JPS60122576A - Powdery fire extinguishing agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry powder fire extinguisher suitable for extinguishing liquid combustible materials such as oils and solvents, particularly for extinguishing liquid combustible materials in the initial stages.

Conventionally, various powder extinguishing agents have been used for extinguishing fires caused by combustible substances such as oil, especially for initial extinguishing, but few of these powder extinguishing agents are necessarily effective for initial extinguishing.

The main material of the present invention is fine powder silica, which has the ability to retain a predetermined amount of moisture and maintain a fine powder state with good fluidity. The object of the present invention is to provide a product that can diffuse and cover the ignited oil surface, rapidly lower the oil temperature, quickly extinguish the fire, and prevent future re-ignition of the oil surface.

As a result of various studies on chemically produced silica powder, the inventor found that, for example, fine powder silica produced by a dry method (hereinafter simply referred to as special silica) retains a large amount of water and has extremely fluidity. The present invention was achieved based on the discovery that it has the ability to maintain a fine powder form. That is, even when the above-mentioned special silica retains a moisture content of approximately 0% (by weight, hereinafter the same), it maintains a dry fine powder state with no moisture in appearance and has good powder fluidity. For example, the above-mentioned hydrated special silica with or without a certain amount of sodium bicarbonate powder is placed in a polyethylene film pouch, and the bag is heated and ignited in a container such as a pot with oil at a temperature of about 30θ°C.
When added to a certain amount of oil surface, the moisture-retaining special silica quickly disperses over the oil surface, uniformly covering the surface, blocking air and other substances, and at the same time, the moisture contained vaporizes and the surface temperature increases. fire can be easily extinguished immediately. As mentioned above, the water-containing special silica is dispersed and suspended in a thin layer on the oil surface and does not sink into the oil, so the water content vaporizes explosively in the high-temperature oil, creating a pillar of flame or scattering the high-temperature oil outside the vessel. There is no danger of this happening, even if the water content is about 2! Even if it sinks into the oil due to the temperature of θ to 3θO, it will easily disperse, so there will be very little chance of a pillar of fire or oil scattering.

The above-mentioned special silica is obtained by hydrolyzing silicon tetrachloride at about 1000°C in an oxyhydrogen flame, and has an average particle size of 1.
0-λθ millimicrons, bulk specific gravity approximately 0~t o t/
The particles mainly have silanol groups (
For example, one commercially available under the trade name of "Aerosil" (Nihon Aerosil Tadashi) could be suitably used.

Moisture-retaining special silica can exhibit fire extinguishing ability even when used alone, but in addition to the above-mentioned sodium bicarbonate, bicarbonates such as ammonium bicarbonate and potassium bicarbonate, and other known fire extinguishing gas-generating powder materials can also be used. The fire extinguishing ability can be further increased by adding a predetermined amount of

Particularly preferred in this case. It is also advisable to treat these powdered materials with a hydrophobizing agent to prevent them from absorbing moisture during long-term storage and deteriorating the fluidity of the powdered extinguishing agent.

As the hydrophobizing agent, silicone and various other materials can be used. For example, a powder material made hydrophobized using resilica "Aerosil R972J (trade name)" which is chemically covered with surface CHi groups and made hydrophobized is suitable. Yes 0 The amount of moisture retained in the special silica and the amount of the extinguishing powder material can be mixed in various ways depending on the amount of extinguishing agent applied to the surface of the ignited oil, but excellent extinguishing effects can be achieved with a relatively small amount. Regarding the formulation, according to the results of various fire extinguishing tests, for 700 parts of special silica (the same applies below weight), the retained moisture is SO to 3θθ parts, preferably 700 to 200 parts, and the fire extinguishing powder material is preferably 100 to .2θθ parts. is 10θ~
/Evening θ part. Even if the above-mentioned retained water content is less than about 50 parts, there is sufficient fire extinguishing ability, but the quick effect is lacking. Moreover, if it exceeds about 30 θ parts, the specific gravity of the powder increases and the dispersibility deteriorates. Also, if the amount of fire extinguishing powder material is less than 100 parts, the fire extinguishing ability will decrease,
0 parts or more is economically unfavorable.

