JPS6254708B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention provides the following features when completely or partially replacing the annular plate or bottom plate of a tank.
This invention relates to a new construction method for safely and economically advantageous replacement of annular plates or bottom plates in a short period of time without applying unbalanced loads to tank side plates.

2. Description of the Related Art Conventionally, a jack-up method has been used to replace the annual plate or bottom plate of a storage tank for petroleum, etc.

However, with this construction method, it is necessary to install a large number of jacks around the tank at as small and even intervals as possible in order to prevent tank deformation and uneven loads on the side plates due to jack ups. For this reason, it is necessary to install a cradle or stand for each jack, and the construction method becomes complicated, such as attaching the bracket necessary for jacking up to the tank side plate, which increases the number of man-hours and takes a long time. It is normal for construction costs to increase.

Subsequently, in order to simplify the above-mentioned construction method and improve construction efficiency, the lower part of the tank side plate was cut into a certain strip width to provide an opening, and the corresponding existing annular plate was inserted through the opening. A method was devised to take it out after cutting, lay a new annual plate in that position, and then support between the installed plate and the end of the side plate skirt at the opening (American Petroleum Institute, 3rd edition, published in 1972). Guide for Inspection of Refining Equipment p43-46
), and it is well known that it is already in practical use, as is the jack-up method. Compared to the above-mentioned jack up method, this method does not require a large amount of machinery and equipment, and it also simplifies construction when considering construction safety and the ability to prevent unbalanced loads and buckling of the tank. However, the following difficulties have been pointed out in terms of construction.

For example, in the above construction method, after replacing the old and new annular plates through the openings (band-shaped) provided at the bottom of the side panels, support is provided between the new plates and the side panel skirts, but this will not work when the intended replacement work is completed. , when grounding the tank, the support member must be grounded while being cut simultaneously and evenly under strict control at every predetermined minute dimension from its lower end, and the support member provided between the openings; Although it is strongly welded to the side skirt part and supports the vertical load of the tank well, it is not possible to shift the tank due to fluctuations in the horizontal load caused by wind or earthquakes during long-term construction. This is not necessarily a good idea when considering load, buckling, etc.

Here, the present inventors have attempted to solve this problem by giving priority consideration to the above points, and have also found that the lower part of the side plate of tanks of this type, especially medium-sized (capacity 20,000 Kl) or larger, is usually made of high-tensile steel (JIS G3115: SPV, When welding other steel materials to the side plate, it is necessary to preheat the welded part and ^at the same time post-heat the welded part. Since it is necessary to prevent cracking and ensure the quality of welded parts, it is preferable to add other parts to the side plates, taking into account the fact that it is optimal from the viewpoint of strength and quality control to have no such welded parts. This method has been devised to replace the annual plate or bottom plate safely and economically in a short period of time by eliminating the need for welding steel materials.

An embodiment of the present invention will be described below with reference to the drawings in which the same parts are denoted by the same reference numerals.

In the figure, 1 is a new annual plate (described later) installed at the lower end of the notch 3 of the tank side plate 2.
It forms the same horizontal plane as the bottom plate 12. The cutout portion 3 is formed by cutting the lower part of the upper side plate 2 in the circumferential direction based on the horizontal surface of the existing annular plate 1' provided at the lower part of the side plate 2, and cutting it manually or with an automatic cutting machine or the like in each predetermined section. This is a band-shaped part cut out to an even width, the width of which is usually about 30 mm based on the base mentioned above, and is obtained by accurately marking the cutting line in advance around the entire circumference of the tank.

As shown in Figure 3, the cutting length is a constant length in the circumferential direction, but it is not uniform depending on the tank type, structure, capacity, etc. Depending on the tank, this notch length may be as long as 6 to 9 m. However, this notch length is determined based on the length (l' in the figure) between the welded parts 4, 4 of the corresponding existing annular plate 1' (see Figure 3). For example, for section a, the length is (l' + 2l'' = l), which is a certain length l'' (300 mm) outward on both sides of l', and from the second section b...
In section n, a notch is made to length l' to facilitate cutting and replacement of the corresponding existing annular plate 1'.

