JPH0318610A - Backwash type filter system - Google Patents

Abstract

PURPOSE:To avoid exhaust gas from directly discharging to the atmosphere even at the time of backwashing by constructing the system in the title by two scavenge chambers connected to the half way of an exhaust pipe and a dust collecting chamber which is connected to the inlet of the scavenge chamber and opened to the atmosphere. CONSTITUTION:A backwash type filter system 10 is constructed by containing scavenge chambers 11, 12 which are provided with ceramic honeycombs 28, 29 washed by a backward air flow and connected to the half way of the exhaust gas pipe 63 of an engine 60, and a dust collecting chamber 13 connected to the gas inlets 36, 37 of the scavenge chambers 11, 12. An opening 45 to which a soot scavenge filter 46 is fitted is provided in the dust collecting chamber 13. Soot is separated from the filters 28, 29 by the backward air current and is collected in the dust collecting chamber 13, at this time, compressed air flowing in the dust collecting chamber 13 is discharged through the opening 45 to the atmosphere. Consequently, even at the time of cleaning the filters 28, 29 by the backward air current, exhaust gas is avoided from discharging from the engine 60 directly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to backwash filter systems used in automobile exhaust systems.

Background Art Recently, backwash type dust collectors have been developed for trucks and buses equipped with diesel engines to collect soot (black smoke) contained in the exhaust gas. The dust device is divided into a ceramic honeycomb filter section and a soot storage section within the casing, and is constructed to clean the ceramic honeycomb filter with a backflow of air. , the soot collected in the soot storage area is
It was returned to the honeycomb filter again, making it difficult to improve the backwashing effect, and on top of that, the casing became large, making it extremely difficult to install it in a car. The purpose and problem of the invention is to secure a sufficient amount of gas throughput for the engine, and also when cleaning the filter with reverse airflow.
Avoiding direct emission of exhaust gas from the engine to the atmosphere, improving the backwashing effect, and suppressing soot that has been stripped and collected from the filter by backwashing from being returned to the filter, and The purpose of the present invention is to provide a backwash filter system that is small and lightweight enough to be installed in a car, and that can also be used in the exhaust system of a car.

Summary of the above-mentioned invention: Contents of the claimed invention In relation to the above-mentioned objects and problems, the backwash type filter system of the present invention first uses a ceramic filter that is cleaned by backflow.・The system includes two collection chambers equipped with honeycomb filters and connected in parallel in the middle of the exhaust pipe of the engine, and a dust collection chamber connected to the entrance of the collection chambers. When one of the chambers is collecting soot from the exhaust of the engine, the other of the collection chambers is enabled to be flushed with reverse airflow, and whenever the engine is running, the other of the chambers is enabled to collect soot from the exhaust; In addition, ceramics, honeycomb, etc. that are cleaned by reverse airflow are used.
It includes two collection chambers equipped with filters and connected in parallel in the middle of the exhaust pipe of the engine, and a dust collection chamber connected to the entrance of the collection chambers and opened to the atmosphere through the filter. When one of the collection chambers is collecting soot from the engine exhaust, the other of the collection chambers can be cleaned by backflow; The soot exfoliated from the ceramic honeycomb filter of the other collection chamber is collected in the dust collection chamber while the soot is released into the atmosphere through its filter, and whenever the engine is running, the exhaust gas is The purpose is to make it possible to collect soot from the air.

Description of Specific Examples Specified specific examples of the backwash filter system of the present invention will be described below with reference to the drawings.

The figure shows a diesel engine mounted on a truck (not shown).
A specific example lO of the backwash type filter system of the present invention is shown arranged in the exhaust system 61 of an engine 60. The backwash filter system 10 includes two collection chambers 1
1, 12, dust collection chamber l3, and two filter valves 14
, 15, two filter outlet valves l6, 17, two trap population valves 18, 19, and a second backwash valve 20, 21.
, an air tank (not shown), and a sheathed heater 22
and a controller 23. The collection chambers l1 and l2 have a normal structure in which the exhaust system 6l includes an exhaust manifold 62, an exhaust pipe 63, a muffler (not shown), and a tail pipe (not shown). They were connected in parallel in the middle of the exhaust pipe 63 on the upstream side of the muffler. In addition, each of the collection chambers 11 and 12 is provided with a horizontal cylindrical casing 26.
, 27 and a ceramic honeycomb filter 2, 29 placed within its casing 26, 27 and cleaned with reverse airflow.

The casings 26, 27 have cylindrical body walls 30, 3l,
A front end wall 32 that closes off the front ends of the cylindrical body walls 30 and 31;
33 and rear end walls 34 and 35 that close the rear ends of the cylindrical body walls 30 and 31, and furthermore, the gas inlet 3
6, 37 has a gas outlet 38 in its front end wall 32, 33.
, 39 are provided on the rear end walls 34, 35, respectively.

