ADDITIVE FOR COMBATING SCALE AND CORROSION INSIDE HEATING FURNACES OR STEAM GENERATORS AND PROCESS FOR PREPARING THE SAME

摘要

The invention relates to an additive for combating scale and corrosion inside the heating furnaces or steam generators, and to a process for producing the same. According to the invention, the additive consists of an aqueous solution comprising 25...40 g/l K + ions, 60...80 g/l NO 3 - ions, 5 ...11 g/l NH 4 + ions, NH 4 NO 3, 30...50 mg/l Cr 6+, 5...35% ethyl alcohol (or monoethyleneglycol), having a pH higher than 8 and the freezing point in the range of - 5 to - 21° C.The process for preparing the additive consists in preparing a potassium nitrate solution by mixing 4...10 parts of KNO 3 with 30...100 parts of demineralized water and a NH 4 NO 3 solution by mixing 1...4 parts of NH 4 NO 3 with 5...25 parts of demineralized water, mixing 35...110 parts of filtered KNO 3 solution and 5...30 parts of filtered NH 4 NO 3 solution, adding 5...35 parts of ethyl alcohol or monoethyleneglycol, additivating the resulting mixture with 0.6 to 1.5 parts of 1% g of aqueous (NH 4) 2 CrO 7 solution, homogenizing the resulting solution and bringing the final solution pH to values higher than or equal to 8 by means of aqueous ammonia with a concentration of 25%, the parts being expressed by weight.