origin
The world's first fire extinguisher was born in London on 1834. A fire almost completely destroyed the old Westminster Palace, where the British Parliament Building is located. Among many firewatch, there is one person who has not been idle to see the fire scene. He is George William Manby. Mamby was born in Norfolk. He joined the army when he was young, from officer to captain, and served as commander of Yarmouth Barracks. This idle position enabled him to devote himself to the cause of saving human lives that strongly attracted him. Previously, he was keen on shipwreck rescue. He invented the life buoy in the shape of trousers, and was the first person to put forward the identification signal by flashing the lighthouse. Later, Manby turned his genius from ocean rescue to fire rescue. He was trying on a fire suit when the fire broke out. His most outstanding pioneering contribution is the invention of a portable compressed gas fire extinguisher, which is a copper cylinder with a length of two feet, a diameter of eight inches and a capacity of four gallons, which is basically the same as today's fire extinguishers. He put the fire extinguisher in his specially designed trolley. He hopes that the patrol equipped with this fire extinguisher can immediately put out small fires at the scene of the fire, thus reducing the number of major fires. [ 1]?
use
Fire-fighting equipment is a kind of fire-fighting necessity that is often ignored at ordinary times and shows its talents when it is urgently needed.
Fire?Extinguisher?
Especially in today's high-rise buildings and indoor decoration, wood, plastic and fabric are widely used. Once a fire breaks out, there is no suitable fire extinguishing equipment, which may lead to great disaster.
In ancient times, fire fighting equipment was very simple, nothing more than hooks, axes, shovels, buckets and the like. The first real special fire extinguisher was invented by British captains Manby and Norfolk in 18 16. This is just one or two barrels filled with 1 water and compressed air.
By the middle of19th century, French doctor galil invented the portable chemical fire extinguisher. Mix sodium bicarbonate and water in a barrel, and put sulfuric acid in a glass bottle at the mouth of the barrel. When in use, the hammer breaks the bottle, so that the chemicals are mixed to produce carbon dioxide, which is discharged out of the barrel by water pressure.
1905, Professor Laurent of Russia invented a foam fire extinguishing agent in St. Petersburg. Aluminum sulfate is mixed with sodium bicarbonate solution, and stabilizer is added. Foam containing carbon dioxide produced after spraying floats on burning oil, paint or gasoline, which can effectively isolate oxygen and suffocate the flame.
1909, Davidson of new york obtained a patent. He used carbon dioxide to squeeze carbon tetrachloride out of a fire extinguisher, and this liquid immediately turned into a heavier nonflammable gas to extinguish the flame. Since then, small fire extinguishers such as dry powder fire extinguishers and liquid carbon dioxide fire extinguishers have appeared.
classify
There are many types of fire extinguishers, which can be divided into: portable and cart-type; According to the power source of driving fire extinguishing agent, it can be divided into: gas cylinder type, pressure storage type and chemical reaction type; According to the filling fire extinguishing agent, it can be divided into: foam, dry powder, haloalkane, carbon dioxide, clear water and so on.
dry-chemical fire extinguisher
Principle: Dry powder fire extinguisher is equipped with dry powder fire extinguishing agent. Dry powder extinguishing agent is dry and easy to extinguish fire.
dry-chemical fire extinguisher
The flowing fine powder consists of inorganic salt with fire extinguishing function and a small amount of additives, which are dried, crushed and mixed into fine solid powder. Blow dry powder (mainly containing sodium bicarbonate) with compressed carbon dioxide to extinguish the fire.
Structure: Dry powder fire extinguisher is powered by carbon dioxide gas or nitrogen gas, and sprays dry powder in the bottle to extinguish the fire. Dry powder is a kind of dry, easy-flowing fine solid powder, which consists of fire extinguishing base material, moisture-proof agent, flow promoter, anti-caking agent and other additives.
foam extinguisher
Principle: There are two containers in foam extinguisher, which are filled with aluminum sulfate and sodium bicarbonate solution respectively. The two solutions do not contact each other, and no chemical reaction occurs. (Never knock down foam extinguisher at ordinary times) When foam extinguisher is needed, turn the fire extinguisher upside down and mix the two solutions together, which will produce a lot of carbon dioxide gas:
Foam extinguisher principle
In addition to these two reactants, some foaming agents were added to the fire extinguisher. When the switch is turned on, foam is sprayed from the fire extinguisher and covered on the burning substance, so that the burning substance is isolated from the air and the temperature is reduced, thus achieving the purpose of extinguishing the fire.
