JP2013015087A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently reduce NOx and particulates in an exhaust gas in a high temperature zone.SOLUTION: A first catalyst layer 21 comprising a silver based catalyst is formed on the whole inner surface of a flow-in holes 24c of a particulate filter 20, a collecting layer 23 capable of collecting the particulates 20 in the exhaust gas is formed on the whole inner surface of the first catalyst layer 21 and a second catalyst layer 22 comprising a copper based catalyst, an iron based catalyst or a vanadium based catalyst is formed on the whole inner surface of a flow out hole 20d of the filter 20. A first liquid injection nozzle capable of injecting a hydrocarbon based liquid toward the filter 20 is provided in the exhaust pipe of the exhaust gas upstream side of the filter 20. In a first hydrocarbon based liquid supply means, the liquid is supplied to the first liquid injection nozzle via a first liquid injection quantity control valve. A controller controls the first liquid injection control valve based on the detected output of a first temperature sensor for detecting the temperature of the exhaust gas related to the filter 20.

Description

  The present invention relates to an apparatus for purifying exhaust gas by reducing nitrogen oxide (hereinafter referred to as NOx) contained in exhaust gas of a diesel engine.

  Conventionally, as this type of exhaust gas purification device, a particulate filter capable of temporarily collecting particulate matter in exhaust gas and carrying an ammonia selective reduction catalyst is provided in the exhaust passage of the internal combustion engine, and the urea supply means is the particulate An exhaust purification device for an internal combustion engine configured to supply urea from upstream of a filter is disclosed (for example, see Patent Document 1). In this exhaust purification apparatus, the ammonia selective reduction catalyst is at least one of titania-vanadium, zeolite, chromium, manganese, molybdenum, and tungsten. The ammonia selective reduction catalyst is supported more in the partition wall than in the partition wall surface of the particulate filter.

  In the exhaust gas purification apparatus for an internal combustion engine configured as described above, particulate matter contained in the exhaust gas is collected in the particulate filter when the exhaust gas passes through the particulate filter, and NOx in the exhaust gas is converted into an ammonia selective reduction catalyst. Reduced by Here, by supporting the ammonia selective reduction catalyst on the particulate filter, the contact area between the ammonia selective reduction catalyst and the exhaust gas is widened, so the chance of NOx in the exhaust gas contacting the ammonia reduction catalyst increases. As a result, the NOx reduction rate by the ammonia reduction catalyst can be improved. Therefore, removal of particulate matter in exhaust gas and purification of NOx can be performed with one filter.

  Also, some of the multiple channels in the honeycomb array are plugged at the upstream end, channels that are not plugged at the upstream end are plugged at the downstream end, and substantially gas-free at the upstream end of the channels plugged at the downstream end. There is disclosed a filter in which an oxidation catalyst is formed on a permeable zone and a gas permeable filter zone for capturing soot is formed downstream of the oxidation catalyst (see, for example, Patent Document 2). In this filter, the oxidation catalyst includes a platinum group metal (PGM), preferably one or both of Pt or Pd, and the filter zone includes a catalyst that promotes soot combustion. The filter is disposed in the exhaust mechanism of the combustion engine.

In the filter configured in this manner, first, the exhaust gas containing NO is passed over the oxidation catalyst without filtering, so that the oxidation catalyst converts NO in the exhaust gas into NO ₂ at a temperature of less than 400 ° C. Thereafter, the soot on the filter is continuously burned using the exhaust gas containing NO ₂ .

JP 2004-60494 A (claim 1, claim 4, paragraph [0012], FIG. 1) JP-T-2005-500147 (Claim 1, Claim 6, Claim 25)

However, since the exhaust purification device for an internal combustion engine disclosed in Patent Document 1 uses urea as a reducing agent, a urea water tank that stores urea water in the vehicle when the exhaust purification device is mounted on a vehicle. There is a problem that the operation of replenishing the urea water tank with the urea water is relatively troublesome. Moreover, in the filter shown in the above-mentioned conventional patent document 2, since the oxidation catalyst is gas-impermeable, the area of the gas-permeable filter zone is narrowed, and an attempt is made to secure the area of the gas-permeable filter zone. Then, there existed a problem which a filter will enlarge. Further, in the conventional filter disclosed in Patent Document 2, since an oxidation catalyst is formed at the upstream end of the channel plugged at the downstream end, if exhaust gas containing particulates flows into the filter channel, the particulates Has accumulated on the oxidation catalyst, which hinders the function of the oxidation catalyst to convert NO in the exhaust gas into NO ₂ .

  A first object of the present invention is to provide an exhaust gas purifying apparatus capable of efficiently reducing NOx and particulates in a high temperature range of exhaust gas. A second object of the present invention is to provide an exhaust gas purifying apparatus in which a hydrocarbon-based liquid such as a fuel that is relatively easy to handle can be used as a reducing agent instead of urea water. A third object of the present invention is to provide an exhaust gas purifying apparatus that does not increase the size of a particulate filter and can prevent the accumulation of particulates on a catalyst layer. A fourth object of the present invention is to provide an exhaust gas purifying apparatus capable of efficiently reducing NOx and particulates over a wide temperature range from a low temperature range to a high temperature range of the exhaust gas.

  As shown in FIGS. 1 and 2, the first aspect of the present invention is that a particulate filter 20 for collecting particulates in exhaust gas is provided in the exhaust pipe 16 of the engine 11, and the particulate filter 20 is porous. A plurality of through holes 24b partitioned by a quality partition wall 24a have a carrier 24 formed in parallel with each other, and the inflow holes 24c are sealed by alternately sealing the adjacent outlet portions and inlet portions of the plurality of through holes 24b. In the exhaust gas purifying device in which the exhaust hole 24d and the outflow hole 24d are respectively formed, the first catalyst layer 21 made of a silver-based catalyst is formed on all or part of the inner surface of the inflow hole 24c so that the exhaust gas can pass therethrough. A collecting layer 23 capable of collecting particulates in the exhaust gas is formed on the entire inner surface of the exhaust gas 21 so that the exhaust gas can pass therethrough, and a copper-based catalyst is formed on all or a part of the inner surface of the outflow hole 24d. A second catalyst layer 22 made of an iron-based catalyst or a vanadium-based catalyst is formed in a state in which exhaust gas can pass, and is provided in the exhaust pipe 16 on the exhaust gas upstream side of the particulate filter 20 and is directed toward the particulate filter 20. A first liquid injection nozzle 31 capable of injecting the liquid 32; a first hydrocarbon-based liquid supply means 41 for supplying the liquid 32 to the first liquid injection nozzle 31 via a first liquid injection amount adjustment valve 44; A first temperature sensor 81 for detecting the temperature of exhaust gas related to the filter 20 and a controller 86 for controlling the first liquid injection amount adjusting valve 44 based on the detection output of the first temperature sensor 81 are provided. To do.

