JP2803470B2 - Separate type diesel particulate filter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adiabatic diesel particulate filter device for removing particulate solids (particulates) such as black smoke in an exhaust system of a diesel engine.

[0002]

2. Description of the Related Art Conventionally, it has been considered to equip a diesel particulate filter device in an exhaust system of a diesel engine in order to remove particulate solids such as black smoke. The conventional diesel particulate filter device is configured as shown in FIGS. 2 to 5, FIG. 2 is a schematic side view showing a main part of the diesel particulate filter device, and FIG. FIG. 4 is a schematic block diagram showing another example of the equipment state, and FIG. 5 is a graph showing the particulate combustion regeneration operation.

As shown in FIGS. 2 to 4, in a diesel particulate filter device S interposed in an exhaust gas passage EX of a diesel engine, a front case 1,
In a case C formed by the center case 8 and the rear case 11, a filter 7 for collecting particulates in exhaust gas is built. The front case 1 and the center case 8 and the center case 8 and the rear case 11 are fixed by bolts 5 and 10 via gaskets 4 and 9, respectively, and the filter 7 is moved from the downstream end of the front case 1 to the center case 8. Through the rear case 11
To the upstream end.

[0004] The filter 7 has a supporter mesh 6 wound on the outer periphery in the passage radial direction, and is supported by the case C via the supporter mesh 6 in the passage radial direction.
The filter 7 is fitted into the center case 8 from the upstream side, and the flange portion 8 at the downstream end of the center case 8.
A and the plate 3 ′ of the front case 1 are sandwiched in the passage axial direction.

[0005] The filter 7 is formed of a carrier such as cordierite.
Particulate burning means B is provided to burn the particulates collected by the filter 7 when necessary. The particulate combustion means B includes the heater 2 and the secondary air supply path 17.

That is, the heater 2 is provided so as to face the upstream end of the filter 7, and a predetermined current is supplied from a power source at a predetermined time, so that the filter 7 is heated to, for example, 500 ° C.
It is configured to be able to heat to a degree. The secondary air supply passage 17 is connected to the upstream end of the front case 1 from the side, and the combustion air is supplied at a predetermined timing by the secondary air supply passage 17. ing.

Heating by heater 2 and secondary air supply path 17
The supply of combustion air is performed according to the characteristics shown in the time chart of FIG. That is, when the amount of accumulated particulates in the filter 7 reaches a predetermined state, the entrance of the exhaust gas to the filter device S is shut off, and the heater 2 is turned on from time T0 to perform preheating by the heater 2.

As a result, the temperature of the filter 7 becomes 500 °
At time T1, the filter 7
When the temperature reaches 500 ° C., the secondary air supply from the secondary air supply path 17 is started, and particulate combustion in the filter 7 is started, and the combustion is sequentially performed from the upstream side to the downstream side of the filter 7. Propagate. Then, even after the combustion is started, the after-heat by the heater 2 is performed at the time T so that the entire particulates of the filter 7 are burned.
2, the heater 2 is turned off at time T2.

The secondary air is supplied from the secondary air supply passage 17 until the particulates in the filter 7 are completely burned. When the supply of the secondary air is cut off at time T3, the particulates burn. It ends sequentially from the upstream side. As a result, the particulates adhering to the filter 7 are almost completely removed, and the filter 7 is regenerated to a state in which the particulates are not collected, and the temperature gradually decreases.

It has been considered to equip the diesel particulate filter device S performing such an operation, for example, in a state shown in FIGS. In the structure shown in FIG. 3, a pair of diesel particulate filter devices S
1, S2 are provided in parallel with the exhaust gas passage EX. A valve V1 is provided at an upstream branch portion of the diesel particulate filter devices S1 and S2. Further, although the downstream side of the diesel particulate filter devices S1 and S2 is joined, the exhaust may be independently discharged without joining the downstream side.

The valve V1 is a switching valve configured to open one of the filter devices S1 and S2 and close the other, and the operation of the valve V1 causes any one of the diesel particulate filter devices S1 and S2 to operate. The exhaust path can be selectively formed through either of them. The switching of the valve V1 is performed every time when one of the collecting operations of the diesel particulate filter devices S1 and S2 is in a predetermined particulate accumulation state, and is closed by the valve V1 to perform the collecting operation. On the other hand, regeneration of the filter 7 is performed by burning the accumulated particulates.

In the structure shown in FIG. 4, the diesel particulate filter device S is provided with a bypass P via a valve V1. The valve V1 is switched during the regeneration of the filter 7 in the diesel particulate filter device S. The exhaust gas flows through the bypass P.

