Aim: To study the construction and working of various boiler mountings and accessories.
Theory: A boiler is defined as a closed vessel in which steam is produced from water by combustion of fuel. Also defined as “A combination of apparatus for producing, furnishing, or recovering heat together with the apparatus for transporting the heat so made available to the fluid being heated and vaporized.”
Classification of Boilers :
The boilers may be classified according to following criteria:
According to relative position of water and hot gases.
(a) Water tube boiler: A boiler in which the water flows through the tubes which are surrounded by hot combustion gases i.e. Babcock and Wilcox, Stirling, Benson boilers etc.
(b) Fire tube boiler: The hot combustion gases pass through the boiler tubes, which are surrounded by water i.e. Lancashire, Cochran, Locomotive boilers etc.
According to water circulation arrangement
(a) Natural circulation: Water circulates in the boiler due to density difference of hot and cold water e.g., Babcock and Wilcox boiler, Lancashire boiler, Locomotive boiler etc.
(b) Forced circulation: A water pump forces the water along its path, therefore, the steam generation rate increases e.g.. Benson, La Mont, Velox boilers etc.
According to position of furnaces:
(a) Internally fired: The furnace is located inside the shell e.g., Cochran, Lancashire boilers etc.
(b) Externally fired: The furnace is located outside the boiler shell i.e. Babcock and
Wilcox, Stirling boilers etc.
According to the use: Stationary, Portable, Locomotive or marine boiler.
According to position of the boilers: horizontal, inclined or vertical boilers.
The boiler mountings are the part of the boiler and are required for proper functioning. In accordance with the Indian Boiler regulations, of the boiler mountings is essential fitting for safe working of a boiler. Some of the