JPS5846992B2 - Welding assembly method of bottom plate in tank construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention primarily relates to a method for assembling the bottom plate of a large double-shell cryogenic tank by welding it from both sides.

Conventionally, in tank construction using the jack-up method, there are the following methods for assembling the bottom plate by butt welding.

B. In Fig. 1, an annular pearlite concrete is formed on the foundation 2 and the outer tank bottom plate 3, and the array of annual plates 5, a part of the side plate 6, and the roof part 9 are assembled thereon. A special composite jack 1 was installed, the bottom cold insulation layer 7 was constructed as shown in Figure 2, and the bottom plate 8 was installed.
are arranged, and the bottom plate is welded from one side of the upper side on top of the cold insulation layer 7.
The roof part 9 and the bottom plate 8 are connected with a wire 10, and as shown in FIG.
2, jack up the entire tank via 2, install a pedestal under the bottom plate 8, and perform welding and inspection from the bottom of the bottom plate 8. 2. In Figure 4, remove the pedestal after completing the inspection of the bottom plate 8. , E. In FIG. 5, the tank is jacked down and the bottom plate 8 is lowered onto the cold insulation layer, and the wire 10 is removed. From then on, tank construction is proceeded by the well-known jacking up method.

This conventional construction method has the following drawbacks.

B. In Fig. 1, jack 1 is connected to annual plate 5.
Although it is installed on top of the jack 1, since the prop of the jack 1 is long, the diagonal member 15 that supports the prop protrudes from a normal annular plate, so some kind of countermeasure is required.

As shown in Figure 2, the construction of the bottom cold insulation layer 7 will be carried out, but since the jacks 1 are large and a considerable number of jacks need to be lined up, measures to prevent rainwater from entering during the cold insulation work are uncertain, and the cold insulation work is not completed. Rainwater infiltration becomes a problem.

C. The bottom plate 8 is arranged on the cold insulation layer 7 and welded from one side on the upper side. However, if the bottom plate is in contact with the cold insulation layer 7, complete butt welding is not possible even if welding is also performed from the bottom side on the stand later. It is difficult to do so.

2. In Fig. 2, if the diagonal member 15 of the jack 1 is large and located at the end of the annular plate 5, the bottom plate 8 is usually made larger than the inner diameter of the annular plate 5, and the annular plate is attached after welding and assembly is completed. It is difficult to install the bottom plate because it is cut to match the inner diameter of the bottom plate.

E. In FIG. 3, when a frame is installed on the cold insulation layer 7, a special design is required to increase the compressive strength of the cold insulation layer 7, which is uneconomical.

In Figures 2 and 3, the bottom plate 8 can only be installed after the assembly of part of the side plate and the roof is completed.
While the bottom plate 8 is being constructed, the tank body cannot be constructed, resulting in a long construction period.

The present invention eliminates all the drawbacks of the conventional case described above, and in tank construction using the jack-up method, a special wide annular plate is arranged on the annular pearlite concrete on the bottom plate of the outer tank. After assembly, a side plate feed roller device for jacking up is arranged to match the circumference of the side plate, a special composite jack is installed inside the roller device, and a part of the inner tank side plate is assembled into an annular shape at the upper end of the side plate. Connect, assemble and install the roof,
In parallel with the work of assembling, welding and various inspections of these side plates and roof parts, supports for arranging bottom plates are arranged inside the tank, inner tank bottom plate base materials are arranged on these supports, welding of the bottom plates and various inspections are carried out, The inner tank side plates and roof are jacked up by the special composite jack at least by the amount necessary to jack down the bottom plate onto the cold insulation layer later, the inner tank is supported by a pedestal, and the roof and bottom plate are connected with wire. After joining and removing the support, a ring-shaped partition plate was fixed all around the upper surface of the annual plate as a measure to prevent the intrusion of rainwater, construction of the bottom cold insulation layer was carried out, and the entire inner tank was jacked down to keep the bottom plate cold. This is a method of welding and assembling a bottom plate in tank construction, which is characterized by lowering it onto a layer.

