Condensate polisher is equipment used in steam power plant (PLTU) systems or other industrial installations that use a closed steam cycle, to purify condensate (water from steam condensation). The aim is to keep the boiler feed water quality very pure and prevent corrosion or deposition in the system.

Here is a more detailed explanation:

Main functions

Condensate polisher functions to:

1. Removing dissolved impurities such as sodium ions (Na⁺), chlorides (Cl-), silica (SiO₂), and organic substances.

2. Captures solid particles or rust that may be carried over from the steam pipes and condenser.

3. Keeping the conductivity of the condensate water very low (typically <0.1 µS/cm).

In this way, the quality of boiler feed water remains high and the life of equipment (such as pipes, turbines, and boilers) can be longer.

Working principle

Condensate polisher works based on ion exchange. It usually consists of cation and anion resins:

• Cation resins exchange positive ions such as Na⁺, Ca²⁺, Mg²⁺ with H⁺.

• Anion resins exchange negative ions such as Cl-, SO₄²-, SiO₃²- with OH-.
  The combined H⁺ and OH- then form H₂O (pure water).

Location in the system

The condensate polisher is placed after the condenser and before the deaerator in the condensate flow path. So the sequence is usually:

Turbine → Condenser → Condensate Polisher → Deaerator → Boiler Feed Pump → Boiler

Types of condensate polisher

1. Deep bed type - uses thick resin layer (usually 0.8-1 m), has high capacity, suitable for large systems.

2. Precoat type - fine resin is coated on the filter, often used in power plants because it is easy to replace and regenerates quickly.

Advantages

• Lower corrosion rate.

• Reduces boiler maintenance downtime.

• Improves plant efficiency and reliability.