What are the contents of the ten prohibitions on fire and explosion prevention?

The basic purpose of fire and explosion prevention: to minimize casualties and property losses. Basic principles: prevent occurrence, limit expansion, extinguish fire and explosion. What are the contents of the top ten prohibitions on fire and explosion protection? This article is the information I compiled on the contents of the top ten prohibitions on fire and explosion prevention, for reference only. Contents of the ten prohibitions on fire and explosion prevention

Ten prohibitions on fire and explosion prevention, measures and contents:

(1) Smoking and carrying fire and flammable, explosive, and Toxic and corrosive items enter the production plant area.

(2) It is strictly prohibited to use fire for construction or domestic use in the production plant area without going through the fire-use procedures as required.

(3) It is strictly prohibited to wear clothing that easily generates static electricity to work in oil and gas areas.

(4) It is strictly prohibited to wear shoes with nails to work in oil and gas areas and flammable and explosive areas.

(5) It is strictly forbidden to use gasoline or volatile solvents to scrub equipment, clothing, tools and floors.

(6) Unauthorized motor vehicles of all types are strictly prohibited from entering the production equipment area, tank area and flammable and explosive areas.

(7) It is strictly prohibited to discharge flammable and explosive materials and chemical dangerous goods on site.

(8) It is strictly prohibited to knock, impact or work with ferrous metal or tools that are prone to sparks in oil and gas areas.

(9) It is strictly prohibited to block fire escapes and arbitrarily misappropriate or damage fire protection facilities.

(10) It is strictly prohibited to damage various explosion-proof facilities in the factory. Fire and explosion protection knowledge

Section 1 Fire Prevention

Fire prevention is a comprehensive technology involving a variety of engineering and technical sciences. It has a broad scope and complex technology, that is, people who need to engage in fire prevention work Professionals continue to research and explore, and leaders at all levels and the general public also need to attach great importance to it. Therefore, it is necessary to strengthen fire prevention publicity, education and management for people, popularize fire safety knowledge, and improve the fire prevention awareness of the whole people. Educate the masses to overcome paralysis and fluke mentality, consciously abide by disciplines and laws, and ensure fire prevention for everyone, at all times and everywhere. At the same time, we must master the common sense and basic methods of fire extinguishing to ensure that when a fire breaks out, we do not panic and put out the fire calmly and calmly.

1. Fire

Fire refers to the disaster caused by uncontrolled burning within a certain period of time or space.

(1) Fire types

1. Fire loss classification

According to the current fire statistics method, according to the casualties and affected households caused by a fire accident The number and amount of direct property losses can be divided into general fires, major fires and extraordinarily large fires. ; Those with fire losses lower than the above are considered general fires.

(1) Extraordinary fire: A particularly serious fire occurs when one of the following circumstances occurs: more than 10 people die (including the original number, the same below); more than 20 people are seriously injured; more than 20 people die or are seriously injured; 50 people are affected household or above; direct economic loss of more than 1 million yuan.

(2) Major fire: A major fire occurs if one of the following circumstances occurs: more than 3 people die; more than 10 people are seriously injured; more than 10 people die or are seriously injured; more than 30 households are affected; direct economic loss is 30 More than 10,000 yuan.

(3) Ordinary fire: Fires that do not have the first two conditions are ordinary fires.

2. Fire classification.

Class A fires refer to fires caused by the burning of solid combustible materials containing carbon, such as fires caused by the burning of wood, cotton, wool, hemp, paper, rubber, plastic and other substances.

Class B fires refer to fires caused by the burning of flammable liquids and meltable solid combustibles, such as burning of gasoline, kerosene, diesel, methanol, ethanol, ether, asphalt, paraffin and other substances. .

Class C fires refer to fires caused by the combustion of gas, such as coal gas, natural gas, liquefied petroleum gas, methane, ethane, hydrogen and other substances.

Class D fires refer to fires caused by the burning of active metals, such as potassium, sodium, magnesium, titanium, lithium, aluminum-magnesium alloys and other substances.

II. Basic measures for fire prevention

(1) Strengthen the education and management of personnel

(2) Strengthen the management of objects

(3) Strengthen the management of fire sources and power supplies

Section 2 Electrical Fire Prevention

1. Causes and preventive measures of electrical circuit fires

(1 ) Causes of fires in electrical circuits

Electrical circuits often produce sparks, arcs or overheat wires and cables due to short circuit, overload operation, excessive contact resistance, etc., causing fires.

