WO2000032026A1

WO2000032026A1 - Cane harvester fan system for the cleaning of sugar cane

Info

Publication number: WO2000032026A1
Application number: PCT/AU1999/001061
Authority: WO
Inventors: Eric John Archibald
Original assignee: Eric John Archibald
Priority date: 1998-11-26
Filing date: 1999-11-26
Publication date: 2000-06-08
Also published as: AUPP731498A0

Abstract

The present invention provides a method of separating sugar cane billets and extraneous matter during harvesting of sugar cane which comprises the steps of: a) providing a plurality of axial flow fans (18, 20) within a tubular cleaning chamber (14) of a cane harvester; and b) counter rotating at least one of the axial flow fans (18) relative to the remaining axial flow fans (20) to create an airflow which is adapted to draw trash from a mixture of billets and trash. The present invention also provides an associated apparatus, system and cane harvester.

Description

_ i .

CANE HARVESTER FAN SYSTEM FOR THE CLEANING OF SUGAR CANE

Field of the Invention

The present invention relates to mechanical harvesting of sugar cane. In particular, the present invention relates to the separation of the extraneous matter, which is commonly referred to as trash and sugar cane billets, which are typically produced during the process of harvesting sugar cane. Background to the Invention Sugar cane is typically harvested with the use of a mechanical cane harvester. In the past it was necessary to burn the sugar cane prior to harvesting with a cane harvester. With recent advancements in sugar cane harvesters it is now possible to harvest sugar cane without firstly burning the sugar cane, a process commonly referred to as harvesting green. In the process of harvesting cane, individual sugar cane stalks are cut into portions commonly referred to as billets. In the process of harvesting the cane and producing billets extraneous matter which includes the foliage of the sugar cane plants is produced. The extraneous matter is commonly referred to as trash. A much greater amount of trash is produced when harvesting green. The process of harvesting the sugar cane with a mechanical cane harvester includes separating the billets from the trash.

The process of separating the trash and sugar cane billets is typically carried out in a section of the cane harvester commonly know as the cleaning section. The cleaning section includes a tubular cleaning chamber, which has a substantially circular cross section. The cleaning chamber is positioned within the cane harvester so that its longitudinal axis is upright. The cleaning chamber typically includes an axial-flow fan, which is designed to produce an upwardly directed flow of air, which is capable of drawing the trash from a mixture of trash and sugar cane billets. The cane billets are typically discharged through the cane billet discharge section of a cane harvester and the trash is drawn upwardly towards an extractor hood of the cane harvester to be subsequently discharged therefrom. One problem with this process of separating the trash and sugar cane billets is that the axial-flow fan induces what is commonly referred to as swirl or cyclone effect within the flow of air which it is designed to produce. Because of the swirl or cyclone effect the flow of air across a face of the fan is not even. This results in the effectiveness of the cleaning process being impaired and a high percentage of cane being lost . It also results in trash which is discharged from the extractor hood being spread unevenly across the outlet of the extractor hood to result in the trash being unevenly spread across the ground. The swirl or cyclone effect also increases the likelihood of the fan stalling when operating at high removal rates.

It is therefore desirable to provide an improved trash extraction process which addresses one or more of the above mentioned problems. Summary of the Invention

The present invention provides a method of separating sugar cane billets and extraneous matter during harvesting of sugar cane, the method comprising the steps of : (a) providing a plurality of axial flow fans within a tubular cleaning chamber of a cane harvester; and

(b) counter rotating at least one of the axial-flow fans relative to the remaining axial-flow fans to create an airflow which is adapted to draw trash from a mixture of billets and trash. The method may include positioning each of the plurality of the axial-flow fans relative to adjacent axial-flow fans so that they are axially positioned relative to each other as close as possible without contacting.

It is preferred that the plurality of axial flow fans is an even number of axial flow fans. The present invention also provides an apparatus for separation of sugar cane billets and extraneous matter during harvesting of cane, the apparatus comprising a plurality of fans, mounting means for mounting the fans axially within a tubular cleaning chamber of a cane harvester, and rotation means for rotating each of the fans, wherein the rotation means is adapted to counter rotate at least one of the plurality of fans relative to the other of the plurality of fans, while the fans are axially aligned within the cleaning chamber via the mounting means, to produce an axial air flow within the cleaning chamber.

The rotation means may comprise a plurality of shafts, for rotation of one or more fans and one or more drive means for rotation of the plurality of shafts.