That is, in section a, the corresponding existing annular plates 1' are cut 4', 4' outward from the weld lines 4, 4 at positions that take l'' into account, and after being removed, the 4, All you need to do is lay a new annular plate 1 with a length (l') corresponding to the position in position 4 (see Fig. 4), and for the second section b and subsequent sections...n, install the corresponding existing annular plate 1'. What is necessary is to sequentially cut the weld line 4 at positions taking the circumferential direction l'' into account, and each time, install a corresponding new annular plate 1 in the same manner as described above.

In this way, the existing annular plates 1' are successively replaced with new plates 1, but this method is not particularly different from the means conventionally employed in this type of construction method. Reference numeral 5 denotes a guide plate made of a thick steel plate with a rectangular side surface, which is placed along the circumferential wall (inner circumferential wall in this figure) of the notched end of the side plate notch 3 (hereinafter referred to as the notched end of the side plate) 2'. As shown in the figure, a plurality of them are erected on the new annual plate (bottom welded) to minimize lateral shaking caused by wind force, earthquakes, etc. that the tank side plate 2 receives during the construction period, and after the preliminary construction (described later) is completed, the tank body It functions as a good guide board when descending. However, it goes without saying that the installation position of the lever guide plate 5 is not limited to the inner circumferential wall of the notch end 2' of the side plate, but may be installed on the outer circumferential wall or on both the inner and outer circumferential walls (however, it may be provided on both the inner and outer circumferential walls). They are non-opposed (inconsistent).

6 indicates a taper down device, and this device 6 is the fourth
~6 As shown in the figure, there is a base 7 with an L-shaped cross section, and a shaft (hereinafter referred to as shaft) with a screw 8' that is screwed into the screw hole that passes through the center of the rising part 7'. ) 8 and a tapered metal fitting (hereinafter referred to as taper metal fitting) 9 having a knife-like cross section and fixed by welding to the shaft end. Thumb screws 10 and 11 are screwed into the shaft 8 so that the shaft 8 itself can be moved forward and backward, or restricted or fixed, and both of these screws are attached to the base 7. They are located on both sides of the rising portion 7'. Further, the tapered metal fitting 9 has a necessary inclination angle α (toward the bottom surface) to catch the notch end on its back slope when the metal fitting 9 is pushed into the notch 3 (see Fig. 5). Has a slope.

Therefore, the taper down device 6 is now arranged perpendicular to the notch 3 of the side plate 2 as shown in Figures 5 and 6, and the bottom of the base 7 is welded onto the bottom plate 12 (however, if the installed annular plate is wide When the thumbscrew 10 is rotated counterclockwise, the tapered metal fitting 9 moves forward as the shaft 8 moves forward, so the tapered metal fitting 9 can be moved to the desired position. If you want to fix it, move the metal fitting 9 forward to the desired position as described above, move the thumbscrew 11 (backwards) to the position of the rising part 7' of the base 7, and fix the rising part 7' on both sides. It is only necessary to firmly clamp it together with the wing screw 10 (see Fig. 5). In this way, the tapered metal fitting 9 is fixed at a desired position.

Conversely, in order to move the tapered metal fitting 9 backward from the fixed position to a desired position and fix it at that position, rotate the thumbscrew 10 clockwise as shown in Figure 6 to move the shaft 8 backward ( If the tapered metal fitting 9 is moved backward, the thumbscrew 11 is moved back at the desired position.
This is achieved by firmly holding the rising portion 7' of the base 7 from both sides as described above.

In this way, the tapered metal fitting 9 always moves back and forth along with the shaft 8, which moves back and forth as the thumbscrew 10 rotates, so this movement is performed in stages, and the thumbscrew 11 is adjusted each time as described above. By operating the tapered metal fitting 9, the tapered metal fitting 9 can be fixed stepwise and easily at any desired position.

Therefore, the taper down device 6 equipped with the tapered metal fittings 9 is arranged perpendicularly to the notch 3 of the side plate as described above, and the bottom of the base 7 is laid down to form a bottom plate that forms the same horizontal plane as the annular plate 1. 12 as shown in the fourth figure, and operate the thumbscrews 10 and 11 to positively push the tapered metal fitting 9 between the notch 3 and the laying annular plate 1 (see Figure 5).
By making tight contact with the notch end, the side plate load applied to the notch 3 of the side plate can be supported by the tapered metal fitting. In this case, it goes without saying that by applying a plurality of taper down devices 6 per section, the side plate load can be evenly supported.

