A self-cleaning multiple helical auger conveyor for a processor has an array of pairs of opposite-handed, counterroatating helical augers with flights intermeshed such that the front of every flight is cleaned by the back of another flight and the back of every flight is cleaned by the front of another flight. Optionally, the flights are shafted and the periphery of every flight and the shaft of an adjacent flight mutually clean one another. Rectangular and polar arrays of such paired flights are described, along with relationships among flight thickness, clearance, pitch and number of flights. A flight having a coined surface and a cleaning tab projecting therefrom is described. Support, gearing and housing for various embodiments of the conveyor are described.