After long-term use, centrifugal fans often suffer from serious dust accumulation due to various environmental factors, leading to reduced efficiency of some internal components. Therefore, it is essential to master the methods of daily cleaning to maintain the fan’s operation.

1. Using High-pressure Air to Remove Dust
   High-pressure air can be used to remove dust from the blades of the centrifugal fan and prevent scaling. Since it is challenging to reduce the impact speed of the airflow on the blades and the temperature of the exhaust gas, a high-pressure blower system can be used to address the dust and scaling problem on the impeller. The principle is to use high-pressure air through nozzles to blow onto the blade surface, achieving the following effects:

   • The high-pressure air from the nozzle generates effective scouring force, which provides excellent dust removal for the centrifugal fan.
   • Before the exhaust gas contacts the fan blades, the temperature of the exhaust gas is reduced due to the mixing effect of the compressed air, which lowers the probability of dust particles adhering to the blades.

2. Manual Cleaning of Fan Blades
   To clean the dirt on the centrifugal fan blades, the fan should be stopped, and the outer casing should be opened via the inspection door located at the top of the casing. Next, a bamboo pole should be tied to a grinder, and the grinder should be turned on at a relatively slow speed to enter the fan. The cleaning should continue until the blades align with the casing and cleaning begins.

   When cleaning the blade surface, the grinder should be turned over to clean the blades in all directions (up, down, left, and right). If possible, the inside, outside, and sides of the blades should be cleaned to restore their good performance.

3. Blade Design
   The design of the centrifugal fan blades should be streamlined as much as possible to reduce the impact energy of dust particles on the blades. This can be achieved by designing the blades to be backward-curved or wing-shaped. The angle of the blades should be sufficiently tilted to avoid hard scaling at the front of the blade and should be radially large enough to prevent soft scaling on the back of the blade. The wing blades should be carefully designed to avoid material deposition inside.

4. Lowering Gas Speed at Rotor Inlet
   The gas speed at the rotor inlet should be reduced to decrease the impact speed of particles on the rotor. Generally, this can be achieved by replacing a single inlet with a dual inlet. The fan should adopt a larger diameter and lower speed to control the rotor inlet’s circumferential speed to be less than 76m/s and the inlet wind speed to be less than 38m/s.