Next, the construction order of this invention will be explained.

(1) First, in the sections a, b, c, ... n (see Figure 1) set in the circumferential direction by conventional means, for example, if a and the opposite g are decided to be the sections where construction starts simultaneously, then Perform the following construction work for each section (however, the work is the same for both sections, section a will be described below).In other words, cut out the lower part of the side plate 2 to a width of 30 mm (based on the bottom plate) and a certain length, and fit through the cutout part 3. The existing annual plate 1' is cut 4', 4' at the same location as the notch 3 (see Figure 3) as described above, and after being carried out, the ground is corrected and the corrected surface is cut 4', 4'. A new annular plate having a length l' corresponding to the length between the two is laid adjacent to the bottom plate 12 at the position of the old ones 4, 4 so as to form the same horizontal plane (see FIG. 4).

(2) On this new annual plate, a plurality of guide plates 5 are erected (bottom welded 5') along the inner peripheral wall of the notch 2' of the side plate as described above (see Figure 4). ).

(3) The taper down device 6 is disposed on the bottom plate 12 in correspondence with the side plate notch 3 as shown in the fourth figure. The installation position is perpendicular to the notch in the opposite side plate, and the position is such that the back slope of the tapered metal fitting 9 provided at the end of the shaft 8 can move (advance) into the notch by operating the thumbscrews 10 and 11. The lower bottom portion of the table 7 is welded and fixed 13 to the bottom plate 12 as shown in the figure (see FIGS. 5 and 6). However, if the new annular plate 1 is wide, it will be on the annular plate 1.

(4) Operate the thumbscrews 10 and 11 to actively push the tapered metal fitting 9 into the side plate notch (between the notch end and the laying annular plate) and firmly contact the notch end to close the notch. The side plate load applied to the notch is supported. In this case, if necessary, a plurality of the devices 6 may be used per compartment to evenly share the side plate load.

In this way, while completing the necessary construction work in (1) to (4) above for sections b, c, ...f starting from section a,
In order to complete the same necessary construction for sections h, i,...n starting from section g, the total vertical load of the tank is distributed equally to each of the multiple tapered metal fittings installed in sections a, b,...n. It will be supported.

However, in the above, the construction work may be carried out in a circumferential direction starting only from section a, for example, without starting construction in two sections (a, g), but this is inferior to the former in terms of construction period. It is also possible to proceed with construction work in different directions simultaneously from one section as a starting point, but this is not preferable due to the balance between the notch and the vertical load on the tank.

(5) Next, when the above-mentioned works are completed, the adjacent annular plates are welded 14,
14... (See Figure 8) After completing the laying of the desired series of new annular plates, the annular plates 1 and the bottom plate 12 are welded together in the same manner as described above to complete the first step of the construction method. .

(6) Next, the tank body is lowered onto a series of welded annular plates, which is done as follows.

That is, a large number of taper down devices 6, 6, ... are inserted in the notch portions extending all around the lower part of the side plate.
Select a group of devices located at equal intervals, such as every other or second device, depending on the base number, and turn the thumbscrews 10 and 11 of the devices simultaneously and the same number of times as described above to attach the taper metal fittings. When the side plate load is supported by the non-retreating taper metal fittings group by retracting the metal fittings by a certain distance, next operate the thumbscrews 10 and 11 of the non-retreating taper metal fittings group in the same manner as described above (at the same time and the same number of times). When the tapered metal fitting is moved back a certain distance, the side plate follows the retraction of the metal fitting and smoothly lowers the opposing portions of the plurality of guide plates 5 set up along the peripheral wall of the side plate by a certain distance, completely covering the entire side plate. The load is evenly supported by the tapered metal fittings group that has been retracted before the main operation. In this case, the descending distance is exactly 1 mm, but this 1 mm can be satisfied by determining in advance the number of turns (number of screws) of the thumbscrew.

