Centrifugal fan impeller anticorrosive treatment method 

 In view of the problem of impeller corrosion of centrifugal induced draft fan, the causes are analyzed and the treatment methods are given. 1 Existing problems The corrosion of mechanical equipment is the biggest problem in the production of chemical enterprises. Due to the special production medium, the equipment is often corroded by various chemical elements, and the contact is mainly hydrogen chloride gas. The corrosion of the impeller of centrifugal induced draft fan is more serious. Because the impeller of the centrifugal fan has larger contact with hydrogen chloride gas and more moisture, the impeller material is chrome-nickel, but the corrosion degree is more serious each time, and even the 3 ~ 6 mm thick chrome-nickel material blade is corroded as thin as paper. In the face of the adverse conditions of the environment and production process, we constantly explore the experience, which is summarized as follows. 2 Anticorrosion method At the beginning, 470 resin was applied to the impeller surface of the centrifugal induced draft fan, but the effect was not good from the running condition. The impeller corrosion was shown in Figure 1. 1 Impeller corrosion After a few days, the vibration value of centrifugal induced draft fan reaches the amplitude of 10 ~ 20 mm/s, which has a serious impact on production. According to the actual situation of the production site, the anti-corrosion of the centrifugal induced draft fan impeller is explored again in practice. According to the production process medium and temperature, as well as the impeller diameter and speed of the centrifugal induced draft fan, the specific anti-corrosion methods are as follows. (1) First of all, the corrosion impeller is polished and sandblasted. (2) Evenly paint 901 or 470 resin on the impeller body, which is bonded to the impeller surface and impeller blade with polyester cloth. (3) Evenly paint 901 or 470 resin on the polyester cloth again, and bond it with glass staple felt (Figure 2). The bonding surface must be smooth and even. 2 Bonding (4) Evenly brush 984 or 470 resin on the bonded felt, and talcum powder groove, above with glass cloth bonding. (5) A final coat of 984 or 470 resin is applied and talcum powder is mixed (FIG. 3). Three pairs of materials After anti-corrosion treatment of centrifugal induced draft fan according to the above methods, after 3 ~ 6 hours (according to the ambient temperature) the bonded anti-corrosion material is completely dry, the impeller rotor part is re-installed, and the induced draft fan shell is re-installed at the same time. After the re-installation is completed, the centrifugal induced draft fan is comprehensively checked and confirmed, and the advanced action balance test is divided into online test and offline test. Through online test, the speed probe and vibration probe of the dynamic balance instrument were installed and connected, as shown in Figure 4. 4 Probe Installation Start the centrifugal induced draft fan according to the usual operating frequency, and look at the vibration data tested by the dynamic balance instrument (Figure 5). 5 Test data of dynamic balance instrument Then according to the impeller diameter and steering and dynamic balance indicated by the Angle, calculate the number and position of the counterweight block, according to the usual grope diameter in 1200 mm below the impeller with counterweight block 20 ~ 30 g, diameter in 1200 ~ 1800 mm with counterweight block 60 ~ 80 g, When the diameter is above 1800 mm, add a counterweight block of 90 ~ 120 g. It is qualified until the vibration value reaches 3 ~ 5 mm/s, in which case the dynamic balancing operation is completed, and then the centrifugal induced draft fan enters the normal operation state. The production and use of centrifugal induced draft fan impeller has been greatly improved, reducing the number of maintenance and maintenance costs, the shortest can also be used 30 ~ 60d.