The present invention relates to an exhaust gas treatment device that reduces nitrogen oxides in exhaust gas discharged from a coal-fired boiler by a denitration device.
Background technology
[0002]
　In order to remove the coal fired power nitrogen oxides in the combustion flue gas for power generation boiler (NOx), a reducing agent in the exhaust gas (e.g., ammonia) was injected, the NOx N denitration catalyst 2 is denitrator be reduced to An exhaust gas treatment device that is generally adopted and guides exhaust gas discharged from a coal-fired boiler to a denitration device via a horizontal duct and a vertical duct is known. In addition, if dust or ash (hereinafter collectively referred to as ash particles) generated by combustion of coal flies to the denitration device together with the exhaust gas, it may accumulate on the catalyst layer and hinder the flow of the exhaust gas. An exhaust gas treatment device that collects the ash particles inside the ash particles upstream of the denitration device has been proposed.
[0003]
　For example, Patent Document 1 includes a horizontal duct connected to an exhaust gas outlet of a coal-fired boiler, a vertical duct connected to the horizontal duct, and a hopper provided below a connection portion between the horizontal duct and the vertical duct. Exhaust gas treatment equipment is described. Ash particles (dust or ash produced by combustion) in the exhaust gas flowing through the horizontal duct are collected by the hopper.
[0004]
　Further, in the same document, a collision plate for collecting large particle size ash particles accompanying the exhaust gas, which is unevenly distributed in the lower part of the horizontal duct, is provided at the upper end opening of the hopper, and the ash in the exhaust gas is provided in the collision plate. It is described that the particles collide and fall into the hopper.
Prior art literature
Patent documents
[0005]
Patent Document 1: Japanese Unexamined Patent Publication No. 2016-198701
Outline of the invention
Problems to be solved by the invention
[0006]
　For example, when coal having a large ash content such as coal produced in India is used, the exhaust gas contains a large amount of ash particles having a large particle size (100 μm or more). When coal having a large amount of ash is used as described above, the collision plate described in Patent Document 1 is provided to improve the collection rate of ash particles having a large particle size by the hopper and suppress the wear of the denitration catalyst of the denitration device. be able to.
[0007]
　However, in the device of Patent Document 1, a collision plate must be provided so as to cross the upper end opening of the hopper, which may lead to an increase in the flow resistance of the exhaust gas. In addition, reinforcement may be required to suppress vibration noise.
[0008]
　Therefore, an object of the present invention is to provide an exhaust gas treatment apparatus capable of improving the collection rate of ash particles having a large particle size while suppressing an increase in the flow resistance of the exhaust gas.
Means to solve problems
[0009]
　In order to achieve the above object, the present invention is an exhaust gas treatment device that reduces nitrogen oxides in exhaust gas discharged from a coal-fired boiler by a denitration device, and includes a duct and a hopper. The duct has a horizontal duct extending in a substantially horizontal direction and a vertical duct extending in a substantially vertical direction. The front end of the horizontal duct communicates with the exhaust gas outlet of the coal-fired boiler, and the rear end of the horizontal duct communicates with the lower end of the vertical duct. The duct partitions the space inside the duct that allows the exhaust gas discharged from the coal-fired boiler to flow from the horizontal duct to the upper part of the vertical duct and leads to the denitration device. The hopper is provided below the vertical duct and communicates with the space inside the duct through the opening at the upper end of the hopper.
[0010]
　The exhaust gas treatment device according to the first aspect of the present invention includes a plurality of striking collision plates. A plurality of striking collision plates extend forward continuously from the front end edge of the upper end opening of the hopper, are fixed to the bottom surface of the duct that divides the lower part of the space inside the duct, and stand upright. Line up in a line along the crossing direction.
[0011]
　In order to improve the collection rate of large particle size ash particles while suppressing the increase in the flow resistance of the exhaust gas, it is preferable that the standing direction of the striking collision plate with respect to the bottom surface of the duct is substantially perpendicular to the bottom surface of the duct. The amount of protrusion (protrusion height) of the striking collision plate from the above is preferably 10 to 15% of the width in the height direction of the horizontal duct. Further, the position of the striking collision plate is preferably on the rear side (the hopper upper end opening side) of the bottom surface of the duct from the center in the front-rear direction, and more preferably 1 to 1.5 m from the front end edge of the hopper upper end opening. be.
