WO2019168059A1

WO2019168059A1 - Exhaust gas treatment device

Info

Publication number: WO2019168059A1
Application number: PCT/JP2019/007658
Authority: WO
Inventors: 谷口　幸久; 勝美矢野
Original assignee: 三菱日立パワーシステムズ株式会社
Priority date: 2018-02-28
Filing date: 2019-02-27
Publication date: 2019-09-06
Also published as: CN111818986A; JP2019147142A

Abstract

The front end of a horizontal duct 8 communicates with an exhaust gas outlet of a coil-fired boiler, and the back end of the horizontal duct 8 communicates with the bottom end of a vertical duct 9. A duct 17 defines a duct inner space 18 which allows exhaust gas emitted from the coil-fired boiler to flow from the horizontal duct 8 to the top of the vertical duct 9, guiding the exhaust gas into a denitration device. A hopper 15 is provided below the vertical duct 9, and communicates with the duct internal space 18 through a hopper upper end opening 19. Multiple screen collision plates 31 extend forwards continuously from the front edge 20 of the hopper upper end opening 19, and are erected on and fixed to the bottom surface 23 of the duct 17 which defines the bottom of the duct inner space 18; in a state separated from each other, the screen collision plates 31 are arranged linearly along a direction crossing the direction of flow of the exhaust gas.

Description

Exhaust gas treatment equipment

The present invention relates to an exhaust gas treatment device that reduces nitrogen oxides in exhaust gas discharged from a coal fired boiler using a denitration device.

In order to remove nitrogen oxide (NOx) in combustion exhaust gas from a coal-fired power generation boiler, a denitration device that injects a reducing agent (for example, ammonia) into the exhaust gas and reduces NOx to N ₂ with a denitration catalyst 2. Description of the Related Art An exhaust gas treatment apparatus that is generally employed and guides exhaust gas discharged from a coal fired boiler to a denitration apparatus via a horizontal duct and a vertical duct is known. In addition, if dust or ash generated by coal combustion (hereinafter collectively referred to as ash particles) fly to the denitration device together with the exhaust gas, it may accumulate on the catalyst layer and hinder the flow of the exhaust gas. There has been proposed an exhaust gas treatment device that collects ash particles therein upstream of a denitration device.

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 at a lower portion of a connection portion between the horizontal duct and the vertical duct. An exhaust gas treatment device is described. Ash particles (dust or ash generated by combustion) in the exhaust gas flowing through the horizontal duct are collected by a hopper.

Further, in the same document, a collision plate for collecting large-sized ash particles that are unevenly distributed in the lower part of the horizontal duct and entrained in the exhaust gas is provided at the upper end opening of the hopper, and the ash in the exhaust gas is provided on the collision plate. It is described that particles collide and fall into a hopper.

JP 2016-198701 A

For example, when coal with a large amount of ash, such as Indian coal, is used, the exhaust gas contains many ash particles with a large particle size (100 μm or more). When using coal with a large amount of ash in this way, the collection rate of ash particles having a large particle diameter by the hopper is improved by providing the collision plate described in Patent Document 1, and the wear of the denitration catalyst of the denitration device is suppressed. be able to.

However, in the apparatus of Patent Document 1, a collision plate must be provided so as to cross the upper end opening of the hopper, which may increase the flow resistance of exhaust gas. In addition, reinforcement for suppressing vibration noise may be necessary.

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 exhaust gas flow resistance.

In order to achieve the above object, the present invention is an exhaust gas treatment device for reducing 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 divides the space in the duct that guides the exhaust gas discharged from the coal fired boiler from the horizontal duct to the upper side of the vertical duct to the denitration apparatus. The hopper is provided below the vertical duct, and communicates with the space in the duct through the hopper upper end opening.

The exhaust gas treatment apparatus according to the first aspect of the present invention includes a plurality of screen-type collision plates. The plurality of screen-like collision plates are fixed to and raised from the front edge of the hopper upper end opening and fixed to the bottom surface of the duct that divides the space under the duct, and in a state of being separated from each other, Line up along the crossing direction.

