JP5762255B2 - Exhaust gas treatment equipment - Google Patents

Description

  The present invention relates to an exhaust gas treatment apparatus applied to a boiler for generating steam for power generation or factory use.

  For example, a conventional pulverized coal-fired boiler has a furnace having a hollow shape and installed in a vertical direction, and a plurality of combustion burners are disposed on the furnace wall along the circumferential direction, and a plurality of stages in the vertical direction. Is arranged over. The combustion burner is supplied with an air-fuel mixture of pulverized coal (fuel) obtained by pulverizing coal and primary air, and also supplied with high-temperature secondary air, and blows the air-fuel mixture and secondary air into the furnace. This forms a flame and can be burned in this furnace. This furnace has a flue connected to the top, and this flue is provided with a superheater, reheater, economizer, etc. for recovering the heat of exhaust gas, and it was generated by combustion in the furnace. Heat exchange is performed between the exhaust gas and water, and steam can be generated. Further, this flue is connected to an exhaust gas passage, 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 the downstream end.

  In such a pulverized coal fired boiler, pulverized coal as fuel is burned in a furnace, so popcorn ash is mixed into the exhaust gas. Since this popcorn ash is a lump of ash, it particularly adheres to a denitration device provided in the exhaust gas passage, and the pressure loss increases, leading to 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. Examples of such a technique include those described in Patent Documents 1 and 2 below.

Japanese Patent No. 2724176 US Pat. No. 6,994,036

  As described above, the flue gas generated in the furnace of the boiler is mixed with popcorn ash, and this popcorn ash is a mass of ash of several millimeters to several tens of millimeters. On the other hand, the metal mesh provided in the exhaust gas passage has a mesh of several millimeters or less. For this reason, there is a problem that a large block of popcorn ash collides with a wire mesh or the like, so that the mesh of the wire mesh is locally clogged, worn or damaged.

  This invention solves the subject mentioned above, and aims at providing the waste gas processing apparatus which can collect popcorn ash appropriately.

  An exhaust gas treatment apparatus of the present invention for achieving the above object is provided with an exhaust gas passage having a bent portion and capable of flowing combustion gas, and provided upstream of the bent portion in the exhaust gas passage in the exhaust gas flow direction. A heat recovery part capable of recovering heat in the exhaust gas, a harmful substance removal part provided downstream of the bent part in the exhaust gas passage in the flow direction of the exhaust gas and capable of removing harmful substances in the exhaust gas, and the exhaust gas And a collecting part that is provided only on the outer peripheral side of the bent part in the passage and is capable of collecting popcorn ash in the exhaust gas.

  Therefore, the exhaust gas flowing through the exhaust gas passage collects the popcorn ash by the collection unit when the heat recovery unit recovers the heat and then passes through the bent portion, and then removes the harmful substance by the harmful substance removal unit. Is done. At this time, the popcorn ash in the exhaust gas passing through the bent portion flows on the outer peripheral side of the bent portion due to its inertial force, and is efficiently collected by the collecting portion provided on the outer peripheral side of the bent portion. On the other hand, the exhaust gas containing almost no popcorn ash passes through the opening without the collection part, and can properly collect the popcorn ash.

  In the exhaust gas treatment apparatus of the present invention, the exhaust gas passage has a first passage and a second passage communicating with each other in a direction substantially orthogonal to each other at the bent portion, and can store popcorn ash below the bent portion. A hopper is provided, and the collection part is provided on the second passage side from the hopper.

  Therefore, when the exhaust gas flows from the first passage to the bent second passage, the popcorn ash contained in the exhaust gas is efficiently collected by the collection unit, and then the collected popcorn ash is stored in the hopper. As a result, popcorn ash can be collected efficiently.

  In the exhaust gas treatment apparatus of the present invention, the collection unit covers an area of 30% to 70% of the passage area of the second passage.

  Therefore, by making the arrangement area of the collection part with respect to the passage area of the second passage an appropriate range, popcorn ash can be collected properly, while manufacturing cost can be reduced.

  The exhaust gas treatment apparatus of the present invention is characterized in that a guide portion for guiding exhaust gas to the outer peripheral side of the bent portion is provided on the inner peripheral portion of the bent portion.

  Therefore, when the exhaust gas flows from the first passage to the second passage, the exhaust gas is guided from the inner peripheral side to the outer peripheral side of the bent portion by the guide portion, and the exhaust gas is reduced by reducing the flow rate of the exhaust gas. The contained popcorn ash will be guided to the collection part side, and popcorn ash can be efficiently collected by this collection part.

  In the exhaust gas treatment apparatus of the present invention, the collection unit has a predetermined opening ratio set in advance, and is provided on the upstream side of the collection unit in the flow direction of the exhaust gas. A pre-stage collection unit having a high aperture ratio is provided.

  Therefore, since the exhaust gas flowing through the exhaust gas passage flows to the collection portion after the popcorn ash having a large particle size is removed by the upstream collection portion, damage to the second collection portion by the popcorn ash having a large particle size is suppressed, Popcorn ash can be collected properly.

  In the exhaust gas treatment apparatus of the present invention, the pre-stage collection unit includes a plurality of shielding plates that can drop when popcorn ash in the exhaust gas collides, and a predetermined interval in a direction intersecting the plurality of shielding plates with the flow direction of the exhaust gas. It is characterized by having a supporting member supported by.

  Accordingly, the popcorn ash in the exhaust gas collides with a plurality of shielding plates and falls in the upstream collection unit, thereby reducing the amount of popcorn ash flowing to the second collection unit, and the second collection by the popcorn ash. Damage to the part can be reduced.

  In the exhaust gas treatment apparatus of the present invention, the pre-stage collection unit is disposed along the vertical direction intersecting the flow direction of the exhaust gas and at a predetermined interval in the horizontal direction intersecting the flow direction of the exhaust gas so that popcorn ash in the exhaust gas is It has a plurality of shielding plates that can collide and fall.

  Accordingly, the popcorn ash in the exhaust gas collides with a plurality of shielding plates and falls in the upstream collection unit, thereby reducing the amount of popcorn ash flowing to the second collection unit, and the second collection by the popcorn ash. Damage to the part can be reduced.

