The sncr desulfurization and denitrification integrated equipment has different forces to make the dust particle movement track and the gas streamline different, so as to achieve the purpose of purification. However, if the desulfurization and denitration pump is used for a long time, the equipment will be corroded.
1. Working environment
Due to the complex working environment of the integrated desulfurization and denitrification equipment, various corrosive substances may exist in it. Especially in the process of desulfurization and purification of various flue gas dust, the sulfur dioxide gas will produce sulfuric acid under certain conditions, and sulfuric acid is very corrosive. Especially the steel desulfurization and denitrification equipment will be corrosive and produce sulfate.
2. Residual substances
Part of the particulate matter may also remain in the integrated desulfurization and denitration equipment for purification treatment, and when the desulfurization agent is discharged, it will also cause corrosion to the lining device of the spray layer.
3. Acidic substances
Acidic substances will cause serious corrosion to the lining part of the integrated desulfurization and denitrification equipment.
The main corrosion factors of the desulfurization and denitration pump in the sncr wet desulfurization and denitration system:
The internal working environment of the sncr wet desulfurization and denitrification system is very complicated: solid, liquid, gas intermixing, acid-base blending, cold and hot alternating, solid and gaseous components in the flue gas, flue gas flow rate, temperature, and the pH value of the slurry, F- There are many influencing factors such as scouring, deposition and corrosion of Cl- and particulate objects.
Generally, the exhaust gas of thermal power plants contains SO2, NOx, HCl, HF and other gases. In the absorption tower, the flue gas fully contacts the absorbent containing CaCO3, Ca(OH)2 and other substances, and the pollutants are absorbed in the slurry, thereby To achieve the separation of flue gas, the desulfurization washing liquid contains acid liquids such as H2SO4, HCl, HF and Cl-, and contains about 15% to 20% of suspended solid particles. All these washing slurry will eventually be transported through the desulfurization and denitration circulating pump through the recovery system.
Because the limestone slurry and gypsum slurry contain a large amount of F-, Cl-, SO32-, SO42-plasma, and the recycling of washing water in the desulfurization system, these ions are gradually enriched in the slurry, causing serious corrosion and wear on metal parts. Especially Cl-, it is the main cause of metal pitting corrosion, crevice corrosion, stress corrosion, and selective corrosion. It accelerates the corrosion damage of metal parts in the desulfurization sewage pump.
