The article talks about what steam is, what types 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 world and some of its processes is physics. Around us every second there are many interesting reactions. We have long been accustomed to many of them 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 occurrence of water vapor, which has a huge impact on the climate. And although the processes described above have been studied fairly well, we still consider the question of what is steam. By the way, it can form as a result of not only boiling or evaporation of water, but also of other reactions of various substances, but first things first.
Definition
Steam is the gaseous state of a substance, provided that its phase is in equilibrium with other aggregate states of the matter. The process itself, as a result of which steam appears, is commonly called vaporization, and the reverse process is called condensation. So now we know what steam is. By the way, usually when mentioning the word "steam" almost always people mean that steam that is obtained from ordinary water, although, as mentioned above, many substances can accept this state of aggregation.
In addition, it is customary to distinguish two main types: saturated and unsaturated. But these definitions apply only to substances that are chemically pure. We will analyze them in more detail.
What is unsaturated steam?
This is what they call him when he was unable to achieve an equilibrium, called dynamic, with respect to the fluid from which it was formed. Often this definition is confused with thermodynamic, which is wrong. If we compare the pressure of unsaturated steam with saturated, then it will always be of lesser importance.
When unsaturated vapor appears on the surface of a liquid, the process of its formation proceeds faster and prevails over the reverse process (as we have already said, it is called condensation). And as a result, gradually the fluid becomes less and less.
Now consider what saturated steam is.
Saturated steam
Saturated steam is called in the case when it was able to achieve dynamic equilibrium with the liquid from which it was obtained. Simply put, in this case, evaporation equals condensation, and in contrast to the situation with unsaturated steam, the amount of liquid can remain unchanged. Now we know what steam is and about its types.
For example, if you compress steam that is in equilibrium with its liquid, then this balance will gradually disappear, and condensation will become stronger until, due to a change in the density of the gaseous substance, dynamic equilibrium is restored again.
Depending on the type of liquid, dynamic equilibrium with steam is manifested at different values of its density. This is due to the fact that all substances have different strengths of intermolecular attraction.
Water vapor
And yet, most often, by this word, people understand the gaseous state of familiar water. If you look into the encyclopedia, you can find the main defining characteristics of the pair: the lack of color, odor and getting it, in fact, from the water.
We all repeatedly noticed him, whether it was boiling water for cooking or evaporation of moisture from hot asphalt after rain. But if you think about and remember the periods of the industrial and technological revolution, it becomes clear that steam is of great importance in human life. The physics of this phenomenon is such that the gaseous state of water occupies a volume ten times larger than its original liquid form. It was this observation that at one time gave impetus to the development of technology.
It all started with the first steam engines, and a little later “self-propelled” wagons, as vehicles with such engines were called. But such cars were brought to working condition for a very long time, had low speed and poor handling. Everything changed only with the invention of steam locomotives.
In addition, water is also a good coolant and is used in many cooling systems, and if their circuit is not closed, then steam also appears as a result. In our time, it is sometimes sometimes specially brought to a gaseous state, but not in primitive engines, but at nuclear power plants where turbines of electric generators rotate with steam.
Of great importance is the evaporated water in the climate. Having risen to a height where the temperature is much lower, the vapor condenses and falls to the earth's surface in the form of rains. Almost the same way snow appears.
Well, in the end, a couple cook diet and just wholesome food.
Under the necessary conditions, steam forms fog at the surface of the earth.
Now we know what steam is and what it is.