1. Short circuit

On electrical circuits, due to various reasons, the current suddenly increases due to the connection and collision, which is called short circuit.

According to Ohm's law, due to the sudden decrease in resistance during a short circuit, the heat dissipation is proportional to the square of the current. When the short-circuit current suddenly increases, the instantaneous heat release is very large, which will greatly exceed the heat generated during normal operation of the line. Not only can the insulation be burned, but the metal can also be melted, causing nearby flammable and combustible materials to burn, causing a fire.

2. Overload

The amount of current that is allowed to pass continuously in an electrical line without overheating the wire is called the safe current carrying capacity or safe current. If the current exceeds the safe current value, it will It's called wire overload. Wire overload is generally based on temperature rise without considering voltage drop. The maximum allowable operating temperature of general wires is 65°C. When overloaded, the temperature of the wire exceeds this temperature value, which will accelerate the aging of the insulation and even damage it, causing a short circuit and fire accident.

3. Electric spark and arc

Electric spark is the result of discharge between electrodes. Sparks can occur when a wire is short-circuited or leaked, a switch is used to connect or cut off a circuit, a fuse is blown, a light bulb shakes or explodes, or a wire connection is loose, etc. The arc is composed of a large number of dense electric sparks, and its temperature can reach more than 3,000°C. Sparks and arcs can easily cause flammable materials to catch fire or explode.

4. Contact resistance is too large

When conductors are connected, the resistance formed on the contact surface is called contact resistance. If the joints are well treated, the contact resistance will be small; if the joints are not in good contact due to weak connections or other reasons, it will lead to excessive local contact resistance, overheating, discoloration or even melting of the metal, causing the burning of combustible materials in the insulation material.

Section 3 Fire Protection of Electrical Equipment

1. Lighting Equipment

Electric lighting is widely used in various fields of production and life. It is a device that uses electric energy to emit light. kind of light source. In the process of converting electrical energy into light energy, a large amount of heat is often generated and has a high temperature, so it has a certain fire risk. Electrical lighting is divided into two categories according to the principle of luminescence: thermal radiation light sources and gas luminescence light sources. Thermal radiation light sources mainly include incandescent lamps and tungsten halogen lamps; gas luminescent light sources mainly include fluorescent (daylight) lamps, high-pressure mercury lamps, neon lamps, etc. Electrical lighting is divided into: task lighting, decorative lighting and accident lighting according to the nature of use.

(1) Causes of fires in lighting equipment

1. The light bulb burns combustible materials

2. The light bulb breaks and catches fire

3. The ballast overheats and burns

4. High-temperature heat radiation bakes combustibles

5. The transformer of the neon light overheats and catches fire

(2) Fire prevention measures for lighting fixtures

In addition to selecting different types of lighting fixtures according to the fire risk of the environmental location, they should also meet the following fire protection requirements:

1. The high-temperature part of the surface of the luminaire is close to combustible materials When using, fire protection measures such as heat insulation and heat dissipation should be taken.

The lead-in wires of tungsten halogen lamps and incandescent bulbs with a rated power of 100W or above, ceiling lamps, trough lamps, and recessed lamps should be thermally insulated with non-combustible materials such as porcelain tubes, asbestos, and glass filaments.

2. Incandescent lamps, tungsten halogen lamps, high-pressure mercury lamps, ballasts, etc. exceeding 60W should not be installed directly on combustible decoration or combustible components. Combustible goods warehouses should not be equipped with high-temperature illuminators such as tungsten halogen lamps.

3. The distance between incandescent lamps, high-pressure mercury lamps and combustible materials and combustible structures should not be less than 50cm, and the distance between tungsten halogen lamps and combustible materials should be greater than 50cm.

4. It is strictly forbidden to use paper, cloth or other combustible materials to cover lamps. It is not advisable to stack flammable objects directly under the light bulb. Lighting fixtures outdoors or in some special places should have splash-proof facilities to prevent water droplets from splashing onto the surface of the high-temperature bulb and causing the bulb to burst. After the bulb is broken, it should be replaced in time or the metal head of the bulb should be unscrewed.

