KR20090095182A - Particulate Filter - Google Patents

Abstract

A particulate matter collecting filter structure is provided to minimize pressure drop by discharging exhaust gas smoothly, and to produce the filter structure as a ceramic sintering body. A particulate matter collecting filter structure includes a housing(100), a first filter and a second filter. The first filter and the second filter includes a plurality of cell walls(170) and a through-passage(160). The cell wall is formed with a plurality of plates lain at right angles. A plurality of inner spaces are formed between the cell walls. The inner wall includes a first exhaust passage(140), a second passage(150), and a penetration passage. The penetration passage is comprised of a first penetration passage(161) and a second penetration passage(162). A mixing part(130) is formed by mixing exhaust gas passing through the first filter.

Description

Filter structure for collecting particulate matter {Particulate Filter}

The present invention relates to a filter structure for collecting particulate matter, and more particularly to a filter structure for collecting particulate matter, which is made of a ceramic sintered body and minimizes the pressure drop by smoothly discharging exhaust gas.

Diesel engines have the advantage of reducing fuel consumption by using unrefined lower fuel, but have a disadvantage in that a large amount of nitrogen oxides (NOx) and particulate matter (PM) are emitted.

Particularly, the particulate matter (PM) is a generic term for particulate matters contained in exhaust gas of diesel engines such as carbon-containing fine particles, sulfur-containing fine particles such as sulfate and high molecular weight hydrocarbon particles.

Particulate matter (PM) contains harmful substances that cause allergies or cancer, and an exhaust gas purification device has been developed to remove them.

As exhaust gas purifiers for diesel engines developed to date, trap type exhaust gas purifiers and open exhaust gas purifiers are largely known.

Among these, a trap type | mold exhaust gas purification apparatus is a closing type honeycomb filter (also called diesel PM filter or DPF).

The conventional filter has a plurality of cells extending along the exhaust direction, and when the exhaust gas passes through the filter, particulate matter is trapped by the cell walls, thereby removing the particulate matter from the exhaust gas.

The following describes in detail the structure of the exhaust gas purifying apparatus 1 and the conventional filter proposed in the Patent Publication No. 10-2005-0105603.

1 is a schematic diagram of a conventional exhaust gas purifying apparatus for a diesel engine.

As shown in Fig. 1, the exhaust gas purification device 1 is an apparatus for purifying exhaust gas discharged from the diesel engine 2 as an internal combustion engine.

The diesel engine 2 is provided with many cylinders, and each cylinder is connected with the branch part 4 of the manifold 3 which consists of metal materials.

Each branch 4 is connected to one manifold main body 5, respectively, and exhaust gas discharged from each cylinder is concentrated in one place.

On the downstream side of the exhaust manifold 3, a first exhaust pipe 6 and a second exhaust pipe 7 made of a metal material are arranged. The upstream end of the first exhaust pipe 6 is connected to the manifold body 5.

Between the first exhaust pipe 6 and the second exhaust pipe 7, a cylindrical casing 8 made of a metal material is arranged.

The upstream end of the casing 8 is connected with the downstream pipe of the first exhaust pipe 6, and the downstream end of the casing 8 communicates with the upstream end of the first exhaust pipe 7.

Therefore, the casing 8 is arrange | positioned at the intermediate part of the exhaust pipe 6,7.

The first exhaust pipe 6, the casing 8 and the second exhaust pipe 7 communicate with each other, and exhaust gas flows therein.

 The central portion of the casing 8 has a larger diameter than the exhaust pipes 6, 7. Therefore, the inner region of the casing 8 is wider than the inner regions of the exhaust pipes 6, 7, and the filter 9 is accommodated in the casing 8.

The heat insulating material 10 is normally inserted between the outer peripheral surface of the filter 9 and the inner peripheral surface of the casing 8.

The heat insulating material 10 is a mat-shaped object including a ceramic fiber, and is a member for minimizing energy loss during regeneration by preventing heat from being emitted from the outermost circumference of the filter 9.

The filter 9 is mainly formed of a porous silicon carbide sintered body which is a kind of ceramic sintered body.

