JPH06129230A - Engine exhaust emission control device - Google Patents

Abstract

PURPOSE:To reduce the clogging of a purifying filter so as to enhance the service lift of the purifying filter by providing an exhaust gas swirling chamber between a swirl induction part and the purifying filter, and by providing an electrical heater part along the inner peripheral surface of an exhaust gas swirling chamber. CONSTITUTION:A purifying filter 3 is stored in a cylindrical exhaust purifier 2 located in an engine exhaust passage 1. A swirl induction part 5 is provided in an air intake port 4 formed in one end part of the exhaust gas purifier 2. An electrical heater part 8 is provided along the inner peripheral surface 7 of an exhaust gas swirling chamber 6 provided between the swirl induction part 5 and the purifying filter 3. Exhaust gas 13 is turned into a swirl stream through the swirl induction part 5, and is swirled in the swirling chamber 6. Due to difference in centrifugal force, particulate having a specific weight larger than that of gas components are forced outward in the swirling exhaust gas, and is collected around the inner peripheral surface 7 of the swirling chamber 6, and are burnt by the electrical heater part 8. Thus, it is possible to reduce the clogging of the purifying filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine exhaust gas purification device, and more particularly to a device capable of reducing clogging of a purification filter.

[0002]

2. Description of the Related Art As a conventional technology of an engine exhaust gas purification apparatus, there is one shown in FIG. Like the present invention, it has the following basic structure. That is, a cylindrical exhaust gas purifier 102 is provided in the exhaust path 101 of the engine, and the exhaust gas purifier 102 accommodates the purification filter 103. The purification filter 103 is a ceramic filter having a honeycomb structure. The purification filter 103 includes a plurality of exhaust passages 118 therein, alternately closes a lower end portion 119 and an upper end portion 120 of the exhaust passages 118, and exhaust passages 118 adjacent to the exhaust passages 118.
When passing through the porous partition walls 121, the particulates in the exhaust gas are captured on the surface of the porous partition walls 121 to purify the exhaust gas.

By the way, in this way, the purification filter 103
In the exhaust gas purification device having a structure for trapping particulates with the purifying filter 10 by the trapped particulates.
3 may become clogged and become unusable in a short period of time. However, in this conventional technique, the purification filter 103
It does not have any means to reduce the clogging. In order to reduce clogging of the purification filter 103, it is also considered to provide a heating wire around the purification filter 103, heat the heating wire at the time of clogging, heat the purification filter 103, and incinerate the particulates. However, in this case, the purification filter 103 may be damaged by heating.
For example, when the purification filter 103 is the ceramic filter described above, cracks are generated by heating.

[0004]

In the above-mentioned conventional technique, the purification filter 103 is not provided with means for reducing the clogging of the purification filter 103, even though the purification filter 103 is clogged in a short period of time.
03 has a short life. An object of the present invention is to provide an engine exhaust gas purification device that can reduce clogging of a purification filter.

[0005]

[Means for Solving the Problems]

(First Invention) As shown in FIGS. 1 to 3, the first invention provides a cylindrical exhaust purifier 2 in an exhaust path 1 of an engine, and the exhaust purifier 2 accommodates a purification filter 3 therein. The exhaust emission control device for an engine configured as described above is characterized in that it is configured as follows.

That is, the swirl guide portion 5 is provided at the exhaust introduction port 4 provided at one end of the exhaust gas purifier 2, and the exhaust swirl chamber 6 is provided between the swirl guide portion 5 and the purification filter 3.
Is provided along the inner peripheral surface 7 of the exhaust swirl chamber 6
Is provided.

(Second Invention) As shown in FIG. 4, the second invention is a cylindrical exhaust purifier 2 in the exhaust path 1 of the engine.
The exhaust gas purifying device for an engine, which is configured by housing the purifying filter 3 in the exhaust gas purifier 2, is characterized as follows.

That is, an exhaust throttle chamber 10 having an air ejection portion 9 is provided between the exhaust introduction port 4 provided at one end of the exhaust gas purifier 2 and the purification filter 3, and the air ejected from the air ejection portion 9 is provided. With the wind pressure of the air 11 swirling along the inner peripheral surface 12 of the exhaust throttle chamber 10, the air jetting portion 9 is oriented so that 11 swirls along the inner peripheral surface 12 of the exhaust throttle chamber 10.
The exhaust 13 passing through the exhaust throttle chamber 10 is configured to be throttled to the central portion of the exhaust throttle chamber 10, and the electric heating portion 14 is arranged at the central portion of the exhaust throttle chamber 10.