The plurality of shafts may be concentrically arranged relative to each other. The mounting means may be adapted for mounting the fans within the tubular cleaning chamber via the one or more drive means to either the tubular cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

The mounting means may comprise one or more mounting members, each mounting member being adapted to mount at least one of the drive means to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

A single mounting member may be adapted for mounting two drive means, wherein the two drive means are adapted to be positioned substantially centrally along the longitudinal length of a cleaning chamber, adjacent each_other, between two or more shafts which extend away from the two adjacent drive means, substantially along the longitudinal axis of the cleaning chamber.

A single mounting member may be adapted for mounting one only of the drive means to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

It is preferred that the plurality of fans is an_even number of fans and that half of the plurality of fans are counter rotated relative to the other half of the plurality of fans.

The plurality of fans may comprise two fans . The tubular cleaning chamber may have a substantially circular cross-section.

Each of the fans may comprise more than 2 veins. It is preferred that each of the fans comprise either 3 or 4 veins . The fans may be driven by any drive means, which is suitable for driving a fan including hydraulic drive, belt drive or chain drive means.

Each drive means may include a gearbox wherein the gearbox is either independently mounted via the mounting means, to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber,_or alternatively, the gearbox may be mounted by way of its attachment to the remainder of the drive means.

The present invention also provides a cane harvester for harvesting sugar cane, the harvester comprising a tubular cleaning chamber and a plurality of fans which are positioned axially within the cleaning chamber and adapted for rotation within the cleaning chamber to produce flow of air within the cleaning chamber which flows along the longitudinal length of the cleaning chamber in a direction substantially aligned with the longitudinal axis of the cleaning chamber wherein at least one of the fans is adapted for counter rotation relative to the other fans.

The cane harvester may comprise a substantially upright tubular cleaning chamber wherein the plurality of fans are adapted for rotation within the cleaning chamber to produce an upwardly directed flow of air within the cleaning chamber.

The harvester may comprise a substantially horizontal tubular cleaning chamber wherein the plurality of fans are adapted for rotation within the cleaning chamber and produce a flow of air within the cleaning chamber which flows substantially horizontally through the cleaning chamber.

The fans may be driven via common drive means. The fans may be independently driven via independent drive means .

The fans may be independently mounted via independent mounting members. The mounting members may comprise an arm, one end of the arm being adapted for attachment to either a cleaning chamber of a cane harvester, or a portion of a cane harvester which is proximal the cleaning chamber, and the other end of the arm being adapted for attachment to one of the one or more drive means or two adjacent drive means .

The mounting member may be adapted for attachment to the extractor hood.

Alternatively, one end of the arm of the mounting member may be adapted for attachment to a portion of a cane harvester which, in use, is located beneath the cleaning chamber of the cane harvester and the other end of the arm of the mounting member may be adapted for attachment to the drive means . In a further alternative configuration the one end of the arm of the mounting member may be adapted for attachment to a wall of the cleaning chamber, the arm being adapted to extend substantially laterally and inwardly toward the longitudinal axis of the cleaning chamber, and the other end of the arm being adapted for mounting to two adjacent drive means, the two adjacent drive means being positioned between two or more shafts which extend away from the drive means along the longitudinal axis of the cleaning chamber. The present invention also provides a system for separation of sugar cane billets and extraneous matter during the harvesting of sugar cane comprises: a plurality of fans, mounting means for mounting the fans axially within a tubular cleaning chamber of a cane harvester, and rotation means for rotating each of the fans, wherein the rotation means is adapted to counter rotate at least one of the plurality of fans relative to the other of the plurality of fans, while the fans are axially aligned within the cleaning chamber via the mounting means, to produce an axial air flow within the cleaning chamber. In an alternative form, the apparatus comprises a plurality of fans, a plurality of shafts for axially rotating the fans, and drive means for rotating the shafts_wherein the plurality of shafts are substantially axially aligned and axially attach to one or more of the fans, and the drive means is adapted to rotate the plurality of shafts so that at least one of the plurality of fans counter rotate relative to the other fans.

The plurality of shafts may be concentrically arranged relative to each other. The apparatus may be adapted for location within a tubular cleaning chamber of a cane harvester, wherein upon counter rotation of the fans flow of air is produced within the cleaning chamber which is adapted to draw extraneous matter through the cleaning chamber in a direction substantially aligned with the longitudinal axis of the cleaning chamber.

