What is steam? Types of steam

The article describes what steam is, what kinds of it are, and how water vapor is used in industry and everyday life.

Physics

One of the basic sciences that help to know the structure of the surrounding world and some of its processes is physics. Around us every second there are many interesting reactions. To many of them we have long been accustomed to and do not pay attention to them. Moreover, in everyday life, few people think about the nature of the burning of the Sun, or the emergence of water vapor, which has a huge impact on the climate. And although the processes described above have been studied rather well, we will nevertheless consider the question of what steam is. By the way, it can form as a result not only the boiling or evaporation of water, but also other reactions of different substances, but everything in order.

Definition

A vapor is a gaseous state of a substance, provided that this phase is in equilibrium with other aggregate states of a given matter. The very process, as a result of which the vapor also appears, is usually called steam generation, and the reverse process is called condensation. So now we know what steam is. By the way, usually with the mention of the word "pairs", almost always people mean the steam that is obtained from ordinary water, although, as mentioned above, this aggregate state can take many substances.

In addition, it is common to distinguish two main types: saturated and unsaturated. But these definitions are applicable only to substances that are chemically pure. Let us analyze them in more detail.

What is unsaturated steam?

So they call him when he could not reach a balance, called dynamic, with respect to the fluid from which he was formed. Often such a definition is confused with thermodynamic, which is wrong. If we compare the pressure of an unsaturated vapor with a saturated one, it will always have a lower value.

When an unsaturated vapor appears on the surface of the liquid, the process of its formation proceeds faster and predominates over the inverse process (as we have already called, it is called condensation). And as a result, gradually the fluid becomes less and less.

Now let's consider what saturated steam is.

Saturated steam

Saturated steam is called when it was able to reach a dynamic equilibrium with the liquid from which it was obtained. To put it simply, then in this case evaporation equals condensation, and unlike the situation with unsaturated vapor, the amount of liquid can remain unchanged. Now we know what steam is and about its types.

If, for example, the vapor is compressed, which is in equilibrium with its liquid, then this balance will gradually disappear, and condensation will become stronger until the dynamic balance is restored again due to a change in the density of the gaseous substance.

Depending on the type of liquid, dynamic equilibrium with the vapor is manifested at different values of its density. This is due to the fact that all substances have a different force of intermolecular attraction.

Water vapor

And yet, most often by this word people understand exactly the gaseous state of all the familiar water. If you look into the encyclopedia, you can find the main defining characteristics of the pair: the absence of color, smell and getting it, in fact, from the water.

All of us repeatedly noticed it, whether it's boiling water for cooking or evaporation of moisture from hot asphalt after the rain. But if you think about and recall the periods of industrial and technological revolution, it becomes clear that the great value in a person's life has a pair. The physics of this phenomenon is such that the gaseous state of water occupies a volume tens of times greater than its original liquid form. This observation in its time gave impetus to the development of technology.

It all began with the first steam engines, and a little later "self-propelled" wagons, as vehicles with such motors were called. But such cars were brought to a working state for a very long time, had low speed and poor handling. Everything changed only with the invention of locomotives.

In addition, water is also a good coolant and it is used in many cooling systems, and if the circuit is not closed, the result is also steam. Nowadays it is sometimes brought to a gaseous state, but not in primitive engines, but at nuclear power stations where steam turbines of electric generators rotate.

Great value evaporated water has in the climate. Having risen to a height where the temperature is much lower, the vapor condenses and falls to the surface of the earth in the form of rains. Almost the same way, snow appears.

Well, in the end, a couple are preparing dietary and just healthy food.

Under necessary conditions, steam forms fog at the surface of the earth.

Now we know what steam is and how it happens.