JP7604227B2 - Denitrification catalyst polishing equipment - Google Patents

Description

The present invention relates to a de-nitrification catalyst polishing device for polishing de-nitrification catalysts.

At thermal power plants, nitrogen oxides are generated when coal is burned. To protect the environment, nitrogen oxide emissions must be kept below a certain level. For this reason, thermal power plants are equipped with de-nitrification equipment filled with de-nitrification catalysts to reduce nitrogen oxides. The performance of de-nitrification catalysts deteriorates with continued use. One technique for regenerating de-nitrification catalysts with reduced performance is polishing regeneration. Polishing regeneration is a technique that restores catalytic performance by polishing the surface of de-nitrification catalysts with reduced performance.

International Publication No. 2014/155628

Patent Document 1 discloses a technique for regenerating a denitration catalyst in which a mixture of an abrasive (grinding material) and gas is passed through the through-holes of the denitration catalyst to grind the inner walls of the through-holes. An upstream fixed member having an expansion section with a cross-sectional area larger than the cross-sectional area of the member to be ground, which is made of a denitration catalyst, is connected to one end of the member to be ground. A screen member is disposed in the expansion section. Within this expansion section, the flow rate of the mixture of abrasive and gas is reduced and dispersed, enabling uniform grinding of the inner walls of the through-holes.

The technology disclosed in Patent Document 1 requires the flow path length of the upstream fixed member to be at least a certain length in order to reduce the flow rate of the mixture of abrasive and gas and to disperse it sufficiently. However, if the flow path length of the upstream fixed member is increased, there is an issue that the polishing device cannot be configured compactly.

The present invention has been made in consideration of the above, and aims to provide a de-nitration catalyst polishing device that can uniformly disperse the abrasive flowing into the de-nitration catalyst and uniformly polish the de-nitration catalyst.

The present invention relates to a denitration catalyst polishing device that polishes the inner surface of a denitration catalyst having a plurality of through holes extending in the longitudinal direction by circulating an abrasive together with air through the through holes. The device has a mixing section that is arranged upstream of the denitration catalyst and mixes the abrasive with air, an inflow passage that is arranged between the mixing section and the denitration catalyst and through which the abrasive mixed with air flows, and a suction section that is arranged downstream of the denitration catalyst and sucks the abrasive and the object to be polished together with air. The inflow passage has a buffer member that reduces the flow rate of the abrasive mixed with air, a first regulating member that is arranged upstream of the buffer member and in the center of the cross section of the inflow passage, and a second regulating member that is arranged upstream of the first regulating member and at both ends of the cross section of the inflow passage.

The inlet passage has an upstream fixed member that fixes the denitration catalyst, and an upstream flow path that is arranged upstream of the upstream fixed member and has a bent portion, and it is preferable that the flow path direction of the upstream fixed member is the same as the flow path direction of the through hole, and that the buffer member, the first regulating member, and the second regulating member are arranged within the flow path of the upstream fixed member.

The first regulating member and the second regulating member may have a substantially rectangular parallelepiped shape and be arranged so that their longitudinal direction is perpendicular to the inflow direction of the upstream flow path.

The second regulating member may comprise an outer regulating portion arranged on the outer side of the bent portion and an inner regulating portion arranged on the inner side of the bent portion, and the area of the outer regulating portion in the cross section of the flow path may be larger than the area of the inner regulating portion in the cross section of the flow path.

The first regulating member and the second regulating member may have a substantially rectangular parallelepiped shape and be arranged so that their longitudinal direction is parallel to the inflow direction of the upstream flow path.

It is preferable that the buffer member is made of two or more mesh members, and that the openings of at least one set of the mesh members are arranged at positions offset from each other in the flow path direction.

The present invention provides a de-nitration catalyst polishing device that can uniformly disperse the abrasive flowing into the de-nitration catalyst and uniformly polish the de-nitration catalyst.

