JPS5980867A - Assembling construction of storage tank due to wide scaffold - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for assembling storage tanks using wide scaffolding.

The cylindrical side plate of the vertical cylindrical storage tank is made of many rectangular steel plates,
That is, the shell segments are stacked one by one by welding like stacking ridge tiles, and automatic welding is often used for this welding these days. In the construction process of the storage tank mentioned above, the shell segments are mounted on the tower, temporarily assembled,
In order to carry out various tasks such as welding, preparatory welding, finishing of welds, inspection, attachment of accessories, and painting, a large number of workers used temporary scaffolding to reach high places one by one and engage in assembly work. Become. By the way, the temporary scaffolding that has been used for a long time is
Its effective width is about 60 to 89 crn, which is narrower than the automatic welding machine width of 1.2 m, and therefore tends to impede the running operation of the welding machine. Therefore, instead of using wide scaffolding, which traditionally requires high temporary construction costs,
The measures described below are adopted. In other words, ■ bend the handrail stanchion and set it to a width that allows the automatic welding machine to pass through, or ■ form the handrail stanchion so that it can be folded to ensure a space for the welding machine to pass through, or Remove, etc. If the above-mentioned measures are taken, all the manual work that should or can be done simultaneously with automatic welding will be impossible due to the lack of handrails or scaffolding, so the work will be carried out in the next process or later. As a result of the above-mentioned measures, the above-mentioned measures contradict the purpose of improving efficiency, even though one of the reasons why automatic welding machines were originally adopted was to improve work efficiency.

In order to solve the problems of the conventional measures, a construction method for assembling a wind girder scaffold for storage tanks has been proposed as shown in Japanese Patent Publication No. 51-48884. Although this construction method does not include the concept of widening the scaffolding to the extent that it does not interfere with the running of the automatic welding machine, it is intended to reduce temporary scaffolding costs and reduce costs by shortening the construction period. By using the wind girder, which is originally a permanent attachment to a storage tank, as temporary scaffolding for tank construction, (1) there is no need for temporary scaffolding materials, and (2) there is no need to carry in and remove the scaffolding materials. (3) As the scaffolding is moved and placed on the upper stage according to the progress of assembling the side panels, the scaffolding can be completed and permanently fixed to the predetermined position of the side panels, so assembly and disassembly of the scaffolding can be omitted.

However, as disadvantages, (1) two brackets (upper and lower) are required, (21) When moving the scaffold, it is necessary to arrange and engage another bracket at a higher place above the unattached scaffold, (3) ) If the wind girder blocks are simply placed on the brackets as scaffolding materials, there is a risk of them falling off during transfer, so in order to prevent this, the blocks are connected to each other with fasteners called geta, and the inner ends of the wind girder are It is required that the (R machined surface) be assembled so that it is in close contact with the outer surface of the side plate, (4)' Therefore, scaffolding using a wind girder must be installed on the outer surface of the tank, and (5) the wind girder The width is determined in proportion to the product of the square of the tank diameter and the height, and in general, it is narrower than the width of the automatic welding machine and the handrail tends to obstruct the movement of the welding machine. However, due to the cross-sectional shape of the wind girder with 7 lunges at its outer end and the correlation with the point mentioned in (4) above, it is not possible to expand the width of the scaffolding. Due to the relationship between the hanging pieces and the temporary assembly jig for mounting the side plate on the outer surface of the side plate, the paint base coat was stained over a wide area, and the painting required a lot of curing after the jig was removed, resulting in a delay in construction. (8) Since the center of gravity of the wind girder is close to the outer end, the required strength and member dimensions of the support bracket become large, making it uneconomical.
(9) As the process progresses, each time the scaffolding is moved to the upper level, the fasteners called geta must be released or tightened. Because of this need, the wind girder is installed on the upper surface of the wind girder, that is, on the walking surface, which is said to be undesirable from a safety standpoint as it becomes an obstacle to walking.

This invention was made in view of the current situation, and is a tank assembly method that facilitates the temporary construction of wide scaffolding that does not impede the running of an automatic welding machine, and that reduces the cost and construction period of temporary scaffolding. This is what we are trying to provide.

