JPS59130554A - Exhaust gas purifying apparatus - Google Patents

Abstract

PURPOSE:To burn carbon dust efficiently by blowing air from the lower part into a dust collecting chamber through an air diffusing plate and heating by a heater while fluidizing the collected carbon dust in the dust collecting chamber. CONSTITUTION:An exhaust gas exhausted from an internal-combustion engine is sent into a cyclone dust collector 3, and the carbon dust or the like contained in the exhaust gas is separated and collected. The collected carbon dust is burnt in the collector 3 by means of a heater 4 for burning the carbon dust equipped in the collector 3. In this exhaust gas purifying apparatus, a porous air diffusing plate 9 permitting the passage of the air current is equipped at the bottom of a dust collecting chamber 32 provided with the dust burning means 4. The air is blown into the chamber 32 from the lower part through the diffusing plate 9, and the collected carbon dust is burnt by the heating with the heater 4 while fluidizing the dust in the chamber. In this way, the carbon dust can be burnt efficiently at a high burning rate.

Description

[Detailed Description of the Invention] This invention separates and collects dust containing carbon as a main component from exhaust gas discharged from an internal combustion engine such as an automobile engine, and then incinerates the dust. This relates to an exhaust gas purification device to be disposed of.

The exhaust gas of internal combustion engines, especially diesel engines, contains a large amount of soot mainly composed of carbon, which is also a factor in air pollution. For this reason, various types of devices have recently been developed that purify the exhaust gas by separating and collecting dust such as carbon from the exhaust gas. Such devices are generally mounted on cars and purify the exhaust gases of internal combustion engines before they are released into the atmosphere, but they are also used to purify exhaust gases from the internal combustion engines before they are released into the atmosphere. It is also used as a large-scale exhaust gas purification device to purify gas.

In addition, as a means for separating and collecting dust in the above exhaust gas purification equipment, a cyclone dust multiplier is often used, as it is robust and requires little maintenance. A method is also known in which carbon dust and the like are incinerated in a cyclone dust multiplier by heating with a heater.

As described above, this invention sends the exhaust gas discharged from the internal combustion engine to the cyclone dust multiplier, separates and collects carbon dust, etc., and then collects the collected carbon dust in the cyclone dust multiplier. This invention relates to an exhaust gas purification device that is incinerated indoors, and first, the conventional structure of this type of automobile tower-mounted exhaust gas purification device will be explained with reference to FIG.

In Figure 1, 1 is an internal combustion engine such as a diesel engine, 2 is an electrostatic precipitator or other type of dust condenser, 3 is a cyclone multiplier connected after the dust condenser 2, and 4 is a cyclone multiplier. This is a heater for burning carbon dust installed in the dust collection chamber of the dust collector 3. Note that the tunnel dust collector does not have an internal combustion engine as shown in the figure, but instead has a prower that sends air within the tunnel toward the cyclone dust multiplier 3, which is connected upstream of the dust condenser. Returning to Figure 1, with this configuration, the exhaust gas containing carbon particles discharged from the engine 1 enters the agglomerator, where the submicron carbon particles with a single particle size of about 0.2 μm are aggregated and coarsened. Cyclone dust multiplier 3
sent to. In the cyclone dust multiplier 3, as is well known, fine particles are centrifuged on the main airflow A that swirls and descends within the cyclone body 31, move downward along the inner wall of the cyclone body 31, and settle into the dust collection chamber 32. Accumulated.

On the other hand, the exhaust gas purified by separating the particulates rises as a reverse airflow B and is discharged into the atmosphere through the cyclone outlet pipe 33. On the other hand, the heater 4 surrounded by the filter 5 is provided at the bottom of the dust collection chamber 32 as described above, and is energized by the power source 7 via the switch 6 which is turned on depending on the operating state of the engine. Therefore, the carbon dust 8 collected in the dust collection chamber 32 and accumulated on the filter 5 is incinerated by heating by the heater 4.

