Application of Screw Conveyor in Cement industry

The Screw Conveyor is a powder material handling device, which has a simple and compact structure, reliable working performance, and low cost. It is currently widely used in the food industry, building material industry, chemical industry, transportation and other departments, such as cement and chemicals , Sand, flour, salt, etc. The use of tubular Screw Conveyors in cement transportation makes cement difficult to fly, which reduces waste and environmental pollution, and is a good cement transportation equipment.

With the rapid development of road construction and continuous improvement of construction machinery, large-angle screw conveyors have become an indispensable and important part of concrete mixing equipment. Large-angle tubular screw conveyors are also often used on construction sites that use bulk cement. This article will briefly introduce the structural design and parameter selection of the high-angle tube screw conveyor. The large-angle screw conveyor is composed of three parts: the screw body, the inlet and outlet, and the driving device.

The main body of the screw conveyor includes several parts such as head bearing, tail bearing, screw shaft, outer tube, observation port and so on. The driving device is composed of motor, reducer, coupling and so on. The oblique installation angle of the large inclination screw conveyor is generally about 4 °, and the length is generally not more than 8 meters. In order to avoid excessive bending of the screw shaft and friction with the outer tube, the middle of the screw shaft should be supported, and the degree of winding should be checked. The intermediate support is set to reduce the radial winding of the screw conveyor shaft, and the working conditions in this part are bad. Because the spiral blade is interrupted at the intermediate support, the length and lateral dimension of the support along the axis should be reduced as much as possible to prevent the material from clogging here. The support here can take the form of bearing or flange bearing.

Each suspension bearing of the screw conveyor should reliably support the connecting shaft, and the screw shall not be jammed or bent. The suspension bearing should be installed at the center point of the connecting shaft, and the gap between its end surface and the end surface of the two spiral tube shafts should be greater than 10mm. In order to adjust the cumulative error of the length between the casing and the spiral, it is allowed to add pads between the flanges of each casing during installation. When the difference between the center height of the low-speed shaft of the speed reducer of the driving device and the center height of the screw conveyor is too large, the height of the driving device can be adjusted by the shim. During the no-load test run, if the bearing is found to have oil leakage, the bearing should be removed and the tightness of the spring in the seal ring adjusted until there is no oil leakage. The temperature rise of each bearing during no-load test run should not exceed 20 ℃; if the temperature rise is too high, it indicates that the location of the suspension bearing is improperly installed, resulting in the phenomenon of jamming of the connecting shaft. During load test, the temperature rise of each bearing should not exceed 30 ℃.

In order to prevent the tiny particles of materials from entering the bearing, reliable dustproof and lubricating facilities should be adopted here. The screw conveyor is very sensitive to overload and is prone to blockage. In order to achieve a better conveying state, the pitch of the screw shaft is best to adopt a variable pitch. The pitch of the lower half is smaller than the pitch of the upper half. This structure prevents the material from being overloaded and clogged.