Can foam extinguishers be used to put out fires involving trichlorosilane?
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Our plant’s intermediate tank area contains 16 horizontal tanks of various sizes. The main materials stored there are trichlorosilane, silicon tetrachloride, silanes, etc. The foam used in this tank area is fluoroprotein medium-expansion foam, with a mixing ratio of water to concentrate of 97 to 3.
It is best to use sand; in case of a small amount of leakage, it can also be washed with water.
Using foam is not very suitable, as it has similarities to water. It is recommended to use dry powder.
No. Dry powder or sand can be used; in the case of minor leaks, a large amount of water can be used for flushing.
Chlorosilanes undergo hydrolysis when exposed to water, releasing hydrogen gas, and can explode when in contact with an open flame. In fact, as the scale of polysilicon production increases, the storage of trichlorosilane becomes increasingly important. However, no manufacturers have been able to find a solution to large-scale leaks of chlorosilanes. In the event of a major leak, which usually occurs in open areas, water mist can be sprayed around the storage tanks, and personnel should quickly evacuate to an area upwind, as hydrogen chloride gas is extremely harmful to the lungs.
Water-resistant foaming agents can be used to extinguish trichlorosilane fires, as when water is mixed with such agents to form foam, the foam contains very little water; moreover, this foam creates a carbonized layer that prevents water and air from reaching the material. The foam for firefighting is stored in foam tanks, while water is supplied by fire pumps. Since the liquid storage tanks are designed to deliver liquids in precise proportions, the foam produced contains very low levels of water. Fire safety regulations specify that when dealing with such polar chemical substances during firefighting, it is possible to use water-based film-forming agents in combination with dry powder to achieve better fire extinguishing results.
The answer is correct! There are many such examples abroad; I hope that the colleagues working in polysilicon factories will consider changing the fire protection design for storage tanks! :Lol, I must have misled you with 97\3! !
The design institutes design foam-based fire suppression systems; foreign polysilicon manufacturers use foam and water for fire suppression. Foam is generally used in areas where large quantities of chlorosilanes are stored, such as tanks.
The water in the foam reacts with chlorosilanes first, so using an aqueous foam for fire suppression may not be appropriate.
In the event of a chlorosilane leak, cover it with dry sand; after cleaning, wash the area with water. When a chlorosilane catches fire, there’s no good solution other than letting it burn out. All that can be done is to control the fire and prevent other equipment and people from being harmed, while taking necessary measures to minimize environmental pollution as much as possible.