On the other hand, the conditions for burning carbon dust 8 are as follows:
In addition to heating the heater, it is also important to supply sufficient oxygen to the combustion section. In this regard, in the method shown in FIG. 1, in which the carbon dust 8 collected and deposited on the heater at the bottom of the dust collection chamber is incinerated by heater heating, if the dust collection chamber 32 remains closed, the carbon dust A sufficient amount of oxygen cannot be supplied into the layer. In other words, cyclone dust multiplier 3
A part of the main air flow containing oxygen flowing through the dust collection chamber 32 flows through the dust collection holes, but if the dust collection chamber 32 is a closed space, this indoor air flow is reversed from the center of the dust collection chamber 32. The liquid then rises and flows out toward the outlet 33. For this reason, the supply of oxygen to the inside of the layer of carbon dust 8 near the heater 4 is performed only by diffusion within the carbon dust layer, and is therefore insufficient.As a result, the burning rate of carbon dust decreases, unburned etc. problem occurs.

As a countermeasure against this problem, for example, blowdown is performed by extracting a part of the indoor airflow from the bottom of the dust collection chamber 32 in FIG. Conventionally, methods have been proposed that ensure the supply of oxygen necessary for combustion. However, in the above-mentioned blowdown method, the bleed air flow passes through the filter 5 after flowing through the carbon dust layer.
First of all, not only is the heat lost by the wind a dog;
On the other hand, new problems arise, such as clogging of the filter 5, and ash generated by incineration of carbon dust directly depositing on the filter 5, insulating heater heat and reducing incineration performance. . In addition, in any of the conventional methods, it is necessary to install the heater 4 over the entire area of the dust collection chamber, which requires a large-capacity heater with high power consumption.

This invention was made in consideration of the above points, and its purpose is to eliminate the drawbacks of conventional devices, to efficiently incinerate separated and collected carbon dust with a small-capacity heater, and to provide a practical and easy-to-maintain device. The purpose of the present invention is to provide a comprehensive exhaust gas purification device.

According to the present invention, a porous air diffusion plate that allows gas to permeate is installed at the bottom of a carbon dust accumulation chamber in a cyclone dust collector equipped with carbon dust incineration means, and a porous air diffusion plate that allows gas to pass through the air This is achieved by blowing air into the dust accumulation chamber at a slower wind speed and incinerating the collected carbon dust by heating it with a heater instead of fluidizing it.

Embodiments of the present invention will be described in detail below based on the drawings.

First, in the embodiment shown in FIG. 2, an air diffusion plate 9 made of a porous material is installed at the bottom of the dust collection chamber 32, which is a carbon dust accumulation chamber, and a carbon dust combustion heater is installed at a position slightly above the air diffusion plate 9. 4 is installed. In addition, a space partitioned below the air diffusion plate 9 is defined as a plenum chamber 10,
A blow amplifier piping 12, one end of which is open to the atmosphere, is connected through a blower.

In such a configuration, during exhaust gas purification processing, the follower 1
1, and set the discharge air pressure appropriately to open the plenum chamber 1.
When outside air is blown into the dust collection chamber 32 through the air diffusion plate 9 in the direction of the arrow, the dust 8 that has been separated from the exhaust gas and deposited in the dust collection chamber is removed by the above-mentioned blown air. The particles of carbon dust 8 are fluidized by the inflowing air current, and the particles of carbon dust 8 individually move in a random floating motion within the layer as shown by the arrows in the figure.Here, if the heater 4 is energized and heated to about 800 degrees Celsius, The carbon dust 8 touches the heater 4 and burns and disappears almost instantly. In addition, the oxygen required for combustion is sufficiently supplied by the forced blast of outside air, resulting in high combustion efficiency and rapid incineration. ! Since the carbon dust 8 moves around the heater 4 due to fluidization, there is no need for the heater 4 to be spread over the entire area of the dust collection chamber. It is sufficient that the blow-up airflow is blown up from below,
There is no need to worry about clogging, which was a problem with the blowdown method, and therefore continuous operation for long periods of time is possible without the need for maintenance. Note that the amount of blow-up air flow blown into the dust collection chamber 32 is sufficient to be about 0.1% to 1.0% of the amount of exhaust gas treated by the cyclone dust collector, and has little effect on the cyclone dust collection efficiency. It will not cause any adverse effects. According to experiments conducted by the inventor, in a diesel engine with a displacement capacity of 2 mm, the amount of exhaust gas at a rotation speed of 200 rpm is approximately 2 m''/min, and a follow-up result was obtained by setting the blow-up air volume to 2737 m1n. Ta.

