WO2013114722A1

WO2013114722A1 - Exhaust gas treatment device

Info

Publication number: WO2013114722A1
Application number: PCT/JP2012/081344
Authority: WO
Inventors: 章泰岡元; 心平戸▲高▼; 学小田; 坂田　展康; 博美河越
Original assignee: 三菱重工業株式会社
Priority date: 2012-01-30
Filing date: 2012-12-04
Publication date: 2013-08-08
Also published as: CN104024735B; TW201350761A; JP5854863B2; CN104024735A; TWI589816B; IN2014CN04950A; JP2013155939A

Abstract

The exhaust gas treatment device is provided with: an exhaust gas pipe (48) through which it is possible for combustion gases to flow; a heat recovery part furnished to the exhaust gas pipe (48) and capable of recovering heat from the exhaust gases; a harmful substance removal part furnished to the downstream side in the direction of exhaust gas flow from the heat recovery part in the exhaust gas pipe (48), and capable of removing harmful substances in the exhaust gases; and a popcorn ash trapping part (61) furnished between the heat recovery part and the harmful substance removal part in the exhaust gas pipe (48), and capable of trapping popcorn ash in the exhaust gases. In the popcorn ash trapping part (61), a plurality of protruding parts (66) which protrude towards the upstream side in the direction of exhaust gas flow are lined up along two intersecting directions.

Description

Exhaust gas treatment system

TECHNICAL FIELD The present invention relates to an exhaust gas processing device applied to a boiler for generating steam for power generation or factory use.

For example, a conventional pulverized coal burning boiler has a hollow furnace and has a vertically installed furnace, and a plurality of combustion burners are disposed along the circumferential direction on the furnace wall, and a plurality of stages in the vertical direction are provided. Are placed across. The combustion burner is supplied with a mixture of pulverized coal (fuel) and primary air from which coal has been crushed, and is supplied with high temperature secondary air, and this mixture and secondary air are blown into the furnace. Form a flame, which can be burned in this furnace. A flue is connected to the upper part of the furnace, and a superheater, a reheater, a economizer, etc. for recovering the heat of the exhaust gas are provided in the flue, and it was generated by the combustion in the furnace Heat exchange takes place between the exhaust gas and the water and steam can be generated. Further, in the flue, an exhaust gas passage is connected, a denitration device, an electrostatic precipitator, a desulfurization device and the like are provided in the exhaust gas passage, and a chimney is provided at a downstream end.

In such a pulverized coal-fired boiler, since the pulverized coal as a fuel is burned in a furnace, popcorn ash is mixed in the exhaust gas. Since this popcorn ash is a lump of ash, it adheres particularly to a denitration device provided in the exhaust gas passage, and the pressure loss is increased to cause performance degradation. Therefore, conventionally, a wire mesh or the like is provided in the exhaust gas passage to remove popcorn ash from the exhaust gas. As such a technique, there exist some which were described in the following patent documents 1 and 2, for example.

Patent No. 2724176 gazette U.S. Patent No. 6,994,036

As described above, the exhaust gas generated in the boiler furnace is mixed with popcorn ash, which is a lump of ash of several millimeters to several tens of millimeters. On the other hand, the wire mesh provided in the exhaust gas passage is a mesh of several millimeters or less. Therefore, when a large amount of popcorn ash collides with a wire mesh or the like, there is a problem that the mesh of the wire mesh is locally clogged, wear occurs, or the wire mesh is broken.

The present invention solves the above-mentioned problem, and an object of the present invention is to provide an exhaust gas processing system capable of properly collecting popcorn ash.

In order to achieve the above object, an exhaust gas processing apparatus according to the present invention includes an exhaust gas passage capable of flowing a combustion gas, a heat recovery unit provided in the exhaust gas passage and capable of recovering heat in the exhaust gas, and A harmful substance removing unit provided downstream of the heat recovery unit in the flow direction of the exhaust gas and capable of removing harmful substances in the exhaust gas, and provided between the heat recovery unit and the harmful substance removing unit in the exhaust gas passage And a popcorn ash collecting portion capable of collecting popcorn ash in exhaust gas, wherein the popcorn ash collecting portion is a two-way direction in which a plurality of projections projecting forward or backward in the flow direction of the exhaust gas intersect Are arranged side by side along the line.

Therefore, the exhaust gas flowing through the exhaust gas passage is subjected to heat recovery by the heat recovery unit, then popcorn ash is collected by the popcorn ash collection unit, and then harmful substances are removed by the harmful substance removal unit. At this time, since the popcorn ash collecting portion has a plurality of projecting portions, the popcorn ash collecting area becomes large and the pressure loss is reduced, and the popcorn ash can be collected efficiently. The damage to the popcorn ash collecting portion due to the popcorn ash is suppressed, and the popcorn ash can be collected properly.

In the exhaust gas treatment apparatus of the present invention, the connection parts to which the proximal ends of the plurality of projecting parts are connected are continuously arranged at substantially the same position in the flow direction of the exhaust gas and are inclined at a predetermined angle with respect to the horizontal direction It is characterized by

Therefore, since the connection portion of each protrusion is continuously inclined, the popcorn ash collected by the popcorn ash collecting portion is collected at this connection portion and easily falls, and stable capture of popcorn ash is achieved. Collection can be made possible.

