Because the performance, size and cost of conveying methods vary widely, only a general knowledge of different conveyor types is necessary to determine which is optimum for you, assuming you possess detailed knowledge of your application.
Armed only with the fundamentals outlined below, you can therefore determine whether your application is handled most efficiently by a conveyor that contains a flexible screw.
(Fig. 3) A U-shaped trough that connects to the outlet of a hopper or directly to the outlet of process equipment
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. (Fig. 4)
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 drive motor 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. (Fig. 5)
After each conveyor has deposited its ingredient, the entire batch can be automatically delivered to process equipment, storage vessels, packaging lines or process equipment.
Flexibility of the conveyor tube allows the weigh hopper to be positioned directly above a blender or any other process equipment.
Since the system functions as both weigh feeder and conveyor, it can eliminate the need for separate equipment.
These screws are fabricated from spring steel or stainless steel that is square or rectangular in profile. Flat bearing surfaces impart greater directional force and lesser radial force (and material compression) than do round wire screws. Flat wire screws are therefore frequently employed to convey products that tend to compress, as well as fragile materials, low mass materials and those comprised of the finest particle sizes. (Fig. 11)