1. Phosphate dosing device: The hardness of calcium and magnesium in boiler feedwater will undergo chemical reactions or concentrate and crystallize at high temperatures, forming insoluble scale that firmly adheres to the heating surface of the boiler. This scale is a poor conductor of heat and can hinder heat conduction. In severe cases, it may cause boiler tube bursting accidents. In addition, it can also induce and exacerbate chemical corrosion of metals under the scale, which is quite harmful. Although the boiler condensate and feedwater have undergone strict softening and desalination treatment, there is still a small amount of calcium and magnesium hardness entering the boiler water. If this hardness is not treated, scaling will also pose a threat to the safe operation of the boiler. Currently, adding phosphate to the boiler water is the most suitable treatment method. The reaction is as follows:
10Ca2++6PO4+2OH - Ca10 (OH) 2 (PO4) 6 (basic calcium phosphate)
Alkaline calcium phosphate is a soft water residue that is easily discharged with boiler discharge and will not adhere to the boiler to form scale.
2. Ammonia dosing device: The free CO2 in water can make the water acidic, and the reaction is as follows: CO2+H20 day '+C03- day. The H' in the water can cause hydrogen depolarization corrosion of metals such as carbon steel, resulting in damage to iron components. The reaction is as follows:

H '+2e - H2Fe - Fe "+2e
Especially in high-temperature and non buffering chemical desalinated water, free CO2 can greatly promote steel corrosion, so it is necessary to suppress this electrochemical reaction. Adding nitrogen to water to increase its pH value can effectively inhibit the dissociation of daily+ions Further control metal corrosion.