JP5737618B2 - Exhaust gas purification device for internal combustion engine - Google Patents

Description

  The present invention relates to an exhaust gas purification apparatus that renders a pollutant contained in exhaust gas of an internal combustion engine harmless by supplying an additive and using a catalyst device provided in an exhaust system.

An exhaust system of a diesel engine that is an internal combustion engine (hereinafter referred to as an engine) includes diesel exhaust particulates (hereinafter referred to as “PM (Particulate Matter)”) that are contained in exhaust gas discharged from the engine and are harmful substances. NOx (nitrogen oxide) is contained, and PM is supplemented by a diesel particulate filter (hereinafter referred to as “DPF (Diesel Particulate Filter)”). For NOx, urea water is added to the exhaust gas, and the urea water is hydrolyzed to generate NH ₃ (ammonia). Using the generated NH ₃ , NOx is selectively reduced and purified by a selective reduction catalyst. , Reduced to N ₂ (nitrogen) and H ₂ O (water) and rendered harmless.

In order to purify NOx in the exhaust gas using the additive, urea water (hereinafter referred to as “urea water”), which is the injected additive, is mixed well with the exhaust gas and diffused evenly. Atomization is an element that enables efficient purification. When these conditions are satisfied, urea water is evenly supplied to each part of the catalyst device, and high purification performance is realized.
In order to satisfy these conditions, various measures have been implemented in the past.
I. Promotes diffusion, mixing, and atomization of additives through the use of turbulence.
II. By increasing the channel length after the additive is added, the time for diffusion, mixing, and atomization of the additive is increased.
The two types are the main ones.

  For example, in Japanese Patent Application Laid-Open No. 2009-24629 (Patent Document 1) of our application, a venturi-shaped mixing chamber is provided upstream of the SCR catalyst in the exhaust passage, and a swirling flow is generated at the most upstream position in the mixing chamber. There is a technical disclosure that promotes mixing with urea water by disposing a fin device and utilizing the turbulence by making the exhaust gas swirl with the fin device.

  Japanese Patent Laid-Open No. 2008-215286 (Patent Document 2) also discloses that the particulate filter at the entrance end of the mixing pipe also has a first opening at a position close to the exit side and a position far from the exit side. Forms a second opening that diametrically opposes the first opening and guides the flow so that all exhaust gas from the particulate filter swirls around the inlet end of the mixing pipe in one direction The first partition plate, the second partition plate that bisects the flow of the exhaust gas induced by the first partition plate and introduces the flow inside the swirl direction from the tangential direction to the first opening, and the remaining swirl direction By providing a third partition plate in the downstream end of the gas collecting chamber for introducing the outer flow from the tangential direction with respect to the second opening, the turbulence is utilized and the mixing distance = mixing time is taken. And a technique for improving the mixing ability of urea water.

JP 2009-24629 A JP 2008-215286 A

However, according to Patent Document 1, since the venturi-like mixing chamber is provided on the upstream side of the SCR catalyst in the exhaust system path, the entire purification device becomes long in the exhaust system path.
On the other hand, according to Patent Document 2, a casing A in which a particulate filter is held, a gas collecting chamber connected to the outlet side of the casing A and causing the above-described exhaust gas to swirl, and the gas collecting chamber A mixing pipe that is connected and disposed substantially parallel to the axis of the casing A, and a gas dispersion chamber is connected to the outlet side of the mixing pipe, and is connected to the gas dispersion chamber and disposed substantially parallel to the axis of the mixing pipe. Since the entire selective purification apparatus is short in the exhaust passage system, the entire outer shape is thick because the casing B holding the provided selective catalytic reduction catalyst is folded.
Therefore, in both Patent Documents 1 and 2, in order to secure a distance for mixing exhaust gas and urea water, one is longer and the other is thicker, so that it can be mounted on a vehicle, can be mounted on a vehicle, and the like. Problems may occur.

