Process principle:
The hardness of calcium and magnesium in boiler feed water will undergo chemical reaction in high temperature environment, or concentrate and crystallize, resulting in insoluble scale, which is firmly attached to the heating surface of the boiler. This scale is a poor conductor of heat and will hinder heat conduction. Seriously Boiler tube burst accident may occur, in addition, it will induce and aggravate the chemical corrosion of the metal under the scale, and the harm is quite serious.
Although the boiler condensate and feed water have undergone strict softening and desalination treatment, there is still a small amount of calcium and magnesium hardness entering the boiler water. If this part of hardness is not treated, scaling will also threaten the safe operation of the boiler. At present, Adding phosphate to boiler water is the most suitable treatment method. The reaction is as follows:
10Ca₂++6PO₄₃-+2OH- Ca₁₀(OH)₂(PO₄)₆(basic calcium phosphate)
basic calcium phosphate is a kind of soft water slag, easy to be removed with the boiler blowdown, and will not adhere to the boiler and become scale.
Process overview:
The device mainly includes four parts: the liquid medicine dissolving system, the metering and dosing system, the safety system and the control system.
The solid phosphate is added to the dissolving tank, and then demineralized water or condensed water is added in proportion to stir and dissolve, and then added to the boiler drum by the metering system. The dosing control can be done manually, or it can be controlled automatically according to the control signal output by the upper system.
Scope of application: High pressure and higher parameter steam drum boiler boiler water treatment