  As shown in FIG. 3, the second aspect of the present invention is that a particulate filter 100 for collecting particulates in exhaust gas is provided in an exhaust pipe of an engine, and the particulate filter 100 is a porous partition wall 101a. In an exhaust gas purification apparatus having a carrier 101 in which a plurality of partitioned through-holes 101b are formed in parallel to each other, the inflow / outflow holes 101c and the outflow holes 101d are formed by sealing every other inlet portion of the plurality of through-holes 101b. A first catalyst layer 21 made of a silver-based catalyst is formed in a state where exhaust gas can pass over all or part of the inner surface of the inflow / outflow hole 101c, and the entire inner surface of the first catalyst layer 21 contains exhaust gas in the exhaust gas. A collection layer 23 capable of collecting particulates is formed in a state in which exhaust gas can pass, and a copper-based catalyst or iron is formed on all or part of the inner surface of the outflow hole 101d. A second catalyst layer 22 made of a catalyst or a vanadium catalyst is formed in a state in which exhaust gas can pass, and is provided in an exhaust pipe upstream of the particulate filter 100 and can inject hydrocarbon-based liquid toward the particulate filter. First liquid injection nozzle, first hydrocarbon liquid supply means for supplying liquid to the first liquid injection nozzle via the first liquid injection amount adjustment valve, and temperature of exhaust gas related to the particulate filter 100 are detected. And a controller for controlling the first liquid injection amount adjusting valve based on a detection output of the first temperature sensor.

  The third aspect of the present invention is an invention based on the first aspect, and further, as shown in FIG. 4, the coating area and coating position on the inner surface of the inflow hole 24c of the first catalyst layer 121, and the second catalyst. The coating area and the coating position on the inner surface of the outflow hole 24d of the layer 22 are configured to be set based on one or both of the pressure loss of the particulate filter 120 and the required reduction rate of NOx. To do.

  The fourth aspect of the present invention is an invention based on the second aspect, and as shown in FIG. 5, the coating area and the coating position on the inner surface of the inflow / outflow hole 101c of the first catalyst layer 121, and the second The coating area and the coating position on the inner surface of the outflow hole 101d of the catalyst layer 122 are configured to be set based on one or both of the pressure loss of the particulate filter 140 and the required reduction rate of NOx. And

  The fifth aspect of the present invention is an invention based on the first or second aspect, and further, as shown in FIG. 2, an oxidation function and NOx are added to the exhaust pipe 16 on the exhaust gas upstream side of the first liquid injection nozzle 31. The first oxidation-reduction catalyst 51 having the reduction function is provided, and a second hydrocarbon-based liquid 32 can be injected toward the first oxidation-reduction catalyst 51 into the exhaust pipe 16 upstream of the first oxidation-reduction catalyst 51. A liquid injection nozzle 52 is provided, and a second hydrocarbon-based liquid supply means 62 that supplies the liquid 32 to the second liquid injection nozzle 52 via the second liquid injection amount adjustment valve 64 is connected to the second liquid injection nozzle 52. The temperature of the exhaust gas related to the first redox catalyst 51 is detected by the second temperature sensor 82, and the controller 86 controls the second liquid injection amount adjustment valve 64 based on the detection output of the second temperature sensor 82. Composed Characterized in that was.

  The sixth aspect of the present invention is an invention based on the first or second aspect, and further, as shown in FIG. 1, the first catalyst layer 21 is formed on the carrier 24 of the particulate filter 20 with silver zeolite or silver alumina. The second catalyst layer 22 is formed by coating the carrier 24 of the particulate filter 20 with copper zeolite, iron zeolite or vanadium oxide.

  The seventh aspect of the present invention is an invention based on the first or second aspect, and as shown in FIG. 2, the second redox catalyst 72 is provided in the exhaust pipe 16 on the exhaust gas downstream side of the particulate filter 20. And the second redox catalyst 72 oxidizes the hydrocarbon liquid 32 when the hydrocarbon liquid 32 is discharged from the particulate filter 20 and ammonia is discharged from the particulate filter 20. It is characterized by having an oxidation function for oxidizing ammonia when it is discharged and a reduction function for reducing NOx when NOx is exhausted from the particulate filter 20.

  In the exhaust gas purifying apparatus according to the first aspect of the present invention, when the hydrocarbon-based liquid is injected from the first liquid injection nozzle in the high-temperature region of the exhaust gas, the hydrocarbon-based liquid, together with the exhaust gas of the engine, enters the inlet portion of the particulate filter. When the particulates in the exhaust gas are collected in the collection layer and the exhaust gas from which the particulates are removed flows into the silver-based first catalyst layer together with the hydrocarbon-based liquid, the first When ammonia is generated on the catalyst layer and the exhaust gas containing ammonia flows into the copper-based, iron-based, or vanadium-based second catalyst layer, ammonia and NOx react on the second catalyst layer to reduce NOx. The reaction and the oxidation reaction of ammonia are promoted. As a result, NOx and particulates in the exhaust gas can be efficiently reduced in the high temperature range of the exhaust gas.

Further, when mounted on a vehicle, it is necessary to provide a urea water tank for storing urea water as a reducing agent separately from the fuel tank, and the exhaust of a conventional internal combustion engine in which the operation of replenishing urea water to the urea water tank is relatively troublesome. Compared with the purification device, since the present invention uses a hydrocarbon-based liquid such as light oil as the reducing agent, the light oil stored in the fuel tank can be used when mounted on a vehicle. There is no need to provide a tank, and handling of the reducing agent is relatively easy. In addition, since the oxidation catalyst is gas impermeable, the area of the gas permeable filter zone is narrowed, and when trying to secure the area of the gas permeable filter zone, the filter becomes larger than the conventional filter. In the present invention, since the collection layer, the first catalyst layer, and the second catalyst layer are formed in a state in which the exhaust gas can pass, it is not necessary to increase the size of the particulate filter. Furthermore, since an oxidation catalyst is formed at the upstream end of the channel plugged at the downstream end, when exhaust gas containing particulates flows into the channel of the filter, the particulates accumulate on the oxidation catalyst, and NO in the exhaust gas is reduced. Compared with the conventional filter that may impede the function of the oxidation catalyst that converts to NO ₂ , in the present invention, before the exhaust gas flows into the first and second catalyst layers, the particulate matter in the exhaust gas is collected in the collection layer. Since the curate is collected, the accumulation of particulates on the first and second catalyst layers can be prevented.

  In the exhaust gas purification apparatus according to the second aspect of the present invention, the man-hour for sealing the outlet portion of the outflow hole with the sealing member is necessary, but the man-hour for sealing the inlet portion of the inflow / outflow hole with the sealing member is unnecessary. Therefore, the number of manufacturing steps for the particulate filter can be reduced. As a result, the manufacturing cost of the particulate filter can be reduced. In addition, the pressure on the outlet side of the particulate filter is lower than that on the inlet side, so the exhaust gas that enters from the inlet and outlet holes enters the inlet and outlet holes and enters through the porous partition. More exhaust gas exits from the outlet of the outflow hole. As a result, similarly to the above, NOx and particulates in the exhaust gas can be efficiently reduced in the high temperature range of the exhaust gas.

