JP6429681B2 - Exhaust duct and boiler - Google Patents

Description

  The present invention relates to an exhaust duct applied to a boiler for generating steam for power generation or factory use, and a boiler having the exhaust duct.

  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 carrier air (primary air), and is also supplied with high-temperature secondary air. The flame is formed by blowing the gas into the furnace, and the combustion gas can be generated in the 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. Steam can be generated by heating water with the exhaust gas. 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.

  As such a boiler, there exists a thing described in the following patent document, for example.

US Pat. No. 6,994,036 JP2013-103214A

  In the pulverized coal-fired boiler described above, pulverized coal as fuel is burned in a furnace, and therefore, popcorn ash (bulk ash) as solid particles may be mixed into the exhaust gas. Since this popcorn ash is a lump of ash, there is a possibility that the screen or the denitration device provided in the exhaust gas passage may be blocked. When such a blockage occurs, the screen is worn and needs to be replaced, which increases the maintenance cost. Further, when popcorn ash is deposited on a screen or a denitration apparatus, pressure loss increases and performance is deteriorated.

  The present invention solves the above-described problems, and an object thereof is to provide an exhaust duct and a boiler that can appropriately collect solid particles in exhaust gas.

An exhaust duct of the present invention for achieving the above object includes an exhaust gas passage through which exhaust gas flows,
A hopper provided in the exhaust gas passage for collecting solid particles in the exhaust gas, and provided along the inner wall surface of the exhaust gas passage upstream or downstream in the flow direction of the exhaust gas with respect to the hopper, from the inner wall surface It has a low repulsion part with a small repulsion coefficient, and a tension | tensile_strength provision part which provides tension | tensile_strength to the said low repulsion part, It is characterized by the above-mentioned.

  Therefore, when exhaust gas flows through the exhaust gas passage, solid particles are separated from the exhaust gas and collected by the hopper. At this time, since the solid particles have an inertial force, they collide with the inner wall surface of the exhaust gas passage and are not collected by the hopper and are likely to flow out to the downstream side, but since the solid particles collide with the low repulsion part, Here, the amount of rebound decreases and is properly collected by the hopper. Moreover, the low repulsion part expand | swells by high temperature exhaust gas, and the repulsive force tends to fall, but since a tension | tensile_strength is provided by a tension | tensile_strength provision part, a repulsive force is always maintained. As a result, solid particles in the exhaust gas can be properly collected in the hopper, and the collection efficiency can be improved.

  In the exhaust duct of the present invention, the tension applying portion includes a support portion fixed to the inner wall surface, and a fixing portion provided so as to be fixed at an arbitrary position close to or separated from the inner wall surface with respect to the support portion. And supporting both ends of the low repulsion portion on the inner wall surface side, and moving a part of the low repulsion portion between the both ends together with the fixed portion from the inner wall surface to the low repulsion portion. It is characterized by applying tension.

  Therefore, the low repulsion part is given tension by the tension applying part, and the repulsive force is always maintained. As a result, solid particles in the exhaust gas can be properly collected in the hopper, and the collection efficiency can be improved.

  In the exhaust duct of the present invention, the tension applying portion is made of an elastic member, supports both ends of the low repulsion portion on the inner wall surface side, and urges a part of the low repulsion portion between both ends by an elastic force. Thus, a tension is applied to the low repulsion part.

  Therefore, the low repulsion part is given tension by the tension applying part, and the repulsive force is always maintained. As a result, solid particles in the exhaust gas can be properly collected in the hopper, and the collection efficiency can be improved.

  In the exhaust duct according to the aspect of the invention, the tension applying portion may be an expansion member having a linear expansion coefficient that is equal to or greater than that of the low repulsion portion, and the expansion member along the inner wall surface together with the low repulsion portion. One end side of both ends of the low repulsion portion attached is fixed to the inner wall surface and the other end side is disposed as a free end, and applies tension to the low repulsion portion by expansion. Yes.

  Therefore, the low repulsion part is given tension by the tension applying part, and the repulsive force is always maintained. As a result, solid particles in the exhaust gas can be properly collected in the hopper, and the collection efficiency can be improved.

  In the exhaust duct according to the present invention, the tension applying portion includes a weight, is attached to a lower end of the low repulsion portion whose upper end is fixed to the inner wall surface, and applies tension to the low repulsion portion by its own weight. It is said.

  Therefore, the low repulsion part is given tension by the tension applying part, and the repulsive force is always maintained. As a result, solid particles in the exhaust gas can be properly collected in the hopper, and the collection efficiency can be improved.

  In the exhaust duct of the present invention, the exhaust gas passage has a first vertical part in which exhaust gas flows downward in the vertical direction, and a horizontal part connected to the first vertical part, and the hopper includes the first vertical part. The low repulsion part and the tension applying part are upstream of the hopper in the flow direction of the exhaust gas, and are provided on a lower wall surface of the first vertical part. It is provided in the part.

  Therefore, when the low repulsion part is provided on the upstream side of the hopper, the solid particles contained in the exhaust gas collide with the low repulsion part before the hopper, so that the inertial force is reduced and the hopper becomes easy to enter. It is possible to reduce the amount of solid particles that jump over and scatter downstream.

  In the exhaust duct of the present invention, the low repulsion part has a low repulsion part inclined surface inclined in the same direction as the inclined surface of the hopper.

  Therefore, when the inclined surface of the low repulsion part is inclined in the same direction as the inclined surface of the hopper, when the solid particles contained in the exhaust gas collide with the low repulsion part, the solid particles are inclined from the inclined surface of the low repulsion part to the hopper inclination. It falls along the surface and is collected by the hopper, so that the solid particles can be properly guided to the hopper.

  In the exhaust duct of the present invention, the exhaust gas passage has a horizontal part in which the exhaust gas flows in the horizontal direction and a second vertical part connected to the horizontal part and in which the exhaust gas flows upward in the vertical direction. The low repulsion part and the tension applying part are provided in the lower part of the flow direction of the exhaust gas with respect to the hopper, and the horizontal part is opposed to the hopper. It is provided in the standing wall surface part in the said 2nd perpendicular part.

  Therefore, when the low repulsion part is provided downstream from the hopper, the solid particles contained in the exhaust gas pass through the upper part of the hopper and then collide with the low repulsion part. It is possible to reduce the amount of solid particles that jump over the hopper and scatter downstream.

