Abstract: A process and apparatus for recovering feed products from animal manure are disclosed wherein the manure is fractionated into a silage component, a high-protein feed supplement, and a third component consisting essentially of insoluble minerals and indigestible cellulosic particles. A slurry of the incoming manure is formed and allowed to ferment to encourage the bacterial conversion of nitrogenous compounds into true protein and to lower the pH of the slurry. Special separators are used to separate the fermented slurry into solid and liquid fractions. The solid fraction which consists of undigested fibers and grains is washed to provide the silage type component. Insoluble minerals and indigestible cellulosic particles of the manure which appear in the liquid fraction as fine solids are removed from the liquid fraction (by centrifuging) to provide the third component. The viscous liquid fraction may be used as a high-protein feed supplement or the water in it can be evaporated to provide a dry product.

Abstract: Apparatus for separating a viscous slurry into solid and liquid fractions comprising a cylindrical screen and an axle extending longitudinally through said cylindrical screen with a plurality of scraper knives mounted on the axle in the upper portion of the cylindrical screen for scraping clean the interior surface of the screen. The viscous slurry is fed under pressure into the volume within the screen occupied by the scraper knives. A force is applied to a discharge valve at the bottom of the screen to provide a back pressure so that the liquid fraction can be forced through the holes of the screen while the scraper knives clean the screen. An auger flighting secured to the bottom portion of the axle compresses the solid fraction toward the discharge valve. The liquid fraction is collected externally of the screen while the solid fraction drops past the discharge valve.The separator may be used in combination with washing apparatus comprising a horizontal trough terminating in a screw press.