Steam is popular medium of thermal energy transfer, It is widely used for process heating and generation of power though steam turbines. Steam is also used for various other application. In this article we will discuss about typical application of steam, For understanding steam and its importance industries click here
Process heating : The most common use of steam for any process industry is process heating. Steam is cheaper, safer and easy to handle fluid. The use of steam at process should be at low pressure so that latent heat can be effectively used. Use of higher pressure steam for process heating can lead to loss of energy though high temperature condensate and flash steam. Generally Shell and tube heat exchanger or PHE is used for process heating , Steam trap is used to drain out condensate after heating.
Steam Drive : Steam is used as driving force from early days of industrialization, Steam engines were used for running Rail, ship and industries. Steam is used as driving force for operation of steam turbine to generate power in power plants. For improving efficiency of steam turbines pressure and temperature of steam is elevated to higher levels. Steam is in superheated condition before inlet of steam turbine. Steam drive is also used to run compressor, pumps, Fans etc.
Steam as motive fluid / Vacuum generation: Steam is commonly used in steam ejectors for creating vacuum. It is most popular in process industry due to its reliability and ability to create higher vacuum levels. Steam ejectors are stationary equipment therefore maintenance requirement is very low. The construction of steam ejectors are simple and is shown in fig below, High pressure motive steam enters the jet ejector through the inlet nozzle and is then diffused. This creates a low pressure zone to fulfil vacuum requirement.
Steam Atomization : Various liquid fuel like Furnace oil, LSHS, LDO needs to be atomized at burner before combustion. Steam atomization is the process of mechanically separating fluid into small particles for better combustion with the use of steam. Steam is injected into the fuel in order to maximize combustion efficiency and minimize formation of soot due to unburnt carbon.
Steam Moisturizing : Steam is also used widely for adding moisture in the process. Steam is injected into the process where it adds moisture and heat to the product.
Humidification: Humidification is the process of adding water into the air, In cold seasons or in air conditioned spaces where humidity needs to be added in the air steam is used. Steam adds both heat and humidity in the space.
Steam for cleaning : Steam is also effectively used for cleaning heat exchanger tubes and process equipment’s. Steam operated soot blowers are used in flue gas path of boiler to prevent fouling in the tube surfaces. Steam is also used for online cleaning of heat exchangers to remove surface deposits.