Bucket Elevator Basics:

Definitions & Details

Presented by:

Webster Industries 325 Hall Street

Tiffin, OH 44883

www.websterchain.com

Bucket elevators equipped with engineered steel chain are designed to lift enormous quantities of heavy materials to considerable heights in major industries, including:

Thus chain selection is key to the proper functioning of bucket

elevators.

• Cement

• Asphalt • Construction • Mining • Agriculture • Power Generation • Aggregates (limestone) • Fertilizer

Chain Selection

Chain type is broadly based on the type of bucket elevator. Most applications involve one of these main chain types:

Offset style sidebar chains have been used for years, but with chain manufacturing technology improving, offset chains are far less common for new equipment.

• Straight sidebar

• Hardened • Bushed • Rollerless

Bucket Elevator Types

Centrifugal Discharge Elevators

Centrifugal discharge elevators are designed so that the buckets are fed material from the inlet feed chute at the boot section and discharge material via centrifugal force.

This style of elevator typically operates at a much higher chain speed when compared to the other elevator styles, which usually fall in the 220-330 fpm (feet per minute) range.

Bucket Elevator Types

Centrifugal Discharge Elevators (cont’d)

The use of a single strand rollerless chain with a K-style attachment (every 12-18”) is very common in such elevators, with attachments ranging from every 2nd pitch to every 4th pitch.

Chains that have a roller in this application will become loaded with the conveyed material between the rollers and bushings.

The presence of the conveyed material along with any moisture will cause the rollers to seize onto the bushings, preventing them from turning.

Bucket Elevator Types

Continuous Bucket Elevators

Continuous bucket elevators feature buckets that are spaced

continuously (thus the name) and discharge material via

gravity.

Chain speeds in continuous style bucket elevators are

typically in the 100-150 fpm range.

The use of steel bushed rollerless chain with a K-style

attachment are very common in this application.

Bucket Elevator Types

Continuous Bucket Elevators (cont’d)

Elevators that operate on a double strand

of chain will typically use a K-style (back

hung) or A-style (back hung) attachment to

the bucket.

Typically, buckets are spaced every

2nd pitch on 4”-6” pitch chains depending

on bucket size.

Bucket Elevator Types

Super Capacity Elevators

Super capacity elevators are a special

kind of continuous bucket

elevator designed for higher capacity

requirements.

Extra long buckets spaced continuously on

the chain are end-hung between 2 strands

of chain.

Bucket Elevator Types

Super Capacity Elevators (cont’d)

Typical chain speeds are in the range of 120 fpm or less,

and discharge is by gravity.

The use of a steel bushed roller chain with a G-Style

attachment every pitch is very common in this elevator.

Buckets are typically spaced every 2nd pitch on 6”, 9” and

12” pitch chains.

Bucket Elevator Types

Positive Discharge Elevators

Chains used in a positive (or perfect) discharge elevator

usually run at a slower chain speed when compared to a

centrifugal-style elevator.

Typical chain speeds in a positive/perfect discharge elevator

are 120 feet per minute or less.

Buckets used in these elevators are end-hung between two

strands of engineered steel chain with bucket wing

attachments (common bucket spacing is 20-24”).

* This is a very uncommon bucket elevator*

Elevator Chain Types

Hardened Steel Bushed

These elevator chains typically feature straight sidebars with heat treated pins and bushings. These types of chains are used for centrifugal discharge and continuous discharge chain bucket elevators.

Steel Bushed Roller

This type of elevator chain features straight sidebars with a heat treated roller, pins and bushings. These chains are typically applied in super capacity, dual strand, gravity chain bucket elevators.

Chain Attachment Types

K-Style Attachments

This double-sided attachment is used on single strand and double strands of chain attached to the back of the bucket.

This is the most common type of attachment primarily used for centrifugal discharge and continuous discharge bucket elevators.

Chain Attachment Types

A-Style Attachments

This single-sided attachment is typically used on double strands of chain with back hung on the buckets.

Centrifugal discharge and continuous discharge elevators will use A attachments.

Chain Attachment Types

G-Style Attachments

These attachments are used on dual strand/double strand super capacity gravity discharge chain bucket elevators.

The attachments are mounted to the side of the bucket.

Chain Attachment Types

Floating Attachments

This type of attachment is used primarily by European original equipment manufacturers.

The attachments are bolted to the back of the bucket and then slid onto a holding pin with a retaining ring or pin.

Floating attachments are primarily used for centrifugal discharge and continuous discharge bucket elevator.

Get the Help You Need

Need common sense answers to your bucket elevator questions?

Webster Industries has more than 100 years of experience providing engineered conveying solutions and straight answers.

Contact us today for assistance with your elevator bucket needs: By phone: (800) 243-9327 Via email: sales@websterchain.com

Or visit our website: http://www.websterchain.com