Feed Mill Screw Conveyors

Common types of screw conveyors used in animal feed production include: U trough screw, tube screw, coreless screw, flexible screw and Olds type screw. Screw conveyors consist of a revolving continuous or broken spiral flighting (auger) that operates inside a casing. Usually operates in one direction only to move bulk material such as meal or seed.

U trough screws are typically used for horizontal conveying while tube conveyors are used for vertical applications or where dust is a factor.

An alternative concept to the traditional shafted screw conveyor is the coreless screw conveyor. Coreless screw conveyors contain a extra heavy duty shaftless screw that slides on a low friction, wear resistant liner inside the conveyor trough casing.

Flexible screw conveyors are also a coreless/centerless conveyor but has an outer casing that is flexible or has been manufactured with a permanent curvature. This affords the feed plant designer additional freedom with respect to limited angles of incline and straight only conveying paths that are constraints of other conveyor designs.

Standard spiral conveyors have decreasing efficiency as the angle from horizontal increases. The Olds type vertical conveyor (elevator) is an adaptation of the traditional screw conveyor design. The Olds conveyor operates with a fixed shaft screw surrounded by a rotating tubular casing. This design is optimal in the vertical position and requires a minimal footprint.

- PSC Group s.a.l, Oregon/Washington CADD Users, Flexicon Corporation, Olds Elevator LLC images.