  Accordingly, the present invention has been made in view of such problems, and an exhaust gas flow passage that rotates the flow of exhaust gas in the circumferential direction around the axis of the exhaust system passage upstream of the catalyst device of the exhaust system passage. By forming a mixing promotion chamber that promotes mixing of exhaust gas and urea water, the exhaust gas and urea water flow in the circumferential direction to ensure a distance for mixing, and the length in the exhaust system direction And reducing the thickness of the entire device to improve the mountability and assembly properties of the exhaust gas purifying device and the suppression of exhaust resistance.

The present invention achieves such an object, and is provided in an exhaust system passage of an internal combustion engine, and a catalyst device for purifying exhaust gas of the internal combustion engine by supplying an additive,
Provided upstream of the catalytic converter of the exhaust system path has an exhaust gas flow path of the exhaust gas around the axis of the exhaust system path flows along the flow of exhaust gas in the circumferential direction, the said gas added A mixing promotion chamber for promoting mixing with the agent;
Provided in the exhaust gas introduction hole near the mixing promotion chamber, and an additive injection means for injecting the additive into the exhaust gas flow passage,
The mixing promotion chamber is disposed in a state of being connected in series along the exhaust system path, and the first mixing promotion chamber is configured so that the circumferential flow of the exhaust gas in the exhaust gas flow path is reversed to each other; A second mixing promotion chamber,
The first mixing promotion chamber is disposed so that a cross section of the first mixing promotion chamber has a J shape, and the center of the curved portion of the J shape includes the axis, A front end is connected to the casing, extends along the axis, is disposed at a back-to-back position with the linear portion, and is sandwiched between the first guide member and the casing, and has a cross-section. The shape is curved in the direction opposite to the curved portion, the second guide member extending along the axis, and the exhaust system upstream side of the casing is closed, and the first guide disposed on the axis. The first upstream lid member having the exhaust gas introduction hole and the exhaust system downstream side of the casing are closed, and disposed on a center line parallel to the axis passing through the curved portion of the second guide member. 1st downstream which has the 1st exhaust gas discharge hole A first exhaust gas flow passage surrounded by the casing, the first guide member, the second guide member, the first upstream lid member, and the first downstream lid member. Forming,
In the second mixing promotion chamber, the first guide member and the second guide member are arranged in the same phase in the circumferential direction of the first mixing promotion chamber with respect to the casing, and close the exhaust gas system upstream side of the casing, A second upstream cover member having a second upstream cover member provided with a second exhaust gas introduction hole at a position opposed to the first exhaust gas discharge hole and a second exhaust gas discharge hole disposed on the axis. Forming a second exhaust gas flow passage surrounded by the casing, the first guide member, the second guide member, the second upstream lid member, and the second downstream lid member,
The first exhaust gas flow path and the second exhaust gas flow path are configured such that the flow of exhaust gas flowing through each of the first exhaust gas flow path and the second exhaust gas flow path is reversed in the circumferential direction.

  In this invention, since the exhaust gas flow passage that rotates in the circumferential direction around the axis of the exhaust system passage is formed, the flow passage length necessary for mixing the exhaust gas and the additive can be secured. The exhaust system direction of the entire exhaust system can be shortened, and the mountability to the vehicle is improved.

In the invention of the present application, the mixing promotion chamber is disposed in a state where the first mixing promotion chamber and the second mixing promotion chamber are connected in series along the exhaust system path. the direction of flow of the exhaust gas flowing through the exhaust gas flow passage is ing reversed by the second mixing promotion chamber.

  By adopting such a configuration, the flow direction of the exhaust gas flowing in the exhaust gas flow passages of the first mixing promotion chamber and the second mixing promotion chamber is reversed, so that the flow of the exhaust gas is disturbed. And, it has the effect of further promoting the mixing of the exhaust gas and the additive.

In the present invention, preferably, the casing is cylindrical.
The first guide member has a straight end fixed to the casing, and extends in the entire axial direction of the casing.
The second guide member may extend over the entire axial direction of the casing .