Therefore, if such an operation is performed for each group of taper metal fittings alternately and stepwise (in 1mm increments), the side plate will be lowered step by step and accurately in 1mm increments while supporting the taper metal fittings group, and the lower part of the side plate will be lowered. Since it will come in close contact with a predetermined position on the new annular plate installed on the new annular plate, after confirming its quality, (a) Cut from the base (welded part) and repair the cut part. Next, (b) after welding the abutting part of the lower end of the side plate and the new annular plate together by a conventional method over the entire circumference, the base of the taper down device is separated from the welded part; The entire construction process using this method is completed by welding the remaining parts and other unwelded parts.

The above is an example of replacing the annual plate around the entire circumference of the tank, but even when replacing it partially, repeat the same operation as above after relining only the required part based on the above method. This allows construction work to be carried out smoothly without buckling or distorting the side panels.

In addition, when re-covering all or part of the bottom plate, carry out the same procedure as in the previous example by removing the bottom plate that needs to be replaced by cutting it from the notch at the bottom of the side plate using the usual method, correcting the foundation of the ground after carrying it out, and then placing a new By laying the bottom plate and welding its periphery together with the adjacent bottom plate, the desired replacement of the bottom plate is completed. Next, the tank side plate may be lowered in accordance with Example 6.

As explained in detail above, the present invention involves cutting out the lower part of a tank side plate evenly in a band shape in a certain section in the circumferential direction, and cutting an existing annular plate corresponding to the cutout portions into the cutout portions. In the tank annual plate relining method, in which a new annual plate corresponding to the position after being carried out is sequentially laid through a tank, (a) a corresponding new annual plate is sectioned at the corresponding position after the existing annual plate is carried out. A plurality of guide plates are installed on the annular plate adjacent to the bottom plate, and a plurality of guide plates are erected on the annular plate along the circumferential wall of the notched end of the tank side plate, and between the notched end of the side plate and the new annular plate. (b) It consists of a movable shaft connected to a tapered metal fitting and having a screw carved therein, a thumbscrew that is screwed into the shaft so as to be able to move forward and backward, and a side L-shaped base that has a rising portion into which the shaft is screwed. Place the taper down device orthogonally to each notch in the side plate, and after welding the bottom of the L-shaped base to the bottom plate or the new annual plate adjacent to the bottom plate, rotate the thumbscrew to the forward direction. , the tapered metal fitting at the end of the shaft was pushed between the lower end of the notch in the side plate and the new annual plate, and the entire vertical load of the side plate was evenly distributed to the back slopes of multiple taper metal fittings, and then the adjacent new annular plate was installed. After finishing the preliminary work by welding the annular plates together and between the annular plates and the adjacent bottom plate, (c) we installed multiple taper down devices interposed in the notches extending all around the lower part of the side plates. Alternatively, select a group of such devices located at equal intervals, such as every two, and simultaneously rotate their thumbscrews in the backward direction a certain number of times to simultaneously move the tapered metal fittings back a certain distance, and reduce the side plate load to the non-backward taper. After being supported by the metal fittings group, (d) the thumbscrews of the non-retreating taper metal fittings group are simultaneously rotated to the backward movement side in the same way as described above to simultaneously retract the taper metal fittings by a certain distance, and the side plate load is transferred to the second non-retreating taper metal fittings. By supporting the side plate in groups, when the side plate is lowered, the facing portions of a plurality of guide plates erected along the lower peripheral wall of the side plate are lowered by a certain distance in a sliding manner.The above operation is repeated alternately. (a) ~ (d) Since it is an inseparable construction method,
The practical effects are remarkable, such as fully demonstrating the following effects, greatly shortening the construction period of this type of work (especially for large tanks) known in the past, and enabling safe and economically advantageous construction.

Since the guide plates were erected on the new annual plate in each section along the peripheral wall of the notched end of the side plate as described above, it was possible to effectively prevent abnormal lateral vibration of the side plate due to wind force or earthquakes during the construction period. Furthermore, when the tank body is lowered, it contributes to vertically guiding the side plate, thereby eliminating misalignment of the contact position with the new annular plate.
Another side effect is that the pieces cut up after construction is completed can be reused as guide boards.

