Principles of Steam Boilers
- Steam boilers work on several basic principles.boilers image by JCVStock from Fotolia.com
In the past, people used steam boilers to power locomotives, horseless carriages and steamboats. Today, although more-efficient combustion engines have replaced boiler-style engines, the steam boiler remains in common use to heat homes, commercial buildings and water. Surprisingly, the steam boiler's basic design has changed little, and today's steam boilers run on the same principles as the old coal boilers that pushed steam engines in the 19th century. - In a steam boiler, ignited fuel heats the water until it comes to a boil. Although wood and coal are the traditional fuels of older steam boilers, over the past hundred years the types of fuel we use to power steam boilers have grown to include natural gas, oil, solar power and electricity. Additionally, although most of the fuels that older boilers used were ignited directly underneath the water container to boil the water, modern boilers often use superheating elements, such as those you'll find in furnaces, ovens, and even your electric range.
- One of the key principles of a steam boiler is containment. When water is heated it produces steam, which rises. If a steam boiler is open or too large, the steam will either escape or disperse and condense back into water. But by concentrating the space in which the water has to move in a containment unit, then heating the water until it boils and becomes steam, the water molecules bounce around the walls of the containment unit and become more energized. This process of containment creates the kind of forceful energy that can run a steam engine and build up enough power to push steam hundreds of feet through pipes that twist and turn throughout a house, enabling one boiler to heat several rooms at once. Steel is often used in the construction of boilers because it can withstand the huge amounts of pressure that containment creates in the boiler tank. Typically, steam boilers are insulated with a material such as fiberglass.
- Convection is the most basic scientific principle by which steam boilers work. According to the Physics Hypertextbook, "Convection is the transfer of internal energy into or out of an object by the physical movement of a surrounding fluid that transfers the internal energy along with its mass." This means that steam boilers use the steam collecting at the top of the boiler to preheat the water flowing into the boiler from the inlet tube, which ensures that no cold water enters the boiler and lowers the temperature in the containment chamber. Convection allows for a steady consistency of steam output, making the boiler efficient.
