When water is used in a boiler system to generate steam, it should first be deaerated to remove gasses from the water content. As water and steam pass through the boiler system, gasses in the water content release oxygen and carbon dioxide. Excess oxygen in the system can cause the boiler to oxidize and rust build-up to damage the boiler system. Released carbon dioxide dissolves back into the water content to form carbonic acid and further damage the boiler system. This kind of damage can be avoided by removing those gasses from the boiler water content.
Mechanical Deaerators Prepare the Boiler Feedwater
A spray type deaerator uses a container vessel to deaerate the water content. This container also serves as the storage tank for the boiler feedwater. The system contains a preheating area where water is prepared to be fed into the deaeration chamber. At the bottom of the container, a sparger vents low-pressure steam into the system. This low-pressure steam from the boiler rises into a spray sourced from the feedwater tank. The rising steam heats the feedwater to its saturation point in order to strip dissolved gasses from the water content. This heated feedwater flows into the deaeration section where the sparger strips the gas content from the water. Stripped gasses exit the unit through a vent at the top while the deaerated feedwater flows back into the boiler tank. From there, it is pumped into the steam generation system.
Steam Energy Systems Need High-Quality Water
The spray type deaerator is a mechanical deaerator; it is often combined with oxygen scrubbers that chemically deaerate the water content. Both systems are commonly in use in plants that use steam energy. The combined processes produce the highest quality feedwater for the boiler system and reduce the need for additional water treatment chemicals. Preheating boiler water through the deaerator prevents thermal shock to the boiler system, reducing the fatigue of ordinary usage. The absence of dissolved gases prevents corrosion from rust and carbonic acid in the system and increases the efficiency of the steam’s potential energy.