[0009]

[Action]

(First Invention) As illustrated in FIG. 1, the exhaust gas 13 introduced from the exhaust gas introduction port 4 of the exhaust gas purifier 2 becomes a swirl flow in the swirl guide portion 5 and swirls in the exhaust gas swirl chamber 6. In the swirling exhaust gas 13, particulates having a larger specific gravity than the gas component are pushed out due to the difference in centrifugal force, are collected near the inner peripheral surface 7 of the exhaust gas swirling chamber 6, and are incinerated in the electric heating section 8. In this way, the particulates in the exhaust gas 13 are incinerated in advance before reaching the purification filter 3, so that clogging of the purification filter 3 is reduced.

(Second Invention) As illustrated in FIG. 4, the exhaust air 13 passing through the exhaust throttle chamber 10 is exhausted by the wind pressure of the air 11 swirling along the inner peripheral surface 12 of the exhaust throttle chamber 10. Squeezed into the center of. Therefore, the particulates contained in the exhaust gas 13 are also collected in the central portion of the exhaust throttle chamber 10 and incinerated in the electric heating section 14. In this way, the particulates in the exhaust gas 13 are incinerated in advance before reaching the purification filter 3, so that clogging of the purification filter 3 is reduced. Moreover, the air 13 is discharged from the air injection unit 9 to the exhaust 13.
Is abundantly supplied, the oxidation of CO, HC, etc. in the exhaust 13 is promoted.

[0011]

The first and second inventions have the following effects and advantages. Since the particulates in the exhaust gas are incinerated in advance before reaching the purification filter, clogging of the purification filter is reduced. Therefore, the life of the purification filter is extended. Since the purification filter is not heated, there is no damage to the purification filter due to heating.

Further, the second invention also has the following effects. Since a large amount of air is supplied to the exhaust from the air injection unit,
Oxidation of CO, HC, etc. in the exhaust gas is promoted, and the purification performance of these harmful components is improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining an engine exhaust gas purification apparatus according to an embodiment of the first invention, and FIG. 1 (A) is a longitudinal sectional view of an essential part, FIG.
FIG. 1B is a sectional view taken along line BB of FIG. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a vertical sectional view of an engine equipped with the exhaust emission control device of FIG.

As shown in FIG. 3, a lower connecting pipe 27, an exhaust gas purifier 2, an upper connecting pipe 28, and a muffler 16 are sequentially connected to the exhaust manifold 15 of the vertical diesel engine E,
The exhaust path 1 is configured. As shown in FIG. 1, the exhaust purification device 2 contains a purification filter 3. The purification filter 3 is a ceramic filter having a honeycomb structure, and is provided with a plurality of exhaust passages 18 therein, and alternately closes a lower end portion 19 and an upper end portion 20 of the exhaust passages 18. When passing through the porous partition wall 21, the surface of the porous partition wall 21 captures particulates in the exhaust gas to purify the exhaust gas.

The exhaust purifier 2 has the following structure in order to reduce the clogging of the purification filter 3 due to the trapped particulates. A swirl guide portion 5 is provided in the exhaust gas inlet 4 provided at the lower end side of the exhaust gas purifier 2. As shown in FIG. 1B, the swirl guide portion 5 is formed by cutting and raising a swirl guide blade 30 from a disc 29 that crosses the exhaust gas inlet 4. As shown in FIG. 1 (A),
An exhaust gas swirl chamber 6 is provided between the swirl guide unit 5 and the purification filter 3. Along the inner peripheral surface 7 of the exhaust swirl chamber 6, the electric heating section 8
Is provided. The heating section 8 is composed of a heating wire that is wound along the inner circumference of the exhaust gas swirl chamber 6 in a spiral shape. This heating wire is, as shown in FIG. 2, a non-conductive support portion 22,
The exhaust swirl chamber 6 is attached so as to be slightly floating from the inner peripheral surface 7.

The function of the exhaust purification system of the above embodiment is as follows. As shown in FIG. 1 (A), the exhaust gas 13 introduced from the exhaust gas introduction port 4 of the exhaust gas purifier 2 becomes a swirl flow in the swirl guide portion 5 and swirls in the exhaust gas swirl chamber 6. In the swirling exhaust gas 13, particulates having a larger specific gravity than the gas component are pushed out due to the difference in centrifugal force, are collected near the inner peripheral surface 7 of the exhaust gas swirling chamber 6, and are incinerated in the electric heating section 8. In this way, since the particulates in the exhaust gas are incinerated before reaching the purification filter 3, clogging of the purification filter 3 is reduced.

FIG. 4 is a view for explaining an exhaust emission control system for an engine according to an embodiment of the second invention, FIG. 4 (A) is a longitudinal sectional view,
FIG. 4B is a sectional view taken along the line BB of FIG. In the exhaust gas purifier 2 of this embodiment, the following structure is adopted in order to reduce the clogging of the purification filter 3 due to the trapped particulates.