5. The voltage and capacity of the ballast and lamp must be the same and used together.

6. Concealed lamps and their heating accessories should be surrounded by non-combustible materials (asbestos boards or asbestos cloth) for fireproof and heat insulation treatment. When installation conditions do not allow, the surface of combustible materials should be painted with fire-resistant paint .

2. Motor

(1) Causes of motor fires

The main causes of motor fires are improper selection, improper use or poor maintenance. Some motors are of poor quality and have hidden dangers inside. They are prone to malfunctions and fires during operation.

1. Improper selection

In places with fire and explosion hazards, if a protective motor is selected, once the motor fails, high-temperature arcs or sparks will be generated, which will cause Explosive combustion of combustible materials or explosive mixtures.

2. Overload

The maximum power output of the motor is limited. If the load exceeds the rated output power of the motor, overload will occur. When overloaded, the motor will generate heat, vibration, speed decrease, abnormal sound, etc. When overloaded seriously, the motor will be burned.

3. Mechanical friction

There is friction during the rotation of the motor, the most prominent of which is bearing friction. After the bearing is worn, it will make abnormal sounds and cause local overheating and temperature rise.

4. Poor contact

The various contacts or wire contacts of the motor winding are not firmly connected. If they become loose and spark, it will cause a fire.

(2) Fire prevention measures for motors

1. Reasonably select the power of the motor

If the power of the motor is too small, the motor will be overloaded and the power will If it is too large, it will cause economic waste. Therefore, it is very important to choose the power of the motor reasonably.

2. Correctly select the type of motor

When selecting the type of motor, it should be determined according to the specific working environment. For example, when driving blowers, lathes, milling machines, drilling machines and other machinery and equipment, protective motors are often used.

3. Motor installation requirements

The motor should be firmly installed on a base of non-combustible materials, and combustibles should not be piled around it; there should be no space between the motor and buildings or other equipment. A channel with a clear distance of not less than 1m should be set aside.

4. Set up reliable protection devices

In order to prevent the motor from overloading, overheating and catching fire during operation, appropriate protection such as fuses and relays should be installed to avoid burning the motor.

5. Pay attention to supervision

For operating motors, monitoring of temperature rise, current and voltage should be strengthened. If abnormalities are found, they should be dealt with in a timely manner to prevent the accident from expanding.

6. Maintenance

The motor should be maintained frequently, check whether the motor wiring is firm, whether there is phase loss or moisture, and frequently clean the oil and dust on the motor.

7. Prevent the motor from under-voltage operation

When the power supply voltage of the motor drops below 70% of the rated voltage, it will cause the motor to fail to start or the running motor to stop, causing under-voltage. Running is very detrimental to the normal operation of the motor. Therefore, the motor should be prevented from running under voltage.

8. The grounding should be good

The metal shell of the motor should be well grounded, and the grounding wire must be solid and reliable. It is strictly forbidden to insert iron solders into the ground as grounding protection. The grounding resistance should not be greater than 10 ?.

Section 4 Fire Protection in Communication Equipment Rooms (Buildings)

1. Basic Fire Protection Requirements in Communication Equipment Rooms (Buildings)

1. Electrical equipment and power supply lines should be staffed by full-time Electricians install in accordance with specifications and implement a certified construction system.

2. All power cords in the communication equipment room should be copper wires, and closed junction boxes should be installed at the joints.

3. The cross-sectional area of ??the power line should be suitable for the load, and overload operation is not allowed.

4. It is forbidden to pull temporary power supplies randomly in the computer room and production site. When temporary wires must be mopped on the floor, double-sheathed wires must be used. The power wires cannot be fixed on iron nails or tied with metal wires.

5. Power cords and signal lines must not cross or penetrate air conditioning ventilation ducts. Power cords and signal lines should be laid separately. If they must be laid at the same time, the power cords should go through metal tubes or use armored wires.

6. Rated fuses must be used, and it is strictly prohibited to use copper, iron, or aluminum wire instead.

7. It is strictly prohibited to use high-heat lamps such as iodine tungsten lamps in communication equipment rooms. The distance between lamps and combustible materials should be greater than 0.5 meters. The ballast of the lamp cannot be installed on combustible or flammable materials, and it is strictly prohibited to install and use temporary lamps at will.