The configuration of the present invention will be explained using examples and drawings.
In FIG. 8 and FIG. 9, an additional annular plate 5a is added to the straight side of the annular plate 5 toward the inside of the tank.
Butt welding is performed at the factory to produce and use a wide annular plate with special dimensions.

As shown in FIG. 6, the width of the conventional annular plate 5 is limited due to economic efficiency and the steel plate manufacturing capacity of the steel manufacturer, and the width of the conventional annular plate 5 is insufficient for the present invention.

The pentagonal additional annular plate 5b is welded during on-site assembly.

Now, after arranging and assembling this wide annular plate 5 on the annular pearlite concrete 4 on the outer tank bottom 3 laid on the tank foundation 2 as shown in FIG. A known special composite jack 1 is installed inside the roller device 11 along with its circumference.

In FIG. 13, the roller device 11 consists of a roller support portion 11a and a roller 11b pivotally supported by the roller support portion 11a, and receives the lower edge of the side plate 6 at the groove bottom of a channel 11C placed on the roller itb.

The side plate 6 can ride on the channel 11c and move smoothly on the roller 11b.

A part of the inner tank side plate 6 is assembled in an annular shape on this roller device 11, connected to the upper end of the side plate 6, and the roof portion 9 is assembled and attached.

In parallel with the work of assembling, welding, and various inspections of the side plates 6 and roof portion 9, supports 13 for arranging the bottom plates are arranged and erected on the outer tank bottom 3 inside the tank.

The upper ends of the supports 13 are connected by a reinforcing member 16, and the inner tank bottom plate base material is arranged on the reinforcing member 16, and the bottom plate 8 is welded and various inspections are performed.

Next, in FIG. 11, by the special composite jack 1,
The inner tank side plates 6 and the roof part 9 are jacked up at least as much as necessary to jack down the bottom plate 8 onto the cold insulation layer 7 later, and the inner tank is supported by the frame 17, and the roof part 9 and the bottom plate 8 are jacked up. are connected by wire 10, and wire 10
The bottom plate 8 is slightly floated horizontally by operating the turnbuckle 18 interposed in the middle of the reinforcing material 16.
After confirming that it has moved away from support 13 in Figure 12
Then, the construction of the bottom cold insulation layer 7 is carried out with the reinforcing material 16 removed and the bottom plate 8 suspended from the roof part 9.

In order to prevent rainwater from entering during this cold insulation layer construction, a partition plate 19 is fixed in an annular shape on the annular plate 5 as shown in FIG. Install it.

After the construction of the bottom cold insulating layer 7 is completed, the side plates 6, the roof part 9, and the entire bottom plate 8 are jacked down with the jack 1, so that the bottom plate 8 is lowered onto the cold insulating layer 7, and the wire 1
Remove 0.

Thereafter, all of the side plates 6 are assembled using the well-known jack-up method to construct the entire tank.

The outer tank side plates 16 and the roof may be assembled at appropriate times.

Note that the construction of the cold insulation layer 7 can also be carried out without removing the supports 13 for safety.

In FIG. 15, a short tube 13c is fixed on the outer tank bottom plate 3, and the short tube 13c is fitted into the outer tube 13a.
3a up and down so that it can be pulled out and inserted freely, and the outer tube 13
A thin film, such as a vinyl chloride film 13e, is placed on the outside of the tube 13a to an appropriate height, and a pin hole 13b is formed in the upper part of the outer tube 13a, so that the inner tube 13d is inserted into the outer tube 13a from above.
is inserted into the pin hole provided in the inner tube 13d and the outer tube 13.
The support 13 is constructed by inserting a pin in accordance with the position of the pin hole 13b of a.

After constructing the cold insulation layer 7 as shown in FIG. 12 with this support 13 upright, in FIG. 13d upward.

