SCALE INHIBITION METHOD Russian patent published in 2007 - IPC C02F5/14 

FIELD: scale prevention methods.

SUBSTANCE: invention relates to methods for preventing deposits of mineral salts and can find use in prevention of scaling on surfaces boilers and equipment in heat and steam supply systems as well as in recycling water supply systems. Method comprises adding organophosphonic acids, salts thereof, or metal complexes of these acids, to water. Indicated acids or their derivatives are added in amounts meeting following scale inhibition limits relationship: ln(Cⁱ ₊C^j _-/P_o) < σ(2ab sin γ + 2 ac sin β + bc sin α)/kTn, where C₊ represents concentration of scale forming salt cation in water, mole/dm³; i number of cations in scale forming salt; C_- concentration of scale forming salt anion in water, mole/dm³; j number of anions in scale forming salt; Po product of solubility of scale forming salt; σ free energy of water/salt interface for scale forming salt, J/m³; a, b, c are lengths of ribs of the cell in crystalline lattice of scale forming salt, m; α, β, γ are angles between ribs of the cell in crystalline lattice of scale forming salt; k is Boltzmann constant, k = 1.38·10^-23 J/K; T absolute temperature, K; and n number of formula units of scale forming salt in one cell of crystal lattice.

EFFECT: reduced process risks associated with scaling of equipment surfaces.

10 cl, 2 dwg, 2 tbl