Important Terms for Steam Boilers

Steam boilers are devices that use water as a working fluid and convert it into steam at a desired pressure and temperature. Steam boilers are widely used in various industries, such as power generation, heating, locomotive, and process applications. Steam boilers have many components and parts that perform different functions and ensure the safe and efficient operation of the boiler. Some of the common terms related to steam boilers are:

• Shell: It is the main body of the boiler and consists of a cylindrical steel vessel that contains water and steam. The shell is usually made of steel plates that are welded or riveted together. The shell must be strong enough to withstand the pressure and temperature of the steam inside it.

• Setting: The setting of a steam boiler is the foundation or base that supports the boiler and its various parts. It also provides a means of enclosing the furnace and directing the hot gases to the boiler tubes. The setting can be made of brickwork, concrete, steel or a combination of these materials.

• Grate: A grate is a platform in the combustion chamber of a steam boiler on which fuel is burnt. It consists of cast iron bars that are spaced apart so that air can pass through them.

• Furnace: The furnace is an integral component of a steam boiler that generates heat and transfers it to water, resulting in steam production. It is the chamber where combustion takes place in a steam boiler, there is more to it than just being the space above the grate and below the boiler shell.

• Water space and steam space: The water space refers to the volume of the boiler shell that is occupied by the water. The water is heated by the furnace and is then converted into steam. The water space provides enough space for the water to boil, and it is designed to ensure that the water level remains constant during operation. The water space includes the area occupied by the tubes that carry water and steam throughout the boiler.

On the other hand, the steam space is the area in the boiler shell that is not occupied by water or tubes. It is the area where steam accumulates before being directed to the steam distribution system. The steam space provides adequate space for the steam to separate from the water and allows the steam to collect and be released safely and efficiently.

• Mountings: The mountings are the essential components that are installed on the boiler shell for the safe and efficient operation of the boiler.

• Accessories: Accessories in a steam boiler are additional components that are installed to improve the performance of the boiler or to provide additional features. These accessories are not necessary for the safe operation of the boiler but can be useful in certain applications.

• Refractory: It is a heat-resistant material used in boilers to line the furnace walls, floor, and other areas exposed to high temperatures. The purpose of refractory is to protect the boiler's metal components from the high heat of the combustion process, prevent damage to the boiler, and prolong its lifespan.

• Foaming: It is a condition that occurs in steam boilers when the concentration of dissolved solids in the water exceeds the capacity of the water to hold them in solution. When this happens, the water forms bubbles on the surface, which then collapse and cause turbulence in the water.

• Water level: The level at which water stands in the boiler is called water level.

• Scale: A hard deposit of mineral salts that accumulates on the inside surfaces of the boiler. The formation of scale is a result of the build-up of dissolved minerals, such as calcium and magnesium, in the boiler water.

• Blowing off: The removal of mud and other impurities of water from the lowest part of the boiler. Accomplished with the help of blow off cock or valve.

• Lagging: Insulation wrapped on the outside of the boiler shell or steam piping.