JPS6145742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for repairing the bottom of a tank, and more particularly to a method for replacing an annular plate that constitutes the bottom of a tank. This is the purpose.

Generally, a storage tank for petroleum, etc. has a bottom that consists of a bottom plate and an annular plate placed along the periphery of the bottom plate, and a side plate of the tank is placed upright on top of the annular plate. This type of storage tank is formed by covering it with a roof plate, but this type of storage tank is easily corroded because it is installed outdoors and exposed to wind and rain. This corrosion is most noticeable at the bottom of the tank, more specifically at the annular plate.

Conventional methods for replacing annular plates generally include lifting the entire tank (jack-up method) and cutting off a portion of the lower end of the tank side plate (piece method). The jack-up method involves cutting off the annular plate that makes up the bottom of the tank and the side plates that are welded to the annular plate, then lifting the entire tank, and then attaching the new annular plate to the new annular plate while the tank is lifted. This method involves replacing the tank with a new annular plate, lowering the tank, and welding the lower end of the same tank to the new annular plate. There are problems in terms of economy and safety, such as the large-scale construction work involved in lifting the roof, which is also dangerous.

The piece construction method, as shown in Figure 5, involves cutting the lower end of the side plate to an appropriate width (approximately 30 to 50 mm) without lifting the storage tank, while the entire tank is fixed to the inside of the side plate. After replacing the annular plate, cut off the lower end of the support piece in small increments to lower the tank, and remove the side plate and new annular plate. This is a method of replacing the plate by welding the abutting part of the plate, and with this piece construction method, cutting out the support piece is troublesome and it is difficult to lower the tank smoothly. However, there are problems in terms of workability and safety, such as being dangerous.

The present invention is an attempt to improve the conventional situation in view of the above-mentioned conventional situation, and is characterized by improving the economical efficiency in addition to workability and safety.

That is, the gist of the present invention is to cut out and remove the lower edge of the side plate and the annular plate following the lower edge of the same side plate with a certain opening size, and to remove the removed part of the annular plate. The foundation was repaired and a new annual plate was installed in the same area, and the joint between the new annual plate and the bottom plate, and the joint between the replaced new annual plate adjacent to the new annual plate. During the welding process, a support piece is installed on the inner surface of the side plate in correspondence with the installation position of the new annual plate, and a journal jack is interposed between the support piece and the new annual plate to attach the side plate. After repeating the supporting process and each of the above processes for the entire circumferential surface of the side plate, lower the side plate using a journal jack and weld the lower edge of the same side plate to the contact surface of the new annular plate. The structure is such that the annular plate is replaced during each stroke.

Specific embodiments of the present invention will be described below with reference to illustrative drawings. In Figure 1, storage tank A is the foundation B.
This is a drawing showing a state in which the device is installed on top, and in the same drawing, 1 is a bottom plate, 2 is an annular plate, and 3 is a side plate. Also, 4 is a concrete foundation,
5 is oil sand, 6 is concrete ring, 7 is
indicate the asphalt baked-in layer, respectively.

However, in the state where the storage tank A is installed on the foundation B as described above, the bottom of the tank A, that is, the annular plate 2 and a part of the bottom plate 1 (hereinafter referred to as "annual plate 2 etc.") ”
When replacing the tank A, first the mounting plates 8 are attached by welding at regular intervals along the outer circumferential surface of the side plate 3, and the reinforcing ring 9 is attached in a circumferential manner so as to surround the tank A through each mounting plate 8. A wedge 10 is driven between the reinforcing ring 9 and each mounting plate 8.

Further, the side plate 3 and the annular plate 2 are divided into an appropriate number of blocks with a constant frontage dimension L. In a state where the side plate 3 and the annular plate 2 are divided into an appropriate number of blocks with a constant frontage dimension L, the side plate 3 has an arbitrary height dimension for any one of the blocks. At the same time, the annular plate 2 and the like to be connected to the same side plate 3 are cut out with an appropriate depth dimension.
A portion of the cut-out side plate 3 and a portion of the annular plate 2 and the like are removed, and foundation correction is performed on the removed portion of the annular plate 2 and the like. Specifically, while the level and slope of the bottom plate 1 are measured, new oil sand from which the oil sand 5 has been removed is laid.

After the above-mentioned foundation corrections have been made, a new annular plate 2 will be installed in place of the removed part of the annular plate 2, etc., and the joint between the annular plate 2 and the bottom plate 1 will be welded. be done.

On the back side (inner peripheral surface) of the side plate 3, a support piece 11 is attached by welding in correspondence with the installation position of the new annular plate 2, etc., and the support piece 11 and the new annular plate 2, etc. A journal jack 12 is installed between them.

After the annular plate 2 is replaced in this way for a given block, the annular plate 2 is replaced in the adjacent section in the same manner as above. The following replacement work is repeated for each compartment in turn. In each replacement work, the joint between the new annular plate 2 and the bottom plate 1 is welded, and the new annular plate 2 and the same annular plate are welded together. The joint of the replaced new annual plate 2 adjacent to the Euler plate 2 is welded.