  In the exhaust gas purifying apparatus according to the third and fourth aspects of the present invention, the amount of silver used for the first catalyst layer and the amount of copper, iron or vanadium used for the second catalyst layer can be reduced. As a result, the manufacturing cost of the particulate filter can be reduced.

  In the exhaust gas purifying apparatus according to the fifth aspect of the present invention, when the hydrocarbon-based liquid is injected from the second liquid injection nozzle in the low temperature range of the exhaust gas, the first redox catalyst that exhibits the reduction performance of NOx in the exhaust gas is produced. Since it reacts with NOx in the exhaust gas and NOx is rapidly reduced, NOx can be efficiently reduced in the low temperature region of the exhaust gas. On the other hand, when the hydrocarbon-based liquid is injected from the first liquid injection nozzle in the high temperature region of the exhaust gas, the hydrocarbon-based liquid flows into the inflow hole from the inlet portion of the particulate filter together with the exhaust gas of the engine, and the trapping layer When particulates in the exhaust gas are collected in the exhaust gas and the exhaust gas from which the particulates have been removed flows into the silver-based first catalyst layer together with the hydrocarbon-based liquid, ammonia is generated on the first catalyst layer. When exhaust gas containing nitrogen flows into the copper-based, iron-based or vanadium-based second catalyst layer, ammonia and NOx react on the second catalyst layer, and the NOx reduction reaction and ammonia oxidation reaction are promoted. . As a result, NOx and particulates can be efficiently reduced over a wide temperature range from a low temperature range to a high temperature range of the exhaust gas.

  In the exhaust gas purifying apparatus according to the seventh aspect of the present invention, when the hydrocarbon liquid is discharged from the particulate filter, the second redox catalyst oxidizes the hydrocarbon liquid and ammonia is discharged from the particulate filter. When this is done, the second redox catalyst oxidizes this ammonia, and when NOx is discharged from the particulate filter, the second redox catalyst reduces this NOx. As a result, it is possible to prevent the hydrocarbon liquid, ammonia and NOx from being discharged into the atmosphere.

It is a section lineblock diagram of the particulate filter of a 1st embodiment of the present invention. It is a block diagram which shows the exhaust gas purification apparatus containing the particulate filter. It is a section lineblock diagram of the particulate filter of a 2nd embodiment of the present invention. It is a section lineblock diagram of the particulate filter of a 3rd embodiment of the present invention. It is a section lineblock diagram of the particulate filter of a 4th embodiment of the present invention. It is a figure which shows the change of NOx reduction rate when the model gas imitating exhaust gas is made to flow into the exhaust gas purification apparatus of Example 1 and Comparative Example 1, and this model gas temperature is changed. It is a graph showing changes in conversion to NH ₃ in the NOx in the first catalyst layer with respect to a change in the model gas temperature flowing model gases to the first catalyst layer of Example 1. It is a figure which shows the total NOx reduction rate when attaching the exhaust gas purification apparatus of Example 1 and Comparative Example 1 to the exhaust pipe of the diesel engine of the same type, respectively, and changing exhaust gas temperature.

  Next, an embodiment for carrying out the present invention will be described with reference to the drawings.

<First Embodiment>
As shown in FIG. 2, an intake pipe 13 is connected to the intake port of the diesel engine 11 via an intake manifold 12, and an exhaust pipe 16 is connected to the exhaust port via an exhaust manifold 14. The intake pipe 13 is provided with a compressor housing 17a of the turbocharger 17 and an intercooler 18 for cooling the intake air compressed by the turbocharger 17, and the exhaust pipe 16 is provided with a turbine of the turbocharger 17. A housing 17b is provided. Compressor rotor blades (not shown) are rotatably accommodated in the compressor housing 17a, and turbine rotor blades (not shown) are rotatably accommodated in the turbine housing 17b. The compressor rotor blades and the turbine rotor blades are connected by a shaft (not shown), and the compressor rotor blades are rotated via the turbine rotor blades and the shaft by the energy of the exhaust gas discharged from the engine 11, and the compressor rotor blades are rotated. Thus, the intake air in the intake pipe 13 is compressed.

  A particulate filter 20 that collects particulates in the exhaust gas is provided in the middle of the exhaust pipe 16. The particulate filter 20 is accommodated in a case 19 having a larger diameter than the exhaust pipe 16. As shown in FIG. 1, the particulate filter 20 includes a honeycomb-shaped carrier in which a plurality of through-holes 24b partitioned by porous partition walls 24a made of ceramic such as cordierite and silicon carbide are formed in parallel to each other. 24. An inflow hole 24c and an outflow hole 24d are formed by alternately sealing the outlet portions and the inlet portions adjacent to each other of the plurality of through holes 24b. That is, the inflow hole 24c is formed by sealing the outlet side of the plurality of through holes 24b with the sealing member 24e and opening the inlet side, and the inlet side of the plurality of through holes 24b by the sealing member 24e. The outlet hole 24d is formed by sealing and opening the outlet side. Here, the outlet portion of the through hole 24b refers to a portion having a depth including the outlet sealed by the sealing member 24e of the through hole 24b. That is, the depth of the outlet portion of the through hole 24b changes according to the thickness of the sealing member 24e. When the sealing member 24e is thick, the depth is deep, and when the sealing member 24e is thin, Its depth becomes shallower. Moreover, the inlet part of the through-hole 24b means the part of the inlet sealed with the sealing member 24e of the through-hole 24b. That is, the depth of the inlet portion of the through hole 24b varies depending on the thickness of the sealing member 24e. When the sealing member 24e is thick, the depth is deep, and when the sealing member 24e is thin, Its depth becomes shallower.

  A first catalyst layer 21 made of a silver-based catalyst is formed on the entire surface (the entire inner surface) of the inflow hole 24c of the particulate filter 20 in a state in which exhaust gas can pass (FIG. 1). A collection layer 23 capable of collecting particulates in the exhaust gas is formed on the entire surface of the first catalyst layer 21 (the entire inner surface) in a state in which the exhaust gas can pass. Furthermore, a second catalyst layer 22 made of a copper-based catalyst, an iron-based catalyst, or a vanadium-based catalyst is formed on the entire surface of the outflow hole 24d (the entire inner surface) so that the exhaust gas can pass therethrough. The first catalyst layer 21 is formed by coating the carrier 24 of the filter 20 with silver zeolite or silver alumina. Specifically, the first catalyst layer 21 made of silver zeolite is formed by coating the carrier 24 of the filter 20 with a slurry containing zeolite powder obtained by ion exchange of silver. The first catalyst layer 21 made of silver alumina is formed by coating the carrier 24 of the filter 20 with a slurry containing γ-alumina powder or θ-alumina powder supporting silver.

