JPH1071316A - Backwashing regeneration type exhaust gas cleaner apparatus and regeneration method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a backwashing regeneration type exhaust gas cleaner apparatus which can backwash continuously and efficiently during the operation of the apparatus. SOLUTION: A backwashing regeneration type exhaust gas purifying apparatus composed of two systems of exhaust gas passages of a passage A having a filter A1, a valve A2 for shutting off the passage, and a nozzle A3 for jetting backwashing air to the filter A1, a passage B having a filter B1, a valve B2 for shutting off the passage, and a nozzle B3 for jetting backwashing air to the filter B1, and a passage C which communicates with two systems of exhaust gas passages installed on the exhaust gas introduction side of the filter A1 and the filter B1 and has a filter C1, a valve C2 for shutting off the passage, and a nozzle C3 for supplying burning air to the filter C1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for removing particulates (particulate matter) in exhaust gas discharged from an internal combustion engine. More particularly, the present invention relates to continuous regeneration of a filter for removing particulates. The present invention relates to a backwash regenerative exhaust gas purifying apparatus that can be carried out efficiently.

[0002]

2. Description of the Related Art Recently, it has become a problem that particulates contained in exhaust gas discharged from internal combustion engines such as vehicles such as buses and trucks and construction machines cause harm to the environment and human bodies. The exhaust gas purification device is provided in an exhaust passage of an internal combustion engine, and captures and removes particulates in exhaust gas by a filter.

It is necessary to provide a device for regenerating a filter by removing trapped particulates in an exhaust gas purification device. As a regeneration method using such an apparatus, there has been conventionally known a method in which heat is directly supplied to a filter and the particulate is incinerated by the heat.
However, this method has a problem that the filter is melted by the heat of combustion of the particulates or the filter is damaged by thermal stress.

As a method for regenerating particulates in a filter without burning them, a high-speed airflow is supplied from a direction opposite to the flow of exhaust gas, and the particulates trapped by the filter are removed by the airflow. There is known a backwashing regeneration system in which particulates are incinerated in an existing container using an electric heater.

[0005] When this backwashing regeneration system is used, it is not necessary to supply high heat for regeneration directly to the filter. Therefore, there is no damage to the filter due to thermal stress, no ash is deposited in the filter, and the filter is clogged. Is unlikely to occur.

However, when a series of these operations are performed by one filter, the back pressure in the engine exhaust pipe increases in the process of removing particulates, which adversely affects the operability. Therefore, a method of alternately regenerating filters using two sets of filters has been proposed (Journal of the Marine Engineering Society of Japan, Vol. 27, No. 6, (1992-1996)).

In this method, as shown in FIG.
The backwash regenerative exhaust gas purifier includes a filter A (1) and a filter B (4), and the exhaust gas passes through the filter A (1) and the filter B (4) in a normal state. When the regeneration of the filter A is performed, as shown in FIG. 5, the filter A is used to prevent the backwash air from flowing out to the exhaust outlet.
Close the valve (2) between (1) and the exhaust outlet. Next, as shown in FIG. 6, the compressed air is instantaneously injected from the nozzle (3) to remove the particulates accumulated in the filter and to regenerate the filter. After playing the filter,
As shown in FIG. 7, the valve (2) is opened again to perform particulate removal using two ordinary sets of filters.

[0008] In these series of processes, the filter B
Exhaust gas flows through (4) as usual, and particulate removal is performed continuously. The regeneration of the filter B (4) is performed in the same manner as the regeneration of the filter A (1) described above.

The exhaust gas purifying apparatus using the two sets of filters can continuously perform backwashing while removing particulates continuously. Therefore, the exhaust gas purifying apparatus can be used for a long time in a truck traveling a long distance or in a place where ventilation is not possible. It can be used for an internal combustion engine that operates continuously.

However, in this method, there is a problem that the particulates removed from one filter contaminate the other filter, a combustion air introduction pipe for burning the particulates, and the like.

