JPH0332378Y2 - - Google Patents

Description

[Detailed description of the invention] <Technical field> This invention relates to a foam fire extinguishing system in which a foam generator is installed at the top of a dike such as an oil or LNG storage tank to suppress or extinguish fires within the dike. be.

<Prior art> A foam generator is installed at the top of the dike of an oil storage tank or LNG tank, and the foam is piled up to a certain height inside the dike to gasify oil or LNG leaked from inside the tank. were suppressed and extinguished the fire.

<Problems with conventional technology> On the other hand, in recent years, the width between the tank and the dike has been narrowed from the perspective of effective site utilization, and the height has been reduced by 50%.
The height was from ~8m to 10-15m. However, when the dike becomes high like this, the inside of the dike becomes 10~
An upward wind of 15 m/sec was generated, and the foam from the foam generator was scattered before it reached the bottom of the dike, making it impossible to suppress vaporization and extinguish the fire.

<Means for solving the problem> In view of the above points, this idea is based on a foam generator installed at the top of a dike such as an oil storage tank.
The foam fire extinguishing device has a foam discharge port connected to a foam chute provided vertically facing the surface of the dike.

<Function> Even if a blowing wind of 10 to 15 m/sec occurs inside the dike, the foam outlet faces the dike surface and does not face directly into the direction of the wind blowing. The foam falls through the foam chute without being picked up by the wind and is released from the outlet.

<Example> The figure shows an embodiment of the foam fire extinguishing system of this invention, in which 1 is a storage tank in which a heat-generating liquid such as petroleum or LNG is stored, 2 is a liquid barrier installed around the tank, and 3 is a foam fire extinguishing system. The foam generator is installed at the top of the dike 2 and is of a water wheel type or an aspiration type. Reference numeral 4 denotes a foam chute connected to the foam generator 3, which consists of a cylinder 5 with a U-shaped cross section extending to the bottom of the dike 2, and its opening side faces the dike surface and has a foam discharge port 6. Configure. A plurality of return plates 7 are provided facing downward at intervals on the side of the foam discharge port 6, and are provided so that the foam generated from the foam generator 3 descends smoothly within the chute 4. Further, 8 is a water pump, 9 and 10 are gate valves, 11 is a foam stock solution tank, and 12 is a foam mixer.

Next, the action of the foam fire extinguishing system of this invention will be explained.

When a gas detector or a flame detector (not shown) detects that the heatable liquid has leaked from the storage tank 1, the water pump 8 is activated and the foam mixer 12 collects foam from the foam stock tank 11. The stock solution is mixed with pressurized water in a predetermined ratio and sent to the foam generator 3. Then, the foam generated in the foam generator 3 falls down the foam chute 4, but at that time, the foam returns to the plate 7.
Due to this action, the foam descends along the inner wall of the foam chute 4 while being prevented from scattering and reaches the leakage surface, and highly foamed foam is released from the discharge port 6, and the foam is layered on the leakage surface, suppressing the vaporization of the heat-generating liquid. or extinguished.

Under the above conditions, within the dike 10~
Even if an upward wind of 15 m/sec occurs, the bubbles will be affected by the wind because the bubble outlet 6 faces the surface of the dike 2 and does not directly face the direction in which the wind blows. The foam descends through the bubble chute 4 without any trouble.

<Effects> The foam fire extinguishing system of this invention is constructed and operates as described above, so even if a strong blowing wind occurs inside the dike, the foam will descend inside the foam chute without being blown up by the wind. This has the effect of providing a foam fire extinguishing system for petroleum storage tanks and the like that can release foam from the outlet just above the flammable liquid level.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the foam fire extinguishing device of this invention, and FIG. 2 is a perspective view of the main parts of FIG. 1. 1... Storage tank, 2... Dike, 3... Foam generator, 4... Foam chute, 5... Cylindrical body, 6... Foam outlet, 7... Return plate, 8... Water pump ,9,
10...Gate valve, 11...Foam stock solution tank, 12...
...foam mixer.

Claims (1)

[Scope of utility model registration request] An oil storage tank characterized in that a foam chute, the foam discharge port of which is installed in the vertical direction facing the surface of the dike, is connected to a foam generator installed at the top of a dike such as an oil storage tank. Fire extinguishing equipment such as.