JPH0826388A - Apparatus for preventing liquid in container from sloshing - Google Patents

Abstract

PURPOSE:To prevent liquid in a container from slashing at the time of an earthquake or the like. CONSTITUTION:Compressed air is sent by a pneumatic valve 8, which is opened/ closed by a signal from a controller 6 for receiving a signal of a pressure sensor 5, from a compressed air source 7 into a bag 4 placed in a container 1 above a liquid level A of liquid 2 with a face in contact with the container 1 fixed to the container 1, so as to keep inside of the bag 4 at a predetermined pressure, and by applying pressure to the liquid level A via the bag 4, a number of sloshing vibrations is increased no prevent resonance with an earthquake or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing sloshing of a liquid in a container such as an oil storage tank or a water tank.

[0002]

2. Description of the Related Art When a container containing a liquid is shaken by an earthquake wave or the like, a large wave is generated on the surface of the liquid, and a sloshing phenomenon occurs in which the large wave hits the wall surface of the container. In particular, when the natural frequency determined by the liquid and the container and the frequency of an earthquake or the like that causes the vibration to coincide with each other, violent sloshing may occur and the container may be damaged.

Therefore, conventionally, a strong container that is not damaged even if sloshing occurs has been required. In addition, there is also seen an example in which a partition plate in the container is conventionally installed to suppress sloshing.

FIG. 5 shows that when a liquid 2 is contained in the conventional container 1, an earthquake occurs, the liquid 2 causes sloshing, the liquid surface A changes to A _3, and an impact force is applied in one direction of the container 1. Shows the situation where is added.

FIG. 6 shows a conventional example in which a partition plate 10 having a communication hole 10a is installed in the container 1 to suppress sloshing. In this example, the liquid level A of the liquid 2 at the time of an earthquake is the liquid level A ₄
Shows the sloshing situation.

[0006]

5 and 6 are for attenuating the sloshing that has occurred on the wall surface of the container, and the one shown in FIG. 6 is compared with the one shown in FIG. Sloshing can be mitigated, but it does not prevent its occurrence. For this reason, the conventional container 1 must be made strong so that the occurrence of sloshing is predicted, and there is a problem that the manufacturing cost becomes high.

The present invention is intended to provide a device for preventing sloshing of a liquid in a container which can solve the above problems.

[0008]

A device for preventing sloshing of a liquid in a container according to the present invention is an expansion / contraction device in which a surface other than the surface on the liquid side, which is in contact with the container, is fixed in the upper part of the container above the liquid surface of the liquid. Flexible bag, a pressure detector for detecting the pressure in the bag, a gas supply pipe having a gas valve connected to the pressure gas source and the bag, and opening and closing the gas valve by receiving a signal from the pressure detector. It is characterized by having a controller for outputting a signal.

[0009]

The relationship between the sloshing frequency of the liquid and the tension of the film when pressure is applied to the liquid surface of the liquid in the container through the film,
As shown in FIG. FIG. 7 shows that the sloshing frequency of the liquid can be increased by increasing the film tension.

In the present invention, the controller outputs the signal for opening and closing the gas valve of the gas supply pipe in response to the signal from the pressure detector in the elastic bag. Pressure gas is supplied and the gas pressure in the bag is maintained at a predetermined value.

Since the surface of the elastic bag which is in contact with the container other than the liquid side surface is fixed to the container, the bag bulges when pressure gas is supplied to the liquid surface of the liquid in the container. As they come into contact with each other, tension is generated in the bag. Therefore, as shown in FIG. 7, the sloshing frequency of the liquid in the container rises according to the tension generated in the bag, and resonance with external force due to an earthquake or the like is avoided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. The liquid 2 is contained in a container 1 having a rectangular horizontal cross section. An elastic bag 4 made of a film of rubber or the like in the gap between the container 1 formed in the upper part of the container 1 and the liquid surface A of the liquid 2.
Are arranged, and the upper and side surfaces of the bag 4 that contact the container 1 other than the surface on the liquid 2 side are fixed to the inner surface of the container 1. The pressure of the air 3 in the elastic bag 4 is detected by the pressure detector 5, and its signal is transmitted to the controller 6. The pressure air source 7 is connected to the inside of the bag 4 by an air supply pipe 9, and the controller 6 is connected to the air supply pipe 9.
Is provided with an air valve 8 that opens and closes according to the signal.

In the present embodiment, when the air valve 8 is open, the pressure air is sent from the pressure air source 7 through the air supply pipe 9 into the elastic bag 4. The pressure of the air 3 in the bag 4 is detected by the pressure detector 5, the signal is sent to the controller 6, and the air valve 8 is opened / closed by the signal of the controller 6, so that the air pressure in the bag 4 is a predetermined value. Held in.