In the exhaust gas processing system of the present invention, the connection portion is characterized by having a linear shape.

Therefore, by making the connection part in a linear shape, popcorn ash collected in the connection part can be easily dropped.

In the exhaust gas processing device of the present invention, the projection is characterized in that it has a polygonal pyramid shape.

Therefore, by forming the protrusion in a polygonal pyramid shape, a large number of inclined surfaces will be formed, the collection area of popcorn ash becomes large, the pressure loss can be easily reduced, and the popcorn ash can be made efficient. Can be collected.

In the exhaust gas processing apparatus of the present invention, the inclination angle with respect to the flow direction of the exhaust gas in the projecting portion disposed in the central portion of the exhaust gas passage inclines with respect to the flow direction in the exhaust gas disposed in the outer peripheral portion of the exhaust gas passage. It is characterized in that it is set smaller than the angle.

Therefore, since the inclination angle of the protrusion at the center of the exhaust gas passage is smaller than the inclination angle of the protrusion at the outer periphery, the relatively fast flow velocity popcorn ash flowing through the center of the exhaust gas passage is deflected. Since the flow velocity and pressure loss are reduced, damage to the popcorn ash collecting portion due to popcorn ash is suppressed, and popcorn ash can be properly collected.

In the exhaust gas processing apparatus of the present invention, the exhaust gas passage has a first passage and a second passage connected in a direction substantially orthogonal to each other and connected along the flow direction of the exhaust gas, the first passage and the second passage. A hopper capable of storing popcorn ash is provided below the communicating portion with the second passage, and the heat recovery portion is provided upstream of the first passage or the first pipe, and the second passage or the second passage is provided. The harmful substance removing unit is provided downstream of the pipe, and the popcorn ash collecting unit is provided in the second passage.

Therefore, by arranging the popcorn ash collecting portion at an appropriate position, it is possible to suppress damage to the popcorn ash collecting portion due to popcorn ash, and it is possible to properly collect popcorn ash.

According to the exhaust gas treating apparatus of the present invention, a popcorn ash collecting portion capable of collecting popcorn ash in the exhaust gas is provided between the heat recovery portion and the harmful substance removing portion in the exhaust gas passage capable of flowing combustion gas. Since the popcorn ash collecting portion is disposed along two directions crossing a plurality of projecting portions that project forward or backward in the flow direction of the exhaust gas, damage to the popcorn ash collecting portion due to popcorn ash is suppressed. And popcorn ash can be collected properly.

FIG. 1 is a schematic configuration diagram showing a pulverized coal burning boiler to which an exhaust gas processing device according to a first embodiment of the present invention is applied. FIG. 2 is a schematic side view showing the exhaust gas processing system of the first embodiment. FIG. 3 is a front view of the popcorn ash collecting unit in the exhaust gas processing system of the first embodiment. FIG. 4 is a plan view of the popcorn ash collecting unit of the first embodiment. FIG. 5 is a side view of the popcorn ash collecting unit of the first embodiment. FIG. 6 is a plan view of a popcorn ash collecting portion in an exhaust gas processing system according to a second embodiment of the present invention. FIG. 7 is a side view of the popcorn ash collecting unit of the second embodiment. FIG. 8 is a front view of a popcorn ash collecting unit in an exhaust gas processing system according to a third embodiment of the present invention. FIG. 9 is a plan view of the popcorn ash collecting unit of the third embodiment. FIG. 10 is a side view of the popcorn ash collecting unit of the third embodiment. FIG. 11 is a schematic side view showing an exhaust gas processing system according to a fourth embodiment of the present invention.

Hereinafter, preferred embodiments of the exhaust gas processing apparatus of the present invention will be described in detail with reference to the attached drawings. The present invention is not limited to the embodiments, and in the case where there are a plurality of embodiments, the present invention also includes those configured by combining the respective embodiments.

FIG. 1 is a schematic configuration view showing a pulverized coal burning boiler to which an exhaust gas treatment apparatus according to a first embodiment of the present invention is applied, FIG. 2 is a schematic side view showing an exhaust gas treatment apparatus according to the first embodiment, and FIG. 4 is a plan view of the popcorn ash collecting portion of the first embodiment, and FIG. 5 is a side view of the popcorn ash collecting portion of the first embodiment. It is.

The pulverized coal burning boiler to which the exhaust gas processing apparatus of Example 1 is applied uses the pulverized coal obtained by pulverizing coal as a solid fuel, burns the pulverized coal by a combustion burner, and recovers the heat generated by the combustion. It is a possible boiler.

In the first embodiment, as shown in FIG. 1, the pulverized coal burning boiler 10 is a conventional boiler, and has a furnace 11 and a combustion apparatus 12. The furnace 11 has a hollow shape of a square cylinder and is installed along the vertical direction, and the combustion apparatus 12 is provided at the lower part of the furnace wall constituting the furnace 11.