[0012]
　In the above configuration, a striking collision plate is provided on the bottom surface of the duct, so that large particle size ash particles unevenly distributed in the lower part of the horizontal duct and accompanied by the exhaust gas collide with the striking collision plate to collide with the hopper. It is possible to improve the collection rate of large particle size ash particles while suppressing an increase in the flow resistance of exhaust gas.
[0013]
　The exhaust gas treatment device of the second aspect of the present invention includes an inclined collision plate. The inclined collision plate extends continuously upward from the rear end edge of the upper end opening of the hopper, is fixed to the rear surface of the duct that partitions the rear of the duct inner space, and extends inclined from the rear surface to the front and lower sides.
[0014]
　In order to improve the collection rate of large particle size ash particles while suppressing the increase in the flow resistance of exhaust gas, the amount of protrusion of the inclined collision plate from the rear surface of the duct is the depth length of the vertical duct (front and front). 5 to 15% of the distance from the rear surface) is preferable.
[0015]
　In the above configuration, a simple configuration in which an inclined collision plate is provided on the rear surface of the duct causes large particle size ash particles that are unevenly distributed in the lower part of the horizontal duct and accompany the exhaust gas to collide with the lower surface of the inclined collision plate to cause a hopper. It is possible to improve the collection rate of large particle size ash particles while suppressing an increase in the flow resistance of exhaust gas.
[0016]
　A third aspect of the present invention is the exhaust gas treatment device of the first or second aspect, which includes a plurality of guide vanes and an inclined collision surface. The plurality of guide vanes are arranged in the space inside the duct above the hopper, are fixed to the duct and overlap each other in a state of being separated from each other, and guide the exhaust gas flowing from the horizontal duct to the vertical duct vertically upward. The inclined collision surface is fixedly provided at the end of the lowermost guide vane on the horizontal duct side among the plurality of guide vanes, and extends so as to be inclined rearward and downward.
[0017]
　In the above configuration, the inclined collision surface is fixedly provided on the lowermost guide vane, so that the large particle size ash particles unevenly distributed in the lower part of the horizontal duct and accompanied by the exhaust gas collide with the inclined collision surface. It can be collected by the hopper, and the collection rate of large particle size ash particles is further improved.
The invention's effect
[0018]
　According to the present invention, it is possible to suppress an increase in the flow resistance of exhaust gas, improve the collection rate of ash particles having a large particle size, and suppress wear of a denitration catalyst due to the ash particles having a large particle size.
A brief description of the drawing
[0019]
FIG. 1 is an overall configuration diagram of an exhaust gas treatment device according to a first embodiment of the present invention.
FIG. 2 is an enlarged view of a main part of FIG.
3 is a perspective view of the countersunk collision plate of FIG. 2. FIG.
FIG. 4 is an enlarged view of the strut-shaped collision plate of FIG.
5 is an enlarged view of the inclined collision plate of FIG. 2. FIG.
[Fig. 6] Fig. 6 is a diagram showing a modified example of a countersunk collision plate.
[Fig. 7] Fig. 7 is a diagram showing a modified example of an inclined collision plate, in which (a) shows an example in which it is arranged in two stages, and (b) shows an example in which it has a curved plate shape.
[Fig. 8] Fig. 8 is a diagram showing a recovery rate of ash particles in a comparative example.
FIG. 9 is a diagram showing a recovery ratio of ash particles of the first embodiment.
FIG. 10 is a diagram showing a recovery rate of ash particles of the second embodiment.
FIG. 11 is a diagram showing a recovery ratio of ash particles of the third embodiment.
FIG. 12 is a diagram showing a flow of exhaust gas according to the third embodiment.
FIG. 13 is a diagram showing a flow of ash particles having a large particle size in Example 3.
FIG. 14 is a diagram showing a guide vane protector according to a second embodiment of the present invention.
