Bare Screw Conveyor

April 3, 2000

Often the simplest mechanism gets overlooked. This should be kept in mind when devising the equipment to carry press cake away from a screw press, to pile press cake on a floor, or to load press cake into a trailer or wagon.

As a rule either screw conveyors or belt conveyors are used to transport press cake away from a screw press. Generally it is desirable to drop the material in a windrow rather than a conical pile. Complicated mechanisms frequently are selected to achieve this elongated pile of material. In the case of screw conveyors a series of remote actuated sliding gate drop chutes can be sequentially programed. For belt conveyors there are traveling diverter dams that result in progressive dumping of material from the belt.

A far more simple mechanism for making a progressive pile is a bare screw conveyor. Without a trough under the screw, material will fall immediately to the ground or bed of a truck. As the material piles up, it will eventually rise to where the pile reaches the screw. At this time the material will form its own trough around the screw, and press cake will begin to travel with the screw. This pile will creep past the occasional hanger bearing. The end result is a long pile of material.

The angle of repose of the pile will be according to the characteristic of the material being handled. Frequently this is adequate for filling a truck trailer without further leveling being required.

This bare screw mechanism can work well for filling a truck. Only minimal attention from a loader or truck driver will be required.

Similarly, the bare screw is good for carrying cake from a press used as an outdoor manure separator. If the press drops a conical pile of material it is necessary to move the pile about once a day. However, with a bare screw conveyor, the material can be piled for a week or so without human intervention.

Bare Screw Conveyor Bare Screw Conveyor

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Bare Screw Conveyor Bare Screw Conveyor
Issue 103