A pickling solid corrosion inhibitor for power plant boilers

Abstract

The invention discloses a solid corrosion inhibitor for pickling a power station boiler, and belongs to the field of corrosion inhibitors. The solid corrosion inhibitor for pickling the power stationboiler comprises 12 to 15 parts of methenamine, 6 to 8 parts of ammonium thiocyanate, 0.6 to 1 parts of bromogeramine, 0.1 to 0.2 part of benzotriazole, 2 to 5 parts of stannous chloride, 2 to 5 partsof sodium thiosulfate and 1 to 3 parts of thiourea. According to the solid corrosion inhibitor disclosed by the invention, most acids, expect nitric acid, have high corrosion inhibiting efficiency onmost metals, except zinc and aluminium; moreover, various types of corrosion and potential safety hazards, such as H<+> ion corrosion, H atomic corrosion, Fe<3+> corrosion and Cu<2+> corrosion, in apickling process are taken into full consideration, so that the solid corrosion inhibitor for pickling the power station boiler has the prominent advantages of more complete corrosion inhibiting spots, higher corrosion inhibiting efficiency, and wider application range and the like.

Description

technical field [0001] The invention relates to the field of corrosion inhibitors, in particular to a solid corrosion inhibitor for pickling of power plant boilers. Background technique [0002] Pickling and descaling of power plant boilers is a necessary measure to clean the heated inner surface and prevent accidents caused by corrosion and scaling on the heating surface. It is also one of the effective measures to improve the thermal efficiency of the boiler and improve the water vapor quality of the unit. Power plant boilers are pressure vessels. The selection of corrosion inhibitors is a key part of pickling and descaling. Most pickling corrosion inhibitors are mainly to solve the H + Corrosion inhibition, H atom corrosion, Fe 3+ Corrosion, Cu 2+ Corrosion, due to the corrosion mechanism and the H in the acidic cleaning agent + Different, the impact on the total corrosion amount is small, and the harm to conventional equipment is also small, which is often not realize...

AI Technical Summary

Problems solved by technology

[0007] In acid cleaning, as long as there is rust, Fe 3+ , due to Fe 3+ Oxidation is strong, and it will aggravate the pitting corrosion on the metal surface of carbon steel when oxidizing Fe. The metal surface with pitting corrosion will form an anode of electrochemical corrosion during the operation of the equipment, and continue to accelerate the corrosion of this point, leaving the safety of equipment operation. Hidden danger

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