JPH05156922A - Backwasher of particulate filter - Google Patents

Abstract

PURPOSE:To remove particulates from a filter with yet more certainty by backwashing the filter in use of compressed intake pressure of a backwashing turbocharger, not canpressd air of a compressor, and regulating the extent of air blasting pressure according to a degree of loading in the filter. CONSTITUTION:A branch pipe 34 is set up after being branched off from an exhaust pipe 12 lying between an exhaust manifold 20 and a collector 13. In addition, there is provided a backwashing turbocharger 35 which has an exhaust turbine 35b being driven by energy of exhaust gas flowing into this branch pipe 34 and an intake compressor 35a being driven by this turbine. One end of a backwashing air pipe 36 is connected to an air discharge port of the intake compressor, and the other end is connected to a filter backwashing nozzle 18. A controller 30 selects a backwash valve 27 so as to make the exhaust gas flow into the branch pipe 34 at a time when an engine speed sensor 31 detects any lower speed than the specified one, closing a cutoff valve 27 and heating a heater 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forcibly blows compressed air from the exhaust gas downstream side to a filter in a collector for collecting particulates contained in engine exhaust gas,
The present invention relates to a device for removing collected particulates from a filter.

[0002]

2. Description of the Related Art Particulates, that is, soot and fine particles of hydrocarbons, sulfates, metals and the like adsorbed on soot are contained in the exhaust gas of an engine. And, in an operating state where the content increases, particulates are discharged to the outside, so an exhaust pipe of the engine is equipped with a collector with a heat-resistant filter for collecting particulates installed to purify the exhaust gas. ing. However, when the filter is used for a long period of time, particulates are deposited on the filter to cause the filter to be clogged, increasing its ventilation resistance and deteriorating the fuel consumption rate. In order to solve this point, a backwash type particulate trapping device is disclosed (for example, Japanese Patent Laid-Open No. 2-277914). In this collection device, a nozzle is provided in the exhaust pipe on the exhaust gas downstream side of the filter toward the filter, and a backwashing air pipe is piped from the air tank to this nozzle via a solenoid valve. Is provided with a shutoff valve, a particulate incinerator chamber is formed at the bottom of the collector, and a heater is provided in this incinerator chamber. When the filter is clogged with particulates, the shutoff valve is closed and the solenoid valve is opened to blow the compressed air in the air tank from the nozzle to the filter. Then, the particulates dropped from the filter into the incinerator are burned by the heat of the heater to regenerate the filter.

[0003]

However, since this backwashing device uses the compressed air of the air compressor, the capacity of the air compressor must be increased in accordance with the air consumption during the backwashing, which reduces the engine load. There was a problem that increased it. Further, even if the degree of clogging of the filter changes, the blowing pressure of the air is constant, so that the particulates cannot be reliably removed in some cases. An object of the present invention is to provide a backwash device for a particulate filter that can remove particulates from the filter without using compressed air of an air compressor. Another object of the present invention is to
It is an object of the present invention to provide a backwash device for a particulate filter that can more reliably remove particulates from the filter by adjusting the air blowing pressure when the degree of clogging of the filter and the blowing air pressure do not match.

[0004]

A structure of the present invention for achieving the above object will be described with reference to FIG. 1 corresponding to an embodiment. The backwashing device of the present invention is provided with a particulate collector 13 provided in the middle of an exhaust pipe 12 connected to an exhaust manifold 20 of an engine 10 and having a particulate filter 14 therein, and a bottom of the trap chamber 13. The formed particulate incineration chamber 16, a heater 17 provided in the incineration chamber 16, a nozzle 18 provided in the exhaust pipe 12 or the collector 13 on the exhaust gas downstream side of the filter 14 and directed to the filter 14, Exhaust manifold 20 and collector 13
A branch pipe 34 branched from the exhaust pipe 12 between
And a backwash turbocharger 35 having an exhaust turbine 35b driven by the energy of the exhaust gas flowing through the branch pipe 34 and an intake compressor 35a driven by the rotation of the turbine, and one end of an air discharge port of the intake compressor 35a. Is connected and the other end is connected to the nozzle 18, the backwash air pipe 36, the backwash valve 27 that can be switched so that the exhaust gas of the engine 10 flows to the branch pipe 34, the rotation sensor 31 of the engine 10, When the rotation sensor 31 detects a rotation speed lower than a predetermined speed, the backwash valve 27
Controller 30 for switching on and off and heating the heater 17
It is equipped with and.

