Pneumatic conveying system for separating bulk product

1. An apparatus ( 500 ) for pneumatically conveying and separating bulk material comprising:

a vessel ( 526 ) for receiving and separating gas and bulk material, wherein the vessel ( 526 ) comprises a gas outlet ( 572 );

at least one material inlet ( 512 ) located on the vessel ( 526 ) configured to input gas and bulk material into the vessel ( 526 ) at a rate of 5 m/s to 100 m/s and thereby form a cyclone which separates the gas and bulk material within the vessel ( 526 );

a sifting device ( 534 ) for receiving the bulk material from the vessel ( 526 ), wherein the sifting device ( 534 ) comprises a first sifter outlet ( 546 ), wherein bulk material is separated via centrifugal forces into at least two or more different powder discharges; and

a pneumatic air conduit ( 570 ) directly connected with the gas outlet ( 572 ) and the first sifter outlet ( 546 ), wherein the pneumatic air conduit ( 570 ) is configured to provide uninterrupted gas flow to the first sifter outlet ( 546 ).

2. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the vessel ( 526 ) is a cyclonic separator and the sifting device ( 534 ) is a centrifugal sifting device, wherein the sifting device ( 534 ) further comprises a second sifter outlet ( 550 ), wherein the sifting device ( 534 ) is configured to separate pneumatically conveyed material into oversize powder discharge via the second sifter outlet ( 550 ) and fine powder discharge ( 544 ) from the first sifter outlet ( 546 ).

3. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 2 , wherein the sifting device ( 534 ) is in the form of a cylindrical sieve comprising a mesh-like structure with a series of small apertures, the small apertures having a cross-section diameter of 100-1,000 mm, and

wherein larger particulate material is retained within the cylindrical sieve and exits through the second sifter outlet ( 550 ) as an oversize powder discharge and fine particulate material passes through the cylindrical sieve as a fine powder discharge and exits through the first sifter outlet ( 546 ) as a fine powder discharge.

4. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 2 , wherein by rotating the material in the sifting device ( 534 ) causes at least part of the bulk material to pass through perforations and/or apertures in the sifting device ( 534 ), and

wherein material which passes through perforations of the sifting device ( 534 ) exits the sifting device ( 534 ) via the first sifter outlet ( 546 ) as fine powder discharge and is valuable product material and larger sized particulate material which is unable to pass through the perforations in the sifting device ( 534 ) exits the sifting device ( 534 ) via the second sifter outlet ( 550 ) as oversize powder discharge and is waste material.

5. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the vessel ( 526 ) is substantially cylindrical in shape with a conically shaped bottom section ( 532 ) which is used to funnel material to the sifting device ( 534 ).

6. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the vessel ( 526 ) is located substantially vertically during use and has a substantially longitudinal axis extending vertically through the vessel ( 526 ) thereby allowing the separated bulk material to be gravity fed to the sifting device ( 534 ).

7. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the vessel ( 526 ) comprises two or more material inlets for the inputting of air and bulk material into the vessel ( 526 ).

8. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the at least one material inlet ( 512 ) is located on the vessel ( 526 ) substantially tangential to a longitudinal axis of the vessel ( 526 ) thereby facilitating the formation of a cyclone of air and bulk material within the vessel ( 526 ).

9. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the vessel ( 526 ) comprises at least one or more air and/or material outlets which feed separated air and material to the sifting device ( 534 ).

10. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein in use a positive pressure gradient is maintained from the at least one material inlet ( 512 ) to the first sifter outlet ( 546 ).

11. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the sifting device ( 534 ) comprises a material inlet for receiving air, material, or a combination thereof from the vessel ( 526 ).

12. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the sifting device ( 534 ) is in the form of a cylindrical chamber which is positioned substantially horizontally.

13. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the sifting device ( 534 ) is lined with a series of perforations in the form of a perforated sheet, and

wherein the sifting device ( 534 ) comprises a shaft with outlying and/or protruding members located on the shaft which on rotation are used to stir and/or rotate the material within the sifting device whereupon under centrifugal forces, the stirred and/or rotated material is forced against the perforated sheet or a substantially cylindrical sieve in the form of a perforated drum or mesh-like structure which allows separation of the bulk material to occur into larger and smaller particulate material.

14. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the apparatus also comprises a hopper ( 402 ) to feed bulk material from a transport silo or any other storage system into the apparatus, and

wherein the sifting device ( 534 ) comprises a drive to rotate a cylindrical sieve located in the sifting device ( 534 ).

15. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein in use a positive pressure gradient is maintained in the vessel ( 526 ).

16. An apparatus ( 500 ) for pneumatically conveying and separating bulk material according to claim 1 , wherein the at least one material inlet ( 512 ) contains a screen with a screen size of 10 to 30 mm.

17. A method of conveying and separating bulk material comprising:

providing a vessel ( 526 ) for receiving and separating gas and bulk material, wherein the vessel ( 526 ) comprises a gas outlet ( 572 );

providing at least one material inlet ( 512 ) located on the vessel ( 526 ) configured to input air and bulk material into the vessel ( 526 ) at a rate of 5 m/s to 100 m/s and thereby forming a cyclone which separates the gas and bulk material within the vessel ( 526 );

providing a sifting device ( 534 ) for receiving bulk material from the vessel ( 524 ), wherein the sifting device ( 534 ) comprises a first sifter outlet ( 546 ), wherein the sifting device ( 534 ) separates the bulk material via centrifugal forces into at least two or more different powder discharges; and

providing a pneumatic air conduit ( 570 ) directly connected with the gas outlet ( 572 ) and the first sifter outlet ( 546 ), wherein the pneumatic air conduit ( 570 ) is configured to provide uninterrupted gas flow to the first sifter outlet ( 546 ).

18. A method of conveying and separating bulk material according to claim 17 , wherein in use a positive pressure gradient is maintained from the at least one material inlet ( 512 ) to the first sifter outlet ( 546 ).

19. A method of conveying and separating bulk material according to claim 17 , wherein bulk material is caused to rotate in a cyclonic vortex due to the rotation of air within the vessel ( 526 ) and during the cyclonic motion of the bulk material, the bulk material is forced to inner surfaces of sidewalls of the vessel ( 526 ) in a vortex-like manner; and

wherein during use, the bulk material is thrown against the sidewalls of an upper section of the vessel ( 526 ) and then funneled down along into a lower section ( 532 ) of the vessel ( 526 ) wherein the cyclone of air therefore builds a rotating mass of bulk material against the sidewalls of the vessel ( 526 ) which has the ability to absorb sudden increases and/or decreases in bulk material feed by adjusting a thickness dimension ‘T’ and density of the bulk material being forced against the inner surfaces of the sidewalls of the vessel ( 526 ).

20. A method of conveying and separating bulk material according to claim 17 , wherein the at least one material inlet ( 512 ) contains a screen with a screen size of 10 to 30 mm.

21. A method of conveying and separating bulk material according to claim 17 , wherein in use a positive pressure gradient is maintained in the vessel ( 526 ).