WO2019043830A1 - Air nozzle, outer casing, boiler, power generation system, and method for replacing air nozzle outer casing - Google Patents

Abstract

The purpose of the invention is to provide an air nozzle, an outer casing, a boiler, a power generation system, and a method for replacing an air nozzle outer casing that can reduce the workload involved in repair operations. This air nozzle (12) comprises: a cylindrical inner casing (35) that is fixed to the bottom of a furnace; a cylindrical outer casing (36) in which the inner casing (35) is disposed; an inner casing blocking member (37) that has a column portion (44) fixed to the top end face (35d) of the inner casing (35) and extending vertically upward and that blocks an upper opening (35a) of the inner casing (35); and a first outer casing blocking member (38) that has a columnar cylindrical portion (46) extending vertically upward and that blocks an upper opening (36a) of the outer casing (36). The column portion (44) is housed in the columnar cylindrical portion (46) so that the outer circumferential face (44a) of the column portion (44) lies along the inner circumferential face (46a) of the columnar cylindrical portion (46). The upper end of the column portion (44) and the columnar cylindrical portion (46) are fixed by welding.

Description

Air nozzle, outer cylinder, boiler, power generation system, and method of replacing air nozzle outer cylinder

The present invention relates to an air nozzle, an outer cylinder, a boiler, a power generation system, and a method of replacing an outer cylinder of an air nozzle.

A boiler (eg, circulating flow) that improves combustion efficiency by flowing fuel and fluidized sand (for example, particles mainly composed of SiO 2 such as river sand) in the furnace with air supplied from the furnace bottom to form a fluidized bed. A bed boiler (CFB: Circulating Fluidized Bed) and a bubbling fluid bed boiler (BFB: Bubbling Fluidized Bed) are known.

Such boilers are provided at the bottom of the furnace with a number of air nozzles which supply air into the furnace in order to form a fluidized bed. Some air nozzles used in such boilers have a double-pipe structure to prevent backflow of fluidized sand in the fluidized bed. As an air nozzle of double pipe structure, there is an air nozzle of patent documents 1, for example.
The air nozzle of Patent Document 1 has an inner pipe and an outer pipe, and the inner pipe and the outer pipe are respectively provided with an upper vent and a lower vent, and air is passed from the inner pipe through the upper vent. Enter the outer tube and spout from the lower vent.

Japanese Patent Application Laid-Open No. 7-293821

By the way, in order to fluidize the fluid sand etc. in a furnace uniformly and to form a uniform fluid bed, the installation mode of an air nozzle becomes important. Specifically, the longitudinal axis direction of each air nozzle is provided vertically in the vertical direction, and the height of each air nozzle is aligned vertically in the vertical direction, and the outer cylinder of each air nozzle is arranged. It is important that the positions of the air jet holes provided at the center of the furnace are aligned to the same level with the bottom plate of the furnace bottom. Therefore, when fixing the air nozzle to the furnace bottom, it is necessary to confirm and adjust at such points, and to perform careful alignment and fixing, which requires work time.

On the other hand, the outer cylinder of the air nozzle is formed with an air vent (air outlet) for supplying air into the furnace, but in the vicinity of the air outlet, the sand discharged from the air outlet flows Etc. are caught and a part of the caught fluidized sand collides with the outer cylinder. When the flowing sand or the like collides, the outer cylinder may be ground by the colliding flowing sand, which may accelerate the wear of the outer cylinder. If the outer cylinder wears, the air can not be suitably supplied into the furnace, and it becomes difficult to form a uniform fluidized bed. Therefore, the air nozzle is periodically checked and the air nozzle in which the wear has progressed It is necessary to repair for.
In the said patent document 1, it is not considered about the attachment aspect of each member with which an air nozzle is provided. Such an air nozzle can not be disassembled separately, and when repairing the air nozzle, the entire air nozzle may have to be removed from the furnace. When the entire air nozzle is removed from the furnace, after the repair, an operation to attach the air nozzle to the furnace occurs again, and it is necessary to perform the above-mentioned careful alignment and fixation at this time. Furthermore, since a large number of air nozzles are installed at the bottom of the furnace, a series of air supply nozzles that select an air nozzle that needs repair depending on the degree of wear, remove it, and attach a replacement air nozzle The workload incurred during the repair operation could increase.

This invention is made in view of such a situation, Comprising: The air nozzle which can reduce the operation | work burden which arises at the time of repair operation, an outer cylinder, a boiler, an electric power generation system, and replacement | exchange of the outer cylinder of an air nozzle. Intended to provide a method.

In order to solve the above problems, the air nozzle, the outer cylinder, the boiler, the power generation system, and the method for replacing the outer cylinder of the air nozzle according to the present invention employ the following means.
The air nozzle according to one aspect of the present invention is an air nozzle that fluidizes a fluid material in the furnace by supplying a gas into the furnace, and is fixed to the furnace bottom of the furnace, and from the furnace bottom A cylindrical inner cylinder which extends vertically upward and is supplied with gas, a cylindrical outer cylinder in which the inner cylinder is disposed and which supplies the gas discharged from the inner cylinder into the furnace, and vertically upward A first connection portion fixed to the upper end portion of the outer cylinder, and a second connection portion fixed to the upper end portion of the inner cylinder, having a pillar portion extending vertically upward The column portion is housed inside the cylinder portion such that the outer peripheral surface of the column portion is along the inner peripheral surface of the cylinder portion, and the upper end portion of the column portion and the cylinder portion are fixed by welding It is done.

In the above configuration, the first connection portion fixed to the outer cylinder has the cylindrical portion, and the second connection portion fixed to the inner cylinder has the pillar portion. In addition, the column portion is housed inside the cylinder portion so that the outer peripheral surface of the column portion is along the inner peripheral surface of the cylinder portion. Thereby, when attaching an outer cylinder to the inner cylinder fixed to the furnace bottom, while a pillar part controls horizontal movement of a cylinder part, a pillar part regulates an inclination to a pillar part of a cylinder part. Thus, when the outer cylinder is attached to the inner cylinder, the horizontal relative position between the inner cylinder and the outer cylinder and the axial direction of the outer cylinder with respect to the inner cylinder when the outer cylinder is attached to the inner cylinder. The aspect (posture in the vertical direction) can be easily made to have a predetermined relative position and an axial aspect.
Further, in the above configuration, the gas (air) flowing through the inside of the inner cylinder is supplied into the furnace through the inside of the outer cylinder, so the relative position between the inner cylinder and the outer cylinder and the axial direction are predetermined. In this way, the supply mode of the gas supplied into the furnace can be predetermined, and fluidization of the fluid material in the furnace can be suitably performed.
In addition, the predetermined relative position in the horizontal direction between the inner cylinder and the outer cylinder and the axial direction form, for example, a position in which the longitudinal axis of the outer cylinder is substantially the same as the longitudinal axis of the inner cylinder (a predetermined error The relative position and the axial aspect that will be the matching position).

In addition, since the fluid material flows in the furnace, if the air material supplied from the air nozzle into the furnace causes the fluid material to be caught in the vicinity of the outer cylinder and collides with the outer cylinder, etc. Wear and thinning may be promoted. When the outer cylinder is worn or reduced in thickness, the gas is not suitably supplied from the outer cylinder into the furnace, and the fuel efficiency of the furnace may be reduced because uniform flow of the fluid material can not be obtained. Therefore, it is preferable to replace the worn and reduced outer cylinder instead of the entire air nozzle.
In the above configuration, the weld fixing portion between the column portion and the cylinder portion is scraped off, or the column portion and the cylinder portion are cut in a substantially horizontal direction at a position vertically lower than the weld fixing portion between the column portion and the cylinder portion By removing the weld fixing portion by doing this, the fixation between the column portion and the cylindrical portion is released. That is, the fixation between the inner cylinder and the outer cylinder is also released. Thereby, the outer cylinder can be removed from the inner cylinder which is fixed to the furnace bottom.
In addition, since the column portion is welded and fixed to the cylinder portion using the upper end portion, the column portion is vertically lower than the welding fixed portion between the column portion and the cylinder portion, and is also predetermined vertically upper than the lower end of the column portion It is possible to separate at a position longer than the length of Here, the predetermined length is a length in which the column portion is accommodated inside the cylindrical portion and the upper end portion of the column portion and the cylindrical portion can be welded and fixed. As a result, even if the weld fixing portion with the cylindrical portion is removed, the length of the pillar portion in the vertical vertical direction remains equal to or greater than a predetermined length. Therefore, even after the outer cylinder is removed from the inner cylinder, the replacement outer cylinder can be attached to the inner cylinder again. Furthermore, even if the rewelding fixing portion between the column and the cylinder is removed again, the vertical vertical length of the column is such that the vertical vertical length of the column remains a predetermined length or more. If the setting is set, the outer cylinder can be removed from the inner cylinder a plurality of times, and the replacement outer cylinder can be attached to the inner cylinder.

