Pre-Startup Inspections of Screw Conveyor After Long-Term Shutdown

After long-time shutdown and idle storage,internal components of screw conveyor are prone to moisture corrosion,material hardening blockage,lubrication failure,shaft jamming and aging damage.Before restarting the equipment,comprehensive safety inspections must be carried out to avoid sudden operation faults such as locking,blade breakage,motor burning and mechanical damage.The detailed inspection items and operation requirements are as follows.

1.Internal Material and Blockage Inspection

Check whether there is residual accumulated material,hardened material lumps,dust deposits and foreign impurities inside the conveyor trough and screw cavity.Long-term stored materials are easy to agglomerate and harden,which will cause jamming and overload at startup.All internal sundries and hardened residues shall be cleaned completely.

2.Screw Shaft and Blade Inspection

Check the spiral shaft for bending,deformation,rust,corrosion,as well as wear,crack and fracture of spiral blades.Manually rotate the screw shaft to test flexibility.Ensure there is no jamming,locking or abnormal resistance during manual rotation.

3.Sealing Component Inspection

Inspect shaft seals,end face gaskets and trough sealing parts for aging,hardening,cracking and damage.Poor sealing after long shutdown will lead to dust leakage,material leakage and air leakage during operation.Replace aging sealing parts in time.

4.Bearing and Transmission System Inspection

Check the main shaft bearings,hanging bearings,reducer and coupling.Verify lubrication condition of bearings,whether lubricating oil is deteriorated,dried up or insufficient.Check looseness,wear and damage of transmission connection parts.Supplement or replace lubricating grease as required.

5.Motor and Electrical Circuit Inspection

Inspect motor insulation,circuit wiring,junction box and cable aging.Check whether the power supply,control switch and protection circuit are normal.Ensure no short circuit,open circuit or poor contact fault before power on.

6.Equipment Fastening Inspection

Check all fixing bolts at the base,trough body,support seat and flange connections.Long-term vibration and environmental erosion may cause bolt looseness.Tighten all loose fasteners uniformly.

7.Pipeline and Auxiliary System Inspection

Check feeding hopper,discharge port and connecting pipelines for blockage,corrosion and deformation.Ensure smooth material inlet and outlet passages.For inclined conveyors,verify stability of overall support structure.

8.No-Load Test Before Formal Operation

After completing all above inspections,carry out no-load idle running test first.Run the equipment without feeding for a period of time,observe operation stability,noise,vibration and temperature rise.Only start normal material conveying after no-load operation is normal.

References

1.GB/T 7714

Wilson J,Davis R.Pre-Commissioning Inspection of Industrial Screw Conveyors Following Extended Idle Periods[J].Journal of Conveying Machinery Engineering,2021,31(4):76-82.

2.MLA

Wilson,James,and Robert Davis."Pre-Commissioning Inspection of Industrial Screw Conveyors Following Extended Idle Periods."Journal of Conveying Machinery Engineering,vol.31,no.4,2021,pp.76-82.

3.APA

Wilson,J.,&Davis,R.(2021).Pre-commissioning inspection of industrial screw conveyors following extended idle periods.Journal of Conveying Machinery Engineering,31(4),76-82.