[Fig. 15] Fig. 15 is a diagram showing a modified example of the guide vane protector.
Mode for carrying out the invention
[0020]
　The exhaust gas treatment device according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. In the following, the upstream side and the downstream side (left side and right side in FIG. 2) in the exhaust gas flow direction in the horizontal duct 8 will be described as the front side and the rear side.
[0021]
　As shown in FIG. 1, the coal-fired boiler 1 includes a burner 4 that burns coal 2 crushed by a crusher (not shown) such as a mill with a combustion gas 3. A plurality of heat recovery heat transfer tubes 5 through which water flows are provided in the furnace and the exhaust gas flow path of the coal-fired boiler 1, and heat recovery heat transfer tubes are provided in the exhaust gas flow path on the downstream side of the coal-fired boiler 1. One economizer (coal saver) 6 is provided. As a result, the coal-fired boiler 1 generates steam for driving a power generation turbine (not shown).
[0022]
　The exhaust gas outlet 7 of the coal-fired boiler 1 is provided on the side wall of the boiler below the economizer 6, and the front end (upstream end) of the horizontal duct 8 is connected to the exhaust gas outlet 7 in a communicating state. The horizontal duct 8 has a rectangular tubular shape extending substantially horizontally, and the rear end (downstream end) of the horizontal duct 8 is connected to the vertical duct 9 in a communicating state. The vertical duct 9 has a rectangular tubular shape extending in a substantially vertical direction, and the upper end of the vertical duct 9 is connected to the inlet duct 10a of the denitration device 10. The horizontal duct 8 and the vertical duct 9 form a duct 17, and the duct 17 distributes the exhaust gas generated by burning coal in the coal-fired boiler 1 from the exhaust gas outlet 7 to the upper side of the vertical duct 9 via the horizontal duct 8. The space 18 in the duct leading to the top of the denitration device 10 is partitioned. The inside of the denitration device 10 is filled with the denitration catalyst 10b, and ammonia is injected as a reducing agent from the ammonia supply nozzle 10c provided in the middle of the vertical duct 9. As a result, the denitration device 10 reduces and discharges nitrogen oxides (NOx) contained in the exhaust gas. The NOx-removed exhaust gas discharged from the denitration device 10 is discharged from the chimney 14 into the atmosphere through the air heater 11 for heating the combustion gas, the dust collector 12, and the desulfurization device 13.
[0023]
　A rear hopper (hopper) 15 that communicates with the duct inner space 18 (horizontal duct 8 and vertical duct 9) via a rectangular hopper upper end opening 19 is provided substantially vertically below the vertical duct 9. The upstream inner surface of the rear hopper 15 is inclined rearward and downward from the front end edge of the hopper upper end opening 19. Further, below the coal-fired boiler 1, a front hopper 16 communicating with the inside of the boiler and the horizontal duct 8 is provided. Ash particles in the exhaust gas fall and are collected on the front hopper 16 and the rear hopper 15.
[0024]
　As shown in FIG. 2, of the duct inner space 18, the upstream space extending substantially horizontally rearward from the exhaust gas outlet 7 (see FIG. 1) is a pair of side surfaces 24 (in FIG. 2), the ceiling surface 22 and the bottom surface 23. The downstream space, which is partitioned by (shown only one) and extends substantially vertically upward from the rear end of the upstream space, is a pair of side surfaces 27 with a front surface 25 and a rear surface 26 (only one is shown in FIG. 2). ) And. The bottom surface 23 that partitions the lower part of the upstream space of the duct inner space 18 extends continuously forward from the front end edge 20 of the hopper upper end opening 19, and the rear surface 26 that partitions the rear of the downstream side space of the duct inner space 18 has a rear surface 26. It extends continuously upward from the rear end edge 21 of the hopper upper end opening 19.
