JPS6213468B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for assembling a floating roof in a floating roof tank for storing heavy oil or other volatile liquids.

As is well known, floating roof tanks have a so-called floating roof floating above the liquid level stored in the tank body to seal the liquid level and prevent vaporization of the stored liquid. It is valued as an extremely useful tank due to its low losses.

Therefore, recently it has been proposed that this floating roof tank be used not only for above-ground tanks but also for underground tanks and other large tanks of 100,000 Kl class for oil storage purposes.

By the way, when assembling a floating roof, generally,
When assembling the tank body, first a pedestal is provided on the bottom plate of the tank body, and then the components of the floating roof are carried into the tank body. It is normal to then assemble the components by sequentially joining them on a pedestal.

However, such an assembly method is difficult to use when the tank is not very large, for example when the diameter of the floating roof is 30
~40m apart, the diameter is 70~80m.
In the case of a floating roof larger than 1.5 m, a considerable amount of work is required just to transport the floating roof components into the tank, which is a big problem from the standpoint of work efficiency and cost.

In particular, if this conventional method were to be applied to the floating roof of an underground tank, it would be necessary to bring the components into the tank from a fairly high position, which would have a significant impact on assembly work efficiency and work safety. There is a problem.

Therefore, instead of assembling it on the tank bottom plate,
As illustrated in the figure, a special yard 2 for assembling the floating roof is temporarily constructed next to the tank body 1 to be constructed, and after the assembly is carried out in this yard 2, the floating roof is filled with water and floated. A method has been proposed in which the material is brought into the tank in a state in which it is removed.

However, both the method of assembling on the tank bottom plate and the method of assembling by setting up a special assembly yard have drawbacks in assembling large floating roofs, and there is a need to develop safer and more rational assembly methods. This is where I am.

Against this background, the present invention has developed a method for assembling a large floating roof using the block construction method, which is more rational, safer, and can shorten the construction period.

The unique feature of the assembly method is that water is filled in the tank body, a center floating block corresponding to the center of the floating roof made in advance at the factory is floated on the water surface, and center floating blocks are placed around the floating block. Similar to the block, a segment-shaped unit floating block manufactured in advance at a factory is connected to a concentric ring body centered on the center floating block on the liquid surface, and the center floating block and the ring body are connected to each other, and the required diameter is It is characterized by being assembled into a floating roof with a circular shape.

That is, a center floating block is floated on the liquid surface, and unit floating blocks surrounding it are connected to a concentric ring body on the liquid surface to form a floating roof using the so-called block construction method.

Furthermore, the second feature is that when connecting segment-shaped unit floating blocks around the center floating block, first pull the center floating block as close to the tank peripheral wall as possible, and then connect the segment-shaped units at that position. The first unit floating block is connected, and when the connection is completed, the whole unit is pivoted in a certain direction around the center floating block, and in the moved state, the next unit floating block is connected.

In other words, so that the unit floating blocks can be connected at the position where the first unit floating block was connected, the units are rotated in a fixed direction around the center floating block, and the whole unit is sequentially moved to the center of the tank, while the unit floating blocks are connected at all times. This is done at a fixed location near the surrounding wall.

Next, this assembly method will be specifically explained based on an example. The floating roof tank to which this assembly method was applied in the examples is a large underground tank intended for crude oil storage, as shown in Figure 2, where R is the floating roof and T is the tank body. It is the surrounding wall of Floating roof R, as shown in Figure 2, is similar to the so-called double deck type structure, with upper and lower deck plates made of flat plates arranged, and the upper and lower deck plates separated by a partition plate to create a floating room. However, the whole is divided into blocks as shown in FIG.

That is, an appropriate number of unit floating blocks 12 divided into segments around a circular center floating block 11 are connected to a concentric ring body, and an appropriate number of unit floating blocks 12 are wound concentrically (in the embodiment). It is wrapped in 5 layers.

Of course, both the center floating block 11 and the segment-shaped unit floating blocks 12 are manufactured at the factory, and each has completed an airtight test and has undergone temporary assembly tests at the factory, and can be assembled on-site. A pre-check has been carried out to ensure that there are no problems.

Below, the assembly procedure of the floating roof R will be explained. First, as shown in FIG. Leave it in place.

Then, using this crane C, first, the center floating block 11 is carried onto the liquid level in the tank.