Further, the conventional backwashing regeneration type exhaust gas purifying apparatus
When the inflow of exhaust gas was stopped due to the stop of the internal combustion engine, the operation was stopped, so the combustion of the backwashed particulates was often stopped halfway, and in the state where the particulates remained, Next, when the inflow of exhaust gas is started, there are problems such as a low particulate removal efficiency and an increase in pressure loss.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and a backwash regeneration type exhaust gas purifying apparatus which can continuously and efficiently perform backwashing when the exhaust gas purifying apparatus is operated. And a reproducing method thereof.

[0013]

The present invention relates to a filter A
1. A valve A2 provided on the exhaust outlet side of the filter A1 for shutting off a passage and a nozzle A3 provided between the filter A1 and the valve A2 for injecting backwash air to the filter A1. Having a passage A,
A filter B1, a valve B2 provided on the exhaust gas outflow side of the filter B1 for shutting off a passage, and a valve B2 provided between the filter B1 and the valve B2 for injecting backwash air to the filter B1. The two exhaust passages of the passage B having the nozzle B3 and the two exhaust passages provided separately from the exhaust inflow passage on the exhaust inflow side of the filter A1 and the filter B1 communicate with the two exhaust passages. A valve C2 provided on either side of C1 for shutting off a passage and a nozzle C provided between the filter C1 and the valve C2 for supplying combustion air to the filter C1.
3 is a backwash regenerative exhaust gas purifying apparatus, comprising:

A second aspect of the present invention relates to a filter A1, a valve A2 provided on the exhaust outlet side of the filter A1 for shutting off a passage, and the filter A1 and the valve A
2, a passage A having a nozzle A3 for injecting backwash air to the filter A1, and a valve B2 provided on the exhaust outlet side of the filter B1 and the filter B1 for shutting off the passage. And two exhaust passages, a passage B provided between the filter B1 and the valve B2 and having a nozzle B3 for injecting backwash air to the filter B1, and exhaust of the filter A1 and the filter B1. The filter C1, a valve C2 provided on either side of the filter C1 for shutting off the passage, the filter C1 and the filter C1 being provided separately from the exhaust inflow passage on the inflow side and communicating with the two exhaust passages. And a passage C having a nozzle C3 for supplying combustion air to the filter C1 provided between the filter C1 and the valve C2. After the exhaust gas passes through the passage A and the passage B in a state where the valve A2 and the valve B2 of the washing regeneration type exhaust purification device are open, and the particulates in the exhaust gas are captured by the filter A1 and the filter B1, After the valve A2 is closed and the valve C2 is open, backwash air is injected from the nozzle A3 to remove the particulates in the filter A1, and to capture the particulates in the filter C1. The valve A2 is opened, the valve C2 is closed, and the combustion air is supplied from the nozzle C3 to the filter C1.
A first regeneration process for burning the particulates inside,
After the valve B2 is closed and the valve C2 is open, backwash air is injected from the nozzle B3 to remove the particulates in the filter B1, and to capture the particulates in the filter C1. , The valve B
2 is opened, the valve C2 is closed, and the nozzle C
And a second regeneration process for supplying the combustion air from 3 and burning the particulates in the filter C1 alternately.

According to a third aspect of the present invention, when the regeneration method of the second aspect of the present invention is stopped, after the flow of exhaust gas into the passages A and B is stopped, the first regeneration process or the second regeneration process is performed. A method for regenerating a backwash regenerative exhaust gas purifying apparatus, wherein one of the regenerating processes is completed.

In a fourth aspect of the present invention, when the regeneration method of the second aspect of the invention is started, after the flow of exhaust gas into the passage A and the passage B is started, the first regeneration process or the second A method for regenerating a backwash regenerative exhaust gas purifying apparatus, characterized by initiating one of regenerating processes.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a backwash regenerative exhaust gas purifier of the present invention and a second method of regenerating a backwash regenerative exhaust gas purifier of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a normal operation state of a backwash regenerative exhaust gas purifying apparatus according to one embodiment of the present invention, and FIG. FIG. 3 is a diagram showing a normal operation of the backwashing regenerative exhaust gas purifying apparatus according to one embodiment of the present invention and a regenerating state of the filter C1.