[0025]
　A plurality of (four in the example of FIG. 2) guide vanes 28 are provided in the duct inner space 18 above the rear hopper 15 (hopper upper end opening 19). The guide vanes 28 are curved plate-like bodies that are curved so as to bulge rearward and downward from the vicinity of the rear end of the horizontal duct 8 and extend rearward and upward, and are arranged so as to be vertically overlapped with each other in a state of being separated from each other. A rod-shaped or tubular guide fixing member 29 is fixed to the upper and lower edges of each guide vane 28 by welding, and both ends of each guide fixing member 29 are a pair of side surfaces 24 on the upstream side or a downstream side of the duct 17. It is fixed to a pair of side surfaces 27 by welding. The guide vanes 28 are provided over substantially the entire length direction (duct width direction) of the guide fixing member 29. In this way, each of the guide vanes 28 is fixed to the duct 17 above the rear hopper 15 and guides the exhaust gas flowing from the horizontal duct 8 to the vertical duct 9 vertically upward.
[0026]
　As shown in FIGS. 2 to 4, a plurality of (three in this embodiment) rectangular flat plate-shaped strut-shaped collision plates 31 are provided on the bottom surface 23 of the duct 17. The bottom surface 23 on which the striking collision plate 31 is provided may be the bottom surface of the horizontal duct 8, or may be the bottom surface of the connecting portion between the horizontal duct 8 and the vertical duct 9 on the vertical duct 9 side.
[0027]
　The plurality of striking collision plates 31 are fixed to the bottom surface 23 of the duct 17 and stand upright, and are linearly arranged along the direction intersecting the flow direction (front-back direction) of the exhaust gas in a state of being separated from each other. The striking collision plates 31 of the present embodiment are arranged in a straight line along a direction substantially orthogonal to the flow direction of the exhaust gas. The striking collision plate 31 has a rod-shaped or tubular collision plate fixing member 32 welded to the bottom surface 23 (welded portion 33), and the striking collision plate 31 welded to the front side of the collision plate fixing member 32 (welded portion 34). Is fixed to the bottom surface 23 by. The number of striking collision plates 31 is not limited to three and is arbitrary.
[0028]
　In order to improve the collection rate of large particle size ash particles by the rear hopper 15 while suppressing the increase in the flow resistance of the exhaust gas, the countersunk collision plate 31 stands up substantially perpendicular to the bottom surface 23, and the bottom surface 23 The protrusion amount (protrusion height) H1 of the striking collision plate 31 from the above is set to 10 to 15% of the width (vertical distance from the bottom surface 23 to the ceiling surface 22) H2 in the height direction of the horizontal duct 8. The position L1 on the front surface of the countersunk collision plate 31 is on the rear side (the hopper upper end opening 19 side) of the bottom surface 23 from the center in the front-rear direction, and is 1 to 1.5 m from the front end edge 20 of the hopper upper end opening 19. Is set to.
[0029]
　In the striking collision plate 31A inclined forward and downward as shown by the two-point chain line in FIG. 4, ash particles tend to stay in the space 35 between the striking collision plate 31A and the bottom surface 23 and become a flow resistance of exhaust gas. In the striking collision plate 31B inclined rearward and upward as shown by the broken line in FIG. 4, the upper surface of the striking collision plate 31B guides the ash particles upward so as to be away from the rear hopper 15, so that the striking collision plate 31 The standing direction is preferably substantially perpendicular to the bottom surface 23. Further, if the protruding height H1 of the striking collision plate 31 is excessive (too high), the flow resistance of the exhaust gas increases, and if it is too small (too low), the effect of collecting ash particles having a large particle size is significantly improved. Therefore, the protrusion height H1 of the striking collision plate 31 is preferably in the above range.
[0030]
　Further, among the plurality of striking collision plates 31, the striking collision plates 31 located at both ends are arranged apart from the side surface 24 of the duct 17. This is because when the striking collision plate 31 is in contact with the side surface 24, ash particles stay between the striking collision plate 31 and the side surface 24 and become a flow resistance of exhaust gas.
[0031]
　As shown in FIGS. 2 and 5, a rectangular flat plate-shaped inclined collision plate 36 is fixed to the lower portion of the rear surface 26 of the duct 17 (the lower portion of the rear surface of the vertical duct 9). The inclined collision plate 36 is formed by welding a rod-shaped or tubular collision plate fixing member 37 to the rear surface 26 (welded portion 38) and welding the inclined collision plate 36 to the rear surface 26 and the collision plate fixing member 37 (welded portion 39). It is fixed to the rear surface 26. The inclined collision plate 36 is arranged behind the guide vane 28 over substantially the entire area in the duct width direction, and extends from the rear surface 26 so as to be inclined forward and downward.
