JPS61142186A - Method of repairing bottom of storage tank - 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 [Field of Industrial Application] This invention relates to a method for repairing the bottom of a storage tank, and more particularly to a method for replacing annular plate and repairing the foundation.

[Prior Art] In a storage tank such as an oil tank, the annular plate, which receives the most load from the side plates, is susceptible to corrosion, and therefore it becomes necessary to replace the annular plate. In addition, when replacing the annular board, we spread heavy oil on river sand or mountain sand to replace the foundation of the conventional storage tank with asphalt mortar or asphalt sand.
The foundation is often modified to a thickness of approximately m + a.

Conventionally, there is a so-called "total jack-up method" for the bottom s'n shudder method such as replacing the annular board or modifying the foundation.This whole jack-up method is a method in which the side board and the annular board are cut out and stored. A large number of jacks are installed all around the outer circumference of the tank, and brackets that engage with each of these jacks are fixed on the outer peripheral surface of the side plate, and the side plate is jacked up to replace the annual plate. be.

Another conventional annular board replacement method is generally called the "piece method."

In this construction method, as shown in Fig. 4, after cutting out the lower part of the side panel 3 and separating the side panel 3 and the annular board 2,
Replace the required annular plate 2, and then drive a liner material 5 such as a gold plate between the side plate 3 and the annular plate 2, fix the support piece 6 to the side plate 3 to support the load of the side plate 3, and complete the entire annular plate. 2. After the replacement is completed, the liner material 5 is removed, the lower part of the support piece 6 is cut little by little, and the side plate 3 is gradually lowered onto the annular plate 2.

[Problems to be Solved by the Invention] The two conventional construction methods described above have various problems as shown below.

In other words, in the overall jack-up method, it is necessary to use a large number of expensive jacks, it is necessary to create a jack base etc. around the tank to install the jacks, and furthermore, when lifting the side plate, the side plate may be deformed. In order to prevent the tank from tilting or tilting, the side panels must be reinforced or supported, and many people must be stationed around the tank, which lengthens the construction period and increases construction costs. Furthermore, in the overall Schatzki-up construction method, it is common to lift the side plate to about 500 to 800 m+o, so the joints with the piping around the tank have to be cut, resulting in a lack of stability.
Safety measures against earthquakes and strong winds are required.

On the other hand, although the B-Sue method is an inexpensive construction method, it requires replacing the existing annular board with a new annular board immediately after removing it, making it difficult to modify the foundation directly below the side board, for example, due to uneven settlement. be. In addition, support
Because the pieces were cut one by one and the side plates were lowered, excessive stress was generated around the last support piece.
There is also a risk of tank deformation. Furthermore, since the lower part of the lateral root is cut out, the height of the storage tank is lowered, thus reducing the storage efficiency and requiring a request for structural modification. In addition, since the mounting positions of nozzles, manholes, etc. will also change, the joints with piping outside the tank must be changed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a storage tank bottom repair method that eliminates these conventional problems.

[Means for solving the problem 1 The method for repairing the bottom of a storage tank according to the first invention includes the step of cutting off the annular plate and the side plate all around the tank, and the step of cutting off the annular plate and the side plate over the entire circumference of the tank, and the step of cutting off the annular plate and the side plate at a predetermined height on the inner surface of the side plate. The storage tank is divided into multiple zones in the circumferential direction, and jacks are sequentially placed between the annular plate and the brackets in each zone. After lifting the side plate and inserting the liner material between the side plate and the annular plate, the jacks are removed and moved to the next area, and the liner material on the annular plate that needs to be replaced is removed and this annular plate is replaced with a new one. The step of replacing the new annular plate with the new annular plate and inserting liner material between the new annular plate and the side plate, and
a step of welding the plates etc. together, a step of sequentially arranging a jack between the annular plate and the bracket in each area, removing the liner material and lowering the side plate with the jack, and a step of welding the annular plate and the side plate together. It consists of a welding step.