In addition, the blow-up piping 1 that serves as the outside air pushing ventilation path
By installing an air preheating heater 13 in the middle of the combustion chamber 2 and sending the blow-up air flow into the dust collection chamber 32 in a heated state, combustion can be promoted more efficiently. It is effective.

FIG. 3 shows an embodiment in which the arrangement of the heaters is changed compared to the embodiment shown in FIG. ing. The operation of incinerating the Naori-Bon dust 8 is performed in the same manner as in the embodiment shown in FIG.

Next, FIGS. 4 and 5 show still another embodiment.

In this embodiment, the cyclone dust collector 3 is used in a horizontal position for convenience when mounted on an automobile. Naori-
When collecting fine particles such as bond dust, there is almost no difference in dust collection efficiency even if the cyclone dust collector is used in a horizontal position. 1. A dust collecting chamber 14 as a dust collecting chamber is defined adjacent to the cylindrical dust collecting chamber 32, and a heater 4 serving as a carbon dust incineration means is installed at the bottom of the chamber and an air diffusion plate is installed as in FIG. It is installed together with 9. This dust collection chamber 14 is connected to the dust collection chamber 32 through a narrow dust collection slit 15 opened in the peripheral wall of the dust collection chamber 32.
The chamber is in communication with the chamber, and the shape of the chamber is such that the cross-section of the chamber at both the bottom and the top of the chamber is an inverted trapezoid with a wide slope at the top.

In this configuration, when purifying exhaust gas, the carbon dust that is centrifuged from the main airflow A of the cyclone dust collector 3 and collected in the dust collection chamber 32 has an extremely small bulk density, and the dust particles are Through the dust collection room 32
The dust particles flow into the dust collection slit 15 and move along the inner wall surface of the dust collection chamber 32 on the airflow C swirling inside the room, and in this process, the dust particles reach the dust collection slit 15, and due to the centrifugal force, the dust particles are 15 into the dust collection chamber 14, and is accumulated in this chamber. This operation continues during operation, so that the carbon dust collected in the dust collection chamber 32 is transferred from the dust collection chamber 32 to the tart collection chamber 14, which is another chamber, and is collected.

With this configuration, it is possible to reliably prevent the carbon dust 8 collected in the dust collection chamber 14 from being re-scattering or escaping by the airflow flowing out to the cyclone outlet 33 after swirling in the dust collection chamber 32. , a high carbon dust collection rate can be obtained. A heater 4 is placed at the bottom of the carbon dust 8 collected in the dust collection chamber 14. By disposing the air diffusion plate 9 and blowing up outside air in the direction of the arrow through the plenum chamber 10 while energizing the heater 4, the separated and collected accumulated carbon dust 8 is incinerated in the same manner as in the previous embodiments. can do. Moreover, according to the embodiment of FIG. 4, the swirling airflow C in the dust collection chamber 32
does not affect the internal space of the dust collection chamber 14,
There is no risk of the carbon dust re-scattering or escaping, and the atmosphere inside the dust collection chamber 14 is not disturbed by the swirling airflow C, so the fluidization of the collected carbon dust 8 due to the blow-up effect is stabilized, and the carbon Dust 8 can be incinerated more efficiently. Note that the blow-up airflow rises inside the dust collection chamber and enters the dust collection chamber 3 through the slit 15.
2 and then merges with the airflow C to the cyclone outlet 33
However, in this case, the blow amplifier airflow has a small wind basin and the wind speed is extremely low, so centrifugal force acts from the dust collection chamber 32 into the dust collection chamber 4. This does not impede the movement of incoming dust particles. Moreover, as mentioned earlier, the dust collection chamber 1
By configuring the cross-sectional shape of 4 as an inverted trapezoid, the force of the wind escaping from the dust collection chamber 14 toward the dust collection chamber 32 is further weakened, and the influence on the centrifugal movement of the dust particles is further increased. This is advantageous because it is smaller.

