JP7454468B2 - Diffuser pipe support structure - Google Patents

Description

The present invention relates to a diffuser tube support structure.

BACKGROUND ART Furnaces have been known in the past, which form a fluidized bed inside and burn combustion materials such as waste (for example, garbage and sludge) and fuel (for example, biomass and waste plastic) in the fluidized bed. In such a furnace, it is necessary to blow fluidized air into the fluidized bed in order to fluidize the fluidized medium (generally sand) constituting the fluidized bed.

For example, Patent Document 1 discloses an aeration pipe that blows fluidized air into a fluidized bed in a furnace. This diffuser pipe extends from the outside of the furnace to the inside of the furnace through the side wall of the furnace. The diffuser pipe is provided with a plurality of ejection ports that eject fluidized air.

Japanese Patent Application Publication No. 2011-226698

By the way, the air diffuser disclosed in Patent Document 1 is a cantilever beam whose tip located inside the furnace is a free end. For this reason, there is a possibility that the air diffuser pipe will vibrate greatly.

From this point of view, it is conceivable to provide a receiving metal fitting in the furnace and to support the distal end portion of the diffuser pipe with this receiving metal fitting. However, since the air diffuser tube expands when it receives heat, it is necessary to allow for that thermal expansion.

For example, the receiving fitting may be constructed in the shape of a container by a cylindrical body and a closing plate, and the distal end of the aeration tube may be inserted into the cylindrical body. Further, in order to facilitate insertion of the diffuser tube into the cylindrical body, the inner diameter of the cylindrical body may be made larger to some extent than the outer diameter of the diffuser tube.

However, in the above structure, the fluid medium flows between the distal end surface of the diffuser tube and the closing plate of the holder through the space between the outer circumferential surface of the diffuser tube and the inner circumferential surface of the cylindrical body. Thermal elongation may become impossible.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a diffuser tube support structure that can prevent a fluid medium from flowing between the distal end surface of the diffuser tube and the closing plate of the receiving metal fitting.

In order to solve the above problems, an air diffuser support structure according to one aspect of the present invention is a structure that supports the tip of an air diffuser tube that blows out fluidized air into a fluidized bed in a furnace, a cylindrical body into which a distal end thereof is inserted, and a closing plate that closes one opening of the cylindrical body, a receiving metal fitting provided in the furnace; a first ring forming a predetermined clearance between the first ring and the inner circumferential surface of the cylindrical body; and a first ring attached to the inner circumferential surface of the cylindrical body so as to be located closer to the closing plate than the first ring. and a second ring forming a predetermined clearance between the air diffuser and the outer circumferential surface of the air diffuser.

According to the above configuration, a labyrinth is formed by the first ring and the second ring between the outer circumferential surface of the diffuser pipe and the inner circumferential surface of the cylindrical body of the receiving fitting. Therefore, it is possible to prevent the fluid medium from flowing into the space between the distal end surface of the diffuser pipe and the closing plate of the receiving fitting.

Further, an air diffuser support structure according to another aspect of the present invention is a structure that supports a tip end of a diffuser tube that blows out fluidized air into a fluidized bed in a furnace, wherein the tip end of the air diffuser tube is located inside the air diffuser tube. A cylindrical body to be inserted, and a receiving fitting provided in the furnace, including a closing plate that closes one opening of the cylindrical body, and a receiving fitting provided on the inner circumferential surface of the cylindrical body so as to be spaced apart from each other in the circumferential direction. a plurality of fixed supports that support the distal end portion of the aeration tube; the aeration tube includes a tube body provided with a plurality of ejection ports; and an end that closes a distal opening of the tube body. It is characterized in that it includes a plate, and a through hole is provided in a portion of the tube body that overlaps with the cylindrical body and/or in the end plate.

According to the above configuration, flowing air is blown out from the through hole within the receiving fitting, and the air passes between the outer circumferential surface of the diffuser pipe and the inner circumferential surface of the cylindrical body and is blown into the furnace. Therefore, it is possible to prevent the fluid medium from flowing into the space between the distal end surface of the diffuser pipe and the closing plate of the receiving fitting.

According to the present invention, it is possible to prevent the fluid medium from flowing into between the distal end surface of the diffuser pipe and the closing plate of the receiving fitting.