[0005]

The controller 30 switches the backwash valve 27 when the rotation sensor 31 detects a rotation speed lower than a predetermined speed. As a result, the air compressed by the intake compressor 35a of the backwash turbocharger 35 is blown from the nozzle 18 to the filter 14, and the particulates fall into the incineration chamber 16. The dropped particulates are incinerated by the heater 17.

[0006]

An embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a diesel engine 1
Reference numeral 0 denotes an engine for a vehicle having a turbocharger 11, which has an exhaust pipe 12 connected to an exhaust manifold 20 thereof.
Exhaust turbine 11b of turbocharger 11 in the middle of
And a particulate collector 13 are provided. Inside the collector 13, a particulate filter 14 made of a porous heat-resistant ceramic material is provided. A particulate incineration chamber 16 is formed at the bottom of the collection chamber 13 below the filter, and the incineration chamber 16 is provided with a heater 17 for burning the particulates that have fallen from the filter and accumulated. In this example, as shown in detail in FIGS. 2 and 3, the inside of the collector 13 is divided into two filter chambers by the partition wall 13a, and the filters 14 and 14 are housed in the respective filter chambers. On the exhaust gas downstream side of the collector 13, two exhaust pipes 12, 12 communicating with the filters 14, 14 are connected, and the exhaust pipes 12, 12 are connected to the nozzles 18, 18 and the exhaust pipes on the exhaust gas downstream side thereof, respectively. Shut-off valves 26, 26 capable of shutting off are provided.

An air cleaner 15 is connected to an air inlet of the intake compressor 11a of the turbocharger 11 via an air pipe 15a. The intake compressor 11a and the intake manifold 19 of the engine 10 are connected by an intake pipe 21, and the compressor 11a is provided in the middle of the intake pipe 21.
An intercooler 22 that cools the compressed air discharged from is provided. A radiator 23 is provided between the front portion of the engine 10 and the intercooler 22. Exhaust turbine 11
A branch pipe 34 is piped from the exhaust pipe 12 between the b and the collector 13. An exhaust turbine 35b of a small backwash turbocharger 35 is provided in the middle of the branch pipe 34, and the end of the branch pipe 34 is inserted into the exhaust pipe 12 on the exhaust gas downstream side of the collector 13. The turbocharger 35 is provided with an intake compressor 35a driven by the rotation of the exhaust turbine 35b, and the air pipe 15a is connected to an air inlet of the compressor 35a via an air pipe 37. Further, one end of a backwashing air pipe 36 is connected to the air discharge port of the compressor 35a, and the other end of this air pipe 36 is branched and connected to the above-mentioned two nozzles 18, 18. A backwash valve 27 that can be switched so that the exhaust gas that has passed through the exhaust turbine 11b flows into the branch pipe 34 is provided at the branch point of the branch pipe 34, and the two nozzles 18 are provided at the branch point of the backwash air pipe 36. , 18 is provided with a switching valve 25 that can be switched so that air flows. The switching valve 25, the shutoff valve 26, and the backwash valve 27 are electromagnetic valves.

An exhaust gas pressure sensor 28 is provided in the exhaust pipe 12 on the upstream side of the exhaust gas of the particulate collector 13. Reference numeral 30 is a controller, and a pressure sensor 28, a rotation sensor 31 of the engine 10, and a vehicle speed sensor 32 are connected to its control input. The control output of the controller 30 is connected to the heater 17, the switching valve 25, the two shutoff valves 26, 26, and the backwash valve 27 described above.

The operation of the apparatus having such a configuration will be described.
The rotation sensor 31 has a predetermined speed (for example, idle speed)
When the higher rotation speed of the engine 10 is detected and the vehicle speed sensor 32 detects the vehicle traveling state, the controller 30 causes the switching valve 25, the shutoff valves 26, 26, the backwash valve 27.
And the heater 17 is not operated. As a result, the exhaust gas of the engine 10 passes through the filter 14,
In, the particulates contained in the exhaust gas are collected, and the purified exhaust gas is discharged from the exhaust gas outlet 12a. When the engine rotation speed is lower than the predetermined speed, the vehicle is stopped, and the pressure sensor 28 detects a pressure higher than the predetermined value, the controller 30 closes one of the two shutoff valves 26 for a predetermined time. After switching the switching valve 25 so that the air flows to the nozzle 18 having the shutoff valve 26 closed, the backwash valve 27 is opened.

