JP6090632B2 - Exhaust purification equipment mixer - Google Patents

Description

  The present invention is arranged between a reducing agent supply device that injects a reducing agent into an exhaust passage and a catalytic converter that reacts the reducing agent with exhaust gas to purify the exhaust gas, and the reducing agent and exhaust gas are The present invention relates to an improvement of a mixer of an exhaust emission control device to be mixed.

  Such an exhaust emission control device for an engine is already known as disclosed in Patent Document 1.

JP 2011-111927 A

  The mixer of the exhaust gas purification device disclosed in Patent Document 1 is formed by attaching a plurality of swirl vanes to the inner peripheral surface of the outer ring, and has a large number of parts and requires press and welding for manufacturing. There are many manufacturing processes, and it is difficult to reduce the cost.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a mixer for the exhaust gas purification apparatus that has the minimum number of parts, is easy to manufacture, and is low in cost.

In order to achieve the above object, the present invention is provided between a reducing agent supply device that injects a reducing agent into an exhaust passage and a catalytic converter that purifies exhaust gas by reacting the reducing agent with exhaust gas. In the mixer of the exhaust gas purification apparatus for mixing the reducing agent and the exhaust gas, a rim made of a single plate press and attached to the exhaust passage, and a non-porous hub disposed at the center of the rim, A plurality of blades interposed between the rim and the hub, each blade being integrated with the first blade half and the first blade half and the rim integrally connecting the rim and the hub. And a second blade half separated from the hub to form a first slit therebetween and also separated from a first blade half of an adjacent blade to form a second slit therebetween. Constituted by a, the second blade halves, by axially offset through the stepped portion relative to the first blade halves, and shall have a plane orthogonal to the axial direction The first and second slits are extended in the axial direction. The catalytic converter corresponds to a secondary catalytic converter 3 in an embodiment of the present invention described later.

According to the features of the present invention, a mixer composed of a rim, a hub and a plurality of blades can be obtained only by pressing a single plate material, has a minimum number of parts, is easy to manufacture, and is inexpensive. Can be provided. In addition, the mixer includes a rim, a non-porous hub disposed at the center of the rim, and a plurality of blades interposed between the rim and the hub, and each blade is integrally connected between the rim and the hub. The first blade half and the first blade half and the rim are integrally connected to each other, separated from the hub to form a first slit therebetween, and separated from the first blade half of the adjacent blade. And a second blade half that forms a second slit between the second blade half and the second blade half by offsetting the second blade half in the axial direction with respect to the first blade half via the stepped portion. Since the first and second slits are expanded in the axial direction, the reducing agent injected from the reducing agent supply device collides with the first and second blade halves, diffuses and atomizes, and mixes well with the surrounding exhaust gas. Exhaust gas and It is possible to create a good mixture of Motozai. A part of the air-fuel mixture smoothly passes through the first slit opened in the axial direction between the adjacent second blade half and the hub, and the remaining part of the air-fuel mixture is the second blade of one adjacent blade. The second slit opened in the axial direction between the half portion and the first blade half portion of the other blade can smoothly pass toward the catalytic converter.

The top view which cut through the principal part of the exhaust gas purification apparatus for diesel engines which concerns on this invention. FIG. 2 is an enlarged sectional view taken along line 2-2 in FIG. 1. FIG. 3 is a developed sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a developed sectional view taken along line 4-4 of FIG. The perspective view of a mixer.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, in FIG. 1, a primary catalytic converter 2 and a secondary catalytic converter 3 are disposed in the exhaust passage 1 of the diesel engine E from the upstream side. The primary catalytic converter 2 oxidizes and removes CO and HC in the passing exhaust gas, and the secondary catalytic converter 3 reduces and removes NOx in the passing exhaust gas.

  Further, a reducing agent supply device 5 and a mixer 6 are disposed in the exhaust passage 1 between the primary and secondary catalytic converters 2 and 3 from the upstream side. The reducing agent supply device 5 injects a reducing agent r such as urea water toward the mixer 6. The mixer 6 injects the reducing agent r injected from the reducing agent supply device 5 and the exhaust gas g passing through the exhaust passage 1. Are mixed and sent to each part of the secondary catalytic converter 3 evenly.

  The secondary catalytic converter 3 is made of ceramics having a honeycomb structure, and is supported by a holding cylinder 8 connected to the upstream side and the downstream side of the exhaust passage 1 via a mat 9.

  As shown in FIGS. 1 to 4, the mixer 6 is formed by pressing a single stainless steel plate, and has a rim 10 having an L-shaped cross section and a non-hole arranged at the center of the rim 10. The hub 11 includes a plurality of (four in the illustrated example) blades 13 interposed between the rim 10 and the hub 11. Each blade 13 includes a first blade half 13 a that integrally connects the rim 10 and the hub 11, and a second blade half 13 b that is integrally connected to the first blade half 13 a and the rim 10. The second blade half 13b is separated from the hub 11 to form a first slit 12a therebetween, and is separated from the first blade half 13a of the adjacent blade 13 and the second blade half 13b therebetween. Two slits 12b are formed. The first and second slits 12a and 12b are connected to each other to form an L shape.