1 is a configuration diagram of a thermal power plant in which a denitration catalyst according to an embodiment of the present invention is used. FIG. 1 is a diagram showing an example of the configuration of a denitrification device in a thermal power generation facility. 1 is a schematic configuration diagram of a denitration catalyst polishing apparatus according to a first embodiment. 1 is a cross-sectional view of a main part of a polishing apparatus for a denitration catalyst according to a first embodiment. 1 is an exploded perspective view of a main part of a polishing apparatus for a denitration catalyst according to a first embodiment; FIG. 6 is an exploded perspective view of a main part of a polishing apparatus for a denitration catalyst according to a second embodiment. FIG. 4 is an enlarged view of a main part of a denitration catalyst polishing apparatus according to another embodiment.

Hereinafter, an embodiment of the present invention will be described.
The denitration catalyst to be polished by the denitration catalyst polishing apparatus according to the embodiment of the present invention is, for example, a denitration catalyst C that has been used for a certain period of time in a coal-fired power plant 100 described below and has deteriorated in performance.

[Coal-fired power generation facilities]
As shown in FIG. 1, the coal-fired power generation facility 100 includes a coal bunker 110, a coal feeder 115, a coal pulverizer 120, a pulverized coal supply pipe 130, a combustion boiler 140, an exhaust passage 150 provided downstream of the combustion boiler 140, a denitration device 160 provided in the exhaust passage 150, an air preheater 170, a heat recovery gas heater 180, an electrostatic precipitator 190, an induced draft fan 210, a wet desulfurization device 220, a reheat gas heater 230, a desulfurization fan 240, and a chimney 250.

The coal bunker 110 stores coal supplied from a coal silo (not shown) by a coal transport facility. The coal feeder 115 supplies the coal supplied from the coal bunker 110 to the coal pulverizer 120 at a predetermined supply speed.
The coal pulverizer 120 pulverizes the coal supplied from the coal feeder 115 to an average particle size of 60 μm to 80 μm to produce pulverized coal. As the coal pulverizer 120, a roller mill, a tube mill, a bora mill, a beater mill, an impeller mill, or the like is used.

The combustion boiler 140 burns the pulverized coal supplied from the pulverized coal supply pipe coal pulverizer 130 with forcibly supplied air by the pulverized coal burner b. By burning the pulverized coal, coal ash such as clinker ash and fly ash is generated, and exhaust gas is generated. The clinker ash refers to the coal ash in the form of lumps that fall to the bottom of the combustion boiler 140. The fly ash refers to the coal ash with a small particle size (particle size of about 200 μm or less) that flows into the exhaust passage 150 side together with the exhaust gas.
The exhaust passage 150 is disposed downstream of the combustion boiler 140 and allows the exhaust gas and coal ash generated in the combustion boiler 140 to flow therethrough.

The denitration device 160 removes nitrogen oxides from the exhaust gas. The denitration device 160 removes nitrogen oxides from the exhaust gas, for example, by dry ammonia catalytic reduction. The dry ammonia catalytic reduction method involves injecting ammonia gas as a reducing agent into exhaust gas at a relatively high temperature (300°C to 400°C), and decomposing the nitrogen oxides in the exhaust gas into nitrogen and water vapor through the action of a denitration catalyst.

2, the denitration device 160 includes a denitration reactor 161 in which a denitration reaction takes place, and a plurality of denitration catalyst layers 162 disposed inside the denitration reactor 161. The denitration catalyst layers 162 are composed of a plurality of casings 163. A plurality of denitration catalysts C are housed in the casings 163.
The denitration catalyst C is an elongated (rectangular) catalyst having a honeycomb structure with a plurality of through holes C1 extending in the longitudinal direction. The plurality of denitration catalysts C are arranged such that the extension direction of the through holes C1 is along the flow path of the exhaust gas.

The air preheater 170 is disposed downstream of the denitration device 160 in the exhaust passage 150. The air preheater 170 exchanges heat between the exhaust gas that has passed through the denitration device 160 and the combustion air, cooling the exhaust gas and heating the combustion air. The heated combustion air is supplied to the boiler 140 by the forced draft fan 175.

The heat recovery gas heater 180 is disposed downstream of the air preheater 170 in the exhaust passage 150. The heat recovery gas heater 180 is supplied with exhaust gas whose heat has been recovered in the air preheater 170. The heat recovery gas heater 180 further recovers heat from the exhaust gas.

