Granule Automatic Hoist is an automated device for vertically or inclined conveying granular materials. Common types include bucket elevators, Z-type hoists and screw hoists, widely used in the food, chemical, grain and plastics industries.

So, what are the common defects of granule automatic hoists? Have you ever learned about them?
1. Material Blockage at the Base
Symptom: material accumulates and jams at the bottom, motor overload alarm and shutdown
Causes: excessive feed flow; large impurities entering; serious material return from buckets; granules damp and caked; insufficient tension causing slippage, with material piling up at the base
Impact: motor burnout, damaged buckets
2. Belt Deviation / Chain Derailment
Symptom: the belt rubs the casing on one side, causing wear and tearing; the chain jumps teeth or derails
Causes: head and tail pulleys not parallel; inconsistent tension on both sides; off-center load on buckets; single-side material feeding
Impact: belt scraping and tearing, buckets colliding with the casing and deforming
3. Loose, Falling or Cracked Buckets
Symptom: buckets wobble or drop during operation; bucket corners wear through, and granules spill into the casing
Causes: fixing bolts loosening from long-term vibration; granules wearing the buckets; impact with hard objects; bolt fatigue fracture
4. Large Material Return, Low Conveying Efficiency
Symptom: incomplete discharging at the top, granules falling back inside the casing, recirculating and increasing wear
Causes: inappropriate bucket speed; wrong bucket shape selection; excessive clearance at the discharge baffle
5. Traction Component Slipping
Symptom: the motor runs but the belt/chain does not move; at the same material level, feeding becomes slower
Causes: insufficient belt tension; worn head pulley surface; increased resistance from material accumulation at the base; overload feeding
6. Abnormal Noise and Strong Vibration
Causes: worn bearings lacking lubrication; buckets scraping the casing; loose chain; loose anchor bolts on the frame; foreign objects stuck in buckets
7. Material Level Automatic Control Failure, Unable to Start/Stop Automatically
Symptom: does not stop when full / does not start when short of material; the level probe is covered by granule dust and triggers falsely
Causes: dust accumulation on the level sensor; loose wiring; incorrect probe installation position
8. Dust Leakage and Granule Spillage
Symptom: granules and dust leak from casing seams, inspection doors and inlet/outlet ports
Causes: aged sealing strips; inspection door not fully closed; deformed casing; broken observation window
9. Motor and Reducer Overheating
Causes: long-term overload; blockage and jamming; dust accumulation on the cooling fan; aged lubricating grease