JP5112986B2 - Exhaust purification device - Google Patents

Description

  The present invention relates to an exhaust emission control device.

  Particulate matter (particulate matter) discharged from a diesel engine is mainly composed of soot made of carbonaceous matter and SOF content (Soluble Organic Fraction) made of high-boiling hydrocarbon components. The composition contains a small amount of sulfate (mist-like sulfuric acid component). As a measure to reduce this type of particulates, a particulate filter is installed in the middle of the exhaust pipe through which the exhaust gas flows. It has been done conventionally.

  This type of particulate filter has a porous honeycomb structure made of ceramics such as cordierite, and the inlets of the flow paths partitioned in a lattice pattern are alternately sealed, and the inlets are not sealed. The outlet of the passage is sealed, and only the exhaust gas that has permeated through the porous thin wall defining each flow passage is discharged downstream, while the particulates in the exhaust gas are porous. It is collected on the inner surface of the thin wall.

  Then, the particulates in the exhaust gas are collected and deposited on the inner surface of the porous thin wall, so that the particulates are appropriately burned and removed before the exhaust resistance increases due to clogging. It is necessary to regenerate, but in normal diesel engine operating conditions, there are few opportunities to obtain exhaust temperatures that are high enough to cause the particulates to self-combust. The curate filter is integrally supported.

  That is, if such a particulate filter carrying an oxidation catalyst is employed, the oxidation reaction of the collected particulates is promoted to lower the ignition temperature, and the particulates are burned and removed even at a lower exhaust temperature than in the past. It becomes possible.

  However, even when such a particulate filter is adopted, the trapped amount exceeds the processing amount of particulates in the operation region where the exhaust temperature is low, so operation at such a low exhaust temperature is required. If the state continues, there is a possibility that the particulate filter will fall into an over trapped state without the regeneration of the particulate filter proceeding well.

  Therefore, a flow-through type oxidation catalyst is attached to the front stage of the particulate filter, and the particulate filter is forcibly regenerated by adding fuel upstream from the oxidation catalyst when the amount of particulate accumulation increases. Is considered.

  In other words, in this way, the hydrocarbon generated by the fuel addition undergoes an oxidation reaction while passing through the oxidation catalyst, and the flow of exhaust gas heated by the reaction heat increases the bed temperature of the particulate filter immediately after. Thus, the particulates are burned out, and the particulate filter is regenerated.

However, when an oxidation catalyst is attached to the front stage of the particulate filter in this way, if the SO ₂ gas originating from the sulfur content in the fuel (light oil) is present in the exhaust gas of the diesel engine, This SO ₂ gas has the following formula [Chemical Formula 1]
2SO ₂ + O ₂ + 2H ₂ O → 2H ₂ SO ₄
There was a concern that sulfate (mist-like sulfuric acid component) might be generated.

This type of sulfate is desorbed as SO ₂ gas again at a high temperature of about 630 ° C. or higher. However, when high sulfur fuel is used in developing countries, the amount of sulfate produced Because there is too much and caulking in which the surface of the inlet part of the oxidation catalyst is entirely covered with sulfate is caused in a short period of time, there is a risk that the function of the oxidation catalyst cannot be performed and the particulate filter cannot be regenerated. Therefore, a burner device is provided at the inlet of the oxidation catalyst, the temperature of the exhaust gas is significantly increased by the flame of the burner device, and the exhaust gas that has reached a high temperature is allowed to flow into the inlet of the oxidation catalyst. It has been studied to desorb sulfate as SO ₂ gas by heating the part.

Prior art document information relating to a technique for heating this type of catalyst or exhaust gas using a burner device includes the following Patent Document 1 and Patent Document 2.
JP-A-5-86845 JP-A-6-167212

  However, in order to heat all of the exhaust gas flowing into the oxidation catalyst to a high temperature of, for example, about 630 ° C. or higher, a burner device having a large capacity is required, so that there is a problem that the burner device is enlarged. As described above, when the high sulfur fuel is used, since the inlet portion of the oxidation catalyst is covered with sulfate in a short period of time, it is necessary to frequently operate the burner device to remove the sulfate of the oxidation catalyst. Therefore, there is a problem that a large amount of fuel is consumed and fuel consumption is greatly deteriorated.