  In the exhaust duct of the present invention, the low repulsion part is also provided on the inner wall surface of the hopper.

  Therefore, since the low repulsion part is also provided on the inner wall surface of the hopper, the low repulsion part appropriately reduces the inertial force of the solid particles to make it easy to enter the hopper, and the solid particles re-scatter from the hopper. Can be suppressed.

  The boiler according to the present invention is connected to a downstream furnace in a hollow shape and installed in the vertical direction, a combustion apparatus for injecting and burning fuel into the furnace, and a downstream side in the exhaust gas flow direction in the furnace The exhaust duct, and a heat recovery part provided in the exhaust duct and capable of recovering the heat in the exhaust gas.

  Therefore, a flame is formed by injecting fuel into the furnace by the combustion device, and the generated combustion gas flows into the exhaust duct, and the heat recovery unit recovers the heat in the exhaust gas, while the solid particles are separated from the exhaust gas and the hopper To be recovered. At this time, since the exhaust gas flowing through the exhaust gas passage is separated from the solid particles and collides with the low repulsion part, the amount of repulsion decreases here and is appropriately collected by the hopper. Moreover, the low repulsion part expand | swells by high temperature exhaust gas, and the repulsive force tends to fall, but since a tension | tensile_strength is provided by a tension | tensile_strength provision part, a repulsive force is always maintained. As a result, solid particles in the exhaust gas can be properly collected in the hopper, and the collection efficiency can be improved.

  According to the exhaust duct and the boiler of the present invention, the low repulsion part having a smaller coefficient of restitution than the inner wall surface of the exhaust gas passage is provided on the upstream side or the downstream side of the hopper, and the tension applying part for applying tension to the low repulsion part is provided. Therefore, it becomes possible to always maintain the function of the low repulsion part, so that solid particles in the exhaust gas can be properly collected in the hopper, and the collection efficiency can be improved.

FIG. 1 is a schematic configuration diagram showing a pulverized coal fired boiler to which an exhaust duct according to an embodiment of the present invention is applied. FIG. 2 is a side view showing the exhaust duct according to the embodiment of the present invention. FIG. 3 is a perspective view showing a low repulsion part in the exhaust duct. FIG. 4 is a perspective view showing another example of the low repulsion part in the exhaust duct. FIG. 5 is a schematic diagram showing the action of the low repulsion part. FIG. 6 is a schematic diagram showing the action of the low repulsion part. FIG. 7 is a schematic view showing a tension applying portion in the exhaust duct. FIG. 8 is a schematic diagram illustrating another example of the tension applying portion in the exhaust duct. FIG. 9 is a schematic diagram illustrating another example of the tension applying portion in the exhaust duct. FIG. 10 is a schematic diagram illustrating another example of the tension applying portion in the exhaust duct. FIG. 11 is a schematic diagram illustrating another example of the tension applying portion in the exhaust duct. FIG. 12 is a perspective view illustrating another example of the tension applying portion in the exhaust duct. FIG. 13 is a schematic diagram illustrating another example of the tension applying portion in the exhaust duct. FIG. 14 is a perspective view illustrating another example of the tension applying portion in the exhaust duct. FIG. 15 is a side view illustrating another example of the exhaust duct. FIG. 16 is a side view illustrating another example of the exhaust duct.

  Exemplary embodiments of an exhaust duct and a boiler according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, and when there are two or more embodiments, what comprises combining each embodiment is also included.

  FIG. 1 is a schematic configuration diagram illustrating a pulverized coal fired boiler to which an exhaust duct according to the present embodiment is applied.

  The pulverized coal burning boiler 10 to which the exhaust duct of the present embodiment is applied uses pulverized coal obtained by pulverizing coal as a solid fuel, burns the pulverized coal with a combustion burner 21, and recovers heat generated by the combustion. This is a possible boiler. Here, the description will be made by applying the pulverized coal burning boiler 10, but the present invention is not limited to this type of boiler, and the fuel is not limited to coal.

  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 five 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 portion thereof, and superheaters (superheaters) 41 and 42 for recovering heat of the exhaust gas G as a convection heat transfer part (heat recovery part). Reheaters (reheaters) 43 and 44 and economizers 45, 46 and 47 are provided, and heat exchange is performed between the exhaust gas G 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 G 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 G flowing through the exhaust gas pipe 48, and the combustion burners 21, 22, 23. , 24, 25 can raise the temperature of combustion air.

  Further, in the exhaust gas pipe 48, a selective reduction type catalyst 50 is provided at a position upstream of the air heater 49, and a dust treatment device (electric dust collector, desulfurization device) 51 and an induction blower 52 are provided at a position downstream of the air heater 49. A chimney 53 is provided at the downstream end. Here, the selective catalytic reduction catalyst 50 and the dust treatment device 51 function as a harmful substance removal 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 G) rises in the furnace 11 and smoke It is discharged to the road 40.

  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 G that has passed through the economizers 45, 46, and 47 of the flue 40 is removed of harmful substances such as NOx by the selective reduction catalyst 50 in the exhaust gas pipe 48, and the particulate matter is processed by the dust treatment device 51. Is removed and the sulfur content is removed, and then discharged from the chimney 53 to the atmosphere.

  In the pulverized coal burning boiler 10 configured in this way, the flue 40 on the downstream side from the furnace 11 functions as an exhaust duct of the present embodiment. The flue 40 includes a first horizontal flue portion (first vertical portion) 40a, a first vertical flue portion 40b, a second horizontal flue portion (horizontal portion) 40c, and a second vertical flue portion (first 2 vertical portions) 40d, a third horizontal flue portion 40e, a third vertical flue portion 40f, and a fourth horizontal flue portion 40g are continuously provided. In addition, the kicker 54 along a horizontal direction is provided inside the connection part of the 1st vertical flue part 40b and the 2nd horizontal flue part 40c.

  And in the flue 40, the superheaters 41 and 42, the reheaters 43 and 44, and the economizers 45, 46, and 47 are arrange | positioned at the 1st horizontal flue part 40a and the 1st vertical flue part 40b. . The flue 40 has a first hopper 61 at the lower end of the first vertical flue portion 40b through which the exhaust gas G having a downward speed component flows, and the second vertical smoke through which the exhaust gas G having an upward speed component flows. A second hopper 65 is installed at the lower end of the road portion 40d. Further, in the flue 40, the selective reduction catalyst 50 is installed in the third vertical flue portion 40f through which the exhaust gas G flows downward.