  In the exhaust gas treatment apparatus of the present invention, the upstream collection unit is characterized in that the plurality of shielding plates are arranged in multiple stages along the flow direction of the exhaust gas.

  Therefore, since the flow of exhaust gas becomes a low pressure loss and the inertial force is weakened, popcorn ash can be reliably collected by the collecting portion.

  In the exhaust gas treatment apparatus of the present invention, the shielding plate has a mesh shape or a slit shape.

  Therefore, the amount of popcorn ash flowing to the second collection unit can be reduced with a simple configuration.

  According to the exhaust gas treatment apparatus of the present invention, since the collecting portion capable of collecting the popcorn ash in the exhaust gas is provided only on the outer peripheral side of the bent portion of the exhaust gas passage in the exhaust gas passage, the popcorn in the exhaust gas passing through the bent portion The ash flows on the outer peripheral side of the bent portion due to its inertial force, and popcorn ash can be efficiently collected by the collecting portion, while the exhaust gas containing almost no popcorn ash is an opening without a collecting portion. The popcorn ash can be collected properly.

FIG. 1 is a schematic configuration diagram illustrating a pulverized coal fired boiler to which an exhaust gas treatment apparatus according to Embodiment 1 of the present invention is applied. FIG. 2 is a schematic side view illustrating the exhaust gas treatment apparatus according to the first embodiment. FIG. 3 is a schematic plan view illustrating the exhaust gas treatment apparatus according to the first embodiment. FIG. 4 is a schematic diagram illustrating an exhaust gas treatment apparatus according to Embodiment 2 of the present invention. FIG. 5 is a perspective view illustrating a first collection unit in the exhaust gas treatment apparatus of the second embodiment. FIG. 6A is a schematic diagram illustrating a modification of the first collection unit in the exhaust gas treatment apparatus of the second embodiment. FIG. 6B is a schematic diagram illustrating a modification of the first collection unit in the exhaust gas treatment apparatus according to the second embodiment. FIG. 6-3 is a schematic diagram illustrating a modification of the first collection unit in the exhaust gas treatment apparatus according to the second embodiment. 6-4 is the schematic showing the modification of the 1st collection part in the exhaust gas processing apparatus of Example 2. FIG. FIG. 7 is a schematic diagram illustrating an exhaust gas treatment apparatus according to Embodiment 3 of the present invention. FIG. 8 is a schematic side view showing an exhaust gas treatment apparatus according to Embodiment 4 of the present invention. FIG. 9 is a schematic plan view illustrating an exhaust gas treatment apparatus of Example 4. FIG. 10-1 is a perspective view illustrating a first collection unit in an exhaust gas treatment apparatus according to Embodiment 4 of the present invention. 10-2 is a schematic diagram illustrating a modification of the first collection unit in the exhaust gas treatment apparatus of Example 4. FIG. 10-3 is the schematic showing the modification of the 1st collection part in the waste gas processing apparatus of Example 4. FIG.

  Exemplary embodiments of an exhaust gas treatment apparatus of the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  FIG. 1 is a schematic configuration diagram showing a pulverized coal fired boiler to which an exhaust gas treatment apparatus according to Embodiment 1 of the present invention is applied, FIG. 2 is a schematic side view showing an exhaust gas treatment apparatus of Embodiment 1, and FIG. 1 is a schematic plan view showing an exhaust gas treatment apparatus of Example 1. FIG.

  The pulverized coal fired boiler to which the exhaust gas treatment apparatus of Example 1 is applied can use pulverized coal obtained by pulverizing coal as a solid fuel, burn the pulverized coal with a combustion burner, and recover 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 includes a furnace 11 and a combustion device 12. The furnace 11 has a rectangular hollow shape and is installed along the vertical direction. A combustion device 12 is provided at the lower part of the furnace wall constituting the furnace 11.

  The combustion device 12 has a plurality of combustion burners 21, 22, 23, 24, 25 mounted on the furnace wall. In this embodiment, the combustion burners 21, 22, 23, 24, and 25 are arranged as four sets at equal intervals along the circumferential direction, and 5 sets along the vertical direction. Five stages are arranged.

  Each combustion burner 21, 22, 23, 24, 25 is connected to a pulverized coal machine (mill) 31, 32, 33, 34, 35 via a pulverized coal supply pipe 26, 27, 28, 29, 30. ing. Although not shown, the pulverized coal machines 31, 32, 33, 34, and 35 are supported in a housing so that the pulverization table can be driven to rotate with a rotation axis along the vertical direction, and face the upper side of the pulverization table. A plurality of crushing rollers are configured to be rotatably supported in conjunction with the rotation of the crushing table. Therefore, when coal is introduced between a plurality of crushing rollers and a crushing table, the pulverized coal supplied to the pulverized coal supply pipes 26 and 27 is pulverized to a predetermined size and classified by carrier air (primary air). , 28, 29, 30 can be supplied to the combustion burners 21, 22, 23, 24, 25.

  Further, the furnace 11 is provided with a wind box 36 at the mounting position of each combustion burner 21, 22, 23, 24, 25, and one end portion of an air duct 37 is connected to the wind box 36, and this air The duct 37 has a blower 38 attached to the other end. Accordingly, the combustion air (secondary air and tertiary air) sent by the blower 38 is supplied from the air duct 37 to the wind box 36, and the combustion burners 21, 22, 23, 24, 25 are supplied from the wind box 36. Can be supplied to.

  Therefore, in the combustion apparatus 12, each combustion burner 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. 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).

  In general, when the boiler is started, each combustion burner 21, 22, 23, 24, 25 injects oil fuel into the furnace 11 to form a flame.

  The furnace 11 has a flue 40 connected to the upper part, and a superheater (super heater) 41, 42 for recovering the heat of exhaust gas as a convection heat transfer part (heat recovery part) is connected to the flue 40. Heaters 43, 44 and economizers 45, 46, 47 are provided, and heat exchange is performed between the exhaust gas generated by combustion in the furnace 11 and water.

