Condensate polishing is a proven method of producing high- purity water from recovered boiler condensate. The condensate can be economically returned to an ultra-pure state by simple polishing rather than using fresh make up process water.
Typically used as part of a plane’s condensate system, condensate polishing prevents contamination risks within the production cycle which could result in loss of process efficiency and possible mechanical damage to key components. The process is used to maintain a high quality of water by removing corrosion products such as iron, copper and nickel oxides as well as dissolved solids from the steam condensate, including sodium, chloride, Sulphate and silica.
The process involves ion exchange technology, using synthetic resin based systems which perform two functions:
- Filtration of the corrosion products via direct, physical Filtration, and
- Ion exchange of the dissolved solids (ions) in the porous resin media. Exchange may be for ions of sodium, hydrogen, ammonium or hydroxide, as required by the boiler chemistry.
Condensate polishing systems for the super critical boilers typically feature external regeneration. Once the service cycle has finished, the resin is transferred from the service vessels for regeneration, and transferred back once regeneration is complete. This arrangement ensures that no regeneration chemicals can enter the condensate system or the boilers. Condensate polishing systems for other applications typically feature in-situ regeneration using conventional equipment.