JP2005247420A - Apparatus for preventing sloshing in floating roof tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent breakage or sinking of a floating roof and an outflow of a liquid in a tank to the upper part of the floating roof or an overflow to the outside of the tank, by restraining a shake of the floating roof before it becomes big, when intense sloshings are produced by a long-cycle shake at an earthquake in a floating roof tank. <P>SOLUTION: In the floating roof tank, two or more supports are provided in an equal angle from the center of the tank over the whole circumference of the inside of the tank body, and the supports are fixed to the upper part of the sidewall of the tank body and the bottom part of the tank and holes for penetrating the supports provided on the floating cover to make the supports penetrate the holes so that the floating roof can be pressed by the supports, when the floating roof is shaken by a sloshing. As a result, the floating roof can move only in a limited distance from the horizontal position so that the liquid in the tank cannot become large waves (kinetic energy). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to prevention of sloshing in a floating roof tank.

In the invention for sloshing calming of the conventional floating roof type tank, there is one in which a filament with a resistance plate is suspended on the floating roof. (See Patent Document 1)
JP-A-9-142575

Long-period shaking during an earthquake can cause severe sloshing of the liquid in the floating roof tank and cause major disasters such as the occurrence of tank fires due to breakage or sinking of the floating roof.

The conventional anti-sloshing measures for floating roof tanks are based on the liquid level fluctuation calculation based on the Fire Service Law, and set the upper limit liquid level, which is the upper limit of liquid injection, to ensure the necessary space distance. Although measures against overflow are taken, it does not deal with severe sloshing due to long-period shaking during earthquakes at any liquid level.

For this reason, even in situations where severe sloshing occurs due to long-period shaking during an earthquake, the floating roof is prevented from breaking or sinking, or the liquid flowing out to the top of the floating roof or overflowing outside the tank. Measures that can be done are necessary.

Even in situations where intense sloshing occurs, the liquid wave (kinetic energy) in the tank is small in the initial stage of sloshing, but the liquid vibration in the tank amplifies over time, and the wave (kinetic energy) It will be extremely large.

Therefore, in order to effectively prevent the occurrence of severe sloshing, it is necessary to take measures to prevent this at the initial stage of occurrence of sloshing where the wave (kinetic energy) of the liquid in the tank is still relatively small.

As the invention of the anti-sloshing method, there is the above-mentioned “background art”, which is intended to calm down in the stage of amplification of the shaking of the sloshing, and the “problem to be solved” is also a sealing device. And it is mainly to prevent damage to the weather shield.

The present invention prevents the sloshing of a floating roof tank that can prevent severe sloshing caused by long-period shaking particularly during an earthquake at an early stage where the wave (kinetic energy) of the liquid in the tank is still small. The object is to provide a device.

In a floating roof type tank, a plurality of support posts are provided at equal angles from the center of the tank on the entire inner circumference of the tank body, and these support posts are fixed to the top of the tank body side wall and the bottom of the tank, and to the floating roof. It was configured so that when the floating roof swings during sloshing, the swing of the floating roof can be suppressed by the support by providing a hole for penetrating the column and allowing the column to pass through the hole for penetrating the floating roof. It is characterized by.

In this way, in swinging where one of the floating roofs rises and the other side descends during sloshing, the floating roof is pressed by the support pillars all around, so it moves only within a limited distance from the horizontal position. The liquid in the tank cannot be a large wave (kinetic energy). That is, this can be prevented at an early stage of sloshing.

By providing a stress device that is a trapezoidal structure around the top and bottom of the column penetration hole of the floating roof through which the column from the tank body penetrates, the swinging of the floating roof is further reduced. , Disperse the acting force (load) on the support of the floating roof.

According to the anti-sloshing device for a floating roof type tank of the present invention, the floating roof is supported by the support of the entire circumference regardless of the direction in which swinging occurs such that one side of the floating roof rises and the other side descends during sloshing Since it is pressed, it can move only within a limited distance from the horizontal position of the floating roof, and the liquid in the tank cannot become a large wave (kinetic energy). That is, this can be prevented at an early stage of sloshing.

As a result, breakage or sinking of the floating roof, as well as spilling of liquid in the tank to the upper part of the floating roof or overflowing to the outside of the tank can be prevented. Can be prevented.

By providing a stress device that is a trapezoidal structure around the top and bottom of the column penetration hole of the floating roof through which the column from the tank body penetrates, the swinging of the floating roof can be further reduced. And the acting force (load) on the support of the floating roof can be dispersed.

