Analysis of the performance of flue gas anti-corrosion coatings used in cement dust collection equipment

China Paint Online News Information: Cement dust collection equipment mainly includes dust collection system and fan system, we analyze these two aspects.
and corrosion analysis of dust collection systems: the main components of
cement are silicate, Fe2O3, CaO2, Ca2SO4, Al2O3 and MgO2, consisting of limestone (76.4%), loess (76.4%) 13.05%), coal (3.2%), iron powder (1.85%) and fluorite (0.5%), after calcining the mature material at about 1500 degrees C, added a moderate amount of gypsum, slag powder grinding made. Its water is alkaline, with high dispersion, adhesion, moisture absorption and corrosion and so on. Cement dust pH is about 10-12, showing a strong alkaline, so there is alkaline corrosion environment in the dust remover.Because of the high smoke humidity, dew point temperature is also higher, if the dust collector has leakage or other defects, flue gas temperature drop easy to dew, dew hazards in addition to will cause "paste bag" impact, but also on the dust collector metal parts caused by alkali corrosion. Cement plant flue gas is generally between 220 degrees C-350 degrees C (extreme operating conditions will reach more than 400 degrees C), if the dust remover steel structure does not carry out anti-corrosion, anti-oxidation protection, then the oxidation and corrosion of metal steel structure will be very serious, falling rust will not only pollute the finished product, at the same time uneven oxidation, corrosion surface will affect the normal flow of flue gas, local will cause a large amount of dust accumulation, seriously affecting the normal production of cement plant.cement plant denitrification process, most of the use of ammonia as a reducing agent, ammonia spray excessive, will directly pollute the equipment, ammonia adsorption and corrosion is very strong, attached to the flue, dust collector and other equipment is difficult to eliminate, will gradually on the equipment Caused corrosion, at the same time, ammonia easily decomposed into ammonia gas, the higher the temperature decomposition faster, ammonia gas in a humid environment can be ionized into ammonium ions and hydrogen and oxygen root ions to form electrolyte solution, promote the metal's primary battery reaction and accelerate metal corrosion; Ammonia molecules can form a concoct with many transition metal ions to make them soluble in water and peel off the oxide film that protects the metal surface. In the process of denitrification, excessive ammonia, the formation of ammonia gas, dust collector equipment, flue and other metal equipment will cause corrosion, the urgent need for anti-corrosion measures.cement plant flue gas flow rate of about 1.5m/s, dust concentration is high, flue gas on the metal steel structure of the erosion erosion is very serious, especially the kiln head flue gas particle size is larger, although the concentration is relatively low, but the abrasive is more serious.If the coating coating for dust collection equipment corrosion, wear-resistant coating, then the coating must have the following characteristics:
1. acid resistance, alkali corrosion resistance,
2. resistance to 600 degrees C high temperature (taking into account extreme operating temperature and Give a certain amount of temperature-resistant margin;
3. Paint film hardness is high, wear-resistant and impermeable;
4. Paint smooth, do not hang dust;
5. conduct static electricity, do not retain static charge caused by friction.
6. Ammonia corrosion resistance
fan system abrasion, corrosion analysis:
In order to improve the service life of the fan imperfle, extend the replacement cycle people are actively exploring the application of different surface reinforcement technology to the fan imperfle currently used in the main reinforced fan imperfle The process method has the welding method, such as manual welding wear welding rod manual carbon arc welding wear alloy powder block, ceramic block, oxyacetylene spraying, plasma spraying, etc. , these methods improve the service life of the fan imperfle to varying degrees, but there are certain disadvantages.The welding method has a high amount of hot input to the work piece, a large labor intensity and low efficiency
small pieces of ceramic produced by the
-set ceramic block method are first ground in the course of work or the ceramic bonding will fall off locally, which causes the fan leaf Severe local wear and tear occurs on the wheel, which eventually leads to overall damage,
acetylene spraying method because of the coating particles and particles bonding strength, coating and substation binding strength is low, so the use of poor performance,
plasma spray equipment investment in large coating thickness is thin, short service life.
for wear-resistant corrosion-resistant coatings for fan guide systems:
1. Acid-resistant, alkali-resistant corrosion,
2. wear-resistant and osmotic, paint film adhesion good,
3. high temperature, heat-resistant flushing,
4. seismic, can leave the blade due to wind resistance and other conditions when slight deformation does not fall off,
5. paint smooth, no dust,
6. conductive electricity, do not retain static charge due to friction.
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