JP2002303124A - Particulate matter removing device for exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variation of exhaust pressure (pressure loss of a filter), and to continuously backwash and regenerate the filter in an operation, in a filter that filters and collects a particulate matter of an exhaust gas, and burns out and regerates this. SOLUTION: A section member fixed to a body and a filter having a rotating wall flow honeycomb structure are assembled, thereby constituting one filter section with a small scale (1/6 to 1/30 of the entire filter) independent of a flow passage of the exhaust gas. The filter section performs the regenerating process such as the backwashing or burning. This is repeated subsequently and continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing particulate matter from exhaust gas discharged from a vehicle equipped with a diesel engine. Specifically, particulate matter (PM) consisting of carbon fine particles in exhaust gas emitted from diesel vehicles,
The filter is divided into a plurality of filter sections, or collected in the filter section in a divided mode, and the particulate matter collected and accumulated in the filter sections is back-washed with air or the like flowing in the reverse direction from the exhaust gas downstream side. A particulate regeneration device (DPF) for exhaust gas such as a continuous regeneration type diesel engine that regenerates a filter by peeling it off from the filter
About.

[0002]

2. Description of the Related Art Conventionally, pollution caused by a large amount of particulate matter, that is, carbon fine particles emitted from so-called diesel vehicles such as trucks and buses has been regarded as a problem, and countermeasures have been taken. As a typical particulate matter removing device, a large number of alternately plugged through holes are arranged in the longitudinal direction, and a partition wall of the through holes is a honeycomb structure serving as a filter. There are wall flow honeycombs that make up the road. Since the wall flow honeycomb is configured such that the filter of the partition wall is always clogged with particulate matter, the wall flow honeycomb is usually configured to filter and collect with a pair of E and F filters as shown in FIG. ing. That is, the particulate matter of the exhaust gas is first filtered and collected by the filter E. Then, when the particulate matter adheres and accumulates on the filter E and is clogged, the pressure sensor detects that the ventilation resistance increases, and the switching valve G
The filter is switched to the filter F to filter and collect. The filter E is then regenerated by backwashing and / or incinerating particulate matter that has clogged and accumulated in the filter. Similarly, the filter F is switched and regenerated when particulate matter is clogged in the filter, and this is repeated alternately. H in the figure
Is an exhaust pipe for introducing exhaust gas.

[0003] The exhaust gas particulate matter removing apparatus includes:
The filter is provided with a switching type regeneration function filter of F2 units, so when the switching valve G fails or the pressure sensor or the controller fails, excessive clogging of the filter occurs, Exhaust pressure (pressure loss) becomes abnormally high due to ventilation resistance. Further, when the amount of the deposited particulate matter increases, the combustion temperature becomes excessively high due to the heat generated when the particulate matter burns (combustion heat), and there is a problem that the temperature locally rises and the filter is melted and broken.

Further, in the regeneration by incineration of the filter, there are means for directly heating the filter, for heating the exhaust gas, and for heating the accumulated particulate matter with high-temperature air. Large amounts of energy are required to burn materials.

As a decisive factor, Japanese Patent Application Laid-Open No. H11-294
As disclosed in US Pat. No. 140, if the system is abnormal and particulate matter is excessively collected and deposited on the filter, the exhaust gas is avoided in order to avoid problems such as heat damage during regeneration of the filter. Need to flow part of the air into the atmosphere. That is, if this is continued, there is a problem that the exhaust gas particulate matter is dripped off.

Japanese Patent Application Laid-Open No. 12-42327 proposes a simple and efficient regenerating apparatus using a wall flow honeycomb made of porous silicon carbide. However, these apparatuses have a problem that exhaust gas flows only downstream in a certain direction. Even if the deposited particulate matter is incinerated, the residue, that is, ash, etc., accumulates in the filter, and there is a problem that the porous partition walls continue to reduce the function as the filter.

[0007] In a specific example of a conventional wall flow honeycomb, ash generated after incineration of particulate matter accumulates on the surface of the filter and the structure of the partition walls. Cracks have occurred in the honeycomb. In addition, there is a problem that the time of the collecting operation is shortened by 50% or more compared to the initial period due to accumulation of residues and ash after incineration. Japanese Patent Application Laid-Open No. H11-280451 improved this by disposing a ceramic fiber structure and a conductive fired body downstream thereof in a filter device.
There is a problem that the time of the collecting operation is reduced to 75% of the initial time in the test operation of collecting and regenerating 0 times. That is, there is a problem that the processing function (processing capacity) is steadily reduced, so that not only the reproduction cycle must be shortened but also the life is shortened.

