JPH0551764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention aims to reduce the amount of soot emitted into the atmosphere by collecting particulate matter (hereinafter referred to as soot) emitted from, for example, diesel engines. This invention relates to an exhaust gas purifying burner that performs regeneration by burning the soot.

BACKGROUND ART In recent years, soot emitted from diesel engines has been regulated. In order to remove this soot, there is a method of installing a heat-resistant filter in the middle of the exhaust pipe. The feature of this method is that after a certain amount of soot has accumulated, it is incinerated and the filter is restored to its original state. Some devices that perform this regeneration include a burner installed upstream of the filter, which uses combustion heat to raise the temperature of the exhaust gas to the ignition temperature of soot and incinerate it. Burners used in this device include propane gas burners, light oil vaporizing burners, light oil atomizing burners, and the like. Propane gas burners must be equipped with a gas cylinder in addition to the light oil that is used as fuel for diesel engines. Additionally, light oil vaporizing burners are slow to start up and are not suitable for this purpose. As one of the light oil atomization burners,
A combustion section consisting of a fuel atomization nozzle, an air supply path, and a spark plug, a combustion chamber in front of it, and a valve at the outlet of the combustion chamber to flow high-temperature combustion gas to a filter during regeneration. Yes (Unexamined Japanese Patent Publication No. 61-11415)
Publication No.).

Problems to be Solved by the Invention However, although the above conventional example has sufficient combustion start-up, when trying to obtain high-temperature combustion gas containing sufficient oxygen to incinerate soot, excessive amounts of gas are generated in the combustion part. This resulted in the supply of air, which made combustion unstable. Additionally, the combustion chamber was heated with high-temperature gas, releasing valuable heat to the outside and wasting fuel.

Accordingly, the present invention is intended to enable soot to be easily incinerated with a single burner without emitting unpurified exhaust gas during regeneration, without destroying the filter due to thermal stress.

Means for solving the problem A cylindrical combustion chamber with a narrowed inner diameter at both ends, a combustion air port opening into the combustion chamber at one end of the combustion chamber,
A fuel atomizing nozzle placed at the center of the combustion air outlet facing toward the combustion chamber, a flame stabilizer plate provided at the tip of the combustion air outlet on the combustion chamber side, and the outer periphery of the flame stabilizer plate and the combustion chamber. It consists of an additional air outlet disposed between the end inlet and the combustion air amount and the addition air amount to be independently controlled.

Effect With the above configuration, the added air does not have a negative effect on combustion, so combustion is stabilized, and high-temperature combustion gas containing sufficient oxygen to incinerate soot is obtained, resulting in less soot. can be easily incinerated;
Filter regeneration is performed smoothly.

Embodiment An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view of an exhaust gas purifying burner. 1 is a burner body, and a fuel atomizing nozzle 2
is mounted in the center. Fuel atomization nozzle 2
has an atomizing air supply port 3 and a fuel supply port 4, which are connected to an air pump (not shown) and an oil pump (not shown), respectively. The burner body 1 has a ring-shaped combustion air inlet 6 coaxial with the fuel atomizing nozzle 2 and communicating with a combustion air supply port 5. Further, a funnel-shaped flame stabilizing plate 7 is arranged from the combustion air inlet 6 to the front of the fuel atomizing nozzle 2. The open part of the flame stabilizer plate 7 has a combustion air port 8 that blows out the combustion air introduced from the combustion air introduction port 6.
and a swirl vane 9 are provided. In addition, a hole is made in the middle of the throat of the flame stabilizer plate 7, and the fuel atomization nozzle 2
The igniter 10 penetrates to the vicinity of the burner body 1.
is fixed. This igniter 10 is connected to a high voltage transformer (not shown). Reference numeral 11 denotes a combustion chamber, which has a double structure of an outer cylinder 12 and an inner cylinder 13, and an air addition passage 14 is formed between the outer cylinder 12 and the inner cylinder 13. An air addition port 15 is provided on the outer periphery of the flame stabilizer plate 7 and communicates with the air addition passage 14 . Combustion chamber 1
The other end facing the combustion part 1 is narrowed to form a throat. Therefore, the additional air is removed from the combustion chamber wall to avoid waste of preheated fuel. Also, since it has a double structure, it also contributes to isolation from the outside world.

FIG. 2 shows an embodiment of a diesel exhaust gas purification device using the burner of the present invention. The diesel exhaust gas purification device is used with connection ports 16 and 17 installed in the middle of the exhaust pipe of a diesel engine. The throat of the combustion chamber 11 is connected to a four-way valve 18, and by the operation of an elliptical vane 19, two filters 20a, which are housed in a case via a cushioning material, are connected.
20b.