At this time, since the outer tube 13a is covered with the thin film 13e, the cold insulation layer 7 does not adhere to the outer tube 13a and can be easily pulled out.

The hole left after pulling out the outer tube 13a is filled with pearlite concrete, and the short tube 13c is embedded in the cold insulation layer 7.

According to the present invention, firstly, since a wide annular plate is used, the diagonal member of the special composite jack can be easily installed without protruding from the annular plate, and secondly, a part of the inner tank side plate can be easily installed. are assembled in a ring shape, connected to the upper end of the side plates, and the roof section is assembled and installed.In parallel with the work on these side panels and the roof section, work such as alignment, assembly, and inspection of the bottom plate is performed inside the tank at the same time, so the construction period is significantly reduced. Thirdly, since the bottom plate arrangement is assembled on a frame consisting of supports erected on the bottom plate of the outer tank, there is no need to take special measures to increase the strength of the bottom cold insulation layer, making it economical. The construction of the bottom cold insulation layer is carried out with the side plates and roof supported by jacks and frames, and the bottom plate suspended from the roof with wires, so the work can be carried out safely.
After the bottom plate is jacked down on the cold insulation layer, the entire tank is jacked up in advance, and the roof and bottom plate are connected with wire, and the bottom plate is jacked down after the construction of the bottom cold insulation layer is completed, making the work smooth. 0. Effects such as safe performance are recognized.

[Brief explanation of the drawing]

Figures 1 to 5 are longitudinal cross-sectional views for explaining the conventional case;
Figure 6 is a plan view for explaining the conventional annular plate;
The figure is a longitudinal sectional view taken along the line A-A in FIG. 6, and FIGS. 8 to 15 are for detailed explanation of the present invention, and FIG. 8 is a plan view of the annular plate portion. , No. 9
The figure is a longitudinal sectional view taken along line B-B in Figure 8, and Figure 10.
15 to 15 are longitudinal sectional views. 1... Special composite jack, 2... Tank foundation, 3... Outer tank bottom plate, 4... Annular pearlite concrete, 5... Annular plate, 5a, 5b... Additional annular plate, 6... Inner tank side plate, 7... Cold insulation layer, 8... Inner tank bottom plate. , 9... Roof section, 1
0...Wire, 11...Roller device, 11a...Roller support part, 11b...
...roller', 11c...channel, 1
2...Consignment receiving section, 13...Support, 1
3a...Outer tube, 13b...Pin hole, 1
3c...Short pipe, 13d...Inner pipe, 13
e... Thin film, 14... Outer tank side plate, 15
...Diagonal material, 16...Reinforcement material, 17.
・・・・・・Frame, 18・・・Turnbuckle, 1
9...Partition plate, 20...Cover, 21
...Bottom plate stiffener-0

Claims (1)

[Claims] 1 In tank construction using the jack-up method, after arranging and assembling special wide annular plates on the annular pearlite concrete on the outer tank bottom plate, a side plate feed roller device for jack-up is arranged to match the circumference of the side plate. At the same time, a special composite jack is installed inside the roller device, and a part of the inner tank side plate is assembled in a ring shape, connected to the upper end of the side plate, and the roof section is assembled and attached.Assembling, welding, and various inspections of these side plates and the roof section. In parallel with this work, supports for bottom plate arrangement are arranged on the outer tank bottom plate inside the tank, the inner tank bottom plate base material is arranged on the supports, welding and various inspections of the bottom plate are carried out, and the special composite jack is used to reduce the Later, the inner tank side plates and roof are jacked up as much as necessary to jack down the bottom plate onto the cold insulation layer, the inner tank is supported by a frame, the roof and bottom plate are connected with wire, and the supports are removed. At the same time, tank construction is characterized by fixing a ring-shaped partition plate around the entire upper surface of the annual plate, then constructing the bottom cold insulation layer, and then jacking down the entire inner tank to lower the bottom plate onto the cold insulation layer. Method of welding and assembling the bottom plate.