[0008] In view of the above, there has been proposed a particulate matter removing device for regenerating the filter by backwashing the switching type filter device with a regenerating function with air or the like blown in the direction opposite to the exhaust gas from the downstream side of the exhaust gas. . JP-A-1-159408
No. 2 proposes that the honeycomb structure is divided into two parts and backwashed alternately by half. However, this is because the filter is housed in a single container and the timing of the backwash is not limited to the condition. Is extremely difficult to set. In recent years, in order to solve this, two sets of filter devices each containing one filter are usually set, and one filter in the whole is processed. However, similarly to the above, the switching timing and the setting of the amount of backwash air are costly. That is, Japanese Patent Application Laid-Open No.
In (2), either the temperature of the dust-containing gas or the temperature of the filter is detected, and the amount of backwash air is set from this. In Japanese Patent Application Laid-Open No. 9-264121, the timing of backwash is estimated from the pressure loss and the soot accumulation amount per filter.

[0009]

The above-mentioned conventional particulate matter removing device for diesel engine exhaust uses a wall flow honeycomb as a filter for filtering and collecting particulate matter, and the filter is deposited on the filter and clogged. This is a process in which the particulate matter is incinerated or / backwashed and peeled, and then incinerated / or burned and then backwashed and peeled to perform a process such as regeneration. That is, the filter is usually a set of two units of E and F, and the filter is switched during use of E, and the particulate matter of the filter of F deposited and clogged is incinerated and regenerated by fresh air heated by an electric heater. It is supposed to.

[0010] The above-mentioned conventional device not only requires two filter devices of E and F, but also requires members such as a switching valve, a branching device, various sensors and the like, and of course, the filter is updated every time switching is performed. Therefore, there is a problem that a difference in performance from before the switching is increased. That is, there has conventionally been a demand for a diesel engine exhaust particulate matter removal apparatus that can be continuously regenerated without performing the above switching.

SUMMARY OF THE INVENTION An object of the present invention is to develop an apparatus for removing particulate matter from exhaust gas, which does not require switching between filters, in view of the above-mentioned problems of the conventional filters. That is, the particulate matter of the diesel engine exhaust gas is filtered and collected by one filter and deposited on the filter, which is incinerated with an electric heater or a high-temperature combustion gas, thereby removing the ash deposited on the filter. It is another object of the present invention to provide an exhaust gas particulate matter removing apparatus that can be continuously regenerated during operation.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to provide a filter for filtering and collecting particulate matter of exhaust gas by a filter, removing the particulate matter by heating, incineration, and regenerating the filter. By dividing the filter sections into separate sections, or by configuring in a divided manner, the divided filter sections are made independent, and the solution is solved by backwashing the filters in the filter sections to regenerate and / or incinerate backwash. Is done. That is, the filter section is cut off from the flow path of the exhaust gas, so that the filter section is independent and can be regenerated by backwashing and / or incineration with a single filter.

The entire filter is continuously regenerated by repeating the regeneration by backwashing and / or incineration of the filter section in order.

[0014]

In order to achieve the above objects, the present invention relates to an apparatus for removing particulate matter from exhaust gas, which comprises a plurality of divided or small-sized filter sections each having the same mode as the divided sections. By constituting in an embodiment, the particulate matter deposited in each small-scale filter section is incinerated with heated air, and then backwashed with air or backwashed and then incinerated with heated air. Is made.

The material of the filter according to the present invention is not limited to a porous ceramic honeycomb as long as it can filter and collect particulate matter of a diesel engine exhaust gas. Is available.

The movement and rotation of the section member constituting the filter section or the movement of the filter such as a wall flow honeycomb can be mechanically driven by a deceleration motor, a rotating cam, a ratchet, a solenoid or the like.

[00017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments, a particulate matter removal device for exhaust gas of a diesel vehicle equipped with a diesel engine has been described. However, the present invention is not limited to this. Land engines and marine engines using large and small diesel engines Needless to say, it can be used for the treatment of exhaust gas containing dust, cogeneration and other particulate matter (dust exhaust gas). Hereinafter, the present invention will be described in detail with reference to examples. However, the same members and the same applications are denoted by the same reference numerals and description thereof will be omitted.