[0032]
　In order to improve the collection rate of large particle size ash particles by the rear hopper 15 while suppressing the increase in the flow resistance of the exhaust gas, the protrusion amount L3 of the inclined collision plate 36 from the rear surface 26 of the duct 17 is the vertical duct 9. The depth length (distance between the front surface 25 and the rear surface 26) is set to 5 to 15% of L4.
[0033]
　As shown by the two-dot chain line in FIG. 5, in the inclined collision plate 36A protruding substantially horizontally, ash particles are accumulated on the upper surface, and it is necessary to reinforce the inclined collision plate 36A due to the ascending current. As shown by, in the inclined collision plate 36B which is excessively inclined and the amount of protrusion from the rear surface 26 is small, it is difficult for the ash particles to come into contact with the inclined collision plate 36B. It is preferable to incline to.
[0034]
　In the present embodiment, the striking collision plates 31 are arranged in one row, but as shown in FIG. 6, the striking collision plates 31 may be arranged in a plurality of rows (two rows in the example of FIG. 6) in a staggered manner. good.
[0035]
　Further, in the present embodiment, the flat plate-shaped inclined collision plates 36 are arranged in one stage, but as shown in FIG. 7A, the inclined collision plates 36 are arranged in a plurality of stages at different heights (2 in the example of FIG. 7A). It may be arranged in each stage), and the amount of protrusion of the inclined collision plate 36 from the rear surface 26 may be different between each stage (for example, in the case of two stages, the upper stage and the lower stage). Further, as shown in FIG. 7B, a curved plate-shaped inclined collision plate 40 having a convex upper surface may be used.
[0036]
　Next, a case where the coal-fired boiler 1 is operated using the coal 2 having a high ash content and a quality that is difficult to be finely pulverized will be described.
[0037]
　In the operation of the coal-fired boiler 1, the coal 2 and the combustion gas (air) 3 are supplied to the coal-fired boiler 1 to the burner 4 to burn the coal. The heat generated by the combustion reaction of coal heats the water flowing through the heat recovery heat transfer tube 5 and the economizer 6 to generate steam, which is then generated by a turbo generator.
[0038]
　Since the coal 2 burned by the coal-fired boiler 1 has a large amount of ash and has a quality that is difficult to be finely pulverized, the exhaust gas contains a large amount of ash having a particle size (diameter) of 100 μm or more, and the coal 2 is burned. The exhaust gas generated by the above is discharged from the exhaust gas outlet 7. The ash particles having a large particle size (diameter of 100 μm or more) in the discharged exhaust gas sink to the bottom of the horizontal duct 8 while flowing through the horizontal duct 8, and flow unevenly at the bottom. Then, a part of the large particle size ash particles unevenly distributed in the lower part of the horizontal duct 8 and accompanied by the exhaust gas collides with the striking collision plate 31 standing up from the bottom surface 23 of the duct 17 upstream of the rear hopper 15. The flow velocity decreases and it falls on the rear hopper 15. Further, some of the large particle size ash particles that do not fall from the bottom surface 23 of the duct 17 onto the rear hopper 15 but are guided by the guide vanes 28 and move upward in the vertical duct 9 collide with the inclined collision plate 36. Then it falls on the rear hopper 15. As described above, the large particle size ash particles in the exhaust gas are efficiently collected in the rear hopper 15 by the striking collision plate 31 and the inclined collision plate 36, and most of them are removed from the exhaust gas.
[0039]
　The exhaust gas from which most of the large particle size ash particles have been removed is guided to the denitration catalyst 10b after ammonia is supplied from the ammonia supply nozzle 10c, and NOx in the exhaust gas is reduced while passing through the denitration catalyst 10b. It is decomposed into nitrogen and water. As described above, most of the large particle size ash particles in the exhaust gas are removed before passing through the denitration catalyst 10b, so that the wear of the denitration catalyst 10b can be suppressed. Then, the exhaust gas that has passed through the denitration catalyst 10b exchanges heat with the combustion air in the air heater 11 to become low temperature, the ash particles are removed by the dust collector 12, the sulfur oxides are removed by the desulfurization device 13, and then the chimney. It is released into the air from 14.
