Causes of Insufficient Conveying Capacity or No Material Conveying of Screw Conveyor

Screw conveyor is widely used bulk material conveying equipment in environmental protection,metallurgy,building materials and chemical industry.The faults of no material conveying and low output capacity will directly affect the whole production process,cause material accumulation,hopper blockage and low operation efficiency.Combined with actual operation,the main causes and corresponding solutions are analyzed as follows.

Main Causes

Material arching and bridging in feeding hopper

Dry powder materials are easy to form arching,bridging and vacuum adhesion above the feeding inlet.Even if the screw shaft runs normally,materials cannot fall into the conveyor trough smoothly,resulting in no feeding or low conveying volume.

Excessively low rotating speed

The motor speed is too slow,or the reducer is faulty,resulting in insufficient rotation speed of the screw shaft.The material pushing capacity of spiral blades is weak,which leads to obviously reduced conveying capacity.

Material blocking in the conveyor trough

Wet,viscous and agglomerated materials stick to the spiral blades and inner wall of the trough.Long-term accumulated materials cause internal blockage,so the screw can only idle and cannot transport materials normally.

Improper material moisture content

Too much moisture makes materials viscous and easy to bond;excessively dry ultra-fine powder causes floating material and air cushion effect inside the pipeline,which both lead to insufficient material output.

Wear of spiral blades

Long-term operation causes serious wear,thinning and deformation of spiral blades.The material pushing and lifting capacity is weakened greatly,resulting in reduced conveying efficiency.

Too large feeding resistance and overload accumulation

Unreasonable feeding amount,excessive stacking materials and large hard impurities inside the trough increase operation resistance,limiting the material conveying space.

Backflow of internal materials

Unreasonable clearance between spiral blade and trough body causes serious material backflow.Materials circulate inside the conveyor instead of being pushed to the discharge end continuously.

Improper installation angle

Excessively large inclined conveying angle reduces effective material pushing efficiency,resulting in insufficient output capacity.

Troubleshooting Solutions

Install vibrators on the feeding hopper to eliminate material arching and bridging phenomenon.

Check motor and reducer system,adjust rotating speed to rated working parameters.

Clean internal blocked materials and hardened deposits inside the conveyor trough thoroughly.

Control moisture of conveyed materials to keep proper dryness and fluidity.

Replace severely worn spiral blades in time to restore material pushing performance.

Control uniform feeding quantity and remove hard foreign impurities inside the equipment.

Adjust assembly clearance between screw and trough to reduce material backflow.

Optimize installation inclination angle to meet reasonable conveying requirements.

References

1.GB/T 7714

Zhang L,Han Z.Fault Analysis and Treatment of Low Conveying Capacity of Screw Conveyor[J].Bulk Material Handling,2022,47(3):88-92.

2.MLA

Zhang,Lei,and Zhi Han."Fault Analysis and Treatment of Low Conveying Capacity of Screw Conveyor."Bulk Material Handling,vol.47,no.3,2022,pp.88-92.

3.APA

Zhang,L.,&Han,Z.(2022).Fault analysis and treatment of low conveying capacity of screw conveyor.Bulk Material Handling,47(3),88-92.