In order to improve the collection rate of ash particles having a large particle size while suppressing an increase in the flow resistance of exhaust gas, the vertical direction of the screen-like collision plate with respect to the bottom surface of the duct is preferably substantially vertical, and the bottom surface of the duct The projection amount (projection height) of the screen-like collision plate from the top is preferably 10 to 15% of the width in the height direction of the horizontal duct. Further, the position of the screen-like collision plate is preferably the rear side (the hopper upper end opening side) of the duct bottom surface in the front-rear direction, and more preferably 1 to 1.5 m from the front end edge of the hopper upper end opening. is there.

In the above-described configuration, the screen-type collision plate is provided on the bottom surface of the duct, so that the ash particles having a large particle size unevenly distributed in the lower part of the horizontal duct and entrained in the exhaust gas are caused to collide with the screen-type collision plate. 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 exhaust gas.

The exhaust gas treatment apparatus according to 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 hopper upper end opening and is fixed to the rear surface of the duct that defines the rear of the duct internal space, and extends inclined downward from the rear surface.

In order to improve the collection rate of ash particles with a large particle size while suppressing an increase in the flow resistance of the exhaust gas, the protruding amount of the inclined collision plate from the rear surface of the duct is determined by the depth of the vertical duct (front and 5 to 15% of the distance to the rear surface is preferable.

In the above configuration, the inclined collision plate is provided on the rear surface of the duct, so that the ash particles having a large particle size unevenly distributed in the lower part of the horizontal duct and accompanying the exhaust gas are caused to collide with the lower surface of the inclined collision plate to 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 exhaust gas.

A third aspect of the present invention is the exhaust gas treatment apparatus according to the first or second aspect, and includes a plurality of guide vanes and an inclined collision surface. The plurality of guide vanes are disposed in the duct interior space 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 an end portion on the horizontal duct side of the lowermost guide vane among the plurality of guide vanes, and extends obliquely rearward and downward.

In the above configuration, the ash particles with a large particle size that are unevenly distributed in the lower part of the horizontal duct and entrained in the exhaust gas collide with the inclined collision surface by a simple configuration in which the inclined collision surface is fixedly provided on the lowermost guide vane. It can be made to collect by a hopper, and the collection rate of a large particle size ash particle further improves.

According to the present invention, 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 exhaust gas, and to suppress wear of the denitration catalyst due to the ash particles having a large particle size.

1 is an overall configuration diagram of an exhaust gas treatment apparatus according to a first embodiment of the present invention. It is a principal part enlarged view of FIG. It is a perspective view of the screen-shaped collision board of FIG. It is an enlarged view of the screen-shaped collision board of FIG. FIG. 3 is an enlarged view of the inclined collision plate in FIG. 2. It is a figure which shows the modification of a screen-shaped collision board. It is a figure which shows the modification of an inclination collision board, (a) shows the example arrange | positioned in two steps, (b) shows the example made into the curved-plate shape, respectively. It is a figure which shows the collection | recovery ratio of the ash particle of a comparative example. It is a figure which shows the collection | recovery ratio of the ash particle of 1st Example. It is a figure which shows the collection | recovery ratio of the ash particle of 2nd Example. It is a figure which shows the collection | recovery ratio of the ash particle of 3rd Example. It is a figure which shows the flow of the waste gas of Example 3. FIG. 4 is a diagram showing a flow of ash particles having a large particle diameter according to Example 3. It is a figure which shows the guide vane protector which concerns on 2nd Embodiment of this invention. It is a figure which shows the modification of a guide vane protector.

The exhaust gas treatment apparatus according to the first embodiment of the present invention will be described with reference to FIGS. In the following description, the upstream side and the downstream side (the left side and the right side in FIG. 2) of the horizontal duct 8 in the flow direction of the exhaust gas will be described as the front side and the rear side.

