Screw conveyor in the form of transport is divided into shaft screw conveyor and shaftless screw conveyor two kinds, in the appearance is divided into u-type screw conveyor and tubular screw conveyor. Shaftless screw conveyor is suitable for non-viscous dry powder materials and small particle materials (such as cement, fly ash, lime, grain, etc.) and shaftless screw conveyor is suitable for transporting viscous and easily coiled materials(such as: sludge, biomass, waste, etc.). The working principle of the spiral conveyor is that the rotating spiral blade will push the material and carry out the spiral conveyor, so that the material does not rotate with the spiral conveyor blade is the material's own weight and the friction resistance of the spiral conveyor shell to the material.

The spiral blade welded on the rotating shaft of the spiral conveyor has solid surface type, belt surface type, blade surface type and other types according to the different materials transported. The screw shaft of the screw conveyor has a thrust bearing at the end of the direction of material movement to react with the axial force of the material to the screw. When the captain is long, a hanging bearing should be added. From the perspective of conveying material displacement direction, the screw conveyor is divided into two types: horizontal screw conveyor and vertical screw conveyor.

According to the transport chain selection of plastic screw conveyor, also known as food screw conveyor, screw elevator, mainly suitable for transporting large products. Such as cartons, turnover boxes, barreled water, etc. According to the characteristics of the material and the different structure, the screw conveyor has horizontal screw conveyor, vertical screw conveyor, flexible screw conveyor, screw tube (drum conveyor) conveyor.

Screw conveyors are generally used to transport high temperature powder or solid particles and other chemical and building materials products. The feature is the transport process, because of good sealing, so there will be no secondary dust such as dust during the transport process.