  The flue 40 is connected to an exhaust gas pipe (exhaust gas passage) 48 through which the exhaust gas subjected to heat exchange is discharged downstream. This exhaust gas pipe 48 is provided with an air heater 49 between 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 and 25 can be raised.

  Further, the exhaust gas pipe 48 is located upstream of the air heater 49 and is provided with a selective reduction type catalyst 50, and is located downstream of the air heater 49 and is provided with an electric dust collector 51, an induction blower 52, and a desulfurization device 53. A chimney 54 is provided at the downstream end. Here, the selective catalytic reduction catalyst 50, the electrostatic precipitator 51, and the desulfurization device 53 function as a harmful substance removing unit.

  Accordingly, when the pulverized coal machines 31, 32, 33, 34, and 35 are driven, the generated pulverized coal together with the conveying air passes through the pulverized coal supply pipes 26, 27, 28, 29, and 30 and the combustion burners 21, 22, 23, 24, 25. Also, heated combustion air is supplied from the air duct 37 to the combustion burners 21, 22, 23, 24, 25 via the wind box 36. Then, the combustion burners 21, 22, 23, 24, and 25 blow the pulverized fuel mixture mixed with the pulverized coal and the carrier air into the furnace 11 and blow 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. When a flame is generated in the lower part of the furnace 11, the combustion gas (exhaust gas) rises in the furnace 11, and the flue 40 is discharged.

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

  At this time, while water supplied from a water supply pump (not shown) is preheated by the economizers 45, 46 and 47, it is supplied to a steam drum (not shown) and supplied to each water pipe (not shown) on the furnace wall. Is heated to become saturated steam and fed into a steam drum (not shown). Further, saturated steam of a steam drum (not shown) is introduced into the superheaters 41 and 42 and is heated by the combustion gas. The superheated steam generated by the superheaters 41 and 42 is supplied to a power plant (not shown) such as a turbine. Further, the steam taken out in the middle of the expansion process in the turbine is introduced into the reheaters 43 and 44, overheated again, and returned to the turbine. In addition, although the furnace 11 was demonstrated as a drum type | mold (steam drum), it is not limited to this structure.

  Thereafter, the exhaust gas that has passed through the economizers 45, 46, and 47 of the flue 40 is subjected to removal of harmful substances such as NOx by the selective reduction catalyst 50 in the exhaust gas pipe 48, and particulate matter is removed by the electric dust collector 51. After the sulfur content is removed by the desulfurization device 53, it is discharged from the chimney 54 to the atmosphere.

  In the pulverized coal-fired boiler 10 configured in this way, the downstream side of the furnace 11 functions as the exhaust gas treatment apparatus of the first embodiment. In the exhaust gas treatment apparatus of Example 1, the heat recovery unit (superheaters 41 and 42, reheaters 43 and 44, economizers 45, 46, and 47) and the harmful substance removal unit (selective reduction) in the exhaust gas pipe 48 are used. A popcorn ash collecting part (collecting part) 60 capable of collecting popcorn ash in the exhaust gas is provided between the mold catalyst 50, the electric dust collector 51, and the desulfurization device 53). The exhaust gas pipe 48 is provided only on the outer peripheral side of the bent portion.

  That is, as shown in FIGS. 2 and 3, the exhaust pipe 48 has, for example, a first pipe (first passage) 48 a having a rectangular cross section and 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 perpendicular to each other, and a bent portion 61 is provided at the communication portion. In this case, a heat recovery part is provided on the first pipe 48a side located upstream in the flow direction of the exhaust gas, and a harmful substance removal part is provided on the second pipe 48b side located downstream in the flow 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 60 is provided in the 2nd piping 48b side.

  The first pipe 48 a and the second pipe 48 b have a rear end portion and a front end portion communicating with each other at the bent portion 61, and a hopper 62 capable of storing popcorn ash is provided below the bent portion 61. Yes. The hopper 62 is formed by inclined surfaces that face each other so that the area becomes narrower 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 the popcorn ash that has been collected and dropped by the popcorn ash collection unit 60, but also allows the popcorn ash to be discharged downward by opening the opening with an opening / closing valve (not shown). It has become. And the popcorn ash collection part 60 is provided in the inlet part of the 2nd piping 48b in the downstream of the flow direction of waste gas from the hopper 62. As shown in FIG.

  The popcorn ash collection part 60 is erected so as to extend substantially upward in the vertical direction from the bottom at the inlet of the second pipe 48b extending along the horizontal direction. And this popcorn ash collection part 60 is arranged in the whole area in the left-right direction (width direction), and the entrance part of the 2nd piping 48b is provided only in the lower part in the up-and-down direction (height direction), An opening 63 is provided in the upper part. In this case, the popcorn ash collection part 60 preferably covers an area (height) of 30% to 70% of the passage area of the second pipe 48b (height of the second pipe 48b), and the second pipe 48b. It is optimal to cover an area of 50% to 60% of the passage area.

  Moreover, the popcorn ash collection part 60 is formed of, for example, a mesh-shaped wire net and includes a large number of openings of 2 mm to 3 mm or less. Note that the popcorn ash collection unit 60 is not limited to a mesh-like wire mesh, and may be a screen or a porous body having a vertical slit or a horizontal slit.

  Further, a kicker (guide portion) 64 for guiding the exhaust gas to the outer peripheral side of the bent portion 61 is provided on the inner peripheral portion of the bent portion 61 of the first pipe 48 a and the second pipe 48 b. The kicker 64 protrudes from the inner wall surface of the lower end portion of the first pipe 48a toward the opposite inner wall surface side outside the bent portion 61 inside the bent portion 61 of the first pipe 48a and the second pipe 48b. The cross section has a tapered triangular shape.

  Here, the operation of the exhaust gas treatment apparatus of Example 1 will be described. After the exhaust gas flowing through the exhaust gas pipe 48 is recovered by the heat recovery unit (superheaters 41 and 42, reheaters 43 and 44, economizers 45, 46, and 47, see FIG. 1), the first It flows downward along the pipe 48a. Then, the exhaust gas bends at a substantially right angle at the communication part and flows into the popcorn ash collection part 60.