The present invention functions only when the floating roof swings when sloshing occurs. When the floating roof, which is a normal case, is horizontal, the floating roof can move smoothly along the support column.

As shown in FIGS. 1 and 2, a plurality of support columns 3 are provided at equal angles from the center of the tank on the entire inner periphery of the tank body 1, and the upper side of the support column 3 is supported by a support column support plate 4 on the side plate 2 of the tank body. The lower part is fixed to the bottom of the tank body.

The position of the support column 3 is most effective at a position close to the side plate 2 as much as possible from the viewpoint of suppressing the wave of sloshing (kinetic energy). However, since an actual floating roof has a pontoon (air chamber for floating the floating roof) on the outer periphery, the position is determined in consideration of the strength of the floating roof.

The required number and size (diameter, etc.) of the columns 3, the strength of the column support plate 4, and the fixing procedure thereof are determined by the magnitude of the acting force (load) applied to each structure by sloshing. Further, when there is a problem in strength at the side plate 2 and the tank bottom, a part of the side plate 2 and the tank bottom is reinforced.

3 and FIG. 4 is provided in the floating roof 5, and a cone as shown in FIGS. 1 and 3 is formed around the upper and lower portions of the support hole 9. A stress device 6 which is a trapezoidal structure is provided.

In terms of the shape of the stress device 6, the theoretically the higher the height, the smaller the swing of the floating roof 5 can be suppressed, but the operation of the floating roof tank (the upper limit of liquid injection and the lower limit of use) ), Etc., and make it as high as possible. Also, the dimensions of the bottom and top sides of the cone as a trapezoid are determined by the magnitude of the acting force (load) on the stress device 6. Furthermore, when the floating roof 5 itself has a problem in strength, a part of the floating roof is reinforced.

As shown in FIG. 3, a packing is provided in the stress device 6 which is a structure having a cone-shaped trapezoid. While acting as a buffer when an acting force (load) is applied between the support column 3 and the stress device 6, the generation of sparks due to friction between metals is prevented.

The shorter the distance between the stress device 6 of the floating roof 6 and the column 3 is, the smaller the swing of the floating roof 5 can be, but it is necessary to provide the stress device packing 10 shown in FIG. The distance between the gaps is made as short as possible while considering the relationship between the strength of the packing and the thickness based on the elasticity.

The portion of the stress device 6 where the stress device packing 10 is provided is provided with a taper in order to disperse the acting force (load) from the floating roof 5 caused by rocking during sloshing. Theoretically, the angle of the taper is the same as the maximum inclination angle of the floating roof caused by rocking during sloshing, so that the acting force (load) caused by rocking can be most effectively dispersed.

Further, as the stress device 6 is tapered, the stress device packing 10 is provided with a taper opposite to that of the stress device 6 as shown in FIG. By making the surface portion parallel to the column, it is possible to effectively receive the acting force (load).

As shown in FIG. 3, a floating roof stress packing 11 similar to the stress device packing 10 is also provided around the column penetration hole 9 of the floating roof. When an unexpected situation such as breakage of the stress device 6 occurs, the floating roof 5 suppresses the swing and prevents the occurrence of sparks due to friction between metals.

The stress device packing 10 and the floating roof stress packing 11 shown in FIG. 3 have a low elasticity to suppress the swing to a smaller level, can withstand a large acting force (load), and do not generate a spark against friction. For example, hard rubber is used.

The liquid packing 12 shown in FIG. 3 is provided with a seal that is currently used on the outer periphery of the floating roof.

It is sectional drawing which shows an example of the form of this invention. It is a top view of FIG. FIG. 3 is an arrow view in the AB direction of FIG. 2. FIG. 4 is an arrow view in the CD direction of FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tank main body 2 Side plate 3 Support column 4 Support column support plate 5 Floating roof 6 Stress device 7 Seal 8 Liquid 9 Strut hole 10 Stress device packing 11 Floating roof stress packing 12 Liquid packing

Claims (2)

In a floating roof type tank, a plurality of support posts are provided at equal angles from the center of the tank on the entire inner circumference of the tank body, and these support posts are fixed to the top of the tank body side wall and the bottom of the tank, and to the floating roof. By providing a hole for penetrating the pillar and penetrating the pillar through the hole for penetrating the floating roof, when the floating roof swings when sloshing occurs, the swing of the floating roof is suppressed by the pillar. An anti-sloshing device for a floating roof tank. 2. The floating roof according to claim 1, wherein a stress device, which is a structure having a cone-shaped trapezoid, is provided around an upper part and a lower part of a pillar penetration hole of a floating roof through which a pillar from a tank body penetrates. Type anti-sloshing device.

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