Pneumatic separator for flowable particulate materials

A pneumatic separator for multi-fraction particulate pourable materials, comprising first means defining a first upright passage for admission of a multi-fraction particulate material and having a first open lower end;

• second means defining an upright annular second passage surrounding said first passage outwardly spaced therefrom and having a second open lower end downwardly spaced from said first end, said second passage having an outlet in the region of its upper end and converging in the direction towards said region;
• a downwardly open hollow guide body centrally located beneath said first end and having a conical surface which directs the material towards said second end, and a shoulder extending at least substantially normal to a central axis of said annular second passage and having an edge over which material is discharged into said second channel, said second channel having at least in the region below said shoulder at least one zig-zag shaped passage portion so that, when suction is applied to said outlet and material is discharged into said passage portion, the material undergoes repeated directional changes during each of which the airstream aspirated by application of the suction travels transversely through the material;
• and a suction conduit communicating with the ambient atmosphere and having an inner discharge end communicating with the interior of said body.

A pneumatic separator for multi-fraction particulate pourable materials, comprising first means defining a first upright passage for admission of a multi-fraction particulate material and having a first open lower end;

• second means defining an upright annular second passage surrounding said first passage outwardly spaced therefrom and having a second open lower end lownwardly spaced from said first end, said second passage having an outlet in the region of its upper end and converging in the direction towards said region;
• a guide body centrally located beneath said first end and having a concial surface which directs the material towards said second end, and a shoulder extending at least substantially normal to a central axis of said annular second passage and having an edge over which material is dischared into said second channel, said second channel having at least in the region below said shoulder at least one zig-zag shaped passage portion so that, when suction is applied to said outlet and material is discharged into said passage portion, the material undergoes repeated directional changes during each of which the airstream aspirated by application of the suction travels transversely through the material;
• and means for opening and closing said first lower end, including a conical closure member movable axially towards and away from said first lower end;
• a conical guide member nested in said closure member, and means connecting said guide member to said body with freedom of displacement in direction transverse to the elongation of said first passage.