According to the second invention, a method for repairing the bottom of a storage tank includes supporting the side plate with the liner material in the same manner as described above, and then repairing the annular plates and the bottom plate other than the annular plate in the portion holding the liner material. The stage of removing and correcting the foundation, laying the bottom plate, removing the liner material for each section equivalent to one new annual board and the part of the annual board that supports this liner material, and laying a new annual board. a step of inserting a liner material between the annular plate and the side plate; a step of welding the new annular plate and the bottom plate;
It consists of the steps of sequentially arranging a jack between the new annular plate and the bracket for each area, removing the liner material and lowering the side plate using the jack, and welding the new annular plate and the side plate. ing.

Other objects, features, and advantages of the first and second inventions will become apparent from the detailed description below in conjunction with the accompanying drawings.

[Embodiment 1] Figures 1.2 of the drawings show an embodiment of a storage tank bottom repair method, particularly an annular plate replacement method, according to the first invention. In the annular plate replacement method of this embodiment, first, the fillet weld between the side plate 3 and the annular plate 2 is removed by tweezing, the side plate 3 and the annular plate 2 are cut away, and then a predetermined part is attached to the inner surface of the side plate 3. A plurality of brackets 10 are fixed by welding at pitches of 3 to 4 m in the circumferential direction in terms of height. Next, this storage tank 1 is
It is divided into a plurality of areas for each circumference of 0 to 50 +a, and in one of the areas, the 7-piece 11 is placed between the annular plate 2 and the bracket 10 (Fig. 1), and the 7-piece 11 is activated. and lift the side plate 3 to the specified height. This lifting height is preferably about 50 to 70 ma+ so that butt welding and inspection of the annular plates 2 immediately below the side plates 3 can be performed. A liner material 12 such as a metal plate is placed between the side plate 3 lifted by the jack 11 and the annular plate 2.
is inserted, and the side plate 3 is supported at that height. After the support of the side plate 3 is completed, the jack 11 is removed and moved to another area, and the side plate 3 is lifted and supported in the same manner as described above. This operation is sequentially repeated in all areas of the storage tank 1, and the entire side plate 3 is supported by the liner material 12 (FIG. 2). Here, cut off the annular plate 2 that needs to be replaced from the adjacent annular plate 2, remove the liner material 12, pull out the annular plate 2, insert a new annular plate 2, and replace the liner material 12 with the annular plate 2 again. It is inserted between the plate 2 and the side plate 3. Annular plate 2
If you want to replace everything, repeat this operation one by one. After the replacement work is completed, the annular plates 2 are welded together and this welding is inspected. To lower the side plate 3 onto the annular plate 2, first place the jack 11 between the bracket 10 and the annular plate 2 in one area, and then lower the liner material 12 in the same way as the reverse of the previously described jacking up of the side plate 3. After that, the jack 11 is moved to another area, and this operation is repeated to lower the entire side plate 3 onto the annular plate 2. In this way, the bracket 10 is removed, the annular plate 2 and the side plate 3 are welded together, and the annular plate is inspected after welding.
The replacement of board 2 is completed.

When modifying the foundation when replacing the annual plate,
An embodiment of the storage tank bottom repair method according to the second invention is shown in FIGS. 1.2 and 3.
As shown in the figure. In this method, the side plate 3 is lifted to a predetermined height and supported by the liner material 12 in the same procedure as the annular replacement method described above. Here, as shown in FIG. 3, leave an annular plate (hereinafter referred to as liner material support plate 2) large enough to support the liner material 12, and move the annular plate 2 up to the bottom plate. Cut and remove the base VI! 4. Make appropriate modifications. At this time,
The bottom base of the liner material support plate 2! 4, even if any one set of the liner material support plate 2' and the liner material 12 thereon is removed, the side plate 3 will still be supported by the other liner material support plate 2' and the liner material 12. Taking into account the fact that 4 Shift it up. After the foundation correction is completed, if necessary, replace the bottom plate with a new one and lay the bottom plate on the foundation 4. Next, liner material 1 is applied in an area equivalent to one sheet of new annular board 2.
2 and liner material support plate 2, and install a new annular
Insert plate 2 and reinstall liner material 12 into a new annular
It is inserted between the plate 2 and the side plate 3 to support the side plate 3. After repeating this operation and completing the installation of the new annular plate 2, the bottom plate and the annular plate 2 are welded and inspected. Thereafter, in the same manner as in the method for installing the annular plate according to the first invention, the side plate 3 is jacked in each area and lowered onto the annular plate 2, and necessary treatments such as welding are performed to remove the annular plate. Board replacement and base! Complete the fix.

