density separators destoner fluid bed dryer DENSITY SEPARATORS Since 1930, Oliver has provided seedsman worldwide with expertise and equipment to make the most precise density separations.  A complete line of density separators with capacity rates up to 43,000 pounds per hour are available.  Oliver Gravity Separators are known for excellent separation efficiency on green coffee.  The "Oliver" is rated as "The Best Separator" all around the world, and is the choice for the discerning green coffee processor.  If your screened / sized material still has contamination, density separators or stoner separates same size particles by specific density.