US Patent 9028133 Tapered barrel twin shaft preconditioner

An improved dual-shaft preconditioner (10) of simplified design is provided giving increased moisturization and partial cooking of food or feed ingredients. The preconditioner (10) includes an elongated, tapered housing (12) presenting a pair of side-by-side, communicating housing sections (58, 60), with a corresponding pair of converging shafts (20, 22) within the sections (58, 60) and having a series of elongated, outwardly extending mixing elements (24, 26) secured to the shafts (20, 22). The preconditioner (10) is designed for use in a system including a downstream processing device, such as an extruder (146).