[0013]

By the way, in such a conventional diesel particulate filter device S, since the heater 2 is provided at a position upstream of the filter 7, the heat of the heater 2 is efficiently transmitted to the filter 7. However, there is a problem that the preheating time becomes longer and the regeneration efficiency of the filter cannot be increased more than necessary.

In order to obtain a sufficient processing capacity,
Since the size of the filter 7 increases and the length in the flow direction also increases, a difference in thermal expansion occurs between the upstream side and the downstream side, and there is also a problem that problems such as cracks are likely to occur. The present invention has been devised in view of the above-described problems, and increases the regeneration efficiency of a filter in a diesel particulate filter device, shortens the preheating time, and reliably prevents cracks in the filter. An object of the present invention is to provide a separate diesel particulate filter device that can be used.

[0015]

[0016]

Means for Solving the Problems] Therefore, the separate diesel particulate filter apparatus of the present invention according to claim 1, and interposed a casing in an exhaust gas passage of a diesel engine, is built in the casing an exhaust gas In a diesel particulate filter device comprising a filter for collecting particulates therein and a particulate combustion means built in the case for burning the particulates collected by the filter, an intermediate portion of the case An exhaust inlet is provided at the end of the case, a plurality of exhaust outlets are provided at an end of the case, and the filter portions are respectively disposed in flow paths from the exhaust inlet to the exhaust outlets, and the particulate combustion is performed. That the heat generating portion of the means is disposed between the exhaust inlet and the filter portion. It is a symptom.

[0017] Incidentally, as described in claim 2, the exhaust inlet of the above, it is desirable that the secondary air supply passage for introducing the secondary air for burning the particulates are connected.

[0018]

[0019]

[Action] In separate diesel particulate filter apparatus of the present invention described in claim 1 described above, the exhaust gas is guided to a plurality of filter portions that are divided from the exhaust inlet of the case middle, in the exhaust gas Is collected and discharged from a plurality of exhaust outlets formed at the end of the case. When the particulates collected by the filter portions are burned by the particulate combustion means, the heat generated by the particulate combustion means disposed between the exhaust inlet and the filter portion causes each of the filter portions to be burned. At the same time, combustion starts simultaneously from the upstream end, and combustion proceeds simultaneously toward the downstream end, and is completed in a short time.

If a secondary air supply path for introducing secondary air for burning particulates is connected to the exhaust port as described in claim 2 , each of the filter portions is provided. When the collected particulates are burned by the particulate burning means, secondary air for burning the particulates is introduced through a secondary air supply path connected to the exhaust inlet.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view showing an essential part of a separate diesel particulate filter device according to an embodiment of the present invention. The separate type diesel particulate filter device of the present embodiment is generally installed in the exhaust system of a diesel engine in a state shown in FIGS. 3 and 4 in substantially the same manner as in the conventional example, and according to the characteristics shown in FIG. The collection and the combustion regeneration are performed alternately.

In this embodiment, as shown in FIG. 1, the filter 7 for collecting particulates in the exhaust gas is divided into a pair of filter portions 71 and 72, and the flow path of the exhaust gas is divided into a pair. It is divided and formed so as to be guided to the filter portions 71 and 72, respectively. Note that the length of the filter portions 71 and 72 is set to about half of the length of the conventional filter portion 7.

That is, the exhaust inlet 21 is provided in the middle of the case C.
Are provided, and a pair of exhaust outlets 22 and 23 are provided at both ends of the case C, and filter portions 71 and 72 are provided in flow paths from the exhaust inlet 21 to the exhaust outlets 22 and 23, respectively. . Also, the filter parts 71, 7
2 are disposed so that the upstream ends thereof face each other, and a heater 2 as a heat generating portion of the particulate combustion means B is disposed between the upstream ends of the filter portions 71 and 72.

That is, the exhaust port 21 and the filter portion 7
The heater 2 is disposed between the heater 1 and the heater 72. The filter portions 71 and 72 are fitted into the cylindrical case C with their outer peripheries covered by the support mesh 6. Further, a secondary air supply passage 17 for introducing secondary air for burning particulates is connected to the exhaust inlet 21.

Since the adiabatic diesel particulate filter device as one embodiment of the present invention is configured as described above, in the configuration shown in FIG. 3 or FIG.
At a predetermined timing according to the characteristics shown in FIG. 5, the particulate collection operation and the regeneration operation of the filter 7 (71, 72) by the combustion of the particulates are performed alternately.

