What kind of material fires are suitable for dry chemical fire extinguishers

Gas fire extinguishing is a fire extinguishing system that uses a gaseous extinguishing agent, usually at room temperature and atmospheric pressure. Generally, it is composed of a fire extinguishing agent storage bottle, a control starting valve group, a transmission pipeline, a nozzle and a fire detection control system, as well as an inert gas storage bottle for pressurized drive. Usually according to the gas fire extinguishing agent used, there are halide fire extinguishing system, carbon dioxide fire extinguishing system and steam fire extinguishing system.

In order to protect some parts that cannot be extinguished with water and avoid fire losses, gas fire protection is widely used. Such as telecommunications room, radio and television equipment, generator room, electrical equipment room, transformer, oil circuit breaker, motor, internal combustion engine, electrical room, library and archive building, scientific research test building, valuable instrument and equipment room, large ships, oil plant and other places. The gas fire extinguishing system includes heptafluoropropane 、...

Dry powder fire extinguishers are also called ABC fire extinguishers;

Applicable to the first three types of fires in fires:

Class A fire: refers to a fire of solid matter. This substance is usually organic in nature and can produce burning embers when burned. Such as wood, hay, coal, cotton, wool, hemp, paper and other fires.

Category B fire: refers to a fire of liquids or meltable solid substances. Such as kerosene, diesel, **, methanol, ethanol, asphalt, paraffin, plastic and other fires.

Class C fire: refers to a gas fire. Such as gas, natural gas, methane, ethane, propane, hydrogen and other fires.

Dry powder fire extinguishers are mainly suitable for the initial fire of flammable and combustible liquids, gases and live equipment, and can also extinguish the initial fire of solid substances, but cannot extinguish metal combustion fires.

The dry powder fire extinguisher can be used in combination with fluoroprotein foam fire extinguishing agent and water film-forming foam fire extinguishing agent to extinguish the initial disaster of the oil tank, quickly control the development of the flame, and play a role in rapid fire extinguishing. Dry powder fire extinguishers are widely used in oil fields, oil depots, refineries, chemical plants, chemical warehouses, ships, airports and industrial and mining enterprises.

Precautions for the use of dry chemical fire extinguishers.

1. Pay attention to the status of the pressure gauge.

The green zone on the disc of the fire extinguisher pressure gauge indicates normal usability, the red zone indicates that the negative pressure is not available, and the yellow zone indicates that the pressure is too high, the equipment is in an unstable state, and high temperature or impact may cause pressure relief jet.

2. Precautions for spraying.

When spraying, stand upwind and spray, aim the nozzle at the root of the flame, swing left and right, advance quickly, and leave no residual fire. When extinguishing oil liquid fires, do not directly impact the liquid level to prevent oil splashing, causing expansion of the potential and causing fire extinguishing difficulties.

Scope of application of dry powder fire extinguisher: sodium bicarbonate dry powder fire extinguisher is suitable for the initial fire of flammable, combustible liquid, gas and live equipment; In addition to the above-mentioned types of fires, ammonium phosphate dry powder fire extinguishers can also be used to extinguish the initial disaster of solid substances. But none of them can extinguish metal burning fires.

When the dry powder fire extinguisher extinguishes a combustible and flammable liquid fire, it should be aimed at the flame point, and if the liquid fire to be extinguished is flowing and burning, it should be aimed at the root of the flame from near to far, and swept left and right until the flame is completely extinguished. If the flammable liquid burns in the container, the user should aim at the root of the flame and shake it left and right to strafe so that the ejected dry powder stream covers the entire surface of the container opening; When the flame is driven out of the container, the user should continue to spray until the flame is completely extinguished.

When extinguishing the fire of the combustible liquid in the container, it should be noted that the nozzle should not be sprayed directly at the liquid level, so as to prevent the impact of the jet from splashing out the combustible liquid and expanding the fire, resulting in difficulty in extinguishing the fire. If the combustible liquid burns in the metal container for too long, the wall temperature of the container is higher than the spontaneous ignition point of the combustible liquid, which is easy to cause the phenomenon of re-ignition after extinguishing the fire.

It is used to extinguish the initial disaster of petroleum and its products, combustible gas, and electrical equipment.

Dry powder fire extinguisher is a kind of fire extinguisher, which can be divided into ordinary dry powder fire extinguishers according to the type of dry powder fire extinguishing agent; Ultra-fine dry powder fire extinguisher.

Ordinary dry powder fire extinguishing agent is mainly composed of active fire extinguishing components, hydrophobic components and inert fillers, hydrophobic components mainly include silicone oil and hydrophobic silica, and there are many types of inert fillers, which mainly play the role of anti-vibration and agglomeration, improve the movement performance of dry powder, catalyze the polymerization of dry powder silicone oil and improve the compatibility with foam fire extinguishing agent. This kind of ordinary dry powder fire extinguishing agent has been widely used at home and abroad.

Dry powder fire extinguishing agent is a dry and easy-to-flow fine powder used for fire extinguishing, which is composed of inorganic salts with fire extinguishing effect and a small amount of additives that are dried, crushed and mixed into fine solid powder. It is a fire extinguishing agent that is widely used in fire fighting and is mainly used in fire extinguishers. In addition to the special dry powder chemical fire extinguishing agent for fighting metal fires, dry powder fire extinguishing agents are generally divided into two categories: BC dry powder fire extinguishing agent (sodium bicarbonate) and ABC dry powder (ammonium phosphate).