  Here, the exhaust gas is guided to the center side of the bent portion 61 by the kicker 64 inside the bent portion 61 of the first pipe 48a and the second pipe 48b, so that the flow is separated and the flow velocity is reduced. To do. And since the exhaust gas flows from the first pipe 48a through the bent portion 61 to the second pipe 48b, this exhaust gas is caused by popcorn ash passing through the bent portion 61 on the outer peripheral side of the bent portion 61 due to its inertial force. It will flow. Therefore, the popcorn ash flowing along with the exhaust gas on the outer peripheral side of the bent portion 61 is efficiently collected by the popcorn ash collecting portion 60 disposed at this position, while the popcorn ash flowing on the inner peripheral portion side of the bent portion 61 is collected. Exhaust gas containing almost no gas passes through the opening 63.

  Although the popcorn ash collected by the popcorn ash collection unit 60 adheres by a predetermined amount, the popcorn ash is dropped and stored in the hopper 62 by its own weight. Even if the popcorn ash is collected in the popcorn ash collection unit 60 and temporarily clogged, the popcorn ash in the exhaust gas collides with the clogged popcorn ash collection unit 60 and falls to the hopper 62. On the other hand, the exhaust gas containing almost no popcorn ash passes through the opening 63, and the pressure loss at this position is reduced.

  Thereafter, the exhaust gas from which the popcorn ash has been removed by the popcorn ash collection unit 60 is removed by the harmful substance removal unit (selective reduction catalyst 50, electrostatic precipitator 51, desulfurization device 53, see FIG. 1 above). .

  As described above, in the exhaust gas treatment apparatus of the first embodiment, the exhaust gas pipe 48 that has the bent portion 61 and can flow the combustion gas, and the heat recovery that is provided in the exhaust gas pipe 48 and can recover the heat in the exhaust gas. Only on the outer peripheral side of the bent portion 61 in the exhaust gas pipe 48, the harmful substance removal part that is provided downstream of the heat recovery part in the exhaust gas pipe 48 in the flow direction of the exhaust gas and can remove harmful substances in the exhaust gas There is provided a popcorn ash collection unit 60 that is provided and capable of collecting popcorn ash in the exhaust gas.

  Therefore, when the exhaust gas flowing through the exhaust gas pipe 48 passes through the bent portion 61 after heat is recovered by the heat recovery portion, the popcorn ash collection portion 60 collects the popcorn ash, and then the harmful substance removal portion. To remove harmful substances. At this time, the exhaust gas passing through the bent portion 61 causes the popcorn ash in the exhaust gas to flow on the outer peripheral side of the bent portion 61 due to its inertial force, and the popcorn ash trap provided on the outer peripheral portion side of the bent portion 61. While being efficiently collected by the collecting unit 60, the exhaust gas containing almost no popcorn ash passes through the opening 63 without the popcorn ash collecting unit 60, and can appropriately collect the popcorn ash.

  In the exhaust gas treatment apparatus of Example 1, the exhaust pipe 48 is provided with the first pipe 48a and the second pipe 48b that communicate with each other at the bent portion 61 in a direction substantially orthogonal to each other, and is located upstream of the exhaust gas flow direction. The first pipe 48a is provided with a heat recovery part, the second pipe 48b located downstream in the exhaust gas flow direction is provided with a harmful substance removal part, and a hopper 62 capable of storing popcorn ash is provided below the bent part 61. The popcorn ash collection part 60 is provided on the second pipe 48b side. Therefore, when the exhaust gas flows from the first pipe 48a through the bent portion 61 to the second pipe 48b, the popcorn ash contained in the exhaust gas is collected by the popcorn ash collection unit 60 and then stored in the hopper 62. As a result, popcorn ash can be collected efficiently.

  Further, in the exhaust gas treatment apparatus of Example 1, the popcorn ash collection unit 60 covers an area of 30% to 70% of the passage area of the second pipe 48a. Therefore, popcorn ash can be properly collected by setting the arrangement area of the popcorn ash collection portion 60 relative to the passage area of the second pipe 48a to an appropriate range, while popcorn ash is collected in an unnecessary portion. By eliminating the arrangement of the portion 60, the manufacturing cost can be reduced.

  In the exhaust gas treatment apparatus of the first embodiment, the kicker 64 that guides the exhaust gas to the outside of the corner is provided inside the bent portion 61 of the first pipe 48a and the second pipe 48b. Therefore, when the exhaust gas flows from the first pipe 48a to the second pipe 48b, the exhaust gas is guided from the inner peripheral side to the outer peripheral side of the bent portion 61 by the kicker 64, thereby reducing the flow rate of the exhaust gas. Then, the popcorn ash contained in the exhaust gas is guided to the popcorn ash collection unit 60 side, and the popcorn ash collection unit 60 can efficiently collect the popcorn ash.

4 is a schematic view showing an exhaust gas treatment apparatus according to Embodiment 2 of the present invention, FIG. 5 is a perspective view showing a first collection part in the exhaust gas treatment apparatus of Embodiment 2, and FIGS. 4 is a schematic diagram illustrating a modified example of the first collection unit in the exhaust gas treatment apparatus of Example 2. FIG. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  In the exhaust gas treatment apparatus of the second embodiment, as shown in FIGS. 4 and 5, the popcorn ash collection unit capable of collecting the popcorn ash in the exhaust gas between the heat recovery unit and the harmful substance removal unit in the exhaust gas pipe 48. 70 is provided, and the popcorn ash collection unit 70 includes a first collection unit (pre-stage collection unit) 71 having a high aperture ratio and a second collection unit (collection unit) 72 having a low aperture ratio. It consists of and. And the hopper 74 is provided under the bending part 73 of the 1st piping 48a and the 2nd piping 48b, and the 1st collection part 71 and the 2nd collection part 72 are the inlet_port | entrance part in the 2nd piping 48b, In other words, it is disposed close to the hopper 74. In addition, a kicker (guide portion) 75 that guides exhaust gas to the outer peripheral side of the bent portion 73 is provided on the inner peripheral portion of the bent portion 73 of the first pipe 48 a and the second pipe 48 b.

