How does an industrial boiler work?
What is an industrial boiler
A boiler or steam generator is a device used to create steam by applying heat energy to water. Although the definitions are somewhat flexible, it can be said that older steam generators were commonly termed boilers and worked at low to medium pressure (1–300 psi or 6.895 – 2,068.427 kPa) but, at pressures above this, it is more usual to speak of a steam generator.
A boiler or steam generator is used wherever a source of steam is required. The form and size depends on the application: mobile steam engines such as steam locomotives, portable engines and steam-powered road vehicles typically use a smaller boiler that forms an integral part of the vehicle; stationary steam engines, industrial installations and power stations will usually have a larger separate steam generating facility connected to the point-of-use by piping. A notable exception is the steam-powered fireless locomotive, where separately-generated steam is transferred to a receiver (tank) on the locomotive. An industrial boiler, originally used for supplying steam to a stationary steam engine.
The work process of a industrial boiler
An industrial boiler is water containing vessel which transfers heat from a fuel source (oil, gas, coal) into steam which is piped to a point where it can be used to run production equipment, to sterilize, provide heat, to steam-clean, etc. Industrial boilers are powered by oil, coal and gas, which turn water into steam, by heating the water source. The steam is used to power equipments, for cleaning as well as providing heat for other functions, and afterwards the steam is returned to the vessel.
The two main types of industrial boilers
Fire tube boiler - the fire or hot gases are directed through the inside of tubes within the boiler shell, which are surrounded by water. The tubes are arranged in banks so that the gases can be passed through the boiler up to 4 times before passing out the stack. This system exposes the maximum heat transfer surface to the water. Fire tube boilers are also known as shell boilers and can produce up to approximately 750 hp or 25,000 lbs of steam per hour. 80% of boilers in use are of this configuration.
A subtype of this boiler is the packaged boiler, shipped complete with fuel burning equipment, mechanical draft equipment, automatic controls and accessories and is designed to function automatically with a very minimum of attention. It is particularly important to prevent scale formation in this type of boiler.
Water tube boiler - the fire or hot gases are directed to and around the outside of tubes containing water, arranged in a vertical position. Water tube boilers are usually rectangular in shape and have two or more drums. The separation of steam and water takes place in the top drum, while the bottom drum serves as a collection point for sludge. This system is usually used when more than 750 hp or several hundred thousand lbs of steam per hour, are needed.
There are other designs with special configurations, adapting them to particular applications.