In contrast to the above-mentioned special silica, porous inorganic powders such as wet-processable powder silica and pearlite have been tested to show that they are inferior in water retention capacity, and when the required amount of water, for example, son to /θ0, is added and hydrated. The powder state and fluidity before water absorption are not maintained, and even if a predetermined amount of dry powder of sodium bicarbonate is added to it, it does not become a powder state with good fluidity. When these extinguishing agents are poured onto the surface of high-temperature oil that has been heated to about 300°C and ignited, they are uniformly dispersed and suspended on the oil surface like the extinguishing agent of the present invention, without forming any coating layer. immediately sinks into the oil, the moisture in the oil evaporates explosively, and the bicarbonate decomposes, resulting in a column of fire from the generated gas and the hot oil scattering outside the container. The fluidity of a compound is the property that when a certain amount of a compound is placed in a beaker, the surface is made almost flat, and the beaker is tilted (maximum tilt angle of 900), the compound crumbles from the surface. This refers to the state in which the powder crumbles in a flowing state.

As special silica, [Aerosil 200J (trade name), water added to the silica and [Aerosil R972]C
The proportions of the above-mentioned raw materials and the external properties of the fire extinguishers, which were formulated with various proportions of bicarbonate powder such as sodium bicarbonate hydrophobized by the addition of (trade name)/H, were as shown in the description.

For comparison, [Fujigel B] was used instead of Aerosil 200.
J (engraving of wet process specification (no change in content), trade name of silica) and commercially available pearlite were used, and the blending ratio of the same raw materials as above and the external properties were also listed.

Raw material blending ratio and appearance properties, and a certain amount (2?, 3t, sr) of fire extinguishing agent of various compositions obtained by blending in the same manner as above, was folded into a container with a diameter of about 7 crn and a length of about 10 cr.
cm polyethylene film (thickness approx. 0.0611I+
1) Place it in a plastic bag, make it flat and seal it. (A) Approximately 300 ml of oil and fat (edible) in a container with a diameter of approximately / Ocm x a height of approximately 9 cm. , and (B), put about θ0v of similar oil into a frying pan with a diameter of about 20,
This is heated from the bottom with a burner, and the fat and oil smokes and ignites, and a blue flame begins to run across the oil surface.This changes to a red flame, and the oil surface is engulfed in flames and starts to burn (oil temperature approximately 30θ℃).
(above), when the seven powder fire extinguishing agent-filled bags were thrown onto the oil surface so as to be almost flat, the extinguishing situation, the conditions of the materials thrown in, the oil surface, etc. are as shown in the following table.

For comparison, "Fujigel B" and pearlite were used instead of "Aerosil 2θO", and the results of the same fire extinguishing test as described above are also shown.

Engraving of the statement (no changes to the contents) Engraving of the statement (no changes to the contents) Code listed in "Extinguishing status when extinguishing agent is added" in the table above The O mark extinguishes the fire instantly.

■ The fire extinguishes in j-10 seconds after injection.

X marks do not extinguish the fire.

This is what is shown.

As is clear from the results of the above fire extinguishing test, the powder fire extinguisher of the present invention has a low bulk specific gravity, and when it is poured onto the surface of ignited oil, it immediately diffuses and floats to cover the entire surface of the oil, and the large amount of water it contains evaporates, causing the entire surface of the oil to be completely covered. In addition to lowering the surface oil temperature, the entire surface is coated with floating silica and the CO2 gas generated by bicarbonate decomposition blocks air and enables immediate fire extinguishment. C0
There is no risk of re-ignition due to the coating with two gases. Even if the amount of water retained increases and the bulk specific gravity becomes large, and some of the extinguishing agent sinks when poured onto the oil surface, a pillar of flame will form on the oil surface as in the case of Fujigel B, Perlite, etc., or high-temperature oils and fats will There is no risk of it scattering outside the container.