  Hereinafter, the exhaust duct of the present embodiment will be described in detail. FIG. 2 is a side view showing the exhaust duct according to the present embodiment. 3 and 4 are perspective views showing a low repulsion part in the exhaust duct. 5 and 6 are schematic views showing the action of the low repulsion part. 7 to 14 are diagrams showing the tension applying portion in the exhaust duct.

  As shown in FIG. 2, the exhaust duct of the present embodiment includes an exhaust gas passage 60 that flows the exhaust gas G, a first hopper 61 that is provided in the exhaust gas passage 60 and collects solid particles in the exhaust gas G, and a first hopper. A low repulsion portion 62 (FIGS. 3 and 4) provided along the inner wall surface of the exhaust gas passage 60 on the upstream side in the flow direction of the exhaust gas G with respect to 61 and having a smaller restitution coefficient than the inner wall surface, and a low repulsion portion A tension applying unit 63 (see FIGS. 7 to 14) for applying tension.

  The exhaust gas passage 60 includes a first vertical flue portion 40b in which the exhaust gas G flows downward in the vertical direction, and a second horizontal flue portion 40c that is connected to the first vertical flue portion 40b and in which the exhaust gas G flows in the horizontal direction. Have. In the exhaust gas passage 60, a first hopper 61 is provided at a lower portion of a connection portion between the first vertical flue portion 40b and the second horizontal flue portion 40c. Further, in the exhaust gas passage 60, the first vertical flue portion 40b is provided with a lower wall surface portion 71 at the lower portion. The lower wall surface portion 71 is an inclined surface that is inclined downward at a predetermined angle toward the second horizontal flue portion 40c and the first hopper 61 side. In the exhaust gas passage 60, the second horizontal flue portion 40c is provided with a lower wall surface portion 72 at the lower portion. The lower wall surface 72 is a horizontal plane along the horizontal direction.

  The first hopper 61 mainly collects and stores large-diameter ash popcorn ash (hereinafter referred to as PA) as solid particles contained in the exhaust gas G. The first hopper 61 has a first inclined surface 73 and a second inclined surface 74 whose inner wall faces in the flow direction of the exhaust gas G so that the area becomes narrower downward, and each inclined surface 73, 74. The storage part 75 is provided in the bottom position where the lower end part is connected. In the first hopper 61, an opening that can be opened and closed by an opening / closing valve (not shown) is provided in the reservoir 75, and the stored PA can be discharged downward by opening the opening.

  Here, the lower wall surface portion 71 of the first vertical flue portion 40b and the first inclined surface 73 of the first hopper 61 are connected to form a continuous surface at substantially the same inclination angle. The angles of the lower wall surface 71 and the first inclined surface 73 are set so as to be equal to or greater than the repose angle at which PA falls. Moreover, the 2nd inclined surface 74 of the 1st hopper 61 and the 2nd horizontal flue part 40c are connected so that it may bend at a predetermined angle.

  The low repulsion part 62 is provided on the upstream side in the flow direction of the exhaust gas G with respect to the first hopper 61 and along the lower wall part 71 that is the inner wall surface of the first vertical flue part 40b. Since the lower wall surface portion 71 of the first vertical flue portion 40b is an inclined surface, the low repulsion portion 62 has a low repulsion portion inclined surface 62a whose surface follows the inclination of the lower wall surface portion 71. The angle is substantially the same as that of the inclined surface 73. The low repulsion part 62 has a sheet shape having a predetermined area, is fixed to a lower wall surface part (inclined surface) 71 in the first vertical flue part 40b, and the collection rate of PA in the first hopper 61 In order to improve this effectively, it is comprised by the member whose restitution coefficient is smaller than the material (for example, iron plate) which makes the lower wall part 71. FIG. Therefore, when PA falls along the low repulsion part 62, PA falls while contacting the low repulsion part inclined surface 62a, so that the amount of repulsion when colliding with the low repulsion part 62 is suppressed.

  As a result, the PA that has fallen together with the downward exhaust gas G directly collides with the low repulsion part 62, and therefore rebounds lower than the amount of repulsion when directly colliding with the lower wall surface part 71 that is an iron plate. The probability of jumping over the first hopper 61 and scattering to the lower wall surface portion 72 of the second horizontal flue portion 40c is reduced, and the PA collection rate in the first hopper 61 is improved.

  As shown in FIG. 3, the low repulsion part 62 includes a metal net 81 as a low repulsion part forming member and a pair of frames 82 that support both ends (lateral direction) of the metal net 81. The metal mesh 81 is arranged with a predetermined height floating with respect to the lower wall surface portion (inclined surface) 71 of the iron plate duct by the pair of frame bodies 82, so that the space between the lower wall surface portion (inclined surface) 71 and the wire mesh is set. Thus, a space 83 is secured. The wire net 81 is provided with a large number of openings 84 serving as PA passages.

  Moreover, the low repulsion part 62 is comprised from the metal mesh 81 as a low repulsion part formation member and a pair of frame 85 which supports the both ends of the up-down direction of this metal net 81, as shown in FIG. The metal mesh 81 is disposed so as to float by a predetermined height with respect to the lower wall surface portion (inclined surface) 71 of the iron plate duct by a pair of frame bodies 85, so that the space between the lower wall surface portion (inclined surface) 71 and the wire mesh is set. Thus, a space 83 is secured. The wire net 81 is provided with a large number of openings 84 serving as PA passages. The frame body 85 is formed in a gate shape so as to open in the vertical direction along the lower wall surface portion (inclined surface) 71, so that the space portion 83 is formed between the lower wall surface portion (inclined surface) 71 and the wire mesh. It is open vertically.

  According to the low repulsion part 62 shown in FIGS. 3 and 4, as shown in FIG. 5, the PA falling downward in the vertical direction passes through the opening 84 of the wire mesh 81 and lower wall part (inclined surface) 71. However, there is a high probability that it will collide with the back side of the wire net 81 again. As a result, the PA that has collided with the rear surface side of the wire mesh 81 falls along the lower wall surface portion (inclined surface) 71 and falls into the first hopper 61 finally.