The backwash regeneration type exhaust gas purifying apparatus of the present invention is provided in a passage connected to the exhaust side of an internal combustion engine, and the passage is provided with:
It is configured such that it is divided into two directions, a passage A and a passage B, in front of the exhaust purification device, and exhausts to outside air behind the exhaust purification device.

The passage A includes a filter A1, a filter A
No. 1 provided on the exhaust gas outflow side for shutting off a passage and a nozzle A provided between the filter A1 and the valve A2 for injecting backwash air to the filter A1.
The passage B is provided with a filter B1, a valve B2 provided on the exhaust gas outflow side of the filter B1, and a valve B2 for shutting off the passage, and a backwash air provided between the filter B1 and the valve B2. And a nozzle B3 for injecting.

On the other hand, filter A1 and filter B1
A passage C provided separately from the exhaust gas inflow passage on the exhaust inflow side and communicating the two exhaust passages is provided with a filter C1 and a valve C2 and a filter C1 provided on either side of the filter C1 for shutting off the passage. And a nozzle C3 provided between the valve C2 and the filter C1 for supplying combustion air to the filter C1.

As shown in FIG. 1, during normal operation of the exhaust gas purifying apparatus, exhaust gas is passed through the passages A and B with the valves A2 and B2 opened and the valve C2 closed. The particulates in the exhaust from the internal combustion engine are captured by the filter A1 and the filter B1.

As shown in FIG. 2, after the particulates have been captured by the filter A1 for a certain period of time, when the filter A1 is backwashed, the valve B2 is operated with the valve B2 closed while the valve B2 is closed and the valve C2 is closed. Is opened, backwash air is instantaneously ejected from the nozzle A3 to remove the particulates in the filter A1, and to guide and capture the particulates in the filter C1.

As shown in FIG. 3, after the filter A1 is backwashed, the valve A2 is opened and the valve C2 is closed, and the combustion air is supplied from the nozzle C3 and heated by, for example, a heater. By means, the particulates in the filter C1 are burned, and the air after the removal of the particulates is guided forward of the filter A1, mixed with the exhaust gas of the internal combustion engine, and introduced into the filter A1. These series of operations are a first regeneration process.

On the other hand, after the particulates are captured on the filter B1 for a certain period of time, when the filter B1 is backwashed,
When the valve A2 is opened and the filter A1 is operated, the valve B2 is closed and the valve C2 is opened, and the backwash air is instantaneously injected from the nozzle B3 to remove the particulates in the filter B1. Induce and capture particulates in the filter C1.

After the filter B1 is backwashed, the valve B2 is opened and the valve C2 is closed, and combustion air is supplied from the nozzle C3, and the inside of the filter C1 is heated by, for example, a heater. The particulates are burned, and the air from which the particulates have been removed is guided forward of the filter A1, mixed with the exhaust gas of the internal combustion engine, and introduced into the filter A1. These series of operations are a second regeneration process. In the present invention, the operation of the exhaust gas purification device is continuously performed, and the first regeneration process and the second regeneration process are alternately repeated.

The backwashing regeneration type exhaust gas purifying apparatus of the present invention can alternately perform the backwashing of the filter A1 and the filter B1, so that the backwashing can be performed while the operation of the exhaust gas purifying apparatus is continued. The backwashing regenerative exhaust gas purifying device of the present invention captures backwashed particulates by the filter C1, so that dirty air does not leak out of the device, and the filter on the opposite side of the backwashed filter, There is no contamination of the device such as the nozzle C3 for assisting combustion.