As shown in FIG. 1, the coal fired boiler 1 includes a burner 4 that burns coal 2 pulverized by a pulverizer (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 in the exhaust gas flow path on the downstream side of the coal fired boiler 1, a heat recovery heat transfer tube is provided. One economizer (a economizer) 6 is provided. As a result, the coal fired boiler 1 generates steam for driving a power generation turbine (not shown).

The exhaust gas outlet 7 of the coal fired boiler 1 is provided on the boiler side wall 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 cylindrical 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 cylindrical shape extending in a substantially vertical direction, and the upper end of the vertical duct 9 is connected to the inlet duct 10 a of the denitration apparatus 10. The horizontal duct 8 and the vertical duct 9 constitute a duct 17, and the duct 17 distributes 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 through the horizontal duct 8. A duct internal space 18 that leads to the top of the denitration apparatus 10 is defined. The denitration apparatus 10 is filled with a denitration catalyst 10b, and ammonia is injected as a reducing agent from an ammonia supply nozzle 10c provided in the middle of the vertical duct 9. Thereby, the denitration apparatus 10 reduces and discharges nitrogen oxides (NOx) contained in the exhaust gas. The exhaust gas from which NOx discharged from the denitration device 10 is removed is discharged from the chimney 14 into the atmosphere via the air heater 11 that heats the combustion gas, the dust collector 12, and the desulfurization device 13.

A rear hopper (hopper) 15 communicating with the duct internal space 18 (horizontal duct 8 and vertical duct 9) through 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 edge of the hopper upper end opening 19. A front hopper 16 communicating with the inside of the boiler and the horizontal duct 8 is provided below the coal fired boiler 1. In the front hopper 16 and the rear hopper 15, ash particles in the exhaust gas fall and are collected.

As shown in FIG. 2, the upstream space that extends rearward substantially horizontally from the exhaust gas outlet 7 (see FIG. 1) in the duct internal space 18 has a ceiling surface 22, a bottom surface 23, and a pair of side surfaces 24 (FIG. 2). The downstream space which is partitioned by only one side and extends substantially vertically upward from the rear end of the upstream space is a front surface 25, a rear surface 26 and a pair of side surfaces 27 (only one is illustrated in FIG. 2). ). The bottom surface 23 that defines the lower side of the upstream space of the duct internal space 18 extends continuously forward from the front end edge 20 of the hopper upper end opening 19, and the rear surface 26 that defines the rear side of the downstream space of the duct internal space 18 is The hopper upper end opening 19 extends upward continuously from the rear end edge 21.

A plurality of (four in the example of FIG. 2) guide vanes 28 are provided in the duct 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 disposed so as to overlap each other while being separated from each other. A bar-like 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 connected to a pair of side surfaces 24 on the upstream side of the duct 17 or on the downstream side. The pair of side surfaces 27 are fixed by welding. The guide vane 28 is provided over substantially the entire region in the length direction (duct width direction) of the guide fixing member 29. Thus, the guide vanes 28 are each fixed to the duct 17 above the rear hopper 15 and guide the exhaust gas flowing from the horizontal duct 8 to the vertical duct 9 vertically upward.

As shown in FIG. 2 to FIG. 4, a plurality of (three in this embodiment) screen-type collision plates 31 having a rectangular flat plate shape are provided on the bottom surface 23 of the duct 17. The bottom surface 23 on which the screen-like collision plate 31 is provided may be the bottom surface of the horizontal duct 8, or may be the bottom surface on the vertical duct 9 side in the connection portion between the horizontal duct 8 and the vertical duct 9.

The plurality of screen-like collision plates 31 are fixed to the bottom surface 23 of the duct 17 and stand up, and are arranged in a line along the direction intersecting with the exhaust gas flow direction (front-rear direction) while being separated from each other. The screen-like collision plates 31 of the present embodiment are arranged in a straight line along a direction substantially orthogonal to the exhaust gas flow direction. The screen-like collision plate 31 is formed by welding a rod-like or tubular collision plate fixing member 32 to the bottom surface 23 (welding portion 33) and welding the screen-like collision plate 31 to the front side of the collision plate fixing member 32 (welding portion 34). To the bottom surface 23. The number of the screen-like collision plates 31 is not limited to three and is arbitrary.

