Water Treatment Plant Process:
Water treatment process is very necessary in a steam power plant. In water various solid materials (silt, sand, mud etc), mineral materials (ions like Fe, Ca, K, Mg, Mn etc) and gases (CO2, CO, O2, NH3, H2 etc) are dissolved. If mineral water is used then it corroded every parts of the plant and forms a layer on glass tubes of boiler. This layer may acts as thermal insulation on the tubes.
So when heat is applied then no heat exchange takes place to water from tubes for insulation. Hence the tubes are bent at a high temperature which may blast any time. Finally it causes boiler trip as well as plant trip.
Impurities of water:
- Suspended undissolved solid substances (wooden piece, dead animal, sand, silt, dust, stone particles etc.).
- Dissolved solid and liquid substances (organic and inorganic).
- Dissolved and free gases (CO2, Fe2(SO4)3, O2, H2O etc).
- Bacterial substances
Solid impurities removed by filtering but minerals and gases are not removed. So to remove this impurities water treatment process is necessary.
- At first the raw water is mixed with Al2(SO4)3 and poly electrolyte to remove sludge rapidly.
- In sedimentation basin the sludge are clarified and separated as clean water.
- Clean water is separated in other basin and the sludge is removed from basin by a pump.
- Then the water is pumped to the Gravel filter. The “Anthracite coal” of the filter removed the solid particles like sand, silt etc.
- Finally the water passes through the scavenger, cation, anion and mixed bed filter and removed minerals and gases.