JPH0112906B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temporary scaffold in a boiler furnace, and particularly to a temporary scaffold suitable for construction of a large circulation boiler such as a thermal power plant.

The furnace of a circulation boiler installed in a thermal power plant or the like has a rectangular parallelepiped-shaped surrounding area. Most of these peripheral surfaces have a double structure consisting of a water tube wall inside the furnace and a casing outside the furnace, and the gap between the water tube wall and the casing is filled with a fireproof heat insulating material. The entire furnace has a suspended structure to absorb the thermal expansion, which reaches several tens of centimeters, during operation. That is, the boiler furnace is suspended from a steel frame provided around its outer periphery, so that the elongation of the furnace due to thermal expansion escapes downward. When installing a boiler furnace, first, a steel frame is installed, and then the water pipe walls are hung from the ceiling beams of the steel frame, and the water pipe walls are installed from the top to the bottom. On-site installation of water pipe walls mainly involves welding, which requires a large amount of man-hours and involves dangerous work at heights. Once the installation of the water pipe wall around the entire circumference has been completed, we will conduct a water pressure test on the water pipe wall.
Inspect welding points.

After the water pressure test is completed, an airtightness test will be conducted inside the furnace, which is surrounded by water pipe walls. After the airtightness test is completed, install fireproof insulation and casing from the outside of the water pipe wall. In addition, in boilers with other structures, the water pipe walls are not airtight, but the fireproof insulation material and the casing are made airtight. In this case, after completing the installation of the casing, conduct an airtightness test inside the furnace.

Since the inside of the furnace is hollow, when installing the water pipe wall, a temporary scaffold for the installation work is installed on the side wall of the furnace (this side wall does not exist at the beginning of construction).
By sequentially attaching the water pipe walls, the water pipe walls themselves form part of the side wall. ). Temporary scaffolding is used to set water pipe walls that have been delivered in pieces to the construction site at the specified mounting positions, scaffolding to weld water pipe walls together, and scaffolding for hydraulic pressure tests of water pipe walls. used as. This temporary scaffolding is installed to match the total height and width of the furnace, so it is quite large for large circulation boilers, reaching approximately 50m in height and 20m in length on each side. Therefore, when constructing a boiler furnace, not only does the quality of the plan for the temporary scaffolding affect the workability of the main construction, but also the cost and number of days required to assemble and dismantle the temporary scaffolding are also important issues. Become.

Conventionally, the so-called assembly method has been used for temporary scaffolding in the boiler furnace, in which pipe scaffolding or steel unit scaffolding is assembled from the bottom (for example, above ground) to the top. The reasons why the assembling method was commonly used were: firstly, it was the most common method for temporary scaffolding, secondly, it was the most familiar method based on past results, and the construction technology was already established. This is due to the fact that no other effective alternative method was found for 3. However, this assembly method had the following problems. Firstly, it takes many days to assemble and dismantle the boiler, which has a large impact on the boiler construction process.
The number of man-hours required for assembly and disassembly is enormous;
Thirdly, the cost of doing so would be enormous, and the third problem was the assembly and
There is a lot of work to be done at height during disassembly, which is not desirable for work safety.Fourthly, because it is assembled from below, the bottom of the furnace (in coal-fired boilers, this bottom becomes the ash hopper section consisting of refractory material and a group of water pipes,
In oil or gas-fired boilers, the bottom is often made of refractory material and a group of water tubes. )
For example, it is difficult to adjust the construction process.

The fourth problem is particularly important, and when temporary scaffolding is assembled from the ground, the scaffolding becomes an obstacle, making it virtually impossible to construct the bottom of the furnace. For this reason, it is common practice to construct the bottom of the furnace first and then assemble the scaffolding from this bottom. However, as mentioned above, in a boiler with a suspended structure, this method results in having to construct the bottom section first, which is unnatural as a means of constructing a furnace. Extra steps are required.

The purpose of the present invention is to solve the disadvantages of the above-mentioned prior art temporary scaffolding of the assembly method, and to provide a temporary scaffolding in a boiler furnace that is easy to assemble and disassemble, and is compatible with the construction process of a boiler furnace having a suspended structure. It's about providing a foothold.

To achieve this objective, the temporary scaffold of the present invention is entirely suspended from a position above the boiler structure, and its structure connects a plurality of horizontal bars and vertical bars with slides, It is characterized by scaffolding boards spanning between horizontal bars adjacent to each other.