The electrostatic precipitator 190 is disposed downstream of the heat recovery gas heater 180 in the exhaust passage 150. The electrostatic precipitator 190 is supplied with exhaust gas whose heat has been recovered in the heat recovery gas heater 180. The electrostatic precipitator 190 is a device that collects (captures) coal ash (fly ash) in the exhaust gas by applying a voltage to the electrodes. The fly ash collected (captured) in the electrostatic precipitator 190 is collected in the fly ash recovery device 191.

The induced draft fan 210 is disposed downstream of the electrostatic precipitator 190 in the exhaust passage 150. The induced draft fan 210 takes in the exhaust gas from which the fly ash has been removed by the electrostatic precipitator 190 from the primary side and sends it out to the secondary side.

The desulfurization device 220 is disposed downstream of the induced draft fan 210 in the exhaust passage 150. The desulfurization device 220 is supplied with the exhaust gas sent out from the induced draft fan 210. The desulfurization device 220 removes sulfur oxides from the exhaust gas, for example, by a wet lime-gypsum method. The wet lime-gypsum method is a method in which a mixture of limestone and water is sprayed onto the exhaust gas, causing the sulfur oxides contained in the exhaust gas to be absorbed by the mixture to generate a desulfurized gypsum slurry, thereby removing the sulfur oxides from the exhaust gas. The wastewater generated during this process, which contains trace substances such as boron and selenium, is treated by the wastewater treatment device 221.

The reheating gas heater 230 is disposed downstream of the desulfurization device 220 in the exhaust passage 150. The reheating gas heater 230 is supplied with exhaust gas from which sulfur oxides have been removed in the desulfurization device 220. The reheating gas heater 230 heats the exhaust gas. The heat recovery gas heater 180 and the reheating gas heater 230 may be configured as a gas-gas heater that performs heat exchange between the exhaust gas flowing between the air preheater 170 and the electrostatic precipitator 190 in the exhaust passage 150 and the exhaust gas flowing between the desulfurization device 220 and the desulfurization fan 240.

The desulfurization fan 240 is disposed downstream of the reheat gas heater 230 in the exhaust passage 150. The desulfurization fan 240 takes in the exhaust gas heated in the reheat gas heater 230 from the primary side and sends it out to the secondary side.

The chimney 250 is disposed downstream of the desulfurization fan 240 in the exhaust passage 150. Exhaust gas heated by the reheat gas heater 230 is introduced into the chimney 250. The chimney 250 discharges the exhaust gas.

[Denitrification catalyst polishing equipment]
The denitration catalyst C used in the above-described coal-fired power plant 100 is subject to thermal deterioration such as sintering, chemical deterioration due to poisoning of the catalyst components, and physical deterioration due to soot coating the catalyst surface as a result of continued use. The denitration performance of the denitration catalyst C with the denitration performance deteriorates due to the above reasons. The denitration performance of the denitration catalyst C with the denitration performance deteriorated can be restored by polishing the inner surface of the through hole C1, which is the catalyst surface, and removing the deposits on the surface.
Hereinafter, a description will be given of a denitration catalyst polishing device 1 that polishes the inner surface of the through hole C1 of a denitration catalyst C whose denitration performance has deteriorated, thereby recovering the denitration performance.

First Embodiment
The denitration catalyst polishing apparatus 1 according to this embodiment is an apparatus for polishing the inner surface of the through hole C1 of the denitration catalyst C by circulating an abrasive A together with air through the through hole C1. As shown in Fig. 3, the denitration catalyst polishing apparatus 1 includes a mixer 10, an inlet passage 20, an outlet passage 30, a cyclone 40, a compressor 50, a bag filter 60, and a suction fan 70. The denitration catalyst C, which is the object to be polished by the denitration catalyst polishing apparatus 1, is sandwiched between an upstream fixing member 22 in the inlet passage 20 and a downstream fixing member 32 in the outlet passage 30. The denitration catalyst C is fixed so that the flow direction of the through hole C1 of the denitration catalyst C is approximately perpendicular to a horizontal plane.