The combustion apparatus 12 has a plurality of

combustion burners

21, 22, 23, 24, 25 mounted on the furnace wall. In the present embodiment, four

combustion burners

21, 22, 23, 24, 25 are disposed at equal intervals along the circumferential direction, and five sets along the vertical direction, that is, as one set. Five stages are arranged.

And each

combustion burner

21,22,23,24,25 is connected with pulverized coal machine (mill) 31,32,33,34,35 via pulverized

coal supply pipe

26,27,28,29,30 ing. The pulverized

coal machine

31, 32, 33, 34, 35 is not shown, but the pulverizing table is rotatably supported within the housing with a rotational axis along the vertical direction, and is opposed to the upper side of the pulverizing table A plurality of grinding rollers are rotatably supported in association with the rotation of the grinding table. Therefore, when coal is introduced between a plurality of grinding rollers and a grinding table, the pulverized coal which has been pulverized to a predetermined size and classified by the carrier air (primary air) is divided into pulverized

coal supply pipes

26, 27. , 28, 29, 30 to the

combustion burners

21, 22, 23, 24, 25 can be supplied.

In the furnace 11, a wind box 36 is provided at the mounting position of each of the

combustion burners

21, 22, 23, 24, 25 and one end of an air duct 37 is connected to the wind box 36. In the duct 37, a blower 38 is mounted at the other end. Therefore, the combustion air (secondary air, tertiary air) sent by the blower 38 is supplied from the air duct 37 to the air box 36, and the air box 36 supplies the

combustion burners

21, 22, 23, 24, 25. Can be supplied.

Therefore, in the combustion apparatus 12, the

combustion burners

21, 22, 23, 24, 25 can blow a pulverized fuel mixture (fuel gas) obtained by mixing pulverized coal and primary air into the furnace 11. The secondary air can be blown into the furnace 11, and a flame can be formed by igniting the pulverized fuel mixture with an ignition torch (not shown).

Generally, at the start of the boiler, each of the

combustion burners

21, 22, 23, 24, 25 injects oil fuel into the furnace 11 to form a flame.

The flue 40 is connected to the upper part of the furnace 11 and superheaters (superheaters) 41 and 42 for recovering the heat of the exhaust gas as a convection heat transfer part (heat recovery part) are connected to the flue 40.

Heaters

43 and 44 and

economizers

45, 46 and 47 are provided, and heat exchange is performed between the exhaust gas generated by the combustion in the furnace 11 and water.

The flue 40 is connected downstream with an exhaust gas pipe (exhaust gas passage) 48 through which the exhaust gas subjected to heat exchange is discharged. The exhaust gas pipe 48 is provided with an air heater 49 between it and the air duct 37, and performs heat exchange between the air flowing through the air duct 37 and the exhaust gas flowing through the exhaust gas pipe 48, and the

combustion burners

21, 22, 23, The temperature of the combustion air supplied to 24, 25 can be raised.

In the exhaust gas pipe 48, the selective reduction catalyst 50 is provided at a position upstream of the air heater 49, and the electrostatic precipitator 51, the induction fan 52, and the desulfurization device 53 are provided at a position downstream of the air heater 49. A chimney 54 is provided in the Here, the selective reduction catalyst 50, the electrostatic precipitator 51, and the desulfurizer 53 function as a harmful substance removing unit.

Therefore, when the pulverized

coal machine

31, 32, 33, 34, 35 is driven, the pulverized coal produced together with the transfer air passes through the pulverized

coal supply pipe

26, 27, 28, 29, 30 and the

combustion burners

21, 22, 23, 23, 24 and 25 are supplied. Further, the heated combustion air is supplied from the air duct 37 to the

combustion burners

21, 22, 23, 24, 25 via the air box 36. Then, the

combustion burners

21, 22, 23, 24, 25 blow the pulverized fuel mixture of the pulverized coal and the conveying air into the furnace 11 and also the combustion air into the furnace 11 and ignite at this time. Can form a flame. In the furnace 11, the pulverized fuel mixture and the combustion air are burned to generate a flame, and when a flame is generated in the lower part in the furnace 11, the combustion gas (exhaust gas) ascends in the furnace 11 and the flue It is discharged to 40.

In the furnace 11, the inside is maintained in a reducing atmosphere by setting the amount of supplied air to be less than the theoretical amount of air with respect to the supplied amount of pulverized coal. Then, the NOx generated by the combustion of the pulverized coal is reduced by the furnace 11, and after that, additional air is additionally supplied to complete the oxidation combustion of the pulverized coal, and the amount of NOx generated by the combustion of the pulverized coal is reduced. .

At this time, water supplied from a water supply pump (not shown) is preheated by

economizers

45, 46 and 47 and then supplied to a steam drum (not shown) and supplied to water pipes (not shown) of the furnace wall. It is heated to become saturated steam and is fed to a steam drum (not shown). Furthermore, saturated steam of a steam drum (not shown) is introduced into the

superheaters

41 and 42 and is overheated by the combustion gas. The superheated steam generated by the superheaters 41 and 42 is supplied to a power plant (for example, a turbine etc.) not shown. Further, the steam taken out in the middle of the expansion process in the turbine is introduced into the

reheaters

43 and 44, and is again overheated and returned to the turbine. In addition, although the furnace 11 was demonstrated as a drum type (steam drum), it is not limited to this structure.

