JP2875590B2 - Scaffold for inspection in boiler furnace - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a scaffold for inspection in a boiler furnace, and particularly to a scaffold for inspection suitable for a furnace of a large-sized boiler for power generation.

[Conventional technology]

The boiler for power generation is regularly inspected by the Electricity Law to check the boiler tube for corrosion. This periodic inspection is performed by stopping the operation of the boiler and constructing a scaffold in the furnace of the boiler.

Many conventional scaffolds, like architectural scaffolds, consist of vertical columns, braces that reinforce these columns, horizontal members fixed to columns, and scaffold plates fixed to these horizontal members. (Hereinafter, this scaffold will be referred to as an assembled scaffold). All components of the assembled scaffold (posts, braces,
In addition to horizontal materials and scaffolding boards, handrails, cloths, roots,
(Including stairs, ties, joints, etc.) are carried into the furnace through manholes provided at the bottom of the furnace and assembled in the furnace. When assembling the scaffold, first, the foundation of the scaffold is formed in the furnace at the bottom of the furnace (curing the bottom of the furnace). This foundation must be made extremely robust because it carries the full load of the scaffold. When the foundation is completed, each stage of the scaffold is sequentially assembled from the first floor to the top floor.

Furthermore, what is referred to as jack-up scaffolds have recently been gradually used. In the case of this scaffold, a jack is placed on the foundation at the hearth, and a scaffold stage on the top floor is first assembled on this jack to jack up. Then, the scaffold stage on the lower floor is assembled and jacked up, and this is sequentially repeated to construct a scaffold.

[Problems to be solved by the invention]

In the case of the above-mentioned scaffolding type and gap-up type scaffolding, all parts constituting the scaffolding must be carried into the furnace from the manhole at the bottom of the furnace. Also, all components must be assembled in a furnace. As a result, it takes a very long time to load and assemble the parts.

Furthermore, the work of assembling the scaffold cannot be started until the working environment (particularly the temperature) in the furnace is adjusted.
Further, unless the entire scaffold is completed, inspection work inside the furnace cannot be performed.

Therefore, it takes a long time to assemble and disassemble the scaffold,
Most of the period for boiler tube inspection is scaffolding and dismantling. At present, with the increase in power demand, it is desired to reduce the time required for stopping the boiler at the time of periodic inspection, and particularly to reduce the time required for assembling and dismantling the scaffold for furnace inspection.

In addition to requiring a large amount of work to carry in and assemble the scaffold components, this foundation also requires a large amount of work because it is necessary to create a solid foundation that supports the full load of the scaffold. Thus, conventional scaffolds have high labor costs.

Furthermore, a column member and a horizontal member are indispensable to support the scaffold plate, and since the entire scaffold is a structure, a reinforcing bracing is required. In addition, a large amount of binding metal is required to connect the column members, the horizontal members, and the braces. Therefore,
The number of parts is large and the cost of the scaffold itself is high.

Furthermore, jack-up scaffolds are more costly because they require a controller, jack, motor, and the like.

Accordingly, an object of the present invention is to provide a low-cost inspection scaffold in a boiler furnace which can be easily assembled and disassembled in a relatively short time and has a small number of parts.

[Means for Solving the Problems] The object is to insert a large number of crosspieces inserted into the furnace from the outside of the furnace wall of the furnace through a through hole in the furnace wall and fixed to the furnace wall or an external support member, This is achieved by providing a scaffold plate held on a brace in the furnace. Here, the external support member means a reinforcing member attached to the outer surface of the furnace wall to suppress deformation of the furnace wall, or a boiler frame provided around the furnace wall.

In this case, the furnace wall of the furnace is substantially composed of a large number of boiler tubes, and this boiler tube is curved to form a through hole between the boiler tubes, and the arm is fixed to a holder welded to the boiler tube. It is desirable. Further, it is desirable that a fall prevention member is attached to the arm bar in the furnace.

