JPH01193011A - Processing device for dust containing gas - Google Patents

Abstract

PURPOSE:To promote backwashing effect by setting a suction means to a receptor of fine particles are eliminated during the backwashing process in the case of a filter for catching fine particles contained in the exhaust gas from a diesel engine to be backwashed by compressed air injected from a nozzle. CONSTITUTION:Exhaust gas introduced from a introduction pipe 37 is led to dust containing gas channels 34 which penetrates from upward to downward through a filter 33 housed in a casing 31. Fine particles are eliminated when the gas is led through filter walls made of a gas ventilating porous material, and cleaned gas is led through clean gas channels 35 to be exhausted from a leading out pipe 38. In addition, fine particles adhering to the inside walls of dust containing gas channels 34 are peeled off by injection of compressed air for a short period from a nozzle 40 after lapse of a preset time, in a backwashing process and recovered in a receptor 41, then incinerated by the heat of an electric heater 46. In such a processing device, a suction fan 48 is attached to an auxiliary sub introduction pipe 45 of the receptor 41, and is controlled to synchronously operate with the operation of nozzle 40.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a dust-containing gas processing device suitable for capturing or removing particulates contained in, for example, exhaust gas from a diesel engine.

[Prior art and its problems] Exhaust gas from diesel engines contains fine particles, mainly carbon, at a considerable concentration, causing pollution. Therefore, various devices have been proposed that use a filter body to collect or remove such particulates from the day cell exhaust gas.

JP-A-56-124417 discloses a cross-flow type filter 33 shown in FIG. This filter 3
3 has a rectangular parallelepiped outer shape as a whole, and includes a plurality of mutually parallel rectangular plate bodies 21 (eight in FIG. 6) and ribs 2.
2.23. Plate body 21 and ribs 22.23
Both are made of a porous ceramic air-permeable solid that has a filter function. A plurality of ribs 22 extend parallel to one side of the plate-like bodies 21 at predetermined intervals between the adjacent plate-like bodies 21,21. Each rib 22 is in integral contact with the plate-like bodies 21 on both sides, thereby forming a plurality of dust-containing gas passages 34 that are open at both ends. Plate body 2
1 is provided with such a rib 22, whereas the other side of the same plate-like member 2I is provided with a rib 23 extending in a direction perpendicular to the rib 22. The rib 23 is essentially the same as the rib 22 except for the difference in the direction of travel.3 Thus, both ends are open and the direction of travel is the dust-containing gas passage 34.
A plurality of clean gas passages 35 are formed perpendicular to the .

In this filter 33, one of the two end faces through which the dust-containing gas passage 34 opens is closed, and the day cell exhaust gas is passed through the other end face. Or dust-containing gas passage 34
The day cell exhaust gas is simultaneously passed inward from both open end faces of the cylinder. The plate-like body 21 acts as a filter wall, and the fine particles pass through the plate-like body 21.
The clean exhaust gas collected on the side of the dust-containing gas passage 34 and from which particulates have been removed passes through the plate-like body 21 and flows out of the system via the clean gas passage 35. The collected particulates are burned and removed by heating the filter 33 to the combustion start temperature of carbonaceous particulates at appropriate time intervals.
Filter 33 is regenerated.

However, in such prior art, the combustion removal of particulates repeatedly heats the filter to high temperatures, sintering the filter, changing the initial pore size and bore distribution, and causing changes in collection efficiency and pressure drop over time. As a result, it is difficult to maintain stable performance, and many of them result in performance deterioration over time. Above all, the plate-shaped body 2 is removed by high-temperature combustion.
2 was eroded and it often happened that it became impossible to collect any fine particles.

In addition to the carbonaceous fine particles, a negligible amount (for example, 1 to 5% of the total weight of the fine particles) of nonflammable components is present in the day cell exhaust gas, and these are also collected by the filter. Alternatively, nonflammable solids produced by SOx and NOx in diesel exhaust gas reacting with the constituent materials of the gas pipe and the filter are deposited on the filter. These non-flammable solids are not removed by combustion and accumulate, reducing the performance of the filter.