The mixing section 10 mixes air and abrasive A, and supplies the abrasive A mixed with air to the denitrification catalyst C through the inflow passage 20. The mixing section 10 is provided with a blast gun 11, a funnel section 12, and a cabinet 13 that houses them. The blast gun 11 is connected to a compressor 50 through an air hose 51 and can inject compressed air. A plurality of blast guns 11 may be provided. The blast gun 11 is connected to an abrasive supply passage 33, which will be described later. When compressed air is injected from the blast gun 11, an ejector effect occurs, and the abrasive A is supplied into the blast gun 11 through the abrasive supply passage 33. Then, the abrasive A and the compressed air are mixed inside the blast gun 11 and injected into the funnel section 12. The injected abrasive A flows into the inflow passage 20 through the funnel section 12 in a state where it is uniformly mixed with air.

The inlet passage 20 is a flow path upstream of the denitration catalyst C, and is a flow path through which the abrasive A mixed with air flows. The inlet passage 20 consists of an upstream flow path 21 and an upstream fixing member 22. The upstream flow path 21 is a flow path with a bent portion, and the upstream side is connected to the funnel portion 12, and the downstream side is connected to the upstream fixing member 22. The upstream fixing member 22 has a straight flow path, and the downstream side is connected to the lower end (upstream end) of the denitration catalyst C to fix the denitration catalyst C. The configurations of the upstream flow path 21 and the upstream fixing member 22 will be described in detail later.

The outflow path 30 is a flow path downstream of the denitration catalyst C. The outflow path 30 is a flow path through which the abrasive A and the object to be polished generated by polishing the surface of the denitration catalyst C flow. The abrasive A and the object to be polished are sucked together with air by a suction fan 70 serving as a suction section. A cyclone 40 is provided midway through the outflow path 30, and the abrasive A and the object to be polished are separated.
The outflow path 30 has a downstream fixing member 32 that is connected to the upper end (downstream end) of the denitration catalyst C to fix the denitration catalyst C, a downstream flow path 31 that connects the downstream fixing member 32 to the cyclone 40, and an abrasive supply path 33 that connects the cyclone 40 to the mixing section 10.

The cyclone 40 is a known cyclone classifier and is positioned higher than the mixing section 10. The upstream end of the cyclone 40 is connected to the downstream flow path 31. The abrasive supply path 33 is connected to the bottom of the cyclone 40, and the abrasive A separated by the cyclone 40 falls by gravity through the abrasive supply path 33 and is supplied to the mixing section 10. The downstream end of the cyclone 40 is connected to the conveying pipe 41, and the downstream end of the conveying pipe 41 is connected to the bag filter 60. The polished material separated by the cyclone 40 flows into the bag filter 60 through the conveying pipe 41 together with air.

The bag filter 60 is a known dust collecting device. The bag filter 60 captures dust particles in the air, including the object to be polished of the denitrification catalyst C. The captured dust particles are stored in a storage unit (not shown) provided at the bottom of the bag filter 60, and are collected at the desired timing. The downstream end of the bag filter 60 is connected to a connecting pipe 61. The downstream end of the connecting pipe 61 is connected to a suction fan 70 as a suction unit. The clean air from which dust particles have been removed by passing through the bag filter 60 is sucked in by the suction fan 70 and discharged into the atmosphere by an exhaust duct 71.

Next, the details of the configuration of the upstream flow path 21 and the upstream fixing member 22 of the denitration catalyst polishing apparatus 1 according to this embodiment will be described below with reference to the drawings. Figure 4 is a vertical cross-sectional view showing the vicinity of the inlet channel 20 of the denitration catalyst polishing apparatus 1, and Figure 5 is an exploded perspective view showing the vicinity of the inlet channel 20.

As shown in Figures 4 and 5, the inflow channel 20 according to this embodiment has an upstream flow path 21 having a bent portion 21a. The abrasive A mixed with air in the mixing section 10 is caused to flow from below the denitration catalyst C through the upstream flow path 21 having the bent portion 21a. With the above configuration, the mixing section 10 and the denitration catalyst C can be arranged side by side. On the other hand, since the upstream flow path 21 has the bent portion 21a, the distribution of the abrasive A flowing into the denitration catalyst C tends to become uneven. However, it is not preferable to provide a long flow path in order to disperse the abrasive A.
In the inflow path 20 of this embodiment, by providing the upstream fixed member 22 with a buffer member and a regulating member as described below, the flow path downstream of the bent portion 21a can be configured compactly and a sufficient dispersion effect of the abrasive A can be obtained.

The upstream fixing member 22 fixes the lower end (upstream end) of the denitration catalyst C, and has a linear flow path inside through which the abrasive A mixed with air flows. As shown in Figures 4 and 5, the flow path direction of the upstream fixing member 22 is the same as the flow path direction of the through hole of the denitration catalyst C. In other words, the flow path direction of the upstream fixing member 22 is approximately perpendicular to the horizontal plane. Within the flow path of the upstream fixing member 22, a buffer member 22a, a first regulating member 22b, and a second regulating member 22c are provided in this order from the top.

The buffer member 22a is a member that reduces the flow rate of the abrasive A mixed with air, and also has the effect of dispersing the abrasive A. The buffer member 22a is made of two mesh members 22a1 and 22a2. The buffer member 22a reduces the flow rate of the abrasive A, thereby suppressing damage to the upstream end of the denitration catalyst C. As shown in FIG. 4, an end face protection material P that abuts against the upstream end of the denitration catalyst C may be further provided. The end face protection material P is made of, for example, a mesh member that corresponds to the shape of the through hole C1 of the denitration catalyst C. By providing such an end face protection material P, damage to the upstream end of the denitration catalyst C can be further suppressed.

The mesh members 22a1 and 22a2 have any opening ratio, mesh number, and mesh size. If the opening ratio is too large, the mesh members are easily damaged, and if it is too small, the pressure loss of the upstream fixing member 22 increases. The opening ratio can be, for example, approximately the same as the opening ratio of the denitration catalyst C. The mesh number and mesh size of the mesh members 22a1 and 22a2 can also be approximately the same as those of the denitration catalyst C.
It is preferable that the openings of the two mesh members 22a1 and 22a2 are arranged so as to be offset from each other in the flow path direction of the upstream fixing member 22. For example, the mesh number of the mesh member 22a1 and the mesh number of the mesh member 22a2 are different from each other, so that the mesh members 22a1 and 22a2 can be arranged so that the openings are offset from each other. For example, the mesh number in the flow path cross section of the mesh member 22a1 can be 21×21, and the mesh number in the flow path cross section of the mesh member 22a2 can be 20×20, which is equal to the number of through holes C1 of the denitration catalyst C. In addition to the above, the mesh members 22a1 and 22a2 may have the same number of meshes and be arranged so that the openings are offset from each other.

The first regulating member 22b is a member having a substantially rectangular parallelepiped shape and is disposed in the center of the flow path cross section of the upstream fixed member 22. Both ends of the first regulating member 22b are fixed in contact with the flow path inner surface of the upstream fixed member 22. In this embodiment, the longitudinal direction of the first regulating member 22b is disposed so as to be perpendicular to the inflow direction of the upstream flow path 21 indicated by the white arrow in Figures 4 and 5. In addition, the lower surface of the first regulating member 22b is disposed so as to be substantially perpendicular to the flow path direction of the upstream fixed member 22.

The second regulating member 22c is arranged at both ends of the flow path cross section of the upstream fixing member 22 and consists of two second regulating members 22c1 and 22c2 having an approximately rectangular parallelepiped shape. Both ends of the second regulating members 22c1 and 22c2 are abutted against the flow path inner surface of the upstream fixing member 22 and fixed. In this embodiment, the longitudinal direction of the second regulating members 22c1 and 22c2 is arranged so as to be perpendicular to the inflow direction of the upstream flow path 21, as shown by the white arrows in Figures 4 and 5. In addition, the second regulating member 22c1 is an outer regulating portion arranged on the outer side of the bent portion 21a of the upstream flow path 21, and the second regulating member 22c2 is an inner regulating portion arranged on the inner side of the bent portion 21a of the upstream flow path 21. The lower surfaces of the second regulating members 22c1 and 22c2 are arranged so as to be approximately perpendicular to the flow path direction of the upstream fixing member 22. The area of the second restricting member 22c1 in the flow passage cross section, i.e., the area of the lower surface, is larger than the area of the lower surface of the second restricting member 22c2. With the above-mentioned configuration, it is possible to preferably disperse the abrasive A which tends to be biased toward the outside of the bent portion 21a.

The first regulating member 22b and the second regulating member 22c regulate and disperse the flow of the abrasive A mixed with the air flowing through the upstream fixed member 22. The first regulating member 22b and the second regulating member 22c may completely block the flow, or may be a member, such as a mesh member, that blocks most of the flow and allows some of it to pass through.

(Polishing and Regeneration Method)
Next, a method for polishing and regenerating the denitration catalyst C using the denitration catalyst polishing apparatus 1 will be described.
The denitration catalyst C with reduced denitration performance, which is the object to be polished by the denitration catalyst polishing device 1, is removed from the denitration device 160 of the coal-fired power plant 100. At this time, the through-holes C1 of the denitration catalyst C may be blocked by coal ash or the like, so the blocked material is removed by air blowing, water washing, or the like as appropriate. Next, the denitration catalyst C is sandwiched between the upstream fixing member 22 and the downstream fixing member 32 to fix the denitration catalyst C. At this time, for example, the side of the denitration catalyst C with more deposits, which was the inlet end of the exhaust gas inlet of the denitration device 160, may be arranged and fixed so that it is located downstream, where the flow rate of the abrasive A is high.

When the denitration catalyst polishing device 1 starts operating, the suction fan 70 and compressor 50 start operating, and the abrasive A mixed with air in the mixing section 10 is sucked upstream. The abrasive A flows into the through hole C1 of the denitration catalyst C through the upstream flow path 21 and the upstream fixing member 22, and after polishing the inner surface of the through hole C1, flows out from the downstream fixing member 32. The abrasive A and the object to be polished that flow out are sucked in by the suction fan 70 together with the air, and flow into the cyclone 40 through the downstream flow path 31. In the cyclone 40, the abrasive A and the object to be polished are separated, and the abrasive A is supplied to the mixing section 10 through the abrasive supply path 33. That is, the abrasive A circulates inside the denitration catalyst polishing device 1. The object to be polished separated in the cyclone 40 is sucked in by the suction fan 70, and flows into the bag filter 60 through the conveying pipe 41 and collected. The air after the objects to be polished have been collected is exhausted to the outside through the exhaust duct 71. The operation of the denitration catalyst polishing device 1 is continued for a predetermined time to polish the inner surface of the through hole C1 of the denitration catalyst C and to remove the deposits and the like adhering to the inner surface of the through hole C1, thereby regenerating the denitration catalyst C.

According to the above-described denitration catalyst polishing apparatus 1 according to the first embodiment, the following effects are achieved.
The denitration catalyst polishing device 1 is configured to have a mixing section 10 arranged upstream of the denitration catalyst C and mixing the abrasive A with air, an inflow passage 20 connecting the mixing section 10 and the denitration catalyst C and through which the abrasive A mixed with air flows, and a suction fan 70 arranged downstream of the denitration catalyst C and sucking the abrasive A and the object to be polished together with air, and the inflow passage 20 is configured to have a buffer member 22a, a first restricting member 22b arranged upstream of the buffer member 22a and in the center of the cross section of the inflow passage 20, and a second restricting member 22c arranged upstream of the first restricting member 22b and at both ends of the cross section of the inflow passage 20. This makes it possible to reduce the flow rate of the abrasive A mixed with air by the buffer member 22a. In addition, the first restricting member 22b and the second restricting member 22c can disperse the abrasive A mixed with air, so that the denitration catalyst C can be polished uniformly.

The inflow passage 20 is arranged upstream of the denitration catalyst C, and has an upstream fixed member 22 whose flow path direction is the same as the flow path direction of the through hole of the denitration catalyst C, and an upstream flow path 21 arranged upstream of the upstream fixed member 22 and having a bent portion 21a, and a buffer member 22a, a first regulating member 22b, and a second regulating member 22c are provided within the flow path of the upstream fixed member 22. As a result, even if the inflow passage 20 has a bent portion, the abrasive A can be dispersed to uniformly polish the denitration catalyst C.