Of course, the gas ports 36 and 37 are located on the exhaust manifold 62 side, and the gas outlets 38 and 39 are located on the muffler side, respectively, and are connected to the exhaust pipe 63.

The cellar honeycomb filters 28 and 29 have a honeycomb structure consisting of a large number of cells, and both ends of the cells are sealed in a houndstooth check pattern, dried, and then burned. It was done.

The dust collection chamber 13 is connected to the gas inlet 3 of the collection chambers 11 and 12.
Connected to 6 and 37.

Further, the dust collection chamber 13 is manufactured in a tank 40 that is open to the atmosphere, and two traps 43 and 44 are provided on the front end wall 41 of the tank 40, and a soot collection filter 46 is provided in the tank 40. It was assembled into an opening 45 formed in the rear end wall 42 of the tank 40, and a soot sump 47 was formed at its bottom. Of course, the dust collection chamber 13 is connected with its trap populations 43, 44 corresponding to the gas populations 36, 37 of its collection chambers 11, 12, and its ceramic honeycomb filters 28, 29 are alternately reversed. When being washed, the compressed air used for backwashing is released into the atmosphere from the opening 45 while passing through the soot collection filter 46,
More of the soot (particulates) collected in the ceramic honeycomb filters 28 and 29 is exfoliated, and more of the exfoliated soot is accepted while suppressing the return of the soot, thereby backwashing. We are trying to improve efficiency.

Of course, this soot collecting filter 46 is... The ceramic
A material with considerably lower heat resistance than the honeycomb filters 28 and 29 is sufficient.

The filter valves 14 and 15 each have a valve part and a driving part, and in this case, electromagnetic valves were used. In particular, a normally open solenoid valve was used for the filter valve 14, and a normally closed solenoid valve was used for the filter valve 15.

The solenoid valve 14 is arranged in the exhaust pipe 63 upstream of the gas inlet 36 of the collection chamber l1 and electrically connects the solenoid coil 48 to the output side of the controller 23.

On the other hand, the solenoid valve 15 controls the gas population 3 of the collection chamber 12.
7 is located in its exhaust pipe 63 and has a solenoid coil 49 electrically connected to the output side of its controller 23 .

For the filter outlet valves 16 and 17, normally open solenoid valves and normally closed solenoid valves manufactured in the same manner as the above-mentioned filter artificial valves 14 and 15 were used.

The normally open solenoid valve 16 is connected to the gas outlet 3 of the collection chamber 11.
8 is located in its exhaust pipe 63 and has a solenoid coil 50 electrically connected to the output side of its controller 23 .

On the other hand, the normally closed solenoid valve 17 is arranged in the exhaust pipe 63 downstream of the gas outlet 39 of the collection chamber l1,
Then, the solenoid coil 51 is connected to the controller 2.
It is electrically connected to the output side of 3.

The trap inlet valves 18 and 19 are electromagnetic valves like the filter population valves 14 and 15 and the filter outlet valves 16 and 17, but normally closed types were used.

The solenoid valves 18 and 19 are arranged corresponding to the trap populations 43 and 44 of the dust collection chamber l3, and the solenoid coils 52 and 53 are electrically connected to the output side of the controller 23.

The backwash valves 20, 2l are normally closed solenoid valves, and are arranged corresponding to pneumatic pipes 56, 57 that connect the air tanks to the gas outlets 38, 39 of the collection chambers 11, 12,
Solenoid coils 54 and 55 are electrically connected to the output side of the controller 23.

The air tank was attached to the frame of the truck via a bracket (not shown) near the gas outlets 38, 39 of the collection chambers 11, 12.

This air tank also has an air inlet (not shown).
The pneumatic pipe 56 is connected to the compressor/dispenser (not shown) through a pipe (not shown), and the air pressure pipe 56 is connected to the outlet (not shown).
57 is connected.

As such, the gas outlets 38, 3 of the collection chambers 11, 12
The air tank placed close to the air tank 9 allows the pneumatic piping 56, 57 to be shortened and made thinner, and the backwash valves 2o, 2l can be made smaller accordingly.
A cleaning nozzle can be omitted, and compressed air with a large flow rate and flow velocity can be jetted into the collection chambers l1 and 12.

The sheathed heater 22 is incineration means, and is arranged in the soot sump 47 of the dust collection chamber l3, and is electrically connected to the output side of the controller 23.

The controller 23 has pressure sensors 24 and 2 on the input side.
5, and the output side is connected to the solenoid coils 48, 49 of the filter population valves 14, 15, filter outlet valves 16, 17, trap population valves 18, 19, and backwash valves 20, 21, respectively. 50, 51, 52, 53, 54
, 55 and is also electrically connected to the sheathed heater 22 thereof.