  The first collection unit 71 includes a plurality of shielding plates 76 that can collide and drop popcorn ash in the exhaust gas, and a support member that supports the plurality of shielding plates 76 at a predetermined interval in a direction intersecting the flow direction of the exhaust gas. 77. That is, the support member 77 has a bar shape along the vertical direction, and a plurality of support members 77 are arranged at predetermined intervals in the left-right direction, and the upper end portion and the lower end portion are fixed to the inner wall surface of the inlet portion of the second pipe 48b. The shielding plate 76 has a plate material shape having a predetermined size, and has a rectangular shape that is long in the left-right direction. The plurality of shielding plates 76 are fixed at a predetermined interval in the longitudinal direction of each support member 77. As a result, each shielding plate 76 is planar with a predetermined gap in the passage cross-sectional direction of the second pipe 48b. Will be placed. In this case, the vertical interval and the horizontal interval between the shielding plates 76 may be set as appropriate, and may be set narrowly according to the particle size of the popcorn ash in the exhaust gas.

  On the other hand, the second collection part 72 is provided only on the outer peripheral side of the bent part 73 in the exhaust gas pipe 48. That is, the second collection part 72 is erected so as to extend substantially upward in the vertical direction from the bottom part at the inlet part of the second pipe 48b extending along the horizontal direction. And this 2nd collection part 72 is arranged in the whole area in the left-right direction (width direction), and the entrance part of the 2nd piping 48b is provided only in the lower part in the up-and-down direction (height direction), An opening 78 is provided in the upper part. In this case, the second collection part 72 preferably covers an area (height) of 30% to 70% of the passage area (height of the second pipe 48b) of the second pipe 48b, and the second pipe 48b. It is optimal to cover an area of 50% to 60% of the passage area.

  Therefore, when the exhaust gas reaches the popcorn ash collection unit 70, first, the popcorn ash having a large particle size collides and falls by the first collection unit 71 having a high aperture ratio, and then is collected. The popcorn ash having a small particle diameter is collected by the second collecting part 72 having a low particle size. Therefore, since the flue gas flows to the second collecting part 72 after the popcorn ash having a large particle diameter is removed by the first collecting part 71, there is almost no popcorn ash having a large particle diameter flowing to the second collecting part 72. The damage of the 2nd collection part 72 by this popcorn ash with this large particle size is suppressed.

  In addition, the flow is peeled off and the flow velocity is lowered by being guided to the center side of the bent portion 73 by the kicker 75 inside the bent portion 73 of the first pipe 48a and the second pipe 48b. Since the exhaust gas flows from the first pipe 48a through the bent portion 73 to the second pipe 48b, the exhaust gas has a faster flow rate on the outer peripheral side than on the inner peripheral side of the bent portion 73. Thus, the popcorn ash in the exhaust gas flows on the outer peripheral side of the bent portion 73 due to its inertial force. Therefore, after the popcorn ash having a large particle size is removed by the first collecting unit 71, the exhaust gas containing the popcorn ash having a small particle size is efficiently collected by the second collecting unit 72 arranged at this position. The

  In addition, the shape of the 1st collection part 71 is not limited to this shape. For example, as illustrated in FIG. 6A, the first collection unit 81 includes a plurality of shielding plates 82 and a support member 83 that supports the plurality of shielding plates 82 at a predetermined interval. That is, the support member 83 has a bar shape along the vertical direction. The shielding plate 82 has a shape obtained by bending a plate material of a predetermined size at a central portion in the left-right direction at a predetermined angle. The plurality of shielding plates 82 are fixed at predetermined intervals in the longitudinal direction of the support member 83. In this case, each shielding plate 82 is bent in the direction opposite to the flow direction of the exhaust gas, and the support member 83 to which the central portion of the shielding plate 82 is fixed also has a bent (V-shaped) cross-sectional shape. However, it may be a simple bar having a rectangular cross section.

  Further, as shown in FIG. 6B, the first collection unit 91 includes a plurality of shielding plates 92 and a support member 93 that supports the plurality of shielding plates 92 at a predetermined interval. That is, the support member 93 has a bar shape along the vertical direction. The shielding plate 92 has a shape obtained by bending a plate material having a predetermined size. The plurality of shielding plates 92 are fixed at predetermined intervals in the longitudinal direction of the support member 93. In this case, each shielding plate 92 is curved in the direction opposite to the flow direction of the exhaust gas, and the support member 93 to which the central portion of the shielding plate 92 is fixed also has a curved (U-shaped) cross-sectional shape. However, it may be a simple bar having a rectangular cross section.

  Moreover, as shown to FIGS. 6-3, the 1st collection part 101 is comprised from the several shielding board 102 and the supporting member 103 which supports this several shielding board 102 by predetermined spacing. That is, the support member 103 has a bar shape along the vertical direction. The shielding plate 102 has a shape in which a plate material of a predetermined size is bent at a predetermined angle at the center in the left-right direction. The plurality of shielding plates 102 are fixed at predetermined intervals in the longitudinal direction of the support member 103. In this case, each shielding plate 102 is bent toward the flow direction of the exhaust gas.

  In addition, the shape of each shielding board 76, 82, 92, 102 is not limited to these. However, popcorn ash contained in the exhaust gas can be efficiently collected when bent or curved in the direction opposite to the flow direction of the exhaust gas, such as the shielding plates 82 and 92. On the other hand, when bent or bent in the flow direction of the exhaust gas as in the shielding plate 101, the popcorn ash contained in the exhaust gas can be efficiently collected and the flow resistance of the exhaust gas is reduced to reduce the pressure loss. Can be reduced.

  Further, the arrangement of the shielding plates 76, 82, 92, 102 in the first collection parts 71, 81, 91, 101 is not limited to this embodiment. For example, as illustrated in FIG. 6-4, the first collection unit 106 includes a front collection unit 106 a and a rear collection unit 106 b that are arranged at predetermined intervals in the front and rear in the flow direction of the exhaust gas. . The front collection unit 106a and the rear collection unit 106b have substantially the same configuration, and include a plurality of shielding plates 107 and a support member 108 that supports the plurality of shielding plates 107 at a predetermined interval. . However, in the front collection part 106a and the rear collection part 106b, the positions of the shielding plates 107 are shifted in the horizontal direction and the vertical direction. In addition, although the 1st collection part 106 was made into 2 steps front and back arrangement | positioning, you may arrange | position 3 steps arrangement | positioning or at random. Such an arrangement may be not only the first collection unit 106 but also the first collection units 71, 81, 91, 101.

