Powder extinguishers are used to extinguish liquid, solid and gaseous substances. This is a fairly universal means of preventing fire, which are used in any class of fire. At the same time, powder extinguishers perfectly neutralize the ignition of electrical installations up to 1000 volts.
This
type of fire extinguisher is not used for extinguishing
alkali metals and other components, the combustion of which can take place without oxygen. Powder fire extinguishers are divided into injection and gas-generating ones.
Gas generating analogs are powered by energy that is produced by gas. that, in turn, aerates the release of powder. To start the system, just press the lever and lock it for five seconds. After that, pressure is created inside the fire extinguisher, with the help of which the powder is ejected.
Injection extinguishers operate on compression energy. Such devices are charged with inert gas and powder. In this case, the emission occurs with a pressure of 16 atmospheres. The injection analogues are equipped with a locking device, so they can be freely opened and closed.
Powder type fire extinguishers are supplied with a pressure gauge that is mounted on top of the housing. Thus, the user is always aware of the health of the device. This is a huge advantage over gas generating analogues.
The device of a powder fire extinguisher of different models is not much different. As a rule, marking is made with the letters "OP", followed by numbers. These figures determine the main technical characteristics.
Today, fire extinguishers weighing from 1.6 to 122 kg are available. Their design is designed for a specific volume, so each model is assigned an individual fire extinguishing ability. Characteristics of fire extinguishers provide for different operating times. The minimum extinguishing time is 5 seconds, the maximum is 30 seconds.
As already mentioned, powder fire extinguishers are divided into a specific extinguishing ability. For precise orientation, special numbers were invented:
Marking with the letter "B" means the volume of gasoline that can be extinguished with one fire extinguisher:
10B - means that the volume of the powder of the fire extinguisher is enough to extinguish 10 liters of gasoline, a layer of which is up to 3 cm;
13B - 13 liters;
34B - 34 liters and so on.
The main features of this type of fire extinguisher are the following factors:
- there is no cooling effect, which often leads to repeated ignition;
- the powder strongly pollutes the area of the fire; therefore, such fire extinguishers are not used to extinguish electronic equipment and collector-type electric machines;
- excessive dust is formed, therefore, visibility is significantly reduced if the fire is extinguished in a small room. This complicates the process of neutralizing the source of ignition;
- the need to strictly comply with the manufacturer’s recommendations on the storage method, since, due to their dispersion, powder types of fire extinguishers during long-term storage are prone to caking and, therefore, loss of fire extinguishing ability.
Thus, powder-charged fire extinguishers must be constantly monitored for the functioning of mechanisms. At the same time, old ones are periodically replaced with new ones.