Separating and Washing Coffee Harvested With Plastic Nets

Abstract

A method was developed for cleaning and washing coffee harvested with plastic nets. The material collected was bulky due to large amounts of leaves. An air separator designed and constructed to separate foreign material from coffee beans and berries is described. It consists of a bladetype blower placed in a two-chamber tunnel. When the net-collected material is fed into the separator, the light components are separated in the upper chamber, while the heavier materials fall into the bottom chamber where a stronger air current separates most of the remaining foreign substances from the coffee. Separation of the material was more difficult when weather conditions were rainy or humid while the nets were on the ground. The separation was much easier when the material was collected during diy, windy weather. The capacity of the air separator for wet and sticky material was about 2 acres per 8-hour run; the capacity was about 4 acres per 8-hour run with dry material. The material obtained from the air separator consisted of coffee beans and berries, together with some extraneous matter. This material was fed into a horizontal washing machine where the remaining extraneous material was removed leaving the coffee ready for drying.