Structure: The acid-base fire extinguisher consists of cylinder, cylinder cover, sulfuric acid bottle liner and nozzle. The steel cylinder is filled with sodium bicarbonate aqueous solution, and the sulfuric acid bottle is filled with concentrated sulfuric acid. There is a lead plug in the bottle mouth to seal the bottle mouth to prevent the concentrated sulfuric acid in the bottle from being diluted by water or mixed with the liquid medicine outside the bottle. The principle of acid-base fire extinguisher is to use the chemical reaction after mixing two chemicals to produce pressure to make the chemicals spray out, thus extinguishing the fire.
Carbon dioxide fire extinguisher
Principle: Liquid carbon dioxide is stored in the fire extinguisher bottle. When working, when pressing the handle of the bottle valve. The internal carbon dioxide extinguishing agent is sprayed from siphon to nozzle through bottle valve, which makes the oxygen concentration in combustion zone drop rapidly. When the carbon dioxide reaches a sufficient concentration, the flame will suffocate. At the same time, because liquid carbon dioxide will vaporize quickly, it will absorb a lot of heat in a short time, which will have a certain cooling effect on combustion products and help to put out the fire. Cart-type carbon dioxide fire extinguisher is mainly composed of bottle body, nozzle assembly, nozzle assembly and frame assembly, and the fire extinguishing agent in it is liquid carbon dioxide fire extinguishing agent.
Structure: The cylinder of carbon dioxide fire extinguisher is made of high-quality alloy steel through special technology, and its weight is reduced by 40% compared with that of carbon steel. It has the characteristics of convenient operation, safety, reliability, easy storage, portability and beauty.
Usage: It is suitable for extinguishing the initial fire of combustible liquid and gas, and can also extinguish the fire of live equipment. Commonly used in laboratories, computer rooms, power distribution stations and places with high maintenance requirements for precision electronic instruments, expensive equipment or articles.
Clear water fire extinguisher
The extinguishing agent in the clear water fire extinguisher is clear water. Water has low viscosity and high thermal stability at room temperature.
Water-based fire extinguisher type
With high density and high surface tension, it is an ancient and widely used natural fire extinguishing agent, which is easy to obtain and store.
Mainly rely on cooling and suffocation to extinguish the fire. Because every kilogram of water is heated from normal temperature to boiling point and completely evaporated, it can absorb 2593.4KJ of heat. Therefore, it uses its ability to absorb sensible heat and latent heat to cool down and put out the fire, which is incomparable to other fire extinguishing agents. In addition, the water vapor formed after water vaporization is an inert gas, and its volume will expand by about 1700 times.
When putting out a fire, the water vapor generated by water vaporization will occupy the space of the combustion zone, dilute the oxygen content around the combustion products, prevent fresh air from entering the combustion zone, and greatly reduce the oxygen concentration in the combustion zone, thus achieving the purpose of suffocating and extinguishing the fire. When water is sprayed, the specific surface area of water droplets and fog droplets will be greatly increased, thus enhancing the heat exchange between water and fire, thus strengthening its cooling and suffocation effects.
In addition, it can dilute some flammable and combustible liquids that are easily soluble in water; The water mist produced by strong jet can emulsify flammable and combustible liquid, make the liquid surface cool rapidly, and reduce the speed of combustible steam generation, thus achieving the purpose of fire extinguishing.
Simple fire extinguisher
Simple fire extinguisher is a portable fire extinguisher developed in recent years. Its characteristic is that the filling amount of extinguishing agent is below 500 grams and the pressure is below 0.8 MPa. It is a small fire extinguisher that can be used once and cannot be refilled.
According to the types of fire extinguishing agents, there are 12 1 1 simple fire extinguishers, also known as aerosol halon fire extinguishers; Simple dry powder fire extinguisher, also known as portable dry powder fire extinguisher; There is simple air foam extinguisher, also known as light air foam extinguisher. Simple fire extinguishers are suitable for home use. Simple 12 1 1 fire extinguishers and simple dry powder fire extinguishers can put out the initial fires of liquefied petroleum gas furnaces, angle valves on steel cylinders, or gas stoves, as well as fires caused by the burning of solid combustible materials such as hot pot fires and waste paper baskets. Simple air foam is suitable for initial fires caused by oil pans, kerosene stoves, oil lamps and candles, and can also put out fires caused by solid combustibles.
Simple fire extinguishers are more suitable for home, which is convenient to put out sudden fire.
Application mode
dry-chemical fire extinguisher
Scope of application: sodium bicarbonate dry powder fire extinguisher is suitable for the initial fire of flammable, combustible liquids, gases and charged equipment; Ammonium phosphate dry powder fire extinguisher can be used not only for the above kinds of fires, but also for the initial fire of solid substances. But they can't put out the fire of metal burning.