  In addition, since a large amount of combustion air having a pressure that does not lose the exhaust pressure is required, it is necessary to take measures to branch and guide the intake air at the compressor outlet of the turbocharger. A flow path change accompanied by a large pipe remodeling that branches and guides intake air from the outlet of the compressor results in a significant increase in implementation cost.

  The present invention has been made in view of the above-described circumstances. The inlet of the oxidation catalyst is effectively heated by a small burner apparatus that minimizes the coking of sulfate to the oxidation catalyst, and has little fuel and combustion air. The purpose is to enable desulfurization of the part.

  The present invention relates to an exhaust emission control device for a diesel engine using a high sulfur fuel, an oxidation catalyst provided upstream of a particulate filter, and a regeneration flow path for guiding exhaust gas to the particulate filter via the oxidation catalyst. A normal flow path for directing the exhaust gas to the particulate filter by bypassing the oxidation catalyst, and a normal flow path is normally selected to flow the exhaust gas and at least during the desulfurization treatment of the oxidation catalyst A flow path switching means for switching from the flow path to the regeneration flow path, and further, an addition that is arranged on the axis x of the oxidation catalyst so as to face the center of the inlet portion of the oxidation catalyst and injects fuel together with combustion air A valve and a tip of the addition valve so as to be pivotable about the axis x of the oxidation catalyst and extending obliquely away from the axis x before the shaft Burner comprising: a swivel nozzle bent in a V shape so as to return to x and opening an injection port; and an ignition means disposed in the vicinity of the injection port of the swirl nozzle and igniting fuel injected from the injection port A device is provided.

  Thus, normally, the normal flow path is selected and the exhaust gas is allowed to flow to the particulate filter. Only when the particulate filter is regenerated, the exhaust gas is allowed to flow through the regeneration flow path and led to the particulate filter via the oxidation catalyst. Therefore, even in a diesel engine using a high sulfur fuel, the coking of sulfate with respect to the oxidation catalyst can be minimized.

  If sulfur-free fuel is supplied to the exhaust pipe upstream of the oxidation catalyst as regeneration fuel during regeneration of the particulate filter, the occurrence of sulfate coking can be further reduced.

  At the time of desulfurization treatment of the oxidation catalyst, the fuel is injected together with the combustion air by the addition valve while turning the swirling nozzle while the exhaust gas is switched to the regeneration flow path, and the injected fuel is ignited by the ignition means. The flame turns around the axis of the oxidation catalyst with the ignition point as the center of immobilization, and it is possible to directly heat the oxidation catalyst inlet part while changing the position in turn in the turning direction of the turning nozzle. It becomes.

As a result, the entire area in the circumferential direction of the inlet portion of the oxidation catalyst is heated to about 630 ° C. or more by the flame swirling around the axis of the oxidation catalyst, and the sulfate stored therein is desorbed as SO ₂ gas, and the inlet portion of the oxidation catalyst The desulfurization process will be performed.

  If sulfur-free fuel is supplied to the burner device as desulfurization fuel during the desulfurization treatment of the oxidation catalyst, it is possible to prevent the generation of sulfate during desulfurization.

  Further, in the present invention, the flame divided into the swirling direction of the swirl nozzle and received from the revolving nozzle so that the flame can be individually received between the swirl nozzle and the inlet of the oxidation catalyst. It is preferable to dispose a flame guide having a plurality of guide channels so that the oxidation catalyst can be guided to the immediate vicinity of the inlet and then blown out radially outward of the inlet.

  In this way, the flame from the swirling nozzle is individually received in the guide flow path of the flame guide and is appropriately oriented, and the flame guide is heated to contribute to maintaining the ignition of the injected fuel. Furthermore, the swirl nozzle and the ignition means are not directly exposed to the exhaust gas on the oxidation catalyst side, so that the adhesion of soot to the ignition means and the swirl nozzle is greatly suppressed.

  According to the exhaust emission control device of the present invention described above, various excellent effects as described below can be obtained.

  (I) According to the invention described in claim 1 of the present invention, the normal flow path is normally selected and the exhaust gas is allowed to flow through the particulate filter, and the exhaust gas is allowed to flow through the regeneration flow path only during regeneration of the particulate filter. Since the catalyst is guided to the particulate filter via the oxidation catalyst, sulfate coking with respect to the oxidation catalyst can be minimized even in a diesel engine using a high sulfur fuel. Further, when sulfur-free fuel is supplied as regeneration fuel to the exhaust pipe upstream of the oxidation catalyst during regeneration of the particulate filter, the occurrence of sulfate coking can be further reduced.