[0018]

Embodiment 1 FIG. 1 is a partially cutaway perspective view showing an embodiment of an exhaust gas particulate matter removing apparatus according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. . The filter 2 of the exhaust gas particulate matter removing device 1 is made of a porous silicon carbide sintered body that can withstand high temperatures. Filter 2 is shown in FIG.
As shown in FIG. 3, adjacent through-holes 4 are separated from each other by partition walls 3 which are porous and have a filtering function of a filter, and end faces 5 of the through-holes 4 are alternately plugged 6 like a checkered pattern so that a large number in the longitudinal direction. The wall flow honeycombs are arranged side by side and each constitute an independent flow path. Therefore, the exhaust gas passage is in one direction in the axial direction, and the filter section can be formed in the same manner as the divided section without particularly dividing.

In this embodiment, the filter 2 is rotated as shown in FIGS. 1 and 2, and the section members 7, 7 'are
It is fixed to.

As shown in FIG. 2, the section members 7, 7 'are fixed to face each other on an extension 19 of a flange of a cover member 18 of the main body 8. 20 is the filter section 1
7 is a mounting screw. Then, the skirt member 21 seals while slidingly contacting the surface 5 of the filter 2, and a predetermined filter section 17 (the area of the filter section ← →
). That is, in the filter 2 of this embodiment, the filter section 17 is not clearly defined, and its boundary is always moving. However, due to the characteristics of the wall flow honeycomb structure, since the exhaust gas passage is in one axial direction, the filter section 17 always stays at that position in an independent manner, as if it were divided without dividing. . The skirt member 21 that seals the section member 7 while sliding or approaching the surface 5 at the end face of the rotating filter 2 is preferably a soft, heat-resistant, and slippery skirt member. The fibers (brissles) are combined into a long brush having a width of 3 and used as the lower end of the section member 7. The filter 2 is driven by the small gear 12 from the internal gear 11 of the case 10 and rotates sequentially.

As shown in FIGS. 1 and 2, the filter 2 is housed in a filter case 10 with a cushion 9 made of alumina, silicon carbide fiber or the like interposed therebetween, and the case 10 is provided with an internal gear 11 on its inner periphery. In addition, there is a small gear 12 for driving this (a driving motor is not shown). The other end of the case 10 is supported by a plurality of rollers 13. Roller 13 is more than metal only
It is preferable to use a fluorine rubber or a silicone rubber which is at least partially excellent in heat resistance. That is, as an example of the roller 13, the outer ring 14 in contact with the case 10 is made of stainless steel having a low heat conductivity, and the heat resistance temperature between the outer ring 14 and the shaft 15 is 230.
Fluoro rubber 16 at ° C. is used. Therefore, the section member 7 blocks the dust-containing exhaust gas, constitutes the filter section 17, and incinerates and regenerates the particulate matter accumulated in the filter section 17, thereby continuously supplying a new filter.

FIG. 4 shows a filter section 1 in this embodiment.
7 (B + C) is shown as a graph. A + B
+ C indicates the surface area of the entire filter 2.

In the collection section A, the exhaust gas containing particulate matter (dust exhaust gas 32) is filtered, and the purified exhaust gas (dust exhaust gas 33) is discharged downstream. The amount of particulate matter 34 deposited by filtration increases with time.

The incineration section of section B is a section member 7b.
Thus, a filter section B independent of the filter 2 is formed. The air 22 is heated to 650 ° C. by the heater 24 from the downstream side of the exhaust gas, passes through the filter section B, and incinerates the particulate matter 34 in the filter section B (the flow of the heated air may be upside down). 35 is incineration ash.

In the backwash section C, air is sent from the downstream side of the exhaust gas at a wind pressure of 5 MPa or more by the section member 7c to backwash the inside of the filter section 17c. Filter 2 that has finished playing in filter section 17c
Return to start D.

Backwashed air 36 containing the incinerated ash obtained by heating the filter section B to incinerate the particulate matter 34 and the incinerated ash obtained by backwashing the filter section C to remove the incinerated ash 35
Is discharged downstream together with the exhaust gas 33. 30 in the figure
Is a valve of the section member 7b, and 31 is a section member 7c.
The valve.

In the above, the example in which the section member 7 is fixed and the filter 2 is continuously moved has been described.