  The collection layer 23 is formed by coating the surface of the first catalyst layer 21 of the carrier 24 of the filter 20 with a slurry containing γ-alumina powder or θ-alumina powder (FIG. 1). The second catalyst layer 22 is formed by coating the carrier 24 of the filter 20 with copper zeolite, iron zeolite, or vanadium oxide. Specifically, the second catalyst layer 22 made of copper zeolite is formed by coating the carrier 24 of the filter 20 with a slurry containing zeolite powder obtained by ion exchange of copper. The second catalyst layer 22 made of iron zeolite is formed by coating the carrier 24 of the filter 20 with a slurry containing zeolite powder obtained by ion exchange of iron. Furthermore, the second catalyst layer 22 made of vanadium-based oxide contains a slurry containing only vanadium oxide powder or a composite oxide powder containing titanium oxide and tungsten oxide in vanadium oxide. Each of the carriers 24 is formed by coating.

  On the other hand, the case 19 on the exhaust gas upstream side of the particulate filter 20 is provided with a first liquid injection nozzle 31 capable of injecting a hydrocarbon-based liquid 32 toward the filter 20 (FIG. 2). A first hydrocarbon liquid supply means 41 is connected to the first liquid injection nozzle 31. The first hydrocarbon-based liquid supply means 41 includes a first liquid supply pipe 42 having one end connected to the first liquid injection nozzle 31, and the other end of the first liquid supply pipe 42 to store the liquid 32. A fuel tank 43 and a first liquid injection amount adjustment valve 44 that adjusts the injection amount of the liquid 32 injected from the first liquid injection nozzle 31 are provided. The hydrocarbon liquid 32 is a fuel such as light oil in this embodiment. The first liquid injection amount adjustment valve 44 is provided in the first liquid supply pipe 42 and adjusts the supply pressure of the liquid 32 to the first liquid injection nozzle 31, and the first liquid injection nozzle 31. And a first nozzle opening / closing valve 46 that opens and closes the first liquid injection nozzle 31. Further, a pump 47 capable of supplying the liquid 32 in the fuel tank 43 to the first liquid injection nozzle 31 is provided in the first liquid supply pipe 42 between the first pressure regulating valve 45 and the fuel tank 43.

  The first pressure regulating valve 45 is a three-way valve having first to third ports 45a to 45c (FIG. 2). The first port 45a is connected to the discharge port of the pump 47 via the first liquid supply pipe 42, the second port 45b is connected to the first liquid injection nozzle 31 via the first nozzle opening / closing valve 46, and the third port 45 c is connected to the fuel tank 43 via the first return pipe 48. When the first pressure regulating valve 45 is turned on, the liquid pumped by the pump 47 flows into the first pressure regulating valve 45 from the first port 45a and is adjusted to a predetermined pressure by the first pressure regulating valve 45. It is pumped from the second port 45 b to the first liquid jet nozzle 31. When the first pressure adjustment valve 45 is turned off, the liquid 32 pumped by the pump 47 flows into the first pressure adjustment valve 45 from the first port 45a, and then passes through the first return pipe 48 from the third port 45c. Returned to the tank 43.

  On the other hand, the case 19 on the exhaust gas upstream side of the first liquid injection nozzle 31 is provided with a first oxidation-reduction catalyst 51 having an oxidation function and a NOx reduction function (FIG. 2). The first oxidation-reduction catalyst 51 is a monolithic catalyst, and is configured by coating a cordierite honeycomb carrier with a noble metal zeolite such as platinum or a noble metal alumina such as platinum. Specifically, the first redox catalyst 51 made of a noble metal zeolite such as platinum is configured by coating a honeycomb carrier with a slurry containing zeolite powder obtained by ion exchange of a noble metal such as platinum. The first redox catalyst 51 made of noble metal alumina such as platinum is formed by coating a honeycomb carrier with a slurry containing γ-alumina powder or θ-alumina powder supporting a noble metal such as platinum.

  The case 19 on the exhaust gas upstream side of the first oxidation-reduction catalyst 51 is provided with a second liquid injection nozzle 52 capable of injecting the hydrocarbon-based liquid 32 toward the first oxidation-reduction catalyst 51 (FIG. 2). A second hydrocarbon-based liquid supply means 62 is connected to the second liquid injection nozzle 52. The second hydrocarbon-based liquid supply means 62 includes a second liquid supply pipe 63 having one end connected to the second liquid injection nozzle 52 and the other end connected to the vicinity of the discharge port of the pump 47 of the first liquid supply pipe 42, A second liquid injection amount adjusting valve 64 for adjusting the injection amount of the liquid 32 injected from the two liquid injection nozzles 52, the fuel tank 43, and the pump 47. The fuel tank 43 and the pump 47 of the first hydrocarbon liquid supply means 41 are used as components of the second hydrocarbon liquid supply means 62. That is, the fuel tank 43 and the pump 47 are common parts of the first and second hydrocarbon-based liquid supply means 41 and 62. The second liquid injection amount adjustment valve 64 is provided in the second liquid supply pipe 63 to adjust the supply pressure of the liquid 32 to the second liquid injection nozzle 52, and the second liquid injection nozzle 52. And a second nozzle opening / closing valve 66 that opens and closes the second liquid jet nozzle 52.

  The second pressure regulating valve 65 is a three-way valve having first to third ports 65a to 65c (FIG. 2). The first port 65 a is connected to the discharge port of the pump 47 via the second liquid supply pipe 63 and the first liquid supply pipe 42, and the second port 65 b is connected to the second liquid injection nozzle 52 via the second nozzle opening / closing valve 66. The third port 65 c is connected to the fuel tank 43 via the second return pipe 67. When the second pressure regulating valve 65 is turned on, the liquid 32 pumped by the pump 47 flows into the second pressure regulating valve 65 from the first port 65a and is adjusted to a predetermined pressure by the second pressure regulating valve 65. The second liquid jet nozzle 52 is pumped from the second port 65b. When the second pressure regulating valve 65 is turned off, the liquid 32 pumped by the pump 47 flows from the first port 65a into the second pressure regulating valve 65 and then passes through the second return pipe 67 from the third port 65c. Returned to the tank 43.

  On the other hand, the second oxidation-reduction catalyst 72 is provided in the case 19 downstream of the exhaust gas from the particulate filter 20 (FIG. 2). The second redox catalyst 72 is configured in the same manner as the first redox catalyst 51. That is, the second oxidation-reduction catalyst 72 is a monolith catalyst, and is configured by coating a cordierite honeycomb carrier with a noble metal zeolite such as platinum or a noble metal alumina such as platinum. Specifically, the second oxidation-reduction catalyst 72 made of a noble metal zeolite such as platinum is configured by coating a honeycomb carrier with a slurry containing zeolite powder obtained by ion exchange of a noble metal such as platinum. The second oxidation-reduction catalyst 72 made of noble metal alumina such as platinum is configured by coating a honeycomb carrier with a slurry containing γ-alumina powder or θ-alumina powder supporting a noble metal such as platinum. The second redox catalyst 72 oxidizes the hydrocarbon liquid 32 when the hydrocarbon liquid 32 is discharged from the filter 20 and oxidizes the ammonia when ammonia is discharged from the filter 20. And an oxidation function for reducing NOx when NOx is exhausted from the filter 20.

