Powder fire extinguishers.

Powder fire extinguishers.

Powder fire extinguishers

Fire safety is unthinkable without a fire extinguisher in the room. You should know something about some of them. Powder fire extinguishersare used to extinguish all classes of fires and have a wide range of operating temperatures. Fire extinguishers of this type are used to extinguish fires of petroleum products, flammable liquids and combustible materials, as well as to extinguish fires of electrical installations under voltage up to 1000 V. The following restrictions apply: powder fire extinguishers opcannot be used to extinguish fires of alkali and alkaline earth metals and other materials that can burn without access to air. Fire extinguishing powders are finely ground mineral salts with various additives that prevent caking and clumping. The base for fire extinguishing powders is ammonium phosphate salts (mono-, diammonium phosphates, ammophos), sodium and potassium carbonate and bicarbonate, sodium and potassium chlorides, etc. The additives are organosilicon compounds, aerosil, white carbon, metal stearates, nepheline, talc, etc. The powders are stored in special packaging, protecting them from moisture. During storage, the powders are chemically inactive and do not have an abrasive effect.

Types of powder fire extinguishers

• Uploads

  Types of powder fire extinguishers — pressurized — are charged with extinguishing powder and inert gas under a pressure of 16 atm, this can be nitrogen, carbon dioxide or air. These types of powder fire extinguishers extinguish class A, B, C or BC fires depending on the type of powder used. The design of this fire extinguisher includes a locking device that allows you to open and close it with a simple movement of the hand, without applying much effort. The advantage of this type of fire extinguisher is the pressure gauge installed on the head of the fire extinguisher and showing the degree of its operability.

• Gas generator

  These types of powder fire extinguishers operate on the principle of using the energy of the generated gas to aerate the emission of the extinguishing agent. They are intended for use in passenger cars. This type of fire extinguisher can also be used in domestic conditions as a primary means of extinguishing class A, B, C fires, as well as electrical installations under voltage up to 1000 V, this already depends on the brand of the extinguishing powder. Class A — extinguishing solids, B — flammable liquids or melting solids, C — flammable gases.

• Self-acting powder fire extinguishers

  Self-acting powder fire extinguishers are designed to extinguish fires of solid and liquid substances, petroleum products, electrical equipment under voltage up to 5000 V, in small warehouses, technological, utility rooms, garages, etc. without permanent presence of people in them with fire extinguishing powders of the ABC type without human intervention. If necessary, they can be used instead of or together with portable ones.
  Powder fire extinguishers op — all types — can be used for extinguishing both outdoors and indoors.

Using a powder fire extinguisher

There are several nuances that should be taken into account when using a powder fire extinguisher. When extinguishing with a powder fire extinguisher, there is no cooling effect, which can lead to re-ignition of already extinguished fuel from heated elements of building structures or equipment. Significant contamination of the protected object with powder does not allow the use of powder fire extinguishers to protect computer rooms, electronic equipment, electrical equipment with rotating elements, etc. Using a powder fire extinguisher generates the formation of a powder cloud, as a result of which high dustiness is formed and visibility is sharply reduced. Having a high dispersion, fire extinguishing powders tend to clump and cake during storage, which can lead to a loss of fire extinguishing ability. Therefore, when using powders in fire extinguishers, it is necessary to strictly adhere to the recommended storage mode.