Next, the operation in this embodiment will be explained. First, we will explain the operation of a normal diesel engine. The engine was operated at a rotation speed of 1400 rpm and a torque of 122 Kg・m. In this case, in the four-way valve 18, the elliptical minor axis of the elliptical vane 19 and the line connecting the two opposing outlets are in the same direction, that is, the four-way valve 18 is in a neutral position, and the four-way valve 18 is in the neutral position. All openings connected to the valve 18 are in communication. At this time, the exhaust gas from the engine passes through the four-way valve 18 and passes through two filters 20.
a, 20b. Here, the soot contained in the exhaust gas is deposited on the filters 20a and 20b, and the exhaust gas becomes clean gas and is discharged into the atmosphere from the exhaust pipe.

Next, a case will be described in which soot is sufficiently deposited on the filters 20a and 20b to perform regeneration. First, when the elliptical vane 19 is rotated 90 degrees from the neutral position, the combustion chamber 11 and the filter 20a communicate with each other, and the other filter 20b communicates with the connection port 16 with the exhaust pipe. Then, a high voltage is applied to the igniter 10 to cause spark discharge at the tip, and then fuel and atomizing air are supplied to the atomizing nozzle 2, whereupon the fuel is atomized and ejected toward the combustion chamber 11. Combustion air supplied at the same time is blown out from the combustion air port 8, passes through the swirling vanes 9, becomes a swirling flow, and mixes with the atomized fuel spray. At this time, the fuel atomization is ignited by the spark at the ignition point 10, forming a flame. The flame is stably held by the flame stabilizing plate 7 and the flame is kept in the combustion chamber 11.
A good combustion condition is achieved within the combustion chamber. The additive air passes through the additive air passage 14 and is blown out from the additive air port 15 on the outer periphery of the flame stabilizer plate 7, and is mainly used in the combustion chamber 1.
A four-way valve 18 with the inner surface of 1 surrounded by flame.
leading to. Then, the combustion gas and the additive air mix well in the four-way valve 18, becoming a high-temperature gas with a high oxygen concentration, which reaches the filter 20a. The temperature of this high-temperature gas was maintained at approximately 600°C by controlling the combustion amount of the burner. The temperature can be controlled by other methods such as changing the amount of air added, and is not particularly limited. Here, the soot deposited on the filter 20a is heated, oxidized, and turned into combustion gas, which is released into the atmosphere through the exhaust pipe. While these operations are being performed, exhaust gas from the engine is passing through the other filter 20b, causing soot to accumulate there. This process takes a few minutes and the oval vane 19
When the filter is rotated 180 degrees, the flow paths of the high temperature gas from the burner and the exhaust gas from the engine are switched, the high temperature gas from the burner flows into the filter 20b, the soot is incinerated, and the filter 20b is regenerated. This process also takes a few minutes, and the oval vane 19 is rotated 90 degrees back to its original neutral position. This completes one regeneration and extinguishes the burner.

During this regeneration, the burner burned extremely stably despite fluctuations in the amount of combustion, and no problems such as misfires occurred. Furthermore, when the burner reached a steady state, it was possible to obtain high-temperature gas at the same temperature with an average smaller combustion amount than immediately after ignition. Furthermore, the temperature rise in the outer cylinder 12 due to combustion in the burner was within 50°C.

Effects of the Invention The present invention separates the additive air from the combustion air and blows them out under separate control, so that the additive air does not have an adverse effect on combustion, resulting in stable combustion and incineration of soot. As a result, the soot can be easily incinerated and the filter can be regenerated smoothly, so that the filter will not be destroyed by thermal stress.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a diesel exhaust gas purifying burner according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an example of a diesel exhaust gas purifying apparatus using the burner of the present invention. 2...Fuel atomization nozzle, 7...Flame stabilizer, 8...Combustion air port, 11...Combustion chamber, 15...Additional air port.

Claims (1)

[Claims] 1. An exhaust gas purification device having a filter for collecting particulates contained in exhaust gas, and a valve for switching an exhaust gas purifying burner and an exhaust gas flow path in front of the filter, which includes a combustion chamber and one end of the combustion chamber. a combustion air port opening into the combustion chamber; a fuel atomization nozzle placed toward the combustion chamber side at the center of the combustion air port; A flame stabilizer plate is provided, and an additional air port is arranged between the outer periphery of the flame stabilizer plate and the inner wall of the end portion of the combustion chamber, and the amount of combustion air and the amount of additional air are independently controlled. Features of exhaust gas purification burner.