The backwash regenerating exhaust gas purifying apparatus of the present invention performs particulate combustion in the filter C1 immediately after the backwash while alternately performing the backwash, so that the pressure loss can be kept constant. In the backwashing regenerative exhaust gas purifying apparatus of the present invention, the air subjected to backwashing from the reverse direction enters at the time of the next backwashing, so that unburned particulates remaining after the combustion of the filter C1 are blown out from the filter C1. Are captured again by the filter A1 or the filter B1, and do not remain in the filter C1.

The backwash regenerating type exhaust gas purifying apparatus of the present invention has a single filter for supplementing the particulates backwashed from the filter A1 or the filter B1, so that the particulates have a good dust collection property and the backwash regenerating system has a good effect. The closed-type exhaust gas purification system can be made a closed system, the device can be easily manufactured, and the device can be downsized.

The backwash regenerating type exhaust gas purifying apparatus of the present invention can control the flow of air only by controlling the opening and closing operation of the valve by the sequencer. Does not adversely affect sex. Since the backwashing regenerative exhaust gas purifying apparatus of the present invention can be operated continuously for a long time, the internal combustion engine can be operated for a long time, for example, a truck that operates for a long distance for a long time; a tunnel, a coal mine, etc. It can be suitably used for an internal combustion engine or the like used inside a vehicle.

Hereinafter, one embodiment of a method for regenerating a backwash regenerative exhaust gas purifying apparatus according to the third aspect of the present invention will be described. In the third aspect of the present invention, when the regeneration method of the second aspect of the invention is stopped, after stopping the flow of exhaust gas into the passage A and the passage B, the first regeneration process or the second regeneration process is performed. Complete one of

In this specification, "stopping the inflow of exhaust gas" means that the inflow of exhaust gas into the backwash regenerative exhaust gas purifying device is stopped with the stop of the internal combustion engine. In the third aspect of the present invention, after the internal combustion engine is stopped, either the first regeneration process or the second regeneration process is completed, so that during the next operation, the particulates in the filter C1 are removed. The flow of exhaust gas can be restarted, and thereby the particulate removal operation and the regeneration process can be performed efficiently. When the flow of exhaust gas is restarted with the particulates remaining in the filter C1 and the first regeneration process or the second regeneration process is performed, the air in the filter C1 is subjected to backwashing. The pressure returns to the filter on the opposite side, so that the particulate removal efficiency is poor and the pressure loss may increase. When performing the regeneration process after restarting the inflow of exhaust gas, it is preferable to perform the regeneration process from the filter that is not performing the regeneration process at the time of stop.

Hereinafter, one embodiment of the regeneration process of the backwash regeneration type exhaust gas purification apparatus of the fourth invention will be described. In the fourth aspect of the present invention, when starting the regeneration method of the second aspect of the present invention, after the flow of exhaust gas into the passage A and the passage B is started, the first regeneration process or the second regeneration process is performed. To start one.

In the present specification, "starting the flow of exhaust gas" means that the flow of exhaust gas into the backwash regenerative exhaust gas purifying device has started with the start of the internal combustion engine. According to the fourth aspect of the present invention, since either the first regeneration process or the second regeneration process is started immediately after the start of the internal combustion engine, the particulate removal in the filter C1 is removed. The operation and the next regeneration process can be performed, whereby the particulates can be removed efficiently. When the first regeneration process or the second regeneration process is performed in a state where the particulates at the time of the previous operation remain in the filter C1, the particulates in the filter C1 are changed by the pressure of the air subjected to the backwash. As it returns to the filter on the opposite side, the particulate removal efficiency is poor,
Further, the pressure loss may increase.

