METHOD OF INHIBITING CORROSION AND DEPOSITS IN WATER-ROTATION SYSTEMS Russian patent published in 1999 - IPC

FIELD: water treatment and corrosion protection. SUBSTANCE: method involves using composition of inhibitors including sodium tripolyphosphate, hydroxyethylidenediphosphonic acid, zinc sulfate, and polyethylene glycol 300. Method is performed in three steps. To additional feed water are added, in mg/l, in the first step (one day duration): tripolyphosphate (as P₂O₅) 90-100, zinc sulfate (as (Zn²⁺)) 0.9- 12, hydroxyethylidenediphosphonic acid 0.4-0.5, polyethylene glycol 1.3-1.7; in the second step (16 days duration): zinc sulfate 0.15-0.2, hydroxyethylidenediphosphonic acid 0.07-0.1; and in the third step (on the 18th day): tripolyphosphate 25-30, zinc sulfate 0.15-0.2, hydroxyethylidenediphosphonic acid 0.07-0.1, and polyethylene glycol 1.2-1.7. EFFECT: enhanced high-temperature equipment protection efficiency and reduced consumption of reagents. 2 tbl, 3 ex