In order to solve the above-mentioned problems, the present applicant has already proposed a particle processing device as shown in FIG. 7 (Japanese Patent Application No. 232360/1982).

That is, a rectangular parallelepiped-shaped filter 33 is housed inside a casing 31 that has openings 11 at the top, bottom, and one side, with a required seal member 32 interposed therebetween. The filter 33 is essentially the same as the filter 33 in FIG.
4 (indicated by a solid line arrow in the figure) and a clean gas passage 35 (indicated by a broken line arrow in the figure), which is closed at one end and opens laterally at the other end, by a filter wall made of a breathable porous material. It has been made.

At the top of the casing 31 is an introduction pipe 3 for diesel exhaust gas.
7, and a clean gas outlet pipe 38 is connected to the casing 31 on the side where the clean gas passage 35 opens. The outlet pipe 38 includes a throat 39 having a reduced diameter, and its upstream and downstream portions are gradually expanded in diameter.

Immediately downstream of the throat 39, there is provided a nozzle 4o for pressurized gas injection that opens toward the upstream side.

A particulate bag section 41 provided at the lower part of the casing 31 has an auxiliary filter 4 equipped with a tray 42 and an electric heater 46.
3. Ash removal chamber 44, which is equipped with a lid 47 that can be opened and closed and is normally closed. It has an auxiliary outlet pipe 45.

The bottom of the tray 42 is hollowed out and an auxiliary filter 43 is inserted therein, and the tray 42 and the auxiliary filter 43 collectively surround the lower opening ends of all the dust-containing gas passages 34. . The ash removal port 44 is connected to the tray 42
An auxiliary outlet pipe 45 is opened at the bottom of the auxiliary filter 43 and is located outside the auxiliary filter 43 . The auxiliary filter 43 is made of a breathable porous solid, and its ventilation resistance is approximately 20% or less, particularly 0.5 to 0.5% of the amount of exhaust gas introduced from the introduction pipe 37.
It is selected so that about 5% of the water passes through this auxiliary filter 43 and the rest passes through the filter 33 and flows out into the outlet pipe 38.

Diesel exhaust gas is introduced into the dust-containing gas passage 34 of the filter 33 through the introduction pipe 37 from its upstream opening end. Most of the exhaust gas passes through the filter wall and flows out to the outlet pipe 3B via the clean gas passage 35, but the fine particles in the exhaust gas cannot pass through the filter wall and accumulate on the inner surface of the dust-containing gas passage 34. A part of the particles may flow out through the lower open end of the dust-containing gas passage 34 into the particle sac 41. Part of the exhaust gas is part 4! The exhaust gas passes through the auxiliary filter 43 and is guided to the auxiliary outlet pipe 45. However, even here, the particulates in the exhaust gas cannot pass through the auxiliary filter 43 and are deposited on the inner surface of the auxiliary filter 43.

After continuing this dust collection operation for an appropriate time, a short-time backwashing operation is performed. In the backwashing operation, pressurized gas, particularly pressurized air, is injected from the nozzle 40 for a period of, for example, about 0.1 to 1 second. . The injected gas attracts gas around the nozzle 40,
Gas several times the initial pressurized gas amount flows into the clean gas passage 35 as a pulse flow. Dust-containing gas passage 34 passes through the filter wall
flows to. At that time, the particulates that had adhered and accumulated on the inner surface of the dust-containing gas passage 34 peel off, and some of them fall off the dust-containing gas passage 34.
However, the particles fall and the particulate sac enters part 41.

In this way, particulates trapped on the inner surface of the dust-containing gas passage 34 during the dust collection operation are transferred to the inner surface of the auxiliary filter 43 during the backwashing operation, and the filter function of the filter 33 is also regenerated. The particulates on the auxiliary filter 43 are burned and removed by heating by the electric heater 46.

When non-flammable particles and ash accumulate in the part 4I of the particulate bag, especially in the auxiliary filter 43, due to relatively long-term use, the lid 47 may be opened to allow the particulates and ash to fall naturally, or an appropriate scraping mechanism may be used. It can also be forcibly ejected.

