SCREW-TYPE EXTRUDER Russian patent published in 2004 - IPC

FIELD: processing edible materials; food-processing industry. SUBSTANCE: proposed extruder has housing with loading funnel, matrix and hollow screw feeder with external thread. Inner cylindrical surface of screw feeder is provided with helical thread of the same direction as that of external thread. Thread pitch and/or depth of helical passage decrease towards escape of product. End section of inner cylindrical surface of hollow screw feeder is smooth. Mounted inside screw feeder is rotatable hollow shaft on whose end section cylindrical end-piece is rigidly secured; this end-piece has helical thread opposite to threads of hollow screw feeder. EFFECT: extended field of application; stabilization of pressure of two flows of product in pre-matrix zone of extruder. 3 dwg