The above fire extinguishing agent of the present invention can be produced, for example, by the following method. A certain amount of special silica in the form of ultrafine powder is placed in a mixer such as a ribbon mixer, and while the machine is running, the required amount of water that has been made into a fine mist is mixed with the silica in a manner that does not damage the ultrafine state of the silica. Gradually add it over the entire surface depending on the mixing condition, and after adding the specified amount, operate for a certain period of time to adjust the moisture content of each fine silica powder, and discharge the water-containing silica through a sieve. If there are any granules that do not pass through, crush them on a sieve or use a pulperizer to crush them. When bicarbonate such as dry finely powdered sodium bicarbonate is hydrophobized and mixed, a certain amount of dry powdered sodium bicarbonate or the like is placed in a suitable mixer, for example, a ribbon mixer similar to the one described above, and the mixer is operated. About 1/2 of the weight of the above-mentioned sodium bicarbonate, etc., of the hydrophobizing agent, such as [Aerosil R-72] (trade name), is divided into approximately equal parts, and % of the powder is gradually added intermittently into the mixer. After adding the entire amount, the mixer is further operated for a certain period of time to obtain a powder of sodium bicarbonate or the like in which the hydrophobizing agent is uniformly mixed. Next, the above-mentioned water-containing fine powder of special silica and hydrophobized sodium bicarbonate powder are charged into a mixer, for example, the above-mentioned ribbon mixer.
The mixer is operated for a certain period of time to obtain the required powder fire extinguishing agent that is uniformly mixed. This powder extinguishing agent is, for example, 20 tons,
A small unit amount of 309...1009, etc. is sealed flat in a bag made of polyethylene, easily meltable plastic, or other similar film, and the 7 or more lined portions are used in home kitchens,
If provided in the kitchen of a cafeteria or restaurant, when tempura oil or the like ignites, it can be thrown in to quickly and extremely easily extinguish the fire, thereby preventing fires from occurring.

In this case, the extinguishing agent is, for example, the charged powder extinguishing agent (1
) (Fig. 1) with a cut line (4) that can be easily cut out by hand, and 3 to j or more of them are fixed (
(Fig. 2), or the charged dry powder extinguishing agent (1
) fixed to the tip of a rectangular stiff mount board (5) (Fig. 3) and hang 3 to j or more of them in a place where there is a risk of fire, such as a kitchen or cooking area. If tempura oil etc. ignites, cut out 7 or more extinguishing agent bags from the mount board in the case of the former, or remove 7 or more of the extinguishing agent bags from the mount board in the case of the latter, while keeping them attached to the mount board. It can be used for immediate extinguishing of fire by grasping the end and throwing it onto the surface of the ignited oil.

(2) is a powder fire extinguisher, and (8) is a polyethylene film bag. Father, instead of bags, the dry powder extinguishing agent is stored in cylindrical, square box, or other containers containing 10 oz, toor, /Kf...
Fill the appropriate amount of oils, fats and other oils, etc.
It can be used to extinguish a fire by spraying it on the surface of a solvent or the like when it ignites, or by filling it in a conventional dry powder fire extinguisher or the like and spraying it onto the surface of an oil or other substance when it ignites.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 7 is a partially cutaway slope view, and FIGS. 2 and 3 are slope views showing modified examples, respectively. Procedural amendment is a formula) Showa! March 1999 Commissioner of the Japan Patent Office Kazuo Chikubo 1 Case Display Showa! ! Patent Application No. 2372♂3 2
Title of the invention Dry extinguishing agent 3 Relationship with the case of the person making the amendment Patent applicant 4 Attorney 7 Contents of the amendment “Extinguishing agent and its manufacturing method” is corrected to “/Name of the invention Dry extinguishing agent”. (2) Page 7 of the specification shall be amended as shown in the attached sheet. (No change in content) (3) Page 9 of the specification is amended as shown in the attached sheet. (No change in content) (4) Page 10 of the specification is amended as shown in the attached sheet. (No change in content) That's all

Claims (1)

[Claims] 7. A powder extinguishing agent containing as a main material finely powdered silica, which has the ability to retain a predetermined amount of moisture and maintain a fine powder state with good fluidity. 2 A predetermined amount of water is retained in finely powdered silica that retains a predetermined amount of water and maintains a fine powder state with good fluidity, and a fire-extinguishing gas-generating powder material is added to this water-retaining fine powder silica as the main material. Mixed powder extinguishing agent. 3. The powder fire extinguisher according to claim 1 or 2, wherein the finely powdered silica has a silanol group. The powder extinguishing agent according to claim 2, wherein the extinguishing gas-generating powder material is sodium bicarbonate. j. The powder fire extinguisher according to claim 2 or 7, wherein the fire extinguishing powder material is hydrophobized.