Bucket Elevators

A bucket elevator(also known as a grain leg in agricultural applications)is a highly efficient continuous conveying machine designed exclusively for the vertical lifting of flowable bulk materials.It is one of the most widely used pieces of equipment in bulk material handling due to its ability to elevate powders,granules,and small lumps efficiently to significant heights.

Working Principle

The operation of a bucket elevator follows a simple three-stage cycle:

Loading(Scooping):Buckets attached to a rotating belt or chain pass through the material feed point at the bottom boot section.They scoop up material as they move.

Lifting:The loaded buckets are carried vertically upwards by the continuous motion of the belt/chain within a protective casing.

Unloading:As the buckets reach the top head pulley,they invert.Depending on the type,material is discharged either by centrifugal force(high-speed)or by gravity(low-speed)into a discharge chute.

Main Components

Buckets:Containers to hold the material,available in various shapes(rounded,flat,triangular)to suit different materials.

Traction Member:Either a rubber belt(for light to medium loads,high speed)or steel chain(for heavy,hot,or abrasive materials).

Head Section:Contains the drive pulley,motor,gearbox,and discharge chute.

Boot Section:Contains the tail pulley,tensioning device,and material inlet.

Casing:The enclosed metal housing that protects the mechanism,contains dust,and ensures safety.

Drive&Tension Systems:Provide power and maintain proper tension on the belt/chain.

Main Types

Centrifugal Discharge Elevators

Speed:High(0.5–1.0 m/s)

Use:Ideal for free-flowing,dry materials(grain,sand,cement).

Principle:Uses centrifugal force to throw material out.Buckets are spaced apart.

Continuous Discharge Elevators

Speed:Low(0.25–0.5 m/s)

Use:For fragile,friable,or sluggish materials(fertilizer,light aggregates).

Principle:Buckets are closely spaced;material slides out gently from the front of each bucket.

Positive Discharge Elevators

Speed:Very Low

Use:For sticky,moist,or hard-to-handle materials.

Principle:Buckets are positively rotated to ensure complete emptying.