An exhaust throttle chamber 10 having an air jet 9 is provided between the exhaust introduction port 4 provided at one end of the exhaust purifier 2 and the purification filter 3. A plurality of air ejection parts 9 are formed in the funnel-shaped wall 23 led out from the exhaust gas introduction port 4.
The wall 23 is surrounded by an air chamber 24, and the air chamber 24 has a ventilation pipe 25.
Compressed air is supplied from the compressor 26 via the. The air ejection portion 9 is the air 1 ejected from here.
As shown in FIG. 4 (B), 1 is orientated in a partial spiral shape so that 1 swirls along the inner peripheral surface 12 of the exhaust throttle chamber 10,
As shown in FIG. 4A, the inner peripheral surface 12 of the exhaust throttle chamber 10 is
The exhaust air 13 passing through the exhaust throttle chamber 10 is throttled to the central portion of the exhaust throttle chamber 10 by the wind pressure of the air 11 that swirls along. An electric heating part 1 is provided at the center of the exhaust throttle chamber 10.
4 are arranged.

The function of the exhaust emission control device of the above embodiment is as follows. Exhaust gas 1 passing through the exhaust throttle chamber 10 by the wind pressure of the air 11 that swirls along the inner peripheral surface 12 of the exhaust throttle chamber 10.
3 is concentrated in the center of the exhaust throttle chamber 10. Therefore, the particulates contained in the exhaust gas 13 are also contained in the exhaust throttle chamber 10.
It gathers in the central part of and is incinerated in the electric heating part 14. In this way, since the particulates in the exhaust gas are incinerated before reaching the purification filter 3, clogging of the purification filter 3 is reduced. Moreover, the air injection unit 12 is attached to the exhaust 13.
Since air is supplied abundantly from the CO, HC and CO in the exhaust
Oxidation such as is promoted.

The contents of each embodiment of the present invention are as described above, but the present invention is not limited to these embodiments. For example, although a ceramic filter having a honeycomb structure is used as the purification filter 3 in each of the embodiments, another filter such as a mesh filter may be used instead.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an engine exhaust gas purification apparatus according to an embodiment of the first invention, FIG. 1 (A) is a vertical cross-sectional view, and FIG. 1 (B).
FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a vertical cross-sectional view of an engine including the exhaust emission control device of FIG.

FIG. 4 is a diagram illustrating an exhaust emission control device for an engine according to an embodiment of the second invention, FIG. 4 (A) is a vertical cross-sectional view, and FIG. 4 (B).
FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a vertical cross-sectional view of an engine exhaust emission control device according to a conventional technique.

[Explanation of symbols]

1 ... Exhaust path, 2 ... Exhaust gas purifier, 3 ... Purification filter, 4
... Exhaust gas inlet, 5 ... Swirling guide, 6 ... Exhaust swirl chamber, 7 ...
6 inner peripheral surface, 8 ... electric heating portion, 9 ... air ejection portion, 10 ... exhaust throttle chamber, 11 ... air, 12 ... inner peripheral surface of 10, 13 ... exhaust gas, 14 ... electric heating portion.

Claims (2)

[Claims] 1. A cylindrical exhaust purifier (2) is provided in an exhaust path (1) of an engine, and the exhaust purifier (2) is provided with a purifying filter.
In an exhaust emission control device for an engine, which is configured to accommodate (3), a swirl guide section (5) is provided at an exhaust introduction port (4) provided at one end of the exhaust gas purifier (2), and the swirl guide is provided. Division (5)
An exhaust gas swirl chamber (6) is provided between the exhaust gas and the purification filter (3), and an electric heating part (8) is provided along the inner peripheral surface (7) of the exhaust gas swirl chamber (6). Engine exhaust purification device. 2. A cylindrical exhaust purifier (2) is provided in an exhaust path (1) of an engine, and the exhaust purifier (2) is provided with a purifying filter.
In an exhaust gas purification device for an engine, which is configured to accommodate (3), an air ejection part (4) is provided between an exhaust gas introduction port (4) provided at one end of the exhaust gas purification device (2) and a purification filter (3). The exhaust throttle chamber (10) provided with 9) is provided, and the air ejected from the air ejection part (9)
The air ejection part (9) is oriented so that the (11) swirls along the inner peripheral surface (12) of the exhaust throttle chamber (10),
The wind pressure of the air (11) swirling along the inner peripheral surface (12) of (10) causes the exhaust (13) passing through the exhaust throttle chamber (10) to be throttled to the center of the exhaust throttle chamber (10). And an electric heating section (14) arranged at the center of the exhaust throttle chamber (10).