However, in the above-mentioned particulate processing device, during backwashing operation, the backwash air flow passes from the clean gas passage 35 through the filter wall to the dust-containing gas passage 3.
4, and the particulate sac also flows into section 41.

Particulates that have fallen from the dust-containing gas passage 34 are deposited in the part 41 of the particulate bag, and the deposited particulates are scattered by the backwashing airflow, and some of them return into the dust-containing gas passage 35 . In addition, some of the particles that have fallen off from the dust-containing gas passage 34 due to the backwash air flow are located not in the part 41 but in the inlet pipe 3.
It flows back into 7. Therefore, when the backwashing operation is completed and the dust collection operation returns, the particles scattered from the part 41 and the particles flowing back into the introduction pipe 37 are carried by the flow of exhaust gas and returned to the dust-containing gas passage 34. There was a problem in that it adhered to the inner wall and the backwashing effect was not sufficiently achieved.

"Objective of the Invention" An object of the present invention is to provide a dust-containing gas processing device that allows backwashing airflow to collect particulates at a predetermined location without scattering them, thereby increasing the backwashing effect. It is in.

"Structure of the Invention" The dust-containing gas processing apparatus of the present invention is as follows. a filter having a dust-containing gas passage and a clean gas passage separated by a filter wall; an introduction pipe for introducing dust-containing gas into the dust-containing gas passage; A lead-out pipe that leads out the clean gas flowing into the gas passage, a backwashing means that intermittently generates a gas flow that flows from the clean gas passage through the filter wall to the dust-containing gas passage, and the dust-containing gas passage. The particulate bag is arranged to receive particulates from the part, and the particulate receiving part is connected to an auxiliary outlet pipe via an auxiliary filter that captures the particulates and allows gas to pass through. It is characterized in that the outlet pipe is provided with a suction means that operates in synchronization with the backwashing means.

"Operation" Therefore, in the present invention, when backwashing is performed by the backwashing means, the gas inside the particulate sac is suctioned from the auxiliary outlet pipe by the suction means in synchronization with the backwashing. The backwash airflow flows from the clean gas passage of the filter through the filter wall into the dust-containing gas passage, and peels off particulates attached to the inner wall of the dust-containing gas passage. These particles are carried by the airflow sucked in from the auxiliary outlet tube, and most of them enter the particle sac.
The particulate sacs are captured by an auxiliary filter. Because of the airflow sucked from the auxiliary outlet pipe, the number of particles flowing back from the dust-containing gas passage to the inlet pipe is extremely reduced. Further, due to the airflow, particles accumulated on the auxiliary filter are also prevented from being scattered by the backwash airflow. In this way, most of the particles that have fallen off from the inner wall of the dust-containing gas passage due to backwashing are collected on the auxiliary filter in the particulate bag, and are prevented from being reattached to the inner wall of the dust-containing gas passage. The effect can be further enhanced.

"Embodiments of the Invention" Examples of the present invention will be described below with reference to FIGS. 1 to 4. In each figure, parts that are substantially the same as those of the apparatus in FIG. , to simplify the explanation.

The dust-containing gas treatment apparatus according to the first embodiment of the present invention shown in FIG. 1 has substantially the same structure as the apparatus shown in FIG. The only difference is that a suction fan 48 is connected. This suction fan 48 operates in synchronization with the operation of the nozzle 40.

Therefore, in the backwash operation using this dust-containing gas treatment device, pressurized gas is ejected from the nozzle 40, and the gas around the nozzle 40 is attracted by the esector effect at the throat 39, reducing the initial amount of pressurized gas. Several times the amount of gas is made to flow into the clean gas passage 35 as a pulse flow. This backwash air flow passes through the filter wall of the filter 33 and flows into the dust-containing gas passage 34, and peels off the particulates adhering to the inner wall of the dust-containing gas passage 34.

On the other hand, in synchronization with the operation of the nozzle 40, the suction fan 48
The gas is sucked through the auxiliary outlet pipe 45.