The first and second restricting members 22b and 22c are arranged so that their longitudinal directions are perpendicular to the inflow direction of the upstream flow path 21. This makes it possible to preferably obtain the effect of dispersing the abrasive A when the upstream flow path 21 has a bent portion 21a.

The area of the outer regulating portion 22c1 in the cross section of the flow path is larger than the area of the inner regulating portion 22c2 in the cross section of the flow path. This makes it possible to more effectively disperse the abrasive A when the upstream flow path 21 has a bent portion 21a.

The buffer member 22a is configured as two mesh members 22a1 and 22a2, and the openings of the mesh members 22a1 and 22a2 are arranged at positions offset from each other in the flow path direction. This makes it more likely that the abrasive A will collide with one of the two mesh members 22a1 and 22a2, reducing the flow rate and dispersing the abrasive A, thereby preferably reducing the flow rate of the abrasive A and dispersing the abrasive A.

Second Embodiment
A denitration catalyst polishing apparatus 1A according to a second embodiment will be described with reference to the drawings. Hereinafter, description of the same configuration as in the first embodiment may be omitted.
6 is an exploded perspective view showing the configuration of the inflow passage 20 of the denitration catalyst polishing apparatus 1A according to this embodiment. The configuration of this embodiment other than the inflow passage 20 is the same as that of the first embodiment.

As shown in Fig. 6, the inflow path 20 is composed of an upstream flow path 21 and an upstream fixing member 22, similar to the first embodiment. The upstream flow path 21 has a bent portion 21a. The upstream fixing member 22 has a buffer member 22a, a first regulating member 22b, and a second regulating member 22c. The buffer member 22a is composed of two mesh members 22a1 and 22a2, similar to the first embodiment.

The first restricting member 22b is a member having a substantially rectangular parallelepiped shape and located in the center of the cross section of the flow path, as in the first embodiment. The lower surface of the first restricting member 22b is located so as to be substantially perpendicular to the flow path direction of the upstream fixing member 22.

The second regulating member 22c is composed of the second regulating members 22c3 and 22c4, and is a member having a substantially rectangular parallelepiped shape arranged at both ends of the flow path cross section, as in the first embodiment. The lower surfaces of the second regulating members 22c1 and 22c2 are arranged so as to be substantially perpendicular to the flow path direction of the upstream fixing member 22.

In this embodiment, the longitudinal direction of the first regulating member 22b and the second regulating member 22c is arranged to be parallel to the inflow direction of the upstream flow passage 21, as shown by the outlined arrow in Figure 6. In addition, the areas of the second regulating member 22c3 and the second regulating member 22c4 in the cross section of the flow passage are approximately the same.

The first regulating member 22b and the second regulating member 22c of the second embodiment described above also preferably provide the effect of dispersing the abrasive A mixed with air.

Other Embodiments
A denitration catalyst polishing apparatus 1B according to this embodiment will be described with reference to the drawings. Hereinafter, description of the same configuration as in the first and second embodiments may be omitted.
FIG. 7 is a perspective view showing the configuration of the Denitration catalyst C fixed to the Denitration catalyst polishing apparatus 1B according to this embodiment, and the upstream side fixing member 22, the downstream side fixing member 32 and the vicinity thereof.

The denitration catalyst polishing apparatus 1B according to this embodiment has rotation mechanisms R1 and R2, as shown in FIG. 7. The rotation mechanisms R1 and R2 support the denitration catalyst C rotatably around the flow direction of the through hole C1 of the denitration catalyst C as an axis. As described above, when the upstream flow path 21 in the inflow path 20 has a bent portion 21a, the distribution of the abrasive A flowing from the inflow path 20 into the denitration catalyst C may become biased. In the denitration catalyst polishing apparatus 1B according to this embodiment, the denitration catalyst C is rotated by the rotation mechanisms R1 and R2 while being polished. As a result, even if the distribution of the abrasive A flowing into the denitration catalyst C becomes biased due to the shape of the inflow path 20, the inner surface of the through hole of the denitration catalyst C can be polished uniformly.