Thereafter, the exhaust gas passing through the

economizers

45, 46, 47 of the flue 40 is subjected to the selective reduction catalyst 50 to remove harmful substances such as NOx by the exhaust gas pipe 48, and the particulate matter is removed by the electrostatic precipitator 51 After the sulfur content is removed by the desulfurization device 53, the sulfur is discharged from the chimney 54 to the atmosphere.

In the pulverized coal burning boiler 10 configured as described above, the downstream side of the furnace 11 functions as the exhaust gas processing device of the first embodiment. And, in the exhaust gas processing system of this embodiment 1, the heat recovery part (

superheaters

41, 42,

reheaters

43, 44,

economizer

45, 46, 47) and harmful substance removing part (selective reduction) in the exhaust gas pipe 48 The popcorn ash collecting portion 61 capable of collecting popcorn ash in the exhaust gas is provided between the catalyst 50, the electrostatic precipitator 51, and the desulfurizing device 53), and the popcorn ash collecting portion 61 A plurality of forwardly projecting protrusions 66 are arranged side by side along two intersecting directions.

That is, as shown in FIG. 2, the exhaust gas pipe 48 has, for example, a rectangular cross section, and a first pipe (first passage) 48a extending along the vertical direction and a second pipe extending along the horizontal direction The first pipe 48a and the second pipe 48b communicate with each other in a direction substantially orthogonal to each other. In this case, a heat recovery unit is provided on the first pipe 48a side located upstream of the flowing direction of the exhaust gas, and a harmful substance removing unit is provided on the second pipe 48b side located downstream of the flowing direction of the exhaust gas, The passage area of the second pipe 48b is set smaller than the passage area of the first pipe 48a. And the popcorn ash collection part 61 is provided in the 2nd piping 48b.

Further, the first pipe 48a and the second pipe 48b communicate with the rear end portion and the front end portion, and a hopper 62 capable of storing popcorn ash is provided below the communication portion. The hopper 62 is formed by opposing inclined surfaces so as to narrow the area downward, and the lower end portion is at a position lower than the bottom surface of the second pipe 48b. The hopper 62 not only stores popcorn ash collected and dropped by the popcorn ash collecting portion 61, but also popcorn ash in the exhaust gas flowing directly from the first pipe 48a to the second pipe 48b is directly hopperd 62. The popcorn ash can be discharged downward by opening the opening with an open / close valve (not shown). And the popcorn ash collection part 61 is inclined and provided in the inlet part of 2nd piping 48b so that it may be located in the downstream of the flow direction of waste gas from the hopper 62. As shown in FIG.

The popcorn ash collecting portion 61 is fixed to

brackets

63 and 64 whose upper and lower end portions are fixed to the upper and lower wall surfaces of the inlet portion of the second pipe 48b. And this popcorn ash collection part 61 is inclined and arrange | positioned by a predetermined angle so that a lower end part may be located in the downstream of the flow direction of waste gas. The popcorn ash collecting portion 61 is formed of, for example, a mesh-shaped wire mesh, and includes a large number of openings of 2 mm to 3 mm or less. The popcorn ash collecting portion 61 is not limited to the mesh-like wire mesh, and may be a screen having a longitudinal slit or a lateral slit, a porous body, or the like.

Further, a kicker (guide portion) 65 for guiding the exhaust gas to the outside of the corner is provided at the inside of the corner at the communication portion between the first pipe 48a and the second pipe 48b. The kicker 65 projects from the inner wall surface of the lower end portion of the first pipe 48 a to the opposing inner wall surface outside the bend angle inside the bend in the communication portion between the first pipe 48 a and the second pipe 48 b. , And has a tapered cross section.

Here, first, the popcorn ash collecting unit 61 will be described in detail. As shown in FIGS. 3 to 5, in the popcorn ash collecting portion 61, a plurality of projecting portions 66 project forward in the flowing direction of the exhaust gas, and the plurality of projecting portions 66 intersect in two directions crossing each other, that is, , Are arranged side by side along the horizontal direction and the vertical direction (or two inclined directions).

The plurality of protrusions 66 all have the same shape. That is, since one protrusion (shown by oblique lines in FIGS. 3 to 5) 66 has a quadrangular pyramid shape, it has four

inclined collection surfaces

67a, 67b, 67c, and 67d. , The center is the apex of the square pyramid. In the present embodiment, since the protrusion 66 having a quadrangular pyramid shape has a rhombus shape that is long in the vertical direction in a front view (FIG. 3), the four

inclined collection surfaces

67a, 67b, 67c, and 67d are Although the shapes are symmetrical, they have different shapes.