  On the other hand, according to the low repulsion part 62 shown in FIG. 3 and FIG. 4, not all of the PA that falls downward in the vertical direction passes through the opening 84 of the wire mesh 81. As shown in FIG. Some of them collide with a wire mesh 81 in which a plurality of members are combined in a lattice shape. The PA that collides with the wire member of the wire mesh 81 collides with a member that has a lower coefficient of restitution than a normal steel plate and is easily elastically deformed. As a result, the probability of being recovered by the first hopper 61 due to the decrease in the amount of restitution is high. Become. Thus, the low repulsion part 62 can efficiently collect the PA that has passed through the opening 84 of the wire mesh 81 and the PA that has collided with the wire mesh 81 into the first hopper 61, so that the collection rate of PA in the first hopper 61 is improved. It is effective for.

  On the other hand, according to the low repulsion part 62 shown in FIGS. 3 and 4, the PA that has entered the space 83 of the metal mesh 81 from above is a space along the lower wall surface part (inclined surface) 71, although not clearly shown in the drawings. The part 83 is dropped and finally collected by the first hopper 61. Therefore, in order to obtain such an action, the frame body 85 is formed in a gate shape.

  In the present embodiment, the low repulsion portion forming member of the low repulsion portion 62 is the wire net 81, but is not limited to this configuration. As the low repulsion part, in addition to the wire mesh 81, for example, a wire in which linear members are bundled and arranged in a line at a predetermined interval, or a large structure through which the PA can pass, such as a saddle structure (an armor door), etc. Those having a large number of openings 84 can be used. In particular, if a lattice-like low-repulsion member made of a material that elastically deforms in response to a collision with a PA, such as a linear member, is employed, the collision energy of the PA can be efficiently absorbed by the elastic deformation to reduce the amount of repulsion. Is possible. In addition, the amount of repulsion can be reduced by rotating the collided PA. The low repulsion part 62 can also employ a heat insulating material, a rubber material, a plastic material, or the like.

  The tension applying unit 63 is roughly divided in the present embodiment, and is shown in the form shown in FIGS. 7 and 8, the form shown in FIGS. 9 and 10, the form shown in FIGS. 11 and 12, and the form shown in FIGS. There is a form.

  7 and 8 includes a supporting portion 91 fixed to a lower wall surface portion (inclined surface) 71 that is an inner wall surface of the exhaust gas passage 60, and a lower wall surface portion 71 with respect to the supporting portion 91. And a fixing portion 92 provided so as to be fixable at an arbitrary position close to or away from the head.

  The support portion 91 is formed in a rod shape having one end fixed to the lower wall surface portion 71 and the other end extending in a direction away from the lower wall surface portion 71. The support portion 91 is provided between the frame body 82 (or the frame body 85) of the low repulsion portion 62 and is inserted through the opening 84 of the wire mesh 81. Moreover, the support part 91 may be provided with two or more between the frame bodies 82 (or frame body 85).

  The fixing portion 92 is provided so as to be movable along the extending direction of the support portion 91 and to be fixed at an arbitrary position. For example, since the support portion 91 is configured as a male screw and the fixing portion 92 is configured as a nut, the fixing portion 92 can be moved along the extending direction of the supporting portion 91 and fixed at an arbitrary position. It becomes possible. Further, even if the rod-shaped support portion 91 is inserted into the fixed portion 92 and the support portion 91 is sandwiched between the fixed portions 92, the fixed portion 92 can be moved along the extending direction of the support portion 91 and can be arbitrarily It can be fixed at the position.

  Then, a part of the wire mesh 81 is moved relative to the support portion 91 together with the fixed portion 92. In FIG. 7, a part of the wire net 81 is moved to the side away from the lower wall surface portion 71 together with the fixing portion 92. Further, in FIG. 8, a part of the wire mesh 81 is moved to the side close to the lower wall surface portion 71 together with the fixing portion 92. Thereby, in the wire mesh 81 whose both ends are supported on the lower wall surface portion 71 side by the frame body 82 (or the frame body 85), a part between the both ends moves with respect to the lower wall surface portion 71 by the fixing portion 92. Thus, tension is applied to the wire mesh 81.

  9 and 10 includes an elastic member 93, one end of which is fixed to a lower wall surface (inclined surface) 71 that is an inner wall surface of the exhaust gas passage 60, and a wire mesh 81 is attached to the other end. It has been.

  The elastic member 93 is configured as a coil spring, for example. In FIG. 9, the elastic member 93 is configured as a compression coil spring, and a part of the metal mesh 81 is pressed to the side away from the lower wall surface portion 71 by the elastic force. In FIG. 10, the elastic member 93 is configured as a tension coil spring, and a part of the metal mesh 81 is pulled toward the side close to the lower wall surface portion 71 by the elastic force. Thereby, in the wire mesh 81 in which both ends are supported on the lower wall surface portion 71 side by the frame body 82 (or the frame body 85), a part between the both ends is urged by the elastic force of the elastic member 93. Tension is applied to the wire mesh 81.

  The tension applying unit 63 in the form shown in FIGS. 11 and 12 includes an expansion member 94. The expansion member 94 is made of a material having a linear expansion coefficient equal to or greater than that of the wire mesh 81. The expansion member 94 is provided along the lower wall surface portion (inclined surface) 71 that is the inner wall surface of the exhaust gas passage 60 together with the metal mesh 81 on the lower wall surface portion 71 side of the metal mesh 81, and both ends of the metal mesh 81 are framed. It is attached via a body 85 (or frame body 82). The expansion member 94 is separated from the lower wall surface portion 71 with the frame body 85 (or the frame body 82) on one end side of the wire mesh 81 attached to the lower wall surface portion 71 and the other end side as a free end. And cantilevered. As will be described later, the lower wall surface portion 71 is an inclined surface, and it is suitable for being arranged in a cantilevered manner on this inclined surface if it is arranged in a form suspended from the upper side by a gate-shaped frame body 85. It is preferable when the mounting state is stabilized. However, the configuration in which the frame 82 is attached from the side by holding is not excluded. In addition, the expansion member 94 is formed in a rod shape, and is spanned between a plurality of frames 85 (or both frame bodies 82) at a plurality of locations (in this embodiment, three locations on both sides and the center).

  The expansion member 94 is expanded by the exhaust gas G passing through the exhaust gas pipe (exhaust gas passage) 48. Thereby, tension is applied to the wire mesh 81.