[Effects of the Invention] As described above, according to the first and second inventions, since the side plate is lifted or lowered partially and continuously over a certain width using a jack, the ffM tank can be lifted or lowered at one point. Stress is not concentrated and costs can be reduced by reducing the number of jacks used. In addition, since the amount of lifting of the side plate is small, stability is high, and the jacks and brackets only need to be small, making it easy to install and remove them. Since the tank capacity does not change, there is no need to cut or modify the joints of piping around the tank or apply for structural changes. Furthermore, since the annular board is used as the jack base or liner base, construction can be carried out without modifying the foundation around the tank, which has the effect of greatly improving economical efficiency and construction efficiency.

[Brief explanation of the drawing]

Fig. 1.2 shows an embodiment of the method for repairing the bottom of a storage tank according to the invention of No. 1 and fIIJ2, Fig. 1 is a partial sectional view of the storage tank showing jacking up the side plate, and Fig. 2 3 is a schematic explanatory view showing the side plate supported by liner material, FIG. 3 is a schematic explanatory view showing the removal of the annular plate and the bottom plate in an embodiment of the bottom repair method according to the second invention, and FIG. 1 is a partial sectional view of a storage tank showing a conventional annular plate replacement method. In the figure,
1: Storage tank, 2: Annular plate, 2' Niliner material support plate, 3: Side plate, 4: Foundation, 5.12 Niliner material,
6: Support piece, lO bracket, jack on 1. Patent applicant: Toyo Kanetsu Co., Ltd. Figure 1 Figure 4

Claims (1)

[Claims] 1. Cutting off the annular plate and side plate over the entire circumference of the tank, and fixing a plurality of brackets at appropriate intervals to the inner surface of the side plate at a predetermined height over the entire circumference of the tank. the storage tank is circumferentially divided into a plurality of areas, a jack is sequentially placed between the annular plate and the bracket in each area, the side plate is lifted up by the jack, and the liner is placed between the side plate and the annular plate. After inserting the material, the jack is removed and moved to the next area, the liner material on the annular plate that needs to be replaced is removed and the annular plate is replaced with a new annular plate, and the liner material is removed between the new annular plate and the side plate. a step of welding together the annular plates, etc., a step of sequentially arranging a jack between the annular plate and the bracket for each area, removing the liner material and lowering the side plate with the jack. A storage tank bottom repair method comprising the steps of: and welding an annular plate and a side plate. 2. Cutting off the annular plate and side plate around the entire circumference of the tank, fixing a plurality of brackets at appropriate intervals to the inner surface of the side plate at a predetermined height, and cutting the storage tank. Divide the area into multiple areas in the circumferential direction, place a jack between the annular plate and the bracket in each area, lift the side plate with the jack, insert a liner material between the side plate and the annular plate, and then The steps include removing the jack and moving it to the next area, removing the annular plates other than the annular plate supporting the liner material and the bottom plate to correct the foundation, and laying the bottom plate and removing the part equivalent to one new annular plate. At each step, the liner material and the annular plate supporting the liner material are removed, a new annular plate is installed, the liner material is inserted between the new annular plate and the side plate, and the new annular plate and the bottom plate are welded together. a step of sequentially arranging a jack between the new annular plate and the bracket for each area, removing the liner material and lowering the side plate with the jack, and a step of welding the new annular plate and the side plate. A method for repairing the bottom of a storage tank. 3. In the step of modifying the foundation, in order to modify the foundation of the lower part of the annular plate in the part that supports the liner material, remove the liner material, move the annular board, and reinsert the liner material for each annular board. 3. The method for repairing the bottom of a storage tank according to claim 2, wherein the method is performed sequentially.