The rotation mechanisms R1 and R2 have a drive unit such as a motor and can rotate the denitration catalyst C. The number of rotations of the denitration catalyst C is not particularly limited, but for example, when the time required to polish the denitration catalyst C is T, it is preferable to set the rotation angle at time T to 360 degrees x n. However, this is not the case when the rotation angle at the time T is sufficiently large. In addition, the rotation mechanisms R1 and R2 may rotate the denitration catalyst C constantly, or may rotate the denitration catalyst C by a predetermined angle every time a certain time has passed. For example, the rotation mechanisms R1 and R2 can be configured so that the rotation angle of the denitration catalyst C at time T is 360 degrees and the denitration catalyst C is rotated by 90 degrees every time 1/4T has passed.

As shown in Figure 7, the rotation mechanism R1 is disposed between the upstream fixed member 22 and the denitration catalyst C. Similarly, the rotation mechanism R2 is disposed between the downstream fixed member 32 and the denitration catalyst C. The structure of the rotation mechanisms R1 and R2 is not particularly limited as long as they can rotatably support the denitration catalyst C.

The present invention is not limited to the above embodiments and can be modified as appropriate.

Although the buffer member 22a according to the first embodiment has been described as being composed of two mesh members 22a1 and 22a2, this configuration is not limiting. The buffer member 22a may be composed of three or more mesh members. In this case, it is preferable that the openings of at least one pair of mesh members are positioned at positions offset from each other in the flow path direction.

The first and second regulating members 22b and 22c in the above embodiment have been described as having a substantially rectangular parallelepiped shape and being arranged so that the lower surfaces are substantially perpendicular to the flow path direction of the upstream fixed member 22, but are not limited to this configuration. The first and second regulating members 22b and 22c may have a shape other than a rectangular parallelepiped. Also, the lower surfaces may be inclined rather than perpendicular to the flow path direction of the downstream fixed member 22. Also, the angle of the first and second regulating members 22b and 22c with respect to the flow path direction may be configured to be changeable.

The rotation mechanisms R1 and R2 according to the other embodiments described above may be combined with the configuration of the upstream fixing member 22 according to the first or second embodiment. This allows the denitration catalyst C to be polished more uniformly.

1 Denitration catalyst polishing device 10 Mixing section 20 Inflow passage 21 Upstream side flow passage 22 Upstream side fixing member 22a Cushioning member 22a1 Mesh member 22a2 Mesh member 22b First restricting member 22c Second restricting member 70 Suction fan (suction section)
C Denitrification catalyst C1 through hole

Claims (2)

A denitration catalyst polishing apparatus for polishing an inner surface of a denitration catalyst having a plurality of through holes extending in a longitudinal direction, the apparatus comprising:
A mixing section disposed upstream of the denitration catalyst and configured to mix an abrasive with air;
an inlet passage disposed between the mixing section and the denitration catalyst, through which the abrasive mixed with air flows;
a suction section that is disposed downstream of the denitration catalyst and that sucks in the abrasive and the object to be polished together with air;
The inlet passage includes a buffer member for reducing the flow rate of the abrasive mixed with the air,
a first restricting member disposed upstream of the buffer member and at a center of the inlet passage in a cross section;
a second restricting member disposed upstream of the first restricting member and at both ends of the inlet passage in a cross section of the inlet passage,
the inflow passage includes an upstream fixing member that fixes the denitration catalyst, and an upstream flow passage that is disposed upstream of the upstream fixing member and has a bent portion,
a flow path direction of the upstream fixing member is the same as a flow path direction of the through hole,
the buffer member, the first regulating member, and the second regulating member are disposed in a flow path of the upstream fixed member,
the first regulating member and the second regulating member have a substantially rectangular parallelepiped shape and are arranged such that a longitudinal direction thereof is perpendicular to an inflow direction of the upstream flow passage,
The buffer members are composed of two or more members, and openings of at least one set of the buffer members are arranged at positions shifted from each other in the flow path direction. the second restricting member includes an outer restricting portion disposed on an outer side of the bent portion and an inner restricting portion disposed on an inner side of the bent portion,
2. The apparatus for polishing a denitration catalyst according to claim 1, wherein an area of the outer regulating portion in a cross section of the flow passage is larger than an area of the inner regulating portion in a cross section of the flow passage.

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