Emergency treatment of impact crusher rotor fracture: carbon arc gouging and welding repair after groove opening, and symmetrical welding of reinforcement plates. After treatment, it operated normally for half a year, and the output was not affected. The rotor was replaced during overhaul.

Impact crusher is an important equipment in the ore production line. As the core crushing component of the impact crusher, once the rotor breaks, it means the suspension of production. The loss caused by the shutdown is something that no one wants to see. So in this case, are there any emergency measures to solve the "urgent need"?

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The intermediate crushing of an enterprise's aggregate line uses an impact crusher for crushing operations. The equipment has been operating normally for 4 years. After routine shutdown inspection, it was found that the impact crusher rotor was cracked at one place. Emergency measures were taken to deal with it, so that production can proceed smoothly.

CI5X impact crusher

The rotor is a steel plate welded structure, made of ZG20SiMn. The rotor rib plate is cracked, and there are symmetrical cracks on both sides of the rib plate. The analysis shows that the reasons for the rotor fracture are:

(1) The thickness of the fractured rib plate is 150mm, and there are manufacturing defects inside the rib plate;

(2) There is stress concentration at one end of the rib plate at both ends of the crack;

(3) Each plate hammer is fixed by the inclined fastening plates under the three rib plates. The three fastening plates may have inconsistent bolt tightening forces, resulting in inconsistent stress on the rib plates. One of the fastening plates is subjected to excessive force, causing the rib plate to fracture.

Since there are no rotor spare parts and the planned maintenance time has not arrived, coupled with heavy production tasks, only emergency measures can be taken to deal with it:

(1) A 50mm wide and 50mm deep groove is cut on both sides of the crack with a carbon arc gouging machine, and the groove is polished with a grinder;

(2) The crack is welded with two-protection welding, and ER50-6 welding wire is selected;

(3) The same reinforcement plate is welded on both sides of the fractured rib plate and the rib plate at the symmetrical position of the rib plate. The reinforcement plate is made of Q345B and welded with two-protection welding wire ER50-6. The rotor balance problem was considered during welding. After the crack treatment, the vibration was within the normal range when the machine was turned on, and it was put into use without balancing.

It was learned that after the fracture treatment of the impact crusher rotor, the equipment was checked to be normal in the past six months, and the output was not affected. Considering the reliability of the equipment operation and the actual production situation, the rotor was replaced during the overhaul.