JPH10316193A - Floating roof storage tank deck repair method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Even if a relatively large penetration occurs, it is possible to prevent the outflow of the floating roof storage tank without stopping use of the storage tank and safely repair the penetration of the deck. A method of repairing a deck of a floating roof storage tank is provided. SOLUTION: A plurality of hollow tubes 10 extending vertically through a deck 3 and having an upper end located above a draft 8a are dispersed on a deck surface and attached in advance in a watertight manner. At the time of repair, insert the hollow elastic bag 12 into the lower surface of the deck through the hollow tube,
Next, a compressed gas is supplied into the hollow elastic bag through the tube 12a to expand the bag. By inserting a plurality of hollow elastic bags from a plurality of hollow tubes and inflating them, the buoyancy of the floating roof is increased, and the draft 8a can be lowered to the lower surface of the deck for repair. In addition, the hollow elastic bag is inserted into the lower surface of the deck having the through portion through the hollow tube adjacent to the deck through portion 9 and inflated, and is closely attached to the lower surface of the deck surrounding the through portion to seal the through portion from the lower surface of the deck. Can be repaired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for repairing a deck of a floating roof type storage tank.

[0002]

2. Description of the Related Art FIG. 4A is a schematic view of a floating roof type storage tank used as an oil tank for petroleum or the like. In this figure, 1 is a foundation, 2 is a side plate, 3 is a deck, 4 is a pontoon, 5 is a sealing device, 6 is a weather shield, and a floating roof 7 is composed of a deck 3, a pontoon 4, a sealing device 5 and a weather shield 6. Be composed.

FIG. 4B is an enlarged view of a portion A in FIG.
In the floating roof type storage tank, the contents 8 such as petroleum are usually flammable, so that the draft 8a of the contents 8 is set higher than the deck 3. Therefore, the pontoon 4 that generates buoyancy is usually provided above the periphery of the deck 3. The sealing device 5 is a ring-shaped elastic member, and seals between the outer peripheral surface of the pontoon 4 and the inner surface of the side plate 2. The weather shield 6 is a thin plate whose lower end is attached to the upper surface of the pontoon 4 and whose upper end slides on the inner surface of the side plate 2, so that rainwater or the like does not enter the sealing device 5.

Although the deck 3 shown in FIG. 4 is of a single deck type composed of one metal plate, there is also a case of a double deck type wherein the deck 3 is composed of two metal plates. .

[0005]

The above-mentioned floating roof type storage tank is a large oil tank having a diameter of, for example, about 50 m. The contents are regularly emptied at intervals of about 5 years, and inspection and repair are carried out. Is carried out. However, the deck 3 is exposed to the wind and rain, and is highly corroded. A through hole is opened during use, the liquid level fluctuates due to sloshing during an earthquake, or a wave phenomenon in a strong wind such as a typhoon. The weakest point, such as the joint, may be cracked or damaged.

[0006] Once the through-holes 9 such as through holes, cracks, breakage and the like are formed in the deck 3, the draft 8 is higher than the deck 3 as described above. (200-300 mm). Since the contents 8 are combustible materials and the deck area is very large, there is a possibility of fire or explosion, and it is difficult to remove the effluent. Therefore, when the damaged portion is large as described above, the operation schedule of the tank is changed, the contents are emptied, and the tank is repaired. However, this inspection and repair work not only costs tens of millions to hundreds of millions of yen, but also, especially when there is no spare or extra space for a large oil tank, or when there is only one tank, There was a problem that the contents could not be supplied and the operation of the entire facility had to be stopped.

In order to solve such a problem, conventionally, the upper surface of the deck is frequently inspected to repair damage due to corrosion or the like at an early stage, or the through portion is closed with a putty or the like at a slight stage.
However, there is a problem that early detection is indispensable and maintenance management is troublesome. Also, finding a small penetration part requires skill due to the effects of dirt on the deck upper surface, etc.
Missing its early detection may make it impossible to stop the outflow with putty or the like.

The present invention has been made to solve such a problem. In other words, the purpose of the present invention is to prevent the use of the floating roof type storage tank even if a penetration portion having a size that cannot be stopped by putty or the like occurs,
It is an object of the present invention to provide a method for repairing a deck of a floating roof type storage tank which can prevent the outflow and safely repair a penetration portion of the deck.

