Principle of operation

A Flexicon flexible screw conveyor (also known as helix conveyor, screw conveyor, spiral conveyor and auger conveyor) consists of a spring steel or stainless steel flexible screw that is enclosed in a flexible or rigid plastic tube, or a rigid steel tube, and driven by an electric motor normally located at the discharge end of the conveyor. This simple design delivers efficient performance and high reliability while reducing maintenance and cost. When properly engineered according to the specific characteristics of the material being conveyed and the process into which it will be integrated, a flexible screw conveyor can outperform rigid screw conveyors, bucket elevators, drag chain conveyors, aero mechanical conveyors and other equipment intended to transport powder and bulk solid materials.

The intake end of a flexible screw conveyor tube is typically equipped with a charging adapter, a U-shaped trough that connects to the outlet of a hopper or directly to the outlet of process equipment such as a bulk bag discharger, bag dump station, grinder, crusher, screener, blender, reactor or storage vessel of any kind.

Flexible Screws

Flexicon matches an unequalled number and type of standard and custom flexible screws to a correspondingly wide selection of hopper designs and charging adapters to meet all of your material and process parameters with the greatest efficiency and reliability.

The flexible screw passes through the charging adapter trough, exposing a section of the screw to material flowing into the trough from above. When rotating, the exposed section of screw feeds material into the outer tube, where it is then propelled through the tube by the enclosed portion of the screw.

A phenomenon resulting from the loose fit of a rotating flexible screw within a tube filled with bulk material, is that the screw automatically self-centers within the tube, providing clearance between the screw and tube wall. This affords sufficient space for particles to flow without damage, depending on the fragility and size of particles being conveyed.

A removable clean-out cap covers the intake end of the conveyor tube, permitting rapid emptying and flushing of the tube, as well as disassembly and wash-down of components.

Because the intake end of the screw requires no bearing, and since the discharge end is coupled to the motor drive above and/or beyond the point at which material exits the discharge spout, material does not come in contact with seals or bearings. The flexible screw is therefore the only moving part contacting material.

Flexible screw pioneers
Perhaps no other manufacturer has advanced the application of the flexible screw conveyor as far and as fast as Flexicon—the first to introduce 4 1/2 in. (115mm), 6 in. (150mm), and 8 in. (200mm) diameter screw/tube combinations that elevated the capacity of this category of conveyor more than 10-fold in an 8-year period. After more than 20,000 installations worldwide involving a gamut of bulk materials, Flexicon has amassed a wealth of performance data on flexible screws—many of which have been engineered, machined and formed to Flexicon specifications. To you, it means that Flexicon has most likely solved your problem in the most efficient and cost-effective manner possible—or can do so as a matter of routine.

Compare Flexible Screw Conveyors with Pneumatic Conveyors