Then, this controller 23 alternately uses the collection chambers 11 and 12 to collect the soot, and uses the collection chambers 11 and 12 alternately to collect the soot.
When one of the two chambers 11 is collecting soot from the exhaust gas of the diesel engine 60, the ceramic honeycomb filter 29 of the other one of the collection chambers 11 and 12 is cleaned by reverse air flow, and the diesel engine In such a way, when the engine 60 is in operation, the diesel engine 60
The pressure sensor 24 controls the backwash type filter system 10 to perform soot collecting operation and filter cleaning operation without interfering with the operation of the backwash filter system 10.
, 25, its solenoid coil 4
8, 49, 50, 51, 52, 53, 54, 55, and the valves 14, 15, 16, 17, l
A backwash program that determines the opening/closing timing and opening time of the valves for selectively opening/closing the valves 8, 19, 20, and 21, that is, the start and time of energization of the output current, is input in advance.

As such, the controller 23 controls the diesel engine on the condition that the ceramic honeycomb finoretors 28, 29 are clogged, in other words, under a condition corresponding to the clogging. On the condition that the back pressure of the exhaust gas discharged from the valve 60 exceeds a predetermined value, the valves 14, l5, 16, 17, 18, 1
9, 20, and 21, and consists of an input and output circuit, a memory circuit, an arithmetic circuit, a control circuit, and a power supply circuit.The power supply circuit also connects the truck's battery (Fig. (not shown) are shared.

The pressure sensors 24 and 25 are arranged corresponding to the gas populations 36 and 37 of the collection chambers 11 and 12, and sense the back pressure of the exhaust gas discharged from the diesel engine 60, and respond to an electrical signal. and provides the signal to its controller 23.

That is, the pressure sensors 24, 25 detect whether the ceramic honeycomb filters 28, 29 are clogged. Next, the operation of the backwash filter system 10 that collects soot from the exhaust gas of the diesel engine 60 will be described.

Now, its filter population valve 14 and filter outlet valve 16
is opened, while its filter population valve 15, filter outlet valve 17, trap population valve 18, 19, and backwash valve 2
0 and 21 are closed, the exhaust gas discharged from the diesel engine 60 flows from the exhaust manifold 62 upstream of the exhaust pipe 63 and from the gas inlet 36 into the ura collection chamber 1l.

The exhaust gas then passes through the ceramic honeycomb filter 28. , flows to its gas outlet 38. At that time, the soot contained in the exhaust gas is collected by the ceramic honeycomb filter on the second day, and the exhaust gas becomes clean exhaust gas from the gas outlet on the third day. It flows downstream and then through its muffler and tail pipe to the atmosphere.

As such conditions continue, the ceramic honeycomb filter 28 becomes clogged with the soot.
The pressure upstream of the exhaust pipe 63 and within the gas inlet 36 increases and exceeds a predetermined value corresponding to the clogging state of the ceramic honeycomb filter 28. The pressure that has increased beyond the predetermined value is sensed by the pressure sensor 24, converted into an electrical signal, and given to the controller 23, so the controller 23 performs calculations based on the electrical signal. , the calculated value exceeds the predetermined pressure side, so the solenoid coil 5 is operated for a certain period of time based on the backwash program.
1, 49, 48, 50, 52, and 54. Of course, those solenoid coils 51, 49, 48, 50,
Current flows through 52 and 54 with a predetermined time lag.

First, the solenoid coils 51 and 49 are sequentially energized, so that the filter outlet valve 17 and the filter population valve 15 are sequentially opened, and the diesel engine 6
The exhaust gas discharged from 0 flows from the exhaust manifold 62 upstream of the exhaust pipe 63, begins to flow into the collection chamber 12 from the gas population 37, and then passes through the ceramic honeycomb filter 29. Further, the gas begins to flow from the gas outlet 39 to the downstream side of the exhaust pipe 63, the muffler, and the tail pipe, and the collection chamber l
2, soot collection begins.

Then, after a predetermined time lag, the solenoid
As current flows through the coils 48, 50, 52 in sequence, the filter population valve 14 and the filter outlet valve 16 are sequentially closed, and the trap population valve 1B is opened.

Subsequently, after a predetermined time lag, the solenoid coil 54 is energized for a very short period of time, so that the backwash valve 20 momentarily opens and closes, opening the pneumatic line 56. Then, a large amount of compressed air is instantaneously flowed from the air tank to the gas outlet 28.

The large amount of compressed air is blown into the collection chamber 11 from the gas outlet 38 in a direction counter to the flow direction of the clean exhaust gas.

In the collection chamber 11, the compressed air blown in the opposite direction passes through the ceramic honeycomb filter 2.
8, in doing so exfoliating the soot from the ceramic honeycomb filter 28 and conveying the exfoliated soot to the gas port 36 and from the trap population 43 to the dust collection chamber 12. and thus transports the soot to the dust collection chamber 13. At that time, the compressed air that has flowed into the dust collection chamber 13 is released into the atmosphere from the opening 45 where the soot collection filter 46 is assembled, so that the collected soot is・Honeycomb・
The dust was efficiently separated from the filter and led to the dust collection chamber l3, improving the backwashing efficiency.

