A screw conveyor, or auger conveyor, uses a rotating helical screw blade, known as a flighting, usually within a tube to move materials. They are often used horizontally or at an incline. This placement allows for a more efficient way to move multiple types of semi-solid materials. From the first incarnation of the machine, known as Archimedes’ screw, through the evolution of today’s modern conveyor auger, the bulk handling industry has been made more efficient through the use of these simple machines.
Archimedes’ screw
Archimedes’ screw, or the Archimedean screw or screw pump, was first used as part of ancient irrigation systems. The screw pump was used for transferring water from a body of water into irrigation ditches. The water was pumped by turning the screw blade inside a hollow pipe. Although the early versions of this machine are attributed to Archimedes, it did not appear until after his visit to Egypt and is widely believed to have been in use as early as 350 years prior to its introduction to Greece.
Modern Machines and Uses
The screw conveyor is still manufactured with a similar basic design to its ancient predecessors. A spiral blade, either coiled around a shaft or as a shiftless spiral, is placed inside a trough or tube. The rate of transfer is directly determined by the rotation rate of the shaft. In industrial applications, the ability to control the rotation rate allows the device to be used as a variable rate feeder in order to deliver a measured rate of material into a process. They can even be operated with the flow of material inclined upward.
The modern versions of these machines have found their way into use in many ways:
* Agriculture – The grain auger has changed the way harvests are collected, transported and stored. Combine harvesters use both enclosed and open augers to move crops into the threshing mechanism and then move the grain into and out of the machine’s hopper.
* Food Processors – The auger inside of a conventional meat grinder forces the chunks of meat through the spinning blades and a holed plate, emulsifying the fat in the beef to soften hamburger patties and is also used to create sausages, etc. They are also used to force food products through dies to produce pellets that are then further processed into other products.
* Oil Fields – Augers are used to transport rock cuttings.
* Pellet fed barbecue grills – Augers are used to move the fuel from the hopper into the firebox.
For more than a century, the H. C. Davis Sons Manufacturing Company, Inc. has designed and built heavy duty equipment.