At the time of desulfurization treatment of the oxidation catalyst, the fuel is injected together with the combustion air by the addition valve while turning the swirling nozzle while the exhaust gas is switched to the regeneration flow path, and the injected fuel is ignited by the ignition means. The inlet of the oxidation catalyst is locally heated by the flame of the swirling nozzle while changing its position in the swirl direction in turn, and as a result, the sulfate accumulated at the inlet of the oxidation catalyst is desorbed as SO ₂ gas. Thus, desulfurization treatment is performed at the inlet of the oxidation catalyst. As described above, since the inlet of the oxidation catalyst can be locally heated to about 630 ° C. or more by the flame of the swirl nozzle, the generation of coking is reduced and the fuel is also used for the combustion air. With a small number of small burner devices, it is possible to effectively achieve desulfurization at the inlet of the oxidation catalyst, which can significantly improve fuel efficiency and branch the intake air from the outlet of the turbocharger compressor. Even if there is no need to change the flow path with large-scale piping modification, the small amount of air can be easily guided from an air tank or the like, and the implementation cost can be reduced. Further, when sulfur-free fuel is supplied to the burner device as desulfurization fuel during the desulfurization treatment of the oxidation catalyst, it is possible to prevent the generation of sulfate during desulfurization.

  (II) According to the invention described in claim 2 of the present invention, the inlet of the oxidation catalyst can be efficiently heated by appropriately directing the flame from the swivel nozzle by the guide channel of the flame guide. In addition, the flame guide can be heated to make the injected fuel easier to ignite, and the flame can be stabilized. In addition, the adhesion of soot to the ignition means and swirl nozzle is greatly suppressed, resulting in malfunction. Can be avoided in advance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 4 show an example of an embodiment for carrying out the present invention. Reference numeral 1 in FIG. 1 denotes a diesel engine equipped with a turbocharger 2, and intake air 4 guided from an air cleaner 3 is an intake pipe. 5, the intake air 4 sent to the compressor 2 a of the turbocharger 2 and pressurized by the compressor 2 a is sent to the intercooler 6 to be cooled, and the intake air 4 further flows from the intercooler 6 to the intake manifold 7. Is distributed to each cylinder 8 of the diesel engine 1 (the case of in-line 6 cylinders is illustrated in FIG. 1).

  The exhaust gas 9 discharged from each cylinder 8 of the diesel engine 1 is sent to the turbine 2b of the turbocharger 2 via the exhaust manifold 10, and is sent to the exhaust pipe 11 after driving the turbine 2b. However, the filter case 12 is interposed at the end of the exhaust pipe 11, and the particulate filter 13 is accommodated on the rear stage side in the filter case 12. The particulate filter 13 may be a catalyst regeneration type in which an oxidation catalyst is supported integrally, or may not be supported on an oxidation catalyst.

  This particulate filter 13 has a porous honeycomb structure made of ceramic, and the inlets of the respective flow paths partitioned in a lattice pattern are alternately sealed. The outlet is sealed, and only the exhaust gas 9 that has permeated through the porous thin wall partitioning each flow path is discharged downstream.

  Further, a flow-through type oxidation catalyst 14 is provided upstream of the particulate filter 13 in the filter case 12, and the sulfur-free fuel 16 stored in the fuel tank 15 is supplied to the pump 17, the pipe 18, and the fuel. Hydrocarbon produced from the added fuel is added to the exhaust pipe 11 through a regenerated fuel supply means 20 comprising a supply valve 19 and oxidized by the oxidation catalyst 14, and the exhaust gas 9 is raised by the reaction heat. The temperature of the particulate filter 13 immediately after heating is raised, and the particulate filter 13 is burned out to regenerate the particulate filter 13. Here, the particulate filter 13 is arranged so that the gas flow direction is in the direction of the axis of the filter case 12, whereas the oxidation catalyst 14 has the gas flow direction in the axis of the filter case 12. It is arrange | positioned in the direction orthogonal to it.