2 is an enlarged cross-sectional view of a filter mounted in a conventional exhaust gas purifying apparatus for a diesel engine.

As shown in FIG. 2, the filter 9 has a plurality of through cells 12 having a substantially square cross section regularly formed along the discharge direction of the exhaust gas, and each through cell 12 has a thin cell wall ( 13) are separated from each other.

On the outer surface of the cell wall 13, an oxidation catalyst made of platinum group element, other metal element, oxide thereof, or the like is supported.

Moreover, the opening part of each through cell 12 is sealed by the sealing material 14 in the one end surface 9a, 9b side.

Therefore, the whole cross section of the conventional filter shows a checkerboard shape.

The density of the cell is set within 100-200 pieces / inch, and the thickness of the cell wall is set within 0.3-0.6 mm. Of the plurality of cells, about half are opened in the inlet end face 9a, and the remaining cells are opened in the outlet end face 9b.

Figure 3 shows the exhaust gas circulation path of the filter mounted on the conventional exhaust gas purification device for diesel engines.

As shown in FIG. 3, the introduced exhaust gas passes through the cell wall and particulate matter is collected on the porous cell wall surface, and the purified gas enters the neighboring cell where the outlet side is open and is discharged to the rear end of the filter.

However, the conventional filter has a high collection efficiency because all the exhaust gas must pass through the wall of the cell when the exhaust gas passes through the filter, but the exhaust pressure is high due to the high pressure loss.

In addition, if the cell wall is simply removed to reduce the pressure loss, the exhaust pressure is lowered, the pressure loss is reduced, but the collection rate of particulate matter is also lowered.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a particulate matter collecting filter structure for reducing exhaust pressure while maintaining a collecting rate of particulate matter above a certain ratio.

In order to achieve the above object, the particulate matter trapping filter structure of the present invention, the front and rear housing that the exhaust gas flows; First and second filters respectively inserted in the exhaust gas flow direction in the housing; The first filter and the second filter, including, a plurality of cell walls made of porous; A through passage surrounded by the cell wall and open to all sides of the exhaust gas flow direction; Comprising a, and the mixing portion is formed between the first filter and the second filter and the exhaust gas passing through the first filter is mixed again to move to the second filter.

The mixing unit includes a space formed inside the housing as the first filter and the second filter are spaced apart from each other.

The through passage includes a first through passage formed in the first filter; A second through passage formed in the second filter; The first through passage and the second through passage are alternately arranged in the flow direction of the exhaust gas.

The first filter and the second filter, the first exhaust path is surrounded by the cell wall, the front of the exhaust gas flow direction is open, the rear is closed; It further comprises, wherein each of the cell walls surrounding the through passage is in contact with the first exhaust passage.

The first filter and the second filter, the second exhaust path is surrounded by the cell wall, the front of the exhaust gas flow direction is sealed, the rear is open; It further comprises, wherein each cell wall surrounding the second exhaust passage is in contact with the first exhaust passage.

The first exhaust passage, the second exhaust passage and the through passage is composed of a plurality, the first exhaust passage is more than or equal to the sum of the second exhaust passage and the through passage, the through passage the second More than or equal to the exhaust path

According to the filter structure for collecting particulate matter of the present invention as described above has the following effects.

A mixing portion is formed between the first filter and the second filter, so that the purified exhaust gas and the unpurified exhaust gas from the first filter are evenly mixed.

Since the mixing portion is formed of a space formed inside the housing, there is an effect of simplifying the overall structure.

By arranging the first through passage and the second through passage alternately in the flow direction of the exhaust gas, it is possible to reduce the inflow of the exhaust gas passing through the first through passage immediately into the second through passage.

By contacting each of the cell walls surrounding the through passage with the first exhaust passage, exhaust gas flows through the cell wall of the first exhaust passage to the through passage during exhaust gas flow.

By contacting each of the cell walls surrounding the second exhaust passage with the first exhaust passage, the exhaust gas flows through the cell wall of the first exhaust passage to the second exhaust passage during exhaust gas flow.

