Low-pressure centrifugal fan with long service life

The utility model discloses a long-life low-pressure centrifugal fan, which comprises a fan shell and a protection part, a fan blade part is arranged in the fan shell, the protection part comprises a containing ring, a cover plate and a connecting pipe, a through hole is formed in the inner wall of the circumference of the containing ring, the connecting pipe is welded on the outer wall of one side of the containing ring, and the cover plate is arranged in the through hole. The cover plate is connected to the top of the connecting pipe through threads, and a filter screen is embedded in the outer wall of the circumference of the containing ring. A drying agent can be stored through the containing ring, contact between water vapor and the drying agent can be achieved through the through holes, and therefore the drying agent can be used for adsorbing the water vapor around the fan blade part, corrosion of the water vapor to the fan blade part is reduced, the service life of the fan blade part is prolonged, and