Troubleshooting and Repair of High-Performance Centrifugal Explosion-Proof Fans

Troubleshooting and Repair of High-Performance Centrifugal Explosion-Proof Fans

Centrifugal explosion-proof fans are essentially variable-flow, constant-pressure devices. Under certain speed conditions, the theoretical pressure-flow curve of a centrifugal explosion-proof fan must be a straight line. However, due to internal losses, the actual characteristic curve appears as shown below. The pressure generated by a centrifugal explosion-proof fan is influenced by the inlet air. Changes in temperature or density can have a significant impact. For a specific intake volume, high intake temperature (low air density) results in lower pressure. For a given pressure-flow characteristic curve, there is a corresponding power-flow characteristic curve. When a centrifugal explosion-proof fan operates at a certain speed, the power required increases as the intake temperature decreases relative to a given flow rate. Wear on the drive components of centrifugal explosion-proof fans is a common issue in such equipment, including wear at the bearing positions of exhaust fans, in the bearing chambers, and at the fan shaft bearing positions. Considering the aforementioned issues with centrifugal explosion-proof fans, traditional maintenance methods include surface treatment, thermal spraying, and swing welding, but all have specific drawbacks: they cannot completely eliminate thermal stress caused by the high temperatures of repair welding, which can easily lead to material damage, component warping, or failure; However, electroplating results in a coating that is prone to peeling. Furthermore, since both of the aforementioned methods involve repairing metal with metal, they cannot alter the “hard-on-hard” contact relationship. Under the combined forces involved, the rubber rollers will continue to wear down. In modern European and American countries, polymer composite materials are primarily used to address these issues. These materials are widely applied in centrifugal explosion-proof fans due to their comprehensive properties, including superior adhesion and excellent compressive strength, and they can be easily disassembled and processed. Not only do they eliminate welding-induced thermal stress, but there are also no restrictions on repair thickness. Furthermore, since the metal components of the centrifugal explosion-proof fan remain intact, they can absorb machine impacts and vibrations, thereby preventing further wear.