How does co2 extinguisher work

Class C fires, which involve energized electrical equipment, can also be extinguished with CO2. CO2 displaces the oxygen to extinguish the fire. When the CO2 gas is released from the extinguisher it looks like dry ice. This type of extinguisher does not work well outside due to wind drift.

The wind can blow the carbon dioxide off of the fire and bring oxygen back to the flames. The discharge range is fairly small. Once CO2 is released from the extinguisher, it will start to spread, as gases do. Because of this, the horizontal discharge range of the CO2 stream is limited to feet. This range is about half the average range for an ABC extinguisher. It is propelled at high speed as a cold white jet onto the flame. The CO2 works to smother the fire, greatly reducing the oxygen from the source.

The cold nature of the matter brings down the temperature of the fire, eliminating the heat element. The potential downfall of these extinguishers is that the displacement of oxygen from a fire may not be permanent enough to stop the flame re-igniting.

This is why they are only suitable for smaller contained flames. The fire extinguisher is chock full of carbon dioxide in liquid form, pressurized of course but when the extinguisher is used the CO2 expands in the atmosphere and turns into gas. The CO2 gas is heavier than the oxygen in the air so it effectively pushes it out, displacing it from around the fuel which is burning to cause the fire.

The fire is extinguished because the oxygen it needs to feed the flames has been replaced by the carbon dioxide gas. This is the very basic method in which a carbon dioxide extinguisher can fight fires. This type of extinguisher is particularly popular in restaurants because the carbon dioxide quickly disperses without spoiling the food or the cooking equipment. Direct the CO2 at the base of the fire and move it gradually along the entire area of the flames.

Carbon dioxide extinguishes work by displacing oxygen, or taking away the oxygen element of the fire triangle. The carbon dioxide is also very cold as it comes out of the extinguisher, so it cools the fuel as well. CO2s may be ineffective at extinguishing Class A fires because they may not be able to displace enough oxygen to successfully put the fire out.