Technical handbook for the paddy rice postharvest industry in ...

63 CONVEYING3.28. Drive arrangementsfor screw conveyors: A,speed reducer mountedon conveyor shaft, motormounted with V belt connectionto slde or top; B,self-contained unit withstandard speed reducermounted on the shaft,motor attached and drivenby V belt; C, gear motorwith built-in speed reducer,chain drlve to screwshaft,3.29. Auger systems: A,portable; B, installed-inbin.Portable and bin augersThe previous section on screw conveyors provides design data on heavy-duty,continuous-operation screw conveyors, the type which would be used in a paddystorage-processing plant.In many small storage installations, however, it may be necessary to load andunload bins only a few times per year. This type of operation does not require thetype of screw conveyors just described. A number of manufacturers produce specialscrew conveyors for occasional use. They are generally known as augers. Figure 3.29shows portable augers A used on an incline to move paddy from a tractor-trailer intoa dryer and from the dryer into a storage bin, and a horizontal unloading auger Bunder the floor of a storage bin and a vertical auger to move paddy from the storagebin to a truck or into a rice mill. These light-duty augers (fewer operating hours peryear) are housed in lightweight closed tubes instead of an open U trough.Most often they are operated at higher rpm’s than those recommended forheavy-duty screw conveyors shown in Figure 3.22. Thus they achieve higher capacitiesthan small-diameter screw conveyors. Generally these augers are less expensive