A screw conveyor or auger conveyo r is a mechanism that uses a&nb sp;rotating helical screw blade, called&n bsp;a flighting, usually within a tube,  ;to move liquid or granular material s. They are used in many bulk&n bsp;handling industries. Screw conveyors  in modern industry are often used&nb sp;horizontally or at a slight incli ne as an efficient way to move& nbsp;semi-solid materials, including food  ;waste, wood chips, aggregates, cereal&nb sp;grains, animal feed, boiler ash,  meat and bone meal, municipal solid& nbsp;waste, and many others. The fir st type of screw conveyor was t he archimedian screw, used since anc ient times to pump irrigation water.

  They usually consist of a trough& nbsp;or tube containing either a spi ral blade coiled around a shaft,&nbs p;driven at one end and held at  the other, or a shaftless spir al, driven at one end and free& nbsp;at the other. The rate of  volume transfer is proportional to t he rotation rate of the shaft.  In industrial control applications the&nb sp;device is often used as a va riable rate feeder by varying the&nb sp;rotation rate of the shaft to&nbs p;deliver a measured rate or quantit y of material into a process.

  Screw conveyors can be operated w ith the flow of material inclined&nb sp;upward. When space allows, this i s a very economical method of e levating and conveying. As the angle  of inclination increases, the capac ity of a given unit rapidly dec reases.

 This machine is suitable for conveying all kinds of powder, granular and small lump materials, such as coal, gravel, lump coal, sand, cement and cereals. It does not apply to deliver perishable, viscous, easy caking materials. The screw conveyor is commonly known as the auger, it is a transportation equipment and widely used in the minerals, feed, grain, construction. The screw conveyor has simple structure, low making cost, strong sealing, safe and convenient operation. So it is widely used in chemical industry, building materials, metallurgy, food and other departments, in the case of the inclination angle β <20 ° , it can transport powder, granular and small pieces of material, whose viscosity is not strong, non-perishable, According to the displacement direction, the screw conveyor can be divided into two types: The horizontal screw conveyor and the vertical screw conveyor.

Characters of the screw conveyor:

Simple structure, small cross section size, good sealing, reliable, low cost, easy to loading and unloading in intermediate, conveying direction can also be reverse and convey the opposite two directions at the same time. It can also do stirring, mixing, heating and cooling operations in transport process. It can adjust material flow by the loading gate, but it is unapt to transport perishable, viscous, easy to agglomerate, and large pieces of material. The material is easily broken, screw and trough is easy to wear in the transportation process. Unit power is bigger to maintain sealing of the material and the adequate clearance between screw and spiral trough.

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