Next, if this invention is explained with drawings, the first and second
And in Figure 6, a bracket 2 is constructed with sufficient width to support a scaffold board that is wider than the machine width of an automatic welding machine (not shown), and is made of three shaped steel members with sufficient strength. At the same time, two or four wind girders 1 each having a protruding hook-shaped outer end flange and an inverted U-shaped hook 6 fixed to the seven lunges are attached to the ground at each end. The brackets are welded to each other, and the brackets are fixed to the lower surface of the connecting girder at appropriate intervals by welding. At this time, the hook 6 becomes a flange part of the outer end 7 of the girder, and a stanchion 6 is provided upright on the other side (inner end) of the girder, and a friction lug 8 is provided at the lower side of the bracket. A plurality of scaffolding blocks 10 are constructed in this manner by protruding. In addition, a plurality of hanging metal fittings 9 for hoisting the scaffolding block are welded to appropriate locations on the top of the outer end 7 langes of the girder. If the width of the scaffold is less than the width of the scaffold, use a regular scaffold board and fix it to the bracket 2 with a rubber band to prevent it from falling off. A locking piece 7 shall be welded in advance to the inner surface of the hook 6 so that the free end of the hook 6 can be inserted from above and tightened with the sheet pile 5.After preparing the various setups υ described above, first After the first stage side plate 4 is erected and fixed around the entire circumference of the tank, the scaffold block is lifted by a crane truck using its binocular fittings 9, and the hook 6 of the scaffold block is attached to the side plate hooking piece 7. Insert it so that it stands on its own, and do this around the entire circumference to form a work scaffold with a series of scaffold blocks.Next, use the scaffold to erect and fix the side plate of the next upper stage, and then repeat as above. Then, the scaffolding block 10 is moved upward by a crane to form the next stage of work scaffolding, and this process is repeated to suspend the scaffolding block above the ground after the uppermost side plate is erected, and then dismantle it. , the wind girder 1 is lifted and fixed in a predetermined position again.

Therefore, according to the present invention, the required number of scaffold blocks to constitute the work scaffold is only one level of the side plate, which saves on materials, and when relocating the scaffold, new brackets can be installed at a high place on the upper level where there is no scaffolding yet. Not only does it require no installation work, it also improves safety.Since the brackets are welded to the wind girder, the scaffolding blocks are structurally strong, and the locking pieces are perfectly secured, reducing the risk of falling accidents during transfers. Since this does not occur, there is no need to connect the blocks to each other and there is no need to attach geta, and it also eliminates the hassle of tightening and releasing the geta each time the scaffolding is moved, reducing construction costs and construction time. In addition to eliminating the need for fixing the metal fittings that make up the girder to the girder, removing it, and finishing it afterwards, the safety of walking is improved by eliminating the use of geta as an obstacle when walking on scaffolding. Therefore, the scaffolding by the wind girder can be attached to the inner surface of the tank, so the width of the scaffolding can be easily expanded, and the side plate mounting jig and scaffolding hanging pieces can be attached to the inner surface of the tank, so the job primer on the outer surface of the tank will not be damaged. Therefore, the repainting area is reduced, which reduces the construction cost and construction period.It is also less affected by wind, improving work safety.Furthermore, the center of gravity of the entire scaffold is closer to the side plate, which reduces the strength of the bracket members. As mentioned above, the width of the scaffolding can be widened with a minimum amount of materials, so there is no problem with the automatic welding machine running, and other work can be carried out at the same time as automatic welding. Improving efficiency and
This improves work efficiency by relieving the psychological pressure peculiar to working at heights, and the wide scaffolding makes it easier for workers carrying materials and tools to pass each other, improving work efficiency. This invention has many advantages, such as being able to expand to provide sufficient airflow, making it possible to perform various tasks efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial plan view showing an embodiment of the present invention, and FIGS.
It is an enlarged arrow view. 1... Wind guard, 2... Bracket, 6...
・Stangeon, 4...Side board, 5...Sheet pile, 6...
・Hook, 7...Latching piece, 8...Friction lug, 9...
・Binocular metal fittings, 10...Scaffolding block. Agent Patent Attorney Sanro Kimura

Claims (1)

[Claims] After the side plate of the first stage of the tank is erected and fixed around the entire circumference, the scaffolding block is lifted by a crane truck, and the wind girder end face of the scaffold block is attached to the latch piece fixed in advance on the inner surface of the side plate. Insert the U-shaped hook and make the scaffolding block stand on its own as the friction lug at the end of the bracket on the lower surface of the wind girder comes into contact with the side plate, and do this around the entire inner circumference of the side plate so that the scaffold block can be attached to the continuous frame of the scaffolding block. Construct a work scaffold, then use the scaffold to stack and erect the next stage side board, make the work scaffold independent on the next stage side board in the same process, and then erect the top side board in the same manner. An assembly method for storage tanks using wide scaffolding.