Therefore, the particulate bag passes through the part 41 from the dust-containing gas passage 34, further passes through the auxiliary filter 43, and then passes through the auxiliary outlet pipe 45.
An airflow is generated. Due to this airflow, most of the particulates that have fallen off from the inner wall of the dust-containing gas passage 34 are drawn into the particulate bag 41, captured by the auxiliary filter 43, and deposited thereon. Therefore, of the particulates peeled off from the inner wall of the dust-containing gas passage 34 by the backwash airflow, the amount of particulates flowing back into the introduction pipe 37 is extremely small. Also, even if the backwash airflow flows into the particulate bag section 41, the auxiliary filter 4
Since the fine particles deposited on the surface 3 are suctioned by the suction fan 48, they are prevented from scattering.

In this way, most of the particulates that have fallen off from the dust-containing gas passage 34 due to backwashing are collected on the auxiliary filter 43, increasing the backwashing effect. The particulates collected in the auxiliary filter 43 can be burned and removed by the electric heater 46, and the ash remaining after the combustion can be taken out from the ash removal port 44 by opening the lid 47.

In the dust-containing gas processing apparatus according to the second embodiment of the present invention shown in FIG. 2, an auxiliary outlet pipe 45 is connected to the throat 39 of the outlet pipe 38 to constitute a suction means. Other points are similar to the embodiment shown in FIG.

The backwashing operation in this device is performed using the nozzle 40 as described above.
This is done by ejecting pressurized gas from the

As mentioned above, when pressurized gas is ejected from the nozzle 40,
Gas around the nozzle 40 is attracted by the esector effect of the throat 39. At this time, the gas in the auxiliary outlet pipe 45 connected to the throat 39 is also attracted, and due to this suction force, the particulate bag passes through the part 41 from the dust-containing gas passage 34, further passes through the auxiliary filter 43, and enters the auxiliary outlet pipe 45. An airflow is generated. This airflow provides the same backwashing effect as in the above embodiment.

In the dust-containing gas treatment apparatus according to the third embodiment of the present invention shown in FIG. 3, four valves are provided in the outlet pipe 3B. Auxiliary outlet pipe 4
5 is connected to the outlet pipe 38 upstream of the valve 49 in the flow of clean gas. A throat 50 having a reduced diameter is provided in the middle of the auxiliary outlet pipe 45. In the auxiliary lead-out pipe 45 on the upstream side of the throat 50, there is a lead-out pipe 3.
A nozzle 40 for injecting pressurized gas is arranged to open in the flow direction to 8.

When the nozzle 40 blows out pressurized gas, the valve 49 is closed in synchronization with this.

In this device, during dust collection operation, the valve 49 is open, and the dust-containing gas is introduced from the introduction pipe 37 into the dust-containing gas passage 34 of the filter 33, passes through the filter wall of the filter 33, and becomes clean gas. The gas is discharged from the outlet pipe 38 through the clean gas passage 35. Part of the dust-containing gas enters the particulate bag 41, passes through the auxiliary filter 43, and becomes clean gas.
The gas passes through the auxiliary outlet pipe 45 and is further combined with the clean gas in the outlet pipe 38 to be discharged.

The backwashing operation in this device is performed by jetting pressurized gas from the nozzle 40 and closing the valve 49 in synchronization with this. When the pressurized gas is ejected from the nozzle 40, the gas around the nozzle 40 is attracted by the ejector effect of the throat 50, and several times the initial amount of pressurized gas is discharged from the auxiliary outlet pipe 45 as a pulse flow. 38, the valve 49 is closed in the outlet pipe 38, and the airflow caused by the nozzle 40 flows back through the outlet pipe 3B and into the clean gas passage 35 of the filter 33, acting as a backwash airflow. On the other hand, the gas in the auxiliary outlet pipe 45 flows into the outlet pipe 38 due to the pressurized gas from the nozzle 40, so that the particulate bag passes through the part 4I from the dust-containing gas passage 34, and further passes through the auxiliary filter 43. An airflow that escapes to the auxiliary outlet pipe 45 is generated. This airflow provides the same backwashing effect as in the embodiment shown in FIG.

In the dust-containing gas treatment apparatus of the fourth embodiment of the present invention shown in FIG. 4, the filter is as shown in FIG.

A filter 10 is used.

This filter IO is basically a columnar body (a so-called ceramic honeycomb body) which is divided by a filter wall 11 made of breathable porous ceramics and has a large number of parallel gas passages adjacent to each other with the filter wall 11 as a boundary. On one end face of the columnar body, the end faces of each gas passage are alternately blocked in a checkerboard pattern as shown by hatching in FIG. The gas passages that were closed are opened, and the gas passages that were open at the one end surface are closed. Thus filter wall 1
A large number of dust-containing gas passages 34 and a large number of clean gas passages 35 are formed.

The filter 10 is housed inside a casing 31 having openings on the upper and lower sides, with a necessary seal member 32 interposed therebetween. The filter 10 is arranged such that the dust-containing gas passage 34 and the clean gas passage 35 extend in the vertical direction. Directly below the casing 31, there is a particulate bag in the part 4.
1 is formed, and the casing 31 and the particulate bag are part 4.
1, a dust-containing gas introduction pipe 37 is connected from the side and opened.

The bottom of part 41 of the particulate bag is open, and an auxiliary filter 43 is fitted therein, and an electric heater 46 is attached to the auxiliary filter 43. In addition, the particulate sac is part 41
An ash removal pipe 44 having a lid 47 is formed on the lower side wall of the ash pipe. One end of an auxiliary outlet pipe 45 is connected to the bottom opening of the particulate bag section 41 via the auxiliary filter 43 .

Casing 3! A clean gas outlet pipe 38 is provided at the upper opening of the
is connected, and the outlet pipe 38 is provided with a throat 39 having a reduced diameter. In the outlet pipe 38 above the throat 39, there is a nozzle 40 for spouting pressurized gas that opens downward.
is installed. The other end of the auxiliary outlet pipe 45 is connected to the throat 39 of the outlet pipe 38.

In this dust-containing gas treatment device, the dust-containing gas introduced from the inlet pipe 37 is guided into the dust-containing gas passage 34 from below the filter In, passes through the filter wall of the filter (2), becomes clean gas, and enters the clean gas passage. 35 and flows upward through the outlet pipe 38.
is discharged from. A part of the dust-containing gas passes through the particulate bag section 41, passes through the auxiliary filter 43, becomes clean gas, and further passes through the auxiliary outlet pipe 45, joins the clean gas in the outlet pipe 38, and is discharged. be done. In this way, most of the particulates contained in the dust-containing gas are captured and removed by the filter wall of the filter IO, and some part of the particulates by the auxiliary filter 43. Some of the particulates captured by the filter 10 adhere to the inner wall of the dust-containing gas passage 34, while other particulate bags fall into the part 41 and are deposited on the auxiliary filter 43.

In this device as well, the dust-containing gas passage 34 of the filter lO
When particulates accumulate on the inner wall of the pipe 38 and the pressure loss of the gas increases, backwashing is performed. Backwashing is performed by jetting pressurized gas from a nozzle 40 disposed in the outlet pipe 38. When the pressurized gas is ejected from the nozzle 40 , the gas around the nozzle 40 is attracted by the escator effect in the throat 39 , and several times the amount of pressurized gas initially flows as a pulse flow from the outlet pipe 38 to the filter 10 . It flows into the clean gas passage 35. This backwash air flow passes through the filter wall of the filter IO and flows into the dust-containing gas passage 34.
Removes fine particles adhering to the inner wall of the

On the other hand, the pressurized gas ejected from the nozzle 40 flows into the outlet pipe 38.
When passing through the throat 39 of the air, gas is also attracted from the auxiliary outlet pipe 45 connected to the throat 39. As a result, an airflow is generated in which the particulate bag passes through the part 41 from the dust-containing gas passage 34 of the filter 33, passes through the auxiliary filter 43, and flows into the auxiliary outlet pipe 45.
The particulates peeled off from the inner wall of the particulate bag 41 are collected in the auxiliary filter 43 of the particulate bag part 41, and the same backwashing effect as in each of the above-described embodiments can be obtained.

In each of the above-described embodiments, the filter 33.10 and the auxiliary filter 43 can be made of, for example, ceramics, sintered metal, porous glass, etc. Among them, ceramics such as cordierite, which has excellent strength and heat resistance, are used. Particularly preferred.

Further, instead of the electric heater 46, other combustion means such as an oxidation catalyst or a fuel fluid combustion burner can be used.Furthermore, without providing this combustion means, the particulates accumulated on the filter 43 can be taken out without being burned. , and may be taken out from the tube 44.

"Effects of the Invention" As explained above, according to the present invention, by operating the suction means in synchronization with the operation of the backwashing means during backwashing operation, the particulate bag is removed from the dust-containing gas passage and the auxiliary filter is removed. Since an airflow is generated through the dust-containing gas passage to the auxiliary outlet pipe, it is possible to prevent particulates that have fallen off from the inner wall of the dust-containing gas passage from flowing back into the inlet pipe, and to prevent particles that have accumulated in the particulate bag from scattering. Most of the particulate bag can be collected on the auxiliary filter to enhance the backwashing effect.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the dust-containing gas treatment apparatus of the present invention, FIG. 2 is a longitudinal sectional view showing the second embodiment of the dust-containing gas treatment apparatus of the present invention, and FIG. FIG. 4 is a longitudinal cross-sectional view showing a third embodiment of the dust-containing gas treatment apparatus of the present invention, FIG. 5 is a longitudinal cross-sectional view showing the fourth embodiment of the dust-containing gas treatment apparatus of the present invention, and FIG. Fig. 6 is a perspective view of the filter used in
~A perspective view of a filter used in the third embodiment, and FIG. 7 is a vertical cross-sectional view showing a previously proposed dust-containing gas treatment device. 31 is a casing, 33 is a filter, 34 is a dust-containing gas passage, 35 is a clean gas passage, 37 is an inlet pipe, 38 is an outlet pipe, 39 is a throat, 40 is a nozzle, 41 is a particulate bag, 42 is a tray, 43 is an auxiliary filter, 44 is an ash outlet, 45 is an auxiliary outlet pipe, 46 is an electric heater, and 48 is a suction fan. 2nd WJ f771B Do-, sticky υ 11 positive? ! ? March 22, 1986

Claims (8)

[Claims] 1. a filter having a dust-containing gas passage and a clean gas passage separated by a filter wall; an introduction pipe for introducing dust-containing gas into the dust-containing gas passage; A lead-out pipe that leads out the clean gas flowing into the gas passage, a backwashing means that intermittently generates a gas flow that flows from the clean gas passage through the filter wall to the dust-containing gas passage, and the dust-containing gas passage. an auxiliary outlet pipe is connected to the particle receiver via an auxiliary filter that captures the particles and allows gas to pass through, and the auxiliary outlet pipe A dust-containing gas processing apparatus characterized in that a suction means that operates in synchronization with the backwashing means is provided. 2. In claim 1, the backwashing means is a dust-containing gas processing device comprising a pressurized gas injection nozzle arranged in the outlet pipe so as to open toward the upstream side of the flow of clean gas. . 3. The dust-containing gas processing device according to claim 2, wherein the outlet pipe is provided with a throat having a reduced diameter, and the nozzle is disposed downstream of the throat in the flow of clean gas. 4. The dust-containing gas processing device according to claim 3, wherein the suction means is configured by connecting the auxiliary outlet pipe to the throat of the outlet pipe. 5. In claim 1, the outlet pipe is provided with a valve, the auxiliary outlet pipe is connected to the upstream side of the flow of clean gas than the valve, and the outlet pipe is connected to the outlet pipe within the auxiliary outlet pipe. A dust-containing gas processing device in which the backwash means and the suction means are configured by disposing a nozzle for spraying pressurized gas that opens toward the flow direction of the dust. 6. 6. The dust-containing gas processing device according to claim 5, wherein the auxiliary outlet pipe is provided with a throat having a reduced diameter, and the nozzle is disposed upstream of the throat in the gas flow. 7. In any one of claims 1 to 6,
A dust-containing gas processing device, wherein a particulate combustion means is provided near the auxiliary filter. 8. In any one of claims 1 to 7,
A dust-containing gas processing device, wherein an outlet for taking out the particulates is provided near the auxiliary filter.