By adopting such a configuration, since the exhaust gas flow passage through which the exhaust gas flows is in the circumferential direction of the casing, the exhaust gas flow passage length N for promoting the mixing of the additive and the exhaust gas is proportional to the diameter of the casing. Since the exhaust gas flow passage length N can be increased, the axial length of the casing can be shortened, and the overall length of the exhaust gas purification apparatus can be shortened.
In addition to the length of the exhaust gas flow path length N, the flow direction of the exhaust gas is reversed between the first exhaust gas flow path and the second exhaust gas flow path. This has the effect of promoting the mixing of the additive and the exhaust gas.

  In the present invention, preferably, a bell mouth-shaped third guide member for introducing the exhaust gas is disposed in the exhaust gas introduction hole of the mixing promotion chamber.

  With such a configuration, the bellmouth-shaped third guide member is disposed in the exhaust gas introduction hole of the mixing promotion chamber, so that the inflow resistance of the exhaust gas entering the mixing promotion chamber is reduced, and the exhaust pressure in the exhaust manifold section As a result, the engine exhaust resistance is reduced and the engine output is improved and the fuel consumption is reduced.

  In the present invention, preferably, the cross-sectional areas of the exhaust gas introduction hole, the exhaust gas exhaust hole, and the exhaust gas flow passage of each of the first and second mixing promotion chambers hold the mixing promotion chamber. The cross-sectional area of the exhaust pipe connecting portion of the purification device casing may be substantially the same or larger.

  With such a configuration, the cross-sectional areas of the exhaust gas introduction hole, the exhaust gas exhaust hole, and the exhaust gas flow passage of the mixing promotion chamber are substantially equal to the cross-sectional area of the exhaust pipe connection portion of the purifier casing. Or since it enlarged, the increase in the exhaust_gas | exhaustion resistance of waste gas can be suppressed, and the reduction of an engine output can be prevented.

  In the present invention, preferably, the additive injection means for injecting the additive into the first exhaust gas flow passage is installed at an upstream position of the first exhaust gas flow passage and in the first mixing promotion chamber. The first exhaust gas discharge hole may be positioned on the lower side in the direction of gravity, and the first exhaust gas introduction hole may be arranged on the upper side so that the additive is injected in the direction along the flow of the exhaust gas.

  By adopting such a configuration, the additive injection means is disposed above the first exhaust gas discharge hole of the first mixing promotion chamber with the first exhaust gas introduction hole as the center, so that the additive is sufficiently mixed. Even when it cannot be promoted and becomes liquid granular form and stays on the wall of the mixing promotion chamber and the lower side in the gravity direction, it is vaporized by the exhaust gas heat and flows downstream, so that the additive can be used effectively.

  According to the present invention, the mixing promotion chamber is formed with an exhaust gas flow passage that rotates the flow of exhaust gas in the circumferential direction. The cross-sectional areas of the exhaust gas introduction hole, the exhaust gas discharge hole, and the exhaust gas flow passage of the mixing promotion chamber are equal to the cross-sectional area of the exhaust pipe connection portion of the purification device casing that holds the mixing promotion chamber. On the other hand, since the structure is substantially the same or larger, it is possible to suppress an increase in exhaust resistance of exhaust gas, suppress an increase in pumping loss of the engine, and prevent a decrease in engine output.

These show the whole block diagram of the exhaust gas purification apparatus of the diesel engine concerning embodiment of this invention. These show the schematic block diagram of the exhaust gas purification apparatus concerning embodiment of this invention. Is a schematic structural diagram explaining the structure of the mixing promotion chamber, (A) is the first mixing promotion chamber of the present invention, (B) is the second mixing promotion chamber, (C) is a view as viewed from the arrow Z in (A). Show. (A) is a flow path explanatory view of the exhaust gas in the first mixing promotion chamber, (B) is a flow path explanatory view of the exhaust gas in the second mixing promotion chamber. FIG. 3 shows a view corresponding to the Z arrow in FIG.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to specific examples unless otherwise specifically described. Only.