When using dry powder fire extinguisher to put out flammable and combustible liquid fires, the quasi-flame should be directed at the main parts. If the extinguished liquid fire is flowing and burning, the root of the quasi-flame should be shot from near to far, left and right, until all the flames are extinguished. If combustible liquid burns in the container, the user should shake the root of quasi-flame left and right to make the sprayed dry powder flow cover the whole opening surface of the container; When the flame is driven out of the container, the user should continue to spray until the flame is completely extinguished. When extinguishing the flammable liquid fire in the container, it is necessary to pay attention to the fact that the nozzle is not directly aimed at the liquid level to prevent the impact of the jet from splashing flammable liquid, which will expand the fire and bring difficulties to the fire extinguishing. If the flammable liquid burns in a metal container for a long time, the wall temperature of the container is higher than the self-ignition point of the flammable liquid, and it is easy to re-ignite after fire extinguishing. If we cooperate with foam extinguisher, the fire fighting effect will be better.
Usage: When putting out the fire, you can put the fire extinguisher on your hands or shoulders, quickly walk to the fire, and put it down about 5 meters away from the burning place. If you are outdoors, you should choose to spray against the wind. If the dry powder fire extinguisher used is of external pressure storage type, the operator should hold the spray gun tightly with one hand and lift the opening bail on the gas cylinder with the other hand. If the cylinder is opened by handwheel, loosen it counterclockwise, turn it to the highest position, and then lift the fire extinguisher. When the dry powder is ejected, it is quickly aimed at the root of the flame. If the dry powder fire extinguisher used is built-in gas cylinder or pressure storage type, the operator should first unplug the safety pin on the opening handle, then hold the nozzle at the front end of the spray hose, and press the opening handle with the other hand to open the fire extinguisher to extinguish the fire. When using a fire extinguisher with a spray hose or an accumulator fire extinguisher, always hold down the handle with one hand and never let go, otherwise the spray will be interrupted.
Precautions: When using ammonium phosphate dry powder fire extinguisher to extinguish solid combustible fire, it should be sprayed in the place where quasi-combustion is the fiercest, up and down, left and right. If conditions permit, the user can spray the fire extinguisher along the periphery of the combustion object, so that the dry powder extinguishing agent can be evenly sprayed on the surface of the combustion object until the flame is completely extinguished.
The use method of cart dry powder fire extinguisher is the same as that of portable dry powder fire extinguisher.
foam extinguisher
Scope of application: it is suitable for fighting general Class B fires, such as oil and grease fires, and can also be used for fighting Class A fires, but it cannot fight water-soluble flammable and combustible liquids, such as alcohols, esters, ethers, ketones and other substances in Class B fires; It is also impossible to put out live equipment and class C and D fires.
Portable usage: you can carry the lifting ring on the upper part of the cylinder and go to the fire quickly. At this time, care should be taken not to tilt the fire extinguisher excessively, nor to hold it horizontally or upside down, so as to avoid mixing the two chemicals and spraying it in advance. When the distance from the ignition point is about 10 meter, the cylinder can be turned upside down, with one hand holding the bail tightly and the other hand holding the cylinder bottom ring, aiming the jet at the combustion products. When putting out flammable liquid fire, if it is already flowing and burning, spray foam from far and near to make the foam completely cover the burning liquid surface; If burning in a container, the foam should be shot at the inner wall of the container, so that the foam can flow along the inner wall and gradually cover the fire surface. It is strictly forbidden to spray directly on the liquid surface, so as to avoid the burning liquid from being scattered or rushing out of the container due to the impact of the jet, and expand the combustion range. When putting out the fire of solid matter, the jet should be aimed at the place where the fire burns most violently. When putting out a fire, with the shortening of the effective spraying distance, users should gradually approach the burning area and always spray foam on the burning object until it is extinguished. When in use, the fire extinguisher should always be turned upside down, otherwise the spraying will be interrupted.
Portable foam extinguisher should be stored in a dry, cool, ventilated and convenient place, not near high temperature or places that may be exposed to sunlight to prevent carbonic acid from decomposing and failing; Anti-freezing measures should be taken in winter to prevent freezing; And should always wipe the dust, dredge the nozzle, keep unobstructed.
Push-cart foam extinguisher
Its adaptability to fire is the same as that of portable chemical foam extinguisher.
How to use the shopping cart: Generally, it is operated by two people. First push and pull the fire extinguisher to the fire point quickly, and stop at a place about 10 meters away from the fire point. After one person applies the spray hose, hold the spray gun tightly with both hands and aim at the burning place. The other is to turn the handwheel counterclockwise, so that the screw rises to the highest position, so that the bottle cap is completely opened, and then pour the steel bottle backwards, so that the pull rod touches the ground, rotate the valve handle 90 degrees, and spray foam to extinguish the fire. If the valve is installed at the spray gun, the person in charge of operating the spray gun will open the valve.
