What is a Boiler
Boiler is an important equipment of the most industrial facilities and power plants. Boiler is a closed pressure vessel used to produce high pressure or low pressure steam or to produce hot water for industrial or domestic use. Industrial steam boilers are classified in too many ways like
According to tubing methods
there are two main types of boilers Fire tube boilers and Water tube boilers
Fire tube boilers are those boilers in which fire or flue gases are inside of the tubes and water is on shell side.Fire Tube Boilers are low capacity low pressure boilers usually used for heating, process or to produce hot water.
The arrangement in the water tube boiler water is that the water is contained inside the tubes while the hot combustion gas is flows on other side of tubes.water tubes boilers produce high pressure steam which is used for power generation purposes.water tube boilers are more efficient and less dangerous than fire tube boilers.
According to type of fuel used
Coal fired boilers, oil fired boilers, gas fired boilers, Biomass boilers, electric boilers and waste heat recovery boilers.
According to steam Pressure
Low pressure Boilers , Medium Pressure Boilers and High Pressure boilers.
According to ASME there every boiler have pressure above 15 PSI is called high pressure boiler. but generally Low pressure boilers having pressure below 300 psi (Bulk Boiling). Medium pressure Boilers having pressure range between 300 psi to 800 psi (mixed Nucleate or bulk Boiling). Boilers having Pressure above 800 psi (film Boiling) are called High pressure Boilers.
According to use of steam
Process boilers, utility boilers and marine boilers
if the steam used for process the is called process boiler. utility boilers are use to generate electricity in power plants they are usually water tube boilers.
According to use of boiler
Stationary and portable boilers, there are some boilers that are not stationary like Locomotive Boilers and marine boilers.
According to the furnace position
Externally fired boilers and internally fired boilers.
According to the axis of shell
Vertical and horizontal boilers.
According to the no of tubes in boilers
Single tube and multi tube boilers. Single tube boilers like Cornish boiler and simple vertical boiler.
According to circulation of water and steam in boilers
Natural circulation and forced circulation boilers natural circulation limit is 140 Kg/cm2 above this pressure forced circulation is adopted.
According to the name of makers company names
Some companies make boilers like Babcock and Wilcox boiler and Cochran boiler.