  Thus, in the exhaust gas treatment apparatus of Example 2, as the popcorn ash collection unit 70, the first collection units 71, 81, 91, 101 having a high aperture ratio and the first collection units 71, 81, A second collection portion 72 having an opening ratio lower than the opening ratio of 91, 101 is provided, and a plurality of shields capable of colliding and dropping popcorn ash in the exhaust gas as the first collection portions 71, 81, 91, 101 are provided. While providing the plates 76, 82, 92, 102 and the support members 77, 83, 93, 103 for supporting the plurality of shielding plates 76, 82, 92, 102 at predetermined intervals in the direction intersecting the flow direction of the exhaust gas, The second collection part 72 is provided only on the outer peripheral side of the bent part 73 in the exhaust gas pipe 48.

  Accordingly, the popcorn ash in the exhaust gas collides with the plurality of shielding plates 76, 82, 92, 102 and falls on the hopper 74 in the first collection parts 71, 81, 91, 101, and is collected. The amount of popcorn ash flowing to the second collection unit 102 can be reduced, and damage to the second collection unit 72 due to popcorn ash can be reduced. Further, the exhaust gas passing through the bent portion 73 causes the popcorn ash in the exhaust gas to flow on the outer peripheral side of the bent portion 73 due to its inertial force, and the second collection provided on the outer peripheral portion side of the bent portion 73. The portion 72 can be efficiently collected.

  FIG. 7 is a schematic diagram illustrating an exhaust gas treatment apparatus according to Embodiment 3 of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  In the exhaust gas treatment apparatus of the third embodiment, as shown in FIG. 7, the exhaust gas pipe 48 includes a first pipe (first passage) 48a extending along the vertical direction and a second pipe (first pipe) extending along the horizontal direction. 48b and a third pipe (second passage) 48c extending in the vertical direction are configured to communicate with each other in a direction substantially perpendicular to each other, and is located on the first pipe 48a side located upstream in the flow direction of the exhaust gas. Is provided with a heat recovery part, and a harmful substance removal part is provided on the third pipe 48c located downstream in the flow direction of the exhaust gas. A first hopper 111 is provided below the communication portion between the first pipe 48a and the second pipe 48b, and a second hopper 112 is provided below the communication portion between the second pipe 48b and the third pipe 48c. Yes.

  And the popcorn ash collection part 113 which can collect the popcorn ash in exhaust gas is provided between the heat recovery part and the harmful substance removal part in the exhaust gas pipe 48, and the popcorn ash collection part 113 has a high opening. 1st collection part (pre-stage collection part) 114 which has a rate, and 2nd collection part 115 (collection part) which has a low aperture ratio. In the present embodiment, the popcorn ash collection unit 113 is provided on the third pipe 48c side. That is, in the first pipe 48a, exhaust gas flows downward in the interior, in the second pipe 48b, exhaust gas flows horizontally in the interior, and in the third pipe 48c, the exhaust gas flows upward in the interior, The popcorn ash collection unit 113 including the first collection unit 114 and the second collection unit 115 is an inlet of the third pipe 48 c and is disposed above the second hopper 112.

  The second collection unit 115 is provided only on the outer peripheral side of the bent portion 116 in the exhaust gas pipe 48. That is, the second collection portion 115 is provided so as to extend substantially horizontally from the wall portion on the outer peripheral side of the bent portion 116 at the inlet portion of the third pipe 48c extending along the vertical direction. And this 2nd collection part 115 is arrange | positioned in the horizontal direction (width direction) all over the inlet part of the 3rd piping 48c, and is provided in only one side in the horizontal direction, and it is an opening part in the other side. 117 is provided.

  In addition, since the structure of the popcorn ash collection part 113 (the 1st collection part 114, the 2nd collection part 115) has comprised the structure substantially the same as Example 2 mentioned above, detailed description is abbreviate | omitted. .

  Accordingly, when the exhaust gas passes from the first pipe 48a through the second pipe 48b to the popcorn ash collection section 113 of the third pipe 48c, first, the popcorn ash having a large particle size is formed by the first collection section 114 having a high aperture ratio. Next, popcorn ash having a small particle diameter is collected by the second collection unit 115 having a low aperture ratio. Therefore, since the exhaust gas flows to the second collection unit 115 after the popcorn ash having a large particle size is removed by the first collection unit 114, there is almost no popcorn ash having a large particle size that flows to the second collection unit 115. The damage of the second collection unit 115 due to the popcorn ash having a large particle size is suppressed.

  Further, since the exhaust gas flows from the first pipe 48a through the bent portion 116 to the third pipe 48c, the exhaust gas is caused by popcorn ash at the bent portion 116 at the outer peripheral portion side of the bent portion 116 due to its inertial force. It will flow. Therefore, after the popcorn ash having a large particle size is removed by the first collection unit 114, the exhaust gas containing the popcorn ash having a small particle size is efficiently collected by the second collection unit 115 disposed at this position. The

  Further, the popcorn ash collected by the first collection unit 114 and the second collection unit 115 falls and is stored in the second hopper 112, but the first collection unit 114 from the second collection unit 115. Since the opening ratio is higher, the popcorn ash collected by the second collection unit 115 passes through the first collection unit 114 and falls to the second hopper 112 to be stored.

  Thus, in the exhaust gas treatment apparatus of Example 3, the popcorn ash collection part 113 is provided at the inlet part (lower end part) of the third pipe 48c along the vertical direction in the exhaust gas pipe 48, and this popcorn ash collection part. As the section 113, a first collection section 114 having a high aperture ratio and a second collection section 115 having an aperture ratio lower than that of the first collection section 114 are provided, and the second collection section 115 is connected to the exhaust gas pipe 48. Are provided only on the outer peripheral side of the bent portion 116.