As a more effective backwashing method with the above configuration,
(1) The valve 31 is closed, the valve 30 is opened, and the filter 2 is moved while the filter section B is continuously incinerated by the heater 24. When it moves to the full width of the filter section C,
(2) The movement of the filter 2 is stopped, the valve 30 is closed, and the valve 31 is closed.
Is opened to backwash the inside of the filter section C at once. Then, (1) and (2) are repeated. Then, the heat of combustion of the deposited particulate matter can be used for the next combustion, and the energy required for the heater 24 is greatly reduced. In addition, the amount of air used can be minimized by stopping the filter section C and jetting backwash air at once.

[0029]

Embodiment 2 In this embodiment, as shown in FIG. 5, the section member 7 of Embodiment 1 is reduced to one. That is, the section member 7 stops the movement of the filter 2, and (1) first, the air 22 sent from the pipe 23 is heated by the heater 24 to incinerate the inside of the filter section B. Then (2)
The heater 24 is stopped, and the air 22 sent from the pipe 23 is jetted at the same section member 7 to backwash the filter section B as the filter section C.
When the processes (1) and (2) are completed, the filter 2 is moved by the width of the section member 7. Then, (1) and (2) are repeated. In the figure, reference numeral 11 'denotes an external gear.

[0030]

Embodiment 3 This embodiment is shown in FIGS. This embodiment is characterized in that the filter 2 is fixed to the main body 8 and the section member is moved. That is, the filter 2 provided with the hole member 29 at the center is fixed to the main body 8 with the cushion 9 interposed therebetween. The center tube 26 is loosely inserted into the hole member 29.
Is provided. Section members 7, 7 'are disposed on the center tube 26 so as to face the same position in the vertical direction. The filter section 17 is regenerated by continuously rotating the section members 7, 7 'from the center tube 26. In this case, the section members 7 and 7 ′ rotate while slidingly sealing the end face 5 of the filter 2. A part of the section members 7 and 7 'is inscribed in the groove member 28 of the main body 8 together with the balance arm 27, and rotates stably. Reference numeral 25 denotes a screw for connecting the balance arm 27 to the section member 7 and the center tube 26.

In this example, since the filter section 7 moves, the heating air 22 for incineration is supplied from the pipe 23 to the heater 2.
4, the air enters the filter section 17 from the section 7 ′ in a direction opposite to the flow of the exhaust gas 32 → 33, and becomes the backwashed air 36 from which the incinerated ash has been separated. Then, the gas is discharged from the section member 7 through the center tube 26 together with the dust removal exhaust gas 33. At this time, backwashing is performed at the same time, and regeneration of the filter section 17 of the filter 2 is performed.

[0032]

[Embodiment 4] This embodiment is characterized in that a time difference is provided between the incineration and the backwash treatment of the embodiment 3. That is,
First, the section member 7 is stopped on the filter 2 fixed to the main body 8, and the heated air 22 from the heater 24 of the pipe 23 is heated.
To incinerate the filter section 17. Then, the heater 24 is stopped, and backwash air is sent from the pipe 23 at the same position (while the section member 7 is stopped) to blow. Then, rotate the center tube 26 so that the section members 7, 7 '
To move. That is, the section members 7, 7 'are not rotated continuously, but are moved intermittently at predetermined intervals. This movement is preferably performed using a ratchet using claws.

As shown in FIG. 8, the filter 2 of the second and fourth embodiments preferably has a section member 7 having 6 to 30 filter sections 17 having, for example, a tangerine bag-shaped cross section. A partition plate 37 having a width of about 2 mm is used for the partition of the bag-shaped filter section 17.
The skirt member 21 of the section member 7 fits and seals the partition plate 37.

The filter 2 of this embodiment has a partition plate 37
There is, and is interrupted by the section, not limited to the wall flow honeycomb filter described above, metal honeycombs that are wound or laminated crossing a corrugated sheet and another corrugated sheet,
Filters using ceramic fibers, open-cell porous ceramic blocks, and the like can be freely used as the filter 2.

A plurality of the particulate matter removing devices for diesel engine exhaust gas of the present invention can be used in parallel, or a new or conventionally known particulate matter removing device, a catalyst device, or the like is combined before or after the present device. Can be.

