How they work
The patented solid aerosol generating compound (extinguishing media A) is contained within a steel canister inside the extinguisher.
Pressing the start button initiates a controlled combustion process which converts the solid into an aerosol suspending nano-particle extinguishing agent (extinguishing media B).
The energy created during the controlled burn propels the aerosol and the particles that are suspended in the aerosol are 0.01 microns in size (that's about 600 times smaller than the width of a hair).
As a safety feature of Fire One extinguishers; the generated extinguishing agent passes through a cooling chamber prior to exiting the discharge nozzle. This process ensures a discharge temperature less than 35 degrees celcius to prevent burns to the user.
How Fire One products put out fires
All fires require heat, fuel, oxygen and a chemical chain reaction to continue to burn. Removing any one of these four elements will cause a fire to go out.
When heat is applied to a combustible material it will begin to breakdown which releases flammable vapour (this is the fuel and actually what ignites).
Oxygen is also required for combustion (fire), which essentially increases the rate of material breakdown - its rapid oxidisation! So now we have heat, fuel and oxygen; this is the fire triangle.
The process is self perpetuating and is also a change in the chemical structure of the elements at the point of combustion. The chemical elements are being broken apart and become a new different chemical structure - its a chain reaction of one thing becoming another.
Part of the chain reaction of combustion the elements of hydroxide, hydrogen and oxygen are released, these elements become accessible to sustain combustion and if they are removed combustion will cease.
A crude way to visualise this is like a row of dominos falling, one knocks the next down in a chain reaction, but if you remove a few it will interrupt the dominoes falling, the chain reaction is interrupted and the dominos stop falling.
Fire One condensed aerosol extinguishers and Suppression Stickers use interrupting the chemical chain reaction as their primary method of extinguishment.
Specifically the particles they expel bind to the hydroxide, hydrogen and oxygen which then form a new chemical element meaning they are no longer available to sustain the combustion. The dominos so to speak have been removed.
Need to know more..
Read below for more detail about hot (condensed) aerosol extinguishing agents mechanisms of extinguishment:
Cooling effect of endothermic decomposition
The cooling effect of hot aerosol fire extinguishing agents is achieved by endothermic decomposition of metal oxides and carbonates.
Solid particles in the aerosol absorb part of the heat emitted by the fire reducing the temperature of the flame. Through heat absorption, less radiated heat is directed back to the combustible object. Less radiated heat reduces gasified combustible molecules that will be broken into free radicals thus impacting on the combustion process.
Chemical inhibition (Gas phase)
Under the action of heat, hot aerosol fire extinguishing agent metal ions such as Sr, K, or Mg are vaporized / decomposed in to steam occurring more frequently with the active groups H •, • OH, and O • of combustion.
Secondary chain reaction, the following takes Sr as an example:
Sr+2•OH→Sr（OH）2 Sr+O•→SrO Sr（OH）2+2H•→Sr+2H2O
Repeatedly, the active groups in the combustion are consumed in large quantities, the concentration is continuously reduced, and the combustion is suppressed.
Chemical inhibition (Solid phase)
The solid particles in the hot aerosol fire extinguishing agent can adsorb the chain reaction intermediates oh, h, and o, and catalyze them to reconstitute stable molecules, thereby interrupting the branched chain reaction of the combustion process.
In the above fire extinguishing effect, several fire extinguishing mechanisms interact and play synergistically, but the gas transmission effect and the endothermic and cooling effect only serve as auxiliary actions. The main fire extinguishing effect still relies on gas chemical inhibition in the solid phase.