By making the first exhaust passage more than or equal to the sum of the second exhaust passage and the through passage, and making the through passage more than or equal to the second exhaust passage, there is an effect of reducing the exhaust pressure of the exhaust gas.

4 is a perspective view of a particulate matter collecting filter structure according to an embodiment of the present invention, Figure 5 is a cross-sectional view of the particulate matter collecting filter structure according to an embodiment of the present invention as seen from AA of Figure 4, Figure 6 4 is a cross-sectional view of a first filter according to an embodiment of the present invention as viewed from BB of FIG. 4, and FIG. 7 is a cross-sectional view of a second filter according to an embodiment of the present invention as viewed from CC of FIG. It is sectional drawing of the filter structure for particulate matter collection which concerns on the Example of this invention.

4 to 8, the particulate matter collecting filter structure of the present invention includes a housing 100, a first filter 110, a second filter 120, and a mixing unit 130.

The housing 100 has a cylindrical shape and is mainly mounted on a casing of the exhaust gas purification device, and may be integrally formed with the casing in some cases.

The housing 100 is open all the front and rear of the exhaust gas flow direction so that the exhaust gas flows therein, and the first filter 110 and the second filter in the exhaust gas flow direction inside the housing 100. Each filter 120 is inserted.

The first filter 110 and the second filter 120 is formed in a cylindrical shape similar to the housing 100, the inner circumferential surface of the housing 100, the first filter 110 and the second filter 120. It is press-fitted so that the outer circumferential surface of the

In addition, the first filter 110 is disposed in front of the exhaust gas flow direction, that is, the inlet side of the exhaust gas, and the second filter 120 is disposed behind the exhaust gas flow direction, that is, the outlet side of the exhaust gas. .

Therefore, the first filter 110 is disposed concentrically with the second filter 120.

In addition, the first filter 110 and the second filter 120 are mounted at a predetermined interval, wherein the first filter 110 between the first filter 110 and the second filter 120 is provided. The exhaust gas passed through is mixed again to form a mixing unit 130 for moving to the second filter 120.

The mixing unit 130 is formed of an empty space formed inside the housing 100, one end communicates with the first filter 110, and the other end communicates with the second filter 120.

Due to the above structure, the particulate matter of the exhaust gas not filtered by the first filter 110 is filtered again by the second filter 120.

The first filter 110 and the second filter 120 are made of a porous cell wall 170, and the cell wall 170 is long to be parallel to the exhaust gas flow direction.

In addition, the cell wall 170 has a rectangular shape in which a plurality of planks are formed at regular intervals orthogonal to each other, and thus a plurality of internal spaces of a hexahedron are formed between the cell walls 170.

In this case, a first exhaust passage 140, a second exhaust passage 150, and a through passage 160 are formed in the internal space.

The through passage 160 is open in front and rear of the exhaust gas flow direction, and all four surfaces thereof are surrounded by the cell wall 170.

In detail, the through passage 160 includes a first through passage 161 formed in the first filter 110 and a second through passage 162 formed in the second filter 120.

Like the first filter 110 and the second filter 120, the first through passage 161 and the second through passage 162 have the housing 100 interposed therebetween. Are arranged in front and rear of, but not in a straight line.

That is, the first through passage 161 and the second through passage 162 are alternately arranged in the exhaust gas flow direction.

Therefore, as shown in FIG. 8, when viewed in the exhaust gas flow direction from the first filter 110, the second through passage 162 is not visible.

As such, the first through passage 161 and the second through passage 162 are alternately arranged in the exhaust gas flow direction so that the exhaust gas passing through the first through passage 161 is mixed with the mixing unit 130. ) To mix evenly.

On the other hand, the first exhaust passage 140 is open in the exhaust gas flow direction and the rear is closed, the second exhaust passage 150 is closed in the front of the exhaust gas flow direction and the rear is open.

The first exhaust passage 140 and the second exhaust passage 150 are formed in both the first filter 110 and the second filter 120 similarly to the through passage 160. The second exhaust path 150 may not be included.

That is, the first filter 110 and the second filter 120 may be composed of only the through passage 160 and the first exhaust passage 140 according to the collection efficiency of particulate matter.