[0009]

According to the present invention, a plurality of hollow tubes extending vertically through a deck and having an upper end located above a draft are dispersed on the deck surface and are mounted in advance in a watertight manner. And inserting a hollow elastic bag into the lower surface of the deck through the hollow tube, and then supplying compressed gas into the hollow elastic bag to expand the hollow elastic bag. .

According to this method, since the upper end of the hollow tube is located above the draft, the content does not flow out through the hollow tube. This hollow tube may use an existing roof support or may be separately provided. In addition, it is preferable to cover at normal times to prevent outflow of volatile components and the like. The hollow elastic bag is a bag made of oil-resistant rubber (for example, NBR). The hollow elastic bag is inserted into the lower surface of the deck through a hollow tube, and nitrogen gas or the like is supplied to the inside to expand. With this method, the penetration portion can be sealed from the inside, and the buoyancy of the entire floating roof can be adjusted by using a large number of hollow elastic bags, so that draft can be adjusted.

According to a preferred embodiment of the present invention, a plurality of hollow elastic bags are inserted into the lower surface of the deck from a plurality of hollow tubes, respectively, and then compressed gas is supplied into each hollow elastic bag to expand the bag. Raise the buoyancy of the floating roof and lower the draft to the bottom of the deck. According to this method, a plurality of hollow elastic bags (balloons) are inserted into the lower surface of the deck using the existing roof support or a separately provided hollow tube, and compressed gas is supplied into each hollow elastic bag to expand the hollow elastic bags. By doing so, it is possible to increase the buoyancy on the lower surface side of the floating roof and reduce draft, and repair can be performed in a state where outflow of contents onto the deck is completely stopped.

Further, a hollow elastic bag is inserted into the lower surface of the deck having a through portion through a hollow tube adjacent to the deck through portion, and then the compressed gas is supplied into the hollow elastic bag to expand the deck, thereby enclosing the deck surrounding the through portion. The through portion may be sealed from the lower surface of the deck by being closely attached to the lower surface. According to this method,
One or a small number of hollow elastic bags are inserted into the lower surface of the deck from the roof support portion near the penetrating portion (damaged portion), and are inflated to closely contact the lower surface of the deck surrounding the penetrating portion to seal the penetrating portion from the lower surface of the deck. The repair can be performed in a state where the outflow of the contents is prevented.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In the drawings, common parts are denoted by the same reference numerals. FIG. 1 is a diagram schematically showing the method of the present invention, and FIG. 2 is a partially enlarged view of FIG.

In the method of the present invention, a plurality of hollow tubes 10 are dispersed over the entire deck surface and attached in advance in a watertight manner. The hollow tube 10 extends vertically through the deck 3 so that the upper end is located above the draft 8a. That is, the height of the draft 8a from the deck is 200 to 300 mm.
In this case, when the hollow tube 10 is arranged vertically, the length is set to, for example, 400 mm or more. Alternatively, the hollow pipe 10 may be arranged inclined, and in this case, the upper end is set higher than the draft 8a. With this configuration, it is possible to access the lower side of the deck through the hollow tube 10 from the upper surface of the deck without the contents 8 flowing out through the hollow tube 10.

A cover 11 having an appropriate seal is provided on the upper portion of the hollow tube 10 so that sewage does not enter the inside through the hollow tube 10 and volatile components do not flow out to the outside when not in use. The inner diameter of the hollow tube 10 is preferably set to a size that allows a hollow elastic bag described later to pass through, for example, about 80 mm or more. In addition, in the existing floating roof type storage tank,
Some roof supports have the same hollow tube as the roof support when the tank is opened, and this may be used as it is or may be provided separately.

Next, when a penetration hole 9 such as a through hole, a crack or breakage is found in the deck 3, the hollow elastic bag 12 is inserted into the lower surface of the deck through the hollow tube 10, and then the hollow elastic bag 12 is inserted.
A compressed gas is supplied to the inside to expand. The hollow elastic bag 12 is preferably a bag made of oil-resistant rubber (for example, NBR) and has a gas supply tube 12a, from which a compressed gas such as nitrogen gas is supplied to expand the inside. be able to. The hollow elastic bag 12 preferably shrinks in a rod shape so as to easily pass through the hollow tube 10 when contracted, and expands in a planar manner so as to be in close contact with the lower surface of the deck when inflated.