The apparatus may be adapted for location within a substantially upright tubular cleaning chamber, wherein upon rotation of the fans an upwardly directed flow of air is produced within the cleaning chamber which is adapted to draw extraneous matter upwardly through the cleaning chamber. The apparatus may also be adapted for location within a tubular cleaning chamber which has a longitudinal axis that is substantially horizontal, wherein upon counter rotation of the fans a substantially horizontally directed flow of air is produced within the cleaning chamber which is adapted to draw extraneous matter through the cleaning chamber, in a direction substantially aligned with the longitudinal axis of the cleaning chamber. The apparatus may comprise 2 concentric shafts, the fan attachment end of each of the shafts axially attaching to half of the plurality of fans wherein the fans attached to each shaft are spaced predetermined distances along the longitudinal length of the fan attachment end of the shaft. Each of the fans may be evenly spaced along the longitudinal length of the fan attachment end.

It is preferred that the plurality of fans is an even number of fans . In another alternative form the apparatus comprises one or more fans, one or more shafts for rotating the fans, drive means for rotating the shafts, and mounting means for mounting the fans within a tubular cleaning chamber of a cane harvester, the cane harvester including an axial flow fan which has its veins transversely orientated relative to a longitudinal axis of the cleaning chamber wherein the mounting means is adapted to axially align the fans with the axial flow fan and the drive means is adapted to counter rotate e at least one of the combined fans and axial flow fan of the cleaning chamber relative to the other of the combined fans and axial flow fan of the cleaning chamber. It is preferred that the combined fans and axial flow fans are an even number of fans.

In an alternative form, the system for separation of sugar cane billets and extraneous matter during the harvesting of sugar cane, comprises: one or more fans, drive means for rotating the shafts, and mounting means for mounting the fans within a substantially tubular cleaning chamber of a cane harvester, the cane harvester including an axial flow fan which has its veins transversely orientated relative to a longitudinal axis of the cleaning chamber wherein the mounting means is adapted to axially align the fans with the axial flow fan and the drive means is adapted to counter rotate at least one of the combined fans and axial flow fan of the cleaning chamber relative to the other of the combined fans and axial flow fan of the cleaning chamber. The cleaning chamber may be substantially upright. The cleaning chamber may be substantially horizontal. Brief description of the drawings

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a schematic side elevational view of a cleaning section of a mechanical cane harvester having counter rotating fans mounted to an extractor hood of the harvester;

Figure 2 shows a view similar to that of figure 1 with the counter rotating fans mounted to a portion of the harvester which is positioned below a cleaning chamber of the harvester; Figure 3 shows a view similar to that of figures 1 and 2 with the counter rotating fans independently mounted; and

Figure 4 shows a view similar to figures 1-3 with the counter rotating fans mounted to a wall of the cleaning chamber; and

Figure 5 shows a view similar to figure 1 in that the counter rotating fans are mounted to an extractor hood of the harvester, however, counter rotating fans of figure 5 are driven by a mechanism which is similar to the mechanism which drives the counter rotating fans of figure 4. Best mode for carrying out the invention.

Referring to figures 1-4 a cleaning section 10 of a mechanical cane harvester generally comprises a feed section 12, cleaning chamber 14, and an extractor hood 16. The cleaning chamber 14 is essentially an upright cylindrical pipe. An upper end of the cleaning chamber 14 extends into a lower region of the extractor hood 16. A mixture of cane billets and trash is fed through the feed section 12 and across a lower end of the cleaning chamber 14. The trash is separated from the cane billets by producing an upwardly directed flow of air within the cleaning chamber 14 which is capable of drawing the less dense trash upwardly away from the cane billets toward the extractor hood 16 as the cane billets fall downwardly away from the lower end of the cleaning chamber 14. The extractor hood 16 is designed to direct the trash which is carried upwardly by the flow of air within the cleaning chamber 14 out through a discharge portion 22 of the extractor hood 16 and onto the ground.