FIG. 1A shows an overall configuration diagram in which the present invention employs an exhaust gas purification device 2 for an engine 1 mounted on a vehicle.
The engine 1 is provided with an exhaust system path 4 and an air supply system path 5. The exhaust system path 4 is supported by an exhaust manifold 4e into which exhaust gas discharged from the combustion chamber of the engine 1 is introduced, and the exhaust gas discharged from the exhaust manifold 4e coaxially with a compressor 4a, which will be described later, and rotationally drives the compressor 4a. An exhaust turbine 4b of the turbocharger 41 that performs the above operation and an exhaust pipe 4d that guides the exhaust gas discharged from the exhaust turbine 4b to the exhaust gas purification device.
On the other hand, the air supply system path 5 is connected to an air cleaner 5e, a compressor 4a that is coaxially connected to the exhaust turbine 4b for supplying air from the air cleaner 5e, and a supply that guides the supplied air to the intercooler 5b. An air pipe 5a, an intercooler 5b that cools the pressurized and heated supply air, an air supply pipe 5c that is cooled by the intercooler 5b and guides the air supply to the intake manifold 5d of the engine 1, and an intake manifold 5d. .
The supply air obtained by burning the fuel in the combustion chamber is discharged to the exhaust manifold 4e as exhaust gas, and the exhaust turbine 4b of the turbocharger 4 is rotated and introduced into the exhaust gas purification device 2 through the exhaust pipe 4d.
Reference numeral 3 denotes an engine control unit (hereinafter abbreviated as “ECU”) that controls the rotational speed of the engine and the injection amount of urea water as an additive according to the engine rotational speed and load.

FIG. 2 is a schematic configuration diagram of the inside of the exhaust gas purification device 2, and the exhaust gas discharged from the high manifold 4 e of the engine 1 is introduced into the casing 21 from the exhaust pipe connection portion 211 of the casing 21.
Inside the casing 21, the upstream oxidation catalyst 22 for removing carbon monoxide (CO) and hydrocarbons (HC) sequentially from the upstream side of the exhaust system passage, and the suspended particulate matter (PM) with a space between the upstream oxidation catalyst 22. ), A bell mouth-shaped third guide member 6 that makes it easy to introduce the exhaust gas that has passed through the DPF 23 at a distance from the DPF 23 into the first mixing promotion chamber 7, and is connected to the third guide member 6. The first mixing promotion chamber 7 according to the present invention for promoting the mixing of the exhaust gas and the urea water as the additive, the second mixing promotion chamber 8 arranged in connection with the first mixing promotion chamber 7, A selective reduction catalyst 24 that selectively reduces NOx to water (H ₂ 0) and nitrogen (N ₂ ) with an interval in the second mixing promotion chamber 8, and a selective reduction catalyst with an interval in the selective reduction catalyst 24 ammonia slip 24 _(NH 3), carbon monoxide (CO) and the downstream side oxidation catalyst for removing hydrocarbons (HC) is arranged.
The purified exhaust gas is discharged from the exhaust gas discharge hole 212 of the casing 21.
In addition, a urea water injection nozzle that is an additive injection means is disposed upstream of the first exhaust gas flow passage 79 (see FIG. 3A) of the first mixing promotion chamber 7.
This is arranged in the upstream portion of the first exhaust gas flow passage 79 in order to make the mixing distance of urea water and exhaust gas as long as possible.

