It consists of helicoid (helical flights rolled from flat steel bar) flight, mounted on a pipe on or shaft and turning in a trough. Screw conveyors are preferably used to transport and to dose powder, fine grain or fibrous materials.
Parts of screw conveyor:
- Helical flights
Classification of screw conveyors by its line of transport:
a. Horizontal screw conveyor.
b. Angular screw conveyor.
c. Vertical screw conveyor.
Principle of operation: The intake end of conveyor is fed with a continuous supply of particulate material. The rotating screw in the trough or pipe will lift the material by a wedging action. The screw will be rotated by drive and supported on bearings. The screws are constructed in different fashion for special applications.
Preventive Maintenance points:
1.Grease or oil filling of the gears or geared motor as recommended by the manufacturer.
2.Re-lubrication of bearings as per the requirement.
3.The packing adjustment at the shaft passages of the screw conveyor.
4.The chain drives cleaning with petroleum or p-3 solution and then applying grease or oil as per the recommendation of the supplier.
5.Cleaning the screw conveyor depending upon the material in certain intervals, if found necessary.