Fire Extinguishers
A fire extinguisher is a device to put out fires, often in an emergency situation. They consist of a pressurized container of chemicals that when discharged can put out a fire. more...
It is important to familiarise yourself with the use of fire extinguishers in your vicinity, as improper or untimely use may be counterproductive.
History
The first version of the modern fire extinguisher was invented in the United Kingdom by Captain George Manby in 1816, consisting of a copper vessel of 3 gallons (13.6 litres) of pearl ash (potassium carbonate) solution under compressed air pressure.
The late 19th century saw the invention of the Soda-Acid extinguisher where a cylinder contained 1 or 2 gallons of water that had sodium bicarbonate mixed in it. Suspended in the cylinder was a phial containing concentrated sulfuric acid. Activating the extinguisher by striking a plunger to break the phial, or inverting the extinguisher to release a lead bung from the phial (depending on type), released the acid which mixed with the bicarbonate solution to generate carbon dioxide gas that expelled the water under pressure through a nozzle or short length of hose.
Around 1912 Pyrene pioneered the carbon tetrachloride or CTC extinguisher, where the liquid was expelled from a brass or chrome container by handpump, usually of 1 imperial quart (1.1 L) or 1 imperial pint (0.6 L) capacity but also made in up to 2 imperial gallon (9 L) size, onto a fire. The CTC vapourised and extinguished the flames by chemical reaction. This extinguisher was suitable for liquid and electrical fires and was popular in motor vehicles for the next 60 years. The vapour and combustion by-products were highly toxic and deaths did occur from using these extinguishers in confined spaces.
Construction
General
A fire extinguisher is usually made using the following components :
Read more at Wikipedia.org