  The case 19 on the exhaust gas upstream side of the particulate filter 20 and on the exhaust gas downstream side of the first oxidation-reduction catalyst 51 has a temperature of exhaust gas related to the filter 20, in this embodiment, the exhaust gas immediately before flowing through the filter 20. A first temperature sensor 81 for detecting temperature is provided (FIG. 2). A second temperature sensor 82 that detects the temperature of the exhaust gas related to the first oxidation-reduction catalyst 51 is provided in the exhaust pipe 16 upstream of the first oxidation-reduction catalyst 51. Further, the rotation speed of the engine 11 is detected by the rotation sensor 83, and the load of the engine 11 is detected by the load sensor 84. The detection outputs of the first temperature sensor 81, the second temperature sensor 82, the rotation sensor 83, and the load sensor 84 are connected to the control input of the controller 86. The control output of the controller 86 is the pump 47, the first pressure regulating valve 45, the first The first nozzle opening / closing valve 46, the second pressure regulating valve 65, and the second nozzle opening / closing valve 66 are connected to each other. The controller 86 is provided with a memory 87. The memory 87 stores the pressure of the first pressure regulating valve 45 according to the engine speed, the engine load, the exhaust gas temperature at the filter inlet (just before flowing through the filter 20), the number of times of opening and closing the first nozzle opening / closing valve 46, and the pump 47. The presence / absence of the operation is stored in advance. Further, the memory 87 stores the pressure of the second pressure regulating valve 65 according to the engine speed, the engine load, the exhaust gas temperature at the first oxidation-reduction catalyst inlet (immediately before flowing through the first oxidation-reduction catalyst 51), the second nozzle opening / closing The number of opening / closing of the valve 66 and the presence / absence of operation of the pump 47 are stored in advance.

  In the first embodiment, the first temperature sensor is provided in the case on the exhaust gas upstream side of the filter and on the exhaust gas downstream side of the first oxidation-reduction catalyst, but the second oxidation is on the exhaust gas downstream side of the filter. A first temperature sensor is provided in a case upstream of the reduction catalyst from the exhaust gas, or a case of the exhaust gas upstream of the filter and downstream of the first oxidation-reduction catalyst, and a second oxidation of the exhaust gas downstream of the filter and the second oxidation. A first temperature sensor may be provided in each case on the exhaust gas upstream side of the reduction catalyst. When a first temperature sensor is provided in the case downstream of the exhaust gas from the filter and upstream of the second redox catalyst, the temperature of the exhaust gas at the filter outlet (immediately after flowing through the filter) is detected by the first temperature sensor. Is done. A first temperature sensor is provided in each case upstream of the filter and upstream of the first oxidation-reduction catalyst, and in a case downstream of the filter and downstream of the exhaust gas and upstream of the second oxidation-reduction catalyst. In other words, when the first temperature sensor is provided immediately before and after the filter, the exhaust gas temperature at the filter inlet (immediately before flowing through the filter) and the exhaust gas temperature at the filter outlet (immediately after flowing through the filter) are detected. Therefore, the temperature of the exhaust gas flowing through the filter can be detected by calculating the average value of both temperatures.

  In the first embodiment, the second temperature sensor is provided in the exhaust pipe upstream of the first oxidation-reduction catalyst, but is located downstream of the first oxidation-reduction catalyst and upstream of the filter. A second temperature sensor is provided in the case, or a second temperature sensor is provided in the exhaust pipe upstream of the first oxidation-reduction catalyst and on the exhaust gas downstream of the first oxidation-reduction catalyst and on the exhaust gas upstream of the filter. May be provided. When a second temperature sensor is provided in the case downstream of the first oxidation-reduction catalyst and upstream of the filter, the second temperature sensor causes the first oxidation-reduction catalyst outlet (the first oxidation-reduction catalyst to flow). The temperature of the exhaust gas immediately after) is detected. Further, when the second temperature sensor is provided in the exhaust pipe upstream of the first redox catalyst and in the case downstream of the first redox catalyst and downstream of the exhaust gas and upstream of the filter, that is, the first oxidation. When the second temperature sensor is provided immediately before and after the reduction catalyst, the exhaust gas temperature at the first oxidation-reduction catalyst inlet (immediately before flowing through the first oxidation-reduction catalyst) and the first oxidation-reduction catalyst outlet (first oxidation-reduction catalyst are installed). Therefore, the temperature of the exhaust gas flowing through the first oxidation-reduction catalyst can be detected by calculating the average value of the two temperatures.

  The operation of the exhaust gas purification apparatus configured as described above will be described. When the exhaust gas temperature is extremely low, such as immediately after the engine 11 is started, less than 180 ° C., the exhaust gas temperature on the inlet side of the first oxidation-reduction catalyst 51 is too low, and the first oxidation-reduction catalyst 51 can almost reduce NOx. In addition, since the exhaust gas temperature on the inlet side of the particulate filter 20 is too low and almost no NOx can be reduced by the first and second catalyst layers 21 and 22 of the filter 20, the controller 86 includes the first temperature sensor 81 and the second temperature sensor 81. Based on the detection outputs of the temperature sensor 82, the rotation sensor 83, and the load sensor 84, the pump 47 is deactivated, and the first pressure regulating valve 45, the first nozzle opening / closing valve 46, the second pressure regulating valve 65, and the second nozzle. The on-off valve 66 is turned off to keep the hydrocarbon liquid 32 from being injected from the first and second liquid injection nozzles 31 and 52.

  When the exhaust gas temperature rises to a low temperature range (for example, 180 to 300 ° C.), the controller 86 determines the pump 47 based on the detection outputs of the first temperature sensor 81, the second temperature sensor 82, the rotation sensor 83, and the load sensor 84. , The second pressure regulating valve 65 is turned on, and the second nozzle opening / closing valve 66 is repeatedly turned on and off, so that the hydrocarbon liquid 32 is intermittently ejected from the second liquid ejection nozzle 52. The hydrocarbon liquid 32 injected from the second liquid injection nozzle 52 is gasified and flows into the first redox catalyst 51. Since the first oxidation-reduction catalyst 51 greatly exhibits the NOx reduction function in the low temperature range of the exhaust gas, the gasified hydrocarbon liquid 32 reacts with NOx in the exhaust gas on the first oxidation-reduction catalyst 51, Most NOx is rapidly reduced. NOx that has passed through the first oxidation-reduction catalyst 51 flows into the filter 20 together with the exhaust gas, and particulates in the exhaust gas are collected by the collection layer 23. The exhaust gas from which the particulates have been removed is discharged from the filter 20 and flows into the second oxidation-reduction catalyst 72. The second oxidation-reduction catalyst 72, like the first oxidation-reduction catalyst 51, greatly expresses the NOx reduction function in the low temperature range of the exhaust gas, and is therefore injected from the first liquid injection nozzle 31 and the first oxidation-reduction catalyst. The hydrocarbon liquid 32 that has passed through 51 and the filter 20 reacts with NOx in the exhaust gas on the second oxidation-reduction catalyst 72, and NOx is rapidly reduced. As a result, NOx in the exhaust gas is efficiently reduced in the low temperature region of the exhaust gas together with the particulates.