Thus, in the above configuration, the outer cylinder can be replaced without removing the inner cylinder fixed to the furnace bottom from the furnace bottom. When the inner cylinder is newly fixed to the furnace bottom, the longitudinal axis direction of the inner cylinder is provided in the vertical direction to realize suitable fluidization of the flowing material, and the reference portion of the inner cylinder is the furnace bottom In order to align the height positions of the air vents from the outer cylinder by aligning them at a predetermined height position for the case, careful alignment work is required, but in the above configuration, when replacing the outer cylinder Since the inner cylinder is not removed from the furnace bottom, alignment of the inner cylinder with the furnace bottom can be omitted. Also, when attaching the outer cylinder to the inner cylinder again, the column fixed to the inner cylinder can be inserted so as to be inserted into the cylinder fixed to the outer cylinder. The predetermined relative position and axial direction can be easily achieved.
Therefore, the replacement work of the outer cylinder can be facilitated, and the operation time required for the replacement work of the outer cylinder can be shortened. Therefore, the work load which arises at the time of repair work of an air nozzle can be eased.

Further, in the air nozzle according to one aspect of the present invention, the column portion and the cylinder portion may be engaged in a state of intermediate fitting or gap fitting.

In the above configuration, the column portion and the cylinder portion are engaged in the state of the intermediate fitting or the gap fitting. Thus, when the outer cylinder is attached to the inner cylinder, the column portion more preferably restricts the horizontal movement from the predetermined position of the cylinder portion and the inclination of the column portion of the cylinder portion with respect to the axial direction. Therefore, the relative position in the horizontal direction between the inner cylinder and the outer cylinder and the axial direction of the outer cylinder with respect to the inner cylinder can be more easily set to the predetermined relative position and axial direction.

In the air nozzle according to one aspect of the present invention, the lower end surface of the cylindrical portion may be disposed on the upper end surface of the inner cylinder.

In the above configuration, the lower end surface of the cylindrical portion is disposed on the upper end surface of the inner cylinder. Thereby, when attaching an outer cylinder with respect to an inner cylinder, the outer cylinder to which the cylinder part and the cylinder part are being fixed can be arrange | positioned on the basis of the upper end surface of an inner cylinder. Therefore, the relative position between the inner cylinder and the outer cylinder in the vertical vertical direction can be easily made to be a predetermined relative position. Since the inner cylinder remains fixed to the furnace bottom, the height of the reference portion of the outer cylinder with respect to the furnace bottom in the furnace can be determined by setting the relative position between the inner cylinder and the outer cylinder in the vertical vertical direction to a predetermined relative position. The position can be a predetermined height position.

Further, in the air nozzle according to one aspect of the present invention, the pillar portion is formed with an engagement portion whose outer peripheral surface is along the inner peripheral surface of the cylindrical portion and a diameter smaller than that of the engagement portion. You may provide the small diameter part extended vertically upwards from the upper end of the joint part.

In the above configuration, the pillar portion includes the engaging portion and the small diameter portion whose diameter is smaller than that of the engaging portion vertically above the upper end of the engaging portion. That is, the distance between the outer peripheral surface of the small diameter portion and the inner peripheral surface of the cylindrical portion is longer than the distance between the outer peripheral surface of the engaging portion and the inner peripheral surface of the cylindrical portion. Thereby, even if deformation, damage or the like occurs in part of the small diameter portion other than the engaging portion, it is difficult to make the small diameter portion having a small diameter contact with the inner circumferential surface of the cylindrical portion it can.
Therefore, when attaching the outer cylinder to the inner cylinder, it is possible to easily insert the cylindrical portion and the column portion other than the engaging portion, and the engaging portion reliably aligns the outer cylinder and the inner cylinder. It can be carried out. Furthermore, when removing the outer cylinder from the inner cylinder, even if the small diameter portion with small diameter is deformed or damaged, it can be removed smoothly. Therefore, since management of parts other than the engaging part can be simplified, handling can be facilitated.

In the air nozzle according to one aspect of the present invention, the second connection portion has a disk portion provided at the lower end of the pillar portion, and the lower surface of the disk portion is at the upper end portion of the inner cylinder. It may be placed.

In the above configuration, the lower surface of the disk portion is placed on the upper end portion of the inner cylinder. Thereby, the relative position of the 2nd connection part and the up-and-down direction of an inner cylinder turns into a predetermined relative position. Since the outer cylinder and the inner cylinder are connected via the first connection portion and the second connection portion, by setting the relative position between the second connection portion and the inner cylinder in the vertical direction to be a predetermined relative position. The relative position between the outer cylinder and the inner cylinder can also be suitably set to a predetermined relative position.

In the air nozzle according to one aspect of the present invention, the inner cylinder includes a cylindrical main body portion and a first projecting portion protruding outward in the radial direction from the upper end portion of the main body portion; The portion has a second protrusion projecting radially outward from the outer peripheral end of the disk portion, and the diameter of the disk portion is formed substantially the same as the diameter of the main body portion, and the inner cylinder and The second connection portion may be fixed by welding and fixing the outer end portion of the first protrusion and the outer end portion of the second protrusion.

In the above configuration, the inner cylinder and the second connection portion are fixed by welding and fixing the outer end portion of the first protruding portion and the outer end portion of the second protruding portion. As a result, the first projection and the second projection are cut in the substantially vertical plane direction at a position inward in the radial direction with respect to the weld fixing portion of the first projection and the second projection, or the first projection and the second projection are The weld fixing portion can be removed by scraping to a position in the radially inward direction. When the welding fixation portion is removed, the fixation between the inner cylinder and the second connection portion is released. Therefore, for example, even when the pillar portion of the second connection portion is damaged or the like, the second connection portion can be removed from the inner cylinder and replaced without removing the inner cylinder fixed to the furnace bottom.

The outer cylinder of the air nozzle according to one aspect of the present invention is an outer cylinder of an air nozzle that fluidizes the fluid material in the furnace by supplying the gas discharged from the inner cylinder disposed therein to the inside of the furnace. And a second connecting portion fixed to the upper end portion of the main body portion, the cylindrical portion having the cylindrical main body portion and the vertically extending upper portion, the cylindrical portion being the upper end portion of the inner cylinder And the column portion extending vertically upward of the first connection portion fixed to the housing is accommodated inside with the outer peripheral surface of the column portion extending along the inner peripheral surface of the cylindrical portion, and the cylindrical portion is Welded with the upper end.

In the above configuration, since the column portion fixed to the inner cylinder regulates the movement of the cylinder portion, etc., when the outer cylinder is attached to the inner cylinder, the horizontal relative position between the inner cylinder and the outer cylinder and the inside The axial aspect of the outer cylinder with respect to the cylinder can be easily made into a predetermined relative position and an axial aspect. Since it can be attached to the inner cylinder at a predetermined relative position and in an axial direction, the supply mode of the gas supplied into the furnace is also predetermined, and fluidization of the fluid material in the furnace is preferably performed. Can.
Further, in the above configuration, since the outer cylinder can be replaced without removing the inner cylinder fixed to the furnace bottom from the furnace bottom, when replacing the outer cylinder, the alignment work of the inner cylinder with respect to the furnace bottom is omitted. be able to. Also, when attaching the outer cylinder to the inner cylinder again, the column can be attached so as to be inserted into the cylinder, so that the relative position and the axial direction can be easily set. it can.
Therefore, the replacement work of the outer cylinder can be greatly facilitated, and the time required for the replacement work of the outer cylinder can be shortened.

In the outer cylinder of the air nozzle according to one aspect of the present invention, the length in the vertical direction of the region of the cylindrical portion in which the column portion is accommodated is the length in the radial direction of the column portion. On the other hand, it may be set to a range of 1/2 or more and 5 or less.
In the outer cylinder of the air nozzle according to one aspect of the present invention, the length in the vertical direction of the region of the cylindrical portion in which the column portion is accommodated is the length in the radial direction of the column portion. On the other hand, it may be set to a range longer than 1 time and 5 times or less.