8. The generator room and battery room should use explosion-proof lamps and install exhaust equipment. Open flames and smoking are prohibited indoors, and the power switch should be located outdoors.

9. The power distribution frame must be clean and tidy, free of spider webs and dust, and the cables in the cable trench must be neat and free of water and debris.

10. UPS uninterruptible power supplies that have been powered for a long time should monitor their heating conditions to avoid fires and strengthen fire prevention measures.

11. Ten prohibitions in the main computer room: no smoking; no use of electric water heaters, electric stoves and other electric heating appliances; no storage of information unrelated to the equipment and other materials and items other than spare parts; no It is allowed to be used as a temporary warehouse; sofas are not allowed; unrelated persons are not allowed to enter; wires are not allowed to be pulled and wired randomly; flammable liquids such as gasoline are not allowed to be wiped on the floor; flammable and combustible liquids and gases are not allowed to be stored; Food is brought into the computer room.

2. Security protection measures for communication hubs against strong electricity and gas intrusion

1. The communication hub building and antenna should have good and reliable lightning protection facilities, and their lightning protection facilities The resistance of the device and down-conductor should not be greater than 10 ohms. The ground resistance should be tested every year before the thunderstorm season. If it fails, it should be rectified in time.

2. It is recommended that the ground wire of the lightning protection device and the ground wire of the equipment, signal line, and power cord be connected in accordance with the joint grounding requirements.

3. The security protection devices in the communication room to prevent strong current intrusion must be tested and maintained regularly. If the security devices are damaged or slow and ineffective, they must be replaced in time.

4. In order to prevent gas intrusion, the cable entry room should be blocked and a gas concentration alarm should be installed.

3. Equipment room decoration and internal safety management of the hub building.

1. The communication equipment room is not allowed to be decorated with flammable materials such as wooden boards, fiberboards, polyboards, plastic boards, and polystyrene foam.

2. Suspended ceilings, partition walls, air-conditioning ventilation ducts, doors, windows, curtains, etc. should all be made of non-combustible materials; new equipment rooms only consider equipment and process requirements and do not have suspended ceilings. Anti-static activities are not used unless there are special requirements on the ground. floor.

3. For decorations that have been decorated with flammable and combustible materials, they must be dismantled or treated with fire retardant coatings to improve the fire resistance level.

4. Warehouses, dance halls, karaoke halls, communication hub buildings above the county level and telephone communication production buildings with more than 10,000 doors are not allowed in the communication building. Staff dormitories (including single dormitories) are not allowed.

5. Construction within the communication hub building must have a strict approval system, a safety agreement must be signed with the construction department, and fire safety management must be strict.

4. The communication equipment room shall be separated into fire prevention areas. All cable shafts and holes in the building must be blocked, and central air conditioning and ventilation ducts must be installed and managed.

1. The computer room and the computer room, and the computer room and the office area must be separated by fire prevention areas.

2. Cable shafts and pipes in the building should be sealed with non-combustible materials at each floor. No combustible materials should be used in shafts and access doors.

3. When the central air-conditioning ventilation duct passes through the partition wall or floor of the machine room, a fire valve should be installed on the horizontal pipe connecting with the vertical main air duct.

4. Non-combustible materials such as aluminum silicate and slag wool should be used as insulation materials for ventilation ducts.

5. Strengthen the management of flammable and explosive items.

1. Smoking is strictly prohibited in communication equipment rooms and production sites.

2. Packing boxes, newspaper strips, printing paper and other flammable items in the corridors and computer rooms must be cleaned at any time and must not be accumulated.

3. Strictly manage open flames. Open flame operations must be reported to the security department for approval, a "Fire Permit" must be issued, and safety precautions must be formulated.

4. Small amounts of gasoline, kerosene, acetone and other flammable liquids that must be used for equipment maintenance should be stored in limited quantities and strictly managed.

5. It is not allowed to clean equipment in the communication equipment room, and it is not allowed to use flammable liquids such as gasoline to wipe the floor; when using a small amount of flammable liquids such as gasoline to wipe equipment contacts, it should be done without electricity, such as Reliable fire prevention measures must be taken during live operation.