That is, during the trapping operation, the exhaust gas is guided to the pair of divided filter portions 71 and 72, respectively, and particulates in the exhaust gas are collected.
At the time of the regeneration operation, the filter portions 71, 72 are generated by the heater 2 as a heat generating portion of the particulate combustion means B disposed between the upstream ends of the filter portions 71, 72.
Is heated at the upstream end.

When the filter portions 71 and 72 are heated to a predetermined temperature and air is supplied from the secondary air supply passage 17,
The particulates collected in each of the filter portions 71 and 72 start burning. Then, in each of the filter portions 71 and 72, combustion proceeds simultaneously from the upstream end to the downstream end, and is completed in a short time.

That is, since the filter 7 is divided into a pair of filter portions 71 and 72, the burning of the particulates is completed in about half or less. Preheating is also performed in about half the time. Further, since the length from the upstream end to the downstream end of the filter portions 71 and 72 is reduced by half compared to the related art, the filter 7
Is large, the difference in thermal expansion between the upstream side and the downstream side, which is generated, becomes small, and generation of cracks and the like is avoided.

In this embodiment, the case C is formed in substantially the same shape as the conventional case, but the shape of the case C is not limited to this. That is, the exhaust inlet 21
And two exhaust passages branching from the filter to a pair of exhaust outlets 22 and 23 are provided. Each exhaust passage is provided with two divided filter portions 71 and 72, and these filter portions 71 and 72 are provided.
If the heater 2 is provided as a heating unit between
Case C may have any shape.

It is also conceivable to divide the filter 7 into three or more filters.

[0031]

[0032]

As described above in detail , according to the separate type diesel particulate filter device of the first aspect, the case interposed in the exhaust gas passage of the diesel engine and the exhaust gas contained in the case are provided. In a diesel particulate filter device comprising a filter for collecting particulates of the above and a particulate combustion means built in the case and burning the particulates collected by the filter, an intermediate portion of the case is provided. An exhaust inlet is provided, a plurality of exhaust outlets are provided at an end of the case, and the filter portions are respectively disposed in flow paths from the exhaust inlet to the exhaust outlets, and the particulate combustion means is provided. Simple configuration in which the heat generating portion is disposed between the exhaust inlet and the filter portion , There is an advantage that the regeneration efficiency of the filter is increased.

Also, there is an advantage that the preheating time is shortened and the occurrence of cracks can be reliably prevented. Furthermore, as described in claim 2 , the secondary air supply path for introducing the secondary air for burning the particulates is configured to be connected, so that the particulates are burned from the exhaust inlet. Is sufficiently supplied, the combustion is performed smoothly and reliably, and the above-described effects can be more reliably obtained.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a main part of an adiabatic diesel particulate filter device of the present invention, with a part thereof cut away.

FIG. 2 is a schematic longitudinal sectional view showing a main part of a conventional diesel particulate filter device, partially cut away.

FIG. 3 is a schematic configuration diagram showing an example of an installed state of a conventional diesel particulate filter device.

FIG. 4 is a schematic configuration diagram showing another example of an installed state of a conventional diesel particulate filter device.

FIG. 5 is a time chart and a graph showing a particulate combustion regeneration operation of a conventional diesel particulate filter device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Front case 2 Heater as a heating part of particulate combustion means 3 Inner case supporter 3 'plate 4 Gasket 5 Bolt 6 Supporter mesh 7 Filter 8 Center case 9 Gasket 10 Bolt 11 Rear case 17 Secondary air supply path 21 Exhaust inlet 22, 23 Exhaust outlet 71, 72 Filter part B Particulate combustion means EX Exhaust gas passage P Bypass S, S1, S2 Diesel particulate filter device V1 Valve

Claims (2)

(57) [Claims] 1. A case interposed in an exhaust gas passage of a diesel engine, a filter built in the case for collecting particulates in exhaust gas, and a filter built in the case and collected by the filter. In a diesel particulate filter device provided with particulate combustion means for burning curated, an exhaust inlet is provided at an intermediate portion of the case, and a plurality of exhaust outlets are provided at an end of the case, and the exhaust The filter portion is disposed in a flow path from an inlet to each of the exhaust outlets, and a heat generating portion of the particulate combustion means is disposed between the exhaust inlet and the filter portion. A separate type diesel particulate filter device. To wherein said exhaust inlet, wherein the secondary air supply passage for introducing the secondary air for burning the particulates are connected, separate diesel particulate filter of claim 1, wherein apparatus.