Cart-type foam extinguisher is suitable for fire, and the use method is the same as that of portable chemical foam extinguisher.
Carbon dioxide fire extinguisher
Scope of application: Carbon dioxide fire extinguishers are mainly used to put out initial fires of valuable equipment, archives, instruments and meters, electrical equipment below 600 volts and oil. When using, first lift the fire extinguisher to the fire site, put it down, pull out the safety pin, hold the handle at the root of the horn in one hand and the pressure handle of the switch valve in the other. For carbon dioxide fire extinguishers without spray hose, the horn should be pulled up 70-90 degrees. When using, you can't directly grasp the outer wall of the horn or the metal connecting pipe with your hands to prevent your hands from being frostbitten. When using a carbon dioxide fire extinguisher, if it is used outdoors, it should be sprayed in the upwind direction; If it is used in a narrow indoor space, the operator should leave quickly after fire fighting to prevent suffocation.
How to use it: only for fire fighting.
Carbon dioxide fire extinguisher
When lifting or transporting the fire extinguisher to the fire site, pull out the safety pin of the fire extinguisher about 5 meters away from the burning objects, hold the handle at the root of the horn with one hand and the pressure handle of the switch valve with the other hand. For carbon dioxide fire extinguishers without water hose, the horn should be at 70-90 degrees with the upper plate. When using, you can't directly grasp the outer wall of the horn or the metal connecting pipe with your hands to prevent your hands from being frostbitten. When putting out fire, when combustible liquid burns in a flowing state, the user sprays the jet of carbon dioxide extinguishing agent from near and far to the flame. If combustible liquid burns in the container, the user should raise the horn. Spray into the combustion container from the upper part of one side of the container. However, the carbon dioxide jet can not directly impact the surface of combustible liquid, which prevents combustible liquid from being washed out of the container, expands the fire and brings difficulties to fire fighting.
Attention:? When using a carbon dioxide fire extinguisher, if it is used outdoors, it should be sprayed in the upwind direction, and the hand should be placed on the wooden handle of the cylinder to prevent frostbite. If it is used in a narrow indoor space, the operator should leave quickly after fire fighting to prevent suffocation.
Others: Generally, the wheeled carbon dioxide fire extinguisher is operated by two people. When in use, two people push or pull the fire extinguisher to the burning place together, and stop at a distance of about 10 meter from the burning object. One person quickly took off the horn, unfolded the water hose, and then held the handle at the root of the horn. The other person quickly turned the handwheel counterclockwise to the maximum position. The fire extinguishing method is the same as the portable method.
Simple fire extinguisher
Usage 1
Portable: When using, you should take the handle of portable fire extinguisher or the fire extinguisher on your shoulder to the fire. Five meters to the left of the burning site.
Cart fire extinguisher
Yes, put down the fire extinguisher, pull out the safety pin first, hold the opening handle in one hand and the nozzle at the front end of the injection hose in the other. If the fire extinguisher has no spray hose, you can hold the opening handle with one hand and the bottom ring part at the bottom of the fire extinguisher with the other hand. Firstly, aim the nozzle at the burning place, and open the handle hard to make the fire extinguisher spray. When the rescued combustible liquid is flowing and burning, the user should aim at the root of the flame from near to far and from left to right and push it forward quickly until the flame is completely extinguished. If combustible liquid burns in a container, the quasi-flame should sweep from one side to the other. When the flame is driven out of the container, the jet should follow the flame until it is completely extinguished. However, it should be noted that the jet can not be directly sprayed on the surface of the burning liquid, so as to prevent the impulse of the extinguishing agent from rushing the flammable liquid out of the container, which will expand the fire and make it difficult to put out the fire. If the initial fire of combustible solid substances is put out, the jet should be aimed at the most violent place. After the flame is extinguished, measures should be taken in time to prevent reignition. 12 1 1 When using the fire extinguisher, it should not be inverted or placed horizontally, otherwise the fire extinguishing agent will not be sprayed out. In addition, when used outdoors, it should be sprayed in the upwind direction; When putting out a fire in a narrow room, the operator should evacuate quickly after the fire, because the extinguishing agent 12 1 1 is also toxic to prevent harm to human body.
Usage 2
Trolley type: Generally speaking, there are two operations when putting out a fire. First, push or pull the fire extinguisher to the fire site, and stop at a place about 10 meters away from the fire site. One person quickly loosens the spray hose, grasps the spray gun and aims at the burning place. The other man quickly opened the fire extinguisher valve. The fire extinguishing method is the same as the portable 12 1 1 fire extinguisher.