JPH0511292Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a particulate filter in which a filter for collecting particulate is provided in the exhaust system of a diesel engine, and a burner for regeneration is provided on the upstream side of the filter. The present invention relates to a trap filter reproducing device.

[Prior Art] Recently, particulate matter emitted from diesel engines, or particulate matter, has attracted attention.
Investigations are underway into the effects on visibility deterioration and respiratory disorders. In order to reduce particulate matter, a particulate filter (hereinafter referred to as a filter) 4, which is held in a case (not shown) through a sealing material 3, is installed in the exhaust pipe 2 of the engine 1, as shown in FIG. A particulate trap filter regeneration device is known in which a burner 5 of light oil or the like is installed upstream of the filter 4 to reburn the particulate waste and regenerate the filter. One is known that is provided with a catalyst layer for purifying gas components (Japanese Utility Model Publication No. 171617/1983).

By the way, during regeneration, the high-temperature gas flow caused by a fire in the burner 5 tends to concentrate near the center of the filter 4, and the outer periphery tends to be cooled.
The temperature near the outer periphery of the filter does not reach the filter regeneration lower limit temperature TL, resulting in low regeneration efficiency.If the combustion temperature of the burner 5 is increased to deal with this, the temperature near the outer periphery of the burner 5 will decrease as shown in the characteristic B in Figure 3. is higher than the filter regeneration lower limit temperature TL, but the area near the center exceeds the filter melting temperature TU, and the filter 4
There is a problem that the burner 5 is melted and damaged, and the fuel consumption of the burner 5 increases.

For example, Japanese Utility Model Application Publication No. 59-43620 discloses a combustion chamber in which a combustion tube constituting a burner is provided separately from the exhaust passage, and first and second combustion rings are provided in the combustion tube. However, the purpose of such known techniques is to improve the formation of fire in the burner and to apply the fire uniformly to the filter member, and these rings are all located inside the combustion tube that constitutes the burner. These rings are therefore not able to homogenize the temperature distribution of the exhaust gas after the exhaust gas and combustion gas have exited.

Furthermore, Japanese Utility Model Application Publication No. 59-103816 discloses a technique in which a swirling flow is generated downstream of the burner, and the fire is spread by a ring to make the temperature distribution uniform on the upstream side of the filter. . However, in this technique, the exhaust gas flows in from a direction perpendicular to the direction of the fire, which causes the fire to be biased by the exhaust gas, which does not necessarily produce a uniform temperature distribution in front of the filter, and also causes the exhaust pipe to bend. , resulting in loss of flow and problems with installation on the vehicle.

[Problem to be Solved] Therefore, the purpose of the present invention is to provide a part filter that can be easily installed in a conventional exhaust pipe, minimizes the loss of exhaust gas flow, and can uniformize the temperature at the front of the filter. The present invention provides a trap filter reproducing device.

[Means for Solving the Problems] According to the present invention, a particulate trap filter regeneration system is provided in which a filter for collecting particulates is provided in the exhaust system of a diesel engine, and a regeneration burner is provided on the upstream side of the filter. In the apparatus, the outlet of the burner is open in the direction of the flow of exhaust gas in the exhaust pipe, and an orifice part whose central part is open is provided in the exhaust pipe between the burner and the filter on the downstream side of the burner. .

[Description of function and effect] Therefore, when regenerating the particulate trap filter, the high-temperature combustion gas from the burner is throttled together with the exhaust gas at the orifice section, and the exhaust pipe reaches its full inner diameter on the downstream side of the orifice section. It is expanded to. The turbulent flow at this time forces contact and mixing, and as a result, the temperature on the front surface of the filter is made uniform.
Therefore, it is possible to improve the regeneration efficiency by uniformly regenerating the filter to the vicinity of its outer periphery, and it is also possible to prevent the filter from melting and damage, and to minimize the amount of burner fuel required for regeneration.

In addition, the exhaust pipe can be constructed in a straight line as before, and there is only the throttling loss due to the orifice, so it can be applied to the conventional exhaust pipe, and it can be implemented without changing the layout of the conventional exhaust pipe.

[Preferred Embodiment] When carrying out the present invention, the orifice portion may be constructed of an orifice plate with a curved cross section, or
It may also be composed of a flat orifice plate. Furthermore, when implementing the present invention, it is preferable that the ratio between the diameter of the orifice portion and the inner diameter of the exhaust pipe is determined based on engine and other design conditions. In this way, the regeneration efficiency can be improved.

[Examples] Examples of the present invention will be described below with reference to the drawings.

In these drawings, parts corresponding to those in FIG. 4 are designated by the same reference numerals and redundant explanation will be omitted.

In FIGS. 1 and 2, an orifice portion A is provided between the burner 5 and the filter 4 of the exhaust pipe 2 by an orifice plate 6 that is open in the center. As shown in the figure, the outlet of the burner 5 faces the direction of the exhaust gas flow in the exhaust pipe 2. Although the cross-sectional shape of this orifice plate 6 is formed into a gentle curve, it is not limited to this.
It may be a flat plate cross section. Further, the ratio d/D between the diameter d and the inner diameter D of the exhaust pipe 2 is determined by engine and other design conditions.

Since the filter regeneration device according to the present invention is constructed as described above, the flow of exhaust gas is throttled at the orifice part A and expanded to the full inner diameter D of the exhaust pipe 2 on the downstream side of the orifice part A, and Forcibly mixed with high-temperature combustion gas. Therefore, the front temperature of the filter 4 is made uniform within the range between the filter regeneration lower limit temperature TL and the filter melting temperature TU, as shown by the characteristic D in FIG. As a result, it is possible to improve the regeneration efficiency by uniformly regenerating the filter 4 to the vicinity of its outer periphery, and it is also possible to prevent the filter 4 from melting and damage, and to minimize the amount of fuel required for the burner 5 for regeneration.

[Effects of the invention] As described above, the present invention provides the following excellent effects.

(a) The flow of exhaust gas is throttled at the orifice and expanded to the full inner diameter of the exhaust pipe on the downstream side of the orifice, and the high-temperature combustion gas from the burner and the exhaust gas are forced into contact and mixed by turbulence, so the filter The front temperature is equalized.

(b) Improve regeneration efficiency by uniformly regenerating near the outer periphery of the filter.

(c) It is possible to prevent the filter from melting and to minimize the amount of burner fuel required for regeneration.

(d) There is no need to change the layout of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the line I-I in Fig. 1, and Fig. 3 is a comparison of the temperature characteristics of the front surface of the filter of the present invention and the characteristics of a conventional device. 4 are side sectional views showing a conventional device. 1...engine, 2...exhaust pipe, 4...filter, 5...burner, 6...orifice plate.

Claims (1)

[Scope of utility model registration request] In a particulate trap filter regeneration device, a particulate trap filter regeneration device is provided with a filter for collecting particulate in the exhaust system of a diesel engine, and a regeneration burner is provided on the upstream side of the filter.
The outlet of the burner is open in the direction of the flow of exhaust gas in the exhaust pipe, and the exhaust pipe between the burner and the filter is provided with an orifice part whose center part is open on the downstream side of the burner. A part-collect trap filter regeneration device.