Section 5 Fire Fighting

The "Fire Protection Law of the People's Republic of China" stipulates: When discovering a fire alarm, any unit or individual should report to the police quickly and accurately, and Actively participate in the fight. The fire unit must organize forces in time to put out the fire. Neighboring units should actively provide support. After receiving the alarm, the fire brigade must rush to the fire scene and put out the fire in time. The key issue of assigning the responsibility for timely fire fighting to the unit was clearly raised.

1. Organize efforts to put out fires in a timely manner

To put out fires, we must strive to extinguish them early, put them out small, and extinguish them, and put out the fire in its initial stage.

(1) It is necessary to carefully formulate firefighting plans for communication equipment rooms and production sites, and clarify the emergency measures that should be taken by each equipment room and each position in the event of a fire, so as to avoid panic in the event of a fire and delay the fighter's opportunity.

(2) The most favorable opportunity to put out the initial fire in a timely manner is within 5-7 minutes of a building fire. Unit leaders are required to organize employees to put out fires within 5-7 minutes of discovering a fire.

(3) Automatic fire alarm devices must be installed in communication equipment rooms and important sites. At the same time, the duty patrol responsibilities must be strengthened to strive for early detection of fire alarms. The following must be done:

1. Have police Must report

2. Remember the alarm phone number: 119, remember the location of the alarm phone

3. Master the content and procedures of the alarm: be calm and explain the unit, address, and phone number , burning parts, properties of burning materials, and send people to meet fire trucks at intersections

(4) Fire extinguishing

First find out the fire and the way the fire develops and spreads. The method is: three checks, three views and five determinations. The third check is to check whether anyone is trapped in the fire scene, the second check is to check what materials are burning, and the third check is to check where the fire scene is closest.

The first step is to look at the smoke to determine the direction, intensity, and nature of the fire; secondly, look at the building to determine the structure and access; thirdly, look at the environment to determine the focus, combat power, and route, and then quickly and decisively determine the fire extinguishing strategy:

1. Indoor fire, internal attack and close combat.

2. Building fire, intercept in layers.

3. In case of fire on the upper floor, the lower floor is fortified.

4. Fire in low-rise buildings, nearby high-rise buildings must be fortified.

5. If there is a large fire, set up defenses downwind and at high places.

6. If a building with metal brick and wood structure catches fire, prevent the whole building from suddenly catching fire. The distribution of combat power must be such that: fire extinguishing and rescuing people are carried out simultaneously; the fire extinguishing department should use the main force to directly extinguish the fire, and at the same time use a small part of the force to set up defenses in places where it may spread to prevent the fire from spreading; when the fire has expanded, it should be The main force is used to intercept fires or potentially cause greater disasters.

(5) Organize full-time and volunteer fire brigade to use fixed fire-extinguishing devices and fire extinguishers to extinguish fires.

1. When spraying water, the water should be sprayed to the root of the flame, that is, the water should be sprayed on the burning object and not on the flame. When the flame cannot be seen, do not spray water blindly. According to the fire scene The combustion conditions change the jet in time.

2. Spray foam. Use foam to extinguish liquid fires. It is not advisable to spray directly onto the flames. Instead, start from close by, spray the left and right sides at the same time, and then advance deeper into the fire.

3. When spraying dry powder and 1211, the spray should be aimed at the root of the flame in parallel. If the flame area in the burning zone is large, the dry powder and 1211 can be parked upwind or sideways at a distance of 5 meters from the fire source. position, control the dry powder, 1211 to swing slightly parallel to the left and right sides, so that the fire extinguishing agent completely covers the burning area; when spraying dry powder, 1211 towards burning objects with shielding materials, you should be condescending, otherwise it will be difficult to extinguish. To put out a fire, you must first cut off the power supply to the fire site. However, sometimes in order to buy time, you can use a fire extinguisher with electricity to put out the fire at the initial stage of the fire. However, you must first cut off the power supply to the fire site when spraying water on the fire site.

2. Fire extinguishing methods

We know that combustion requires three conditions: combustibles, combustion-supporting materials and ignition sources. According to this principle, all fire extinguishing methods are to destroy the combustion conditions and stop the combustion reaction. There are four basic methods of fire extinguishing: cooling fire extinguishing method - reducing the temperature of burning substances; suffocation fire extinguishing method - reducing the oxygen content in the air. ; Isolation fire extinguishing method - Isolate combustible substances close to the fire source; Suppression fire extinguishing method - eliminate free radicals in the combustion process.