As shown in FIGS. 1 and 2, the first embodiment of the present invention
According to the method, a plurality of hollow elastic bags 12 are inserted from a plurality of hollow tubes 10 into the lower surface of the deck, and then compressed gas is supplied into each hollow elastic bag 12 via a tube 12a to expand the hollow elastic bags 12. Draft 8 by increasing the buoyancy of the floating roof 7
a is lowered to the bottom of the deck. According to this method, the existing roof support or the hollow tube 10 provided separately is used,
A plurality of hollow elastic bags 12 (balloons) are inserted into the lower surface of the deck,
By supplying compressed gas into each hollow elastic bag 12 and expanding it, the buoyancy can be increased to the lower surface side of the floating roof and the draft 8a can be reduced, and the outflow of the contents onto the deck is completely stopped. Can be repaired.

FIG. 3 is a diagram schematically showing a second method of the present invention. As shown in this figure, the hollow elastic bag 12 is inserted into the lower surface of the deck having the through portion 9 through the hollow tube 10 adjacent to the deck through portion 9, and then the compressed gas is supplied into the hollow elastic bag 12 to expand the hollow elastic bag 12. Then, the through-hole 9 is brought into close contact with the lower surface of the deck, thereby sealing the through-hole from the lower surface of the deck.

According to this method, one or a small number of hollow elastic bags 12 are inserted into the lower surface of the deck from the roof support portion near the penetrating portion 9 (damaged portion), and are expanded to penetrate the penetrating portion 9.
The through-hole 9 is sealed from the lower surface of the deck by being in close contact with the lower surface of the surrounding deck, and can be repaired in a state where the outflow of the contents is prevented. The first method and the second method may be performed separately, or both may be used in combination. In addition, repair of the deck is a method without the risk of ignition of the contents, for example,
It is preferable to use cement, adhesive, putty, or the like. Further, the above description has been made mainly on a single deck, but the same can be applied to a lower deck of a double deck type.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the spirit of the present invention.

[0021]

As described above, the method for repairing a deck of a floating roof type storage tank according to the present invention uses the floating roof type storage tank even if a penetration part having a size that cannot be stopped by putty or the like is generated. Without stopping, it has an excellent effect that the outflow thereof can be prevented and the penetration part of the deck can be safely repaired.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing the method of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a diagram schematically showing another method of the present invention.

FIG. 4 is a schematic view of a floating roof type storage tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Foundation 2 Side plate 3 Deck 4 Pontoon 5 Sealing device 6 Weather shield 7 Floating roof 8 Contents 8a Draft 9 Penetration part 10 Hollow tube 11 Lid 12 Hollow elastic bag (balloon) 12a Gas supply tube

Claims (3)

[Claims] 1. A plurality of hollow tubes extending vertically in a direction penetrating a deck and having an upper end located above a draft, are dispersed and attached to the deck surface in advance in a watertight manner, and a hollow elastic bag is inserted through the hollow tubes. Into the underside of the deck,
Next, a compressed gas is supplied into the hollow elastic bag and expanded.
A method for repairing a deck of a floating roof type storage tank. 2. A plurality of hollow elastic bags are inserted into the lower surface of the deck from a plurality of hollow tubes, respectively, and compressed gas is supplied into each hollow elastic bag to expand the hollow elastic bags, thereby increasing the buoyancy of the floating roof and drafting. 2. The deck repair method for a floating roof type storage tank according to claim 1, wherein the height of the storage tank is lowered to a lower surface of the deck. 3. Inserting a hollow elastic bag into a lower surface of a deck having a penetrating portion through a hollow tube adjacent to the deck penetrating portion, and then supplying compressed gas into the hollow elastic bag to inflate the deck to surround the penetrating portion. The deck repair method for a floating roof type storage tank according to claim 1, wherein the deck is adhered to the lower surface, whereby the penetration portion is sealed from the lower surface of the deck.