In the embodiment shown in FIG. 4, the heater 4 can also be arranged as shown in FIG. 2, and in the embodiments shown in FIGS. Outside air is forced in and blown out.

As described above, the present invention blows up outside air from below through a porous air diffusion plate into the carbon dust collection chamber of a cyclone dust collector equipped with carbon dust incineration means to generate a fluid state of carbon dust. Therefore, the carbon dust is incinerated by heating with a heater. Therefore, the contact between the carbon dust and the heater and the supply of oxygen necessary for combustion are sufficiently performed, and the carbon dust can be incinerated efficiently and at a high combustion rate. Moreover, the heater can be small and small in capacity, which consumes less power, and there is no need to worry about problems such as filter clogging, so it can be used continuously for a long time without maintenance. It is possible to provide an exhaust gas purification device that is highly effective in practical use, such as for purifying the exhaust gas of an automobile tower-mounted internal combustion engine or for purifying the air in a tunnel as described above.

[Brief explanation of the drawing]

Figure 1 is a system diagram of the entire conventional exhaust gas purification system.
2, 3, and 4 are schematic configuration diagrams showing the main parts of different embodiments of the present invention, and FIG. 5 is an overall diagram of the cyclone dust collector of the embodiment shown in FIG. 4. be. 1... Internal combustion engine, 3... Cyclone dust collector, 32
... Dust collection chamber, 4 ... Heater for carbon dust incineration, 8 ... Carbon dust, 9 ... Air diffusion plate, 10
... Plenum room, 11... Blower, Work 2... Blow-up piping, 13... Air preheating heater, 14...
Dust collection chamber, 15...Dust collection slit.

Claims (1)

[Claims] 1) Exhaust gas discharged from an internal combustion engine is sent into a cyclone dust collector to separate and collect carbon dust, etc. contained in the exhaust gas, and the exhaust gas is sent to the cyclone dust collector. In an exhaust gas purification device in which collected carbon dust is incinerated in a cyclone dust collector by a carbon dust combustion heater provided with the device, the bottom of the dust accumulation chamber provided with the carbon dust incineration means is provided with a porous structure that allows airflow to pass through. In addition to arranging an air diffusion plate, air is blown into the dust accumulation chamber from below through the air diffusion plate, and the collected carbon dust is incinerated by heating without being fluidized in the room. Exhaust gas purification device. 2. The exhaust gas purification device according to claim 1, characterized in that the carbon female combustion heater is disposed above the air diffusion plate at a location within the layer of accumulated carbon waste. Gas purification equipment. 3) The exhaust gas purification device according to claim 1, wherein a carbon dust combustion heater is attached to a part of the air diffusion plate. 4) In the exhaust gas purification device according to any one of claims 1 to 3, outside air is forced and supplied through a blower toward a plenum chamber defined below the air diffusion plate. An exhaust gas purification device characterized by: 5) In the exhaust gas purification device according to any one of claims 1 to 4, an air preheating heater is provided in the middle of the outside air forcing ventilation path, and the outside air is preheated and heated to remove dust. An exhaust gas purification device characterized in that the exhaust gas is blown into a collection chamber.