In addition, the first exhaust passage 140 is disposed to be in contact with each cell wall 170 surrounding the through passage 160 and each of the cell walls 170 surrounding the second exhaust passage 150, respectively.

That is, each of the cell walls 170 surrounding the through passage 160 and each of the cell walls 170 surrounding the second exhaust passage 150 are in contact with the first exhaust passage 140.

Accordingly, the first exhaust passage 140 is adjacent to the through passage 160 and the second exhaust passage 150, but the through passage 160 does not come into contact with the second exhaust passage 150. .

In the first exhaust path 140 in which the outlet port is closed by the above configuration, the exhaust gas entering the first exhaust path 140 passes through the cell wall 170 when the exhaust gas flows, so that the second exhaust path 150 or To be moved to the through passage 160.

An arrangement structure of the through passage 160, the first exhaust passage 140, and the second exhaust passage 150 configured as described above is as follows.

As illustrated in FIGS. 6 and 7, the through passage 160, the first exhaust passage 140, and the second exhaust passage 150 are arranged in one row and the other in the flow direction of the exhaust gas, respectively. Each row arranged side by side is arranged in a vertical stack.

In other words, when viewed from the exhaust gas flow direction, the through passage 160, the first exhaust passage 140, and the second exhaust passage 150 are arranged in a diagonal direction along the edges, respectively, and the first exhaust passage 140. ), The second exhaust passage 150, the through passage 160, and the first exhaust passage 140 are sequentially stacked.

However, the second exhaust path 150 of the first filter 110 may be disposed such that the positions of the first through path 161 and the second through path 162 of the through path 160 are alternate with each other. ) And the position of the second exhaust passage 150 of the second filter 120 are also alternately arranged.

In other words, the second exhaust passage 150 of the first filter 110 is disposed in line with the second through passage 162 of the second filter 120, and the first of the first filter 110. The through passage 161 is in line with the second exhaust passage 150 of the second filter 120.

By the above arrangement structure, the ratio of the first exhaust passage 140, the second exhaust passage 150, and the through passage 160 is configured in the order of the first exhaust passage ≥ the passage passage ≥ the second exhaust passage.

That is, the first exhaust passage 140 is greater than or equal to the sum of the second exhaust passage 150 and the through passage 160, and the through passage 160 is greater than or equal to the second exhaust passage 150. same.

By making the through passage 160 more than or equal to the second exhaust passage 150 as described above, the amount of exhaust gas that does not pass through the cell wall 170 is increased to reduce the exhaust pressure.

The following describes the exhaust gas filtering process according to the embodiment of the present invention having the above configuration.

As shown in FIG. 5, the exhaust gas entering from the left side, that is, the exhaust gas inlet side moves to the first filter 110 mounted on the inlet side, and the first filter 110 of the first filter 110 having the inlet side open. It moves to the first exhaust 140 and to the first through passage 161.

At this time, the second exhaust path 150 of the first filter 110 is inlet side is closed, the exhaust gas does not flow.

The exhaust gas entered into the first through passage 161 is moved to the mixing unit 130 in a state in which particulate matter is not filtered, and the exhaust gas entering the first exhaust passage 140 is immediately closed because the outlet port is sealed. It does not move to the mixing unit 130 but passes through the cell wall 170 and moves to the adjacent second exhaust path 150 and the first through path 161.

At this time, the cell wall 170 collects and filters particulate matter contained in the exhaust gas when the exhaust gas passes.

Therefore, the exhaust gas moved from the first exhaust passage 140 to the second exhaust passage 150 and the first through passage 161 is in a purified state.

The purified exhaust gas is moved to the mixing unit 130 through the second exhaust passage 150 and the first through passage 161.

As described above, the exhaust pressure of the exhaust gas may be lowered due to the first through passage 161, but the particulate matter collection efficiency may be lowered due to the unpurified exhaust gas escaping from the first through passage 161.

Therefore, in order to increase the collection efficiency of the particulate matter, the mixing unit 130, the unpurified exhaust gas entering through the first through passage 161, the second exhaust passage 150 and the first through passage 161. Mix the purified exhaust gas from the mixture evenly.