Further, since the plurality of projecting portions 66 project to the upstream side in the flow direction of the exhaust gas, connection portions 68 to which base end portions located on the downstream side in the flow direction of the exhaust gas are connected are formed. The connecting portion 68 is disposed continuously at substantially the same position in the flow direction of the exhaust gas, and is disposed in a linear shape so as to be inclined at a predetermined angle with respect to the horizontal direction. In this case, the connecting portion 68 is located along the inclination direction of the popcorn ash collecting portion 61 itself.

Next, the operation of the exhaust gas processing system of the first embodiment will be described. As shown in FIGS. 1 to 5, the exhaust gas flowing through the exhaust gas pipe 48 has its heat recovered by the heat recovery unit (superheaters 41 and 42, reheaters 43 and 44,

economizers

45, 46 and 47) After that, it flows downward along the first pipe 48a. Then, the exhaust gas bends the communication part substantially at right angles and flows to the popcorn ash collecting part 61.

Here, the exhaust gas is guided to the center side of the communicating portion by the kicker 65 inside the bend in the communicating portion between the first pipe 48a and the second pipe 48b, so that the flow is separated and the flow velocity is lowered. Do. And popcorn ash is collected by the popcorn ash collection part 61 in the exhaust gas. Further, in the exhaust gas flowing outside the bend in the communication portion between the first pipe 48a and the second pipe 48b, part of the popcorn ash comes in contact with the inclined surface of the hopper 62 and falls.

At this time, since the popcorn ash collecting portion 61 is configured by arranging a plurality of protruding portions 66 formed of four

inclined collecting surfaces

67a, 67b, 67c, and 67d in parallel, the collecting area of the popcorn ash ( The open area is increased, the pressure loss is reduced, and popcorn ash is efficiently collected. As a result, the impact force of popcorn ash on the popcorn ash collecting portion 61 is alleviated, and wear and damage of the popcorn ash collecting portion 61 are suppressed.

Then, although a predetermined amount of popcorn ash collected by the popcorn ash collecting portion 61 is attached, the popcorn ash collecting portion 61 is inclined, and the connecting portions 68 of the respective protruding portions 66 are in the vertical direction. Since it is inclined to the opposite side, it is freely dropped and stored in the hopper 62.

After that, the exhaust gas from which the popcorn ash has been removed by the popcorn ash collecting unit 61 has the harmful substances removed by the harmful substance removing unit (selective reduction type catalyst 50, electric dust collector 51, desulfurizer 53).

As described above, in the exhaust gas processing apparatus of the first embodiment, the exhaust gas pipe 48 capable of flowing the combustion gas, the heat recovery unit provided in the exhaust gas pipe 48 capable of recovering the heat in the exhaust gas, and the exhaust gas pipe 48 A harmful substance removing unit provided downstream of the heat recovery unit in the flow direction of the exhaust gas and capable of removing harmful substances in the exhaust gas, and provided between the heat recovery unit and the harmful substance removing unit in the exhaust gas pipe 48 And a popcorn ash collecting portion 61 capable of collecting the popcorn ash in the middle, and as the popcorn ash collecting portion 61, along two directions crossing a plurality of projecting portions 66 projecting to the upstream side in the flow direction of the exhaust gas. It is juxtaposed.

Therefore, the exhaust gas flowing through the exhaust gas pipe 48 is subjected to heat recovery by the heat recovery unit, then popcorn ash is collected by the popcorn ash collection unit 61, and then harmful substances are removed by the harmful substance removal unit. At this time, since the popcorn ash collecting portion 61 has a plurality of projecting portions 66, the collecting area of the popcorn ash is increased, the pressure loss is reduced, and the popcorn ash can be collected efficiently. it can. As a result, damage to the popcorn ash collecting portion 61 due to popcorn ash is suppressed, and popcorn ash can be collected properly. Further, since the amount of protrusion in the upper, lower, left, and right portions of the protrusion 66 can be adjusted, it is possible to perform angle adjustment corresponding to a portion where the flow velocity is high and which is easily worn away.

Further, in the exhaust gas processing apparatus of the first embodiment, the connection portions 68 to which the base end portions of the plurality of projecting portions 66 are connected are continuously arranged at substantially the same position in the flow direction of the exhaust gas, and predetermined in the horizontal direction. It is inclined at an angle. Therefore, since the connecting portion 68 of each projecting portion 66 is continuously inclined, the popcorn ash collected by the popcorn ash collecting portion 61 is accumulated in the connecting portion 68 and is easily dropped, so that the popcorn ash is obtained. Stable collection of

Further, in the exhaust gas processing system of the first embodiment of the present invention, the connecting portion 68 has a linear shape. Therefore, popcorn ash accumulated in the connection portion 68 can be easily dropped, and since the popcorn ash linearly falls on the connection portion 68, the deposition amount can be reduced.

Further, in the exhaust gas processing system of the first embodiment, the projecting portion 66 is formed in a polygonal pyramid (square pyramid) shape. Therefore, a large number of

inclined surfaces

67a, 67b, 67c, 67d are formed by the projecting portion 66, the area of collection of popcorn ash is increased with a simple configuration, and pressure loss can be easily reduced, resulting in popcorn Ash can be collected efficiently.

