Fire Extingishers

Fire Extinguishers In 200 BC, the romans used bucket brigades or bucket chains to put out fire until Ctesibius of Alexandria invented the hand pump to deliver fire to the water. In the Middle Ages ‘squirts’ began to apply jets of water to fires. It wasn’t until after the Great Fire of London that a more modern fire extinguisher was created. The first version of the modern portable fire extinguisher was invented by Captain William Manby in 1819, consisting of a copper vessel of three gallons of pearl ash solution under compressed air pressure. The extinguisher was used in liquid and electrical fires and was popular in automobiles for about 60 years. Although the extinguisher did put out the fire, the vapor and combustion by-products were highly toxic and deaths did occur from using these extinguishers in confined spaces. It wasn’t until the 19th century that soda-acid extinguishers were created. It was a cylinder that contained one or two gallons of water that had sodium bicarbonate mixed in it. Foam extinguishers were introduced in the middle of the twentieth century. The foam extinguishers consisted of the main body of the extinguisher filled with foam producing chemical and a second container filled with another chemical which reacts when it came into contact with the solution in the main cylinder. There are two main types of fire extinguisher. The first types are pressurized with air approximately 10 bar, five times a car tire pressure, from a compressor. A squeeze grip handle conducts a spring loaded valve attached to the pressure cylinder which makes the pipe or dip tube inside extend to the bottom of the extinguisher so that in the upright position the opening of the tube is plunged. The agent is than released through a hose and nozzle pushed out by the pressure above it. The second type of fire extinguishers are the gas cartridge types which are made the same way but the pressure source is carbon dioxide rather than air. This extinguisher was