In order to improve the collection rate of ash particles having a large particle size by the rear hopper 15 while suppressing an increase in the flow resistance of the exhaust gas, the screen-like collision plate 31 stands substantially perpendicular to the bottom surface 23, and the bottom surface 23 The protruding amount (projecting height) H1 of the screen-like collision plate 31 from 10 is set to 10 to 15% of the width in the height direction of the horizontal duct 8 (the vertical distance from the bottom surface 23 to the ceiling surface 22) H2. The front-side position L1 of the screen-like collision plate 31 is the rear side (the hopper upper end opening 19 side) of the bottom surface 23 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

In the screen-like collision plate 31A inclined forward and downward as shown by a two-dot chain line in FIG. 4, ash particles are likely to stay in the space 35 between the screen-like collision plate 31A and the bottom surface 23, thereby causing a flow resistance of the exhaust gas. In the screen-like collision plate 31B inclined rearward and upward as shown by a broken line in FIG. 4, the upper surface of the screen-like collision plate 31B guides the ash particles upward away from the rear hopper 15, so The standing direction is preferably substantially perpendicular to the bottom surface 23. Further, if the protruding height H1 of the screen-like collision plate 31 is excessively high (too high), the exhaust gas flow resistance increases, and if it is excessively low (too low), the effect of collecting large-sized ash particles is greatly improved. Therefore, the projection height H1 of the screen-like collision plate 31 is preferably in the above range.

Further, the screen-like collision plates 31 located at both ends of the plurality of screen-like collision plates 31 are arranged apart from the side surface 24 of the duct 17. This is because, when the screen-like collision plate 31 is in contact with the side surface 24, the ash particles stay between the screen-like collision plate 31 and the side surface 24, thereby providing a flow resistance of the exhaust gas.

2 and 5, a rectangular flat inclined collision plate 36 is fixed to the lower portion of the rear surface 26 of the duct 17 (lower portion of the rear surface of the vertical duct 9). The inclined collision plate 36 is formed by welding a rod-like or tubular collision plate fixing member 37 to the rear surface 26 (welding portion 38) and welding the inclined collision plate 36 to the rear surface 26 and the collision plate fixing member 37 (welding portion 39). Fixed to the rear face 26. The inclined collision plate 36 is disposed over the substantially entire area in the duct width direction behind the guide vane 28 and extends from the rear surface 26 to be inclined forward and downward.

In order to improve the collection rate of ash particles having a large particle size by the rear hopper 15 while suppressing an increase in the flow resistance of the exhaust gas, the protruding amount L3 of the inclined collision plate 36 from the rear surface 26 of the duct 17 is the vertical duct 9. Is set to 5 to 15% of L4 (distance between front surface 25 and rear surface 26) L4.

As shown by a two-dot chain line in FIG. 5, the inclined collision plate 36A that protrudes substantially horizontally accumulates ash particles on the upper surface, and it is necessary to reinforce the vibration of the inclined collision plate 36A caused by the upward flow. In the inclined collision plate 36B that is excessively inclined and has a small protrusion amount from the rear surface 26, the ash particles are difficult to contact the inclined collision plate 36B. It is preferable to incline toward.

In this embodiment, the screen-like collision plates 31 are arranged in one row. However, as shown in FIG. 6, the screen-like collision plates 31 may be arranged in a plurality of rows (two rows in the example of FIG. 6) in a staggered manner. Good.

Further, in the present embodiment, the flat inclined collision plates 36 are arranged in one stage. However, 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). Further, the protruding amount of the inclined collision plate 36 from the rear surface 26 may be different between the respective stages (for example, in the case of two stages, the upper stage and the lower stage). Moreover, as shown in FIG.7 (b), it is good also as the curved collision plate-shaped inclined collision board 40 from which an upper surface becomes convex.

Next, a case where the coal fired boiler 1 is operated using coal 2 having a high ash content and difficult to pulverize will be described.