It is a schematic block diagram of the furnace provided with the air diffuser pipe. FIG. 3 is a cross-sectional view of the furnace around the diffuser pipe. FIG. 3 is a cross-sectional view of the distal end of the air diffuser pipe and the receiving metal fitting. FIG. 3 is a diagram for explaining the dimensional relationship around the first ring. FIG. 7 is a diagram for explaining the dimensional relationship around the second ring.

FIG. 2 shows a cross-sectional view of a part of a furnace 1 that employs an air diffuser support structure according to an embodiment of the present invention, and FIG. 1 shows a schematic configuration diagram of the furnace 1.

A fluidized bed 10 is formed within the furnace 1 . A plurality of air diffusers 2 (only one is shown in FIGS. 1 and 2) are provided at the lower part of the furnace 1 to blow out fluidized air into the fluidized bed 10. The diffuser pipes 2 are arranged horizontally. The ejection of fluidized air from the air diffuser tube 2 causes the fluidized medium constituting the fluidized bed 10 to flow.

Each diffuser pipe 2 is provided with a plurality of ejection ports 20 for ejecting flowing air. In this embodiment, the jet nozzle 20 is oriented horizontally. That is, flowing air is ejected from the diffuser pipe 2 in the horizontal direction through the ejection port 20. However, the direction of the spout 20 may be downward. Alternatively, each diffuser pipe 2 may be provided with both a horizontal jet port 20 and a downward jet port 20.

The cross-sectional shape of the furnace 1 when the furnace 1 is cut along a horizontal plane may be rectangular or circular. Each diffuser pipe 2 extends so as to straddle side walls 11 and 13 facing each other in the furnace 1 . The inner surfaces of the side walls 11 and 13 are covered with refractory bricks 12 and 14, respectively.

A flowing air supply pipe is connected to the base of the aeration pipe 2 . A fixing metal fitting 3 is provided on the side wall 11 on the root side of the air diffuser 2, and a receiving metal fitting 4 is provided on the side wall 13 on the tip side of the air diffuser 2. The fixing fitting 3 is hollow, the aeration pipe 2 extends through the fixing fitting 3, and the distal end of the aeration tube 2 is supported by the receiving fitting 4.

The diffuser tube 2 includes a tube body 21 provided with a spout 20 and an end plate 24 that closes a distal opening of the tube body 21. A flange 22 for connection to the above-described flowing air supply pipe is provided at the end of the tube body 21 on the root side.

In this embodiment, the jet ports 20 are formed in three rows on each side of the tube body 21 (portions located on both sides in the horizontal direction from the center). The length of each row is shorter than the distance between the fixing metal fitting 3 and the receiving metal fitting 4. However, the formation pattern of the jet ports 20 can be changed as appropriate.

The fixture 3 includes a cylindrical body 31 that penetrates the side wall 11 and the refractory brick 12, and a flange 32 provided at one end of the cylindrical body 31 located outside the furnace 1. Then, the root portion of the diffuser tube 2 is inserted into the cylindrical body 31. On the other hand, a flange 23 that comes into contact with the flange 32 is provided at the root of the air diffuser pipe 2, and the flange 23 is fixed to the flange 32 by bolts (not shown).

The receiving fitting 4 includes a cylindrical body 41 that penetrates the side wall 13 and the refractory brick 14, and a closing plate 42 that closes one opening of the cylindrical body 41 (the opening facing the outside of the furnace 1). Then, the tip of the diffuser tube 2 is inserted into the cylindrical body 41.

In this embodiment, as shown in FIGS. 3A and 3B, at least three guides 5 are fixed to the inner circumferential surface of the cylindrical body 41 so as to contact the outer circumferential surface of the air diffuser 2. The guides 5 are spaced apart from each other in the circumferential direction. In the illustrated example, the number of guides 5 is three, and the guides 5 are arranged at intervals of 120 degrees. However, the number of guides 5 may be four or more.

Each guide 5 has a rod-like shape extending in the axial direction of the cylindrical body 41. Although the cross-sectional shape of each guide 5 is circular in this embodiment, it may be any other shape such as a rectangular shape. Each guide 5 is fixed to the inner peripheral surface of the cylindrical body 41 by, for example, welding.

Each guide 5 extends from approximately the center of the cylindrical body 41 to the vicinity of the closing plate 42 . A first ring 61 and a second ring 62 are arranged between the diffuser pipe 2 and the cylindrical body 41 on the inner side of the furnace 1 than the guide 5 .

