JP2008245933A - High expansion foam fire-extinguishing apparatus and foaming method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent reduction of the foam volume ratio in high expansion foam fire-extinguishing apparatus. <P>SOLUTION: In the high expansion foam fire-extinguishing apparatus, air in an emission section 1 is sucked into a flow passage tube 2 with a built-in emission nozzle 9, and an aqueous solution w emitted from the emission nozzle 9 is made to collide with a foaming net 7 to foam. An air mixer 10 is mounted on an aqueous solution supply pipe 8 of the emission nozzle 9 to mix the aqueous solution w with air k to prepare air-liquid mixed fluid wk. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a high expansion foam fire extinguishing equipment and a foaming method thereof used in oil tank pits, oil complex culverts, cabins, holdhouses, and the like. The present invention relates to an expanded foam fire extinguishing equipment and a foaming method thereof.

  In the foam fire extinguishing equipment, an aqueous foam solution (hereinafter sometimes simply referred to as an “aqueous solution”) is discharged from a radiating nozzle, and the foam is blown by colliding with a foaming net and sucking in air. Filled and extinguishing suffocation. The foam fire extinguishing equipment includes a low foaming fire extinguishing equipment and a high foaming (high expansion foam) fire extinguishing equipment.

  In both the fire extinguishing equipments, the foaming ratio is different, for example, the foaming ratio of the low foaming fire extinguishing equipment is 20 or less, and the foaming ratio of the high expansion foam fire extinguishing equipment is 80 or more and less than 1000. Here, the expansion ratio refers to the volume ratio between the aqueous foam solution and the generated foam.

  In order to generate highly expanded bubbles, for example, bubbles with an expansion ratio of 500 or more, it is necessary to take in a large amount of air from the upstream side of the radiation nozzle. The method (called “outside air”) is generally used.

  However, in this outside air, since outside air is used, a duct is penetrated in the building, or a bubble generator is provided by making a hole in the partition wall. .

  Therefore, in order to solve the above problem, a high-expansion foam fire extinguishing equipment of a system (referred to as “inside air”) that sucks air in a compartment that discharges bubbles is used (for example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 6-165837

  In the high expansion foam fire extinguishing equipment of inside air, the foaming ratio may not be as designed depending on the quantity and quality of smoke generated at the time of fire. For example, when the designed foaming ratio is 500, the actual foaming ratio is 100. When the expansion ratio is reduced in this manner, it is impossible to completely cover the fire source with the bubbles, so that the suffocation can not be effectively performed. The reason why the expansion ratio is lowered will be described in detail later, but it is mainly the presence of smoke in the air.

  In view of the above circumstances, an object of the present invention is to prevent a reduction in expansion ratio.

  The present invention is a high-expansion foam fire extinguishing equipment that sucks air in a discharge section into a flow path tube having a built-in radiation nozzle and causes the aqueous solution discharged from the radiation nozzle to collide with a foaming net to foam. The aqueous solution supply pipe of the radiation nozzle is provided with air or inert gas mixing means.

  The air or inert gas mixing means of the present invention comprises a gas cylinder filled with an inert gas, or an inlet connected to an aqueous solution supply pipe on the aqueous solution supply side, continuous to the inlet, and on the radiation nozzle side A divergent outlet connected to the aqueous solution supply pipe, an air supply part communicating with the vicinity of the inlet at the outlet, one end connected to the aqueous solution supply pipe on the aqueous solution supply side, and the other end connected to the air It is an air mixer provided with the bypass pipe which is arrange | positioned at the supply part and is provided with the nozzle at the other end.

  The present invention is a foaming method for a high expansion foam fire extinguishing equipment that sucks air in a discharge section into a flow path cylinder, discharges a foam aqueous solution from a radiation nozzle provided in the flow path cylinder, and collides with a foaming net. A gas-liquid mixed fluid obtained by mixing the aqueous solution and air or an inert gas is supplied to the radiation nozzle.

  The mixed fluid air or inert gas according to the present invention is characterized by being mixed almost uniformly into the aqueous solution.

  Since the present invention is configured as described above, the gas-liquid mixed fluid is supplied to the radiation nozzle. In this gas-liquid mixed fluid, air or inert gas is mixed with the foam aqueous solution, so the density of the aqueous solution supplied to the radiation nozzle is smaller than that of the aqueous solution, and the droplets of the emitted aqueous solution The number is also lighter.

  In addition, since the air of the gas-liquid mixed fluid is compressed, when it is radiated into the atmosphere, it expands and resists the droplets of the aqueous solution that travels toward the foaming net 7. The flow rate is slow. Accordingly, the droplets of the aqueous solution radiated from the radiating nozzle gently collide with the foaming net and foam in a sufficiently slowed state, and thus can be efficiently foamed.

