Steam Basics: what is steam exactly?
How does it work? And why do we use it? Become a steam expert by reading up on these steam basics.
Steam is the gaseous form of water which arises from either the liquid or solid phase due to evaporation or sublimation.
How do you produce steam?
To produce steam, water (H2O) needs to pass from liquid to gaseous state. So, in other words a phase change needs to take place.
But how does that work?
As water molecules are heated, the bonds connecting these H2O molecules start to break more rapidly than they can form. When you add enough heat, some molecules will break free. It’s these free molecules that form the transparent gas known as steam.
An everyday example of steam
Sensible versus latent heat
Heating water to the boiling point is also known as sensible heating. Once it starts to vaporize with extra heat we talk about latent heating.
What is atmospheric pressure?
Atmospheric pressure is the pressure within the atmosphere of the earth.
That didn’t really help, did it? Well, the air around us has a certain mass and it presses against everything it touches. That pressure we call atmospheric pressure. Atmospheric pressure drops as the altitude increases. Imagine the air at sea level and in the Himalaya …
As the pressure decreases, the amount of oxygen available to breathe also decreases.
The impact of atmospheric pressure on the boiling point
Now, this matters because the atmospheric pressure has an impact on the boiling point. If you would boil water at a lower pressure, your boiling point will also be lower, and the other way around. If you would boil water at a higher pressure, your boiling point will also be higher. For the cooks among us, think about how you use a pressure cooker.
Steam: the first industrial revolution
Steam, and steam engines, played an important role in the industrial revolution. The steam engine was a simple device that used boiling water to create mechanical motion. It has always been used in a variety of industrial settings: from mines to mills. The introduction of steam engines allowed technology and productivity to advance. This led to the creation of better engines. Because of the invention of high-pressure engines, transport applications became possible later on. So, steam found its way to boats, railways, roads and even farms.
Steam: an essential element for many industries today
Nowadays, steam is in use in a wide variety of sectors. Think about agriculture, food & beverage, automotive, electricity generation, and other manufacturing industries. And there are so many different applications in which steam can be used which makes it hard to categorize them.
We recognize following categories of steam
- Emergency Steam
- Steam for maintenance & turnarounds
- Steam for special or planned projects
- Temporary steam
- Long term steam
- Steam for temperature
- Steam for atomization
- Steam for energy
- Steam for humidification
Wondering how we obtained these categories?
You can find more information in the steam applications section.
Different types of steam
When reading up on steam, you’ll come across different terms like saturated or superheated steam. Which indicates not all steam is the same. And depending on your project or application, the type of steam you need is different.
What is steam?
Steam is the gaseous form of water which arises from either the liquid or solid phase due to evaporation or sublimation.
How do you produce steam?
To produce steam, you need heat to initiate a phase change. The boiling point of water is 100°C (or 212°F) at atmospheric pressure. If you keep adding energy to boiling water, the temperature will not increase, unless it's contained or pressurized.
Where and how is steam used in an industrial setting?
Today, steam is often used in the manufacturing or chemical industry and in power plants. The variation of possible applications is almost endless, which makes them hard to categorize.
Which steam types exist?
Not all steam is the same: the application defines the type of steam you need.
- Generally, we make a distinction between saturated (dry) steam and unsaturated (wet) steam.
- Additionally, we also talk about superheated steam.