At this time, the center floating block 11 is placed as close to the tank peripheral wall T as possible, as shown in FIG. Next, as shown in FIG. 6, using the crane C, a segment-shaped unit floating block 12 is
is carried in and connected to the outer periphery of the center floating block 11.

When the connection work is completed, the whole is rotated around the center floating block 11. In the illustration, it is rotated clockwise to connect the next unit floating block 12 to the first unit floating block 1.
Rotate the center floating block 11 so that it can be placed at the same place where the two are connected.

FIG. 7 shows the point in time when the above operations are repeated and the connection of the unit floating blocks 12 has been completed to approximately the middle of the whole. Reference numeral 13 shown in FIGS. 6 and 7 is a winch for turning the center floating block 11 after the connection work has been completed, and it is placed at a fixed location along the tank peripheral wall T, and the tip of the wire 14 of this winch 13 is connected to the center floating block 11 side, and the entire body is rotated by being wound up.

FIG. 8 is a side view of FIG. 7, and shows an intermediate process of connecting the unit floating blocks 12.

The unit floating blocks 12 are successively connected by repeating the above operations, and finally the whole is assembled into a disk shape.

FIG. 9 shows an example of the connecting portion of each unit floating block 12. A flange 15 is provided on the periphery of each unit floating block 12, and the flanges 15 are overlapped and connected through an airtight packing. They are connected using a bolt fastening method. Reference numeral 16 denotes a cover plate provided on the upper surface, which seals the upper surface of the joint of each unit floating block.

In this embodiment, as described above, the individual unit floating blocks 12 are connected by bolt fastening, but the connection method is not limited to this method. It is also possible to use a welding method or the like.

The assembly method of the present invention has the following advantages since the floating roof is assembled by the procedure described above.

First, because the floating roof is divided into several parts using the block construction method, assembly work can be done rationally and efficiently.

Second, since each divided block is connected and assembled on the liquid surface, the work is easy, unlike a simple block construction method.

That is, in the case of an underground tank like the embodiment, according to the conventional construction method, the floating roof member must be suspended up to the top of the tank bottom plate. Normal capacity is 100,000Kl
In the case of a large tank such as this one, the depth of the tank is more than 20 meters, so the work of hoisting the parts is a huge undertaking.

In this respect, in the method of the present invention, since the work is performed on the surface of the liquid in the tank, it is much easier to assemble the entire tank as well as to suspend it.

Thirdly, in the process of bringing in and connecting each unit floating block, the parts that have already been connected are rotated on the liquid surface, so the loading position of the next block is fixed, that is, the working position is limited. The overall work is efficient.

In particular, since the turning movement is performed above the liquid surface, it can be easily performed without requiring excessive effort.

Fourthly, at the same time that the work place is limited to a certain level,
Since the assembled part is rotated and moved toward the center of the tank, the floating roof itself is automatically set at the center of the tank body at the time of final work.

Therefore, as explained at the beginning, compared to the method of setting up a special assembly yard and moving the assembled floating roof from there into the tank, the entire assembly work can be carried out more rationally. This will also greatly contribute to reducing construction costs.

As described above, this assembly method is superior to conventional assembly methods in terms of work efficiency, safety, and economy, and is extremely suitable as a floating roof assembly method for large tanks.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an example of a conventional assembly method;
Figure 2 is a longitudinal cross-sectional view of an underground tank with a floating roof to which this assembly method is applied, Figure 3 is a plan view of the floating roof, and Figure 4 is a crane for transporting each floating block in this assembly method. 5th side view showing the arrangement of
The figure is a plan view, FIGS. 6 and 7 are plan views showing the assembly process of each floating block, FIG. 8 is a side view of FIG. 7, and FIG. 9 is an example of the connection structure of each floating block. FIG. 1...Tank body, 2...Yard, 11...Center floating block, 12...Unit floating block, 13...Winch, 14...Wire, 15
...Flange, R...Floating roof, T...Tank peripheral wall, S...Floating roof sealing device, C...Crane.

Claims (1)

[Claims] 1 Fill the tank body with water, float a circular center floating block corresponding to the center of the floating roof on the liquid level, and place an appropriate number of segment-shaped unit floating blocks around the center floating block. The center floating block is connected to a concentric ring body, and the center floating block and an appropriate number of concentric unit floating blocks connected to the ring body are connected to each other to form a floating roof of the required diameter on the liquid level in the tank. A method for assembling a floating roof in a large floating roof tank, characterized in that the floating roof is assembled at the top of the tank.