6 is a plan view of a popcorn ash collecting portion in an exhaust gas processing device according to a second embodiment of the present invention, and FIG. 7 is a side view of the popcorn ash collecting portion of the second embodiment.

In the second embodiment, the basic configuration of the exhaust gas processing system is the same as that of the first embodiment, and only the configuration of the popcorn ash collecting portion is different. As shown in FIGS. 6 and 7, in the popcorn ash collecting portion 71, the plurality of

protrusions

72a and 72b protrude forward in the flow direction of the exhaust gas, and the plurality of

protrusions

72a and 72b intersect each other 2 It is juxtaposed along the direction. The plurality of protrusions 72a disposed in the central portion of the exhaust gas pipe all have the same shape. Further, the plurality of protrusions 72b in the flow direction of the exhaust gas all have the same shape. And since one

projection part

72a, 72b makes square pyramid shape, it has four inclination collection surfaces. In the present embodiment, since the

projections

72a and 72b having a quadrangular pyramid shape are in the shape of a diamond which is long in the vertical direction in front view, the four inclined collection surfaces have symmetry. It has a different shape.

Further, the popcorn ash collecting portion 71 has an inclination angle with respect to the flowing direction of the exhaust gas in the projecting portion 72a disposed in the central portion of the exhaust gas pipe, and an inclination angle with respect to the flowing direction of the exhaust gas in the projecting portion 72b disposed in the outer peripheral portion of the exhaust gas pipe It is set smaller than the angle.

And since

several protrusion part

72a, 72b protrudes in the upstream in the flow direction of waste gas, the connection part 73 to which the proximal end part located in the downstream of the flow direction of waste gas is connected is formed, respectively There is. The connection portion 73 is disposed continuously at substantially the same position in the flow direction of the exhaust gas, and is disposed in a linear shape so as to be inclined at a predetermined angle with respect to the horizontal direction.

Accordingly, the exhaust gas flowing through the exhaust gas pipe flows to the popcorn ash collecting unit 71 after heat is recovered by the heat recovery unit, and the popcorn ash collecting unit 71 collects the popcorn ash here. At this time, since the popcorn ash collecting portion 71 is configured by arranging a plurality of protruding

portions

72a and 72b formed of four inclined collecting surfaces side by side, the collecting area (opening area) of the popcorn ash is large. Popcorn ash is collected efficiently. Further, in the popcorn ash collecting portion 71, since the inclination angle of the projecting portion 72a at the central portion is set smaller than the inclination angle of the projecting portion 72b at the outer peripheral portion, the central portion of the exhaust gas pipe opens from the outer peripheral portion. The area is getting larger. Therefore, although the exhaust gas flowing through the exhaust gas pipe has a relatively high flow velocity at the central portion side, the opening area becomes large at the central portion side, so the exhaust gas (popcorn ash) has its flow deflected by the projecting portion 72a. Flow rate and pressure loss are reduced. As a result, the impact force of the popcorn ash on the popcorn ash collecting portion 71 is alleviated, and the wear and damage of the popcorn ash collecting portion 71 are suppressed.

Then, although a predetermined amount of popcorn ash collected by the popcorn ash collecting portion 71 is attached, since the connecting portions 73 of the projecting

portions

72a and 72b of the popcorn ash collecting portion 71 are inclined, Fall free. After that, the exhaust gas from which the popcorn ash has been removed by the popcorn ash collecting unit 71 has the harmful substance removing unit removing the harmful substances.

As described above, in the exhaust gas processing apparatus of the second embodiment, the popcorn ash collecting portion 71 is provided in parallel along two directions crossing the plurality of projecting

portions

72a and 72b protruding upstream in the flowing direction of the exhaust gas. The inclination angle with respect to the flowing direction of the exhaust gas in the projecting portion 72a disposed in the central portion of the exhaust gas pipe is set smaller than the inclination angle with respect to the flowing direction of the exhaust gas in the projecting portion 72b disposed in the outer peripheral portion of the exhaust gas pipe.

Accordingly, the exhaust gas flowing through the exhaust gas pipe 48 is subjected to heat recovery by the heat recovery unit, then popcorn ash is collected by the popcorn ash collection unit 71, and then harmful substances are removed by the harmful substance removal unit. At this time, since the popcorn ash collecting portion 71 has the plurality of projecting

portions

72a and 72b, the collection area of the popcorn ash is increased, and the popcorn ash can be collected efficiently. In addition, since the inclination angle of the protrusion 72a at the central portion of the exhaust gas pipe is set smaller than the inclination angle of the protrusion 72b at the outer peripheral portion, popcorn ash having a relatively high flow velocity flowing through the central portion of the exhaust gas pipe Since the flow is deflected to reach the projecting portion 72a, the flow velocity and pressure loss are reduced, damage to the popcorn ash collecting portion 71 due to popcorn ash is suppressed, and popcorn ash is properly collected. Can.

