What do you mean, "Do not enter the powder," "Leave the powder"?

What do you mean, "Do not enter the powder"? This question interests many. Seeing a strange inscription in the metro, shop, shopping center, school, many people freeze in confusion. What kind of "stranger" is meant? To what such severed particles are resolutely appealing and why? Or is it a mockery? No. All seriously. Let's try to understand the semantic nuances of special means of warning citizens.

Fire extinguishing agent

Indeed, tablets, of which no one has heard before, and has not met them, is now a common occurrence. They "decorate" not only the subway or shops (although here they are installed most often). They can be seen in modern equipped warehouses, schools, offices. What do you mean, "Do not enter the powder"? What is it about? Who and what warns, at first glance, a strange expression?

The solution is quite simple. People are given a signal about the impending release of a special powder, which will follow after the emerged fires or smoke. Plates are mandatory installed in rooms equipped with modern fire extinguishing systems. Unlike the previous ones, water ones, they respond to the fire with the release of a fire-extinguishing powder composition.

Automation in action

When the flame appears warning boards come to life automatically. The inscription, highlighted by bulbs, signals that you have a minute to leave the dangerous room. Next, a small amount of dispersed substance will enter the room. Spraying, it will limit the presence of air supporting combustion.

Small particles of powder are dangerous because, getting into the respiratory tract, can cause choking. People are obligated to leave as quickly as possible, simultaneously warning those who do not know, were confused or did not realize the danger.

What do you mean, "Do not enter the powder"? Such a sign is hung at the entrance to the building (or room), prohibiting a person from entering. Accordingly, a different warning is set on the output. It is for those who stayed indoors before the fire and must flee from there. Sounds like, "Leave the powder." Thus, the signal is supplied to a person, not to a substance (as some have estimated).

The origin of the method

By the way, powder fire extinguishing is not such a novelty. Its rapid development dates back to the 60s of the 20th century. Then in the USSR there was a need to introduce a new method at nuclear power plants (to extinguish the ignition of sodium coolant traditional measures are ineffective). In the 1980s, the method was tested in fires in factories.

It is believed that the mechanism of the extinguishing action has not been fully investigated. It is clear that the powder cools the foci of combustion, decomposing and evaporating, dilutes the combustible environment, inhibiting chemical reactions. Now, we hope everyone understands what "Powder does not come in" means.

Do not enter the foam!

The substance is increasingly used in firefighting. Although he also has his pluses and minuses. Where the surface of solid combustible substances is smooth, it works perfectly. Settling on an uneven burning underlying surface with voids, with fire can not cope. Sprayed from a fire extinguisher in a container with a combustible combustible liquid, "blows out" the flame, but spills over the unevenness does not prevail.

With fire on the cable routes consults (knocks down languages), but later the lines are burning, despite the powder coating. Knocks the flames off the car's engine. But to put out the fire in the cabin, you need to fill it with a compound.

There is also foam for extinguishing fires and plaques "Foam do not enter", "Foam leave". There is an opinion: a short inscription "Powder does not enter" (and analogs) in an extreme situation is perceived easier. For a split second it is impossible to delve into lengthy explanations. We must save ourselves.