Working Principle and Common Faults of Unloader

1. Working Principle of Unloader

1. The motor drives the rotor impeller to rotate at a constant speed through the reducer. The divided cavities of the impeller separate and store materials from the silo.

2. The upper part connects to the silo feed inlet; materials fall into the impeller cavities and are rotated to the lower discharge outlet.

3. Relying on the tiny clearance between the impeller and the casing, it locks the negative pressure of the air duct and prevents air leakage and air channeling, while realizing continuous, quantitative and uniform discharging.

4. It is suitable for powder, granular and small lump materials, commonly used for discharging at dust collector hoppers, silo bottoms and the end of screw conveyors.

2. Common Faults, Causes and Phenomena

1. No discharging or low discharge volume

   Impeller material adhesion and buildup, damp and agglomerated materials, too fast or too slow rotating speed, feed inlet blockage, excessive clearance of impeller causing air leakage and channeling.
2. Equipment jamming, unable to rotate, motor overload and tripping

   Hard foreign matter falling into the casing, jamming by agglomerated materials, bearing damage and shaft seizure, impeller deformation and casing scraping, reducer failure.
3. Abnormal casing noise and severe scraping sound

   Impeller deformation, blade wear and eccentricity, installation misalignment, foreign matter stuck between impeller and casing.
4. Air leakage, air channeling and poor air-locking effect

   Widened clearance between impeller and casing due to wear, damaged end cover seal, aging flange gasket, casing deformation.
5. Dust leakage and flange ash escaping

   Damaged sealing gasket, loose bolts, aging and worn shaft end packing/sealing parts.
6. Bearing overheating, abnormal noise and oil leakage

   Insufficient bearing lubrication, deteriorated grease, shaft misalignment, aging oil seal causing oil leakage, dust entering the bearing housing.
7. Unstable and uneven discharging flow

   Unstable rotating speed, poor material fluidity, material adhesion inside impeller cavities, improper frequency conversion speed regulation parameters.

3. Simple Troubleshooting & Maintenance Points