Fire extinguisher
It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user (i.e., no escape route, smoke, explosion hazard, etc.
This device was probably used to a limited extent, as Bradley's Weekly Messenger for November 7, 1729, refers to its efficiency in stopping a fire in London.
A portable pressurised fire extinguisher, the 'Extincteur', was invented by British Captain George William Manby and demonstrated in 1816 to the 'Commissioners for the affairs of Barracks'; it consisted of a copper vessel of 3 gallons (13.6 liters) of pearl ash (potassium carbonate) solution contained within compressed air.
The soda-acid extinguisher was first patented in 1866 by Francois Carlier of France, which mixed a solution of water and sodium bicarbonate with tartaric acid, producing the propellant carbon dioxide (CO2) gas.
His extinguisher used the reaction between sodium bicarbonate solution and sulfuric acid to expel pressurized water onto a fire.
When the solutions were mixed, usually by inverting the unit, the two liquids reacted to create a frothy foam, and carbon dioxide gas.
Key features were a screw-down stopper that kept the liquids from mixing until it was manually opened, carrying straps, a longer hose, and a shut-off nozzle.
Fire department types were often private label versions of major brands, sold by apparatus manufacturers to match their vehicles.
In 1910, The Pyrene Manufacturing Company of Delaware filed a patent for using carbon tetrachloride (CTC, or CCl4) to extinguish fires.
[8] The liquid vaporized and extinguished the flames by inhibiting the chemical chain reaction of the combustion process (it was an early 20th-century presupposition that the fire suppression ability of carbon tetrachloride relied on oxygen removal).
Carbon tetrachloride extinguishers were withdrawn in the 1950s because of the chemical's toxicity – exposure to high concentrations damages the nervous system and internal organs.
It consisted of a tall metal cylinder containing 7.5 pounds (3.4 kg) of CO2 with a wheel valve and a woven brass, cotton-covered hose, with a composite funnel-like horn as a nozzle.
[12] CO2 is still popular today as it is an ozone-friendly clean agent and is used heavily in film and television production to extinguish burning stuntmen.
An anecdotal report of a carbon dioxide fire extinguisher was published in Scientific American in 1887 which describes the case of a basement fire at a Louisville, Kentucky pharmacy which melted a lead pipe charge with CO2 (called carbonic acid gas at the time) intended for a soda fountain which immediately extinguished the flames thus saving the building.
This was the first agent available for large-scale three-dimensional liquid and pressurized gas fires, but remained largely a specialty type until the 1950s, when small dry chemical units were marketed for home use.
ABC dry chemical came over from Europe in the 1950s, with Super-K being invented in the early 1960s and Purple-K being developed by the United States Navy in the late 1960s.
The revised NFPA 10 created criteria on the placement of "fast flow extinguishers" in locations such as those storing and transporting pressurized flammable liquids and pressurized flammable gas or areas with possibility of three-dimensional class B hazards are required to have "fast flow extinguishers" as required by NFPA 5.5.1.1.
[24] NZ Transport Agency recommends[25] that all company vehicles carry a fire extinguisher, including passenger cars.
They are referred to as clean agents because they do not leave any residue after discharge, which is ideal for protecting sensitive electronics, aircraft, armored vehicles and archival storage, museums, and valuable documents.
Most class D extinguishers will have a special low-velocity nozzle or discharge wand to gently apply the agent in large volumes to avoid disrupting any finely divided burning materials.
The modern version of the ball is a hard foam shell, wrapped in fuses that lead to a small black powder charge within.
The ball bursts shortly after contact with flame, dispersing a cloud of ABC dry chemical powder which extinguishes the fire.
From about 1880 glass "fire grenades" filled with a weak solution of common salt and ammonium chloride in water were popular.
To the difference of gaseous suppressants, which emit only gas, and dry chemical extinguishers, which release powder-like particles of a large size (25–150 μm) condensed aerosols are defined by the National Fire Protection Association as releasing finely divided solid particles (generally <10 μm), usually in addition to gas.
[46] Whereas dry chemical systems must be directly aimed at the flame, condensed aerosols are flooding agents and therefore effective regardless of the location and height of the fire.
Additionally, wet chemicals (such as potassium carbonate) are dissolved in water, whereas the agents used in condensed aerosols are microscopic solids.
In 2015, researchers from George Mason University announced that high volume sound with low bass frequencies in the 30 to 60 hertz range drives oxygen away from the combustion surface, extinguishing the fire, a principle was previously tested by the Defense Advanced Research Projects Agency (DARPA).
Recently the NFPA and ICC voted to allow for the elimination of the 30-day inspection requirement so long as the fire extinguisher is monitored electronically.
According to NFPA, the system must provide record keeping in the form of an electronic event log at the control panel.
The system must also constantly monitor an extinguisher's physical presence, internal pressure and whether an obstruction exists that could prevent ready access.