FIG. 2 shows a state in which the air pressure in the elastic bag 4 reaches a predetermined value, and the bag 4 bulges due to the air pressure and comes into contact with the liquid surface A of the liquid 2 in the container 1. do it,
Tension is generated in the bag 4.

FIG. 3 shows a state in which the container 1 in the state shown in FIG. 2 is shaken by an earthquake and the liquid level A of the liquid 2 in the container 1 changes to A _1, and the bag 4 changes in the liquid level. I am following. The height of the liquid surface is pressed by the force of the bag 4 so that the height of the liquid surface is lowered by the tension of the bag 4.

FIG. 4 shows a state in which the shaking of the earthquake is great and a portion of the bag 4 that cannot follow the change in the liquid level is generated. When the liquid level A of the liquid 2 in the container 1 becomes fluctuation is large A _2, cavities generated between the part and the bag 4 which is liquid surface A ₂ fell significantly. Air pressure does not act on the liquid surface of this cavity, and the air pressure P acts only on the portion where the liquid surface rises, and the force to stop the rise of the liquid surface is not only the tension of the bag 4 but also the inside of the bag 4. The air pressure P is applied, and the force becomes very large.

As described above, as shown in FIGS. 3 and 4, when the container is shaken by an earthquake, the liquid level of the liquid 2 in the container 1 is passed through the elastic bag 4 through the elastic bag 4. The air pressure in the bag 4 acts on the liquid surface of the liquid 2 while the pressure is applied to the liquid. As described with reference to FIG. 7, when pressure is applied to the liquid surface of the liquid 2 in the container 1 through the elastic bag 4, the tension of the bag 4 is increased to increase the sloshing vibration of the liquid 2 in the container 1. The number can be increased. In this embodiment, the tension of the bag 4 can be increased by maintaining the air pressure in the bag 4 at a predetermined value as described above, and the liquid 2 determined by the container 1 and the liquid 2 can be increased.
It is possible to prevent the resonance with the vibration of the earthquake by sufficiently increasing the sloshing frequency of. In addition to this, the rise of the liquid level of the liquid in the container 1 can be suppressed by the air pressure in the bag 4.

In the above embodiment, the air pressure is constantly applied to the liquid surface A of the liquid 2 in the container 1,
It is also possible to add a mechanism to open the air valve 8 and to inject the pressurized air into the bag 4 in a short time only when the sway of a predetermined amount or more is detected in the above embodiment. In this case, since it is necessary to raise the air pressure in the bag 4 to a predetermined pressure in a short time, it is necessary to upsize the pressurized air supply device.

Further, in the above embodiment, the pressure air is introduced into the bag 4, but it goes without saying that another pressure gas can be introduced into the bag 4.

[0020]

According to the present invention, the pressure of the compressed gas in the elastic bag, which is disposed in the upper part of the container above the liquid surface of the liquid and whose surface other than the surface on the liquid side which is in contact with the container is fixed to the container, By maintaining the value at a predetermined value, it is possible to prevent the sloshing phenomenon that damages the container due to an earthquake or the like. Thereby, the design standard of the container can be lowered and the manufacturing cost of the container can be reduced.

[Brief description of drawings]

FIG. 1 is an overall view of an embodiment of the present invention.

FIG. 2 is an explanatory view showing a state in which the air pressure in the bag reaches a predetermined value in the same example.

FIG. 3 is an explanatory diagram showing a state in which the shaking of an earthquake is working in the embodiment.

FIG. 4 is an explanatory diagram showing a state in the case where the shaking of an earthquake is large and a portion of the bag that cannot follow a change in the liquid level is generated in the embodiment.

FIG. 5 is an explanatory diagram showing a state of a conventional container when an earthquake occurs.

FIG. 6 is an explanatory view showing a state of a conventional container having a partition plate when an earthquake occurs.

FIG. 7 is a relationship diagram between sloshing frequency and film tension.

[Explanation of symbols]

1 container 2 liquid 3 pressure air 4 elastic bag 5 pressure / detector 6 controller 7 pressure air source 8 air valve 9 air supply pipe A liquid level of liquid in container A _{1 to} A ₄ container when shaken by earthquake Liquid level inside

Claims (1)

[Claims] 1. An elastic bag, which is disposed in the upper part of the container above the liquid surface of the liquid and has a fixed surface other than the liquid-side surface that contacts the container, a pressure detector for detecting the pressure in the bag, Liquid in a container, comprising a gas supply pipe having a gas valve connected to a pressure gas source and the inside of the bag, and a controller for receiving a signal from the pressure detector and outputting an opening / closing signal to the gas valve. Anti-sloshing device.