First, the volatile decomposition of inorganic salts in the dry powder is chemically inhibited and negatively catalyzed by the free radicals or active groups produced by the fuel during the combustion process, so that the chain reaction of combustion is interrupted and the fire is extinguished;

Second, the powder of dry powder falls outside the surface of combustibles, undergoes a chemical reaction, and forms a glass-like covering layer under the action of high temperature, thereby isolating oxygen, and then suffocating and extinguishing fires. In addition, there is a partial dilution of oxygen and cooling.

Portable dry powder fire extinguisher, also known as ABC fire extinguisher, is suitable for three types of disasters: Class A fire, Class B fire, and Class C fire.

The dry chemical fire extinguisher uses liquid carbon dioxide or nitrogen as the power to drive the dry chemical fire extinguishing agent in the fire extinguisher to spray out the fire extinguisher. As a commonly used fire extinguishing equipment for extinguishing initial fires, there are two common types: BC and ABC. When equipped with this type of fire extinguisher, different types of dry powder fire extinguishers should be selected according to the specific use, mainly according to the combustion of combustibles in the place of use.

1. BC dry powder fire extinguisher. This type of fire extinguisher is filled with BC dry powder and can extinguish BC fires. It is suitable for the initial fire of flammable and combustible liquids, gases and live equipment, and is not suitable for the fire of solid substances.

Therefore, in the power distribution room, kitchen, computer room and other places prone to combustible liquid gas fire and live fire, BC dry powder fire extinguishers can be equipped. Of course, such places can also be equipped with ABC dry chemical fire extinguishers.

2. ABC dry powder fire extinguisher. This type of fire extinguisher can extinguish solid, liquid and gas fires and has the widest range of applications. It can be used in all kinds of public places, office places, hotels, restaurants, cars, ships and even homes, but it shall not be used to extinguish fires of light metal materials.

How to use dry powder fire extinguisher:

Remove the seals; unplug the safety pin;

Holding the nozzle in his left hand and the pressure handle in his right hand;

At a distance of 2 meters from the flame, the right hand presses down the pressure handle, and the left hand holds the nozzle and swings it left and right, spraying dry powder to cover the entire combustion area.

Uses of carbon dioxide fire extinguishers:

It is suitable for all kinds of flammable, combustible liquid and combustible gas fires, and can also extinguish the initial disasters of instrumentation, books and archives, craftsmen and low-voltage electrical equipment.

How to use carbon dioxide fire extinguishers:

Remove the seals; unplug the safety pin;

Stand 2 meters away from the fire source, hold the horn barrel in your left hand, and press down the pressure handle with your right hand;

Spray at the root of the flame and push forward until the flame is extinguished;

Uses of foam fire extinguishers:

It is suitable for extinguishing all kinds of oil fires, wood, fiber, rubber and other solid combustible fires.

How to use a foam fire extinguisher:

Cover the nozzle with your right hand and hold the bottom edge of the barrel with your left hand;

Turn the fire extinguisher upside down in a vertical state, shake it up and down a few times, and then release the nozzle;

Grasp the barrel lug with the right hand, grasp the bottom edge of the barrel with the left hand, put the nozzle towards the combustion area, stand 8 meters away from the fire source and spray, and continue to advance, around the flame spray, until the flame is not extinguished;

After extinguishing the fire, lay the foam fire extinguisher on the ground with the nozzle facing downward;

It can also be used to extinguish Class A, B and C fires, and can also be used to extinguish general live fires. a. Refers to combustible solid fires, such as wood, cotton, wool, hemp, paper, etc. b refers to liquid fires, such as gasoline, kerosene, methanol, ether, propylene and other burning fires; c refers to a fire in which combustible gases such as gas, natural gas, methane, acetylene, hydrogen, etc. are burned.

When using dry chemical fire extinguishers, you can use ordinary dry chemical fire extinguishers or ultra-fine dry chemical fire extinguishers, which are two different types. Moreover, this kind of firearm can effectively control the spread of fire and play a rapid fire extinguishing effect.

Storage Points:

1. The dry powder storage container shall comply with the provisions of the current national standard "Regulations for Safety and Technical Supervision of Pressure Vessels"; The drive gas storage cylinder and its filling coefficient shall comply with the provisions of the current national standard "Gas Cylinder Safety Supervision Regulations".

2. The dry powder storage container is set with a molded pressure or pressure level, and the loading coefficient of the dry powder fire extinguishing agent should not be greater than that, and its pressurization time should not be greater than 30s.

3. The operating pressure and rated discharge of the safety pressure relief device shall be implemented in accordance with the current national standard "General Technical Conditions for Dry Powder Fire Extinguishing Systems and Components" GB16668.

4. The dry powder storage container should meet the requirements of driving gas coefficient, dry powder storage capacity, dry powder conveying rate and pressure at the outlet of the output container valve.

Dry powder fire extinguisher can extinguish general fires, but also extinguish fires caused by oil, gas and other combustion, mainly used to extinguish oil, organic solvents and other flammable liquids, combustible gases and electrical equipment initial fire.

The method of using a dry powder fire extinguisher is to pull out the safety bolt, shake it up and down a few times, stand in the upwind position according to the wind direction, aim at the root of the fire, hold the pressure handle with one hand, and hold the nozzle with the other hand to extinguish the fire.