Introduction to Fire Protection and Emergency Services
You wake to a strong smell of burnt wood, and your vision is blurred to the point you aren’t quite sure whether or not you are in a dream, or if this is truly happening to you. As you jump out of bed the floor feels warmer against your bare feet than normal and it hits you what is occurring- your home is on fire. You sprint to the door and feel the handle; it is cold to the touch so you swing open the door, anxiety and adrenaline coursing in every action you perform.
With the door open, you notice an object strapped to your wall, an object you overlook every day but for this day, its existence fills you with hope. You sprint to the wall and rip the object of the wall, and head downstairs to see what burning inferno awaits you. As you reach the landing and turn you see what has caused the massive amount of smoke and heat- the curtains have erupted in flames directly above a power outlet, smothered by an overabundance of extension cords and power strips.
Using the apparatus in your hands, you follow its simple instructions, aim its hose, and pull the trigger.
In mere minutes the fire has been smothered and your house is no longer in jeopardy of being engulfed in flames. You crumple to the floor and take a much needed, smoke-free breath of relief as you stare at the instrument that potentially saved your life- your fire extinguisher. This normal, house-hold item can be found in almost every house across the U. S. , but how much do we really know about this object, or its capabilities? In this report, I will talk about the functions and use of the household fire extinguisher, more specifically, the CO2 fire extinguisher.
Fire extinguishers have the common misconception of being relatively new technology, which is simply not the case. The first fire extinguisher has been around since the early 18th century in England. A chemist by the name of Ambrose Godfrey created a gunpowder activated extinguisher, for which he was greatly celebrated for. This device was simply a pewter chamber filled with a fire-extinguishing liquid, backed by a small chamber of gunpowder and fuses. Upon the pull of a trigger, the fuses would light, setting off the gunpowder and consequently discharging the chemical agent out of the business-end of the apparatus.
This extinguisher was unfortunately a one-time use, but it was proven to be quite effective in the multitude of fires encountered in London during the 1700’s. As time went on the fire extinguisher saw a myriad number of alterations and modifications. One version that should be noted is the soda-acid extinguisher of 1866. Created by Francis Collier of France, this fire extinguisher sported a canister of water and sodium bicarbonate. Within this solution floated a capsule full of sulfuric acid. When the extinguisher was needed, the user would break the capsule, either by a plunger or pull-cord, and aim the hose at the base of the fire.
Once the sulfuric acid mixed with the bicarbonate solution, reactions would take place, producing mass amounts of carbon dioxide. This event would in turn cause a massive buildup of pressure within the canister, consequently firing the solution out of the hose and onto the fire. Although the soda-acid extinguisher did not directly use the carbon dioxide to smother the fire, the fact that CO2 was implemented into the device makes it the father of the current CO2 fire-extinguishers. As building constructions changed with the times, so did the need for different fire extinguishers.
In 1904 Aleksandr Loran devised the first chemical foam extinguisher. With electrical fires becoming a rising issue in residential areas, this foam extinguisher did a great job of putting said fires out of commission without putting the user in jeopardy with the inclusion of a conductible liquid agent. The carbon dioxide fire extinguisher that we know and use today was invented in 1924 by Walter Kidde. The birth of this apparatus was brought on by the cry of help from Bell Telephones Company’s request for an extinguisher that used a non-conductive chemical for thwarting previously hard-to-kill fires found in telephone switchboards.
The original version of the device sported a 7. 5lb canister with a wheel valve located on top, and a cloth insulated hose attached to aim the gas as it exited the canister. This extinguisher was just what the telephone company was looking for and rocketed the Co2 extinguisher into fame and wide use throughout multiple businesses. It should be noted that a main industry that picked up the CO2 extinguisher was the movie business, as it could be used to extinguish stunt actors without covering them in possibly poisonous agents or messy residue.
As time went on the wheel valve technology was replaced with a hand trigger device that is seen on most fire extinguishers, and the cloth-covered hose was replaced with a rubber insulated hose. Some versions even feature a cone-like nozzle attached to the end of the hose to create a more conic spray of gas while increasing the distance the CO2 can reach before dissipating to a useless mixture of oxygen and gas. Within the canister the CO2 is pressurized to its liquid state, allowing more carbon dioxide to be filled into each canister. To use the extinguisher, the user must first pull the red safety pin attached to the handle.
Then, pull the hose off of the clip on the side of the body of the extinguisher and aim at the base/origin of the flames. Once the hose is aimed, the user should then pull the handle, releasing the CO2 mixture from the canister. As the liquid travels out of the canister and into the hose/environment, pressure placed on the CO2 is relieved dramatically and the CO2 enters a more gaseous state rather than liquid state. This colloidal mixture will accelerate out of the hose/funnel, and hit the fire where aimed. The entire purpose of CO2 extinguishers is to smother the fire and remove oxygen from its immediate vicinity.
This effectively destroys the fire tetrahedron and ultimately puts the fire out. CO2 Extinguishers are especially useful for class B and C fires. Class B fires are flammable liquids and Class C fires are electrical fires. It should be noted that for Class C fires, while the CO2 does an effective job putting the fire out, the electric current should be turned off before using the extinguisher. What makes CO2 so useful is that it does a fantastic job of smothering the fire and continuing to keep it removed from all oxygen in the environment.
With enough suppression from the user, the CO2 will completely cut off the fire from its O2, causing the fire to die. Every fire needs the tetrahedron to survive, which includes: the fuel, oxygen, self-sustaining combustion, and heat. When a CO2 extinguisher is utilized, its purpose is to remove the oxygen facet from the tetrahedron. By doing so, the self-sustaining combustion is no longer possible, meaning heat is no longer possible, leaving the tetrahedron completely broken. Another useful characteristic about the CO2 extinguisher is the fact it does not leave any harmful chemical residue on whatever the chemical contacts.
This makes the extinguisher very useful for combating fires on expensive items, as well as humans or other organic targets, because there is no need to worry about possible harmful side effects from the chemical hurting what you spray. Although the CO2 extinguisher is a very well-rounded fire combatting device, it is not without its drawbacks. Class A fires that included materials such as wood and other combustibles are very difficult to put out with a CO2 extinguisher as the CO2 residue quickly dissipates from the fuel, leaving the fire room to burn more oxygen for self-sustainment.
Also, larger, more severe fires may be too large for a CO2 extinguisher to effectively smother the fire. In the case of a conflagration, reports have stated that Co2 extinguishers utilized had little to no effect on large-scale flames and were substituted for foam and liquid-based extinguishing agents. Today’s world is lucky to boast the most effective firefighting technology in all of history. Fires that, decades ago, would consume and burn whole entire towns to the ground stand no chance against our firefighters today thanks to massive advancements in our use of chemical agents to combat the spread of fires.
By looking more into the history and use of fire extinguishers, more specifically, the CO2 extinguisher, we can see exactly how carbon dioxide directly affects the fire tetrahedron and consequently breaks it down to ‘kill’ the fire. These sorts of devices go unnoticed in our daily lives, but hopefully now you have a better understanding of how this life-saving device works, and therefore a greater appreciation for what it does to save lives every day. 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/
Cite this Co2 Fire Extinguisher Research
Co2 Fire Extinguisher Research. (2016, Sep 18). Retrieved from https://graduateway.com/co2-fire-extinguisher-research/