(1) The cooling fire extinguishing method is based on the condition that combustible materials must reach a certain temperature for combustion to occur. The fire extinguishing agent is sprayed directly on the combustible materials to reduce the combustible materials below the ignition point, thereby stopping the combustion. Use water and carbon dioxide to extinguish fires. Their main function is to cool down and extinguish fires. Generally, water can be used to cool and extinguish fires caused by substances.

(2) The suffocation fire extinguishing method is based on the condition that the combustion of combustible substances requires sufficient combustion aids, such as air (or oxygen), to take appropriate measures to prevent air from entering the combustion zone, or to dilute it with inert gas The oxygen content in the air makes the burning material lack or cut off oxygen and extinguish. When using suffocation methods to put out fires at the fire site, you can use asbestos cloth, soaked quilts and other non-combustible or refractory materials to cover the burning objects or close the holes, such as using a metal pot lid to cover the oil pot to extinguish the fire. When fighting an initial fire, the doors and windows of the building on fire are generally not opened until preparations are made to put out the fire, in order to prevent fresh air from entering and flooding the room with foam.

(3) Isolation fire extinguishing method is to isolate or evacuate burning objects from nearby combustible materials to stop burning. This method is suitable for fighting various solid, liquid and gas fires.

Specific measures include: moving flammable and explosive items near the fire source from the burning area to a safe location: closing valves to prevent flammable gases and liquids from flowing into the burning area; removing flammable and explosive materials adjacent to the fire site. Burn the building structure and create a space zone that prevents the spread of fire.

(4) The suppression fire extinguishing method is to spray chemical fire extinguishing agents into the burning area to participate in the chemical reaction of combustion, thereby stopping the burning reaction. In this method, the main fire extinguishing agents used are dry powder and halogen Fire extinguishing agents such as burning, 1211, 1031, etc. To suppress the combustion reaction, enough fire extinguishing agent must be accurately sprayed in the combustion zone to block the combustion reaction. At the same time, necessary cooling and cooling measures must be taken to prevent re-ignition.

3. Fire extinguishing agent

Substances that can effectively destroy burning conditions and terminate combustion are called fire extinguishing agents. The basic requirements for fire extinguishing agents are: high fire extinguishing efficiency, easy to use, and basically harmless to humans and materials.

(1) Types of fire extinguishing agents

There are many types of fire extinguishing agents. Commonly used ones include water, foam, carbon dioxide, dry powder, haloalkanes, haloalkyl substitute fire extinguishing agents, sand, and water. Steam etc.

1. Water

Water is the most widely used fire extinguishing agent. Water can quickly cool burning materials. Each kilogram of water completely vaporized can absorb 539 kcal of heat. Water can isolate air and suffocate combustion. When water is sprayed on the fuel, part of it turns into water vapor, reducing the oxygen content in the combustion zone. Water is a commonly used fire extinguishing agent that is both economical and affordable. However, water cannot extinguish fires caused by the following substances and equipment: (1) oil fires that are lighter than water, such as petroleum, gasoline, benzene and other oils that can float on the water; (2) dangerous chemicals that can burn or explode when exposed to water, such as Fires involving metal hobs, pots, aluminum powder, calcium carbide, etc.; (3) Fires involving molten iron, molten steel, hot metal and slag, etc.; (4) High-voltage electrical equipment; (5) Precision instruments and equipment and valuable documents and archives.

2. Chemical foam

The chemical foam used in fire extinguishers is a film formed by the interaction of acidic substances (aluminum sulfate) and alkaline substances (bicarbonate) and foam stabilizers. group of bubbles. It can cover the burning liquid surface or object surface, prevent flammable or combustible liquid vapor from entering the combustion zone, prevent air from contacting the liquid surface, and prevent heat from being transferred to the liquid surface, thereby terminating combustion. Foam is the most economical and effective fire extinguishing agent for extinguishing flammable and combustible substances. However, foam contains water and cannot extinguish water-resistant substances and electrically charged objects. Foam cannot be used in combination with dry powder, because dry powder can quickly destroy the foam covering layer. When extinguishing large-area fires, protein-based foams and synthetic foams (such as soluble foam and high-expansion foam) are usually used. When fighting fires involving water-soluble liquids such as alcohol, acetone, and vinegar, Dissolved air foam should be used to extinguish the fire.

