Deaeration Process
Deaeration is the process of removal of oxygen, Carbon dioxide and other non condensable gases from boiler feed water thereby reducing the risk of corrosion in the pressure parts of the boiler.
Deaeration of two types namely Mechanical Deaeration and Chemical Deaeration.
Mechanical deaeration works on the principle of Henry’s law of physics.Removal of oxygen, carbon dioxide and other non-condensable gases from boiler feed water is vital to boiler equipment longevity as well as safety of operation.
The deaerator capacity rating shall exceed the capacity of the steam system it is servicing and have a minimum of 10 minutes storage capacity to the overflow. The deaerator shall be designed for oxygen removal to 0.005 cc/l (7 ppb) or less and carbon dioxide removal to a zero measurable level in the effluent throughout all load conditions between 0% and 100% of rated capacity.
Deaeration is the removal of dissolved or entrained gases from water to be used as boiler feed or for other processes. The gases of concern to steam plant operators are usually oxygen and carbon dioxide which are present in water due to natural cases. Oxygen and carbon dioxide present in untreated water cause corrosion of the usual boiler and steam plant materials. The rate of the corrosive action is proportional to the amount of the gas present in the feed water and is accelerated by high temperature.
Working principle of Deaerator
The primary purpose of deaeration is to remove the dissolved oxygen and carbon dioxide from water to such low levels that their corrosive potential with regard to carbon and low alloy steel is eliminated under the temperature and pressure conditions prevailing in steam generation and transport equipment. The economic value of being able to use steel, rather than higher alloy,
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