More specifically, the first ring 61 is located inside the furnace 1 rather than the second ring 62, and the second ring 62 is located between the first ring 61 and the guide 5. In other words, the second ring 62 is located closer to the closing plate 42 than the first ring 61.

The first ring 61 is attached to the outer peripheral surface of the air diffuser 2 and forms a predetermined clearance between it and the inner peripheral surface of the cylindrical body 41. Regarding the position and shape of the first ring 61, as shown in FIG. t1, the clearance between the first ring 61 and the inner peripheral surface of the cylindrical body 41 is d1, and the angle of repose of the fluid medium is θ,
d1<(L1+t1)×tanθ
It is desirable to satisfy the following. This is because it is possible to prevent the fluid medium from overcoming the first ring 61 above the diffuser pipe 2 . Note that the distance d1 and the thickness t1 are the dimensions of the diffuser tube 2 in the axial direction.

Furthermore, regardless of the distance L1 from one end of the cylindrical body 41 to the first ring 61, the clearance d1 between the first ring 61 and the inner peripheral surface of the cylindrical body 41 must be smaller than t1×tanθ. is desirable. Even if the fluidized medium accumulates between the diffuser pipe 2 and the cylindrical body 41 up to the surface of the first ring 61 facing inward of the furnace 1, the fluidized medium can be prevented from overcoming the first ring 61. It is.

Returning to FIG. 3, the second ring 62 is attached to the inner circumferential surface of the cylindrical body 41, and forms a predetermined clearance between it and the outer circumferential surface of the aeration pipe 2. Regarding the position and shape of the second ring 62, as shown in FIG. When the clearance between 2 and the outer peripheral surface is d2, and the angle of repose of the fluid medium is θ,
d2<(L2+t2)×tanθ
It is desirable to satisfy the following. Even if the fluid medium is deposited between the diffuser pipe 2 and the cylindrical body 41 so that the first ring 61 is buried below the diffuser pipe 2, it is possible to prevent the fluid medium from overcoming the second ring 62. Because you can. Note that the distance d2 and the thickness t2 are the dimensions of the diffuser pipe 2 in the axial direction.

Furthermore, regardless of the distance L2 from the first ring 61 to the second ring 62, it is desirable that the clearance d2 between the second ring 62 and the outer circumferential surface of the air diffuser 2 be smaller than t2×tanθ. Even if the fluidized medium accumulates between the diffuser pipe 2 and the cylindrical body 41 up to the surface of the second ring 62 facing inward of the furnace 1, the fluidized medium can be prevented from overcoming the second ring 62. It is.

Note that the distance L2 from the first ring 61 to the second ring 62 is set to be larger than the amount of displacement of the first ring 61 due to thermal expansion of the air diffuser pipe 2. This is to prevent the first ring 61 from coming into contact with the second ring 62 due to thermal expansion of the air diffuser pipe 2 .

Furthermore, in this embodiment, at least one through hole 25 is provided in the portion of the tube body 21 of the diffuser tube 2 that overlaps with the cylindrical body 41, and at least one (three in the illustrated example) through holes are provided in the end plate 24. A hole 26 is provided. Therefore, flowing air is ejected from the diffuser pipe 2 also within the receiving fitting 4 through the through holes 25 and 26.

Note that in FIG. 3A, the through hole 25 is provided between the second ring 62 and the guide 5, but the through hole 25 is provided between the first ring 61 and the second ring 62. Alternatively, it may be provided inside the furnace 1 rather than the first ring 61. Alternatively, the through hole 25 may be provided between the guides 5 (in the region where the guides 5 exist in the axial direction of the air diffuser 2).

In the diffuser tube support structure configured as described above, the first ring 61 and the second ring 62 create a labyrinth between the outer circumferential surface of the diffuser tube 2 and the inner circumferential surface of the cylindrical body 41 of the receiving fitting 4. It is formed. Therefore, it is possible to prevent the fluid medium from flowing between the distal end surface of the diffuser pipe 2 and the closing plate 42 of the receiving fitting 4.

Moreover, since the first ring 61 attached to the air diffuser 2 is located inside the furnace 1 than the second ring 62 attached to the cylindrical body 41, the tip of the air diffuser 2 is controlled by the first ring 61 and the second ring 62. Insertion of the part into the cylindrical body 41 and withdrawal from the cylindrical body 41 are not hindered.

