Failures of Impellers in Explosion-Proof Centrifugal Fans and Their Remedial Measures

Failures of Impellers in Explosion-Proof Centrifugal Fans and Their Remedial Measures

When the impeller of an explosion-proof centrifugal fan operates for extended periods, the fan is bound to experience various forms of corrosion and wear. These issues are generally categorized as impeller corrosion, impeller wear, dust accumulation on the impeller, and exposure to high-temperature gases. Please provide a detailed explanation of the remedial measures for each type of damage. 1. Countermeasures for Corrosion in Explosion-Proof Centrifugal Fans. Corrosion in explosion-proof centrifugal fans is not limited to those transporting CO₂ and other corrosive gases; it is also very common in fans handling air containing various types of exhaust gases, and unpredictable corrosion can occur at any time. The following are the methods for addressing impeller corrosion. (1) Re-evaluate the composition of the gas medium and the materials used. (2) CO₂ gas is relatively dry, but there are few corrosion-resistant materials available; it is necessary to check for adverse operating conditions, such as the presence of water, and take appropriate measures. (3) Confirm whether the anti-corrosion coating has peeled off. Types of coating materials include metallic coatings made of thin stainless steel sheets, liquid metal spraying, and metal spraying, as well as non-metallic coatings made of paints, rubber, and plastics. If the rotor of an explosion-proof centrifugal fan becomes unbalanced and vibrates excessively due to corrosion, emergency repairs are typically performed using ordinary steel. However, since the blades of an explosion-proof centrifugal fan are rotating components, they should be replaced as soon as possible with metal materials that offer wear and corrosion resistance. 2. Please implement remedial measures. When the blades of an explosion-proof centrifugal fan are severely worn, they should be treated as vulnerable components. Examples include explosion-proof centrifugal fans used in blast furnaces at steel mills, various exhaust explosion-proof centrifugal fans at cement plants, and fans for transporting various powders. Furthermore, explosion-proof centrifugal fans are increasingly becoming types that require wear-resistant measures. To reduce wear and minimize dust generation, measures such as optimizing the impeller shape are necessary; however, reducing the impeller’s peripheral speed is an effective method. Using a 10 kW Centrifugal High-Pressure Blower Impeller Disassembly Device. When a 10 kW centrifugal high-pressure blower impeller disassembly device is available on-site, the 10 kW centrifugal high-pressure blower impeller can be disassembled immediately by applying pressure to the blower’s main shaft bearing. This method is very simple and safe. Typically, the actual operation time is only 1 to 2 hours. Disassembly Using a Hydraulic Jack Thrust Frame: If the 10 kW centrifugal high-pressure fan impeller has disassembly holes on its rim, a hydraulic jack thrust frame can be constructed to disassemble and reassemble the impeller. The specific procedure is as follows. 1. Prepare nuts that match the disassembly holes in advance. 2. Construct a mounting bracket for the hydraulic jack and attach it to the end of the nut. 3. Prepare the hydraulic jack in advance. The hydraulic jack’s specifications should be smaller than the shaft’s diameter. 4. Once the hydraulic jack is pressurized, the removable impeller will be pushed out of the shaft. 5. Apply symmetrical heat to the rim of the 10 kW centrifugal high-pressure blower. 6. Leave the upper section undisturbed for a moment, and the temperature of the 10 kW centrifugal high-pressure fan will rise. If the impeller’s temperature drops to room temperature, reheat it. A temperature difference will create a gap. 7. When repeating the above procedure, be careful not to let the propeller fall onto the fan housing. Disassembly and Assembly of the 10 kW Centrifugal High-Pressure Fan Shaft Heating Method: When there are no disassembly holes on the propeller shaft of the 10 kW centrifugal high-pressure fan, the propeller must be lowered using a hoist. During disassembly, the shaft plate heating method must be selected. This method is frequently used for the rotors of large and medium-sized 10 kW centrifugal high-pressure fan motors, which feature dual traction and dual support points.