  Accordingly, after the heat flowing through the exhaust gas pipe 48 is recovered by the heat recovery unit, the popcorn ash having a large particle diameter is collected by the first collection unit 114 having a high aperture ratio in the third pipe 48c, The popcorn ash having a small particle diameter is collected by the second collection unit 115 having a low aperture ratio, and then the harmful substance is removed by the harmful substance removal unit. Therefore, the exhaust gas containing popcorn ash having a large particle size hardly flows into the second collecting unit 115, and clogging, wear, and damage to the second collecting unit 115 due to the popcorn ash having a large particle size are suppressed. , Popcorn ash can be collected properly at all times. Further, the exhaust gas passing through the bent portion 116 causes the popcorn ash in the exhaust gas to flow on the outer peripheral side of the bent portion 116 due to its inertial force, and the second collection provided on the outer peripheral portion side of the bent portion 116. The portion 115 can be efficiently collected.

  8 is a schematic side view showing an exhaust gas treatment apparatus according to Example 4 of the present invention, FIG. 9 is a schematic plan view showing an exhaust gas treatment apparatus of Example 4, and FIG. 10-1 is Example 4 of the present invention. FIG. 10-2 and FIG. 10-3 are schematic views illustrating a modification of the first collection unit in the exhaust gas treatment apparatus according to the fourth embodiment. In addition, the same code | symbol is attached | subjected to the member which has the function similar to the Example mentioned above, and detailed description is abbreviate | omitted.

  In the exhaust gas treatment apparatus of Example 4, as shown in FIGS. 8 and 9, the popcorn ash collector that can collect the popcorn ash in the exhaust gas between the heat recovery unit and the harmful substance removal unit in the exhaust gas pipe 48. 120 is provided, and the popcorn ash collection unit 120 includes a first collection unit (pre-stage collection unit) 121 having a high aperture ratio and a second collection unit (collection unit) 122 having a low aperture ratio. It consists of and. And the hopper 124 is provided below the bending part 123 of the 1st piping 48a and the 2nd piping 48b, and the 1st collection part 121 and the 2nd collection part 122 are the entrance parts in the 2nd piping 48b, That is, it is arranged close to the hopper 124. Further, a kicker (guide portion) 125 that guides the exhaust gas to the outer peripheral side of the bent portion 123 is provided on the inner peripheral portion of the bent portion 123 of the first pipe 48 a and the second pipe 48 b.

  The 1st collection part 121 has the front part collection part 121a and the rear part collection part 121b which are arrange | positioned at predetermined intervals before and behind in the flow direction of exhaust gas. The front collection unit 121a and the rear collection unit 121b have substantially the same configuration, and are configured by a plurality of shielding plates 131 that can collide and drop popcorn ash in exhaust gas. As shown in FIGS. 9 and 10-1, the shielding plates 131 are arranged along the vertical direction intersecting the flow direction of the exhaust gas and at a predetermined interval in the horizontal direction intersecting the flow direction of the exhaust gas. The popcorn ash inside can collide and drop. That is, the shielding plate 131 has a V-shape obtained by bending a plate material having a predetermined length at a central portion in the left-right direction at a predetermined angle. And the some shielding board 131 is arrange | positioned along the perpendicular direction, and is arrange | positioned at predetermined intervals in the horizontal direction. In this case, in the front collection part 121a and the rear collection part 121b, the horizontal arrangement positions on the shielding plates 131 are staggered (staggered). In addition, as the 1st collection part 121, although it was set as 2 steps front-and-back arrangement | positioning by providing the front part collection part 121a and the rear part collection part 121b, you may arrange | position 3 steps | paragraphs or more randomly.

  On the other hand, as shown in FIGS. 8 and 9, the second collection portion 122 is provided only on the outer peripheral portion side of the bent portion 123 in the exhaust gas pipe 48. That is, the second collection part 122 is erected so as to extend substantially upward in the vertical direction from the bottom at the inlet of the second pipe 48b extending along the horizontal direction. And this 2nd collection part 122 is arranged in the whole area in the horizontal direction (width direction), and the entrance part of the 2nd piping 48b is provided only in the lower part in the up-and-down direction (height direction). An opening 126 is provided at the top.

  Therefore, when the exhaust gas reaches the popcorn ash collection unit 120, first, the popcorn ash having a large particle size collides and falls by the first collection unit 121 having a high aperture ratio, and then the aperture ratio is collected. The popcorn ash having a small particle diameter is collected by the second collecting part 122 having a low particle size. Therefore, since the exhaust gas flows to the second collection unit 122 after the popcorn ash having a large particle size is removed by the first collection unit 121, there is almost no popcorn ash having a large particle size that flows to the second collection unit 122. The damage of the 2nd collection part 122 by this popcorn ash with this large particle size is suppressed.

  In addition, the flow is peeled off and the flow velocity is lowered by being guided to the center side of the bent portion 123 by the kicker 125 inside the bent portion 123 of the first pipe 48a and the second pipe 48b. Since the exhaust gas flows from the first pipe 48a through the bent portion 123 to the second pipe 48b, the exhaust gas has a faster flow rate on the outer peripheral side than on the inner peripheral side of the bent portion 123. Thus, the popcorn ash in the exhaust gas flows on the outer peripheral side of the bent portion 123 due to its inertial force. Therefore, after the popcorn ash having a large particle size is removed by the first collecting unit 121, the exhaust gas containing the popcorn ash having a small particle size is efficiently collected by the second collecting unit 122 disposed at this position. The

  In addition, the shape of the 1st collection part 121 (front part collection part 121a, rear part collection part 121b) is not limited to this shape. For example, as shown in FIG. 10-2, a plate member having a predetermined length may be used as a shielding plate 132 having a curved shape. In this case, the shielding plate 132 is curved in the direction opposite to the flow direction of the exhaust gas. Moreover, as shown in FIG. 10-3, it is good also as the shielding board 133 which makes | forms the shape which bent the board | plate material of predetermined length in the center part in the left-right direction at the predetermined angle. In this case, the shielding plate 133 is bent toward the flow direction of the exhaust gas.

