Screw conveyors have the following characteristics
1) Relatively simple structure and low cost.
2) Reliable operation and easy maintenance and management.
3) Compact size, small cross-sectional size and small footprint. It is easy to enter and exit hatches and carriages during unloading operations at ports.
4) It can achieve sealed transportation, which is conducive to the transportation of materials that are easy to fly, hot and have strong odors, can reduce pollution to the environment and improve the working conditions of port workers.
5) Convenient loading and unloading. Horizontal screw conveyors can be loaded and unloaded at any point on their conveying line; vertical screw conveyors can have excellent retrieving performance by configuring relative screw reclaiming devices.
6) It can convey in reverse, and can also enable a conveyor to convey materials in two directions at the same time, that is, toward the center or away from the center.
7) The unit energy consumption is relatively large.
8) The material is easy to be crushed and worn during the conveying process, and the wear of the spiral blades and the material trough is also relatively serious.
Structural characteristics
(1) The spiral blades of the screw conveyor are of three types: solid spiral surface type, belt spiral surface type and blade spiral surface type. The solid spiral surface is called the s-type method. Its spiral pitch GX type is 0.8 times the blade diameter. The LS type screw conveyor is suitable for conveying powdered and granular materials. The belt spiral surface is also called the D-type method. Its spiral pitch is the same as the spiral blade diameter. It is suitable for conveying powdered and small pieces of materials. The blade spiral surface is less used. It is mainly used to convey materials with high viscosity and compressibility. During the conveying process, stirring and mixing processes are completed at the same time. Its spiral pitch is about 1.2 times the diameter of the spiral blade.
(2) The spiral blades of the screw conveyor have two rotation directions: left-handed and right-handed.
(3) The types of screw conveyors include horizontal fixed screw conveyors and vertical screw conveyors. Horizontal fixed screw conveyors are the most commonly used type. Vertical screw conveyors are used to lift materials over short distances. The conveying height is generally not more than 8m. The spiral blades are solid surface type. It must have horizontal screw feeding to ensure the necessary feeding pressure.
(4) A 1/2~1 turn reverse spiral blade should be installed at the material outlet of LS and GX type screw conveyors to prevent powder from blocking the end.
(5) The screw conveyor consists of three parts: the screw body, the inlet and outlet, and the drive device.
The screw body consists of the head bearing, the tail bearing, the suspension bearing, the screw, the casing, the cover plate and the base.
The drive device consists of an electric motor, a reducer, a coupling and a base.