Extinguishing principle of foam extinguisher
In addition to the two reactants, a number of blowing agents were added to the fire extinguisher. Open the switch; the foam is ejected from the fire extinguisher, covering the burning material, isolating the burning substance from the air, and lowering the temperature to achieve the purpose of extinguishing the fire. As the foam from the foam extinguisher contains a lot of water, it is not as good as carbon dioxide liquid fire extinguisher. It does not pollute the material after fire and leaves no trace.
There are two containers in the foam extinguisher, which contain two kinds of liquids respectively. They are aluminium sulfate and sodium bicarbonate solution. The two solutions do not contact each other, and no chemical reaction occurs. When you need a foam extinguisher, put the extinguisher upside down and mix the two solutions together, which will produce a large amount of carbon dioxide gas:Al2 (SO4) 3+6NaHCO3==3Na2SO4+2Al (OH): +6CO2 = 3
Al2 (SO4) 3+6NaHCO3==3Na2SO4+2Al (OH): +6CO2 = 3 according to carbon dioxide can not burn, nor support the combustion of nature, people developed a variety of carbon dioxide extinguishers, a foam fire extinguisher, fire extinguisher and fire extinguisher liquid carbon dioxide. The principle and operation method of foam extinguisher are briefly described below.
