Mechanism (principle) and function of scale inhibitor

The chemical name of the scale inhibitor is n, N, N’, n’- ethylenediamine tetramethylene phosphonic acid hydrate, so it can be seen that it contains effective scale inhibiting components. Based on the principle of reaction between dirt and acid root, it can remove dirt and increase brightness at the same time to ensure the effect of scale inhibition; In terms of the mechanism of scale inhibitor, the role of scale inhibitor includes chelation and solubilization, coagulation and dispersion, electrostatic repulsion and crystal distortion. Dispersion is the remedial measure of chelation, and lattice distortion is the remedial measure of dispersion.

Chelate solubilization

After the reverse osmosis scale inhibitor is dissolved in water, the ionization phenomenon will occur, so that a negatively charged molecular chain will be generated. This molecular chain can reduce the calcium ion in the water to form a chelate or complex that can be dissolved in the water, so as to dissolve the scale and remove the scale.

Coagulation and dispersion

The anions generated during the dissociation of scale inhibitor in water collide with calcium carbonate microcrystals, resulting in physical and chemical adsorption and condensation, which makes the surface of microcrystal electric double layer negatively charged. When the adsorbed products contact with other scale inhibitor molecules, the adsorbed crystals transfer and the grains are evenly dispersed. The result of dispersion is to prevent the mutual contact and condensation between the scale forming particles, so as to prevent the growth of scale.

Electrostatic repulsion

Corrosion and scale inhibitors occupy a certain position on microcrystals through their molecular functional groups, which destroys the growth, slows down the growth rate of crystals, increases the repulsive force between crystals, and prevents them from polymerization, thus playing the role of corrosion and scale inhibition.

Crystal distortion

When the hardness and alkalinity of the circulating water treatment system are high, and the scale inhibitor input is not enough to completely prevent them from precipitation, they are precipitated. If there is no dispersed scale inhibitor, the growth of scale will obey the general law of crystal growth, and the formed scale will firmly adhere to the surface of heat exchanger; If there is enough circulating water dispersed scale inhibitor, it will be adsorbed and surrounded, which prevents the scaling particles from arranging on its regular lattice lattice, so that the generated dirt is soft and easy to be washed away by the water flow, and finally the scale inhibition effect is achieved.