Furthermore, in this embodiment, since the through holes 25 and 26 are provided in the tube body 21 and the end plate 24 of the air diffuser 2, respectively, the flowing air is ejected from the through holes 25 and 26 within the receiving fitting 4, and Air passes between the outer peripheral surface of the diffuser pipe 2 and the inner peripheral surface of the cylindrical body 41 and is blown into the furnace 1. Therefore, it is possible to more effectively prevent the fluid medium from flowing between the distal end surface of the diffuser pipe 2 and the closing plate 42 of the receiving fitting 4.

(Modified example)
The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the gist of the present invention.

For example, one or both of the through hole 25 provided in the tube body 21 of the air diffuser 2 and the through hole 26 provided in the end plate 24 may be omitted.

Alternatively, when one or both of the through holes 25 provided in the tube body 21 of the air diffuser 2 and the through holes 26 provided in the end plate 24 are employed, the first ring 61 and the second ring 62 may be omitted. . Even with such a configuration, flowing air is blown out from the through holes (25 and/or 26) within the receiving fitting 4, and the air passes between the outer circumferential surface of the diffuser pipe 2 and the inner circumferential surface of the cylindrical body 41. It blows out into the furnace 1. Therefore, it is possible to prevent the fluid medium from flowing between the distal end surface of the diffuser pipe 2 and the closing plate 42 of the receiving fitting 4.

Furthermore, the guide 5 fixed to the inner peripheral surface of the cylindrical body 41 may be omitted. However, if at least three guides 5 are fixed to the inner circumferential surface of the cylindrical body 41 as in the above embodiment, the aeration tube 2 can be opened by simply inserting the tip of the aeration tube 2 into the cylindrical body 41. It can be arranged concentrically with the cylindrical body 41.

(summary)
An air diffuser support structure according to one aspect of the present invention is a structure that supports the tip of an air diffuser that blows out fluidized air into a fluidized bed in a furnace, the tip of the air diffuser being inserted into the interior. a cylindrical body, a receiving metal fitting provided in the furnace, including a closing plate that closes one opening of the cylindrical body, and an inner circumferential surface of the cylindrical body attached to an outer circumferential surface of the air diffuser pipe; a first ring forming a predetermined clearance between the first ring and the outer circumferential surface of the air diffuser, which is attached to the inner circumferential surface of the cylindrical body so as to be located closer to the blocking plate than the first ring; and a second ring forming a predetermined clearance therebetween.

According to the above configuration, a labyrinth is formed by the first ring and the second ring between the outer circumferential surface of the diffuser pipe and the inner circumferential surface of the cylindrical body of the receiving fitting. Therefore, it is possible to prevent the fluid medium from flowing into the space between the distal end surface of the diffuser pipe and the closing plate of the receiving fitting.

The above air diffuser tube support structure may further include at least three guides that are fixed to the inner circumferential surface of the cylindrical body so as to be spaced apart from each other in the circumferential direction and that abut on the outer circumferential surface of the air diffuser tube. According to this configuration, the diffuser tube can be arranged concentrically with the cylindrical body simply by inserting the distal end portion of the diffuser tube into the cylindrical body.

The distance from one end of the cylindrical body located inside the furnace to the first ring is L1, the thickness of the first ring is t1, and the distance between the first ring and the inner peripheral surface of the cylindrical body When the clearance of is d1 and the angle of repose of the fluidized medium constituting the fluidized bed is θ,
d1<(L1+t1)×tanθ
may be satisfied. According to this configuration, it is possible to prevent the fluid medium from overcoming the first ring above the diffuser tube.

The distance from the first ring to the second ring is L2, the thickness of the second ring is t2, the clearance between the second ring and the outer peripheral surface of the diffuser pipe is d2, and the fluidized bed is configured. When the angle of repose of the fluid medium is θ,
d2<(L2+t2)×tanθ
may be satisfied. According to this configuration, even if the fluid medium is deposited between the diffuser pipe and the cylindrical body so that the first ring is buried below the diffuser pipe, the fluid medium is prevented from overcoming the second ring. I can do it.