In the operation of the coal fired boiler 1, the coal fired boiler 1 is supplied with coal 2 and combustion gas (air) 3 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 pipe 5, the economizer 6 and the like to generate steam, and the turbine generator generates power.

Since the coal 2 that burns in the coal fired boiler 1 has a high ash content and is difficult to pulverize, the exhaust gas contains a large amount of ash having a particle size (diameter) of 100 μm or more. The exhaust gas generated by 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. A part of the large ash particles unevenly distributed in the lower part of the horizontal duct 8 and entrained in the exhaust gas collide with the screen-like collision plate 31 rising from the bottom surface 23 of the duct 17 upstream of the rear hopper 15. The flow velocity decreases and falls to the rear hopper 15. In addition, some of the ash particles having a large particle size that do not fall from the bottom surface 23 of the duct 17 to 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. And then falls to the rear hopper 15. As described above, the ash particles having a large particle size in the exhaust gas are efficiently collected by the rear hopper 15 by the screen-type collision plate 31 and the inclined collision plate 36, and most of the ash particles are removed from the exhaust gas.

The exhaust gas from which most of the ash particles having a large particle size have been removed is supplied with ammonia from the ammonia supply nozzle 10c and then guided to the denitration catalyst 10b. NOx in the exhaust gas is reduced while passing through the denitration catalyst 10b. It is decomposed into nitrogen and water. As described above, since most of the ash particles having a large particle size in the exhaust gas are removed before passing through the denitration catalyst 10b, wear of the denitration catalyst 10b can be suppressed. The exhaust gas that has passed through the denitration catalyst 10b is subjected to heat exchange with the combustion air by the air heater 11 to become a low temperature, ash particles are removed by the dust collector 12, and sulfur oxides are removed by the desulfurizer 13, and then the chimney 14 is released into the atmosphere.

Next, the effect of collecting large-sized ash particles by the screen-like collision plate 31 and the inclined collision plate 36 will be described with reference to FIGS. 8 to 11, the front hopper 16 is expressed as the hopper 1, and the rear hopper 15 is expressed as the hopper 2.

8 to 11 show the collection ratio (collection rate%) of ash particles for each particle diameter (37 μm, 65 μm, 115 μm, 200 μm, 360 μm) by the front hopper (hopper 1) 16 and the rear hopper (hopper 2) 15. It is the result obtained by analysis. FIG. 8 (Comparative Example 1) shows that when both the screen-like 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 one row of screen-like collisions. When the plate 31 is provided, FIG. 10 (Embodiment 2) is not provided with the screen-like collision plate 31, but when the flat plate-shaped inclined collision plate 36 is provided, FIG. 11 (Embodiment 3) is one row. These results are obtained when the screen-like collision plate 31 and the flat plate-shaped inclined collision plate 36 are provided. FIG. 12 shows the flow of exhaust gas from the exhaust gas outlet 7 to the denitration catalyst 10b in Example 3 (provided with one row of partitioning collision plates 31 and a flat plate-shaped inclined collision plate 36). FIG. 13 shows the 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 Example 3.

From FIG. 8 to FIG. 11, the collection rate of the large ash particles by the rear hopper 15 is improved by providing the screen-like collision plate 31 and the inclined collision plate 36, and only the screen-like collision plate 31 or the inclined collision. It can be seen that the collection rate is improved even when only the plate 36 is provided. 12 and 13 that the ash particles having a large particle size can be well collected by the rear hopper 15 while suppressing the disturbance of the flow of exhaust gas (increase in the flow resistance).

As described above, according to this 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 exhaust gas.

In the embodiment shown in FIG. 1, the case where both the partition-like collision plate 31 and the inclined collision plate 36 are provided has been described, but only one of them may be provided.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, an inclined collision surface 41 is added to the first embodiment, and other configurations are the same as those in the first embodiment, and therefore, the description overlapping with the first embodiment is omitted.

As shown in FIG. 14, the guide vane 28 is disposed at the lower end portion (the end portion on the horizontal duct 8 side) of the guide vane 28 over substantially the entire area in the duct width direction and covers the front and lower sides of the guide fixing member 29. The protector 42 is fixed. The guide vane protector 42 is a plate member having an L-shaped cross section, and is inclined in a rearward and downward direction from a flat plate-shaped protector front plate portion 43 that is inclined forward and downward in front of the guide fixing member 29 and a lower end edge of the protector front plate portion 43. And a flat plate-like protector lower plate portion 44 extending integrally. The protector lower plate portion 44 is fixed to the guide vane 28 via the support 45.

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 is provided with 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 46 constitutes an inclined collision surface 41 that is fixedly provided at the lower end portion of the lowermost guide vane 28A and is inclined rearward and downward.

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 arc shaped protector front plate portion 47 curved along the front outer surface of the guide fixing member 29 and Further, it may be a J-shaped cross section integrally including a flat plate-like protector lower plate portion 44 extending obliquely downward and rearward from the lower end edge of the protector front plate portion 47.

According to this embodiment, with 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 collided with the inclined collision surface 41 and collected by the rear hopper 15, and the collection rate of the large ash particles is further improved.

In addition, this invention is not limited to the above-mentioned embodiment and modification which were demonstrated as an example, If it is the range which does not deviate from the technical idea which concerns on this invention also except the above-mentioned embodiment etc. Various changes can be made according to the design and the like.

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 space 19: Hopper upper end opening 20: Front end edge of hopper upper end opening 21: Rear end edge of hopper upper end opening 23: Duct bottom face 26: Duct rear face 28: Guide vane 28A: Bottom guide vane 31: screen-like collision plate 36, 40: inclined collision plate 41: inclined collision surface

Claims

An exhaust gas treatment device for reducing nitrogen oxides in exhaust gas discharged from a coal fired boiler by a denitration device,
A horizontal duct extending in a substantially horizontal direction and a vertical duct extending in a substantially vertical direction, wherein a front end of the horizontal duct communicates with an exhaust gas outlet of the coal fired boiler, and a rear end of the horizontal duct is at a lower end of the vertical duct A duct that divides a space in the duct that communicates the exhaust gas discharged from the coal fired boiler from above the horizontal duct to above the vertical duct to guide the denitration device;
A hopper provided below the vertical duct and communicating with the space in the duct through a hopper upper end opening;
Continuously extending from the front edge of the upper end opening of the hopper and standing uprightly fixed to the bottom surface of the duct that defines the lower part of the duct interior space, along the direction intersecting with the flow direction of the exhaust gas while being separated from each other An exhaust gas treatment apparatus comprising: a plurality of screen-like collision plates arranged in a line.
An exhaust gas treatment device for reducing nitrogen oxides in exhaust gas discharged from a coal fired boiler by a denitration device,
A horizontal duct extending in a substantially horizontal direction and a vertical duct extending in a substantially vertical direction, wherein a front end of the horizontal duct communicates with an exhaust gas outlet of the coal fired boiler, and a rear end of the horizontal duct is at a lower end of the vertical duct A duct that divides a space in the duct that communicates the exhaust gas discharged from the coal fired boiler from above the horizontal duct to above the vertical duct to guide the denitration device;
A hopper provided below the vertical duct and communicating with the space in the duct through a hopper upper end opening;
An inclined collision plate that extends continuously upward from a rear end edge of the hopper upper end opening and is fixed to a rear surface of the duct that divides the rear of the duct internal space, and extends obliquely forward and downward from the rear surface. An exhaust gas treatment apparatus characterized by that.
The exhaust gas treatment apparatus according to claim 1 or 2,
A plurality of guide vanes disposed in the duct space above the hopper, fixed to the duct and vertically overlapped with each other, and guiding the exhaust gas flowing from the horizontal duct to the vertical duct vertically upward;
An exhaust gas treatment apparatus, comprising: an inclined collision surface fixedly provided at an end of the lowermost guide vane on the horizontal duct side of the plurality of guide vanes and extending obliquely rearward and downward. .