Abstract: An apparatus is disclosed for processing extrudable materials in such a way as to apply a controlled and predetermined degree of shear force to the materials. Typically, an extruder apparatus includes a housing having first and second screws mounted therein for rotation on a common axis, the arrangement being such that longitudinal thrust forces exerted by the first screw are at least partially compensated by corresponding forces generated by the second screw, inlet means for introducing material to be processed into the housing and a shear generating device located between said screws, said device including a restriction through which material is forced from said housing to exit from said housing. The restriction is preferably an annular gap formed by a sleeve fixed relatively to the housing and a shaft portion which extends into the sleeve.

Abstract: The invention provides a fluid bed conditioning apparatus (especially a dryer) which comprises a plurality of connected treatment zones, each zone having an apertured base and means for supplying a fluidized gas through said apertured base to each zone to cause material therein to be fluidized. The apparatus includes means for vibrating each apertured base and the zones are separated by movable partitions which are operable in conjunction with transfer means for urging material from one zone to an adjacent zone whereby the contents of a first treatment zone can be transferred to the adjacent zone after a desired treatment time in the first zone.