Condensate Polishing

As the condensate travels through the boiler / turbine / condenser system it can acquire impurities, condensate polishing is the process of removing these components.  Impurities can be divided into two groups:

• Dissolved minerals such as sodium / chloride / carbon dioxide, primarily arising from condenser leaks
• Particulate oxides from erosion and corrosion of the boiler circuit

These contaminants can cause high corrosion within the boiler, or leave deposits on turbine blades which can reduce both the efficiency of the system and the life of the components.

Deep-bed polishing removes dissolved impurities by ion exchange with a mixed bed of strong acid cation and strong base anion resin.  Water passes down through the resin beds and as the water passes, the cation resin removes the last traces of cations whilst the anion resin removes the last traces of anions.  By this process, a very low TDS condensate is achieved at the outlet.

Particulates in the circuit are typically < 10 µm and are attracted to the highly charged surface of the resin, which gives deep bed polishing vessels good particulate removal efficiency.  For high degrees of solids removal, however, mechanical filters at 1 - 5 µm nominally rated may be required.

For the highest purity of condensate, external resin regeneration is required.  This ensures minimal cross-contamination during the regeneration, and additionally allows the condensate polishing vessels to operate at high velocity that is not achievable using internally regenerated mixed beds.  This is considered mandatory for high pressure boilers. 

Key features & benefits

Our proprietary Conesep external regeneration technology offers several benefits over other, less advanced externally regenerated systems including:

• Superior resin separation efficiency
• Allows ammonium form operation
• Regeneration with sulphuric or hydrochloric acid
• Two-vessel system
• Reliable operation, with over 150 installations
• No inert resin required
• Fully automatic resin fines removal, separation and regeneration; no manual intervention required at any stage.

How we create value

• Highest quality condensate reduces corrosion and salt deposition
• Minimizes use of regenerant chemicals by tailoring the process to the client exact requirements
• Minimizes ammonia dosing if using the Conesep technology to operate beyond the ammonia breakthrough point.
• Reduced operator intervention throughout, with fully automatic plants.