Water Quality

Water and steam circuit are taken continuously and reduced in both temperature and pressure before being sample and analyzed for parameter such as specific and cationic conductivity, pH, silica, sodium and oxygen. Everyday the chemist team analyzed sample. This job is suitable for woman cause need high accurate.

Primary target for steady state operation

1. Make up water
Specific conductivity should be less than 0.5micro.s/cm. If the reading got 0.7micro.s/cm, check the storage tank.


2. Condensate Extraction Pump.
Specific conductivity between 5 - 15micro.s/cm. This value depends on boiler pH. If boiler pH tend to decrease, ammonia injection to CEP should be add more and it becomes increasing value of Specific conductivity and pH on CEP.
Cationic conductivity should be less than 0.2micro.s/cm. If the reading is higher than 0.3micro.s/cm may indication condenser leaks. Why cationic conductivity? Specific conductivity is general reading. When we inject ammonia or hydrazine, Specific conductivity is getting high. But if we want to detect condenser leak by analyzed sea water NaCL, w should filtered water sample by anion resin. The sample is tapping at CEP outlet by anion resin which filter Mg, Ca, Na. Sea water (NaCl), Na has filtered by anion resin, and Cl is passing from anion resin. When cationic conductivity get high means sea water content on the hot-well (condenser leak).

3. De-aerator inlet
Specific conductivity between 5 - 15micro.s/cm. This value depends on boiler pH.

4. Economiser inlet
Specific conductivity between 5 - 15micro.s/cm. This value depends on boiler pH.
Cationic conductivity should be less than 0.2micro.s/cm. If the reading is higher than 0.3micro.s/cm, super-heater and re-heater spray should be out of services.
Dissolved oxygen should be less than 10 ppb. If the reading is higher than 20 ppb, hydrazine injection should be increase.

5. Boiler water
Specific conductivity between 5 - 15micro.s/cm.This value depends on boiler pH.
Cationic conductivity should be less than 1.5micro.s/cm.If the value is higher than 3micro.s/cm, do contact with chemist. pH is maintain 9.2 - 9.8 by adjusting amonia dosing.If pH less than 8.5, immediate shutdown boiler. Silica is maintain less than 200 ppb by open continuous blow down.

6. Superheated Steam
Specific conductivity between 5 - 15micro.s/cm.This value depends on boiler pH.
Cationic conductivity should be less than 0.2micro.s/cm.If the value is higher than 0.3micro.s/cm, take spray out of service. Silica and sodium are maintain less than 10 ppb by open continuous blow down.

More information
1.http://www.mckenziecorp.com/boiler_tip_10.htm