The evenly mixed exhaust gas flows back into the second filter 120.

In this case, since the first through passage 161 is disposed to be alternate with the second through passage 162, the unpurified exhaust gas introduced through the first through passage 161 is directly connected to the second through passage 162. To reduce the flow into the

The exhaust gas introduced into the second filter 120 is moved to the first exhaust passage 140 and the second through passage 162 where the inlet is opened.

Exhaust gas entering the second through passage 162 exits the outlet of the housing 100 without filtering, and the exhaust gas entering the first exhaust passage 140 passes through the cell wall 170 and is neighbored. After moving to the second exhaust passage 150 and the second through passage 162, it exits to the outlet of the housing 100.

At this time, the exhaust gas flowing out of the second through passage 162 may be mixed in the mixing unit 130 to reduce the particulate matter, thereby increasing the collection efficiency of the particulate matter.

As described above, the exhaust gas purified from the first filter 110 and the unpurified exhaust gas are uniformly mixed through the mixing unit 130 and refiltered through the second filter 120, so that the exhaust gas exhaust pressure is reduced. It will be able to reduce and maintain the collection efficiency of particulate matter over a certain ratio.

The filter structure for collecting particulate matter according to the present invention is not limited to the above-described embodiments, and may be variously modified and implemented within the range in which the technical idea of the present invention is permitted.

1 is a schematic diagram of an exhaust gas purification apparatus of a conventional diesel engine,

2 is an enlarged cross-sectional view of a filter structure mounted on a conventional exhaust gas purification device for a diesel engine,

3 is a schematic diagram showing an exhaust gas circulation path of a filter installed in a conventional exhaust gas purification device for a diesel engine,

4 is a perspective view of a particulate matter collecting filter according to an embodiment of the present invention,

5 is a cross-sectional view of a particulate matter collecting filter according to an embodiment of the present invention as seen from A-A of FIG.

6 is a cross-sectional view of a first filter according to an embodiment of the present invention as seen from B-B of FIG. 4,

7 is a cross-sectional view of a second filter according to an embodiment of the present invention as seen from C-C of FIG.

FIG. 8 is a cross-sectional view of the particulate matter collecting filter structure according to the embodiment of the present invention as seen from B-B of FIG. 4.

<Description of the symbols for the main parts of the drawings>

100 housing, 110 first filter,

120: second filter, 130: mixing section,

140: first exhaust passage, 150: second exhaust passage,

160: through passage, 170: cell wall,

Claims (6)

A housing in which the front and rear sides are opened to allow the exhaust gas to flow; First and second filters respectively inserted in the exhaust gas flow direction in the housing; Including but not limited to, The first filter and the second filter, A plurality of cell walls made of porous material; A through passage surrounded by the cell wall and open to all sides of the exhaust gas flow direction; Including, A filter structure for collecting particulate matter, characterized in that a mixing portion is formed between the first filter and the second filter and the exhaust gas passing through the first filter is mixed again to move to the second filter. The method of claim 1, The mixing unit, And a space formed inside the housing as the first filter and the second filter are spaced apart from each other. The method according to claim 1 or 2, The through passage, A first through passage formed in the first filter; A second through passage formed in the second filter; Consisting of, And the first through passage and the second through passage are alternately disposed in the flow direction of the exhaust gas. The method according to claim 1 or 2, The first filter and the second filter, A first exhaust path surrounded by the cell wall, the front of which is open in the exhaust gas flow direction and whose rear is closed; It is made, including more And each cell wall surrounding the through passage is in contact with the first exhaust passage. The method of claim 4, wherein The first filter and the second filter, A second exhaust path surrounded by the cell walls, the front of the exhaust gas flow direction being closed and the rear of the cell being open; It is made, including more And each cell wall surrounding the second exhaust passage is in contact with the first exhaust passage. The method of claim 5, wherein The first exhaust passage, the second exhaust passage and the through passage is composed of a plurality, The first exhaust passage is greater than or equal to the sum of the second exhaust passage and the through passage, The filter for collecting particulate matter, characterized in that the through passage more than or equal to the second exhaust passage.

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