1. cyclone, material returning riser, materials returning feeder shall be complete and not damaged, they shall be well sealed and smooth in each part; 

2.The abrasion-proof shall not be damaged and does not fall out. 

3. The air hood shall be in good condition and not damaged, the air inlet shall be smooth and the bed shall be free of sundries.  

4. The adjusting damper shall be sensitive and useful; and shall be correctly indicated. 

5. Each inflatable pipe shall be smooth, complete and not blocked.