FIG. 4 is a drawing showing a state in which the annular plate 2 and the like have been replaced in all sections of the side plate 3, and the side plate 3 is cut away from the bottom, in other words, the side plate 3 is cut away from the bottom. is supported by each journal jack 12. With the side plate 3 supported by each of the journal jacks 12 in this manner, the lower end of the side plate 3 is beveled and finished with a grinder, and then each of the journal jacks 12 is sequentially lowered. By doing so, the side plate 3 is lowered. and side plate 3
When the lower end of the mounting plate 8 is lowered to the position where it contacts the new annular plate 2,
After adjusting the perfect circle of the side plate 3 by driving the wedge 10 interposed between the reinforcing ring 9 attached by the same mounting plate 8..., the lower end of the side plate 3 and the new annular The plates 2 are welded together and integrated through the welding. After the lower end of the side plate 3 and the new annular plate 2 are integrated, the journal jack 12, the support piece 11, the mounting plates 8... and the reinforcing ring 9 are removed, respectively. Others 13 indicate guide pieces.

The present invention is constructed as described above, and includes:
As mentioned above, the lower end of the side plate, annual plate, etc. were cut out and removed for each section, and replaced with a new annual plate, while the side plate was supported by journal jacks via support pieces. Therefore, the lower end of the same side plate is kept in a cut-off state, and after replacing it with a new annual plate, etc., the side plate is lowered via the journal jack. It has now become possible to perform the descending work safely and quickly, and as a result, it has become possible to significantly improve safety, workability, and economic efficiency.

That is, in the present invention, by lowering the side plate via the journal jack, the side plate can be lowered smoothly, the side plate can be stopped at any position, and the animation can be stopped. The final dimensions of the Euler plate can be easily adjusted, improving work efficiency, and the weight of the side plate can be distributed evenly to each part without locally concentrated stress on specific parts of the side plate. It has become possible to lower the objects in a dispersed state, increasing safety.
In other words, in the conventional piece construction method, after replacing the annular plate as described above, the tank is lowered by cutting off the lower end of the support piece in small increments, so the tank can be lowered smoothly. It is difficult to lower the tank, and stress is locally concentrated on a specific part of the side plate.However, in the present invention, the amount of descent of the tank can be slightly reduced by the amount of rotation of the journal jack. In addition to being adjustable, it has become possible to prevent local stress concentration by allowing multiple workers to simultaneously rotate the journal jack by a certain amount. Furthermore, according to the present invention, the annular plate can be replaced by lowering the tank without lifting it, which makes the replacement work easier. As a result, it has become possible to reuse jigs such as journal jacks, thereby increasing their economical effects.

In addition, in the present invention, the above-mentioned journal jack is interposed between the new annual plate and a support piece attached to the inner surface of the side plate, so that the load applied to the journal jack is supported by the new annual plate. By doing so, it became possible to prevent the new annular plate from being distorted by this load, and workability was improved in this respect as well. That is, as mentioned above, welding (fillet welding) is performed between the lower end of the side plate and the new annular plate, and in this way the new annular plate is held down by the journal jacks. By performing welding work in this condition, we have been able to prevent the new annular plate from deforming due to welding.

[Brief explanation of the drawing]

Figure 1 is a side view of the tank showing its condition before repair;
Figure 2 is a front view of the tank showing the lower end of the side plate and the annular plate cut out, and Figure 3 shows the new annular plate installed and the side plate supported by journal jacks. FIG. 4 is a front view of the tank, FIG. 4 is a sectional view of the same side, and FIG. 5 is a side sectional view of the tank showing the conventional construction method. A...Tank, B...Foundation, 1...Bottom plate, 2...
... Annular plate, 3 ... Side plate, 4 ... Concrete foundation, 5 ... Oil sand, 6 ... Concrete ring, 7 ... Asphalt baking layer, 8 ... Mounting plate, 9 ... Reinforcement ring, 10 …
... Wedge, 11... Support piece, 12... Journal jack, 13... Guide piece.

Claims (1)

[Claims] 1 The process of cutting and removing the lower edge of the side plate and the annual plate following the lower edge of the same side plate with a certain frontage dimension, and making foundation corrections to the removed part of the annual plate and removing the same part. The process of laying a new annual plate on the floor, welding the joint between the new annual plate and the bottom plate, and the joint of the replaced new annual plate adjacent to the new annual plate, and the process of welding the inner part of the side plate. A process of installing a support piece on the side surface in correspondence with the installation position of the new annual plate, and interposing a journal jack between the support piece and the new annual plate to support the side plate, and each process described above. The annular plate in the tank consists of repeating the process for the entire circumference of the side plate, then lowering the side plate via a journal jack, and welding the lower edge of the same side plate to the contact surface of the new annular plate. Replacement method.