Improved Machine for Cleaning Coffee Harvested with Plastic Nets

Abstract

This paper describes a new machine for cleaning coffee harvested with plastic nets, as well as the coupling of this machine to the horizontal washer. The machine consists of two blowers in two tunnel chambers. The material fed by a screw conveyor is taken by a rotating shaft and ejected by the action of the blower in the upper chamber. The separated material (coffee beans, berries, dirt and small twigs) which falls through the screen to the bottom chamber is carried by a water stream into the washing reel. Further separation of the above mentioned material is accomplished by the washer, the shaker screen, and the flotation tank. This machine, together with the washing reel, is capable of processing coffee from 4.3 acres in an 8-hour run with the screw conveyor set at a speed of 30 rpm. Reduction of the speed to 20 rpm also reduces the output to that of 1.9 acres in an 8-hour run.