  The tension applying unit 63 in the form shown in FIGS. 13 and 14 includes a weight 95. The weight 95 is attached to the lower end of a metal mesh 81 whose upper end is attached to a lower wall surface portion (inclined surface) 71 that is an inner wall surface of the exhaust gas passage 60 with a frame body 85. The weights 95 are provided at a plurality of locations (two locations on both sides in the present embodiment) with respect to the lower end of the wire mesh 81. Further, the weight 95 has a predetermined height from the lower wall surface portion 71 and is attached to the lower end of the wire net 81 so that the space portion 83 can be formed when the weight 95 comes into contact with the lower wall surface portion 71. In addition, when the lower end of the metal net 81 bends unstablely, it is preferable to arrange the reinforcing member 86 along the lower end of the metal net 81 in order to compensate for this and eliminate the bending. Further, the weight 95 is formed so as to become gradually thinner toward the upper end attached to the lower end of the wire net 81, and is configured to easily fall without retaining the PA.

  The weight 95 applies a downward load to the wire net 81 by its own weight. Thereby, tension is applied to the wire mesh 81.

  Here, the effect | action of the exhaust duct of this embodiment is demonstrated.

  As shown in FIG. 1, after the heat of the exhaust gas G is recovered by the heat recovery section (superheaters 41 and 42, reheaters 43 and 44, and economizers 45, 46 and 47) of the flue 40, The first vertical flue portion 40b is lowered, bent substantially at a right angle, and flows into the second horizontal flue portion 40c. At this time, the exhaust gas G is stored after the contained PA freely falls in the first hopper 61.

  When the exhaust gas G flows from the first vertical flue portion 40b into the second horizontal flue portion 40c, the PA receives kinetic energy from the exhaust gas G, and the lower wall surface portion (inclined at a predetermined speed by inertial force (centrifugal force). Surface) 71 and the first hopper 61 side. At this time, the PA that falls downward collides with the low repulsion part 62 and the repulsion force is reduced, and rolls on the low repulsion part inclined surface 62 a of the low repulsion part 62 and is collected by the first hopper 61.

  Here, since the low repulsion part 62 expand | swells with the high temperature exhaust gas G, the metal mesh 81 loosens and a repulsive force falls. The exhaust duct of the present embodiment always maintains the repulsive force of the low repulsion part 62 because the tension is applied to the low repulsion part 62 by the tension applying part 63.

  As described above, in the exhaust duct of the present embodiment, the exhaust gas passage 60 through which the exhaust gas G flows, the first hopper 61 provided in the exhaust gas passage 60 to collect PA in the exhaust gas G, and the first hopper 61 On the other hand, a low repulsion portion 62 provided along the inner wall surface of the exhaust gas passage 60 on the upstream side in the flow direction of the exhaust gas G and having a smaller coefficient of restitution than the inner wall surface, and a tension applying portion 63 that applies tension to the low repulsion portion 62. And having.

  Therefore, when the exhaust gas G flows through the exhaust gas passage 60, PA is separated from the exhaust gas G and collected by the first hopper 61. At this time, since PA has inertial force, it collides with the inner wall surface of the exhaust gas passage 60 and tends to flow out downstream without being collected by the first hopper 61, but this PA collides with the low repulsion part 62. For this reason, the amount of repulsion decreases and is appropriately collected by the first hopper 61. Moreover, although the low repulsion part 62 expand | swells with the high temperature exhaust gas G, since tension | tensile_strength is provided by the tension | tensile_strength provision part 63, a repulsive force is always maintained. As a result, the PA in the exhaust gas G can be properly collected in the first hopper 61, and the collection efficiency can be improved.

  Further, in the exhaust duct of the present embodiment, the tension applying portion 63 can be fixed to the support portion 91 fixed to the inner wall surface of the exhaust gas passage 60 and any position close to or separated from the inner wall surface with respect to the support portion 91. A low-repulsion part 62 is supported on the inner wall surface, and a part of the low-repulsion part 62 between both ends is moved together with the fixing part 92 from the inner wall surface. Tension is applied to the repulsion unit 62.

  Further, in the exhaust duct of the present embodiment, the tension applying portion 63 is made of an elastic member 93, supports both ends of the low repulsion portion 62 on the inner wall surface side, and elastically applies a part of the low repulsion portion 62 between both ends. By applying the force, the tension is applied to the low repulsion part.

  Further, in the exhaust duct of the present embodiment, the tension applying unit 63 includes an expansion member 94 having a linear expansion coefficient equal to or greater than that of the low repulsion unit 62, and the expansion member 94 together with the low repulsion unit 62 is an exhaust gas passage. One end side of both ends of the low repulsion part 62 attached to the inner wall surface 60 is fixed to the inner wall surface, and the other end side is arranged as a free end, and tension is applied to the low repulsion part 62 by expansion. Give.

  Further, in the exhaust duct of the present embodiment, the tension applying portion 63 includes a weight 95, is attached to the lower end of the low repulsion portion 62 whose upper end is fixed to the inner wall surface of the exhaust gas passage 60, and is attached to the low repulsion portion 62 by its own weight. Apply tension.

  Therefore, the low repulsion part 62 is applied with tension by the tension applying parts 63 having various configurations as described above, and the repulsive force is always maintained. As a result, the PA in the exhaust gas G can be properly collected in the first hopper 61, and the collection efficiency can be improved.

  In the exhaust duct of the present embodiment, as the exhaust gas passage 60, a first vertical flue portion 40b in which the exhaust gas G flows downward in the vertical direction and a second horizontal flue portion connected to the first vertical flue portion 40b. 40c, the first hopper 61 is provided at the lower part of the connecting portion between the first vertical flue portion 40b and the second horizontal flue portion 40c, and the low repulsion portion 62 and the tension applying portion 63 are provided with respect to the first hopper 61. And provided on the lower wall surface portion 71 in the first vertical flue portion 40b on the upstream side in the flow direction of the exhaust gas G.

  Therefore, when the low repulsion part 62 is provided on the upstream side of the first hopper 61, the PA contained in the exhaust gas G collides with the low repulsion part 62 before the first hopper 61, and the inertia force is reduced here. As a result, the first hopper 61 can be easily entered, so that the amount of PA that jumps over the first hopper 61 to the downstream side and flows out can be reduced.