When the exhaust gas temperature further rises and reaches a high temperature range (for example, 300 to 600 ° C.), the controller 86 determines the first based on the detection outputs of the first temperature sensor 81, the second temperature sensor 82, the rotation sensor 83, and the load sensor 84. The 1st pressure regulating valve 45, the 1st nozzle on-off valve 46, the 2nd pressure regulating valve 65, and the 2nd nozzle on-off valve 66 are controlled, and the hydrocarbon liquid 32 is intermittently supplied from the 1st and 2nd liquid injection nozzles 31 and 52. Inject. When the hydrocarbon liquid 32 injected from the second liquid injection nozzle 52 is gasified and flows into the first oxidation-reduction catalyst 51, the catalyst 51 functions as an oxidation catalyst, and the hydrocarbon liquid 32 is burned by the catalyst 51. As a result, the exhaust gas temperature increases. The exhaust gas whose temperature has risen flows into the filter 20 together with the hydrocarbon liquid 32 gasified by being injected from the first liquid injection nozzle 31, and the particulates in the exhaust gas are collected by the collection layer 23. When the exhaust gas from which the particulates have been removed flows into the silver-based first catalyst layer 21, ammonia is generated on the catalyst layer 21. When the exhaust gas containing ammonia flows into the copper-based, iron-based or vanadium-based second catalyst layer 22, as shown in the following formulas (1) to (3), NOx (NO and NO ₂₎ is reduced to N ₂ by reaction with ammonia.

NO + NO ₂ + 2NH ₃ → 2N ₂ + 3H ₂ O (1)
4NO + 4NH ₃ + O ₂ → 4N ₂ + 6H ₂ O (2)
6NO ₂ + 8NH ₃ → 7N ₂ + 12H ₂ O (3)
As a result, NOx in the exhaust gas is efficiently reduced in the exhaust gas at high temperatures. When the temperature of the exhaust gas flowing into the filter 20 exceeds 600 ° C., the particulates deposited on the collection layer 23 of the filter 20 are burned and removed by the high temperature exhaust gas. Further, when excess hydrocarbon liquid 32 and excess ammonia are discharged from the second catalyst layer 22, excess hydrocarbon liquid 32 and ammonia are oxidized by the second oxidation-reduction catalyst 72. It is not discharged inside. Therefore, NOx and particulates can be efficiently reduced over a wide temperature range from a low temperature range to a high temperature range.

<Second Embodiment>
FIG. 3 shows a second embodiment of the present invention. 3, the same reference numerals as those in FIG. 1 denote the same components. In this embodiment, the inflow / outflow holes 101c and the outflow holes 101d are formed by sealing every other inlet of the plurality of through holes 101b partitioned by the porous partition wall 101a of the carrier 101 of the particulate filter 100. Each is formed. That is, the inflow / outflow hole 101c is formed by not sealing the inlet side and the outlet side of the plurality of through holes 101b with the sealing member 101e, and the inlet side of the plurality of through holes 101b is sealed with the sealing member 101e. And the outflow hole 101d is formed by opening the outlet side. A first catalyst layer 21 made of a silver-based catalyst is formed on the entire surface (the entire inner surface) of the inflow / outflow hole 101c so that the exhaust gas can pass therethrough, and the exhaust gas is formed on the entire surface (the entire inner surface) of the first catalyst layer 21. Is a second catalyst made of a copper-based catalyst, an iron-based catalyst, or a vanadium-based catalyst over the entire surface (the entire inner surface) of the outflow hole 101d. The layer 22 is formed in a state in which exhaust gas can pass. The configuration other than the above is the same as that of the first embodiment.

  In the exhaust gas purification apparatus configured as described above, the pressure on the outlet side of the particulate filter 100 is lower than that on the inlet side. More exhaust gas enters from the inlet of the inflow / outflow hole 101c, passes through the porous partition wall 101a, and exits from the outlet of the outflow hole 101d. As a result, as in the first embodiment, NOx and particulates in the exhaust gas can be efficiently reduced in the high temperature range of the exhaust gas. Further, although the man-hour for sealing the outlet portion of the outflow hole 101d with the sealing member 101e is necessary, the man-hour for sealing the inlet portion of the inflow / outflow hole 101c with the sealing member 101e is not necessary, and therefore the particulate filter 100. Manufacturing man-hours can be reduced. As a result, the manufacturing cost of the particulate filter 100 can be reduced. Since the operation other than the above is substantially the same as the operation of the first embodiment, repeated description is omitted.

<Third Embodiment>
FIG. 4 shows a third embodiment of the present invention. 4, the same reference numerals as those in FIG. 1 denote the same components. In this embodiment, the coating area and coating position on the inner surface of the inflow hole 24c of the first catalyst layer 121 and the coating area and coating position on the inner surface of the outflow hole 24d of the second catalyst layer 122 are determined by the particulate filter 120. It is configured to be set based on one or both of the pressure loss and the required reduction rate of NOx. Specifically, the first catalyst layer 121 is coated only on the half of the inlet side of the inflow hole 24 c of the filter 120, and the second catalyst layer 122 is coated only on the half of the outlet side of the outlet hole 24 d of the filter 120. The configuration other than the above is the same as that of the first embodiment.

  In the exhaust gas purification apparatus configured as described above, the amount of silver used for the first catalyst layer 121 and the amount of copper, iron, or vanadium used for the second catalyst layer 122 can be reduced. As a result, the manufacturing cost of the particulate filter 120 can be reduced. Further, although the NOx reduction rate is slightly reduced, the pressure loss of the filter 120 can be reduced. Since the operation other than the above is substantially the same as the operation of the first embodiment, repeated description is omitted.

<Fourth embodiment>
FIG. 5 shows a fourth embodiment of the present invention. 5, the same reference numerals as those in FIG. 3 denote the same components. In this embodiment, the particulate filter 140 has a coating area and a coating position on the inner surface of the inflow / outflow hole 101c of the first catalyst layer 121 and a coating area and a coating position on the inner surface of the outflow hole 101d of the second catalyst layer 122. It is configured to be set based on one or both of the pressure loss and the required reduction rate of NOx. Specifically, the first catalyst layer 121 is coated only on the half of the inlet side of the inflow / outflow hole 101c of the filter 140, and the second catalyst layer 122 is coated only on the half of the outlet side of the outflow hole 101d of the filter 140. . The configuration other than the above is the same as that of the second embodiment.