Operate the thumb screw of the taper down device installed on the bottom plate or the new annual plate adjacent to the bottom plate perpendicularly to the notch in the side plate (as described above).
After pressing the taper metal fittings tightly between the notch end and the annular plate, select a group of taper metal fittings located at equal intervals, such as every other one, and operate their thumbscrews simultaneously as described above. and simultaneously retract by a certain distance (1 mm: the same applies hereinafter), the side plate load is supported by the non-retracting taper metal fitting group, and then the thumbscrews of the non-retracting taper metal fitting group are simultaneously operated in the same manner as above to retract by a certain distance, Because the construction method uses a construction method that alternately repeats the above operation of supporting the side plate load on the secondary receding tapered metal fittings and simultaneously lowering the side plate a certain distance, this combined with the above effects effectively prevents uneven loads on the tank side plate. This can prevent buckling and distortion. Therefore, unlike the conventional method, a support member is not fixed between the notch and the annular plate.
Not only can the fixing process etc. be omitted, but there is no need to cut the support member to the same size each time the tank body is lowered, and construction can be carried out safely and economically.

It goes without saying that the method of the present invention is not limited to the above-mentioned storage tanks for petroleum, but can also be applied to general chemical storage tanks to obtain good effects.

[Brief explanation of the drawing]

The drawings show one embodiment of the invention.
The figure is a schematic plan view showing the state of the divisions equally distributed along the circumferential direction during construction of this construction method, Figure 2 is a partial side view of the tank side plate, and Figure 3 is the lower part of the tank side plate divided into divisions. An explanatory diagram showing cut points in a belt-like notch of equal width and a corresponding annual plate that requires replacement. Figure 4 shows a guide plate being erected on the newly installed annual plate along the peripheral wall of the corresponding notch, A schematic perspective view showing the arrangement state of the taper down device with a part of the side plate cut away; FIGS. 5 and 6 are explanatory views partially showing the forward and backward moving state of the taper metal fitting in the taper down device; FIG. 7 and FIG. 8 are schematic explanatory diagrams showing the construction order of the present invention. 1... New annular plate, 2... Tank side plate, 3... Notch, 4... Welded part of existing annular plate, 5... Guide plate, 6... Taper down device, 7... L type Base, 8...Shaft, 9...Tapered metal fittings, 10, 11...Thumb screws, 12...Bottom plate, 1
3... L-shaped base welding part, 14... Welding part between new annular plates.

Claims (1)

[Claims] 1 Cut out the lower part of the tank side plate in the circumferential direction, evenly and in a band shape in each certain section, cut the existing annular plate corresponding to the notched part, and create a new annular plate corresponding to the position after being carried out. In the method of relining the tank's annular plate, in which the cut-off existing annular plate is carried out, a new annular plate corresponding to the position is laid adjacent to the bottom plate in each section, and the annular plate is A plurality of guide plates are erected along the circumferential wall of the notched end of the tank side plate, and then between the notched end of the side plate and the new annual plate, a movable shaft is connected to a tapered metal fitting and has a screw carved therein. A taper down device is arranged perpendicularly to each notch in the side plate, and includes a thumbscrew that is screwed into the shaft so as to be able to move forward and backward, and a side L-shaped base that has a rising portion into which the shaft is screwed. Then, after welding the bottom of the L-shaped base to the bottom plate or the new annular plate adjacent to the bottom plate, rotate the thumb screw in the forward direction to connect the tapered metal fitting at the shaft end to the lower end of the notch in the side plate and the new annular plate. After pushing between the plates and distributing the entire vertical load of the side plates evenly to the back slopes of the multiple tapered metal fittings, the new annual plates were installed between each other, and between the new annual plates and the adjacent bottom plate, respectively. After welding and completing the preliminary work, select a group of taper down devices located at equal intervals, such as every one or two, with multiple taper down devices installed in the notch extending all around the lower part of the side plate. After simultaneously rotating the thumbscrews in the backward direction a certain number of times to simultaneously retract the taper metal fittings by a certain distance and allowing the side plate load to be supported by the non-retreating taper metal fitting group, the thumbscrews of the non-retreating taper metal fitting group are moved backward in the same manner as above. By simultaneously rotating to the side and retracting the taper metal fittings by a certain distance at the same time, the load of the side plate is supported by the secondary non-retracting taper metal fitting group, so that when the side plate is lowered, multiple guides erected along the lower circumferential wall of the side plate are supported. A method for relining annular plate or bottom plate of a tank, characterized by repeating alternately the above-mentioned operation of lowering the side plate by a certain distance so that the opposing parts of the plate are in sliding contact.