JP2007290774A - Device for preventing liquid tank floating roof from swinging - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a liquid tank floating roof from swinging due to an earthquake, etc., and the floating roof or the liquid tank from consequently undergoing serious damage thereto, and to prevent liquid in storage from leaking through the clearance between the wall of the liquid tank and the floating roof, which is required for the floating roof to move up and down, thus preventing the occurrence of fire, etc., of a flammable liquid. <P>SOLUTION: A flexible locking membrane 14 having sufficient strength is mounted by using a mounting tool 13, into a gap between the outer periphery of the floating portion of the floating roof and the wall of the liquid storage tank, the locking membrane including a pressurizing tube 15 built therein, since the pressurizing tube is normally contracted but expanded when in operation. In operation, a high-pressure gas is supplied to the pressurizing tube 15 for expansion so that the floating roof is fastened to the wall of the liquid tank and the stored liquid is tightly enclosed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus for preventing a liquid tank floating roof from swinging, which is likely to occur due to an earthquake or the like, and at the same time preventing leakage of stored liquid.

  Conventional floating roof swing prevention devices do not completely stop vertical and horizontal motions, but mainly consist of shock absorbers and vibration control devices that soften the swings or reduce the collision between the float and the liquid tank wall. It was.

  The conventional floating roof rocking | fluctuation prevention apparatus tries to improve seismic resistance, leaving the function which a floating roof raises / lowers the inside of a liquid tank according to the change of the storage amount of a stored liquid. If strong vibrations occur, this method inevitably causes ups and downs and horizontal movements of the floating roof due to the waves generated on the liquid level of the stored liquid, causing enormous damage to the structure of the floating roof and liquid tank. . Furthermore, there is a possibility that the stored liquid leaks through the gap between the liquid tank wall and the floating roof, which is used to move the floating roof up and down. It was insufficient. It is an object to prevent such a floating roof and a liquid tank from being damaged, and at the same time, prevent a stored liquid from leaking to prevent a fire of a flammable liquid.

  The structure of a general floating roof is called a float or pontoon inside the liquid tank, and it is not necessarily integrated as a whole, but a donut-shaped float made of steel or the like having a hollow inside is arranged, It has a structure where the hole in the center of the donut is closed with a single or double lid. The floating roof floats on the stored liquid level while maintaining a certain gap with the liquid tank wall so that it can move freely in the vertical direction according to the amount of stored liquid. The present invention is an apparatus having a function of completely closing the gap between the liquid tank wall and the floating roof to fix the floating roof and preventing the stored liquid from leaking outside.

  First, the structure of the present invention of claim 1 will be described. FIG. 1 is a cross-sectional view of a float portion of a liquid tank wall and a floating roof. The present invention is composed of three main parts: 13 fixtures, 14 fixed membranes, and 15 pressure tubes. Since the 14 fixed membrane fixes the entire floating roof to the 11 liquid tank wall, it must be flexible but have sufficient tensile strength. For example, the surface of a fiber woven fabric with sufficient tensile strength, such as tires for bicycles and automobiles, is made of rubber, synthetic resin, etc., and the floating roof withstands the expanding pressure of 15 pressure tubes As a whole, it must have enough tensile strength to transmit the rocking force to the liquid tank wall. Also, it must have a flat outer shape that usually fits in the gap between the liquid tank wall and the float.

  15 Pressurized tube is supplied with a gas that does not react with stored liquid such as nitrogen gas or carbon dioxide gas and does not easily cause a fire, etc., and is pressurized and expanded between the floating roof and the liquid tank wall to strengthen the 14 fixed membrane 11 Press against the liquid tank wall, and the entire floating roof is fixed to the liquid tank wall by the frictional force. The 13 fixture is made of metal, synthetic resin or the like, and the 14 fixing film is fixed to the 12 float with a bolt or the like. The 13 fixture does not necessarily have the form as shown in this figure, and may be any structure as long as the 14 fixing membrane can be fixed to the 12 float. And the apparatus of such a structure is attached to the whole circumference of 12 floats without a gap.

  FIG. 2 shows a state in which a pressurizing gas is supplied to a 15 pressurizing tube and the entire floating roof is fixed to the liquid tank wall. The 15 pressurizing tube that is pressurized and expanded does not necessarily have to be integrated with the entire circumference of the float, but rather may be divided in consideration of safety. The 14 fixed membrane and the 13 fixture need to be continuously integrated with each other in order to maintain sufficient airtightness to prevent leakage of the stored liquid.

  In the state where the present apparatus is operating as shown in FIG. 2, the floating roof is fixed, so that it does not swing even if it receives vibration. Further, even if waves are likely to occur on the 16-stored liquid level, the liquid level rises up to the lower end of the apparatus and the partial internal pressure of the liquid increases and decreases, and no actual wave is generated. No accumulation or wave synthesis occurs, so no sloshing phenomenon occurs. Further, the internal pressure of the stored liquid decreases at one end and increases at the other end, but does not leak to the outside due to the airtightness of the apparatus.

  The expansion gas supplied to the 15 pressurized tube must be supplied in the specified amount in a short time before the vibration wave such as an earthquake arrives, so it is usually stored in a cylinder with high pressure or liquid. .

It is sectional drawing of the float part of a liquid tank wall and a floating roof. It is sectional drawing which this apparatus has act | operated by the float part of the liquid tank wall and the floating roof.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Liquid tank wall 12 Float 13 Attachment 14 Fixed film 15 Pressurizing tube 16 Liquid storage liquid

Claims (1)

  The invention of a liquid tank floating roof swing prevention device is a liquid tank in which a floating tube is built in a gap between the outer periphery of the float part of the floating roof and the storage tank wall, which normally has a reduced pressure but expands during operation. It is a device with a flexible fixing membrane attached to the wall and strong enough to seal the stored liquid.

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