In the above configuration, the length in the vertical direction of the region accommodating the column portion in the cylindrical portion is a predetermined length relative to the radial length of the column portion accommodated in the cylindrical portion. Secured. Thereby, the relative position and axial direction aspect of an inner cylinder and an outer cylinder can be certainly made to a predetermined thing. The length in the vertical direction of the region of the cylindrical portion in which the column portion is accommodated is longer than one time the radial length of the column portion accommodated in the cylindrical portion. It is more preferable if it is in the range of twice or less.

A boiler according to one aspect of the present invention includes a furnace in which a fluid material is caused to flow internally by the air nozzle having the above-described air nozzle or the air nozzle having the above-described outer cylinder, and a flue in which the combustion gas generated in the furnace flows. And a heat exchanger provided in the flue to generate steam by the heat of the combustion gas.

A power generation system according to an aspect of the present invention includes the above-described boiler, a steam turbine driven by steam generated by the boiler, and a generator that generates power by a driving force of the steam turbine.

A method of replacing an outer cylinder of an air nozzle according to an aspect of the present invention is an air nozzle that fluidizes a fluid material in the furnace by supplying a gas into the furnace, and is fixed to the furnace bottom of the furnace. And a cylindrical inner cylinder extending vertically upward from the furnace bottom and supplied with gas, and the inner cylinder disposed inside, and cylindrical having a gas discharged from the inner cylinder supplied into the furnace. It has an outer cylinder and a cylinder portion extending vertically upward, has a first connection portion fixed to the upper end portion of the outer cylinder, and a pillar portion extending vertically upward, and is fixed to the upper end portion of the inner cylinder A second connection portion, and the column portion is housed inside the cylinder portion so that the outer peripheral surface of the column portion is along the inner peripheral surface of the cylinder portion, and the upper end portion of the column portion and the A method of replacing an outer cylinder of an air nozzle, to which a tubular portion is welded and fixed, and removing the portion that is welded and fixed A step of removing the outer cylinder from the inner cylinder after the removing step, an attaching step of attaching a replacement outer cylinder to the inner cylinder after the removing step, and a step of attaching the replacement outer cylinder after the removing step; And a fixing step of welding and fixing the upper end portion of the pillar portion and the cylindrical portion.

According to the present invention, it is possible to reduce the work load generated at the time of repair work.

It is a schematic block diagram of the electric power generation system concerning the embodiment of the present invention. It is the side view which showed the inside of the furnace of FIG. 1 typically. It is a longitudinal cross-sectional view of the air nozzle concerning a 1st embodiment of the present invention. It is a figure which shows the replacement | exchange method of the outer cylinder of the air nozzle of FIG. It is a longitudinal cross-sectional view of the air nozzle concerning a 2nd embodiment of the present invention. It is a longitudinal cross-sectional view of the air nozzle concerning a 3rd embodiment of the present invention.

Hereinafter, an embodiment of an air nozzle, an outer cylinder, a boiler, a power generation system, and a method of replacing an outer cylinder of an air nozzle according to the present invention will be described with reference to the drawings.
First Embodiment
Hereinafter, a first embodiment of the present invention will be described using FIGS. 1 to 4.
As shown in FIG. 1, the power generation system 1 according to the present embodiment is rotationally driven by steam generated by a circulating fluidized bed boiler (CFB: Circulating Fluidized Bed) 2 and a circulating fluidized bed boiler 2 as a boiler that generates steam. And a generator 4 that generates electric power by the driving force of the steam turbine 3.
In the following description, "upper" indicates the vertically upward direction, and "lower" indicates the vertically downward direction.

The circulating fluidized bed boiler 2 is a fluidized bed furnace (hereinafter referred to as "furnace furnace") 5 which has flowing fluidized sand (for example, particles mainly composed of SiO2 such as river sand) inside and fuel that supplies fuel to the furnace 5. The system includes a supply device 6, a flue 7 through which the combustion gas generated by the furnace 5 flows, and a plurality of heat exchangers 8 provided in the flue 7. The circulating fluidized bed boiler 2 can burn a wide range of fuels, and coal (bituminous coal, sub-bituminous coal, lignite, anthracite etc.), petroleum coke, woody biomass, paper sludge, RPF (Refuse Paper & Plastic Fuel) can be used as fuel. Waste tires, dewatered sludge, municipal waste, etc. can be adopted.
In addition, the fuel supply apparatus 6 shown in FIG. 1 is an example at the time of employ | adopting coal as a fuel. In the present embodiment, since the internal pressure of the furnace 5 is slightly higher than the atmospheric pressure, the fuel supply device 6 is provided with a rotary valve 10 and a seal air supply device (not shown) to prevent backflow of combustion gas and the like to the fuel supply system. It is done.

As shown in FIG. 1, the furnace 5 forms a fluidized bed of fluid material (fuel and fluidized sand) by air (gas) supplied from an air nozzle 12 provided in the furnace bottom 11. By forming the fluidized bed in this manner, the circulating fluidized bed boiler 2 promotes mixing of the fuel in the furnace 5 (comber), fluidized sand, and air, and aims to improve the combustion efficiency. During normal operation of the circulating fluidized bed boiler 2, air is supplied as a gas from the air nozzle 12. However, in the case of in-furnace purge, etc., when inert gas (nitrogen gas etc.) is introduced. is there.

Further, circulating particles (fluidized sand and unburned fuel) that fly out from the furnace 5 together with the exhaust gas are separated into combustion gas and circulating particles by the cyclone 13 provided on the outlet side of the furnace 5. The circulating particles separated and collected by the cyclone 13 are returned to the furnace 5 again via the seal pot 14 and the external heat exchanger 15. As described above, in the circulating fluidized bed boiler 2 according to the present embodiment, the combustion efficiency is improved by adopting a system in which fluidized sand and unburned fuel are circulated. Further, by adjusting the branching ratio of the circulating particles sent to the external heat exchanger 15 by the ash takeout valve 16, the temperature inside the furnace 5 can be adjusted. Note that air for flowing circulating particles is supplied from the air blower 17 to the external heat exchanger 15.

The combustion gas separated by the cyclone 13 flows in the flue 7 and exchanges heat with a plurality of heat exchangers 8 provided in the flue 7. In the heat exchanger 8, steam is generated by heat exchange with the combustion gas. The generated steam is sent to the steam turbine 3 to rotationally drive the steam turbine 3. When the steam turbine 3 is rotationally driven, power is generated by a generator 4 coaxially connected to the steam turbine 3. On the other hand, after passing through the air preheater 22 and the bag filter 23, the combustion gas heat-exchanged with the heat exchanger 8 is released to the atmosphere from a chimney (not shown).

The furnace 5 is provided with a plurality of air nozzles 12 for flowing a fluid material in the furnace 5 and a combustion air supply unit 26 for supplying combustion air. While the furnace 5 used in the fine powder combustion method partially exceeds about 1500 ° C., the furnace 5 used in the circulating fluidized bed boiler 2 has a uniform temperature in the furnace and, for example, 800 to 900 ° C. It is controlled. Therefore, the circulating fluidized bed boiler 2 can suppress the generation amount of thermal NOx (generated NOx depending on the combustion temperature), and further supply the NOx generation amount and limestone into the furnace 5 to perform in-furnace desulfurization (CaCO ₃ → It also becomes possible to perform CaO + CO ₂ , CaO + SO ₂ + 1 / 2O ₂ → CaSO ₄ ).

A plurality of combustion air supply units 26 are provided. Each of the combustion air supply units 26 ejects part of the air preheated by the air preheater 22 from an FDF (Forced Delivery Fan) 27 into the furnace as combustion air. The combustion air jetted out is distributed substantially uniformly to the respective combustion air supply portions 26 by the air chamber 28. For this reason, a uniform fluidized bed is formed in the furnace 5, and the temperature in the furnace becomes relatively uniform.