  The present inventor researched and experimented on the cause of the decrease in the expansion ratio of the high expansion foam fire extinguishing equipment, and found that "smoke" had the main cause. This smoke is generated in the chamber (foam discharge section) due to the occurrence of a fire, but floats in the room as liquid fine particles, for example, fine particles having a particle diameter of 1 μm or less. When the fine particles are mixed with the air in the radiation section and sucked into the air suction part, they are supplied to the foaming part together with the air, and the foaming ratio is lowered.

  The present inventor has realized that it is only necessary to remove the smoke particles in order to solve the above problem, but it may be possible to prevent the reduction of the expansion ratio without removing it. Thought.

  Generally, a foam such as a highly expanded foam is a two-layer film of a surfactant contained in a foam stock solution, and is composed of an inner thin film and an outer thin film that sandwich a hydrophilic region. However, it is said that it will hold air and become a foam. The inventor of the present invention has a low foaming rate when foreign matters such as smoke particles are present. The formation rate of the two thin films is slow, and when the radiation nozzle is operated with a standard setting, the emitted bubbles are reduced. It was thought that this was because the droplet speed of the aqueous solution was so high that the two thin films could not be formed side by side and passed through the mesh.

  As a solution to the above problem, it is conceivable that the radiation pressure is made smaller than the standard setting to lower the ejection speed of the radiation nozzle so that the droplets of the foam aqueous solution slowly pass through the mesh. Therefore, when the foaming state of the foam aqueous solution having a predetermined concentration was changed by changing the spray pressure of the radiation nozzle, the foaming ratio was reduced to 1/5 or less compared to normal when the spray pressure was 0.5 MPa. And at 0.2Mpa, it decreased only to about 4/5.

  In this way, when the radiation pressure of the aqueous foam solution is reduced, foaming is facilitated, but the amount of air suction and the amount of aqueous radiation bubble solution are less than the standard settings. For this reason, the foaming amount is reduced, and a desired foaming amount cannot be obtained within a predetermined time.

  In order to solve the above problem, the present inventor has conducted an experimental study, and as a result, has found that air or inert gas mixing means may be provided in the aqueous solution supply pipe of the radiation nozzle. Using this mixing means, air or an inert gas is mixed with the aqueous solution to generate a gas-liquid mixed fluid, and the gas-liquid mixed fluid is supplied to the jet nozzle so as to collide with the foaming wire mesh of the aqueous solution. Has been found to be able to adjust appropriately. The present invention has been made based on the above findings.

An embodiment of the present invention will be described with reference to FIGS.
A room (chamber) 1 which is a foam discharge section is provided with a highly expanded foam fire extinguishing equipment. This fire extinguishing equipment is a foam foamer provided with the flow path cylinder 2, and the foaming ratio is set to 500, for example. The flow path cylinder 2 is provided with a foaming portion 3 that sucks air in the discharge section 1 to foam the aqueous solution.

  A foaming net (net) 7 is stretched on the foaming portion 3 at the tip of the flow path cylinder 2, and a plurality of radiations that are opposed to the foaming net 7 at an interval are disposed inside the foaming net 7. A nozzle 9 is provided. The radiation nozzle 9 is connected via an aqueous solution supply pipe 8 to an aqueous solution supply source (not shown) that generates a foam aqueous solution that is a mixture of the foam stock solution and water.

  The aqueous solution supply pipe 8 is provided with an air mixer 10. The air mixer 10 includes an inlet portion 12 connected to an aqueous solution supply pipe 8a on the aqueous solution supply source side, and a divergent outlet portion connected to the aqueous solution supply pipe 8b on the radiation nozzle 9 side that is continuous with the inlet portion 12. 14, an air supply part 16 communicating with the vicinity of the inlet part 12 in the outlet part 14, one end connected to the aqueous solution supply pipe 8 a, the other end disposed in the air supply part 16, and the other end And a bypass pipe 20 provided with an aqueous solution nozzle 18.

  The inlet portion 12 is formed in a cylindrical shape, and the diameter of the inlet portion 12 is larger than the diameter of the tip of the outlet portion 14, and the diameter of the rear end of the outlet portion 14 is the same as that of the inlet portion 12. Although formed in the same size as the diameter, these diameters are appropriately selected as necessary. In the air mixer 10, the aqueous solution nozzle 18 is provided to increase the suction force of the air k, but the nozzle 18 may be omitted because the divergent outlet portion 14 has a suction effect.