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows the schematic configuration of a circulation boiler. In the figure, a ceiling beam 12 is provided at the top of a steel frame 10, and the entire boiler is suspended from this ceiling beam 12. The boiler mainly consists of a shed 14, a furnace 16 surrounded by a two-dot chain line in the figure, and an area 18. The shed 14 is equipped with a brackish water separator, and the area 18 is equipped with a superheater and a reheating device. Containers and economizers will be placed. Further, in the lower part 20 of the area 18, there is an air preheater, a blower, and a wind duct that connects these.
A flue etc. will be placed. The temporary scaffolding according to the present invention is usually installed around the four sides of the furnace 16 along the side walls thereof, and the entire structure is directly or indirectly suspended from the ceiling beam 12 by hanging members 22. As shown in FIG. 2, this temporary scaffolding has a structure in which a horizontal rod 24 and a vertical rod 26 are connected to a sliding joint, and a scaffold board 28 is spanned between horizontal rods adjacent to each other in a horizontal position. The details of the connection mechanism are shown in FIG.
At both ends of the horizontal bar 24, there are two tsuba 30,
32 is provided, and a connecting plate 36 having a keyhole 34 is provided at both ends of the vertical bar 26. By inserting this connecting plate 36 between the flanges 30 and 32 of the horizontal rod 24, the horizontal rod 24 and the vertical rod 26 are connected to each other in a sliding joint. As shown in FIG. 2, a horizontal rigid member 38 is interposed to connect the hanging member 22 and each vertical bar 26. As shown in FIG. This horizontal rigid member adjusts the positional relationship between the hanging member 22 and the vertical rod 26, and serves to maintain the levelness of the scaffold. In order to ensure the levelness of the horizontal rigid member, for example, a turnbuckle may be provided on the suspension member 22 for adjustment. Each vertical bar 26 and each horizontal bar 2
4 are manufactured with the same shape and dimensions, so even if the scaffold is assembled by connecting them,
The horizontality of the scaffold board 28 is maintained. If it is assumed that tensile loads will only act on some of the vertical bars due to manufacturing errors in the dimensions of each member that makes up the scaffold, for example, turnbuckles may also be provided on the vertical bars to ensure that the scaffold is horizontal. What is necessary is to be able to adjust the degree and load distribution.

FIG. 4 shows a state in which the scaffold according to this embodiment is assembled in multiple stages and in two directions. When assembling the scaffolding, first assemble scaffold A shown on the left side of the figure, and then assemble scaffold B shown on the right side. In addition to the horizontal rigid member 38 at the top of each of Scaffold A and Scaffold B, an intermediate horizontal rigid member 40 is provided at an intermediate position between every multiple stages, and after the assembly of both Scaffolds A and B is completed, these The horizontal rigid member 38 and the intermediate horizontal rigid member 40 are interconnected. If necessary, braces 42 and 44 are provided across these horizontal rigid members to strengthen the connection between both scaffolds. By performing the above assembly around the four peripheries of the boiler furnace, the assembly of the temporary scaffolding is completed. Since stairs are required to go up and down each step of the scaffold, at least one of the four scaffolds provided on each side has a vertical bar 26 and a horizontal bar as shown in Figure 5. 24 and the skeleton connected to 2
Provided in parallel in rows. And on one side of the frame,
A stair scaffold 46 is provided, and an intermediate scaffold board 48 is spanned over the gap between both frames.