That is, in the popcorn ash collecting portion 71, the inclination angle of the inclined collecting surface of the projecting portion 72a is small at the central portion side where the flow velocity of exhaust gas is high, and the inclined collecting surface at the projecting portion 72b is peripheral The inclination angle of is set large. Therefore, without unnecessarily expanding the collection area of the popcorn ash collection unit 71, only the necessary parts are enlarged, and popcorn in the exhaust gas can be efficiently collected while suppressing the manufacturing cost. it can.

8 is a front view of a popcorn ash collecting unit in an exhaust gas processing apparatus according to a third embodiment of the present invention, FIG. 9 is a plan view of the popcorn ash collecting unit of the third embodiment, and FIG. It is a side view of a popcorn ash collection part.

In the third embodiment, the basic configuration of the exhaust gas processing system is the same as that of the first embodiment, and only the configuration of the popcorn ash collecting portion is different. As shown in FIGS. 8 to 10, in the popcorn ash collecting portion 81, a plurality of

projections

82, 83 project forward in the flow direction of the exhaust gas, and the plurality of

projections

82, 83 intersect each other 2 It is juxtaposed along the direction.

The plurality of

protrusions

82 and 83 have the same shape, but the

protrusions

82 and 83 have a shape that is line symmetrical. That is, since the projecting portions (represented by oblique lines in FIGS. 8 to 10) 82 and 83 respectively have a triangular pyramid shape as a polygonal pyramid shape, three

inclined collection surfaces

84a, 84b, 84c, 3 There are two

inclined collecting surfaces

85a, 85b, 85c, the centers of which are the apexes of the triangular pyramids.

Further, since the plurality of projecting

portions

82, 83 project upstream in the flow direction of the exhaust gas, connection portions 86 to which the base end portions located on the downstream side in the flow direction of the exhaust gas are connected are formed. There is. The connecting portion 86 is disposed continuously at substantially the same position in the flow direction of the exhaust gas, and is disposed in a linear shape so as to be inclined at a predetermined angle with respect to the horizontal direction. In this case, the connecting portion 86 is composed of one extending in the vertical direction between the projecting

portions

82 and 83 and one extending at an angle of 45 degrees with respect to the vertical direction.

Accordingly, the exhaust gas flowing through the exhaust gas pipe flows to the popcorn ash collecting unit 81 after heat is recovered by the heat recovery unit, and the popcorn ash collecting unit 81 collects the popcorn ash here. At this time, since the popcorn ash collecting portion 81 is configured by arranging a plurality of protruding

portions

82 and 83 formed of six

inclined collecting surfaces

84a, 84b, 84c, 85a, 85b and 85c in parallel, popcorn The collection area (opening area) of the ash is increased, the pressure loss is reduced, and popcorn ash is efficiently collected. As a result, the impact force of the popcorn ash on the popcorn ash collecting portion 71 is alleviated, and the wear and damage of the popcorn ash collecting portion 71 are suppressed.

Then, although a predetermined amount of popcorn ash collected by the popcorn ash collecting portion 81 adheres, since the connecting portions 86 of the projecting

portions

82 and 83 of the popcorn ash collecting portion 81 are inclined, Fall free. After that, the exhaust gas from which the popcorn ash has been removed by the popcorn ash collecting unit 71 has the harmful substance removing unit removing the harmful substances.

As described above, in the exhaust gas processing apparatus of the third embodiment, the popcorn ash collecting portion 81 is provided in parallel along two directions crossing the plurality of projecting

portions

82 and 83 protruding upstream in the flowing direction of the exhaust gas. doing.

Therefore, the exhaust gas flowing through the exhaust gas pipe is subjected to heat recovery by the heat recovery unit, then popcorn ash is collected by the popcorn ash collection unit 81, and then harmful substances are removed by the harmful substance removal unit. At this time, since the popcorn ash collecting portion 81 has a plurality of projecting

portions

82, 83, the collecting area of the popcorn ash is increased, the pressure loss is reduced, and the popcorn ash is collected efficiently. be able to. As a result, damage to the popcorn ash collecting portion 81 due to popcorn ash is suppressed, and popcorn ash can be collected properly.

FIG. 11 is a schematic side view showing an exhaust gas processing system according to a fourth embodiment of the present invention. The members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted.

In the exhaust gas processing apparatus of the fourth embodiment, a popcorn ash collecting portion 91 capable of collecting popcorn ash in exhaust gas is attached between the heat recovery portion and the harmful substance removing portion in the exhaust gas pipe 48 by

brackets

92, 93 The popcorn ash collecting portion 91 is configured to be juxtaposed along the two directions in which the plurality of projecting portions 94 intersect, as in the first to third embodiments described above.

That is, the exhaust gas pipe 48 is configured such that the first pipe 48 a and the second pipe 48 b communicate with each other, and the hopper 62 is provided below the communication portion. The popcorn ash collecting portion 91 is provided to be inclined to the inlet of the second pipe 48b so as to be located downstream of the hopper 62 in the flow direction of the exhaust gas.

