The construction of centrifugal fans can be classified in the following ways: 1. By the outlet angle of the impeller blades (the most core classification): - Forward-curved fan: The blades curve forward, with an outlet angle greater than 90 degrees. It has high wind pressure, a compact structure, but relatively low efficiency and high noise. It is suitable for ordinary ventilation scenarios with low noise requirements. - Backward-curved fan: The blades curve backward, with an outlet angle less than 90 degrees. It has high operating efficiency, low energy consumption, low noise, and a stable operating curve. It is the mainstream efficient choice in industrial fields. - Radial fan: The blades are in a radial straight plate shape, with an outlet angle equal to 90 degrees. It has a sturdy structure, is resistant to wear, and is easy to clean. It is often used for conveying particles, fibers, or corrosive gases.

In the realm of industrial production, maintaining a safe an efficient working environment is paramount, and factory ventilation stands out as a critical factor in achieving this goal. Among the various ventilation equipment available, centrifugal fans have emerged as the workhorse, widely adopted across diverse manufacturing sectors for their superior performance and adaptability.