JPH0719026A - Diesel particulate filter - Google Patents

Abstract

PURPOSE:To provide a small sized filter by using a porous ceramics raw material and closing designated positions of the entrance and the exit of passages of a honeycomb shaped block material having a plurality of parallel passages. CONSTITUTION:A diesel particulate filter is constituted by attaching sealing plugs 22 and closing plugs 23 to a filter block 2 formed in honeycomb shaped and having a plurality of parallel passages by using a porous ceramics raw material so as to filter exhaust gas and also heater wires 3 are passed through the passages provided with the closing plugs 23 and these heater wires 3 are placed in connection parallely. Electric power from an electric power generator 5 or a battery 6 is supplied by a control device 4 and sediments are heated and incinerated by the heat of the heater wires 3 in order to treat the sediments collected by the filtration of the exhaust gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel particulate filter for collecting particulates in exhaust gas of a diesel engine.

[0002]

2. Description of the Related Art In a diesel engine, fuel is injected into high-temperature air by adiabatic compression, and the combustion is carried out. Since it is a heterogeneous combustion, the emission of carbon monoxide and hydrocarbons is small, but Nitrogen oxides and particulates
There is a problem that a large amount of waste is emitted.

In order to prevent the release of such particulates to the atmosphere, a particulate filter has been developed which is equipped with a filter in the exhaust passage to filter the exhaust gas and purify it.

[0004]

When the volume of the particulate filter as described above is increased, the exhaust gas flow path resistance is reduced and the life per filter is increased, but on the other hand, There is a possibility that the temperature distribution changes greatly when the filter is regenerated due to the incineration of the deposits, and the filter itself may be partially melted or damaged.

Further, if the filter volume is increased, the cost is increased and the mountability on the vehicle is deteriorated.

The present invention has been made in view of the above problems, and an object thereof is to reduce the capacity of a filter that collects and incinerates particulates in exhaust gas, and at the same time, regenerates the same. It is an object of the present invention to provide a diesel particulate filter which is intended to be promptly processed.

[0007]

In order to achieve the above object, according to the present invention, there is provided a diesel particulate filter which collects particulates in exhaust gas of a diesel engine and incinerates them by electric heat. A honeycomb block material having a large number of parallel channels made of a porous ceramic material, a sealing plug for alternately sealing the upstream ends of the parallel channels of the block material, and a channel without the sealing A closing plug for closing the downstream end of the heater, a heater wire inserted through the flow path having the closing plug, and an energization control means for connecting the heater wires in parallel to energize them for heating. -A Zell particulate filter is provided.

[0008]

The filter block for collecting the particulates is formed of a porous ceramic material into a honeycomb shape, and exhaust gas is filtered by using a sealing plug or a closing plug, so that the filter becomes small in size, and also for heating. Since a large number of heater wires are connected in parallel, the entire filter is uniformly and rapidly heated when energized, and a regeneration process is performed.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is an explanatory view showing the construction of an embodiment of a diesel particulate filter according to the present invention, and FIG. 2 is a sectional view of a filter block used in this embodiment.

In these drawings, 1 is a filter case.
And a flange 11 connected to the exhaust pipe of the engine at the upstream end and a mounting plate for mounting the exhaust tail pipe at the downstream end. 12 are provided.

Reference numeral 2 is a cylindrical filter block, the outer peripheral wall of which is covered with a heat shield 21 and is housed in the central portion 10 of the filter case 1. The filter material is, for example, heat-resistant porous ceramics. The material is used and formed in a honeycomb shape having a large number of parallel flow paths. Then, every other upstream inlet is sealed by a sealing plug 22, and the outlets of the adjacent unsealed flow paths are closed by a closing plug 23 made of fiber ceramics. Also,
A heater wire 3 made of heat-resistant steel is laid in each of the honeycomb-shaped flow paths having the stoppers 23, and the upstream / downstream ends thereof are wire mesh-shaped electric wires provided in front / after of the filter block 2. They are each welded to the conductors 31 and all joined in parallel connection. The heater wire 3 has a positive temperature coefficient of resistance, and the resistance values are equal to each other, but the resistance value of the portion near the outside of the filter block 2 is small. Alternatively, the resistance value of the portion close to the center may be increased to increase the heat generation amount on the outside when energized.

Reference numeral 4 is a control device for energizing the heater wire 3 of the filter block 2, and the electric power from the vehicle-mounted generator 5 or battery 6 serving as a power source is passed through the wiring 32 to the upper / downstream electric conductor 31, It is led to 31 and is supplied to each heater wire 3 connected in parallel to generate heat.

Next, the operation of this embodiment thus constructed will be described. Exhaust gas from the engine is flange 11
When introduced into the filter case 1 through the exhaust gas, the exhaust gas flows into the flow path of the filter block 2 in the honeycomb-shaped flow path without the sealing plug 22.

Then, the gas component in the exhaust gas passes through the porous wall material of the flow path to be guided to the adjacent flow path, flows from the opened outlet toward the mounting plate 12, and is discharged to the atmosphere. Further, the particulates in the exhaust gas are collected by the porous wall material and deposited on the wall surface.

Then, the electric power from the generator 5 or the battery 6 is supplied to a large number of heater lines 3 connected in parallel via the wirings 32 and 32 and the electric conductors 31 and 31, respectively. Generates heat and raises the temperature of the flow path that is installed, and heats the deposit to, for example, about 600 ° C. to incinerate it.

In this case, since the heater wire 3 is alternately passed through the flow passages of the cylindrical filter block 2, the respective flow passages are uniformly heated, the temperature rises quickly, and they are connected in parallel. Further, since the heater wire 3 has a positive temperature coefficient of resistance, the resistance value of the heater wire in the high temperature portion becomes high, the current decreases, and a uniform temperature distribution can be obtained.

Although the present invention has been described with reference to the above embodiments, various modifications can be made within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the gist of the present invention.

[0018]

According to the present invention as in the above embodiments,
A honeycomb filter block made of a porous ceramic material is used as a filter for collecting particulates, and a large number of parallel channels are separated by sealing plugs and closing plugs, and exhaust gas is filtered to incinerate. As a result, a compact and compact filter can be obtained, and since the heater wires for heating are distributed and arranged in parallel and connected in parallel, uniform heating can be performed promptly and regeneration processing can be speeded up. There is an advantage. Further, in the present invention, since the metal wire having the positive resistance temperature coefficient is used for the heater wire, there is an effect that the temperature distribution can be made uniform.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of a diesel particulate filter according to the present invention.

FIG. 2 is a cross-sectional view of a filter block used in this embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Filter case 2 ... Filter block 3 ... Heater wire 4 ... Control device 22 ... Sealing plug 23 ... Closing plug 31 ... Electrical conductor

Claims (3)

[Claims] Claim: What is claimed is: 1. A diesel particulate filter for collecting particulates in exhaust gas of a diesel engine and incinerating the same by electrothermal heating, comprising a honeycomb-like structure having a large number of parallel flow paths made of a porous ceramic material. A block material, a sealing plug for alternately sealing the upstream ends of the parallel flow paths of the block material, a closing plug for closing the downstream end of the flow path without the sealing, and a flow path having the closing plug. A diesel particulate filter comprising: a heater wire inserted through the heater wire; and an energization control means for energizing and heating each of the heater wires connected in parallel. 2. The heater wire according to claim 1, wherein the heater wire is a metal wire having a positive temperature coefficient of resistance.
Zel particulate filter. 3. The energization control means arranges metal meshes made of heat-resistant metal on the upstream and downstream parts of the block material, and welds each end of the heater wire to energize. The diesel particulate filter according to claim 1.