[0040]
　Next, the effect of collecting ash particles having a large particle size by the striking collision plate 31 and the inclined collision plate 36 will be described with reference to FIGS. 8 to 13. In FIGS. 8 to 11, the front hopper 16 is referred to as a hopper 1 and the rear hopper 15 is referred to as a hopper 2.
[0041]
　8 to 11 show the recovery ratio (collection rate%) of ash particles for each particle size (37 μm, 65 μm, 115 μm, 200 μm, 360 μm) by the front hopper (hopper 1) 16 and the rear hopper (hopper 2) 15. This is the result obtained by analysis. In FIG. 8 (Comparative Example 1), when both the striking collision plate 31 and the inclined collision plate 36 are not provided, FIG. 9 (Example 1) does not provide the inclined collision plate 36 and a row of striking collisions is provided. When the plate 31 is provided, FIG. 10 (Example 2) shows one row of the flat plate-shaped one-stage inclined collision plate 36 without the strut-shaped collision plate 31. It is each result when the siding collision plate 31 and the flat plate-shaped one-stage inclined collision plate 36 are provided. Further, FIG. 12 analyzes the flow of exhaust gas from the exhaust gas outlet 7 to the denitration catalyst 10b in the case of Example 3 (providing a single row of striking collision plates 31 and a flat plate-shaped one-stage inclined collision plate 36). As a result, FIG. 13 is a result of analyzing the flow of ash particles having a large particle size (360 μm) from the exhaust gas outlet 7 to the denitration catalyst 10b in the case of Example 3.
[0042]
　From FIGS. 8 to 11, the collection rate of large particle size ash particles by the rear hopper 15 is improved by providing the striking collision plate 31 and the tilting collision plate 36, and only the striking collision plate 31 or the tilted collision. It can be seen that the collection rate is improved even when only the plate 36 is provided. Further, from FIGS. 12 and 13, it can be seen that the rear hopper 15 can satisfactorily collect ash particles having a large particle size while suppressing the turbulence of the exhaust gas flow (increased flow resistance).
[0043]
　As described above, according to the present embodiment, it is possible to improve the collection rate of ash particles having a large particle size while suppressing an increase in the flow resistance of the exhaust gas.
[0044]
　In the embodiment shown in FIG. 1, the case where both the striking collision plate 31 and the inclined collision plate 36 are provided has been described, but only one of these may be provided.
[0045]
　Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the inclined collision surface 41 is added to the first embodiment, and other configurations are common to the first embodiment. Therefore, the description overlapping with the first embodiment will be omitted.
[0046]
　As shown in FIG. 14, at the lower end of the guide vane 28 (the end on the horizontal duct 8 side), the guide vanes are arranged over substantially the entire area in the duct width direction and cover the front and the bottom of the guide fixing member 29. The protector 42 is fixed. The guide vane protector 42 is a plate material having an L-shaped cross section, and has a flat plate-shaped protector front plate portion 43 that inclines forward and downward in front of the guide fixing member 29 and a flat plate-shaped protector front plate portion 43 that inclines backward and downward from the lower end edge of the protector front plate portion 43. It integrally has a flat plate-shaped protector lower plate portion 44 extending vertically. The protector lower plate portion 44 is fixed to the guide vane 28 via the support 45.
[0047]
　The protector lower plate portion 44 of the guide vane protector 42 fixed to the lowermost guide vane 28A (see FIG. 2) among the plurality of guide vanes 28 has a protector extension extending rearward and downward beyond the joint position with the support 45. A portion 46 is provided. The lower surface (front surface) of the protector lower plate portion 44 including the protector extension portion 46 is fixedly provided at the lower end portion of the lowermost guide vane 28A and constitutes an inclined collision surface 41 extending rearward and downwardly.