  In the exhaust gas purification apparatus configured as described above, the amount of silver used for the first catalyst layer 121 and the amount of copper, iron, or vanadium used for the second catalyst layer 122 can be reduced. As a result, the manufacturing cost of the particulate filter 140 can be reduced. Further, although the NOx reduction rate is slightly reduced, the pressure loss of the filter 140 can be reduced. Since the operation other than the above is substantially the same as the operation of the second embodiment, repeated description will be omitted.

  In the first to fourth embodiments, the exhaust gas purification apparatus of the present invention is applied to a diesel engine. However, the exhaust gas purification apparatus of the present invention may be applied to a gasoline engine. In the first to fourth embodiments, the exhaust gas purifying apparatus of the present invention is applied to a turbocharged diesel engine. However, the exhaust gas purifying apparatus of the present invention is applied to a naturally aspirated diesel engine or a naturally aspirated gasoline. It may be applied to the engine. Further, in the first and second embodiments, the first catalyst layer is coated on the entire surface of the inflow hole or the inflow / outflow hole (100%), and the second catalyst layer is coated on the entire surface of the outflow hole (100%). In the third and fourth embodiments, the first catalyst layer is coated only on the inlet side of the inlet hole or the inlet half of the inlet / outlet hole (50% of the entire surface), and the second catalyst layer is coated on the outlet of the outlet hole. Although only half of the side (50% of the entire surface) is coated, these are examples, and can be appropriately changed according to the pressure loss of the particulate filter and the required reduction rate of NOx.

  Next, examples of the present invention will be described in detail together with comparative examples.

<Example 1>
As shown in FIG. 2, the first oxidation-reduction catalyst 51, the particulate filter 20, and the second oxidation-reduction catalyst 72 were accommodated in order from the exhaust gas upstream side in the case 19 provided in the exhaust pipe 16. The first and second oxidation-reduction catalysts 51 and 72 were catalysts prepared by coating a honeycomb carrier with a slurry containing zeolite powder obtained by ion exchange of platinum.

  On the other hand, as shown in FIG. 1, the first catalyst layer 21 is formed on the entire surface (the entire inner surface) of the inflow hole 24 c of the filter 20 so that the exhaust gas can pass therethrough, and the entire surface (the entire inner surface) of the first catalyst layer 21. ) Is formed in a state in which the exhaust gas can pass through, and the second catalyst layer 22 is formed on the entire outflow hole 24d of the filter 20 (the entire inner surface). It was formed in a passable state. The first catalyst layer 21 was a silver-based catalyst layer produced by coating a filter carrier with a slurry containing zeolite powder ion-exchanged with silver. The second catalyst layer 22 was a copper-based catalyst layer prepared by coating a filter carrier with a slurry containing zeolite powder obtained by ion exchange of copper.

  Returning to FIG. 2, the first liquid injection nozzle 31 for injecting the hydrocarbon-based liquid 32 is provided in the case 19 on the exhaust gas upstream side of the filter 20 and on the exhaust gas downstream side of the first oxidation-reduction catalyst 51. A second liquid injection nozzle 72 is provided in the exhaust pipe 16 on the exhaust gas upstream side of the reduction catalyst 51. This exhaust gas purification apparatus was designated as Example 1.

<Comparative Example 1>
A first oxidation-reduction catalyst, a particulate filter, and a second oxidation-reduction catalyst were accommodated in the case provided in the exhaust pipe in order from the exhaust gas upstream side. The first and second oxidation-reduction catalysts were catalysts prepared by coating a honeycomb carrier with a slurry containing zeolite powder obtained by ion exchange of platinum. In addition, a catalyst layer was formed on the entire surface of the inflow hole and outflow hole of the filter (the entire inner surface) so that the exhaust gas can pass. The catalyst layer was a platinum-based catalyst layer prepared by coating a filter carrier with a slurry containing zeolite powder obtained by ion exchange of platinum. Furthermore, a second liquid injection nozzle was provided in the exhaust pipe upstream of the first redox catalyst. This exhaust gas purification apparatus was designated as Comparative Example 1.

<Comparative test 1 and evaluation>
The exhaust gas purification apparatuses of Example 1 and Comparative Example 1 were connected to the exhaust pipe of the gas generation apparatus. This gas generation device is configured to be able to generate and discharge model gas imitating exhaust gas. The model gas was a gas containing 200 ppm NO, 4000 ppm C light oil, 10 mass% O ₂ and 10 mass% H ₂ O. Further, the temperature of the model gas discharged from the gas generator is controlled by the electric furnace to room temperature, 150 ° C., 200 ° C., 300 ° C., 400 ° C., 500 ° C. and 600 ° C., and the space of the model gas at each temperature The speed (SV) was set to 50,000 h- ¹ . And the NOx reduction rate by the exhaust gas purification apparatus of Example 1 and the comparative example 1 when the temperature of the model gas discharged | emitted from a gas production | generation apparatus was raised in steps from room temperature to 600 degreeC was measured. The result is shown in FIG. Further, the amount of ammonia contained in the exhaust gas immediately after passing through the first catalyst layer of Example 1 was measured. The result is shown in FIG. The amount of ammonia was measured using a filter in which the second catalyst layer was not formed.

  As is clear from FIG. 6, the NOx reduction rate of the exhaust gas purification device of Comparative Example 1 was about 40% at the maximum, whereas the NOx reduction rate of Example 1 was about 50% at the maximum. It became high, and it turned out that the direction of the exhaust gas purification apparatus of Example 1 improved the NOx reduction rate over the exhaust gas temperature 200-600 degreeC rather than the exhaust gas purification apparatus of the comparative example 1. FIG. Further, as is apparent from FIG. 7, it was found that the amount of ammonia discharged from the first catalyst layer began to be generated when the model gas temperature was about 200 ° C., and gradually increased as the model gas temperature increased.

<Comparative test 2 and evaluation>
The exhaust gas purification apparatuses of Example 1 and Comparative Example 1 were connected to the exhaust pipe of a turbocharger-equipped diesel engine having a displacement of 8000 cc. And the total NOx reduction rate by the exhaust gas purification apparatus of Example 1 and Comparative Example 1 was measured when the exhaust gas temperature was gradually raised from room temperature to 600 ° C. by changing the engine speed and load. The result is shown in FIG.

  As is clear from FIG. 8, the total NOx reduction rate of the exhaust gas purification device of Comparative Example 1 was as low as about 30%, whereas the total NOx reduction rate of the exhaust gas purification device of Example 1 was about 40%. It became high and it turned out that the exhaust gas purification apparatus of Example 1 improved the total NOx reduction rate compared with the exhaust gas purification apparatus of Comparative Example 1.