As shown in FIG. 2, the air nozzles 12 are provided to penetrate the furnace bottom 11, and a plurality (for example, several hundreds) of the air nozzles 12 are provided across the furnace bottom 11. The inner cylinder 35 of each air nozzle 12 is provided to vertically penetrate the furnace bottom 11 of the furnace 5. That is, the upper part of the inner cylinder 35 is located inside the furnace 5, the lower part of the inner cylinder 35 is located inside the air box 29, and the lower opening 35 b of the inner cylinder 35 is opened inside the air box 29.
Each air nozzle 12 is installed so that the longitudinal axis direction is substantially vertical vertical direction, is installed substantially perpendicular to the area of the horizontal surface of the furnace bottom 11, and the angle θ between the inner cylinder 35 and the furnace bottom 11 is It is arranged to be approximately 90 degrees. Although the angle θ is not limited to 90 degrees, it is preferable that the angle θ be managed at ± 1 to 3 degrees with respect to 90 degrees. In addition, the inner cylinder 35 may be welded and fixed to the furnace bottom 11 via the sleeve 40. Specifically, as shown in FIG. 4, in a region where the inner cylinder 35 penetrates the furnace bottom 11, the sleeve 40 contacts the outer peripheral surface 35 c of the inner cylinder 35 with the inner peripheral surface of the cylindrical sleeve 40. The upper end and the lower end of the sleeve 40 and the outer peripheral surface 35c of the inner cylinder 35 are welded and fixed at welds W1 and W2, and the outer peripheral surface of the sleeve 40 and the lower surface of the furnace bottom plate 32 constituting the furnace bottom 11 are welded It is welded and fixed at W3.

Further, in the present embodiment, the air preheated and sent from the FDF 27 by the air preheater 22 is supplied into the furnace 5 by the plurality of air nozzles 12 via the air box 29.
In the present embodiment, the furnace bottom 11 of the furnace 5 is configured such that the fireproof material 33 covers the water-cooling wall including the water-cooling pipe 31 and the furnace bottom plate 32 from the upper side (see FIG. 4).

Next, a detailed structure of the air nozzle 12 according to the present embodiment will be described with reference to FIG.
The air nozzle 12 communicates the furnace 5 with the air box 29 and extends in the vertical direction, a cylindrical inner cylinder 35 extending in the vertical direction, and a cylindrical outer cylinder 36 that surrounds the upper part of the inner cylinder 35 inside the furnace 5 from the outside An inner cylinder closing member (second connecting portion) 37 closing the upper opening 35a of the cylinder 35, a first outer cylinder closing member (first connecting portion) 38 closing the upper opening 36a of the outer cylinder 36, and a lower portion of the outer cylinder 36 And a second outer cylinder closing member 39 closing the opening 36b. The inner cylinder 35 and the outer cylinder 36 are preferably made of a stainless steel material in view of heat resistance, oxidation resistance, and abrasion resistance, and are formed of, for example, SUS310, SUS304, SUS316 or the like.

As shown in FIG. 3, a plurality of inner cylinder vents 41 penetrating in the horizontal direction are formed in the upper portion of the inner cylinder 35. The plurality of inner cylinder vents 41 are formed at equal intervals over the entire area along the circumferential direction of the inner cylinder 35, and constitute a row of inner cylinder vents. One row of inner cylinder vents is formed in two rows along the vertical direction.

The inner cylinder closing member 37 has a disk portion 43 fixed to the upper end surface 35 d of the inner cylinder 35 and a cylindrical portion (column portion) 44 extending upward from the upper surface 43 a of the disk portion 43.
The diameter of the disk portion 43 is formed to be substantially the same as the outer diameter of the inner cylinder 35. The disk portion 43 is closed by covering the entire upper opening 35a of the inner cylinder 35 from above, and the lower end of the outer peripheral surface of the disk portion 43 and the upper end of the outer peripheral surface 35c of the inner cylinder 35 are welded and fixed at the weld portion W4. ing.
The cylindrical portion 44 is fixed at substantially the center of the upper surface 43 a of the disc portion 43 such that the longitudinal central axis of the cylindrical portion 44 and the longitudinal central axis of the inner cylinder 35 substantially coincide with each other. The disc portion 43 and the cylindrical portion 44 may be fixed to separate members by welding or the like, or may be integrally cut out from one member.

The first outer cylinder closing member 38 is a circular ring 45 positioned and mounted by being in contact with the upper surface 43 a of the disk portion 43 of the inner cylinder closing member 37, and a cylindrical shape extending upward from the upper surface of the circular ring 45 And a cylindrical portion (cylindrical portion) 46 of FIG.
An opening 45 a is formed substantially at the center of the annular portion 45. Further, the outer diameter of the annular portion 45 is formed to be substantially the same as the inner diameter of the outer cylinder 36. That is, the outer diameter of the annular portion 45 is formed larger than the outer diameter of the inner cylinder 35 and the diameter of the disk portion 43. The annular portion 45 covers the outer cylinder 36 from the upper side, and the upper end surface 36 c of the outer cylinder 36 and the outer end of the annular portion 45 are welded and fixed at the welding portion W6.
The cylindrical portion 46 is fixed at substantially the center of the upper surface of the annular portion 45 so as to communicate with the opening 45 a so that the longitudinal central axis of the cylindrical portion 46 and the longitudinal central axis of the outer cylinder 36 substantially coincide. .
The annular portion 45 and the cylindrical portion 46 may be fixed to separate members by welding or the like, or may be integrally cut out from one member.

Further, a cylindrical portion 44 fixed to the inner cylinder 35 is accommodated in the cylindrical portion 46 fixed to the outer cylinder 36. The outer peripheral surface 44a of the cylindrical portion 44 is disposed along the inner peripheral surface 46a of the cylindrical portion 46, and a slight gap is formed between the outer peripheral surface 44a of the cylindrical portion 44 and the inner peripheral surface 46a of the cylindrical portion 46. α1 (not shown) is provided. That is, the cylindrical portion 44 and the cylindrical portion 46 are in a state of intermediate fit or clearance fit, and more preferably in a state of clearance fit close to the intermediate fit (for example, the tolerance zone class of the hole of the cylindrical portion 46 is H9, and the tolerance zone class of the axis of the cylindrical portion 44 is engaged at h9). As described above, the cylindrical portion 46 and the cylindrical portion 44 can be manually pushed in and engaged with each other by a close state due to the slight gap α1, and the center of the inner cylinder 35 can be reduced by the small gap α1. The shaft and the central axis of the outer cylinder 36 are at substantially the same position (the position of the alternate long and short dash line C1 in FIG. 3 etc.).
Further, the first outer cylinder closing member 38 and the inner cylinder closing member 37 are fixed by welding. Specifically, the upper end surface of the cylindrical portion 46 and the upper end portion of the cylindrical portion 44 are fixed by welding at the welding portion W5. In the present embodiment, the height of the cylindrical portion 44 is higher than the height of the cylindrical portion 46 by a predetermined length S. The length S is a height necessary for welding and is set to, for example, 5 mm to 10 mm in the present embodiment.

The outer cylinder 36 extends downward from the outer end of the annular portion 45.
At the lower part of the outer cylinder 36, a plurality of outer cylinder vents 42 penetrating in the horizontal direction are formed. The plurality of outer cylinder vents 42 are formed at equal intervals over the entire area along the circumferential direction of the outer cylinder 36. The outer cylinder air hole 42 formed in the outer cylinder 36 is formed at a position lower than the inner cylinder air hole 41 formed in the inner cylinder 35. Thereby, it is possible to suppress the influence on the ejection of air due to the inflow of the fluid material in the furnace 5 into the inside of the inner cylinder 35.
As shown in FIG. 4, the heights of the plurality of air nozzles 12 provided in the furnace 5 with respect to the upper surface 11 a of the furnace bottom 11 of the outer cylinder air vents 42 are all unified at the height h1. In addition, the heights to the upper surface of the annular portion 45 with respect to the upper surface 11a of the furnace bottom 11 are all unified at the height h2, and the height h2 to the upper surface of the annular portion 45 is measured and unified to the same value. Thus, the height h1 of the outer cylinder air vent 42 can be easily unified to the same value.

The second outer cylinder closing member 39 is formed in an annular flat plate shape in which an opening 39a is formed in a substantially central region. The outer diameter of the second outer cylinder closing member 39 is formed to be substantially the same as the outer diameter of the outer cylinder 36, and the lower end of the outer cylinder 36 and the outer end of the second outer cylinder closing member 39 are welded and fixed at the welding portion W7. It is done. The diameter of the opening 39a formed in the second outer cylinder closing member 39 is larger than the outer diameter of the inner cylinder 35, and the inner cylinder 35 is inserted through the inside of the opening 39a.

