Research Status of Scale Inhibitor at Home and Abroad

In industrial production, a large amount of industrial cooling water is used. A variety of salts is dissolved in water, such as bicarbonate, carbonate, sulfate, chloride, etc.. Dissolved bicarbonate such as Ca(HCO3)2, Mg(HCO3)2 is the most unstable. The surface of Heat transfer is easy to decompose to produce insoluble carbonate. With the temperature rising, its solubility in water will reduce the crystallization, deposition in the heat transfer surface and form the scale. The formation of scale will seriously affect the endotherm of circulating condensate. The scale also will affect the heat exchange of the system and cause energy waste. And may even cause local overheating and cause boiler explosion. So the water scale is very necessary. In recent years, the continuous development of the copolymer has the following characteristics.

1) Do not contain binary copolymer of the strong acid group. Such as (MA/AA), which is superior to homo polymer polyacrylic acid and hydrolyzed maleic acid. In addition to inhibition of calcium carbonate scale, there are excellent ability to inhibit calcium phosphate scale.

2) Dual or multiple copolymer containing acid groups. Such as AA/AMPS. It can inhibit calcium phosphate, calcium phosphonate scale. It have a stable effect of zinc ions. And has dispersion effect on the iron oxide and slime.

3) Containing phosphonic dual or multiple copolymer. Such as PCA. Its features not only scale function, but also has a certain role in corrosion.

4) Environmentally friendly. Such as PASP and PESA. The performance of PESA is better than PASP. Its feature is non-toxic, resistant to chlorine and high temperature. It also has excellent resistance performance of calcium carbonate. And it has the ability of corrosion when complex with zinc. Now it has been used in water systems widely.