Then, the soot carried to the dust collection chamber 13 is transferred to the soot pool 4.
7, where the sheathed heater 22
will be incinerated.

Once the instantaneous energization time has elapsed, the current flowing through the solenoid coil 54 is transferred to the controller 2.
3, so its backwash valve 20 is closed;
Cleaning is complete.

In this manner, when the backwashing of the collection chamber 11 is completed, the current flowing through the solenoid coil 52 is cut off by the controller 23, the trap population valve 18 is closed, and the collection chamber l2 Soot collection is carried out at

If such a state continues, the ceramic honeycomb filter 29 will become clogged with soot, and the pressure on the upstream side of the exhaust pipe 63 and in the gas inlet 37 will increase, causing the ceramic honeycomb filter 29 to become clogged with soot. - Increases above a predetermined value corresponding to the clogging of the two honeycomb filters.

The pressure that has increased beyond the predetermined value is sensed by the pressure sensor 25, converted into an electrical signal, and given to the controller 23, so the controller 23 performs calculations based on the electrical signal. , based on the backwash program, these filter outlet valve 16, filter population valve 14, filter population valve 15, filter outlet valve 1
7. The trap population valve 19 and the backwash valve 2l are operated by valve switching, and the filter cleaning operation is performed in the collection chamber 12.
In each of the collection chambers 1l, a soot collection operation is performed.

The backwash filter system 10 then repeats the above operations while the diesel engine 60 is operated to drive the truck.

In the backwash filter system 10 described above, the dust collection chamber 13 is formed in the rear end wall of the tank 40 and has an opening 45.
Although the dust collection chamber 13 has been described as having the soot collection filter 46 assembled therein, the dust collection chamber 13 may be manufactured as a dead volume tank without the opening 45 and the soot collection filter 46.

Advantages and Benefits of the Invention As can be seen from the foregoing, the backwash filter system of the present invention first uses a ceramic filter that is cleaned by backflow.
It is equipped with two collection chambers equipped with honeycomb filters and connected in parallel in the middle of the engine exhaust pipe, and a dust collection chamber connected to the entrance of the collection chambers. There are two collection chambers connected in parallel in the middle of the engine's exhaust pipe, each equipped with a ceramic honeycomb filter that is cleaned with water, and connected to the inlet of the collection chambers, which are then opened to the atmosphere through the filters. Since the backwash type filter system of the present invention includes a dust collection chamber,
The gas throughput is sufficient and when cleaning the ceramic honeycomb filter with reverse airflow, the exhaust gas is not released directly from the engine into the atmosphere. The cleaning efficiency is improved to ensure that the exfoliated soot is collected in the dust collection chamber without being returned to the ceramic honeycomb filter, thus interfering with engine operation. Backwashing of the ceramic honeycomb filter is now possible, especially when backwashing soot from the ceramic honeycomb filter is carried out from the collection chamber to the atmosphere through the filter. In addition to suppressing the exfoliated soot from returning to the ceramic honeycomb filter and ensuring that it is collected in the dust collection chamber, the backwashing efficiency of the ceramic honeycomb filter is also improved. has been further improved, and is also compact and compact.
It has become lighter and can be installed in cars,
Accordingly, it can be used in automobile exhaust systems, making it very useful and practical for automobiles.

As for the relationship between the invention and the specific examples, from the specific examples of the present invention described with reference to the drawings, various design modifications will be apparent to those who have ordinary knowledge in the technical field to which this invention pertains. Further, the contents of this invention are essential to the establishment of the invention to accomplish the task of the invention, and the technical essence of the invention which is the nature of the invention. and can be easily replaced by a form that is objectively recognized as incorporating it.

[Brief explanation of drawings]

The figure is a schematic diagram of the backwash type filter system of the present invention applied to the exhaust system of a diesel engine mounted on a truck. 1l, 12... Collection chamber, 13... Dust collection chamber, 14, 1
5... Filter population valve, 16, 17... Filter outlet valve, 18, 19... Trap population valve, 20, 21.
...Backwash valve.

Claims (2)

[Claims] (1) Two collection chambers equipped with ceramic honeycomb filters that are cleaned by reverse airflow and connected in parallel in the middle of the engine exhaust pipe, and a dust collection chamber connected to the entrance of the collection chambers. Backwash filter system including: (2) Two collection chambers equipped with ceramic honeycomb filters that are cleaned by reverse airflow and connected in parallel in the middle of the engine exhaust pipe, connected to the inlets of the collection chambers, and equipped with a filter and a dust collection chamber that is open to the atmosphere through a backwash filter system.