What does “Do Not Come in Powder” mean? This question interests many. Seeing a strange inscription in the subway, store, shopping center, school, many people freeze in confusion. What kind of "stranger" is meant? What kind of crushed particles are strongly appealed to, and why? Or is it a mockery? Not. All is serious. Let's try to understand the semantic subtleties of special means of warning citizens.
Extinguishing agent
Indeed, tablets that no one had heard of before, and had not met, are now commonplace. They "decorate" not only the subway or shops (although they are most often installed here). They can be seen in modern equipped warehouses, schools, offices. What does “Do Not Come in Powder” mean? What are we talking about? Whom and about what, at first glance, a strange expression warns?
The answer is quite simple. People are given a signal about the upcoming release of a special powder, which will follow after the occurrence of a source of fire or smoke. Plates are mandatory installed in rooms equipped with modern fire extinguishing systems. Unlike the former, water, they respond to fire by the release of an extinguishing powder composition.
Automation in action
When a flame appears, warning boards come to life automatically. An inscription illuminated by light bulbs indicates that you have a minute to leave the dangerous room. Next, the arrival of finely dispersed substance into the room. When sprayed, it will limit the presence of combustion air.
Small particles of powder are dangerous in that if they get into the respiratory tract, they can cause choking. People are obliged to leave as quickly as possible, simultaneously warning those who do not know, bewildered or did not realize the danger.
What does “Do Not Come in Powder” mean? Such a sign is hung at the entrance to the building (or room), prohibiting a person from entering. Accordingly, another warning is set at the output. It is for those who were indoors before the fire and must escape from there. Sounds: "Powder go away." Thus, the signal is given to the person, not to the substance (as some have estimated).
Method Origin
By the way, powder fire extinguishing is not such a novelty. Its rapid development dates back to the 60s of the XX century. Then in the USSR there was a need to introduce a new method at nuclear power plants (traditional measures are ineffective for extinguishing fires of sodium coolant). In the 80s, the method was tested in fires at enterprises.
It is believed that the mechanism of extinguishing action is not fully understood. It is clear that the powder cools the foci of combustion, decomposing and evaporating, dilutes the combustible medium, inhibiting chemical reactions. Now, we hope that everyone understands what “Powder Do Not Come In” means.
And don't go in the foam!
The substance is increasingly used in fire fighting. Although he eats his own pros and cons. Where the surface of solid combustible substances is smooth, it works perfectly. Settling on the uneven burning underlying surface with voids, it cannot cope with fire. Sprayed from a fire extinguisher into a container with an ignited combustible liquid “blows out” the flame, but does not prevail over the irregularities.
Cope with the fire on cable routes (knocks tongues), but later the lines burn, despite the powder coating. Knocks the flame off the car engine. But to put out the fire in the cabin, you need to fill it with the composition.
There is also a foam for extinguishing fires and signs "Do not enter the foam", "Foam leave." There is an opinion: a short inscription “Do not enter the powder” (and analogues) in an extreme situation is perceived more easily. In fractions of a second, it is impossible to penetrate into lengthy explanations. Need to be saved.