Why can't you use sea water for braende?

Why does water put out fire?

It goes without saying that we extinguish fires with water. But why actually? Why does water put out fire?

Fire needs three elements in order to burn: First, a combustible material, such as wood. Then it needs warmth. That could be a lit match. And finally, fire needs oxygen. It takes it out of the air. If any of these elements are missing, the fire will go out.

What is the water doing now? On the one hand, it cools the fire and thus extracts the necessary heat. On the other hand, the water vapor displaces the surrounding air. The oxygen is running out. Less heat, less oxygen: the water extinguishes the fire.

But be careful! You cannot pour water on all fires. Absolutely not in the event of a fat fire, for example if oil has ignited in the pan. There would be a real fat explosion. Because just one liter of water produces 1.7 cubic meters of water vapor.

A meter high flame would throw burning oil droplets through the room. If the oil burns in the pan, simply carefully place the lid on it. As a result, the fire does not receive any more oxygen, it goes out.

What does a firefighter understand by a "dead man's warning"?

An apartment building is on fire, residents are still in the building. In order to save people, the firefighters go to the limits of what is possible - often at the risk of their lives. But what happens if a firefighter has an accident while on duty? If, for example, he was hit by falling parts of a building and passed out on the ground? Because of the smoke, visibility is zero. How do you find your colleague?

The "Dead Man Warner" should help. The firefighter carries this small technical device with him. Sometimes it is already integrated in the measuring device of the respiratory protective equipment or in handheld radios.

If the fireman does not move for a longer period of time, the "dead man warning" emits a signal tone. If it is moved again shortly afterwards, the sound switches off. If this is not the case, a very loud continuous signal is sent out. In this way, the firefighters find out that a colleague is in need and are guided to him acoustically.

Author: Birgit Amrehn

Status: 02/20/2017, 2:37 pm