Abstract: A method and equipment for extracting dissolvable solids from small particles using a staged, counter-current battery of centrifuges is described. The advantages gained by working with particles having a mean diameter smaller than 50 microns and doing the extraction with the particles dispersed in a non-flowing liquid are (1) a significant reduction in the concentration gradient of the dissolvable solids across the diameter of the particles and throughout the body of particles being extracted in a comparable standard column battery and (2) higher overall yields because extraction can be conducted to a uniform limit rather than being constrained by a local (surface or column position) limit. As regards coffee extraction, the equipment and method are intended for the production of high quality concentrated coffee extracts rather than the production of soluble or instant coffee.

Abstract: A method and equipment for extracting dissolvable solids from small particles using a staged, counter-current battery of centrifuges is described. The advantages gained by working with particles having a mean diameter smaller than 50 microns and doing the extraction with the particles dispersed in a non-flowing liquid are (1) a significant reduction in the concentration gradient of the dissolvable solids across the diameter of the particles and throughout the body of particles being extracted in a comparable standard column battery and (2) higher overall yields because extraction can be conducted to a uniform limit rather than being constrained by a local (surface or column position) limit. As regards coffee extraction, the equipment and method are intended for the production of high quality concentrated coffee extracts rather than the production of soluble or instant coffee.