[0036]

As described in detail above, according to the present invention,
Various effects can be obtained as listed below. (1) Particulate matter (PM) of the entire filter can be incinerated by electric power for heating one filter section instead of the entire filter. (2) Since the filters divided or divided into a number of sections perform independent functions, only one filter may be used. (3) Since only one filter is required, the cost is reduced to 以下 or less, and the volume is reduced to 以下 or less in the conventional case that requires two filters. (4) Instead of switching after the filter is clogged, switching is performed in small increments or continuously, so that pressure loss is small and no load is applied to the engine. (5) Since the pressure loss due to clogging is small, a filter having a finer gap can be used, and the effect of removing particulate matter increases. (6) Since continuous regeneration is performed, the pressure loss is always constant and an excessive load is not applied to the engine. (7) The moving speed of the filter section and the temperature of the heater can be changed immediately in response to the deposited amount of particulate matter, that is, clogging, and the efficiency is extremely high.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing one embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view taken along line AA of FIG. 1;

FIG. 3 is a perspective view schematically showing a porous ceramic member used for the wall flow honeycomb filter shown in FIG.

FIG. 4 shows the relationship between filters and filter sections;
FIG. 4 is an explanatory diagram showing the relationship between the particles and particulate matter in a graph.

FIG. 5 is a perspective view of the second embodiment with a part cut away.

FIG. 6 is a perspective view in which a part of the third and fourth embodiments is cut away.

FIG. 7 is an explanatory longitudinal sectional view taken along the line AA of FIG. 6;

FIG. 8 is a plan view showing a filter section of a filter according to a fourth embodiment.

FIG. 9 is an explanatory diagram using two conventional filters.

[Explanation of symbols]

1. Particulate matter removal device (DPF) A. Collection section 2. Filter B. 2. Incineration section 3. Partition wall C. Backwash section Through hole 5. End face 6. Sealing 7. Section member 8. Main body 9. Cushion member 10. Case 11. Internal gear 11 'External gear 12 Pinion (small gear) 13. Roller 14. Outer ring 15. Axis 16． Rubber 17． Filter section 18. Lid 19. Extension of flange 20. Mounting screw 21. Skirt 22. Backwash air 23. Tube 24. Heater 25. Screw 26. Center tube 27. Balance arm 28. Groove member 29. Hole member 30. Valve of section member 7b 31. Valve of section member 7c 32. Dust-containing exhaust gas 33. Dedusting exhaust gas 34. Particulate matter (PM) 35. Incinerated ash 36. Backwashed air 37. Partition board

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroo Masaki 4-7-22 Migatadai, Nishi-ku, Kobe-shi, Hyogo F-term (reference) 3G090 AA02 BA04 CB11 CB18 4D058 JA32 JB03 JB06 JB25 MA15 MA41 MA48 SA08

Claims (5)

[Claims] An apparatus for removing particulate matter (DPF) from exhaust gas, such as a diesel engine, includes a ceramic wall-flow honeycomb, a nonwoven fabric filter, or a metal honeycomb filter that captures the particulate matter (PM) in a plurality of filter sections. It is a particulate matter removal device of the exhaust gas which is divided or divided in a filter section, and the particulate matter (PM) collected and accumulated in the filter section of the filter, from the exhaust gas downstream side, An apparatus for removing particulate matter from exhaust gas, wherein the apparatus is backwashed with air or the like in a direction opposite to the flow of the exhaust gas. 2. The particulate matter removing device comprises a rotating filter and a section member fixed to a main body.
The exhaust gas particulate matter removing apparatus according to claim 1, wherein the backwashing regeneration is performed intermittently or continuously in a filter section fixed to the main body. 3. The particulate matter removing device comprises a rotating filter and a section member fixed to a main body.
The particulate matter collected and deposited on the filter section A is
2. The apparatus for removing particulate matter from exhaust gas according to claim 1, wherein the apparatus is first incinerated in the filter section B and then backwashed in the filter section C with air or the like in a direction opposite to the flow of the exhaust gas, and the regeneration is continuously performed. 4. The particulate matter removing device comprises a filter fixed to a main body and a moving section member.
The apparatus for removing particulate matter from exhaust gas according to claim 1, wherein the backwash regeneration is performed intermittently or continuously in the moving filter section. 5. In the filter fixed to the main body, the particulate matter collected and deposited in the filter section constituted by the moving section members 7, 7 'is: (1) First, the filter sections 17, 17; And (2) then, in the same place, the filter section is backwashed with air or the like in a direction opposite to the flow of exhaust gas to separate incinerated ash, and regeneration is continuously performed. 2. The particulate matter removal device for exhaust gas according to claim 1.