  An exhaust pipe 11 connecting the position where the sulfur-free fuel 16 is added by the nozzle 21 and the filter case 12 is connected to a regeneration flow path 22 for guiding the exhaust gas 9 to the oxidation catalyst 14 via the oxidation catalyst 14. The exhaust gas 9 is bifurcated into a normal flow path 23 that bypasses the oxidation catalyst 14 and leads directly to the particulate filter 13, and the normal flow path 23 is normally selected and exhausted at that branch point. A butterfly valve 24 for switching the flow of the exhaust gas 9 from the normal flow path 23 to the regeneration flow path 22 when it is necessary to flow the gas 9 and perform the regeneration process of the particulate filter 13 and the desorption process of the oxidation catalyst 14 occurs. It is provided as switching means.

  As shown in FIGS. 1 and 2, an annular inlet chamber 25 is fitted over the oxidation catalyst 14 at the front end of the filter case 12, and the inlet chamber 25 is appropriately positioned in the circumferential direction. The regeneration passage 22 branched from the exhaust pipe 11 that guides the exhaust gas 9 from the diesel engine 1 is connected to the inside of the inlet chamber 25, and the exhaust gas 9 from the regeneration passage 22 is passed in the circumferential direction. A dispersion plate 26 having a communication hole 26a for guiding the catalyst uniformly to the oxidation catalyst 14 is provided.

  A burner device 27 is provided at the center upper position of the inlet chamber 25 so that the inlet portion of the oxidation catalyst 14 can be heated to desulfurize the inlet portion. As shown in FIG. 3 in an enlarged manner, the burner device 27 includes an addition valve 28 disposed on the axis x of the oxidation catalyst 14 so as to face the center of the inlet portion of the oxidation catalyst 14, and a tip of the addition valve 28. And a discharge nozzle 31 (ignition means) disposed in the vicinity of the injection port 30 of the swirl nozzle 29. Yes.

  Here, combustion air is supplied to the base end portion of the addition valve 28 by an air hose 34 guided from an air tank 32 (see FIG. 1) through an on-off valve 33, and the fuel tank 15 (see FIG. 1). The sulfur-free fuel 16) is supplied via a desulfurized fuel supply means 36 comprising a pump 17, a pipe 35, and fuel so that it can be injected together with combustion air. In FIG. 1, the regenerated fuel supply means 20 and the desulfurized fuel supply means 36 share the same fuel tank 15 to supply the sulfur-free fuel 16, but each has a single fuel tank 15 and is provided with a sulfur fuel. Free fuel 16 may be supplied. If there is no sulfur-free fuel, diesel engine fuel may be used, and a dedicated fuel tank can be dispensed with.

  The swivel nozzle 29 has a base end portion rotatably mounted on the tip end portion of the addition valve 28 via a bearing or the like, and driving gear teeth 37 are engraved on the outer periphery of the base end portion. A pinion 38 meshing with the drive gear teeth 37 is rotated by an electric motor 39 so that the pinion 38 can turn about the axis x of the oxidation catalyst 14.

  In addition, the swivel nozzle 29 extends obliquely away from the axis x of the oxidation catalyst 14 and then bends in a V shape so as to return to the axis x so as to open the injection port 30. The fuel injected from the injection port 30 is ignited by discharge from the discharge terminal 31 (ignition means).

  3 and 4, a flame guide 40 is provided between the swivel nozzle 29 and the inlet of the oxidation catalyst 14, and the flame guide 40 is an injection port 30 of the swirl swivel nozzle 29. The flame is divided into the swirl direction of the swivel nozzle 29 so as to individually accept the flames from the flame, and the received flame is guided to the immediate vicinity of the inlet portion of the oxidation catalyst 14 and then blown out radially outward of the inlet portion. The guide flow path 41 is provided, and the whole is made of stainless steel having high heat resistance. Reference numerals 42 and 43 denote gaskets.

  The operation of the diesel engine 1, the switching operation of the butterfly valve 24 (flow path switching means), the operation of the pump 17, the operation of the fuel supply valve 19, the operation of the addition valve 28, and the operation of the electric motor 39 are not shown by engine control. It is controlled by a control device comprising a computer (ECU: Electronic Control Unit). In FIG. 1, reference numeral 44 is an EGR pipe for recirculating the exhaust gas 9 from the exhaust side to the intake side, 45 is a water-cooled EGR cooler for cooling a part of the recirculated exhaust gas 9, 46 Denotes an EGR valve, and 47 denotes an exhaust extraction pipe provided at the rear end of the filter case 12.

