What is the function of trisodium phosphate? Conditions for functioning
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Why is chemical dosing added to each drum in the catalytic unit? What effect is to be achieved? What metrics need to be met? Why are the operating conditions applied to the drum?
Trisodium phosphate prevents scaling. Since the boiler water is at boiling conditions and has a pH value of 9–10.5, calcium ions and phosphate ions in the water react to form basic calcium phosphate, which is a soft type of sludge that can be easily removed through the boiler’s blowdown process without sticking to the inside of the boiler and forming secondary scale. As basic calcium phosphate is an insoluble compound with a low solubility product, maintaining an appropriate amount of excess phosphate ions in the water ensures that the concentration of calcium ions remains very low. This prevents the formation of calcium sulfate and calcium silicate, thus avoiding scale formation.
Is good boiling only possible in a drum? Why not add it to the deoxygenated water in the deaerator?
In simple terms, the effect of acting directly on the boiler water is better than that of adding it to the deaerator!