METHOD OF CLEANING SURFACES FROM DIRT Russian patent published in 2003 - IPC

FIELD: leaning surfaces from scale, salts, salts of heavy metals, aluminum and iron compounds. SUBSTANCE: proposed method may be used for cleaning filters, boilers, domestic heaters and utensils. Proposed method includes treatment of surfaces with washing solution during heating; washing solution contains acetic acid, hydroxides of aluminum or iron or their mixture. Aluminum hydroxide is introduced in the amount of 100 to 660 ml at pH of 6.5, glacial acetic acid in the amount of from 10 to 45 ml and water, up to 1 l. Washing solution shall have pH more than 3 at introduction of iron hydroxide or mixture of aluminum and iron hydroxides more than 6.Minimum temperature of heating is 75 C. Treatment at boiling is performed at removal of solid foam formed during dissolving of scale. EFFECT: enhanced efficiency; avoidance of acid corrosion. 7 cl, 1 dwg, 24 ex