  1 to 4, the butterfly valve 24 (flow path switching means) is switched so that the normal flow path 23 is normally selected, and the particulate filter 13 is indicated by the solid line of the exhaust gas 9. It is made to flow to.

  At the time of regeneration of the particulate filter 13, the butterfly valve 24 (flow path switching means) is switched to cause the exhaust gas 9 to flow through the regeneration flow path 22 as indicated by a one-dot chain line, and then led to the particulate filter 13 via the oxidation catalyst 14. Then, the sulfur-free fuel 16 from the fuel tank 15 is supplied to the exhaust pipe 11 through the nozzle 21 by the regenerated fuel supply means 20 and the temperature of the exhaust gas 9 is raised through the oxidation catalyst 14, thereby the floor of the particulate filter 13. The temperature is raised, the particulates collected here are burned out, and the particulate filter 13 is regenerated.

  The regeneration of the particulate filter 13 is performed at predetermined time intervals or based on an increase in the pressure difference before and after the particulate filter 13. As described above, only when the particulate filter 13 is regenerated, the regeneration channel 22 is regenerated. Since exhaust gas 9 is allowed to flow, the coking of sulfate with respect to the oxidation catalyst 14 can be minimized even in a diesel engine using a high sulfur fuel. In addition, when the particulate filter 13 is regenerated, the sulfur-free fuel 16 is supplied as the regenerated fuel to the exhaust pipe 11 upstream from the oxidation catalyst 14, so that the occurrence of sulfate coking can be further reduced.

  As a result, the occurrence of sulfate coking with respect to the oxidation catalyst 14 is reduced. However, when long-term operation is performed, the sulfate coking gradually increases. 14 needs to be desulfurized.

  During the desulfurization treatment of the oxidation catalyst 14, the fuel by the regenerated fuel supply means 20 is made while the swivel nozzle 29 is swung while the butterfly valve 24 (flow path switching means) is switched so that the exhaust gas 9 flows through the regenerative flow path 22. When the sulfur-free fuel 16 from the tank 15 is supplied to the addition valve 28, the combustion air from the air tank 32 is supplied to the addition valve 28 and injected together, and the injected fuel is ignited at the discharge terminal 31 (ignition means). The flame turns around the axis x of the oxidation catalyst 14 with the ignition point as a stationary center, and the inlet portion of the oxidation catalyst 14 is heated directly and locally while changing the position in the turning direction of the turning nozzle 29. As a result, it is possible to evaporate the sulfate generated at the inlet of the oxidation catalyst 14.

Here, the SO ₂ component in the exhaust gas 9 by the sulfur fuel is sulfated by the reaction with the oxidation catalyst 14, but this reaction is very fast, and the sulfate accumulates in the range of several mm at the inlet of the oxidation catalyst 14. Further, when the amount of sulfate increases, the oxidation catalyst 14 accumulates inside. However, as described above, at the stage where the amount of sulfate accumulation is small, the swivel nozzle 29 swirls the inlet portion of the oxidation catalyst 14. Desulfurization can be achieved by local heating in the direction.

  Accordingly, by locally heating the inlet portion of the oxidation catalyst 14 to about 630 ° C. or more by the flame of the swirl nozzle 29, the fuel and the combustion air are combined with the reduction in the occurrence of coking as described above. The small-sized burner device 27 can effectively achieve the desulfurization treatment at the inlet of the oxidation catalyst 14 and can significantly improve the fuel efficiency. Also, the combustion air is sucked from the outlet of the turbocharger compressor. Even if there is no need to change the flow path with a large-scale piping modification such as branching and guiding, a small amount of air can be easily guided from the air tank 32 or the like, and the implementation cost can be reduced. Further, when the sulfur-free fuel 16 is supplied to the burner device 27 as the desulfurization fuel during the desulfurization treatment of the oxidation catalyst 14, it is possible to prevent the generation of sulfate during the desulfurization.

  In addition, since the flame guide 40 is disposed between the swivel nozzle 29 and the inlet of the oxidation catalyst 14, the flame from the swivel nozzle 29 is appropriately directed by the guide flow path 41 of the flame guide 40, and the oxidation catalyst. 14 can be efficiently heated, and the flame guide 40 can be heated to facilitate the ignition of the injected fuel, thereby stabilizing the flame. (Ignition means) and soot adhesion to the swivel nozzle 29 can be greatly suppressed to prevent the occurrence of malfunction.