The aeration tube includes a tube body provided with a plurality of ejection ports, and an end plate that closes a distal opening of the tube body, and a portion of the tube body that overlaps with the cylindrical body and/or the end plate. may be provided with a through hole. According to this configuration, flowing air is blown out from the through hole within the receiving fitting, and the air passes between the outer circumferential surface of the diffuser pipe and the inner circumferential surface of the cylindrical body and is blown into the furnace. Therefore, it is possible to more effectively prevent the fluid medium from flowing between the distal end surface of the diffuser pipe and the closing plate of the receiving fitting.

Further, an air diffuser support structure according to another aspect of the present invention is a structure that supports a tip end of a diffuser tube that blows out fluidized air into a fluidized bed in a furnace, wherein the tip end of the air diffuser tube is located inside the air diffuser tube. A cylindrical body to be inserted, and a receiving fitting provided in the furnace, including a closing plate that closes one opening of the cylindrical body, and a receiving fitting provided on the inner circumferential surface of the cylindrical body so as to be spaced apart from each other in the circumferential direction. a plurality of fixed supports that support the distal end portion of the aeration tube; the aeration tube includes a tube body provided with a plurality of ejection ports; and an end that closes a distal opening of the tube body. It is characterized in that it includes a plate, and a through hole is provided in a portion of the tube body that overlaps with the cylindrical body and/or in the end plate.

According to the above configuration, flowing air is blown out from the through hole within the receiving fitting, and the air passes between the outer circumferential surface of the diffuser pipe and the inner circumferential surface of the cylindrical body and is blown into the furnace. Therefore, it is possible to prevent the fluid medium from flowing into the space between the distal end surface of the diffuser pipe and the closing plate of the receiving fitting.

1 Furnace 10 Fluidized bed 2 Diffuser pipe 21 Pipe body 24 End plate 25, 26 Through hole 4 Receiver 41 Cylindrical body 42 Closure plate 5 Guide 61 First ring 62 Second ring

Claims (6)

A structure that supports the tip of a diffuser pipe that blows fluidized air into a fluidized bed in a furnace,
A receiving metal fitting provided in the furnace, including a cylindrical body into which the tip of the air diffuser is inserted, and a closing plate that closes one opening of the cylindrical body;
a first ring that is attached to the outer circumferential surface of the air diffuser and forms a predetermined clearance with the inner circumferential surface of the cylindrical body;
a second ring that is attached to the inner circumferential surface of the cylindrical body so as to be located closer to the closure plate than the first ring, and that forms a predetermined clearance between the second ring and the outer circumferential surface of the air diffuser pipe;
A diffuser pipe support structure comprising: The diffuser tube support structure according to claim 1, further comprising at least three guides fixed to the inner circumferential surface of the cylindrical body so as to be spaced apart from each other in the circumferential direction and contacting the outer circumferential surface of the diffuser tube. The distance from one end of the cylindrical body located inside the furnace to the first ring is L1, the thickness of the first ring is t1, and the distance between the first ring and the inner peripheral surface of the cylindrical body When the clearance of is d1 and the angle of repose of the fluidized medium constituting the fluidized bed is θ,
d1<(L1+t1)×tanθ
The diffuser pipe support structure according to claim 1 or 2, which satisfies the following. The distance from the first ring to the second ring is L2, the thickness of the second ring is t2, the clearance between the second ring and the outer peripheral surface of the diffuser pipe is d2, and the fluidized bed is configured. When the angle of repose of the fluid medium is θ,
d2<(L2+t2)×tanθ
The diffuser pipe support structure according to any one of claims 1 to 3, which satisfies the following. The aeration tube includes a tube body provided with a plurality of jet ports, and an end plate that closes a distal opening of the tube body,
The diffuser tube support structure according to any one of claims 1 to 4, wherein a through hole is provided in a portion of the tube body that overlaps with the cylindrical body and/or in the end plate. A structure that supports the tip of a diffuser pipe that blows fluidized air into a fluidized bed in a furnace,
A receiving metal fitting provided in the furnace, including a cylindrical body into which the tip of the air diffuser is inserted, and a closing plate that closes one opening of the cylindrical body;
a plurality of supports that support the distal end portion of the air diffuser tube and are fixed to the inner circumferential surface of the cylindrical body so as to be spaced apart from each other in the circumferential direction;
The aeration tube includes a tube body provided with a plurality of jet ports, and an end plate that closes a distal opening of the tube body,
A diffuser tube support structure, wherein a through hole is provided in a portion of the tube body that overlaps with the cylindrical body and/or in the end plate.

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