  Further, the second blade half 13b is offset e with respect to the first blade half 13a via the stepped portion 13c to the exhaust downstream side, whereby the first and second slits 12a and 12b are arranged in the axial direction. Has been spread.

  Next, the operation of this embodiment will be described.

  The exhaust gas g of the engine E from which CO and HC have been oxidized and removed in the primary catalytic converter 2 exits the primary catalytic converter 2 and moves to the mixer 6 together with the reducing agent r injected from the reducing agent supply device 5.

  The mixer 6 includes a rim 10, a non-holed hub 11 disposed at the center of the rim 10, and a plurality of blades interposed between the rim 10 and the hub 11. The first blade half 13a integrally connecting the hub 11 and the first blade half 13a and the rim 10 are integrally connected, and the first blade 12 is separated from the hub 11 to form a first slit 12a therebetween. The second blade half 13b is separated from the first blade half 13a of the adjacent blade 13 and the second blade half 13b is formed between the first blade half 13a and the second slit 12b connected to the first slit 12a. The first and second slits 12a and 12b are widened in the axial direction by offsetting the portion 13b in the axial direction with respect to the first blade half 13a via the stepped portion 13c. Therefore, the reducing agent r injected from the reducing agent supply device 5 collides with the first and second blade halves 13a and 13b, diffuses and atomizes, and mixes well with the surrounding exhaust gas g. A good mixture of the reducing agent r can be produced. A part of the air-fuel mixture smoothly passes through the first slit 12a opened in the axial direction between the adjacent second blade half part 13b and the hub 11 and travels toward the secondary catalytic converter 3, and the above-mentioned mixing is performed. The remaining portion of the air smoothly passes through the second slit 12b opened in the axial direction between the second blade half 13b of the adjacent one blade 13 and the first blade half 13a of the other blade 13. It heads for the secondary catalytic converter 3. In this way, the air-fuel mixture can be evenly sent to each part of the secondary catalytic converter 3. Therefore, in the secondary catalytic converter 3, NOx in the exhaust gas g can be reacted with the reducing agent r to reduce and remove, and the detoxified exhaust gas g is released into the atmosphere.

  By the way, the mixer 6 composed of the rim 10, the hub 11 and the plurality of blades 13 can be obtained only by pressing a single plate material, has a minimum number of parts, is easy to manufacture, and is provided at low cost. be able to.

  The present invention is not limited to the above-described embodiment, and various design changes can be made without departing from the gist thereof. For example, the first and second slits 12a and 12b can be expanded in the axial direction by offsetting the second blade half 13b to the upstream side of the exhaust via the step 13c with respect to the first blade half 13a. . Further, the open end of the rim 10 can be bent toward the exhaust upstream side, and the rim 10 can be fitted and welded to the inner peripheral surface of the upstream end of the holding cylinder 8. When the exhaust pipe on the side is fitted, the rim 10, the holding cylinder 8 and the exhaust pipe can be welded by one welding. The rim 10 can also be attached to the upstream exhaust pipe by welding.

e ··· Offset g ··· Exhaust gas r ··· Reducing agent 1 ··· Exhaust passage 3 ···· Catalytic converter (secondary catalytic converter)
5... Reducing agent supply device 6... Mixer 10 .. Rim 11... Hub 12 a... First slit 12 b. ... Blade 13a ... First blade half 13b ... Second blade half 13c ... Step

Claims (1)

A reducing agent supply device (5) for injecting the reducing agent (r) into the exhaust passage (1), and a catalytic converter (3) for purifying the exhaust gas (g) by reacting the reducing agent (r) with the exhaust gas (g). In the mixer of the exhaust gas purification apparatus, which is disposed between the reducing agent (r) and the exhaust gas (g).
A rim (10) made of a single plate press, attached to the exhaust passage (1), a non-porous hub (11) disposed at the center of the rim (10), and these rims (10) And a plurality of blades (13) interposed between the hubs (11), and each blade (13) is connected to the rim (10) and the hub (11) integrally with a first blade half (13a). ) And the first blade half (13a) and the rim (10), and is separated from the hub (11 ) to form a first slit (12a) between them and adjacent thereto A second blade half (13b) that is separated from the first blade half (13a) of the blade (13) and forms a second slit (12b) therebetween, and the second blade half ( 13b) the first blade By via stepped portion (13c) offset (e) in the axial direction, and shall have a plane orthogonal to the axial direction relative to the part (13a), said first and second slits ( 12a, 12b) is an axially widened mixer for an exhaust gas purification apparatus.

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