A gap β1 is formed between the opening 39a and the outer peripheral surface 35c of the inner cylinder 35. The length of the gap β1 is set in the range of 1/1000 to 1/50 of the length of the outer diameter d of the inner cylinder 35. That is, the gap β1 is set to satisfy the equation d / 1000 ≦ β1 ≦ d / 50. In the present embodiment, for example, it is set to 0.5 mm. Although the length of the gap β1 is not limited to 0.5 mm, it is necessary to make the total area of the outer cylinder air vents 42 formed in the outer cylinder 36 sufficiently smaller so that a large amount of air is not ejected from the gap β1. Therefore, the range of β1 ≦ 0.5 mm is more preferable. Further, the temperature of the inside of the furnace 5 is 800 to 900 ° C., as compared with the fact that the temperature of the inner cylinder 35 and the cylindrical portion 44 does not easily become high because the air flowing in the inner cylinder 35 is about 200 to 300 ° C. Therefore, the temperature of the outer cylinder 36 and the cylindrical portion 46 exposed in the furnace 5 becomes high. Therefore, when the furnace 5 is operated, the gap α1 between the outer peripheral surface 44a of the cylindrical portion 44 and the inner peripheral surface 46a of the cylindrical portion 46 tends to increase by about 0.1 mm due to the thermal expansion difference due to the temperature difference. Therefore, in the present embodiment, by setting the length of the gap β1 to be within 0.1 to 0.5 mm, the outer cylinder 36 is prevented from generating rattling even during operation of the furnace 5 be able to.

Next, the length of the diameter D of the cylindrical portion 44 will be described. In the present embodiment, the diameter D is set to, for example, approximately 20 mm. However, the diameter D is not limited to 20 mm, and may be 20 mm or less, or 20 mm or more.
The diameter D of the cylindrical portion 44 is preferably in the range of 1/10 to 1/2 times the outer diameter d of the inner cylinder 35. That is, the diameter D is set to satisfy the equation d / 10 ≦ D ≦ d / 2. Specifically, for example, when the length of the outer diameter d of the inner cylinder 35 is 80 mm, the length of the diameter D of the cylindrical portion 44 is preferably set within the range of 8 mm to 40 mm. By setting it in such a range, the central axial line of the inner cylinder 35 and the central axial line of the outer cylinder 36 can be surely positioned at substantially the same position.

Next, the height (length) H of the portion where the cylindrical portion 44 and the cylindrical portion 46 are engaged will be described. In detail, the height H means the length from the upper surface 43 a of the disc portion 43 to the upper end surface of the cylindrical portion 46. In the present embodiment, the height H is set to, for example, approximately 50 mm. However, height H is not limited to 50 mm, 50 mm or less may be sufficient, and 50 mm or more may be sufficient.
The height H is preferably in the range of not less than 1/2 and not more than 5 times the diameter D of the cylindrical portion 44. That is, the height H is set to satisfy the equation D / 2 ≦ H ≦ 5 · D. The height H is more preferably in the range of more than 1 to 5 times the length of the diameter D of the cylindrical portion 44. That is, it is further preferable to set the height H so as to satisfy the equation 1 · D <H ≦ 5 · D, and to make the cylindrical portion 44 longitudinally elongated in the vertical direction. Specifically, for example, when the diameter D of the cylindrical portion 44 is 20 mm, the height H is preferably set in the range of 10 mm to 100 mm. Moreover, it is more preferable to set it as more than 20 mm and 100 mm or less. By setting it in such a range, the central axis of the inner cylinder 35 and the central axis of the outer cylinder 36 can be surely positioned at substantially the same position, and the outer cylinder 36 can be replaced a plurality of times. (Details will be described later).

Next, the flow of air flowing in the air nozzle 12 according to the present embodiment will be described.
The air sent from the FDF 27 flows into the respective inner cylinders 35 substantially uniformly through the air box 29. The air flowing into the inner cylinder 35 flows upward as shown by the solid arrows in FIG. The air that has flowed upward is discharged from the inner cylinder air vent 41 into the space between the inner cylinder 35 and the outer cylinder 36 (that is, the inside of the outer cylinder 36). The air discharged to the inside of the outer cylinder 36 flows downward in the inside of the outer cylinder 36 in order to be closed by the annular portion 45. Most of the air that has flowed downward passes through the outer cylinder air vents 42 and is supplied to the fluidized bed inside the furnace 5. That is, of the air flowing downward through the inside of the outer cylinder 36, the air supplied to the fluidized bed inside the furnace 5 through the gap β1 is only a part.

Next, a method of replacing the outer cylinder 36 of the air nozzle 12 according to the present embodiment will be described with reference to FIG. Although three air nozzles are illustrated in FIG. 4, the air nozzle before replacing the outer cylinder, the air nozzle from which the outer cylinder has been removed, and the air nozzle after replacing the outer cylinder are shown sequentially from the left.
The cylindrical portion 44 and the cylindrical portion 46 are cut in a substantially horizontal direction by an electric metal saw or the like at a position lower than the welding portion W5 for welding and fixing the cylindrical portion 44 and the cylindrical portion 46, or lower than the welding portion W5. The welding fixed part is removed by scraping off to a position with a grinder etc. (removal step). At this time, the length A of the cylindrical portion 44 and the cylindrical portion 46 to be removed is, for example, about 5 mm to 10 mm in the present embodiment. The length A is equal to or slightly longer than the height S (see FIG. 3) required for welding and fixing the weld W5.

When the weld fixing portion is removed, the fixation between the cylindrical portion 44 and the cylindrical portion 46 is released. In the present embodiment, the welding fixing portion connecting the inner cylinder 35 and the outer cylinder 36 is only the welding portion W5, so the welding portion W5 is removed to fix the inner cylinder 35 and the outer cylinder 36. Is also released.

The cylindrical portion 44 is welded and fixed to the cylindrical portion 46 at the upper end. As a result, even if the welded portion W5 is removed, the cylindrical portion 44 remains longer than a predetermined length.
The predetermined length is a length by which the cylindrical portion 44 is accommodated inside the cylindrical portion 46 and the upper end portion of the cylindrical portion 44 and the upper end surface of the cylindrical portion 46 can be welded and fixed. Thereby, even if the cylindrical portion 44 removes the weld portion W5 with the cylindrical portion 46, the length in the vertical vertical direction of the cylindrical portion 44 remains equal to or greater than a predetermined length. Therefore, even after the cylindrical portion 46 is removed from the cylindrical portion 44, the cylindrical portion 46 'fixed to the replacement outer cylinder 36' can be attached to the cylindrical portion 44 again. Furthermore, if the length in the vertical vertical direction of the cylindrical portion 44 is sufficient, even if the rewelding fixing portion between the cylindrical portion 44 and the cylindrical portion 46 'is removed again, the vertical vertical direction of the cylindrical portion 44 If a length of not less than a predetermined length remains, the cylindrical portion 46 is removed from the cylindrical portion 44 a plurality of times, and the cylindrical portion 46 'of the replacement outer cylinder 36' It can be attached.
Here, although it is preferable that the replacement outer cylinder 36 'be newly manufactured, it may be removed once to repair a necessary portion depending on a damaged state.

Next, the outer cylinder 36 and the second outer cylinder closing member 39 fixed to the first outer cylinder closing member 38 where the fixing of the cylindrical portion 46 is released are moved upward and removed from the inner cylinder 35 (removal step).
Next, the replacement outer cylinder 36 ', the replacement first outer cylinder closing member 38' and the replacement second outer cylinder closing member 39 'are attached (attaching step). At this time, the horizontal position of the replacement outer cylinder 36 'is exchanged by attaching the cylindrical portion 46' of the first replacement outer cylinder closing member 38 'to engage with the remaining cylindrical portion 44. It is the same position as the position of the front outer cylinder 36 in the horizontal direction. Further, the lower surface of the annular portion 45 'of the first replacement outer cylinder closing member 38' is placed in contact with the upper surface 43a of the disc portion 43, whereby the vertical position of the replacement outer cylinder 36 'is before replacement. And the same position as the position of the outer cylinder 36 in the vertical direction. The length of the cylindrical portion 46 'of the replacement first outer cylinder closing member 38' is appropriately adjusted to be substantially the same as the length of the remaining cylindrical portion 44.
Next, the upper end portion of the cylindrical portion 44 and the upper end surface of the cylindrical portion 46 'of the replacement first outer cylinder closing member 38' are welded and fixed in the welding portion W5 '(fixing step).