In the fourth aspect of the present invention, the timing at which either the first regeneration process or the second regeneration process is started may be simultaneous with the start of the inflow of exhaust gas, or the start of the inflow of exhaust gas. However, if the regeneration process is started simultaneously with the start of the inflow of exhaust gas, the filter C1
Power is supplied to the heaters and the like disposed in the first position.
In this case, the electric energy is increased at one time by starting the cell motor, the heater, and the like of the internal combustion engine, and an electric power load is applied. Considering these facts, it is preferable that the timing to start either the first regeneration process or the second regeneration process is a certain time after the start of the exhaust gas inflow. The fixed time may be set to a time required for the rotation of the cell motor of the internal combustion engine, and may be, for example, 60 seconds.

[0035]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A backwash regenerative exhaust gas purification system as shown in FIGS. 8 to 10 was manufactured and its performance was evaluated. An 7000 cc engine was used as the internal combustion engine.
The cycle from 00 to 1800 rpm was repeated. The backwash air was at a pressure of 8 kg / cm ² and the injection time was 0.1 second. The filter A1 and the filter B1 are made of porous silicon carbide, have a partition wall thickness of 0.43 mm, and have 30 holes / square inch.
The filter C1 was made of porous silicon carbide, the partition wall thickness was 0.43 mm, the number of holes was 30 per square inch, and the length was 15 mm.
0 mm and a filter capacity of 0.14 liter were used. The heater for burning the particulates captured by the filter C1 was 24 V-300 W. The pressure of the combustion air was 6.5 kg / cm ² .

The engine was operated, the particulate removal operation was continuously performed, and the filter A1 and the filter B1 were alternately backwashed by the backwashing regeneration type exhaust emission control system of the present invention. FIG. 11 shows a sequence diagram of the backwashing. At the same time as closing valve A2, valve C
2 is opened, and immediately after that, the nozzle A3 is opened to inject backwash air, and then the heater is heated and the filter C1
The particulates trapped in the filter C1 were burned until the temperature reached 70 ° C. Fifteen minutes after the valve A2 was opened, the valve C2 was opened at the same time as the valve B2 was closed. Immediately after that, the nozzle B3 was opened to inject backwash air, and then the heater was heated and the filter C1 was opened.
The particulate matter trapped in the filter C1 was burned until the temperature reached 670 ° C. This operation was repeated.

After the engine is stopped, the filter A1 or the filter B1 is regenerated, and the heater is heated to burn the particulates in the filter C1 until the temperature of the filter C1 reaches 670 ° C. Was stopped.

The pressure loss caused by the backwash regenerating type exhaust gas purifier during operation was stable at 2800 mmH ₂ O or less. 16
After the operation for 00 minutes, the inside of the pipe on the inlet side of the filter A1 and the filter B1 was visually judged, and almost no particulate matter was deposited.

[0040]

As described above, the backwashing regeneration type exhaust gas purifying apparatus of the present invention can continuously and efficiently perform backwashing when the exhaust gas purifying apparatus is operated.

[Brief description of the drawings]

FIG. 1 is a diagram showing a normal operation state of an embodiment of a backwashing regeneration type exhaust gas purification apparatus of the present invention.

FIG. 2 is a diagram showing a backwashing regeneration type exhaust gas purification apparatus according to an embodiment of the present invention at the time of backwashing.

FIG. 3 is a diagram showing a normal operation and a regeneration state of a filter C1 of one embodiment of a backwash regeneration type exhaust gas purification apparatus of the present invention.

FIG. 4 is a diagram showing a normal operation state of a conventional backwashing regeneration type exhaust gas purification apparatus using two sets of filters.

FIG. 5 is a view showing a state in which a valve on a filter A side of a conventional backwash regenerating type exhaust gas purification apparatus using two sets of filters is closed.

FIG. 6 is a view showing a state of a conventional backwashing regeneration type exhaust gas purification apparatus using two sets of filters when the filter A is backwashed.

FIG. 7 is a diagram showing a conventional backwashing regenerative exhaust gas purifier using two sets of filters in a normal operation restarting state.

FIG. 8 is a schematic diagram of a backwash regenerative exhaust gas purifying apparatus according to the first embodiment.

