Introduction to Fire Protection and Emergency Services
When you wake up, you are met with a powerful odor of burnt wood and your eyesight is impaired, making it unclear whether you are in a dream or living through a horrifying nightmare. As you quickly get out of bed, the unusually warm floor beneath your bare feet verifies the terrifying truth – your house is on fire. Fueled by anxiety and adrenaline, every action is propelled as you dash towards the door and grab hold of the handle, which shocks you with its icy feeling. In your panicked state, you forcefully open the door, prepared to face the catastrophic scenario.
Upon noticing the open door, you immediately spot an object firmly attached to the wall. Although this is typically something that goes unnoticed, today it fills you with a sense of hope. Without hesitation, you approach the wall and detach the object before swiftly descending downstairs to confront the impending disaster. Upon reaching the landing and turning around the corner, you are faced with the source of all the smoke and intense heat: The curtains above a power outlet have caught fire. An abundance of extension cords and power strips are fueling the flames. Armed with the device in your hands, you diligently follow its straightforward instructions, directing its hose and activating its function by pulling on its trigger.
After a short time, the fire is put out and your house is no longer in danger of being destroyed by fire. As you calm down and feel relieved that there’s no more smoke around, your attention shifts to the device that might have saved your life – the fire extinguisher. This everyday object can be found in almost every American home, but how well do we know its features and capabilities? This article will explore the purpose and usage of the household fire extinguisher, with a special focus on the CO2 fire extinguisher.
The misconception that fire extinguishers are a modern invention is false. In fact, the initial fire extinguisher was created in England during the early 18th century by Ambrose Godfrey, a chemist. Godfrey’s innovation comprised of a pewter chamber that stored a liquid for extinguishing fires, alongside a smaller chamber that held gunpowder and fuses. Upon pulling the trigger, the fuses would ignite the gunpowder, leading to the release of the chemical agent from the device.
During the 1700’s in London, there was a one-time use extinguisher that proved effective against multiple fires. The fire extinguisher underwent several alterations and modifications over time. In 1866, Francis Collier of France invented a notable version called the soda-acid extinguisher. This type of extinguisher consisted of a canister filled with water and sodium bicarbonate. Suspended within this mixture was a capsule containing sulfuric acid. To use the extinguisher, the user would rupture the capsule using either a plunger or a pull-cord and then direct the hose towards the base of the fire.
When the bicarbonate solution and sulfuric acid were combined, a reaction would occur, generating abundant carbon dioxide. This reaction would lead to a substantial rise in pressure within the canister. Subsequently, the solution would be expelled through the hose onto the fire. Although not directly utilizing carbon dioxide to smother fires, the soda-acid extinguisher incorporated CO2 as an element, making it a precursor to modern CO2 fire extinguishers. As construction techniques advanced over time, there arose a demand for different kinds of fire extinguishers.
In 1904, Aleksandr Loran created the first chemical foam extinguisher to address the increasing problem of electrical fires in residential areas. This foam extinguisher provided an effective solution by using a conductible liquid agent to extinguish fires without endangering the user. In 1924, Walter Kidde invented the carbon dioxide fire extinguisher that is still widely used today. This innovation was a response to Bell Telephones Company’s request for a non-conductive chemical extinguisher to combat persistent fires in telephone switchboards.
The original version of the device featured a 7.5lb canister with a top-mounted wheel valve and a cloth insulated hose to direct the discharged gas. This extinguisher quickly gained popularity and became widely used in various businesses, including the telephone company. Notably, the movie industry adopted the CO2 extinguisher to safely extinguish stunt actors without exposing them to potentially toxic substances or leaving messy residue.
Over time, the wheel valve technology used in fire extinguishers was substituted with a hand trigger device commonly seen today. Likewise, the cloth-covered hose was exchanged for a rubber insulated hose. Some variations of fire extinguishers even include a cone-like nozzle at the end of the hose to generate a more conical gas spray that enhances the range of CO2 before it disperses into a useless mix of oxygen and gas. Within the canister, CO2 is pressurized to its liquid form, enabling more carbon dioxide to be stored in each canister. In order to utilize the extinguisher, the user must initially remove the red safety pin that is fastened to the handle.
To initiate the process, first detach the hose from the clip on the side of the extinguisher body. Direct the hose towards the base of the flames and then pull the handle to release the CO2 mixture stored in the canister. The release of pressure from the canister causes the CO2 to transform from a liquid to a gaseous state. This mixture will swiftly exit the hose and collide with the fire at the intended target. The primary objective of CO2 extinguishers is to suffocate the fire by eliminating oxygen in its nearby surroundings.
The use of CO2 extinguishers is highly effective in extinguishing fires by eliminating the fire tetrahedron. These extinguishers are particularly useful for class B and C fires, involving flammable liquids and electrical fires, respectively. In the case of class C fires, it is important to turn off the electric current before using CO2 extinguishers. The utilization of CO2 is greatly advantageous as it effectively suffocates the fire and hinders its access to surrounding oxygen.
When the user suppresses enough, the CO2 can completely cut off the fire from its O2, extinguishing it. Every fire needs fuel, oxygen, self-sustaining combustion, and heat to survive. When a CO2 extinguisher is used, it aims to remove the oxygen from this combination. As a result, self-sustaining combustion and heat become impossible, breaking the combination. The CO2 extinguisher also has the advantage of not leaving any harmful chemical residue.
This makes the CO2 extinguisher highly effective for putting out fires on valuable items, as well as humans or other organic targets, because you don’t have to worry about the chemical harming what you spray. However, the CO2 extinguisher does have limitations. It is not as effective in extinguishing Class A fires that involve materials like wood and other combustibles, as the CO2 residue dissipates quickly from the fuel, allowing the fire to continue burning by consuming more oxygen.
Furthermore, if a fire is larger and more severe, a CO2 extinguisher may not be sufficient to smother it effectively. In instances of a conflagration, it has been reported that Co2 extinguishers had minimal impact on the extensive flames and were substituted with foam and liquid-based extinguishing agents. Fortunately, the modern world is fortunate to have the most advanced firefighting technology ever. Fires that could completely destroy entire towns years ago now have no chance against our firefighters who utilize chemical agents to combat their spread.
By delving deeper into the history and utility of fire extinguishers, particularly the CO2 extinguisher, we can comprehend how carbon dioxide directly impacts the fire tetrahedron, ultimately dismantling it and extinguishing the fire. Although often overlooked in our everyday existence, it is anticipated that you now possess a heightened comprehension of the functionality of this life-preserving apparatus, leading to an increased admiration for its profound role in saving lives on a daily basis. Sources:
- http://www. firesafe. org. k/portable-fire-extinguisher-general/
- http://www. ehow. com/facts_5468750_carbon-dioxide-fire-extinguisher-information. html
- http://www. ehow. com/how-does_4886363_co-fire-extinguishers-work. html
- http://www. epa. gov/ozone/snap/fire/qa. html#qB11
- http://www. cofessco. com/images/Carbon-Dioxide-. pdf
- http://www. atwoodsecurity. com/fire-extinguisher-products-and-services/fire-extinguisher-history. html
- http://www. firesafe. org. uk/history-of-fire-extinguishers/