The scaffold according to this embodiment has a structure that can be assembled step by step from above to below, and disassembled step by step from below to above. Therefore, when assembling, each scaffolding member to be attached to an upper position is assembled at a position on the ground where workability is good, and while this scaffolding is lifted one stage at a time, connecting the scaffolding members of the subsequent stage at the same position on the ground. Just go. At the time of dismantling, contrary to the above, each scaffold member can be dismantled from below to above while suspending the entire scaffold, also at the ground position. Therefore, there is less need to work at heights when assembling and dismantling scaffolding, and the work can be done safely and easily. Furthermore, since the entire scaffold is suspended directly or indirectly from the steel frame of the boiler, the scaffold can be assembled regardless of the construction status of the bottom of the boiler furnace. Therefore, it is suitable for the construction process of a boiler furnace, which is constructed from the top to the bottom. The construction status of the furnace is closely related to the assembly and disassembly of this scaffolding.
First, when assembling, it is extremely preferable that the construction of the water pipe wall located on the top surface of the furnace is completed. This ceiling water pipe wall partitions the furnace 16 and the shed 14, as shown in FIG. If scaffolding is assembled before construction of this ceiling water pipe wall 15,
A hanging member 22 for hanging a scaffold is attached to the ceiling water pipe wall 1
It becomes an obstacle during the construction of 5. That is, since several dozen hanging members 22 are hung as necessary, it is difficult to construct the ceiling water pipe wall 15 while avoiding the positions of these hanging members. In particular, modern boilers often use a method of welding a panel-like structure in which several dozen water pipes are arranged in parallel and integrated, and when using such a panel-like water pipe wall, it is necessary to Their presence makes the construction of ceiling water pipe walls virtually impossible. When assembling the scaffolding after the construction of the ceiling water pipe wall 15 is completed, the position of the hanging member 22 can be selected to avoid the position where the water pipe extends. When the ceiling surface is composed of a panel-shaped water pipe wall, a cutout hole is provided in the fin portion of the panel where the water pipe is not located, and the hanging member 15 is passed through the cutout hole. The cutout holes may be provided at any stage, either when the panels are manufactured in-house at a factory or when construction of the ceiling water pipe wall is completed on-site. In other words, the present invention replaces the suspended scaffolding, which was conventionally inconceivable due to the presence of ceiling water pipe walls, by sewing between the ceiling water pipes.
It can be said that the idea of penetrating the hanging member has made it more technically viable. Furthermore, when disassembling the scaffold, it is extremely preferable that the individual members constituting the scaffold can be disassembled within predetermined dimensions. In other words, the scaffolding inside the furnace needs to be in place at least until the airtightness test of the furnace is completed. At this stage, the furnace has a nearly sealed structure, and the only opening is a manhole located at the bottom of the furnace. Therefore, it is preferable that each member constituting the scaffold has a shape and size that allows it to be carried out from this manhole after being dismantled. Otherwise, it will be necessary to provide special openings for the removal of the scaffolding elements during or after the construction of the furnace. The scaffolding according to the above example is
As shown in FIG. 2, a horizontal bar 24, a vertical bar 2
6. The scaffolding board 28 is the basic structure, and since these members have a straight and simple shape, they can be easily carried out from the manhole. From the above point of view, it is preferable that the horizontal rigid member 38 and the intermediate horizontal rigid member 40 are also separable by a structure such as bolt tightening.

As described above, the temporary scaffolding inside a boiler furnace according to the present invention is easy to assemble and dismantle, and is compatible with the construction process of a suspended structure of a boiler furnace. It is suitable for

[Brief explanation of drawings]

FIG. 1 is a side view showing a schematic configuration when the temporary scaffolding according to the present invention is applied to a circulation boiler, and FIG. 2 is a perspective view showing the basic configuration of the temporary scaffolding according to the present invention.
FIG. 3 is an exploded perspective view for explaining the connection mechanism between the horizontal rod and the vertical rod according to the present invention, FIG. 4 is a partial perspective view showing the temporary scaffold according to the present invention assembled in two directions, and FIG. The figure is a partial perspective view illustrating the structure of the stair scaffolding according to the present invention. 10... Steel frame, 12... Sky beam, 16... Furnace, 22... Hanging member, 24... Horizontal bar, 26...
... Vertical rod, 28 ... Scaffolding board, 38 ... Horizontal rigid member, 40 ... Intermediate horizontal rigid member.

Claims (1)

[Scope of Claims] 1. Temporary scaffolding installed vertically in multiple steps along the side walls around the four sides of the boiler furnace, which is suspended by hanging members from the ceiling beams around the four sides of the boiler, and A horizontal rigid member whose both end surfaces are connected to each other and serves as a scaffold for the top layer; two or more pairs of vertical bars removably connected to the horizontal rigid member; and the pairs of vertical rods having flanged protrusions at both ends. It is composed of a horizontal rod removably spanned between vertical rods, and a second layer of scaffolding boards removably bridged between the horizontal rods, and the third and subsequent layers of scaffolding are constructed in the same way as the second layer. Temporary scaffolding inside a boiler furnace, characterized in that it is formed from vertical rods, horizontal rods, and scaffolding boards, and the vertical rods are detachably connected to the horizontal rods on the upper layer. 2. According to claim 1, the scaffolds are provided around the four peripheries of the boiler furnace and are interconnected, and a step scaffold is provided on at least one side of the scaffold. Temporary scaffolding inside the boiler furnace described. 3 The scaffolding provided around the four peripheries of the boiler furnace has horizontal rigid members at one or more positions at the same height of the scaffolding on each side, and these horizontal rigid members are interconnected. Temporary scaffolding in a boiler furnace according to claim 2, characterized in that: