Introduction to induced draft fan impeller equipment and problem description
The coal mill induced draft fan is the key equipment of the gas path of the transmission pipeline, mainly including the supply fan, induced draft fan, primary fan and so on. It is the use of coal mill induced draft fan to increase the pressure and flow rate of the conveying medium to achieve the transportation of mixed gas and meet the needs of users. The chemical composition of industrial gas is more complex, corrosive impurities, dust more, due to the continuity of production, long-term continuous operation, the more industrial gas gas is transported, the more dust adheres to the impeller surface. Once the dust accumulates too much, it will lead to abnormal phenomena such as reduced conveying efficiency and serious fan vibration, and in severe cases, the bearing will be damaged due to the aggravation of fan vibration. After too much dust, it must be cleaned, and the cleaning cycle is generally short, and frequent disassembly and assembly of the fan will also have an impact on the service life of the fan.
Analysis of the causes of ash accumulation in fans and traditional solutions
The generation of ash deposits in the fan impeller and the adhesion strength of the ash deposits are affected by many factors, including the characteristics of the conveying medium, the concentration of smoke and dust, the humidity of the conveying medium, etc. When the exhaust gas flow passes through the impeller, a large amount of fine dust collides and deposits in the non-working front and trailing edge areas of the blade and the trailing edge of the blade working face near the rear disc of the impeller. It is not difficult to see that the soot concentration and humidity of the conveying medium are the key factors.
When the dust accumulation of the fan impeller reaches a certain level, the dust accumulation needs to be cleaned. The more commonly used cleaning methods include manual mechanical cleaning, high-pressure water washing, etc. Either way, most of them are temporary preservation and do not improve the generation of dust deposits.
Anti-fouling coating application properties
Analysis of the application advantages of Fushilan G1091 1092 non-stick coating material
Impeller anti-ash coating is a new maintenance mode that has been recommended in the world in recent years. The principle is to spray a layer of wear-resistant and anti-stick coating on the surface of the impeller, which can effectively delay the occurrence of dust accumulation and extend the interval between equipment maintenance by more than ten times or even longer. Fushi Blue G1091 1092 non-stick coating adopts Germany's advanced non-stick coating industrial technology. The performance is relatively reliable.
The air temperature in industrial flue gas systems is mostly between 100°C and 220°C. After the filter separates the air from the solid particles it carries, it adheres to the dust bin wall, which can lead to breakdowns and short maintenance cleaning times, sometimes unplanned downtime. When adhered to a wind turbine, the adhesion layer can cause the rotor to lose balance, which in turn can damage the bearing.
The G1091 1092 anti-stick system is a two-layer protection system based on bonded nanoparticles, including a primer with corrosion reduction properties and a substantial non-stick coating to prevent dust and other dry particulate materials from adhering to flue road management equipment and devices, as well as particulate material storage and guidance. Fushilan G1091 1092 non-stick coating is a non-stick coating with a friction effect, which can be used in low-temperature applications in industrial processes up to 250°C. The product is a two-layer FL blue polymer composite coating (primer coating and functional non-stick coating). It takes 12 to 24 hours to harden at room temperature. The non-stick coating of Fushilan G1091 1092 can improve the fluidity of the dust medium, thus preventing the adhesion of powder and dust. The tribological properties of this non-stick coating increase the frictional properties of the separator and avoid the adhesion of dusty media. There may be some slight sticking that needs to be removed by a slight cleanup (via an air sootblower). The coating also acts as a protective force against corrosion of the substrate.
Fushilan G1091 1092 non-stick coating application steps
1.First, the dynamic balance of the protective impeller is checked and the operating requirements are met.
2.The surface is sandblasted, and no dead corners can be left. The surface is clean, free of grease, oxide and dust, and any surface residue may affect the adhesion of the coating. Sandblasting standards up to SA 25 grade or ra 02~0.Level 3.
3.The application process and curing process ensure that the construction environment is free of dust. The ambient temperature of the construction > 15 60. Low humidity and good ventilation are required (to facilitate curing progress).
4.Connect the air source, and the pressure of the paint spray gun is 20~3.0 bar (psi 30 45);Airless spraying pressure 150-200 bar (psi 2000 3000).
5.Mix the primer material thoroughly with a stirrer and stir well for 5 to 10 minutes before application.
6.Adjust the spray gun. Paint spray gun nozzle 10~1.4mm, airless spray nozzle 03~0.4mmmm。Make sure the gun is atomized finely, and spraying with a larger flow rate is not helpful.
7.The thickness of the coating with G1091 primer is not less than 30 40 m, and the maximum is not more than 60 m. Please note that the thickness of the coating can be done by multiple sprays, but the total thickness cannot exceed the recommended coating thickness. If the metal surface of the fan is very rough, you can spray it a little more to flatten it. Please also pay attention to the operation during application, and in any case avoid spraying too much paint in a small area at once to avoid tearing the applied surface.
8.Allow the surface of the primer to dry for 2 hours at room temperature before applying the second coat.
9.Apply the G1092 topcoat as the same as the primer (same as above) and evenly cover the primer material. The thickness of the topcoat coating is not less than 40 80 m, and the maximum is not more than 100 m. As with primers, the coating thickness is very thin and finally completely applied.
10.After 12 hours of material, the initial cure, the thickness of the spray can be detected with a thickness gauge;Let stand for 5 working days to be fully ceramicized.
11.The equipment is dynamically balanced, and the unqualified points can be repaired with materials.
Engineer field construction application legend