As a result, the exhaust gas passing through the exhaust turbine 11b of the turbocharger 11 drives the exhaust turbine 35b of the backwash turbocharger 35. The intake compressor 35 a compresses new air introduced from the air cleaner 15 through the air pipe 37 to backwash the air pipe 36.
To discharge. As a result, the air is vigorously ejected from the nozzle 18, and the ejected air blows off the particulates adhering to the filter 14. The blown off particulates fall into the particulates incineration chamber 16 under their own weight. At the same time that the backwash valve 27 is opened, the controller 30 causes the heater 17 to generate heat for a predetermined time, burns the particulates that have fallen into the incinerator chamber 16 and regenerate the filter 14. The regeneration of the filter 14 is alternately performed by switching the switching valve 25 and operating the shutoff valve 26 alternately.

When the pressure of the exhaust gas in the exhaust pipe 12 becomes extremely high and the filter 14 is significantly clogged, the controller 30 uses the value of the pressure sensor 28 to check the backwash valve 27.
Increase the opening of. As a result, a large amount of exhaust gas is supplied to the exhaust turbine 35b, the rotation speed of the intake compressor 35a is increased, and higher-pressure backwash air is supplied to the nozzle 1.
It will start to jet from 8. If the degree of clogging is relatively small, on the contrary, the opening degree of the backwash valve 27 is reduced. Also,
Although a turbocharged engine is shown as the engine 10 in the above example, the present invention can also be applied to an engine not equipped with a turbocharger. In this case, the exhaust turbine 35b of the backwash turbocharger 35
Are driven directly by the exhaust gas emitted from the exhaust manifold.

[0012]

As described above, according to the present invention, the backwashing air is obtained by utilizing the exhaust gas energy with a small backwashing turbocharger, without using the air of the conventional air compressor. Therefore, it is not necessary to increase the capacity of the air compressor, and the engine load is not increased. In particular,
A pressure sensor that detects the pressure of the exhaust gas is installed in the exhaust pipe on the exhaust gas upstream side of the collector, and the controller controls the rotation speed of the exhaust turbine of the backwash turbocharger based on the detection value of this pressure sensor. For example, the blowing air pressure is adjusted according to the degree of clogging of the filter, and the particulates can be removed more reliably.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a backwash device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the collector.

3 is a cross-sectional view taken along the line AA of FIG.

[Explanation of Codes] 10 Engine 11 Turbocharger 11a Intake compressor 11b Exhaust turbine 12 Exhaust pipe 13 Particulate collector 14 Particulate filter 16 Particulate incinerator 17 Heater 18 Nozzle 20 Exhaust manifold 26 Shutoff valve 27 Backwash valve 28 Pressure Sensor 30 Controller 31 Rotation sensor 32 Vehicle speed sensor 34 Branch pipe 35 Backwash turbocharger 35a Intake compressor 35b Exhaust turbine 36 Backwash air pipe

Claims (2)

[Claims] 1. A particulate collector (1) provided in the middle of an exhaust pipe (12) connected to an exhaust manifold (20) of an engine (10) and having a particulate filter (14) therein.
3), a particulate incineration chamber (16) formed at the bottom of the collection chamber (13), a heater (17) provided in the incineration chamber (16), and exhaust gas downstream of the filter (14) Nozzle provided in the exhaust pipe (12) or collector (13) on the side and directed toward the filter (14)
(18), a branch pipe (34) branched from the exhaust pipe (12) between the exhaust manifold (20) and the collector (13), and flows to the branch pipe (34) A backwash turbocharger (35) having an exhaust turbine (35b) driven by the energy of exhaust gas and an intake compressor (35a) driven by the rotation of the turbine, and an air discharge port of the intake compressor (35a). An air pipe (3) for backwashing, one end of which is connected and the other end of which is connected to the nozzle (18).
6), a backwash valve (27) capable of switching the exhaust gas of the engine (10) so as to flow to the branch pipe (34), a rotation sensor (31) of the engine (10), and the rotation sensor ( 31) switches the backwash valve (27) when the rotational speed lower than a predetermined speed is detected and the heater (17)
A backwash device for a particulate filter, which is provided with a controller (30) for generating heat. 2. An exhaust pipe (12) upstream of the exhaust gas of the collector (13).
A pressure sensor (28) for detecting the pressure of exhaust gas is provided in the controller, and the controller (30) is configured to control the opening degree of the backwash valve (27) based on the detection value of the pressure sensor (28). The backwash device for a particulate filter according to claim 1.