exhaust gas discharged from the exhaust gas purification unit 2, the exhaust gas purification unit 2 The positional relationship between and the reduction unit 3 is not limited. Further, it is not always necessary to configure the flow path in a shape in which the U-shape is turned down when viewed from the horizontal direction.

  Therefore, the reducing unit 3 may be arranged on the exhaust gas purifying unit 2, or the exhaust gas purifying unit 2 and the reducing unit 3 may be arranged at the same height. Further, the extending direction of the communication pipe 4 is not limited to the vertical direction (that is, the vertical direction), and may be a horizontal direction or an oblique direction combining the vertical direction and the horizontal direction. Further, the flow direction of the exhaust gas may be bent three or more times.

  (2b) In the exhaust gas purifying apparatus 1 of the above embodiment, the number of swirling flows generated by the partition plate 6 may be three or more. The shape and direction of the partition plate 6 are not limited as long as at least two swirling flows can be generated in the communication pipe 4.

  Therefore, the partition plate 6 does not necessarily need to be a band-shaped flat plate whose width increases toward the downstream side. The partition plate 6 may have a constant width, or may be a curved or bent plate. In addition, the partition plate 6 does not necessarily need to have one surface facing the outlet 2A of the exhaust gas purification unit 2, and may be arranged so that the surface is parallel to the first direction D1. Further, a swirling flow may be generated by combining a plurality of partition plates 6.

  (2c) In the exhaust gas purifying apparatus 1 of the above embodiment, the mounting position of the reducing agent supply unit 5 is not limited to the upper end of the communication pipe 4. The reducing agent supply unit 5 can be attached to an arbitrary position of the communication pipe 4. Accordingly, the reducing agent supply direction of the reducing agent supply unit 5 (that is, the spray direction) can be arbitrarily designed.

  (2d) In the exhaust gas purifying apparatus 1 of the above embodiment, the collision plate 7 is not an essential component, and may be omitted depending on the function of the injector of the reducing agent supply unit 5. Alternatively, the partition plate 6 may be used as the collision plate 7, and the partition plate 6 may be sprayed with a reducing agent and collided.

  (2e) The functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, a part of the configuration of the above embodiment may be omitted. Further, at least a part of the configuration of the above-described embodiment may be added to or replaced with the configuration of another above-described embodiment. Note that all aspects included in the technical idea specified by the language described in the claims are embodiments of the present disclosure.

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification apparatus, 2 ... Exhaust gas purification part, 2A ... Discharge port, 3 ... Reduction part,
3A: front region, 3B: inlet, 4: communication pipe, 5: reducing agent supply unit, 6: partition plate,
7: collision plate, 21: purification member, 22: casing, 31: reduction catalyst,
32 ... casing.

Claims (5)

An exhaust gas purification device for an internal combustion engine,
An exhaust gas purification unit that reforms or collects environmental pollutants in the exhaust gas,
A reducing unit that is provided downstream of the exhaust gas purifying unit in the flow direction of the exhaust gas and reduces the exhaust gas in the presence of a reducing agent;
A communication pipe communicating the exhaust gas purification unit and the reduction unit,
A reducing agent supply unit that supplies a reducing agent to the exhaust gas in the communication pipe;
With
The communication pipe is connected to an outlet of the exhaust gas purification unit so as to bend a flow direction of the exhaust gas discharged from the exhaust gas purification unit, and one or more of the communication pipes divide the flow of the exhaust gas. Having a partition plate inside,
The one or more partition plates overlap at least a part of the exhaust gas when viewed from a flow direction of the exhaust gas at the exhaust port of the exhaust gas purification unit, and generate at least two swirling flows downstream thereof. Arranged to let
The cross-sectional area of the flow path of the exhaust gases, with reduced from the exhaust gas purification unit toward the communicating pipe, Ri Na largely from the communication pipe toward the reduction unit,
The communication pipe has a circular opening connected to the exhaust port of the exhaust gas purification unit,
An exhaust gas purification device , wherein at least a part of the one or more partition plates is arranged to overlap the opening of the communication pipe when viewed from a flow direction of the exhaust gas at the exhaust port . The exhaust gas purification device according to claim 1,
An exhaust gas purification device, comprising: one or more of the one or more partition plates, one of which is disposed so that one surface thereof faces the outlet of the exhaust gas purification unit. The exhaust gas purification device according to claim 2,
The exhaust gas purifying device, wherein the partition plate is a band-shaped flat plate extending in a flow direction of the exhaust gas in the communication pipe and increasing in width toward a downstream side. The exhaust gas purification device according to any one of claims 1 to 3, wherein
The communication pipe has a collision plate for causing the reducing agent to collide therein,
The exhaust gas purifying device, wherein the reducing agent supply unit sprays the reducing agent toward the collision plate. The exhaust gas purifying apparatus according to any one of claims 1 to 4, wherein
The reduction unit is disposed below the exhaust gas purification unit,
The communication pipe extends vertically so as to connect the exhaust port of the exhaust gas purification unit and the exhaust gas introduction port of the reduction unit,
An exhaust gas purifying apparatus, wherein the exhaust gas purifying unit, the communication pipe, and the reducing unit form a flow path in a shape of a U-shape viewed from a horizontal direction.