1. Definition

A bucket elevator is a conveying machine that uses a series of buckets rigidly attached to a traction member (belt or chain) to continuously lift powdery, granular and small-lump materials vertically (or at a steep incline) inside an enclosed casing. It is widely used in grain, cement, chemical, mining and power industries.

Typical parameters: capacity dozens–1,000+ m³/h; lifting height up to ~80 m (belt type); particle size generally ≤60–100 mm; material temperature ≤60 °C (belt) / up to ~250 °C (chain & plate chain) — typical ranges, refer to the manufacturer’s data.

2. Structure & Working Principle

Three sections from bottom to top:

1. Boot (feed & tensioning): feed inlet, boot pulley/sprocket, tensioning device;
2. Middle (casing & lifting): enclosed casing, traction member (belt/chain), buckets;
3. Head (drive & discharge): drive unit (motor + reducer), head pulley/sprocket, discharge outlet.

Working flow: Feeding → Loading → Lifting → Discharging

• Feeding: material is continuously fed into the boot through the bottom feed inlet and accumulates at the base;
• Loading: buckets scoop up material as they pass around the boot pulley through the material pile;
• Lifting: the traction member carries the loaded buckets vertically up inside the casing (empty buckets return on the other side);
• Discharging: at the head, material is thrown out by centrifugal force or slides out by gravity through the discharge outlet.

3. Classification

By traction member:

• Belt type (TD): high capacity, high lifting height, smooth operation, low noise; for powders and small granules, ≤60 °C;
• Round-link chain (TH): simple structure, wear- and impact-resistant; for lumpy, abrasive materials;
• Plate chain (NE): high capacity, resistant to high temperature and wear; for large, hot and fragile materials; often uses gravity/mixed discharge.

By discharge method:

• Centrifugal: belt speed ~1.0–2.0 m/s; for powdery, free-flowing small granules;
• Gravity: belt speed ~0.4–0.8 m/s; for lumpy, fragile, abrasive materials;
• Mixed: medium speed; combines both characteristics.

By installation: vertical (most common, smallest footprint); inclined (steep angle, for confined spaces).

4. Key Technical Parameters (typical ranges)

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5. Advantages & Limitations

Advantages: vertical lifting saves floor space; sealed casing reduces dust; high capacity and lifting height with continuous operation; simple structure, smooth running, easy to automate. Limitations: sensitive to feed uniformity (choking/back-flow risk); traction member and buckets wear relatively fast; not suitable for sticky or caking materials; maintenance requires shutdown.

Typical applications: grain & feed (cereals, soybeans, feed), cement & building materials (raw meal, clinker, mineral powder, aggregates), chemicals & fertilizers (fertilizer, soda ash, plastic pellets), mining & metallurgy (ores, coke, fly ash), power & energy (coal, ash), port bulk handling.

6. Common Faults & Maintenance