  Further, in the exhaust duct of the present embodiment, the low repulsion portion 62 is provided with a low repulsion portion inclined surface 62 a that is inclined in the same direction as the first inclined surface 73 of the first hopper 61.

  Therefore, when the PA contained in the exhaust gas G collides with the low repulsion part 62, the PA falls from the low repulsion part inclined surface 62a of the low repulsion part 62 along the first inclined surface 73 of the first hopper 61, and the first It will be collected by the hopper 61 and the PA can be properly guided to the first hopper 61.

  Although not clearly shown in the figure, the low repulsion part 62 may also be provided on the first inclined surface 73 and the second inclined surface 74 which are the inner wall surfaces of the first hopper 61.

  Therefore, since the low repulsion part 62 is also provided on the first inclined surface 73 and the second inclined surface 74 which are the inner wall surfaces of the first hopper 61, the low repulsion part 62 appropriately reduces the inertial force of the solid particles. This makes it easy to enter the first hopper 61 and suppresses re-scattering of the solid particles from the first hopper 61.

  FIG. 15 is a side view illustrating another example of the exhaust duct.

  As shown in FIG. 15, the exhaust duct includes an exhaust gas passage 60 that flows exhaust gas, a first hopper 61 that is provided in the exhaust gas passage 60 and collects solid particles in the exhaust gas, and an exhaust gas G with respect to the first hopper 61. A low repulsion portion 102 that is provided along the inner wall surface of the exhaust gas passage 60 on the upstream side in the flow direction and has a smaller coefficient of restitution than the inner wall surface, and a tension applying portion 63 that applies tension to the low repulsion portion 102. .

  The first hopper 61 mainly collects and stores PA of large-diameter ash contained in the exhaust gas G. The first hopper 61 has a first inclined surface 73 and a second inclined surface 74 whose inner wall faces in the flow direction of the exhaust gas G so that the area becomes narrower downward, and each inclined surface 73, 74. The storage part 75 is provided in the bottom position where the lower end part is connected.

  The low repulsion part 102 is provided on the upstream side in the flow direction of the exhaust gas G with respect to the first hopper 61, and is provided from the lower wall surface part 71 in the first vertical flue part 40 b to the first inclined surface 73 of the first hopper 61. It has been. Since the first inclined surface 73 of the first hopper 61 from the lower wall surface portion 71 of the first vertical flue portion 40b is an inclined surface, the surface of the low repulsion portion 102 is the inclination of the lower wall surface portion 71 and the first inclination. It is a low repulsion portion inclined surface 102 a along the inclination of the surface 73, and has substantially the same angle as the lower wall surface portion 71 and the first inclined surface 73. The low repulsion part 102 has a sheet shape having a predetermined area, and the first low repulsion part 103 fixed to the lower wall surface part (inclined surface) 71 in the first vertical flue part 40 b and the first hopper 61 The second low repulsion part 104 is fixed to the first inclined surface 73. In order to effectively improve the collection rate of PA in the first hopper 61, the low repulsion part 102 is configured by a member having a restitution coefficient smaller than that of the material forming the lower wall surface part 71 (for example, an iron plate). The low repulsion unit 102 includes a first low repulsion unit 103 and a second low repulsion unit 104, and is configured in the same manner as the low repulsion unit 62 shown in FIGS.

  The tension applying unit 63 replaces the low-repulsion unit 62 described above with the low-repulsion unit 102, forms shown in FIGS. 7 and 8, forms shown in FIGS. 9 and 10, and forms shown in FIGS. There is a form shown in FIGS.

  Thus, in the exhaust duct of the present embodiment, the low repulsion portion inclined surface 102a of the low repulsion portion 102 extends from the lower wall surface portion 71 in the first vertical flue portion 40b to the first inclined surface 73 of the first hopper 61. It extends to.

  Therefore, when the exhaust gas G flows through the exhaust gas passage 60, PA is separated from the exhaust gas G and collected by the first hopper 61. At this time, since PA has inertial force, it collides with the inner wall surface of the exhaust gas passage 60 and is not collected by the first hopper 61 and tends to flow out to the downstream side. 1 Since it collides with the low repulsion part 103, the amount of repulsion falls here and it is collect | recovered by the 1st hopper 61 appropriately. Further, the PA that has directly dropped onto the first hopper 61 has its repulsive force reduced by the second low repulsion portion 104 on the first inclined surface 73 side, and re-scattering from the first hopper 61 is prevented. Moreover, although the low repulsion part 102 expand | swells with the high temperature exhaust gas G, since tension | tensile_strength is provided by the tension | tensile_strength provision part 63, a repulsive force is always maintained. As a result, the PA in the exhaust gas G can be properly collected in the first hopper 61, and the collection efficiency can be improved.

  Although not clearly shown in the figure, the low repulsion part 102 may also be provided on the first inclined surface 73 and the second inclined surface 74 which are the inner wall surfaces of the first hopper 61.

  Accordingly, since the low repulsion part 102 is also provided on the first inclined surface 73 and the second inclined surface 74 which are the inner wall surfaces of the first hopper 61, the low repulsion part 62 appropriately reduces the inertial force of the solid particles. This makes it easy to enter the first hopper 61 and suppresses re-scattering of the solid particles from the first hopper 61.

  FIG. 16 is a side view illustrating another example of the exhaust duct.

  As shown in FIG. 16, the exhaust duct includes an exhaust gas passage 60 that flows the exhaust gas G, a second hopper 65 that is provided in the exhaust gas passage 60 and collects solid particles in the exhaust gas, and an exhaust gas with respect to the second hopper 65. A low repulsion portion 112 provided along the inner wall surface of the exhaust gas passage 60 and having a smaller coefficient of restitution than the inner wall surface, and a tension applying portion 63 that applies tension to the low repulsion portion 112. Have.

  The exhaust gas passage 60 includes a second horizontal flue portion 40c through which the exhaust gas flows in the horizontal direction, and a second vertical flue portion 40d that is connected to the second horizontal flue portion 40c and through which the exhaust gas flows upward in the vertical direction. The second hopper 65 is provided at the lower part of the connecting portion between the second horizontal flue portion 40c and the second vertical flue portion 40d. The second horizontal flue portion 40c is provided with a lower wall surface portion 72 at the lower portion, and the lower wall surface portion 72 is a horizontal plane along the horizontal direction. The second vertical flue portion 40d is on the downstream side in the flow direction of the exhaust gas with respect to the second hopper 65 (upper side in the vertical direction in FIG. 16), and the vertical wall surface at a position where the lower wall surface portion 72 is orthogonal. A portion 78 is provided, and the standing wall surface portion 78 is a vertical surface.