According to the present embodiment, the following effects are achieved.
In the present embodiment, the cylindrical portion 44 and the cylindrical portion 46 are engaged in an intermediate fit or gap fit state, and more preferably engaged in a gap fit state close to the intermediate fit. Thereby, when attaching the outer cylinder 36 to the inner cylinder 35 fixed to the furnace bottom 11, the cylindrical portion 44 restricts the horizontal movement of the cylindrical portion 46, and an axis with respect to the cylindrical portion 44 of the cylindrical portion 46. The cylindrical portion 44 regulates the direction. Therefore, when attaching the outer cylinder 36 to the inner cylinder 35, the relative position between the inner cylinder 35 and the outer cylinder 36 in the horizontal direction and the axial direction aspect of the outer cylinder 36 with respect to the inner cylinder 35 can be easily specified relative positions. And axial orientation. Specifically, positioning can be performed so that the central axis of the inner cylinder 35 and the central axis of the outer cylinder 36 are at substantially the same position (a state of matching within a predetermined error).
The lower surface of the annular portion 45 is placed in contact with the upper surface 43 a of the disk portion 43 fixed to the inner cylinder 35. Thus, when the outer cylinder 36 is attached to the inner cylinder 35, the outer cylinder 36 can be disposed with reference to the inner cylinder 35. Therefore, the relative position between the inner cylinder 35 and the outer cylinder 36 in the vertical direction can be easily made to be a predetermined relative position. Since the inner cylinder 35 remains fixed to the furnace bottom 11, by setting the relative position between the inner cylinder 35 and the outer cylinder 36 in the vertical direction to a predetermined relative position, the reference portion of the outer cylinder 36 in the furnace 5 The height position with respect to the furnace bottom 11 can be made into a predetermined height position. Specifically, the heights h1 (see FIG. 4) of the plurality of air nozzles 12 provided in the furnace 5 from the top surface 11a of the furnace bottom 11 of the outer cylinder vent 42 are all the same height. Can. Further, this can be easily adjusted and confirmed by making all the heights h2 (see FIG. 4) from the top surface 11a of the furnace bottom 11 of the annular portion 45 which is easy to measure the same height.
By setting the relative position between the inner cylinder 35 and the outer cylinder 36 and the axial direction as described above, the fluidized bed in the furnace 5 can be uniformly fluidized.

Further, since the fluidizing material flows in the furnace 5, if the fluidizing material collides in the vicinity of the outer cylinder vent hole 42, the air nozzle 12 may be worn and reduced in thickness. Specifically, the outer cylinder 36 may be worn or thinned. When the outer cylinder 36 is worn or reduced in thickness, air is not suitably supplied from the outer cylinder 36 to the fluidized bed in the furnace 5, and a uniform fluidized bed can not be formed. If the uniform fluidized bed can not be formed, the combustion efficiency of the furnace 5 may be reduced. Therefore, it is necessary to inspect a large number of air nozzles 12 and repair a plurality of air nozzles 12. In repairing the air nozzle 12, in the present embodiment, the outer cylinder 36 can be replaced without removing the inner cylinder 35 from the furnace bottom 11 while the inner cylinder 35 is fixed to the furnace bottom 11.
When the air nozzle 12 is fixed to the furnace bottom 11, in order to form a uniform fluidized bed in the furnace 5, the longitudinal direction of the inner cylinder 35 is provided in the vertical direction, and the reference portion of the inner cylinder 35 ( Careful adjustment of the air nozzle 12 to the furnace bottom 11 so that the height h1 of the outer cylinder air vent 42 from the outer cylinder 36 is aligned by aligning the upper surface 43a) of the disk portion 43 at a predetermined height position with respect to the furnace bottom 11. Alignment work is required. In the present embodiment, when the outer cylinder 36 is replaced, the inner cylinder 35 is not removed from the furnace bottom 11, so the alignment work of the inner cylinder 35 with the furnace bottom 11 can be omitted. Also, when attaching the outer cylinder 36 to the inner cylinder 35 again, the cylindrical portion 44 can be attached so as to be inserted into the cylindrical portion 46, so that the relative position and the axial direction can be easily determined. It can be done.
Therefore, the replacement work of the outer cylinder 36 can be facilitated, and the time required for the replacement work of the outer cylinder 36 can be shortened. Therefore, the work load which arises at the time of repair work of air nozzle 12 can be eased.

The diameter D of the cylindrical portion 44 is preferably in the range of 1/10 to 1/2 times the outer diameter d of the inner cylinder 35, and the cylindrical portion 44 and the cylindrical portion 46 are in the engagement portion. The height H is preferably in the range of 1/2 to 5 times the length of the diameter D of the cylindrical portion 44, and is more than 1 time the length of the diameter D of the cylindrical portion 44. A range of twice or less is more preferable. In the present embodiment, for example, the diameter D is set to 20 mm, and the height H to 50 mm. Further, the length S required for welding and fixing the cylindrical portion 44 and the cylindrical portion 46 is set to, for example, 5 mm to 10 mm in the present embodiment. The length A of the fixed portion of the cylindrical portion 44 and the cylindrical portion 46 for removing and scraping off the welded fixed portion to release the fixed state between the inner cylinder 35 and the outer cylinder 36 is necessary for the welding and fixing. The height is equal to or slightly longer than the height S and is, for example, about 5 mm to 10 mm. For this reason, even after removing the cylindrical portion 44 a plurality of times, the height S necessary for welding and fixing remains on the cylindrical portion 44. As long as the height of the cylindrical portion 44 remains longer than the length S necessary for welding and fixing the cylindrical portion 44 and the cylindrical portion 46, the replacement outer cylinder 36 'can be attached. Therefore, the outer cylinder can be replaced a plurality of times without removing the inner cylinder 35.
Specifically, in the present embodiment, when the diameter D is set to 20 mm and the height H to 50 mm, for example, the length A to be removed is 5 mm, the length S necessary for welding and fixing is 5 mm, and the annular portion 45 For example, if the thickness of the outer cylinder is 10 mm,
(H: 50 mm-Ring thickness: 10 mm-Last exchange A: 5 mm-Last exchange S: 5 mm) / (A: 5 mm + S: 5 mm) + In the formula of one last exchange It can be represented four times.
Thus, the outer cylinder can be replaced a plurality of times without replacing the inner cylinder 35 by setting the height H so as to satisfy the following equation (1).
H ((X-1) · (A + S) + (ring portion 45 thickness + A + S) · · · (1)
However, A: length to be removed X: assumed number of replacements (when replacing the outer cylinder multiple times, it is an integer of 2 or more)
S: Length required for welding and fixing

When the inner cylinder 35 and the outer cylinder 36 are fixed by bolts or the like so that the outer cylinder 36 can be removed, for example, the fluid material flows in the furnace 5 and the temperature is high. The flow sand may get caught between them and the bolts may get stuck, which may make it difficult to remove the outer cylinder 36 from the inner cylinder 35. In this embodiment, since the inner cylinder 35 and the outer cylinder 36 are fixed by welding with the fixing portion limited to the upper end of the cylindrical portion 44 and the upper end surface of the cylindrical portion 46, the change in the fixing state hardly occurs. The fixing of the inner cylinder 35 and the outer cylinder 36 can be released by a determined method. Therefore, the working time required for the replacement work of the outer cylinder 36 can be shortened.

Second Embodiment
Subsequently, a second embodiment of the air nozzle according to the present invention will be described with reference to FIG. The air nozzle 52 according to the present embodiment differs from the first embodiment in the structure of the cylindrical portion. The same parts as those in the first embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted.
The cylindrical portion 53 according to the present embodiment integrally has an engaging portion 54 fixed to the disk portion 43 and engaged with the cylindrical portion 46, and a small diameter portion 55 extending upward from the upper end of the engaging portion 54. ing.

The outer peripheral surface 54 a of the engaging portion 54 of the cylindrical portion 53 is disposed along the inner peripheral surface 46 a of the cylindrical portion 46, and between the outer peripheral surface 54 a of the engaging portion 54 and the inner peripheral surface 46 a of the cylindrical portion 46. There is a slight gap α2 (not shown). That is, the engagement portion 54 and the cylindrical portion 46 are engaged in a state of intermediate fit or clearance fit, and more preferably in a state of clearance fit close to the intermediate fit (for example, the tolerance of the hole of the cylindrical portion 46 The area class is H9, and the tolerance area class of the axis of the engaging portion 54 is engaged at h9).

