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A Screw Feeder Is A Machine That Meters And Moves Materials

A screw feeder is a type of machinery that meters and moves materials, usually those of granular, but also of liquid construction. Sometimes known as auger conveyors, these machines use a rotating, helical blade to carry materials in a measured fashion.

Manufacturing facilities in a variety of industries implement a screw feeder. It may be used to transport sugar or grains, water or wood chips, among a multitude of other materials. Some versions are mobile and can be used in the field for agricultural purposes, for example in conjunction with a combine harvester, or with snow blowers. They are also commonly implemented in machining and recycling facilities.

A screw feeder can be enclosed inside a pipe or remain uncovered, depending on the product to be moved and according to processing requirements.  Its length and diameter can vary widely, again depending on a facility’s needs and the bulk of product to be transported. The two basic types of machinery are either gravimetric or volumetric. Both rely on Archimedes’ Screw Principle to transport substances, a concept that has been known to man for thousands of years and was originally implemented in the irrigation of the Nile delta in the third century B.C.

Volumetric conveyors can achieve very accurate feed values by controlling the speed at which the screw – also called flighting – turns. The gravimetric variety, on the other hand, achieves accuracy by controlling the rate of material input. The flighting is typically powered by a motor that allows operators full control of starts and stops, as well as speed adjustments.

Full system solutions incorporating a screw feeder can include hoppers, troughs, and feed mechanisms
. The machine itself is comprised of multiple components. The centerpiece, of course, is the flighting, which is available in several variations: Helicoids, ribbon, double flight, short and variable pitch, and tapered diameter versions, which are only some of the options. The troughs holding the screw can be single-flanged, double-flanged or angled. There are tubular troughs, drop-bottom troughs, channel and jacketed troughs, and flared troughs. The combinations are endless and customizable depending on a facility’s needs.  

Feed and discharge spouts are attached to the flighting’s ends to accommodate input of material on one end, and output of product on the other. Other components include trough covers, trough cover clams, rack and pinion gates, flanges and seals, trough ends, bearings, couplings and hangers. All of these parts come in various combinations and styles. Supporting feet and saddles are often used to support the trough holding the flighting, securely bolting the trough to the factory floor.

The machine is capable of moving material not only in a horizontal, but also in a vertical fashion
. Through rotation, the helix manages to propel substances upward if needed – a useful concept when transporting materials to the surface from underground, or from ground level into an elevated receptacle. The steeper the angle, however, the greater the decrease in the machine’s capacity.

A screw feeder allows operators the exact measurement of material input and output
. In other words, it enables operators to exercise utmost control over the flow of materials, inside the factory or out in the trenches. Its flexibility and adjustability ensures productivity is on target at all times.

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