FIG. 3 is a schematic structural diagram for explaining the structure of the mixing promotion chamber. (A) is the first mixing promotion chamber of the present invention, (B) is the second mixing promotion chamber, and (C) is Z in FIG. 3 (A). It is an arrow view.
Although the first and second mixing promotion chambers 7 and 8 are used in a connected state, the display is complicated in FIGS. 3 (A), (B) and FIGS. 4 (A), (B). Therefore, it is described separately.
FIG. 3A shows the first mixing promotion chamber 7, which has a cylindrical casing 71 and a J-shaped cross section along the axis L1 of the casing 71. The J-shaped curved portion 721 is surrounded so as to be centered on the axis L1, the linear portion 722 is fixed to the casing 71, and the first guide member 72 extending in the entire region in the axis L1 direction of the casing 71 is linear. The cross-sectional shape is curved in the opposite direction to the J-shaped curved portion 721 at the back-to-back position with the portion 722, is fixed to the first guide member 72 and the casing 71, and extends across the entire axis L1 direction of the casing 71. The first guide member 73, the first upstream lid member 74 having a first exhaust gas introduction hole 76 (two-dot chain line) around the axis L 1, and the casing 71 Under exhaust system And a first downstream lid member 75 having a first exhaust gas discharge hole 77 in the vicinity of the center line L2 that is substantially parallel to the axis L1 and that passes through the center position of the curved portion of the second guide member 73. ing.
In the present embodiment, the curved portion R is provided in the flow direction of the exhaust gas at the end of the straight portion 722 of the first guide member 72 and the joint portion with the casing 71 so that the exhaust gas is easily bent in the flow direction. Thus, the flow resistance of exhaust gas is suppressed.
In addition, since the second guide member is fixed to the casing 71 and the first guide member 72, the mounting rigidity of the first and second guide members 72 and 73 to the casing 71 is improved, and the exhaust gas pulsates. The generated vibrations of the first and second guide members 72 and 73 are suppressed, and the durability of the first mixing promotion chamber 7 is improved and noise is prevented.

3 (A) and 3 (B) are complicated, the first upstream lid member (74), the first downstream lid member (75), and the second upstream lid member (81). The second downstream side cover member (82) is labeled because it is necessary for the description, but is not shown in the drawing.
Further, the exhaust gas introduction hole 76 and the exhaust gas discharge hole 77 are made substantially the same (or larger) as the diameter of the exhaust pipe connection portion 211 of the casing 21 to suppress an increase in exhaust gas circulation resistance.
Accordingly, the semicircular diameters of the curved portion 721 of the first guide member 72 and the curved portion of the second guide member 73 are slightly larger than the diameter of the exhaust pipe connecting portion 211.
The first mixing promotion chamber 7 has a first exhaust gas that is surrounded by the casing 71, the first guide member 72, the second guide member 73, the first upstream lid member 74, and the first downstream lid member 75. An exhaust gas flow passage 79 is formed.

FIG. 3B shows the second mixing promotion chamber 8, and the second mixing promotion chamber 8 has the shape and arrangement relationship of the casing 71, the first guide member 72, and the second guide member 73 in the first mixing promotion chamber 7. And in the same phase in the circumferential direction of the casing 71, the description thereof is omitted.
Accordingly, the second mixing promotion chamber 8 closes the casing 71, the first guide member 72, the second guide member 73, and the exhaust system path upstream side of the casing 71 and the center of the curved portion of the second guide member 73. The second upstream cover member 81 having the second exhaust gas introduction hole 83 in the vicinity of the position L2 and the exhaust system downstream side of the casing 71 are closed, and the second exhaust gas discharge hole 84 (two-dot chain line) is centered on the axis L1. ) Having a first downstream lid member 84.
When installed in the purification device casing 21 of the exhaust gas purification device 2, the first exhaust gas discharge hole 77 of the first downstream cover member 75 of the first mixing promotion chamber 7 and the second mixing promotion chamber 8 of the first mixing promotion chamber 8. (2) The second exhaust gas introduction hole 83 of the upstream cover member 81 is installed in a state in which the first mixing promotion chamber 7 and the second mixing promotion chamber 8 are in contact with each other with the circumferential phase of the casing 71 matched. To do.
Further, in the second mixing promotion chamber 8, the exhaust gas surrounded by the casing 71, the first guide member 72, the second guide member 73, the second upstream lid member 83, and the second downstream lid member 84 flows. An exhaust gas flow passage 85 is formed.

