How can the problem of severe bullet wear be solved?

Shot wear is a common issue in shot blasting operations, primarily linked to the shot material itself, usage frequency, and the wear of internal machine components. Addressing excessive shot wear requires both effective shot management and proper equipment maintenance.

**Shot Management and Replacement**

**Regular sorting and cleaning:** After every period of downtime, the shot should be sorted; broken, rusted, or severely worn shot (typically defined by a diameter reduction of more than one-third or visible cracks) must be removed immediately to prevent it from impairing cleaning efficiency or accelerating the wear of other components.

**Replenishment with new shot:** If the total volume of shot is insufficient or the average particle size has decreased significantly, new shot with appropriate specifications should be added immediately to maintain blasting efficiency.

**Selection of highly wear-resistant shot:** Priority should be given to shot materials with superior wear resistance—such as high-chromium cast iron—to extend service life and reduce replacement frequency.

**Inspection and Replacement of Key Equipment Components**

Accelerated shot wear is often linked to the wear of vulnerable internal parts within the shot blasting machine. The following components require regular inspection and replacement:

**Blades:** Blades must be replaced when the wear depth exceeds half their original thickness or when cracks or grooves appear. It is recommended to replace the entire set (8 blades) simultaneously to ensure dynamic balance and prevent increased vibration.

**Control cage and shot distributor:** Control cages should be replaced immediately when the internal diameter wears by approximately 10 mm, or when wear on the shot distributor's outer diameter exceeds 15 mm. Wear increases the shot dispersion angle, thereby exacerbating wear caused by collisions between the protective plate and the shot.

**Protective plates (end plates, side plates, top plates):** Protective plates must be replaced when their thickness is reduced to less than one-fifth of the original, or when distinct grooves or cracks appear. Worn protective plates alter the shot trajectory, increasing energy losses from inter-particle collisions. Impeller: Wear, deformation, or irregularities at the interface between the impeller disc and the separator disc can cause severe vibration, leading to unstable shot discharge and accelerated wear. It is recommended to use an impeller made of high-chromium steel treated via 42CrMoV vacuum quenching, which ensures superior wear resistance.