Used for the rapid blending of dry powders, granules, pellets and other solid forms, Ross ribbon blenders also mix paste-like materials and solid-liquid suspensions. The materials are blended by a horizontal agitator consisting of inner and outer helical ribbons with angled leading edges within a U-shaped trough. Additional features include scrapers welded to the spokes and ribbons, radiused trough corners, a clear-view FDA-approved polycarbonate on the cover and shaft guards, air-purged mechanical shaft seals with replaceable FDA-approved Teflon seal faces and a pneumatically operated spherical disc valve. Discharge connections can be customized to mate with existing material handling systems.