How to Resolve Sticking Issues with the Moving Blades of Small High-Temperature Centrifugal Fans

How to Resolve Sticking Issues with the Moving Blades of Small High-Temperature Centrifugal Fans

Under normal circumstances, the use of small high-temperature centrifugal fans must meet the requirements of the application. Even if the on-site conditions do not meet these requirements, the machine itself can be adjusted to meet them. The rotation of the blades in a small high-temperature centrifugal fan directly affects the fan’s performance; however, if the moving blades do not rotate, it will inevitably affect the fan’s operation. The adjustment of the blades in a small high-temperature centrifugal fan is achieved by a speed-changing mechanism that drives a sliding valve, thereby altering the oil pressure differential on both sides of the hydraulic cylinder. It may be difficult or impossible to adjust the movement of the blades in a small high-temperature centrifugal fan. Failures in the hydraulic system and damage to the internal adjustment mechanism of the hub can cause issues. However, in practice, there are often other reasons. A certain clearance is maintained between the blades and the hub to adjust the angle of the rotor blades; however, incomplete combustion can cause carbon deposits and dust to clog this clearance, thereby obstructing the adjustment of the rotor blades. This is widely used in boilers that burn oil and in boilers designed to remove water film dust. The primary countermeasures are as follows. 1.1. Install a steam cleaning line at the impeller inlet to clean the impeller when the centrifugal fan is stopped, maintaining impeller cleanliness. Steam pressure ≤ 0.2 MPa, temperature ≤ 200°C. 2.2. Ensure complete combustion of fuel or coal to reduce soot. Appropriately increase the temperature of exhaust and intake air to prevent sulfur in the flue gas from condensing in the air preheater. 3.3. Adjust the opening of the movable blades within the specified timeframe to prevent prolonged expansion or contraction at the opening. After shutting down the small high-temperature centrifugal fan, the movable blades must be moved intermittently within a range of 0–55°. The operation of small high-temperature centrifugal fans requires regular inspections, particularly of internal sensitive components, to ensure proper performance. If there are issues with the movable blades, first consider adjusting the oil pressure. If adjustment is not possible, check the internal system for malfunctions.