In the popcorn ash collecting portion 91, the plurality of projecting portions 94 project rearward (downstream side) in the flow direction of the exhaust gas. The popcorn ash collecting portion 91 is the same as the popcorn

ash collecting portions

61, 71, 81 of the embodiment 1-3 described above except for the projecting direction thereof, and the other configuration is the same. That is, what is necessary is just to arrange | position so that each

protrusion part

66, 72a, 72b, 82, 83 of popcorn

ash collection part

61, 71, 81 of Example 1-3 may protrude toward back in the flow direction of waste gas. It is.

As described above, in the exhaust gas processing apparatus of the fourth embodiment, as the popcorn ash collecting portion 91, the plurality of projecting portions 94 protruding to the downstream side in the flowing direction of the exhaust gas are arranged in parallel along two intersecting directions. There is.

Therefore, since the popcorn ash collecting portion 91 has the plurality of projecting portions 94, the collecting area of the popcorn ash is increased, the pressure loss is reduced, and the popcorn ash can be collected efficiently. . As a result, damage to the popcorn ash collection unit 91 due to popcorn ash is suppressed, and popcorn ash can be collected properly.

In addition, in each Example mentioned above, although the protrusion part was made into quadrangular pyramid shape or triangular pyramid shape, it is not limited to this shape. For example, it may be a polygonal pyramid shape such as pentagonal pyramid shape, a truncated pyramid shape, a spherical shape, a truncated cone shape, or the like. Moreover, although several protrusion parts were connected by the connection wire (connection part), it is good also considering a connection part as a plane. Furthermore, the protrusions may be randomly arranged.

Further, in each of the embodiments described above, the exhaust gas pipe 48 communicates the first pipe 48a extending along the vertical direction and the second pipe 48b extending along the horizontal direction, and the hopper 62 is formed there and configured Although the popcorn

ash collecting parts

61, 71, 81, 91 are provided at the inlet of the second pipe 48b, the present invention is not limited to this configuration. For example, the exhaust pipe 48 includes a first pipe (first passage) extending along the vertical direction, a second pipe (first passage) extending along the horizontal direction, and a third pipe (third path) extending along the vertical direction. Alternatively, a hopper may be formed in each communicating portion to communicate with the second passage, and a popcorn ash collecting portion may be provided at the inlet of the third pipe.

DESCRIPTION OF SYMBOLS 10 pulverized coal burning boiler 11

furnace

22, 22, 23, 24, 25 combustion burner 40

flue

41, 42 superheater (heat recovery part)
43, 44 reheater (heat recovery unit)
45, 46, 47 Charcoal (heat recovery unit)
48 Exhaust gas pipe (exhaust gas passage)
50 Selective reduction type catalyst (hazard removal part)
51 Electric precipitator (hazard removal part)
53 Desulfurization unit (hazard removal part)
61, 71, 81, 91 Popcorn ash collecting section 62 hopper 65 kicker (guide section)
66, 72a, 72b, 82, 83, 94

Protrusions

67a, 67b, 67c, 67d, 84a, 84b, 84c, 85a, 85b, 85c Inclined collection surfaces 68, 73, 86 Connections

Claims

An exhaust gas passage capable of flowing the combustion gas;
A heat recovery unit provided in the exhaust gas passage and capable of recovering the heat in the exhaust gas;
A harmful substance removing unit provided on the downstream side of the flow direction of the exhaust gas from the heat recovery unit in the exhaust gas passage and capable of removing harmful substances in the exhaust gas;
A popcorn ash collecting unit provided between the heat recovery unit and the harmful substance removing unit in the exhaust gas passage and capable of collecting popcorn ash in the exhaust gas;
Equipped with
The popcorn ash collecting portion is juxtaposed along two directions in which a plurality of projections projecting forward or backward in the flow direction of the exhaust gas intersect.
An exhaust gas processing apparatus characterized by
The connection portion to which the base end portions of the plurality of projecting portions are connected is continuously disposed at substantially the same position in the flow direction of the exhaust gas, and is inclined at a predetermined angle with respect to the horizontal direction. The exhaust gas processing apparatus according to 1.
The said connection part makes linear shape, The exhaust gas processing apparatus of Claim 2 characterized by the above-mentioned.
The exhaust gas treatment device according to any one of claims 1 to 3, wherein the protrusion has a polygonal pyramid shape.
The inclination angle with respect to the flow direction of the exhaust gas in the projecting portion disposed in the central portion of the exhaust gas passage is set smaller than the inclination angle with respect to the flow direction in the exhaust gas disposed in the outer peripheral portion of the exhaust gas passage. The exhaust gas processing apparatus according to claim 1, characterized in that
The exhaust gas passage has a first passage and a second passage connected in a direction substantially orthogonal to each other and connected along the flow direction of the exhaust gas, and the communication portion between the first passage and the second passage A hopper capable of storing popcorn ash is provided below, the heat recovery unit is provided upstream of the first passage or the first pipe, and the harmful substance is provided downstream of the second passage or the second pipe The exhaust gas processing apparatus according to claim 1, further comprising a removal unit, wherein the popcorn ash collecting unit is provided in the second passage.