JPH0728936B2 - Fire extinguisher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a fire extinguisher, particularly a fire extinguisher capable of effectively and easily extinguishing a vegetable oil such as tempura oil or frying oil. is there.

[Prior Art] In vegetable oils used for tempura, fries, etc., both the ignition temperature and the ignition temperature of the oil are 300 ° C or higher, and in the case of a fire, the oil temperature is at most 410 ° C.

Conventionally, some fire extinguishing agents such as powder have been proposed for such a fire, and some of them have been commercialized.

[Problems to be Solved by the Invention] However, these powder fire extinguishing agents have a drawback of re-ignition because they are poor in the effect of lowering the oil temperature below the ignition temperature even when the fire is extinguished.

[Means for Solving Problems] The present inventor has conducted various studies and studies for the purpose of eliminating such drawbacks, finding a fire extinguishing agent which can effectively and reliably and quickly extinguish a fire of vegetable oil, and which is easy to handle. As a result, they have found that the above object can be achieved by using silicon dioxide having specific physical properties and carbonate or bicarbonate. Thus, the present invention provides 20-60% after aging the silica sol.
Silicon dioxide obtained by drying at a temperature of ℃, having an average particle size of 10 to 20 μm in an aggregated state and a water content of 80 to 20% by weight.
Of silicon dioxide and carbonate and / or bicarbonate as main components, and the amount of carbonate and / or bicarbonate used is 5 to 25 relative to the total amount of silicon dioxide and carbonate and / or bicarbonate. % To provide a fire extinguishing agent.

The silicon dioxide used in the present invention has a water content of
It is necessary to have 80 to 20% by weight, and as a means for embodying this, one containing silanol groups in silicon dioxide is used.

Such silanol groups are such that when silicon dioxide is heated to 100 ° C., 90% or more of the silanol groups are rapidly decomposed and evaporated as water. The silicon dioxide of the present invention is obtained by aging a silica sol and then drying it at a temperature of 20 to 60 ° C. For example, a silica sol having a desired particle size is formed by a commonly used reaction between sodium silicate and sulfuric acid, and this is aged by an ordinary means.However, in the next drying step, a low temperature such as 20 to 60 ° C is adopted. It can be obtained by drying for a long time. As an example of the drying process, first, the product is kept at 60 ° C. for 5 hours, then at 40 ° C. for 7 hours, then at 35 ° C. for 6 hours and then gradually cooled to obtain silicon dioxide having a water content of 55% by weight. Can be done.

By selecting the drying temperature and time in this way, silicon dioxide having a desired water content can be obtained.

Of these water contents, the use of 80 to 35% by weight is particularly preferable because the fire can be extinguished effectively and stably.

Further, it is appropriate that the average particle diameter of silicon dioxide used as a fire extinguishing agent is about 10 to 20 μm in the agglomerated state.

Furthermore, these silicon dioxides have a specific surface area of 200-200 by the BET method.
1200m ² / g, pore diameter 10-300Å, pore volume 0.4-2.5ml /
It is preferably g, and by having such physical properties, it becomes possible to utilize the water in the silicon dioxide rapidly and sufficiently effectively for extinguishing the fire.

Further, in the present invention, a carbonate or a bicarbonate is used together with these silicon dioxides. Sodium carbonate and potassium carbonate may be used as the carbonate, and sodium bicarbonate and potassium bicarbonate may be used as the bicarbonate as appropriate, alone or in combination. The amount of these used is appropriately 5 to 25% by weight based on the total amount of the silicon dioxide. Carbonates and bicarbonates have a function of forming a saponification film on the surface of oil and have a great effect of blocking air. If the amount used is less than 5% by weight, it is difficult to expect a sufficient air blocking effect, and conversely 25% by weight.
If it exceeds, the cooling effect of silicon dioxide is substantially impaired, so that it is not suitable.

Thus, when such an extinguishing agent is actually used, for example, it is stored in a bag or the like, and when a fire occurs in the tempura pan, it is put therein. The injection method does not necessarily have to cover the fire surface, and the injection amount may be about 20% of the oil amount.

By doing so, the silanol groups contained in the input silicon dioxide are decomposed by the heat of the oil, and the heat of the oil is taken when the water evaporates, and the oil temperature can be effectively lowered from the ignition point. At the same time, it becomes possible to effectively block the air by forming a saponification film by the carbonate or bicarbonate.

The fire extinguishing agent according to the present invention has a very effective fire extinguishing action against oil fires such as oil for tempura and oil for frying, that is, vegetable oil, in other words, an ignition temperature of around 300 to 400 ° C. In addition, there is an advantage that flame does not rise at the time of use, it does not solidify or deteriorate, it is inexpensive and has no toxicity, and it can be widely spread in households.

[Example] Example 1 1100 g of tempura oil was put into an iron pan, and the pan was heated to an oil temperature of 340 ° C.
It ignited at. At this time, it has 33% by weight of SiO _2, 67% by weight of silanol groups converted to water (97% of this is rapidly decomposed into water at 100 ° C), and has a specific surface area of 800
~ 1000m ² / g, pore size 80-150Å, pore volume 2ml / g, average particle size 14μm of silicon dioxide (PQ Co., Ltd., product name Brightsolve) 100g and sodium carbonate powder 20g The heat source was removed by spraying on top.

The temperature of the oil in the pan dropped sharply to 320 ° C after the chemical was added, and after 12 seconds, it extinguished completely and the oil temperature was 310 ° C.
It has reached ℃. During this time, there was no danger of rising flames or splashing oil.

Example 2 A pan similar to that in Example 1 was ignited and continued to be burned for 1 minute.
The temperature rose to 355 ° C and the flame rose 1 m. At this time, it has 67% by weight of SiO ₂ , 33% by weight of water-converted silanol groups (94% of which rapidly decomposes into water at 100 ° C) and has a specific surface area of 1000 to 1200 m ² / g. , A commercially available silicon dioxide 200 with an average particle size of 17 μm having a pore size of 30 to 40 Å and a pore volume of 0.6 ml / g.
The mixture was sprayed with a mixture of g and 25 g of sodium bicarbonate powder, and the heat source was removed.

The extinguishing effect was almost the same when a mixture of 15 g of sodium bicarbonate powder and 10 g of sodium carbonate powder was used instead of the sodium bicarbonate powder.

Claims (6)

[Claims] 1. A silicon dioxide obtained by aging a silica sol and then drying at a temperature of 20 to 60 ° C., which has an average particle size of 10 to 20 μm in an agglomerated state and a water content of 80 to 20% by weight. And carbonate and / or bicarbonate as main components, and the amount of carbonate and / or bicarbonate used is 5 to 25% by weight with respect to the total amount of silicon dioxide and carbonate and / or bicarbonate. A fire extinguisher. 2. The fire extinguisher according to claim 1, wherein the silicon dioxide contains a silanol group. 3. Silicon dioxide has a specific surface area of 200 to 1200 m ² / g,
The fire extinguisher according to claim (1) or (2), having a pore size of 10 to 300Å and a pore volume of 0.4 to 2.5 ml / g. 4. The fire extinguisher according to any one of claims (1) to (3), wherein the carbonate is sodium carbonate or potassium carbonate. 5. The fire extinguisher according to any one of claims 1 to 4, wherein the bicarbonate is sodium bicarbonate or potassium bicarbonate. 6. The fire extinguisher according to any one of claims (1) to (5), wherein the fire extinguisher is for a vegetable oil fire.