3. Dry powder

The main ingredient of dry powder fire extinguishing agent is hydrogen carbonate and other salt substances, and is mixed with some lubricants and moisture-proof agents. When dry powder is used to extinguish a fire, it can form an isolation layer that hinders combustion. At the same time, the dry powder particles can absorb combustion active particles and play a role in interrupting the combustion chain reaction. It can also decompose non-combustible gases and dilute the oxygen content in the combustion zone. Therefore, dry powder has fast fire extinguishing speed, low toxicity and can be stored for a long time. Dan cost is relatively low and it is one of the most widely used fire extinguishing agents.

Use dry powder to extinguish fires. It does not have a cooling effect. In large-area fire scenes, "backburning" is prone to occur. Dry powder fire extinguishing agents should not be used in places with dust hazards to prevent the deposited dust from being blown away. In addition, dry powder fire extinguishing agents cannot be used to extinguish precision instruments.

4. Halogenated alkyl fire extinguishing agents

Halogenated alkyl fire extinguishing agents are made by replacing hydrogen atoms in carbon oxides, methane or ethane with atoms of halogen elements such as fluorine, chlorine and australia. composed of certain compounds. The commonly used ones are 1211, which is "difluoromethane" and 1301, which is "trifluoromethane". They are all colorless gases, which are liquefied by pressurization and placed in bottles. When the switch is turned on, the gases are sprayed out in the form of mist, interrupting the combustion chain reaction and inhibiting combustion. Its fire extinguishing efficiency is 5 times higher than carbon dioxide.

Low toxicity and leaves no trace. Halonated alkyl fire extinguishing agents are used to extinguish fires involving petroleum and its products, organic solvents, live equipment, precision instruments, cultural relics, archives and other items. However, compared with other fire extinguishing agents, haloalkane fire extinguishing agents are more expensive.

5. Halogenated alkyl substitutes

(1) Heptafluoropropane (FM200)

Heptafluoropropane (FM200) fire extinguishing agent is colorless, odorless, non-conductive and non-toxic. pollution. The ozone depletion potential (ODP) is zero, which complies with environmental protection requirements. Its toxic and side effects are smaller than those of haloalkyl fire extinguishing agents. It is an ideal substitute for haloalkyl fire extinguishing agents. Heptafluoropropane (FM200) fire extinguishing agent has the advantages of high fire extinguishing efficiency, no damage to equipment, good electrical insulation, and rapid fire extinguishing. Heptafluoropropane (FM200) fire extinguishing agent does not contain particles and oily substances after release, and does not damage the environment. After the fire is extinguished, the fire extinguishing agent can be promptly ventilated and quickly removed, and normal conditions can be quickly restored.

(2) Inert gas (IG541)

IG-541 fire extinguishing agent is composed of nitrogen (N2, 52), argon (Ar, 40) and carbon dioxide (CO2, 8) It is a colorless, odorless and non-toxic mixed gas composed of three gases. It does not destroy the ozone layer of the atmosphere and has no adverse effects on the environment. It is non-conductive, clean during the fire extinguishing process, and leaves no traces after the fire is extinguished. IG-541 is a total submergence system, suitable for extinguishing Class A (surface fire), B, C and electrical fires, and can be used to protect frequently occupied places.

(3) Carbon dioxide

Carbon dioxide is a colorless, inert gas that does not burn, does not support combustion, and is heavier than air. A carbon dioxide fire extinguisher is made by filling carbon dioxide gas into a bottle under high pressure. When the valve is opened during use, the gas will spray out in the shape of snowflakes and quickly vaporize to extinguish the fire. Its characteristics are that it is non-conductive and leaves no stains. Suitable for fighting electrical equipment, precision instruments, archives, etc. It is not effective for collective combustion materials, such as firewood, cotton, wood, etc., and cannot extinguish fires caused by metal pots, pots, pots, aluminum and other substances that react with carbon dioxide. Use it to extinguish fires indoors. When the content reaches 5, people will find it difficult to breathe.

6. Sand and soil

Sand and soil are economical and commonly used fire-extinguishing materials. Its fire-extinguishing principle is to cover the flame and isolate the burning material from the air to achieve the fire-extinguishing effect.

7. Water vapor

When the filling water vapor content in the combustion zone reaches 35, the combustion will be stopped.