11 Diesel engine (engine)
16 Exhaust pipes 20, 100, 120, 140 Particulate filters 21, 121 First catalyst layer 22, 122 Second catalyst layer 23, 123 Collection layer 24, 101 Carrier 24a, 101a Partition wall 24b, 101b Through hole 24c Inflow hole 24d , 101d Outflow hole 31 First liquid injection nozzle 32 Hydrocarbon liquid 41 First hydrocarbon liquid supply means 44 First liquid injection amount adjustment valve 51 First oxidation-reduction catalyst 52 Second liquid injection nozzle 62 Second hydrocarbon system Liquid supply means 64 Second liquid injection amount adjustment valve 72 Second oxidation-reduction catalyst 81 First temperature sensor 82 Second temperature sensor 86 Controller 101c Inflow / outflow hole

Claims (7)

The exhaust pipe (16) of the engine (11) is provided with a particulate filter (20, 120) for collecting particulates in the exhaust gas, and the particulate filter (20, 120) is partitioned by a porous partition wall (24a). The through hole (24b) has a carrier (24) formed in parallel with each other, and the outlet and inlet portions adjacent to each other of the plurality of through holes (24b) are alternately sealed so that the inflow holes (24c ) And the exhaust gas purification device in which the outflow hole (24d) is formed,
A first catalyst layer (21, 121) made of a silver-based catalyst is formed on all or part of the inner surface of the inflow hole (24c) so that the exhaust gas can pass therethrough,
A collection layer (23, 123) capable of collecting particulates in the exhaust gas is formed on the entire inner surface of the first catalyst layer (21, 121) in a state in which the exhaust gas can pass through,
A second catalyst layer (22, 122) made of a copper-based catalyst, an iron-based catalyst, or a vanadium-based catalyst is formed on all or part of the inner surface of the outflow hole (24d) in a state in which the exhaust gas can pass;
A first liquid injection nozzle (31) provided in an exhaust pipe (16) upstream of the particulate filter (20, 120) and capable of injecting a hydrocarbon-based liquid (32) toward the particulate filter (20, 120); ,
First hydrocarbon-based liquid supply means (41) for supplying the liquid (32) to the first liquid injection nozzle (31) via a first liquid injection amount adjustment valve (44);
A first temperature sensor (81) for detecting the temperature of exhaust gas related to the particulate filter (20, 120);
An exhaust gas purification apparatus comprising: a controller (86) for controlling the first liquid injection amount adjusting valve (44) based on a detection output of the first temperature sensor (81). A particulate filter (100, 140) for collecting particulates in the exhaust gas is provided in the exhaust pipe of the engine, and the particulate filter (100, 140) has a through hole (101b) partitioned by a porous partition wall (101a). In the exhaust gas purification apparatus having a plurality of carriers (101) formed in parallel with each other,
An inflow / outflow hole (101c) and an outflow hole (101d) are formed by sealing every other inlet portion of the plurality of through holes (101b),
A first catalyst layer (21, 121) made of a silver-based catalyst is formed on all or part of the inner surface of the inflow / outflow hole (101c) in a state in which the exhaust gas can pass;
A collection layer (23, 123) capable of collecting particulates in the exhaust gas is formed on the entire inner surface of the first catalyst layer (21, 121) in a state in which the exhaust gas can pass through,
A second catalyst layer (22,122) made of a copper-based catalyst, an iron-based catalyst or a vanadium-based catalyst is formed in a state in which the exhaust gas can pass over all or part of the inner surface of the outflow hole (101d);
A first liquid injection nozzle provided in an exhaust pipe upstream of the particulate filter (100, 140) and capable of injecting a hydrocarbon-based liquid toward the particulate filter (100, 140);
First hydrocarbon liquid supply means for supplying the liquid to the first liquid injection nozzle via a first liquid injection amount adjustment valve;
A first temperature sensor for detecting a temperature of exhaust gas related to the particulate filter (100, 140);
An exhaust gas purification apparatus comprising: a controller that controls the first liquid injection amount adjustment valve based on a detection output of the first temperature sensor.   The coating area and coating position on the inner surface of the inflow hole (24c) of the first catalyst layer (21, 121) and the coating area and coating position on the inner surface of the outflow hole (24d) of the second catalyst layer (22, 122). The exhaust gas purifying apparatus according to claim 1, wherein the exhaust gas purifying apparatus is configured to be set based on one or both of pressure loss of the particulate filter (20, 120) and a required reduction rate of the NOx.   The coating area and coating position of the first catalyst layer (21, 121) on the inner surface of the inflow / outflow hole (101c), and the coating area and coating position of the second catalyst layer (22, 122) on the inner surface of the outflow hole (101d) The exhaust gas purification device according to claim 2, wherein the exhaust gas purification device is configured to be set based on one or both of a pressure loss of the particulate filter (100, 140) and a required reduction rate of the NOx. A first oxidation-reduction catalyst (51) having an oxidation function and a NOx reduction function is provided in an exhaust pipe (16) upstream of the first liquid injection nozzle (31);
A second liquid injection nozzle (52) capable of injecting the hydrocarbon-based liquid (32) toward the first oxidation-reduction catalyst (51) into the exhaust pipe (16) upstream of the first oxidation-reduction catalyst (51). )
A second hydrocarbon-based liquid supply means (62) for supplying the liquid (32) to the second liquid injection nozzle (52) via a second liquid injection amount adjusting valve (64) is provided with the second liquid injection nozzle ( 52),
The temperature of the exhaust gas related to the first redox catalyst (51) is detected by a second temperature sensor (82),
The exhaust gas purification device according to claim 1 or 2, wherein the controller (86) is configured to control the second liquid injection amount adjusting valve (64) based on a detection output of the second temperature sensor (82).   The first catalyst layer (21, 121) is formed by coating a support (24, 101) of the particulate filter (20, 100, 120, 140) with silver zeolite or silver alumina, and the second catalyst layer (22, 122) is formed of the particulate filter (20, 100, 120, 140). The exhaust gas purifying apparatus according to claim 1 or 2, wherein said support (24,101) is formed by coating copper zeolite, iron zeolite or vanadium oxide.   A second oxidation-reduction catalyst (72) is provided in the exhaust pipe (16) downstream of the exhaust gas from the particulate filter (20, 100, 120, 140), and the second oxidation-reduction catalyst (72) is connected to the particulate filter (20, 100, 120, 140) from the particulate filter. An oxidation function for oxidizing the hydrocarbon liquid (32) when the hydrocarbon liquid (32) is discharged, and an oxidation function for oxidizing the ammonia when ammonia is discharged from the particulate filter (20, 100, 120, 140) 3. The exhaust gas purification apparatus according to claim 1, further comprising a reduction function of reducing the NOx when the NOx is exhausted from the particulate filter (20, 100, 120, 140).

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