The small diameter portion 55 of the cylindrical portion 53 is set to have a smaller diameter than the engaging portion 54. A gap α3 is provided between the outer peripheral surface 55a of the small diameter portion 55 and the inner peripheral surface 46a of the cylindrical portion 46. The length in the horizontal direction of the gap α3 is set to be longer than the length in the horizontal direction of the gap α2. In the present embodiment, for example, the length in the horizontal direction is set to be 0.1 mm to 0.2 mm longer than α2. That is, the diameter D1 of the small diameter portion 55 is set smaller than the diameter D2 of the engaging portion 54 by about 0.1 mm to 0.2 mm.
That is, on the side closer to the disc portion 43 of the cylindrical portion 53, a gap α2 is provided as the engaging portion 54, and on the tip end side where welding fixation between the cylindrical portion 53 and the cylindrical portion 46 is performed, a gap longer than the gap α2. α3 is provided.

The vertical height H2 of the engaging portion 54 is preferably in the range of 1/2 to 2 times the length of the diameter D2 of the engaging portion 54. That is, the height H2 is set so as to satisfy the equation D2 / 2 ≦ H2 ≦ 2 · D2. Specifically, for example, when the length D2 of the engaging portion 54 is 20 mm, the height H2 is preferably set in the range of 10 mm to 40 mm. By setting it in such a range, the central axis of the inner cylinder 35 and the central axis of the outer cylinder 36 can be made to be substantially the same position with certainty, and replacement of the outer cylinder 36 is repeated several times. It becomes possible.

The following effects are achieved in the present embodiment.
In the present embodiment, in the small diameter portion 55 extending upward from the upper end of the engaging portion 54, the distance of the gap α3 between the outer peripheral surface 55a and the inner peripheral surface 46a of the cylindrical portion 46 is the same as that of the outer peripheral surface 54a of the engaging portion 54 It is longer than the distance of the gap α2 with the inner circumferential surface 46a of the portion 46. Thereby, even if deformation, damage or the like occurs in a part of the small diameter portion 55 having a diameter smaller than that of the engaging portion 54, the small diameter portion 55 and the inner circumferential surface 46a of the cylindrical portion 46 are difficult to contact The cylindrical portion 53 can be easily inserted into the cylindrical portion 46.
Therefore, when attaching the outer cylinder 36 to the inner cylinder 35, the cylindrical portion 53 can be easily inserted into the cylindrical portion 46 other than the engaging portion 54, and the outer cylinder 36 and the inner cylinder 35 When the outer cylinder 36 is removed from the inner cylinder 35, even if the small diameter portion 55 is deformed or damaged, it can be removed smoothly. Therefore, the management of components other than the engaging portion 54 can be simplified, which facilitates handling.

In the present embodiment, an example in which the engaging portion 54 is provided at the lower end of the cylindrical portion 53 has been described, but the position of the engaging portion is not limited to this. The engaging portion is provided at an intermediate position in the vertical direction of the cylindrical portion 53, the small diameter portion is provided so as to sandwich the engaging portion from above and below, and the small diameter portion provided near the disk portion 43 of the cylindrical portion 53 It may be easy to insert as far as 53.

Third Embodiment
Subsequently, a third embodiment of the air nozzle according to the present invention will be described with reference to FIG. In the air nozzle 62 according to the present embodiment, the shapes of the inner cylinder 63, the inner cylinder closing member 65, and the second outer cylinder closing member 66 are different from those in the first embodiment. The third embodiment is different from the first embodiment in that the third outer cylinder closing portion 67 is fixed to the inner cylinder. The same parts as those in the first embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted.

The inner cylinder 63 has a cylindrical main body portion 63 b and a first projecting portion 63 a protruding outward in the radial direction from the upper end portion of the main body portion 63 b. The first projecting portion 63 a is disposed in an annular shape along the outer peripheral direction of the inner cylinder 63. The projection length L of the first projection 63a is set to, for example, 15 mm to 20 mm.

The inner cylinder closing member 65 includes a cylindrical portion 65 d located inside the cylindrical portion 46, a disk portion 65 a placed on the upper end surface of the inner cylinder 63 and closing the upper opening of the inner cylinder 63, and an outer periphery of the disk portion 65 a A disk-shaped second projecting portion 65b protruding radially outward from the end and a projecting portion 65c extending downward from the lower surface of the disk portion 65a are integrally formed. The diameter of the disk portion 65 a is set to be substantially the same as the diameter of the main portion 63 b of the inner cylinder 63. The second projecting portion 65 b is disposed along the circumferential direction of the disc portion 65 a. Further, the diameter of the second protrusion 65 b is set to be substantially the same as the diameter of the first protrusion 63 a. The convex portion 65 c has a diameter substantially equal to the inner diameter of the inner cylinder 63, and is disposed inside the inner cylinder 63 by fitting, and the longitudinal central axis of the inner cylinder 63 and the longitudinal central axis of the inner cylinder closing member 65 Are almost identical.
The outer peripheral end of the first projecting portion 63a and the outer peripheral end of the second projecting portion 65b are fixed by welding at the welding portion W8.

The second outer cylinder closing member 66 is formed in an annular flat plate shape in which an opening 66a is formed in a substantially central region. The diameter of the opening 66a is set such that the inner cylinder 63 provided with the first protrusion 63a can pass therethrough. That is, the length of the gap β2 formed between the opening 66a and the outer peripheral surface of the inner cylinder 63 is larger than the projection length L of the first projection 63a.

The third outer cylinder closing portion 67 integrally has an annular closing portion 67a fixed to the outer circumferential surface of the inner cylinder 63 and a rising portion 67b rising upward from the outer circumferential end of the closing portion 67a. The third outer cylinder closing portion 67 is disposed on the upper surface of the closing portion 67a in a state in which the annular portion 45 of the first outer cylinder closing member 38 is placed in contact with the disc portion 65a of the inner cylinder closing member 64. The welding portion W9 is fixed to the inner cylinder 63 so that the cylinder closing member 66 is placed. The inner diameter of the rising portion 67 b is set larger than the outer diameter of the second outer cylinder closing member 66. A gap β3 is formed between the inner circumferential surface of the rising portion 67b and the outer circumferential surface of the second outer cylinder closing member 66. In the present embodiment, the length of the gap β3 is set to, for example, 0.5 mm. Although the length of the gap β3 is not limited to 0.5 mm, it is necessary to make the total area of the outer cylinder air vent 42 formed in the outer cylinder 36 sufficiently smaller so that a large amount of air is not jetted from β3. The range of β3 ≦ 0.5 mm is more preferable.

Next, a method of replacing the inner cylinder closing member 64 according to the present embodiment will be described with reference to FIG.
First, the outer cylinder 36 is removed from the inner cylinder 63. The method of removing the outer cylinder 36 is the same as that of the first embodiment, so the description will be omitted.

Next, the first projecting portion 63a and the second projecting portion 65b are substantially vertical with an electric metal saw or the like at a position radially inward of the welding portion W8 where the first projecting portion 63a and the second projecting portion 65b are welded and fixed. The welding fixation portion is removed by cutting in the surface direction or the welding fixation portion is scraped off with a grinder or the like. At this time, the length B of the first protrusion 63a and the second protrusion 65b to be removed is, for example, about 5 mm to 10 mm in the present embodiment. When the weld fixing portion is removed, the fixing between the first protrusion 63 a and the second protrusion 65 b is released. In the present embodiment, the welding fixing portion connecting the inner cylinder 63 and the inner cylinder closing member 65 is only the welding portion W8. Therefore, the inner cylinder 63 and the inner cylinder closing member are removed by removing the welding portion W8. Fixation with 65 is also released.
The first protrusion 63 a and the second protrusion 65 b are welded and fixed at the outer end, and the removal length B is shorter than the protrusion length L. Thereby, even if the welding portion W8 is removed, the first projecting portion 63a and the second projecting portion 65b remain by a predetermined length at which welding can be fixed again.

Next, the inner cylinder closing member 65 whose fixing has been released is moved upward and removed from the inner cylinder 35.
Next, the replacement inner cylinder closing member is attached. At this time, the replacement inner cylinder closing member is placed on the upper end surface of the inner cylinder 63 so that the convex portion 65 c is disposed and fitted inside the inner cylinder 63. Since the diameter of the convex portion 65c is substantially the same as the inner diameter of the inner cylinder 63, the convex portion 65c and the inner cylinder 63 engage with each other, restricting the horizontal movement of the replacement inner cylinder closing member, which is easy In addition, the horizontal position of the replacement inner cylinder closing member can be the same as the horizontal position of the inner cylinder closing member 65 before the replacement. Further, by placing the disc portion of the replacement inner cylinder closing member on the upper end surface of the inner cylinder 63, the position of the replacement inner cylinder closing member in the vertical direction is the position of the inner cylinder closing member in the vertical direction before the replacement It can be in the same position. Therefore, the replacement inner cylinder closing member can be easily attached. The length of the second protrusion of the replacement inner cylinder closing member is appropriately adjusted to be substantially the same as the length of the remaining first protrusion.

