Pulverized fuel boiler induced draft fan is a driven fluid machine that relies on the mechanical energy input by the motor to increase the gas pressure and exhaust the gas. Induced draft fans for large-scale power station boilers are generally fixed-blade or adjustable-blade axial flow fans. The lifting force generated by the impeller rotation is used to introduce the flue gas in the boiler into the desulfurization island or chimney in the axial direction.
The normal operation of the induced draft fan can ensure the thermal circulation in the boiler and ensure the stable production and supply of electricity. However, due to the special working environment of the induced draft fan, frequent failures occur during continuous use, which seriously affects the normal operation of the power plant.
Boiler induced draft blade wear and corrosion are a common problem, so what causes this problem to occur frequently?
1. Because the blade is hollow, some dust in the air will enter the blade when the wind enters and exits, and the solid objects in the return stroke will cause friction with the blade and cause the blade to wear.
Or because the dust removal device of the equipment is not cleaned in time, the dust enters the blade, and its function is similar to that of a file, which exacerbates the wear of the blade. In the past, the blade edge will be worn until it breaks.
2. Thermal electric boiler flue gas desulfurization technology uses the flue gas to mix the dust in the flue gas and harmful gases such as sulfur dioxide and carbon monoxide into the water through the aqueous solution or water curtain to achieve the purpose of desulfurization. The induced draft fan is generally installed at the back of the desulfurization and dust removal equipment. When the induced draft fan sends air, the sulfides and carbides in the dust will corrode the blades. In addition, the sulfur dioxide gas generated by the boiler combustion will cause different degrees of corrosion to the blades.
Faced with the problems of wear and corrosion of the boiler induced draft fan, how should we solve it?
The pulverized fuel boiler induced draft fan can be coated with an anticorrosive coating, which is a highly functional two-component thermosetting polymer coating. The coating formed after curing exhibits superior corrosion resistance. The coating molecular cross-linking is mainly based on the ether bond method (COC). The ether bond is a very strong chemical bond. Compared with epoxy resins, it does not contain hydroxyl groups. Compared with vinyl esters, it has no ester bonds, so it can withstand hydrolysis. And acid attack.
Anticorrosive coatings have significant features and benefits, including:
• Strong corrosion resistance, can withstand many corrosive chemicals, including strong acids, strong bases, gases, solvents and oxidants
• Excellent abrasion resistance
• Excellent adhesion and adhesion to metal substrates, composite materials and concrete
• Excellent flexibility
• High temperature, cold and heat resistance
• Resistant to water clearing
The excellent performance of the anticorrosive coating has made it a good application in the wear and corrosion protection of boiler induced draft fans.