Conditioning apparatus for conditioning a leaf vegetable material of a fibrous nature, which apparatus comprises a perforate bed whereby gaseous conditioning medium may be supplied through the perforations to establish a conditioning zone immediately above the bed whereby, in use, the material can be maintained in effectively a fluidized state, the bed being supported in a frame in a manner which permits adjustment of the configuration of the bed relative to the frame at least in a direction of feed of the material to be conditioned. The bed is supported above a plenum chamber arranged to be supplied with conditioning medium being supplied from means comprising an inlet duct for conditioning medium under pressure, said inlet duct communicating with a first and second duct each communicating with said plenum chamber, heating means provided in said first duct, and bleed-off means associated with at least one of said first and second ducts whereby the relative proportions of heated and unheated conditioning medium entering the plenum chamber can be adjusted.
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.
An air distribution plate for incorporation into a material conveyor or a material separator has a plurality of apertured zones alternately arranged along the length of the plate. The apertures in the first series of zones are inclined in the direction of the desired flow of material in the case of the conveyor and in the direction of the desired air flow in the case of the separator and the apertures in the second series of zones incline in the opposite direction by the same amount. Each zone in the second series of zones has fewer apertures than the zones of the first series of zones.