4A is an explanatory view of the flow path of exhaust gas in the first mixing promotion chamber, and FIG. 4B is an explanatory view of the flow path of exhaust gas in the second mixing promotion chamber.
4 (A) and 4 (B) are omitted because the drawing becomes complicated when the lead lines of the component codes are entered. For the components, see FIGS. 3 (A) and 3 (B).
In the first mixing promotion chamber 7 of FIG. 4A, exhaust gas from the direction of arrow F is introduced from the first exhaust gas introduction hole 76, and is formed by the curved portion 721 of the first guide member 72 and the casing 71. The exhaust gas flow passage 79 flows clockwise (on the drawing) along the circumferential direction of the casing 71, and is discharged from the first exhaust gas discharge hole 77 at the second guide member 73.
Since the second exhaust gas introduction hole 83 of the second mixing promotion chamber 8 is joined to the first exhaust gas discharge hole 77, the exhaust gas flows between the curved portion 721 of the first guide member 72 of the second mixing promotion chamber 8 and the casing. 71 flows in a counterclockwise direction (on the drawing) along the circumferential direction of the casing 71 and flows from the second exhaust gas discharge hole 84 toward the selective reduction catalyst 24 side.

In the first and second mixing promotion chambers 7 and 8, the exhaust gas is converted from the clockwise direction to the counterclockwise direction, thereby causing disturbance in the exhaust gas flow and mixing the urea water and the exhaust gas. To promote.
Further, since the exhaust gas flow passage 79 (85) has a structure in which the exhaust gas flows along the circumferential direction of the casing 71, the length N of the exhaust gas flow passage is N = 3 / 4πD with respect to the diameter D of the casing 71. . As for 3/4, as shown in FIG. 3 (A), the exhaust gas flow path was about 3/4 of the casing 71, and the coefficient was loaded because it ended.
Therefore, in the present embodiment, since the first and second mixing promotion chambers 7 and 8 are arranged in series, the length of the exhaust gas flow passage is 2N, which is sufficient for promoting the mixing of urea water and exhaust gas. The length of the exhaust gas flow passage can be ensured.

FIG. 5 shows the attachment position of the additive injection means, and the urea water injection nozzle 9 positions the first exhaust gas exhaust hole 77 of the first mixing promotion chamber 7 on the lower side in the gravitational direction. It is arranged on the upper side with the exhaust gas introduction hole 76 as the center.
This is because the urea water injection nozzle 9 is located on the upstream side of the first exhaust gas flow passage 79 of the first mixing promoting chamber 7 and above the first exhaust gas discharge hole 77 of the exhaust gas, with the first exhaust gas introduction hole 76 as the center. The mixing of additives cannot be promoted sufficiently, resulting in liquid particles, and even if it stays on the wall of the mixing promotion chamber and the lower side in the gravity direction, it is vaporized by the exhaust gas heat and flows downstream. In addition to being able to effectively use the additive, it has the effect of sufficiently increasing the mixing promotion distance N between CER and exhaust gas.

  The present invention can be applied to an exhaust gas purification device that renders pollutants contained in exhaust gas discharged from a diesel engine harmless by supplying an additive and using a catalyst device provided in an exhaust system.

1 engine (internal combustion engine)
2 Exhaust gas purification device 3 ECU
4 exhaust system path 5 intake path 6 third guide member 7 first mixing acceleration chamber 8 second mixing acceleration chamber 9 urea water injection nozzle (additive injection means)
21 Casing 22 Pre-stage oxidation catalyst 23 DPF
24 selective reduction catalyst 25 post-stage oxidation catalyst 72 first guide member 73 second guide member 76 first exhaust gas introduction hole 77 first exhaust gas discharge hole 79 first exhaust gas flow path (exhaust gas flow path)
83 Second exhaust gas introduction hole 84 Second exhaust gas discharge hole 85 Second exhaust gas flow passage (exhaust gas flow passage)
L1 axis L2 center line