[Action]

An inspection scaffold in a boiler furnace according to the present invention comprises inserting a brace from the outside of the furnace through a through hole in the furnace wall into the furnace, and fixing it to the furnace wall or an external support member, and mounting the scaffold plate in the furnace. It is built by putting it on a cross.

〔Example〕

Next, the present invention will be described in detail based on the embodiment shown in the drawings.

FIG. 1 shows a part of a furnace 1 of a radiation boiler for power generation and a scaffold 2 for inspection according to an embodiment of the present invention built in the furnace.
Is shown. In order to make the figure easier to see, the furnace 1
Shows only a part of the furnace wall, and other parts (for example, burners) are omitted. Further, scaffold 2 is shown with only two scaffold stages 2a, 2b.

The furnace 1 has a substantially rectangular shape in horizontal section, and its fire wall is substantially composed of densely arranged boiler tubes 3. The boiler tube 3 forms a strength member of the furnace wall, is suspended from a boiler frame at an upper end (not shown), and is connected to a header 4 at a lower end. The outside of the boiler tube 3 is covered with a heat insulator 5, which is further covered with a casing 6. This casing 6
Does not form the strength member of the furnace wall, but is merely an exterior material (coating material).

The scaffold 2 is constructed in the furnace. In the figure, two scaffolding stages 2a and 2b are constructed on the inner surfaces of the two furnace walls, respectively.
It is constructed on the inner surface of all furnace walls as in a and 2b. The scaffold stages 2a and 2b each include a horizontal arm 7, a scaffold plate 8 placed on the arm 7, and a fall prevention member 9 attached to the arm 7.

As shown in FIGS. 2 and 3, the arm brace 7 is inserted into the furnace from the outside of the furnace wall through a through hole formed in the furnace wall, and is fixed. FIG. 2 is an enlarged sectional view showing a state in which the arm bar 7 is inserted and fixed, and FIG. 3 is a right side view of FIG. Two boiler tubes 3a and 3b are used to form a through hole for the furnace wall.
It is bent near the insertion point. That is, as shown in FIG. 2, the boiler tube 3 is first bent toward the outside of the furnace wall (to the left in FIG. 2), and
It is bent laterally (to the left and right in FIG. 3) as shown. A holder 10 for fixing and holding the arm 7 is welded to an outer surface of the boiler tube 3 in a range outside the curved portion of the boiler tube 3. The holder 10 has a central tubular portion 10a, a flange-like portion 10b provided at one end of the tubular portion 10a, a rectangular plate-like portion 10c provided at the other end of the tubular portion 10a, and a plate-like portion 10c. , Which are welded to a plurality of boiler tubes 3 (in the example shown, are welded to six boiler tubes 3 as shown in FIG. 2). ). The flange-like portion 7a of the inserted arm bar 7 is fixed to the flange-like portion 10b of the holder 10 with bolts and nuts 11. A gap between the portions 10c and 10d of the holder 10 and the curved portion of the boiler tube 3 is filled with a castable refractory material 12.

The above-mentioned scaffold plate 8 is mounted on a brace 7 inserted into the furnace, as shown in FIG. In this case, the scaffold plate 8 may be simply placed on the arm arm 7 or the scaffold plate 8 and the arm arm 7 may be connected. Further, the scaffold plates 8 may be connected to each other.

The fall prevention member 9 is movably attached to the tip of the arm 7 as shown in FIG. This fall prevention member 9 is inserted into the furnace together with the arm 7 through a through hole in the furnace wall, and the tip hook 9a is hooked to the ring 9b of the other arm 7 as shown in FIG. Assembled. Like the handrail, the fall prevention member 9 serves to prevent a fall of the worker and guide the worker, and does not connect the arms 7 to reinforce the arms 7.