Next, the operation of this embodiment will be described.
When a fire occurs in the room 1, a fire detector (not shown) detects the fire and sends a fire signal to the control panel. Then, the control panel activates the high expansion foam fire extinguishing equipment, so that the room air, that is, the smoke in the room (discharge section) 1 in which the flow path cylinder 2 is disposed in the foaming portion 3 of the flow path cylinder. Air K containing H is aspirated.

Further, the foam aqueous solution w flowing in the aqueous solution supply pipe 8a flows into the aqueous solution supply pipe 8b through the inlet portion 12 and the outlet portion 14 of the air mixer 10, but is squeezed in the vicinity of the tip of the outlet portion 14. A negative pressure is generated in the vicinity of the tip. Therefore, the air k1 is sucked from the air supply unit 16, and the air k1 is mixed into the aqueous solution w, so that a gas-liquid mixed fluid wk is generated.
The gas-liquid mixed fluid wk is preferably in a state (preliminary foaming state) in which the air k is almost uniformly mixed with the aqueous solution w and is easily foamed.

A part w1 of the aqueous solution w flowing through the aqueous solution supply pipe 8a is diverted to the bypass pipe 20 and radiated from the aqueous solution nozzle 18 into the outlet portion 14. Therefore, the negative pressure in the outlet portion 14 is further increased, so that a sufficient amount of air can be reliably sucked as required. The air k1 of the gas-liquid mixed fluid wk is smaller than the aqueous solution w, for example, about 10% of the total volume of the fluid wk (pressure 5 kg / cm ² ). It is selected appropriately.

  When the gas-liquid mixed fluid wk is radiated from the radiation nozzle 9, the air k1 is opened to the atmosphere and expands, and becomes a resistance of the aqueous solution droplet wd traveling toward the foaming net 7. After the droplets wd are dispersed and the flow velocity is reduced, the droplets wd collide with the foaming net 7 and enter the mesh to be foamed (main foaming state). Therefore, the aqueous solution droplets wd can efficiently form the highly expanded foam 12.

A second embodiment of the present invention will be described with reference to FIG. 4. The same reference numerals as those in FIGS. 1 to 3 have the same names and functions.
The difference between this embodiment and the first embodiment is that a gas cylinder 25 is used as air or inert gas mixing means.

The gas cylinder 25 is filled with an inert gas such as nitrogen gas, oxygen dioxide gas, or argon gas at a predetermined pressure. In this embodiment, an inert gas g is mixed with the aqueous solution w while controlling the gas supply amount by a control valve (not shown) provided in the gas cylinder 25 to generate a gas-liquid mixed fluid wg.
When this gas-liquid mixed fluid wg is radiated from the radiation nozzle 9, the inert gas g is wrapped in the foam and covers the fire source together with the foam, so that the fire extinguishing efficiency can be improved.

It is a longitudinal cross-sectional view which shows 1st Example of this invention. It is an expanded sectional view of an air mixer. It is the sectional view on the AA line of FIG. It is a longitudinal cross-sectional view which shows 2nd Example of this invention, and is a figure corresponding to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Release section 2 Channel cylinder 3 Foam part 7 Foaming net 9 Radiation nozzle 10 Air mixer 12 High expansion foam 25 Gas cylinder

Claims (4)

A high-expansion foam fire extinguishing facility that sucks air in a discharge section into a flow path tube having a built-in radiation nozzle and causes the aqueous solution discharged from the radiation nozzle to collide with a foaming net to foam.
A high-expansion foam fire extinguishing system, characterized in that air or inert gas mixing means is provided in the aqueous solution supply pipe of the radiation nozzle. The air or inert gas mixing means comprises:
Gas cylinder filled with inert gas, or
An inlet connected to the aqueous solution supply pipe on the aqueous solution supply side, a divergent outlet connected to the aqueous solution supply pipe on the radiation nozzle side, and communicated with the vicinity of the inlet of the outlet An air mixer comprising: an air supply unit; and a bypass pipe having one end connected to the aqueous solution supply source, the other end disposed in the air supply unit, and the other end provided with a nozzle.
2. The high expansion foam fire extinguishing equipment according to claim 1, wherein A foaming method for a high expansion foam fire extinguishing equipment that sucks air in a discharge section into a flow path cylinder, discharges an aqueous solution from a radiation nozzle provided in the flow path cylinder and collides with a foaming net,
A foaming method for a high expansion foam fire extinguishing equipment, wherein a gas-liquid mixed fluid obtained by mixing the aqueous solution and air or inert gas is supplied to the radiation nozzle.   The foaming method for a high expansion foam fire extinguishing system according to claim 3, wherein the air or inert gas of the gas-liquid mixed fluid is mixed almost uniformly with the aqueous solution.

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