Claims (5)

A catalyst device that is provided in an exhaust system passage of the internal combustion engine and purifies the exhaust gas of the internal combustion engine by supplying an additive;
Wherein provided upstream of the catalytic converter in the exhaust system path has an exhaust gas flow passage flowing along the flow of exhaust gas in the circumferential direction of the exhaust gas around the axis of the exhaust system path, the said flue gas A mixing promotion chamber for promoting mixing with the additive,
Provided in the exhaust gas introduction hole near the mixing promotion chamber, and additive injection means for injecting the additive into the exhaust gas flow passage,
Equipped with a,
The mixing promotion chamber is disposed in a state of being connected in series along the exhaust system path, and the first mixing promotion chamber is configured so that the circumferential flow of the exhaust gas in the exhaust gas flow path is reversed to each other; A second mixing promotion chamber,
The first mixing promotion chamber is disposed so that a cross section of the first mixing promotion chamber has a J shape, and the center of the curved portion of the J shape includes the axis, A front end is connected to the casing, extends along the axis, is disposed at a back-to-back position with the linear portion, and is sandwiched between the first guide member and the casing, and has a cross-section. The shape is curved in the direction opposite to the curved portion, the second guide member extending along the axis, and the exhaust system upstream side of the casing is closed, and the first guide disposed on the axis. The first upstream lid member having the exhaust gas introduction hole and the exhaust system downstream side of the casing are closed, and disposed on a center line parallel to the axis passing through the curved portion of the second guide member. 1st downstream which has the 1st exhaust gas discharge hole A first exhaust gas flow passage surrounded by the casing, the first guide member, the second guide member, the first upstream lid member, and the first downstream lid member. Forming,
In the second mixing promotion chamber, the first guide member and the second guide member are arranged in the same phase in the circumferential direction of the first mixing promotion chamber with respect to the casing, and close the exhaust gas system upstream side of the casing, A second upstream cover member having a second upstream cover member provided with a second exhaust gas introduction hole at a position opposed to the first exhaust gas discharge hole and a second exhaust gas discharge hole disposed on the axis. Forming a second exhaust gas flow passage surrounded by the casing, the first guide member, the second guide member, the second upstream lid member, and the second downstream lid member,
The exhaust gas purification apparatus for an internal combustion engine, wherein the first exhaust gas flow passage and the second exhaust gas flow passage are configured such that the flow of exhaust gas flowing through each of the first exhaust gas flow passage and the second exhaust gas flow passage is reversed in the circumferential direction . The casing is cylindrical;
The first guide member has a straight end fixed to the casing, and extends in the entire axial direction of the casing.
The second guide member, the exhaust gas purifying apparatus for an internal combustion engine according to claim 1, wherein the axially extending throughout the casing. The exhaust gas of an internal combustion engine according to claim 1 or 2 wherein the upstream side of the first exhaust gas introduction hole is characterized in that the third guide member configured bell mouth shape so as to introduce the exhaust gas is disposed Purification equipment. Cross-sectional areas of the first and second exhaust gas introduction holes, the first and second exhaust gas exhaust holes, and the first and second exhaust gas flow passages hold the first and second mixing promotion chambers. The exhaust gas purifying device for an internal combustion engine according to any one of claims 1 to 3, wherein the exhaust gas purifying device is substantially equal to or larger than a cross-sectional area of an exhaust pipe connection portion of the purifying device casing. The mounting position of the additive injection means for injecting the additive into the first exhaust gas flow passage is an upstream position of the first exhaust gas flow passage, and the first exhaust gas discharge hole of the first mixing promotion chamber is directed in the direction of gravity. by positioning the lower, the so disposed above the first center exhaust gas introduction hole, one of claims 1, characterized in that so as to inject the additives in the direction along the flow of the exhaust gas 3 An exhaust gas purification device for an internal combustion engine according to claim 1 .

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