The inspection scaffold 2 in the boiler furnace having the above structure is assembled as follows. After the operation of the boiler furnace 1 is stopped, first, a sealing plug (not shown) inserted in the through hole of the furnace wall (inserted into the through hole instead of the arm bar 7 to close the through hole, and fixed to the holder 10) Is removed, and the arm 7 is inserted from the outside of the furnace together with the fall prevention member 9, and the arm 7 is fixed to the holder 10 by bolts and nuts 11. The insertion and fixing of the arm bar 7 is performed from a safe place outside the furnace. Even if heat remains in the furnace, the work of attaching the arm bar 7 can be performed. Next, after the temperature in the furnace 1 has been lowered and the working environment has been set, the scaffold plate 8 is carried in from a manhole (not shown) provided at the bottom of the furnace, the arms 7 are mounted, and the fall prevention member 9 is moved to the above-mentioned position. Assemble.

The inspection scaffold of the present invention is, as described above, a foundation, a pillar,
Since there is no need for bracing, staking, ties, joints, etc., the structure is simple and the cost is low.

Furthermore, since only the scaffold 8 is carried into the furnace from the manhole at the bottom of the furnace, the amount of work carried in is small. Further, since there is no need to provide a foundation in the furnace and the number of parts to be assembled in the furnace is small, the operation in the furnace is simple, and since the assembly is performed by relying on the fixed arms 7, the operation in the furnace is safe. is there.

Furthermore, while the temperature in the furnace is still high, the work of assembling the scaffold (the work of attaching the arms 7) can be started (conventionally, it has been necessary to wait about one day until the boiler cools down).
Furthermore, once a scaffold is completed on one of the four furnace inner surfaces, inspection of the furnace inner surface can be started, and there is no need to wait until all the furnace inner surfaces have been completed (until the entire scaffold is completed). .

In this way, the number of parts is small, the loading and assembling work is simple, and the assembling and inspection work can be started quickly, so that the number of days required for scaffolding construction and inspection, and the number of days for stopping the boiler are reduced. . this is,
This is very desirable in the current situation where power demand is tight.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, it is possible to change the shape of the holder and the mounting structure of the arm to the holder. Furthermore, without attaching the arm bar to the holder, an external support member, for example, a reinforcing member (for example, a back stay) attached to the outer surface of the furnace wall to suppress deformation of the furnace wall, or a boiler frame provided around the furnace wall is used. May be attached. Further, a stage may be provided between the upper and lower scaffold stages. In this stage, the inside of the scaffold plate (furnace center side)
Mounted diagonally to the brace (so the brace to attach the stairs is formed longer than the others). Further, the fall prevention member may be formed separately from the arm, without being inserted through the through hole in the furnace wall, and may be carried into the furnace from the manhole and attached to the arm. Further, the fall prevention member may have another shape.

〔The invention's effect〕

The inspection scaffold in the boiler furnace according to the present invention has a simple structure and a low cost because the number of parts is small. Furthermore, since the work for loading into the furnace and the work for assembling in the furnace are easy, and the construction and inspection work can be started quickly, the number of days required for scaffold construction and the number of days required for inspection, and thus the number of days for stopping the boiler, are reduced. Is shortened.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a boiler furnace having a scaffold according to an embodiment of the present invention, FIG. 2 is an enlarged vertical sectional view of a part where a brace is attached to a furnace wall, and FIG. 3 is a right side view of FIG. FIG. 4 is an enlarged perspective view of the fall prevention member. 1 ... furnace, 2 ... scaffold for inspection, 3 ... boiler tube (furnace wall), 7 ... arm bar, 8 ... scaffold plate, 9 ... fall prevention member, 10 ... holder

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E04G 1/36

Claims (3)

(57) [Claims] A plurality of crosspieces inserted into the furnace from the outside of the furnace wall through a through hole in the furnace wall and fixed to the furnace wall or an external support member, and held by the crosspieces in the furnace. A scaffold for inspection in a boiler furnace, comprising: a scaffold plate; 2. A furnace wall of a furnace is substantially composed of a large number of boiler tubes, and the boiler tubes are curved to form through holes between the boiler tubes, and the arms are fixed to a holder welded to the boiler tubes. The scaffold for inspection in a boiler furnace according to claim 1, characterized in that: 3. The scaffold for inspection in a boiler furnace according to claim 1, wherein a fall prevention member is attached to a brace in the furnace.