  FIG. 5 shows the case where the particulate filter 13 and the oxidation catalyst 14 are arranged concentrically inside the filter case 12, and the burner device 27 is arranged concentrically with the oxidation catalyst 14. Other configurations are the same as those of the embodiment shown in FIGS. 1 and 3, and the same operational effects as described above can be obtained.

  FIGS. 6 and 7 show the case of a box filter in which the particulate filter 13 and the oxidation catalyst 14 are concentrically arranged in a box-shaped filter case 48. The particulate filter 13 and the oxidation catalyst 14 are shown in FIGS. A box-shaped filter case 48 is fixed to the frame 49 so that its axis is vertical, and a burner device 27 is disposed concentrically with the oxidation catalyst 14 and is led out from the lower part of the particulate filter 13. Except for having an exhaust extraction pipe 47 that guides the exhaust gas 9 from the upper part to the outside through the inside of the box-shaped filter case 48, the same effect as described above can be achieved.

Note that the exhaust purification apparatus of the present invention is not limited to the above-described embodiment. The oxidation catalyst targeted by the present invention oxidizes SO ₂ gas when a high sulfur fuel is used, and sulfates. All catalysts with oxidation promotion performance that generate NO are included, and any catalyst with this type of oxidation promotion performance can be applied in the same manner even if it is called a NOx storage reduction catalyst. Of course, the flame guide may be additionally provided as necessary, and various modifications may be made without departing from the scope of the present invention.

1 is an overall schematic diagram illustrating an example of an embodiment for carrying out the present invention. It is the perspective view which fractured | ruptured a part which shows the detail of the inlet chamber of FIG. It is sectional drawing which shows the detail of the burner apparatus of FIG. It is a perspective view which shows the detail of the flame guide of FIG. It is a schematic sectional drawing which shows the other example of the form which implements this invention. It is a front view which shows the further another example of the form which implements this invention. It is the cutting | disconnection top view which looked at FIG. 6 from the VII-VII direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Diesel engine 11 Exhaust pipe 13 Particulate filter 14 Oxidation catalyst 16 Sulfur free fuel 20 Regenerated fuel supply means 22 Regenerated flow path 23 Normal flow path 24 Butterfly valve (flow path switching means)
27 Burner device 28 Addition valve 29 Swiveling nozzle 30 Injection port 31 Discharge terminal (ignition means)
36 Desulfurized fuel supply means 40 Flame guide 41 Guide flow path x Oxidation catalyst axis

Claims (4)

  An exhaust emission control device for a diesel engine using high sulfur fuel, an oxidation catalyst provided upstream of a particulate filter, a regeneration passage for guiding exhaust gas to the particulate filter via the oxidation catalyst, and an exhaust gas The normal flow path that bypasses the oxidation catalyst and leads directly to the particulate filter, and the normal flow path is normally selected to flow exhaust gas, and at least during the desulfurization treatment of the oxidation catalyst, the exhaust gas flow is regenerated from the normal flow path A flow path switching means for switching to the flow path, and further, an addition valve disposed on the axis x of the oxidation catalyst so as to face the center of the inlet portion of the oxidation catalyst and injecting fuel together with combustion air, The tip of the addition valve is equipped so as to be able to swivel about the axis x of the oxidation catalyst and extends obliquely away from the axis x and then returns to the axis x In this way, a burner device comprising a swivel nozzle bent in a V shape and opening an injection port, and an ignition means disposed near the injection port of the swirl nozzle and igniting fuel injected from the injection port is provided. An exhaust purification device characterized by that.   Between the swirl nozzle and the inlet of the oxidation catalyst, the swirl nozzle is divided in the swirl direction so that the flame can be individually received from the injection nozzle of the swirl nozzle, and the received flame is disposed in the immediate vicinity of the inlet of the oxidation catalyst. The exhaust emission control device according to claim 1, further comprising a flame guide provided with a plurality of guide passages so that the gas guide can be blown out radially outward of the inlet portion. The exhaust emission control device according to claim 1 or 2, further comprising desulfurization fuel supply means for supplying fuel or sulfur-free fuel to the burner device to prevent generation of sulfate with respect to the oxidation catalyst .   The exhaust gas according to any one of claims 1 to 3, further comprising regenerated fuel supply means for regenerating the particulate filter by supplying fuel or sulfur-free fuel to an exhaust pipe upstream of the oxidation catalyst. Purification equipment.

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