[0048]
　The shape of the guide vane protector 42 is not limited to the above, and other shapes (for example, as shown in FIG. 15, a semicircular protector front plate portion 47 curved along the outer surface on the front side of the guide fixing member 29) , A J-shaped cross section integrally having a flat plate-shaped protector lower plate portion 44 extending rearwardly and downwardly from the lower end edge of the protector front plate portion 47) may be used.
[0049]
　According to the present embodiment, due to a simple configuration in which the inclined collision surface 41 is fixedly provided at the lower end of the lowermost guide vane 28A, the large particle size is unevenly distributed in the lower part of the horizontal duct 8 and is accompanied by the exhaust gas. The ash particles can be made to collide with the inclined collision surface 41 and collected in the rear hopper 15, and the collection rate of the ash particles having a large particle size is further improved.
[0050]
　The present invention is not limited to the above-described embodiments and modifications described as examples, and is not limited to the above-described embodiments and the like as long as it does not deviate from the technical idea of ​​the present invention. , Various changes are possible depending on the design and the like.
Code description
[0051]
1: Coal-fired boiler
2: Coal
7: Exhaust gas outlet
8: Horizontal duct
9: Vertical duct
15: Rear hopper (hopper)
16: Front hopper
17: Duct
18: Duct inner space
19: Hopper upper end opening
20: Hopper upper end opening Front edge
21: Rear edge of hopper upper end opening
23: Bottom surface of duct
26: Rear surface of duct
28: Guide vane
28A: Bottom guide vane
31: Tactile collision plate
36, 40: Inclined collision plate
41: Inclined collision surface
The scope of the claims
[Claim 1]
　An exhaust gas treatment device that reduces nitrogen oxides in exhaust gas discharged from a coal-fired boiler by a denitration device, and has a
　horizontal duct extending in a substantially horizontal direction and a vertical duct extending in a substantially vertical direction. The front end communicates with the exhaust gas outlet of the coal-fired boiler, the rear end of the horizontal duct communicates with the lower end of the vertical duct, and the exhaust gas discharged from the coal-fired boiler flows from the horizontal duct to the upper part of the vertical duct. A duct that divides the space inside the duct that leads to the denitration device
　, a hopper that is provided below the vertical duct and communicates with the space inside the duct via the upper end opening of the hopper, and
　continuous from the front end edge of the upper end opening of the hopper. A plurality of thrusters that extend forward and stand up at the bottom surface of the duct that partitions the lower part of the space inside the duct, and are linearly arranged along the direction of intersection with the flow direction of the exhaust gas in a state of being separated from each other.
　An exhaust gas treatment device including a collision plate .
[Claim 2]
　An exhaust gas treatment device that reduces nitrogen oxides in exhaust gas discharged from a coal-fired boiler by a denitration device, and has a
　horizontal duct extending in a substantially horizontal direction and a vertical duct extending in a substantially vertical direction. The front end communicates with the exhaust gas outlet of the coal-fired boiler, the rear end of the horizontal duct communicates with the lower end of the vertical duct, and the exhaust gas discharged from the coal-fired boiler flows from the horizontal duct to the upper part of the vertical duct. From the duct that divides the space inside the duct leading to the denitration device
　, the hopper provided below the vertical duct and communicating with the space inside the duct via the upper end opening of the hopper, and
　the rear end edge of the upper end opening of the hopper.
　An exhaust gas treatment device comprising: an inclined collision plate which is fixed to a rear surface of the duct which continuously extends upward and partitions a rear portion of the space inside the duct, and which extends incline from the rear surface to the front and lower sides .
[Claim 3]
　The exhaust gas treatment device according to claim 1 or 2, which
　is arranged in the duct inner space above the hopper, is fixed to the duct and overlaps vertically in a state of being separated from each other, and is said to be above the horizontal duct. A plurality of guide vanes that guide the exhaust gas flowing into the vertical duct vertically upward, and a plurality of guide vanes
　fixedly provided at the end of the lowermost guide vane on the horizontal duct side, and inclined rearward and downward.
　An exhaust gas treatment device including an inclined collision surface extending vertically .