  The second hopper 65 mainly collects and stores PA of large-diameter ash contained in the exhaust gas G. The second hopper 65 has a first inclined surface 121 and a second inclined surface 122 whose inner wall surfaces oppose each other in the flow direction of the exhaust gas G so that the area becomes narrower downward. The storage part 123 is provided in the bottom position to which the lower end part is connected. In the second hopper 65, an opening that can be opened and closed by an opening / closing valve (not shown) is provided in the reservoir 123, and the stored PA can be discharged downward by opening the opening. Here, the lower wall surface 72 of the second horizontal flue portion 40c and the first inclined surface 121 of the second hopper 65 are connected, and the standing wall surface 78 of the second vertical flue portion 40d and the second hopper 65 second. The inclined surface 122 is connected.

  The low repulsion part 112 is provided downstream of the second hopper 65 in the flow direction of the exhaust gas G, and is provided on the standing wall surface part 78 in the second vertical flue part 40d. Since the standing wall surface portion 78 of the second vertical flue portion 40d is a vertical surface, the surface of the low repulsion portion 112 is a low repulsion portion vertical surface 112a. The low repulsion portion 112 has a sheet shape having a predetermined area and is made of a material (for example, an iron plate) forming the standing wall portion 78 in order to effectively improve the collection rate of PA in the second hopper 65. It is composed of a member having a small coefficient of restitution. Therefore, the amount of repulsion when PA collides with the low repulsion part 112 is suppressed. As a result, the PA that has moved together with the flowing exhaust gas G in the horizontal direction directly collides with the low repulsion portion 112, and therefore rebounds lower than the rebound amount when directly colliding with the standing wall surface portion 78 that is an iron plate. The PA collection rate in the second hopper 65 is improved. Moreover, the low repulsion part 112 is comprised similarly to the low repulsion part 62 shown in FIGS.

  The tension applying unit 63 replaces the low-repulsion unit 62 described above with the low-repulsion unit 112, forms shown in FIGS. 7 and 8, forms shown in FIGS. 9 and 10, and forms shown in FIGS. There is a form shown in FIGS.

  Therefore, when the exhaust gas G flows from the second horizontal flue portion 40c into the second vertical flue portion 40d, the PA receives kinetic energy from the exhaust gas G, and the vertical wall surface portion at a predetermined speed by inertial force (centrifugal force). Move to 78 side. At this time, PA collides with the low repulsion part 112 and the repulsion force is reduced, and after colliding with the low repulsion part 112, it falls to the second hopper 65 and is collected.

  As described above, in the exhaust duct of the present embodiment, the exhaust gas passage 60 through which the exhaust gas flows, the second hopper 65 provided in the exhaust gas passage 60 to recover PA in the exhaust gas G, and the second hopper 65 A low repulsion portion 112 provided along the inner wall surface of the exhaust gas passage 60 and having a smaller coefficient of restitution than the inner wall surface, and a tension applying portion that applies tension to the low repulsion portion 112. 63.

  Accordingly, when the exhaust gas G flows through the exhaust gas passage 60, PA is separated from the exhaust gas G and collected by the second hopper 65. At this time, since PA has inertial force, it collides with the inner wall surface of the exhaust gas passage 60 and is likely not to be collected by the second hopper 65 but scattered around, but this PA collides with the low repulsion part 112. Therefore, the amount of repulsion decreases here and is appropriately recovered by the second hopper 65. Moreover, although the low repulsion part 112 expand | swells with the high temperature waste gas G, since tension | tensile_strength is provided by the tension | tensile_strength provision part 63, a repulsive force is always maintained. As a result, the PA in the exhaust gas G can be properly collected in the second hopper 65, and the collection efficiency can be improved.

  Although not clearly shown in the figure, the low repulsion part 112 may also be provided on the first inclined surface 121 or the second inclined surface 122 which is the inner wall surface of the second hopper 65.

  Therefore, since the low repulsion part 112 is also provided on the first inclined surface 121 and the second inclined surface 122 which are the inner wall surfaces of the second hopper 65, the low repulsion part 112 appropriately reduces the inertial force of the solid particles. Thus, the second hopper 65 can be easily entered, and re-scattering of the solid particles from the second hopper 65 can be suppressed.

  Further, in the boiler of the present embodiment, a furnace 11 that is hollow and installed along the vertical direction, a combustion apparatus 12 that blows fuel gas into the furnace 11 and burns it, and a furnace 11 An exhaust duct connected to the downstream side in the flow direction of the exhaust gas G, and a heat recovery unit (superheaters 41 and 42, reheaters 43 and 44, and coal-saving) provided in the exhaust duct and capable of recovering heat in the exhaust gas G 45, 46, 47).

  Therefore, a flame is formed by injecting fuel gas into the furnace 11 by the combustion device 12, the generated combustion gas flows into the exhaust duct, and the heat recovery part recovers the heat in the exhaust gas, while the PA is separated from the exhaust gas G. Then, it is collected by the first hopper 61 and the second hopper 65. At this time, since the PA collides with the low repulsion part 62, the low repulsion part 102, and the low repulsion part 112, the amount of repulsion decreases here and is appropriately collected by the first hopper 61. Moreover, the low repulsion part 62, the low repulsion part 102, and the low repulsion part 112 expand | swell by the high temperature exhaust gas G, but since the tension | tensile_strength is provided by the tension | tensile_strength provision part 63, a repulsive force is always maintained. As a result, the PA in the exhaust gas G can be properly collected in the first hopper 61 and the second hopper 65, and the collection efficiency can be improved.

  In the above-described embodiment, the exhaust duct is applied to a pulverized coal fired boiler. However, the present invention is not limited to this type of boiler. Moreover, you may apply not only to a boiler but to any exhaust duct, as long as it flows the exhaust gas containing solid particles.

