JPS5938150B2 - Floating roof balancing device for tank earthquake resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a floating roof balancing device for a cylindrical floating roof tank.

Generally, cylindrical floating roof tanks are widely used to store large amounts of crude oil, refined petroleum, etc.

Conventional tanks of this type have been constructed as shown in FIGS. 1 and 2. That is, a tank 1 shown in FIG. 1 has a floating roof 3 having an annular floating pontoon 2, and a seal 4 is disposed between the pontoon 2 and the tank 1. The example shown in FIG. 2 is a so-called double-deck cylindrical tank having a double-deck floating roof 5.

In the cylindrical tank configured as described above, the floating roof rises and falls according to the increase and decrease of the liquid 6 such as crude oil, but the floating roof rises and falls according to the fluctuation of the free surface of the liquid 6 due to sloshing during an earthquake. If the floating roof is tilted, liquid may leak from the gap between the tank and the inner wall, or the floating roof may be destroyed and liquid may leak, causing an oil overflow accident.

SUMMARY OF THE INVENTION An object of the present invention is to provide an earthquake-resistant floating roof balance maintaining device for a tank, which is configured to attenuate sloshing energy generated during an earthquake and prevent the floating roof from being destroyed.

Hereinafter, details of the present invention will be explained along with embodiments shown in the drawings.

FIG. 3 and subsequent figures illustrate one embodiment of the present invention, and the same or corresponding parts as in FIGS. 1 and 2 are designated by the same reference numerals.

What is indicated by the symbol T in the figure is a pulley suspended from a support frame 8 protruding from the upper end of the tank 1, and between this pulley and the pontoon 2 there is a wire 9 as shown by the solid line in FIG. is suspended via a damper 10 with a spring.

After this wire 9 is attached to a pulley T, it is guided downward along the inner surface of the tank 1, and is passed through pulleys 12, 12 fixed to the end of the bottom plate 11 of the tank 1 to the pontoon 2 on the opposite side. is connected to the bottom of the On the other hand, a wire 13 shown in chain lines in FIG. 6 is stretched between the pulley 7 and the pontoon 2, which are disposed opposite to each other with the center interposed therebetween, via a damper 10 with a spring.

After the wire 13 is attached to the pulley 7, it is guided downward along the wall of the tantalum 1 and connected to the back side of the pontoon 2 on the opposite side along the pulley 12, 12. That is,
The floating roof 3 has a pair of wires 9 on the same diameter.
．． 13 to suppress displacement of the other side of the floating roof relative to each other and to maintain a balanced state. A plurality of such pairs of wires are installed, and as is clear from the plan view in Figure 3, they are installed at equal angular intervals, and the angle θ between adjacent wires is 90 degrees. It is necessary that the following is true.

If the angle is 90 degrees or more, a rotation axis around which the floating roof position tilts will inevitably occur, and the effect of adopting the above structure will be significantly diminished.

On the other hand, the spring-equipped damper 10 is constructed as shown in FIGS. 4 and 5.

That is, the spring-equipped damper 10 includes an oil damper 14, a support plate 16 is fixed to the piston rod 15 side, a support plate 17 is fixed to the cylinder side, and a spring 18 is stretched between the two. Since this embodiment is configured as described above, as the amount of liquid 6 to be stored increases or decreases,
Since there is a constant relationship between the distance x from the pontoon to the pulley and the distance y from the pontoon to the bottom plate (x+y), and the total length of the wire is also constant, the floating roof 3 will remain in an equilibrium state when it goes underground. do.

However, when a floating roof tries to tilt due to sloshing caused by an earthquake, the other wire is always pulled out of a pair of wires set along the same route, increasing the tension and suppressing the floating roof from tilting.

At the same time, the spring-loaded damper 10 works, and part of the sloshing energy is consumed. Incidentally, as the floating roof tilts, the tension in one of the wires increases, which acts as a restoring force for the floating roof. At this time, the impact caused by the sudden increase in the tension of the wire is caused by the relative displacement of the spring-equipped damper 10. This can prevent the floating roof 3, pulley 7, etc. from being destroyed. Further, here, the action of the spring 18 of the spring-equipped damper 10 is as follows. That is, the spring 18 is stretched between the support plates 16 and 17 with some tension applied thereto.

Therefore, when the floating roof 3 tilts, the spring 18 on the lower side is stretched, and when the floating roof is restored by the restoring action of the wire as described above, the stretched spring moves the oil damper 14 due to its own tensile force. is returned to the neutral position to attenuate some of the sloshing energy and wait for a similar effect on the next tilting of the floating roof.
As is clear from the above description, the present invention has the following effects.

(1) Since two sets of wires are stretched on the same diameter from the upper surface of one side of the floating roof to the lower surface of the other side, when the floating roof is tilted, the tilting is always restored. This can keep the floating roof in equilibrium.

(2) Since a damper with a spring is interposed in each wire, a sudden increase in the tension of the wire can be alleviated, and the oil damper can be quickly restored.

(3) Due to the presence of the spring-equipped wire, the impact applied to the floating roof is weakened, and damage to the floating roof, pulley, etc. can be prevented.

(4) Since the floating roof is always in contact with the liquid surface and has the function of trying to maintain an equilibrium state, it suppresses fluctuations in the free liquid level of the stored liquid and has a large damping effect on the vibration system consisting of the floating roof and free liquid.
Can prevent liquid leakage.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal sectional side views of a conventional floating roof tank, FIGS. 3 to 6 illustrate an embodiment of the present invention, and FIG. 3 is a plan view, and FIGS. 5 is a plan view and a vertical side view of the damper with a spring, and FIG. 6 is a vertical side view of FIG. 3. 1...tank, 2...pontoon, 3
...Floating roof, 7...Pulley, 9...
...Wire, 10...Damper with spring.

Claims (1)

[Claims] 1. In a cylindrical floating roof tank that has a floating roof that rises and falls in accordance with the liquid level, a plurality of pairs of wires each consisting of two wires are arranged at equal angular intervals, and one of the pair of wires is connected to the floating roof. It is guided downward from the top of the roof via a damper with a spring attached to a pulley attached to the top of the tank.
Furthermore, it is fixed to the lower surface of the floating roof on the opposite side along the tank bottom plate on the same diameter, and the other wire is similarly connected to the tank via a damper with a spring from the upper surface of the floating roof on the opposite side to the one wire. 1. A floating roof balance maintaining device for earthquake resistance of a tank, characterized in that the device is guided along the wall surface and the bottom surface and is fixed to the lower surface of the floating roof at a position opposite to the starting point of the one wire.