Spin flash dryer for producing a powder by spin flash drying

A spin flash dryer comprising:

• a drying chamber enclosed by at least a chamber wall and a chamber bottom;
• thereby defining an exterior and an interior of said drying chamber,
• a rotating stirrer, said rotating stirrer arranged in said drying chamber near said chamber bottom, said rotating stirrer being provided with a plurality of stirring blades;
• members for supply of a material to be dried, said members arranged in said chamber wall to permit passage of a material to be dried from the exterior of said drying chamber to the ulterior of said drying chamber;
• apertures for supply and removal of a medium for fluidization and drying and for removal of a dried product, said aperture for supply of said fluidization and drying medium, being positioned in said drying chamber wall between said chamber bottom and said aperture for removal of a dried product in said drying chamber;
• said spin flash dryer further comprising:
• a waste outlet arranged in said chamber bottom of said spin flash dryer;
• and wherein said waste outlet is arranged for continuous removal of residual organic waste material, which residual organic waste material cannot be spin flash dried due to a density of said residual organic waste material being higher than a lifting power of said medium for fluidization and drying of said spin flash dryer;
• wherein said waste outlet is a valve which forms a sluice;
• and wherein removal is caused by said rotating stirrer moving said residual organic waste material into said waste outlet during spin flash dryer operation upon which said residual organic waste material is removed via said waste outlet in a sluicing operation,
• wherein said sluice comprises a rotating arrangement of openings and closures adapted to maintain an essentially fluid tight seal between the interior of said drying chamber and the exterior of said drying chamber during operation of said sluice and said spin flash dryer.