DESCRIPTION OF SYMBOLS 10 Pulverized coal fired boiler 11 Furnace 21, 22, 23, 24, 25 Combustion burner 40 Flue 40b 1st vertical flue part (1st vertical part)
40c Second horizontal flue section (horizontal section)
40d Second vertical flue section 41, 42 Superheater (heat recovery section)
43, 44 Reheater (Heat recovery part)
45, 46, 47 Energy-saving equipment (heat recovery part)
60 exhaust gas passage 61 first hopper 62, 102, 112 low repulsion part 63 tension applying part 65 second hopper 71, 72 lower wall surface part 78 standing wall surface part G exhaust gas PA popcorn ash (solid particles)

Claims (12)

An exhaust gas passage through which exhaust gas flows;
A hopper provided in the exhaust gas passage for recovering solid particles in the exhaust gas;
A low repulsion portion provided along the inner wall surface of the exhaust gas passage on the upstream side or the downstream side in the flow direction of the exhaust gas with respect to the hopper and having a smaller coefficient of restitution than the inner wall surface;
A tension applying unit that applies tension to the low repulsion unit;
I have a,
The exhaust gas passage has a first vertical part in which exhaust gas flows downward in the vertical direction, and a horizontal part connected to the first vertical part, and the hopper includes the first vertical part and the horizontal part. The low repulsion part and the tension applying part are provided in a lower part of a connecting part, and are provided on a lower wall surface part in the first vertical part on the upstream side in the flow direction of exhaust gas with respect to the hopper. And exhaust duct. The exhaust duct according to claim 1 , wherein the low repulsion part has a low repulsion part inclined surface inclined in the same direction as the inclined surface of the hopper. An exhaust gas passage through which exhaust gas flows;
A hopper provided in the exhaust gas passage for recovering solid particles in the exhaust gas;
A low repulsion portion provided along the inner wall surface of the exhaust gas passage on the upstream side or the downstream side in the flow direction of the exhaust gas with respect to the hopper and having a smaller coefficient of restitution than the inner wall surface;
A tension applying unit that applies tension to the low repulsion unit;
I have a,
The exhaust gas passage has a horizontal part in which exhaust gas flows in a horizontal direction and a second vertical part connected to the horizontal part and in which exhaust gas flows upward in the vertical direction, and the hopper includes the horizontal part and the second vertical part. The low repulsion part and the tension applying part are provided on the downstream side in the exhaust gas flow direction with respect to the hopper, and the second vertical part is opposed to the horizontal part. An exhaust duct provided on a vertical wall surface .   The said tension | tensile_strength provision part consists of weights, it is attached to the lower end of the said low repulsion part by which the upper end was fixed to the said inner wall surface, and tension | tensile_strength is given to the said low repulsion part by dead weight. Item 4. The exhaust duct according to any one of Items 3 to 4. An exhaust gas passage through which exhaust gas flows;
A hopper provided in the exhaust gas passage for recovering solid particles in the exhaust gas;
A low repulsion portion provided along the inner wall surface of the exhaust gas passage on the upstream side or the downstream side in the flow direction of the exhaust gas with respect to the hopper and having a smaller coefficient of restitution than the inner wall surface;
A tension applying unit that applies tension to the low repulsion unit;
Have
The tension applying unit includes a support unit fixed to the inner wall surface, and a fixing unit provided so as to be fixed at an arbitrary position close to or separated from the inner wall surface with respect to the support unit. Supporting both ends of the repulsion portion on the inner wall surface side, and applying a tension to the low repulsion portion by moving a part of the low repulsion portion between the both ends together with the fixing portion from the inner wall surface. exhaust duct shall be the. An exhaust gas passage through which exhaust gas flows;
A hopper provided in the exhaust gas passage for recovering solid particles in the exhaust gas;
A low repulsion portion provided along the inner wall surface of the exhaust gas passage on the upstream side or the downstream side in the flow direction of the exhaust gas with respect to the hopper and having a smaller coefficient of restitution than the inner wall surface;
A tension applying unit that applies tension to the low repulsion unit;
Have
The tension applying portion is made of an elastic member, supports both ends of the low repulsion portion on the inner wall surface side, and biases a part of the low repulsion portion between both ends by an elastic force to the low repulsion portion. exhaust duct shall be the features that you grant the tension. An exhaust gas passage through which exhaust gas flows;
A hopper provided in the exhaust gas passage for recovering solid particles in the exhaust gas;
A low repulsion portion provided along the inner wall surface of the exhaust gas passage on the upstream side or the downstream side in the flow direction of the exhaust gas with respect to the hopper and having a smaller coefficient of restitution than the inner wall surface;
A tension applying unit that applies tension to the low repulsion unit;
Have
The tension applying portion is composed of an expansion member having a linear expansion coefficient equal to or greater than that of the low repulsion portion, and the expansion member is provided along the inner wall surface together with the low repulsion portion, and the low repulsion portion one end of both ends of the parts are attached is fixed to the inner wall surface, the other end is disposed as a free end, exhaust duct you wherein applying tension to said foam portion by the expansion. The exhaust gas passage has a first vertical part in which exhaust gas flows downward in the vertical direction, and a horizontal part connected to the first vertical part, and the hopper includes the first vertical part and the horizontal part. The low repulsion part and the tension applying part are provided in a lower part of a connecting part, and are provided on a lower wall surface part in the first vertical part on the upstream side in the flow direction of exhaust gas with respect to the hopper. The exhaust duct according to any one of claims 5 to 7 . The exhaust duct according to claim 8 , wherein the low repulsion part has a low repulsion part inclined surface inclined in the same direction as the inclined surface of the hopper. The exhaust gas passage has a horizontal part in which exhaust gas flows in a horizontal direction and a second vertical part connected to the horizontal part and in which exhaust gas flows upward in the vertical direction, and the hopper includes the horizontal part and the second vertical part. The low repulsion part and the tension applying part are provided on the downstream side in the exhaust gas flow direction with respect to the hopper, and the second vertical part is opposed to the horizontal part. The exhaust duct according to any one of claims 5 to 7 , wherein the exhaust duct is provided on a standing wall surface portion. The exhaust duct according to any one of claims 1 to 10 , wherein the low repulsion part is also provided on an inner wall surface of the hopper. A furnace that is hollow and installed along the vertical direction;
A combustion apparatus for injecting fuel into the furnace and burning it;
The exhaust duct according to any one of claims 1 to 11 , connected to the downstream side of the flow direction of exhaust gas in the furnace,
A heat recovery unit provided in the exhaust duct and capable of recovering heat in the exhaust gas;
The boiler characterized by having.

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