JPH0710027Y2 - Particulate collection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a particulate trapping device provided in an exhaust gas passage of an engine for improving trapping efficiency, regeneration rate, durability and the like. .

<Prior Art> Exhaust gas from a diesel engine contains a large amount of particulates containing carbon fine particles as a main component. Then, for environmental protection, a device for collecting the particulates is attached to the exhaust gas passage.

Although there are various types of particulate trapping devices, for example, one in which a casing is provided in the middle of an exhaust gas passage and a ceramic filter having a honeycomb structure is fixed and filled in the casing is known.

In this device, particulates in the exhaust gas flowing from the upstream are collected by this filter and deposited on the filter. If the accumulated amount becomes too large, the exhaust pressure rises and the fuel consumption deteriorates. Therefore, it is necessary to burn and remove this particulate at an appropriate time.

To remove particulates by combustion, for example, an electric heater disposed upstream of the filter is usually operated, and the radiant heat of the heater ignites the particulates, which is then deposited on the downstream filter as an ignition source. A method of instantaneously burning particulates is used.

In this way, the filter from which the particulates are removed and regenerated collects the particulates again.

<Problems to be Solved by the Invention> In the particulate trapping device having the above configuration, since the trapped particulates are burned and removed at regular intervals as described above, the exhaust gas is not passed through the particulate trap during the period, It was discharged through the bypass. for that reason,
The collection function of the particulates was temporarily stopped, and the deterioration of the collection efficiency was unavoidable.

Further, in the particulate trapping device in which the filter is fixed and filled in the casing, it is difficult to uniformly heat the filter over the entire area when burning the particulate during regeneration of the filter. there were.
As a result, a part where the particulates are not burned remains, which reduces the regeneration efficiency of the filter, which deteriorates fuel consumption and requires frequent filter regeneration.

On the other hand, since the particulates are completely burned, if the heating time is extended, the temperature of the filter becomes extremely high locally, which may cause the filter to melt.

The present invention has been made in view of these points,
An object of the present invention is to provide a particulate trapping device which can continuously trap particulates without interruption and which has improved filter regeneration rate and durability.

<Means for Solving the Problems> In order to achieve the above-mentioned object, in the present invention, a thin plate-shaped filter that partially traverses an exhaust gas passage of an engine is rotatably held, and a driving unit that rotates the filter,
The particulate matter trapping device is provided with a heating means for regeneration that heats the filter outside the exhaust gas passage, and the filter is rotated intermittently.

<Operation> When the filter crosses the exhaust gas passage, particulates in the exhaust gas are collected by the filter. When the filter rotates and comes out of the exhaust gas passage, it is heated by the regeneration heating means to burn off the particulates and regenerate the filter.

<Embodiment> FIG. 1 shows an outline of a particulate trap device according to an embodiment of the present invention, and FIG. 2 shows the position of the particulate trap device in the exhaust system. .

As shown in FIG. 2, the particulate trapping device 1 is provided on the downstream side of the exhaust pipe 3 drawn out from the engine 2, for example, on the upstream side of the muffler 4.

The particulate collection device 1 is housed in a casing 5 that surrounds a part of the exhaust pipe 3, and a part of the exhaust pipe 3 is expanded in the casing 5, and the expanded diameter portion 3a
A disk-shaped ceramic filter 6 is rotatably supported around its central axis, a part of which crosses the axis. In this embodiment, nearly half of the ceramic filter 6 faces the exhaust pipe 3. The ceramic filter 6 has a thin plate shape in order to easily obtain a uniform temperature distribution and reduce thermal stress.

A gear 7 is provided around the ceramic filter 6, and a driving small gear 9 driven and rotated by a motor 8 is meshed with the gear 7. Therefore, by driving the motor 8, the ceramic filter 6 is rotated at a low speed through the meshing of the gears 9 and 7.

On the other hand, an electric heater 10 is provided as a regeneration heating means for the portion of the ceramic filter 6 outside the exhaust pipe 3.
It is desirable to provide the electric heater 10 immediately after the ceramic filter 6 has passed through the exhaust pipe 3 in order to save heating time.

As described above, in the particulate matter collecting device 1, the ceramic filter 6 moves across the exhaust pipe 3 to collect the particulates in the exhaust gas, and the ceramic filter 6 outside the exhaust pipe 3. Regeneration part B for heating
And have.

In this particulate trapping device, particulates in the exhaust gas are trapped by the ceramic filter 6 while the ceramic filter 6 is moving across the exhaust pipe 3.

Due to the rotation of the ceramic filter 6, the portion of the ceramic filter 6 that collects the particulates passes through the exhaust pipe 3 and reaches a position facing the electric heater 10.
The trapped particulates are heated and burned by 10. Since the ceramic filter 6 is rotating, the amount of particulates collected per time is small, and the heating and combustion can be easily performed. That is, it is easy to regenerate and heating is prevented. Further, since the amount of particulates collected per one time is small, there is no clogging, and this also facilitates regeneration.

The regenerated portion of the ceramic filter 6 is again exhaust pipe 3
Once inside, the above steps are repeated. These steps are carried out intermittently by observing the degree of collection of particulates.

The area of the portion of the ceramic filter 6 that crosses the exhaust pipe 3 is appropriately increased or decreased according to the speed of collection and regeneration.

Further, the heating means is not limited to the electric heater 10, but a means utilizing a burner, exhaust heat or the like can be adopted.

<Effects of the Invention> According to the particulate trapping device of the present invention, a thin plate filter that partially traverses the exhaust gas passage of the engine is rotatably held, and a driving unit that rotates the filter, A regeneration heating means for heating the filter outside the passage was provided, and the filter was intermittently rotated so that the collection by the filter and the regeneration of the filter proceed at the same time. , It is not necessary to suspend the collection function, the collection of particulates can be performed continuously, the collection efficiency of particulates is improved, and the amount of particulates adhering to the filter before regeneration is small. , Regeneration is facilitated and heating during regeneration is prevented. Further, since the filter is formed in a thin plate shape, the collection area is sufficiently secured, the exhaust pressure does not increase so much, and combustion at the time of regeneration can be uniformly performed in a short time, so that the generation of cracks is prevented as much as possible. Further, since the collecting part and the reproducing part are separated, the degree of freedom in design is increased.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a particulate trapping device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing the arrangement position in the exhaust system. In the drawings, 1 is a particulate trap, 3 is an exhaust pipe, 6 is a ceramic filter, 8 is a motor, and 10 is an electric heater.

Claims (1)

[Scope of utility model registration request] 1. A drive means for rotatably holding a thin plate-shaped filter that partially traverses an exhaust gas passage of an engine and a rotating means for rotating the filter, and a heating means for regeneration for heating the filter outside the exhaust gas passage. A particulate trapping device, comprising: the filter, wherein the filter is rotated intermittently.