JPH0515529Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a filter regeneration device that collects particulate matter contained in engine exhaust gas. More specifically, the present invention relates to an apparatus for regenerating a filter by forcibly heating the filter from the downstream side of the filter and burning and removing collected particulate matter (hereinafter referred to as collected particulate matter).

[Prior Art] Engine exhaust gas contains particulate matter, that is, soot and fine particles of hydrocarbons, sulfates, metals, etc. adsorbed on soot. Under operating conditions where the content of particulate is high, particulate matter is discharged to the outside, so a collector equipped with a heat-resistant filter for collecting particulate matter is installed in the engine exhaust passage to purify the exhaust gas. It is proposed to do so. However, when this filter is used for a long time, collected particulate matter accumulates on the filter, clogging the filter, increasing the ventilation resistance and reducing the collection efficiency.

Therefore, a technique has been proposed in which a heater or the like is installed upstream of this filter, and when the collected particulate matter accumulates above a certain level, it is heated to burn the particulate matter and regenerate the filter. There is a problem that the filter easily becomes overheated and the filter melts.

In order to solve this problem, a device has been proposed in which heated compressed air is introduced into the filter from the downstream side of the filter where the collected particulate matter is deposited to burn and remove the collected particulate matter. 13211).

In this device, two independent first and second exhaust gas flow paths are formed in the collector, and a flow path switching means for selectively switching between the two flow paths is provided at the exhaust gas convergence part. A heated compressed air outlet is provided on the downstream side of the filter with a relatively large distance from the exhaust gas outlet of the filter.

In the conventional device configured in this manner, the heated compressed air flows backward from the downstream side of the filter to the upstream side of the filter, so the filter has the advantage that it does not become overheated and does not melt. However, since the heated compressed air coming out of the outlet is introduced into the filter through the space on the downstream side of the filter, flow path switching means other than the filter,
There was a problem in which the stainless steel container and partition walls were heated by heated compressed air, resulting in a large loss of thermal energy.

In order to solve this problem, the present inventor proposed a filter instead of providing a flow path switching means for switching the flow of exhaust gas in the collector so that heated compressed air can be introduced into the filter even while the engine is running. He devised a regeneration device for particulate filters in which a heater case was rotatably provided with respect to the filter at a position facing the downstream side of the filter, and filed an application for registration of a utility model (Utility Model Application No. 1840-12).

In this regenerator, the surface of the heater case facing the filter is formed so as to partially cover the exhaust gas outlet of the filter, and the surface of the heater case facing the filter is provided with numerous holes for blowing heated compressed air into the filter. ing.

When regenerating the particulate filter, heated compressed air is introduced from the blow-off hole while rotating the heater case to heat the filter and burn the collected particulate. In this device, heated compressed air is introduced directly into the filter from the blow-off hole of the heater case, so it has the advantage of lower heat loss than the device described in JP-A-57-13211.

[Problems to be solved by the invention] However, when introducing heated compressed air into the filter, this conventional regeneration device generates heat through a small gap between the filter-facing surface of the heater case and the exhaust gas outlet of the filter. Compressed air easily leaked outside the filter on the downstream side, and there was still room for improvement in terms of reducing thermal energy loss.

The purpose of this invention is to reliably prevent heated compressed air from leaking to the downstream side of the filter, further reduce the thermal energy loss of the heated compressed air, and efficiently and reliably remove collected particulate matter. An object of the present invention is to provide a filter regeneration device.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the present invention will be explained based on FIG. 1, which corresponds to an embodiment.

The present invention consists of a particulate collector 2 installed in an exhaust passage 1 of an engine, a filter 4 installed in this collector 2, and heated compressed air for burning and removing the collected particulate from the downstream side of the filter 4. This is an improvement of a particulate filter regenerating device, which is equipped with an introduction means for introducing the particulate filter into the filter 4.

Its characteristic configuration is that the introducing means includes a heater case 6 rotatably provided with respect to the filter 4 at a position facing the downstream side of the filter 4, and the surface of the heater case 6 facing the filter 4
is formed to cover part of the exhaust gas outlet of the
A large number of holes are provided on the surface facing the filter to blow out heated compressed air into the filter, and a heater case 6 is provided with a small gap between the surface facing the filter and the exhaust gas outlet, and the heater case 6 is provided with a small gap between the surface facing the filter and the exhaust gas outlet, and the heater case 6 is provided with a small gap between the surface facing the filter and the exhaust gas outlet. A sealing material 32 is provided to prevent compressed air from leaking to the outside of the downstream side of the filter 4.

[Function] When the heated compressed air is jetted directly from the hole 8 toward the filter 4 while rotating the heater case 6,
The heated compressed air is passed through the filter 4 by the sealing material 32.
Particulate matter introduced into a filter 4 without leaking from the outside on the downstream side thereof and deposited on the filter 4 is efficiently burned and removed.

[Example] Next, an example of the present invention will be described in detail based on the drawings.

As shown in FIG. 1, a particulate collector 2 is provided in an exhaust passage 1 of an engine. A honeycomb-shaped filter 4 is provided within the collector 2. As shown by the arrow in the figure, the exhaust gas E passes through the honeycomb-shaped passage 4b defined by the wall 4a of the filter 4 from below the collector 2, passes over the collector 2, and is released to the outside air. Ru. Particulate matter P in the exhaust gas is deposited at the inlet of the filter 4, that is, on the upstream side.