FIG. 9 is a cross-sectional view of the backwash regenerative exhaust gas purifying apparatus according to the first embodiment.

FIG. 10 is a schematic diagram of a backwash regeneration type exhaust gas purification system according to the first embodiment.

FIG. 11 is a sequence diagram of backwashing of the backwash regenerative exhaust gas purifying apparatus according to the first embodiment.

[Explanation of symbols]

 A1 filter A1 A2 valve A2 A3 nozzle A3 B1 filter B1 B2 valve B2 B3 nozzle B3 C1 filter C1 C2 valve C2 C3 nozzle C3 1 filter A2 valve 3 nozzle 4 filter B 5 valve 6 nozzle 10 air tank 11 air compressor 11 air compressor Solenoid valve 14 Regulator 15 Filter C1 Secondary air for combustion

Claims (4)

[Claims] 1. A filter A1, a valve A2 provided on the exhaust gas outflow side of the filter A1 for blocking a passage.
A passage A having a nozzle A3 provided between the filter A1 and the valve A2 for injecting backwash air to the filter A1, and a filter B1,
A valve B2 provided on the exhaust gas outflow side of the filter B1 for shutting off a passage and a nozzle B3 provided between the filter B1 and the valve B2 for injecting backwash air to the filter B1; B, and two exhaust passages, which are provided separately from an exhaust inflow passage on the exhaust inflow side of the filter A1 and the filter B1 and communicate with the two exhaust passages, and one of the filter C1 and the filter C1. And a passage C having a nozzle C3 provided between the filter C1 and the valve C2 for supplying combustion air to the filter C1. Backwash regenerative exhaust purification system. 2. A filter A1, a valve A2 provided on the exhaust gas outflow side of the filter A1 for blocking a passage.
A passage A having a nozzle A3 provided between the filter A1 and the valve A2 for injecting backwash air to the filter A1, and a filter B1,
A valve B2 provided on the exhaust gas outflow side of the filter B1 for shutting off a passage and a nozzle B3 provided between the filter B1 and the valve B2 for injecting backwash air to the filter B1; B, and two exhaust passages, which are provided separately from an exhaust inflow passage on the exhaust inflow side of the filter A1 and the filter B1 and communicate with the two exhaust passages, and one of the filter C1 and the filter C1. Backwash regeneration comprising a valve C2 provided on the side of the filter for shutting off a passage and a passage C provided between the filter C1 and the valve C2 and having a nozzle C3 for supplying combustion air to the filter C1. Exhaust gas passes through the passage A and the passage B when the valve A2 and the valve B2 of the exhaust gas purifying apparatus are open, Iruta A1 and the filter B
After capturing the particulates in the exhaust gas at 1, the valve A2 is closed and the valve C2 is opened, and backwash air is injected from the nozzle A3 to remove the particulates in the filter A1. After trapping the particulates in the filter C1, opening the valve A2,
A first regeneration process in which the valve C2 is closed and combustion air is supplied from the nozzle C3 to burn the particulates in the filter C1;
Is closed and the valve C2 is open, backwashing air is injected from the nozzle B3 to remove the particulates in the filter B1, and the particulates are captured in the filter C1. B2 is opened, the valve C2 is closed, and the second regeneration process in which the combustion air is supplied from the nozzle C3 to burn the particulates in the filter C1 is alternately repeated. A method for regenerating a backwash regenerative exhaust purification system. 3. When stopping the regeneration method according to claim 2, the flow of exhaust gas into the passage A and the passage B is stopped, and then either the first regeneration process or the second regeneration process is performed. A method for regenerating a backwash regenerative exhaust gas purifying device, wherein the method is completed. 4. When starting the regeneration method according to claim 2, after starting the flow of exhaust gas into the passage A and the passage B, either the first regeneration process or the second regeneration process is performed. A method for regenerating a backwash regenerative exhaust gas purification apparatus, characterized by starting.