Replacement Method for Fire Smoke Exhaust Box Fan Components

Replacement Method for Fire Smoke Exhaust Box Fan ComponentsFire smoke exhaust box fans are widely used and primarily consist of an impeller, outer cover, coupling, shaft, and other components. Among these, the impeller serves as the primary working component that generates air pressure and transmits energy. The casing primarily channels incoming air and exhaust gases, converting part of the gas's kinetic energy into pressure energy. The coupling connects the motor and fan to transmit torque. The shaft is mounted to secure the impeller, which connects to the motor via the coupling. After the fire smoke exhaust box fan stops, engage the main brake to shut down the fan. Notify relevant personnel to remove electrical components connected to the centrifugal fan (such as temperature and vibration sensors) and label them for proper storage. Remove the coupling. Disassemble the locating pins from the fan housing flange and remove the bolts. Remove the connecting bolts between the bearing housing and the upper section of the fire smoke exhaust box fan. Use a crane to lift the upper section. Then, remove the upper sections of the front and rear bearing housings for lifting. During lifting, maintain horizontal and vertical alignment as much as possible. Lifting at an angle may damage internal components. Inspect each component for damage and verify that the dimensions and clearances at the coupling end are not misaligned. Document any issues found. Mark the position of the entire rotor assembly within the fire smoke exhaust box fan, including all components of the front and rear bearing housings. Remove the rotor. After lifting the rotor, clean the bearing seats, inspect for wear, and measure both upper and lower bearing seats to confirm they remain within tolerance limits. Replace if significant damage is present or tolerances are exceeded. For example, in the case of fire exhaust box-type fan bearing components, these include bearings, locating rings, seal bodies, seal rings, end covers, etc. Replace any problematic parts. After replacement, reassemble according to pre-disassembly markings. Verify correct sequence and positioning before assembling the entire unit. Fill the bearings with lubricating oil. Confirm the internal cavities of the upper and lower housings are clean and free of debris. Ensure all stage seals are installed in designated positions and that upper/lower housing markings align. After installing the lower bearing housing onto the lower casing, move it onto the rotor. Add oil to the oil chamber, install the upper half of the bearing housing, secure it with locating pins, and install the front and rear end covers. Manually rotate the unit to check for smoothness and scratches. If no issues are found, install the upper casing, secure the locating pins and bolts, install the coupling, and begin trial operation.