A heater case 6 is provided in the collector 2 at a position opposite the outlet of the filter 4, i.e., the downstream side, so as to be rotatable with respect to the filter 4, and is rotated by, for example, a worm wheel 10 and a worm 12. The heater case 6 is formed as a hollow body with an L-shaped cross section, and the surface facing the filter 4 is formed in a fan shape so as to cover about one-quarter of the exhaust gas outlet of the filter 4 as shown in Fig. 2, and a number of holes 8 for blowing heated compressed air into the filter are provided through the heater case 6. The surface of the heater case 6 facing the filter and the exhaust gas outlet of the filter 4 are provided with a small gap. A pipe 14 supported on the stationary side is inserted into the heater case 6 via a bearing 16 or the like. An air source 18 for supplying boost air or compressed air or the like is connected to the pipe 14, and an electromagnetic valve 20 is provided midway.

A heater 22 is arranged in the heater case 6 along the fan shape. The heater 22 is connected to a power source 26 via a rotary joint 24 or the like, and a switch 28 is provided in the middle. A controller 30 for operating the solenoid valve 20 and switch 28 is connected.

The characteristic configuration of this embodiment is that the compressed air jetted out from the hole 8 of the heater case 6 flows to the outside of the filter 4 on the downstream side in a small gap between the exhaust gas outlet of the filter 4 and the surface of the heater case 6 facing the filter. A sealing material 32 is provided to prevent leakage. The sealing material 32 is a heat-resistant member, and in this example is ceramic paper. As shown in FIG. 3, the sealing material 32 is attached to the fan-shaped heater case 6.
The rotating part is punched out, and a thin reinforcing part 32 is formed so as not to block the honeycomb-shaped passage 4b of the filter 4.
A will be constructed. The peripheral edge of the sealing material 32 is sandwiched between the flanges 2a and 2b of the collector 2, as shown in FIG.

In the regenerator configured in this manner, when the solenoid valve 20 and switch 28 are opened by the controller 30, boost air or compressed air is introduced into the heater case 6 from the air source 18 via the pipe 14 and is supplied to the heater 22. Electricity is applied to heat the boost air or compressed air.

When the heater case 6 is rotated by the worm 12 and the worm wheel 10, the heated air H
is ejected from the hole 8 and flows from the downstream side to the upstream side of the filter 4. Here, the sealing material 32 is attached to the filter 4.
Since it is provided in the gap between the exhaust gas outlet of the heater case 6 and the surface facing the filter, the heated air H
does not leak outside the downstream side of the filter 4, and most of the heated air flows through the honeycomb-shaped passage 4.
flows into b.

When the heated air H flows into the honeycomb-shaped passage 4b, the collected particulate matter P is combusted and the upstream side of the filter 4 generates heat, but since the heated air H is constantly flowing backward from the downstream side to the upstream side, the high heat due to combustion is generated. is not transmitted downstream. Further, since the exhaust gas E does not flow into the filter 4 into which the heated air H is flowing, this portion is not heated, and as a result, the filter 4 does not become overheated, and its melting damage and cracks do not occur.

Once the removal of the collected particulate matter P is completed,
The solenoid valve 20 and switch 28 are closed, and the rotation of the heater case 6 is stopped. As a result, the exhaust gas E passes through the filter 4 and is discharged from the exhaust passage 1 to the outside air.

In the above example, the sealing material 32 is attached to the collector 2 with a flange, but the sealing material 32 may be attached to the periphery of the bottom surface of the heater case 6 instead of being attached with a flange.

Further, the shape of the heater case 6 and the corresponding shape of the sealing material 32 shown in the above example are merely examples, and the present invention is not limited thereto.

Further, the sealing material 32 is not limited to ceramic paper, but may be any heat-resistant sheet member, and if it is made of a rigid material, there is no need to provide the reinforcing portion 32a.

[Effects of the invention] As mentioned above, in the conventional device, the space on the downstream side of the filter was also heated with heated air, but in the present invention, the heater case is placed opposite the downstream side of the filter with a small gap. Since a sealing member is provided in the gap, leakage of heated compressed air to the downstream side of the filter is reliably prevented, the thermal energy loss is further reduced, and the collected particulate can be removed efficiently and reliably. , filter clogging can be eliminated by regenerating the filter.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a reproducing apparatus according to an embodiment of the present invention. Second
The figure is a sectional view taken along the line -- in FIG. FIG. 3 is a plan view of the sealing material. DESCRIPTION OF SYMBOLS 1... Exhaust passage, 2... Particulate matter collector, 4... Filter, 6... Heater case (heated compressed air introducing means), 8... Hole, 18... Air source,
20...Solenoid valve, 22...Heater, 32...Sealing material.

Claims (1)

[Claims for Utility Model Registration] A particulate matter collector 2 provided in the exhaust passage 1 of the engine, a filter 4 provided in the collector 2, and combustion of the particulate matter collected from the downstream side of the filter 4. A regenerating device for a particulate filter, comprising an introducing means for introducing heated compressed air to be removed into the filter 4, wherein the introducing means is rotated with respect to the filter 4 to a position facing the downstream side of the filter 4. The heater case 6 includes a heater case 6 that can be provided, a surface of the heater case 6 facing the filter is formed to cover a part of the exhaust gas outlet of the filter 4, and heated compressed air is blown into the filter onto the surface facing the filter. The heater case 6 is provided with a small gap between the filter-opposed surface and the exhaust gas outlet, and the heated compressed air is passed to the outside of the downstream side of the filter 4 in this gap. A regenerating device for a particulate filter, characterized in that a sealing material 32 is provided to prevent leakage of the particulate filter.