  In addition, the shape of each shielding board 131,132,133 is not limited to these. However, as in the case of the shielding plates 132 and 132, when bent or curved in the direction opposite to the flow direction of the exhaust gas, popcorn ash contained in the exhaust gas can be efficiently collected. On the other hand, when bent or curved toward the flow direction of the exhaust gas, like the shielding plate 133, the popcorn ash contained in the exhaust gas can be efficiently collected and the flow resistance of the exhaust gas is reduced to reduce pressure loss. Can be reduced.

  Thus, in the exhaust gas treatment apparatus of Example 4, the popcorn ash collection unit 120 has a first collection unit 121 having a high aperture ratio and an aperture ratio lower than the aperture ratio of the first collection unit 121. A second collection unit 122 is provided, and the first collection unit 121 includes a front collection unit 121a and a rear collection unit having a plurality of shielding plates 131, 132, and 133 that can collide and drop popcorn ash in exhaust gas. While providing the part 121 b, the second collection part 122 is provided only on the outer peripheral side of the bent part 123 in the exhaust gas pipe 48.

  Therefore, the popcorn ash in the exhaust gas collides with the plurality of shielding plates 131, 132, 133 and falls on the hopper 124 at the first collection unit 121, and is collected and flows to the second collection unit 122. The amount of ash can be reduced, and damage to the second collection unit 122 due to popcorn ash can be reduced. Further, the exhaust gas passing through the bent portion 123 causes the popcorn ash in the exhaust gas to flow on the outer peripheral side of the bent portion 123 due to its inertial force, and the second collection provided on the outer peripheral portion side of the bent portion 123. The part 122 can be efficiently collected.

  Further, in the exhaust gas treatment apparatus of Example 4, a front collection unit 121a and a rear collection unit 121b are provided as the first collection unit 121 and are arranged in a front and rear two-stage arrangement. Therefore, since the flow of exhaust gas becomes a low-pressure loss and the inertial force is weakened, the popcorn ash collecting unit 120 can reliably collect the popcorn ash.

  In the second and fourth embodiments described above, the shielding plates 76, 82, 92, 102 of the first collection units 71, 81, 91, 101 and the shielding plates 131, 132, 133 of the first collection unit 121 are plates. However, the present invention is not limited to this, and may be a mesh-like wire mesh, a screen having vertical slits or horizontal slits, or the like.

  Moreover, in Example 1, 2, and 4 mentioned above, the popcorn ash collection parts 60 and 70 are provided in the entrance side of the 2nd piping 48b, and in Example 3, the popcorn ash collection part 113 is provided in the entrance of the 3rd piping 48c. Although it provided in the side, it is not limited to this position. For example, it may be provided not in the bent portion of the pipe but in the straight portion, and a plurality of first and second collecting portions may be provided.

10 Pulverized coal fired boiler 11 Furnace 21, 22, 23, 24, 25 Combustion burner 40 Flue 41, 42 Superheater (heat recovery part)
43, 44 Reheater (Heat recovery part)
45, 46, 47 Energy-saving equipment (heat recovery part)
48 Exhaust gas pipe (exhaust gas passage)
50 selective reduction catalyst (hazardous substance removal unit)
51 Electric dust collector (hazardous substance removal part)
53 Desulfurization equipment (hazardous substance removal section)
60 Popcorn ash collection part (collection part)
70, 113, 120 Popcorn ash collection part 61, 73, 116, 123 Bending part 62, 74, 124 Hopper 63, 78, 117, 126 Opening 64, 75, 125 Kicker (guide part)
71, 81, 91, 101, 106, 114, 121 1st collection part (front collection part)
72, 115, 122 Second collection part (collection part)
76, 82, 92, 102, 107, 131, 132, 133 Shield plate 77, 83, 93, 103, 108 Support member 111 First hopper 112 Second hopper

Claims (6)

An exhaust gas passage having a bent portion and capable of flowing combustion gas;
A heat recovery unit that is provided upstream of the bent portion in the exhaust gas passage in the flow direction of the exhaust gas and can recover the heat in the exhaust gas;
A hazardous substance removing portion that is provided downstream of the bent portion in the exhaust gas passage in the flow direction of the exhaust gas and capable of removing harmful substances in the exhaust gas;
A collecting part that is provided only on the outer peripheral side of the bent part in the exhaust gas passage and can collect popcorn ash in the exhaust gas;
Bei to give a,
The exhaust gas passage has a first passage and a second passage communicating with each other in a direction substantially orthogonal to each other at the bent portion, and a hopper capable of storing popcorn ash is provided below the bent portion, and the collecting The portion is provided on the second passage side from the hopper,
A guide part for guiding exhaust gas to the outer peripheral side of the bent part is provided on the inner peripheral part of the bent part,
The collection part has a predetermined opening ratio set in advance, is provided upstream of the collection part in the flow direction of exhaust gas, and has a higher opening ratio than the collection part. Part is provided,
The pre-stage collection unit is provided above the hopper and below the guide unit.
An exhaust gas treatment apparatus characterized by that. 2. The exhaust gas treatment apparatus according to claim 1 , wherein the collection unit covers an area of 30% to 70% of a passage area of the second passage. The pre-stage collection unit includes a plurality of shielding plates capable of colliding and dropping popcorn ash in the exhaust gas, and a support member that supports the plurality of shielding plates at a predetermined interval in a direction intersecting the flow direction of the exhaust gas. The exhaust gas treatment apparatus according to claim 1 or 2 , characterized by the above. The pre-stage collection unit is arranged along a vertical direction intersecting with the flow direction of the exhaust gas and arranged at a predetermined interval in a horizontal direction intersecting with the flow direction of the exhaust gas so that popcorn ash in the exhaust gas can collide and fall The exhaust gas treatment apparatus according to claim 1, further comprising a shielding plate. 5. The exhaust gas treatment apparatus according to claim 3 , wherein the upstream collecting unit includes the plurality of shielding plates arranged in multiple stages along a flow direction of the exhaust gas. The exhaust gas treatment apparatus according to any one of claims 3 to 5 , wherein the shielding plate has a mesh shape or a slit shape.

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