Next, the outer end of the first protrusion 63a and the outer end of the second protrusion of the replacement inner cylinder closing member are fixed by welding.
Next, the outer cylinder 36 is attached to the inner cylinder 63. The method of removing the outer cylinder 36 is the same as that of the first embodiment, so the description will be omitted.

The following effects are achieved in the present embodiment.
The inner cylinder closing member 65 (in particular, the cylindrical portion 65d) may be damaged or deformed due to the influence of the furnace 5 or reattachment with the replacement outer cylinder.
In the present embodiment, even when the inner cylinder closing member 65 is damaged or the like, the inner cylinder closing member 65 may be removed from the inner cylinder 63 and removed without removing the inner cylinder 35 fixed to the furnace bottom 11. it can. Therefore, it is possible to reduce the work load that occurs when the inner cylinder closing member 65 is repaired.

Further, in the present embodiment, the first projection 63 a is set to have a projection length L of 15 mm to 20 mm, and is removed to release the fixation between the inner cylinder 63 and the inner cylinder closing member 65. The length B of the second protrusion 65b is 5 mm to 10 mm. Therefore, even if the first protrusion 63a is removed multiple times, the first protrusion 63a remains. Therefore, the inner cylinder closing member 65 can be replaced a plurality of times without replacing the inner cylinder 63.

In addition, the tip of the cylindrical portion 44 is removed in order to replace it with a replacement outer cylinder, and the cylindrical portion 44 is fixed to the furnace bottom 11 even when the length becomes an irremovable length. Without removing the inner cylinder 63, the inner cylinder closing member 65 can be replaced including the cylindrical portion by replacement. Therefore, it is possible to increase the number of times of replacement which can replace the outer cylinder 36 without removing the inner cylinder 63.

The present invention is not limited to the invention according to the above-described embodiments, and appropriate modifications can be made without departing from the scope of the invention.
For example, although the above-mentioned each embodiment explained the example which applies the present invention to circulating fluidized bed boiler 2, the present invention may be applied to a fluid bed boiler (BFB: Bubbling Fluidized Bed).
In each of the above embodiments, the shape of the cylindrical portion is cylindrical, and the shape of the cylindrical portion is cylindrical. However, the cylindrical portion and the cylindrical portion may be any shape that engages with each other. The shape is not limited to the shapes of the above embodiments. The cylindrical portion may be a column extending in the vertical direction, and may be, for example, a prism. Further, the shape of the cylindrical portion may be any shape that engages with the cylindrical portion, and may be, for example, a square tube.
In the above embodiments, the outer cylinder, the first outer cylinder closing member, and the second outer cylinder closing member are conceptually divided and described, but the outer cylinder (that is, the cylindrical portion) and the first outer cylinder are described. It may be considered that the outer cylinder is formed by the closing member and the second outer cylinder closing member.

1 Power generation system 2 Circulating fluidized bed boiler (boiler)
Reference Signs List 3 steam turbine 4 generator 5 furnace 11 furnace bottom 12 air nozzle 13 cyclone 29 air box 35 inner cylinder 36 outer cylinder 37 outer cylinder 37 inner cylinder closing member (second connection portion)
38 1st outer cylinder closing member (1st connection part)
39 second outer cylinder closing member 43 disk portion 44 cylindrical portion (column portion)
45 annular part 46 cylindrical part (cylindrical part)
52 air nozzle 53 cylindrical portion 54 engagement portion 55 small diameter portion 62 air nozzle 63 inner cylinder 63a first projecting portion 65 inner cylinder closing member 65b second projecting portion 66 second outer cylinder closing member 67 third outer cylinder closing member W1 ~ W9 weld

Claims (12)

An air nozzle for fluidizing a fluid material in the furnace by supplying a gas into the furnace,
A cylindrical inner cylinder fixed to the furnace bottom of the furnace, extending vertically upward from the furnace bottom, and supplied with gas;
A cylindrical outer cylinder in which the inner cylinder is disposed and which supplies the gas discharged from the inner cylinder into the furnace;
A first connection portion having a cylindrical portion extending vertically upward, and fixed to an upper end portion of the outer cylinder;
And a second connection portion fixed to the upper end portion of the inner cylinder, and having a pillar portion extending vertically upward.
The column portion is housed inside the cylinder portion such that the outer peripheral surface of the column portion is along the inner peripheral surface of the cylinder portion,
The air nozzle by which the upper end part of the said pillar part and the said cylinder part are welding-fixed. The air nozzle according to claim 1, wherein the column portion and the cylinder portion are engaged in a state of an intermediate fit or a gap fit. The air nozzle according to claim 1 or 2, wherein the lower end surface of the cylindrical portion is disposed on the upper end surface of the inner cylinder. The pillar portion has an engaging portion whose outer peripheral surface is along the inner peripheral surface of the cylindrical portion, and a small diameter portion whose diameter is smaller than that of the engaging portion and which extends vertically upward from the upper end of the engaging portion The air nozzle according to any one of claims 1 to 3, comprising. The second connection portion has a disk portion provided at the lower end of the column portion,
The air nozzle according to any one of claims 1 to 4, wherein the lower surface of the disc portion is placed on the upper end of the inner cylinder. The inner cylinder has a cylindrical main body portion, and a first projecting portion that protrudes outward in the radial direction from the upper end portion of the main body portion,
The second connection portion has a second protrusion protruding radially outward from the outer peripheral end of the disc portion,
The diameter of the disc portion is substantially the same as the diameter of the main body portion, and
The air according to claim 5, wherein the inner cylinder and the second connection portion are fixed by welding and fixing an outer end portion of the first projecting portion and an outer end portion of the second projecting portion. nozzle. An outer cylinder of an air nozzle that fluidizes a fluid material in the furnace by supplying a gas discharged from an inner cylinder disposed inside the furnace into the furnace,
A tubular main body,
And a second connection portion fixed to the upper end portion of the main body portion.
The cylindrical portion accommodates a vertically extending upward columnar portion of the first connection portion fixed to the upper end portion of the inner cylinder in such a manner that the outer peripheral surface of the columnar portion is along the inner peripheral surface of the cylindrical portion And
The cylindrical portion is an outer cylinder of an air nozzle welded and fixed to the upper end portion of the pillar portion. The length in the vertical direction of the region in which the column portion is accommodated in the cylindrical portion is at least 1/2 times and at most 5 times the radial length of the column portion. The outer cylinder of the air nozzle according to claim 7, which is set. The length in the vertical direction of the region in which the column portion is accommodated in the cylindrical portion is set to a range longer than one time and five times or less the length in the radial direction of the column portion The outer cylinder of the air nozzle according to claim 7. A furnace in which a fluid material is caused to flow internally by the air nozzle according to any one of claims 1 to 6 or the air nozzle provided with an outer cylinder according to any one of claims 7 to 9;
A flue through which the combustion gas generated by the furnace flows;
A heat exchanger provided in the flue to generate steam by the heat of the combustion gas. The boiler according to claim 10,
A steam turbine driven by steam generated by the boiler;
A generator that generates electric power by the driving force of the steam turbine. An air nozzle for fluidizing a fluid material in the furnace by supplying a gas into the furnace,
A cylindrical inner cylinder fixed to the furnace bottom of the furnace, extending vertically upward from the furnace bottom, and supplied with gas;
A cylindrical outer cylinder in which the inner cylinder is disposed and which supplies the gas discharged from the inner cylinder into the furnace;
A first connection portion having a cylindrical portion extending vertically upward, and fixed to an upper end portion of the outer cylinder;
And a second connection portion fixed to the upper end portion of the inner cylinder, and having a pillar portion extending vertically upward.
The column portion is housed inside the cylinder portion such that the outer peripheral surface of the column portion is along the inner peripheral surface of the cylinder portion,
It is the exchange method of the outer cylinder of the air nozzle by which the upper end part of the above-mentioned pillar part and the above-mentioned cylinder part are welding fixed,
A removal step of removing a portion fixed by welding;
Removing the outer cylinder from the inner cylinder after the removing step;
Attaching the replacement outer cylinder to the inner cylinder after the removing step;
A fixing step of welding and fixing an upper end portion of the pillar portion and the cylindrical portion after the mounting step; and a method of replacing an outer cylinder of an air nozzle.

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