The upwardly directed flow of air is produced by axial flow fans 18 and 20. The axial-flow fans 18 and 20 are substantially centrally positioned along the longitudinal length of the cleaning chamber 14. Figures 1-4 provide examples of different ways of mounting the axial flow fans 18 and 20. In each example the axial flow fans 18 and 20 may be driven by any appropriate means. For example, the fans 18 and 20 may be driven by hydraulic motors . Alternatively, they may be driven by chain or belt drives. Referring to figure 1 the axial- flow fans 18 and 20 are mounted to the cleaning chamber 14 via concentric shafts 24 and 26, which extend downwardly from the extractor hood 16. The shaft 26 is concentrically positioned within the shaft 24 and both shafts 24 and 26 extend from a hydraulic drive mechanism 28 which is mounted to the extractor hood 16 and positioned on top the extractor hood 16. The concentric shafts 24 and 26 pass through an opening in the extractor hood 16 and extend downwardly toward the cleaning chamber 14, longitudinal axes of the concentric shafts 24 and 26 being aligned with a longitudinal axis of the cleaning chamber 14. The axial-flow fans 18 and 20 are appropriately fitted to lower ends of shafts 24 and 26 respectively to enable counter rotation of the axial-flow fans 18 and 20 upon counter rotation of the concentric shafts 24 and 26. The spacing of the axial-flow fans 18 and 20 may be adjusted to produce maximum updraft with minimum turbulence of the upwardly directed flow of air which is produced by counter rotation of the axial-flow fans 18 and 20 within the cleaning chamber 14. Referring to figure 1 hubs 30 and 32 of the axial-flow fans 18 and 20 respectively are spaced apart by approximately 25 millimeters. A minimum distance of approximately 25 millimeters similarly separates veins of the axial-flow fans 18 and 20. However, the hubs and veins of the axial flow fans 18 and 20 do not have to be this closely positioned relative to each. For example, they could be separated by approximately 250mm.

During operation of the cleaning section 10, trash and cane billets enter via the feed section 12 and pass beneath a lower end of cleaning chamber 14, moving from a left hand side of the cleaning chamber 14 of figures 1-4 to a right hand side of the cleaning chamber 14 of figures 1-4 while also moving downwardly under gravity. Counter rotation of the axial-flow fans 18 and 20 results in an upward directed flow of air being produced within cleaning chamber 14. This upwardly directed flow of air draws the less dense trash away from the mixture of trash and sugar cane billets, upwardly through the cleaning chamber 14, into the extractor hood 16 and subsequently through the trash discharge opening 22 of the extractor hood 16 and onto the ground. The more dense sugar cane billets continue to move downwardly as they move across the lower end of the cleaning chamber 14 to be further processed by the mechanical harvester. Referring to figures 2-4, the process of separating the trash and sugar cane billets is the same. However, the counter rotating axial-flow fans 18 and 20 are mounted differently. Referring to figure 2 the axial- flow fans 18 and 20 are attached to concentric shafts 24 and 26; although, the concentric shafts 24 and 26 extend upwardly toward the axial flow fans 18 and 20 rather than downwardly toward the axial flow fan 18 and 20 as in the cleaning section 10 of figure 1. Lower ends of the concentric shafts 24 and 26 extend upwardly from a hydraulic drive mechanism 28. The hydraulic drive mechanism 28 is mounted to an arm 34, a lower end of which is mounted to the feed section 12. The arm 34 therefore extends from a left hand side of the cleaning section 10 of figure 2 toward a longitudinal axis of the cleaning chamber 14 while also moving upwardly toward a lower end of the cleaning chamber 14. Referring to figure 3, the axial-flow fans 18 and 20 are independently mounted within the cleaning chamber 14. The axial flow fan 18 is mounted to a lower end of a shaft 36 which extends downwardly from the extractor hood 16. An upper end of the shaft 36 extends downwardly from a hydraulic drive mechanism 28 and the hydraulic drive mechanism 28 is mounted on top of the extractor hood 16. The axial flow fan 20 is mounted to an upper end of a shaft 37 which extends upwardly from a position within the cleaning chamber 14. The lower end of the shaft 37 extends from another hydraulic drive mechanism 28 which is positioned centrally within the cleaning chamber 14, at a lower end of the cleaning chamber 14. The hydraulic drive mechanism 28 which is positioned at the lower end of the cleaning chamber 14 is fixed relative to the cleaning chamber 14 via an arm 38 which is the same as the arm 34 of figure 2.

Referring to figure 4, the axial-flow fans 18 and 20 are mounted to the cleaning chamber 14 via a common arm 40. One end of the arm 40 is mounted to a wall of the cleaning chamber 14 and the arm 40 extends laterally away from the wall of the cleaning chamber 14, between the axial-flow fans 18 and 20. The other end of the arm 40 is mounted to hydraulic drive mechanism 28 which is positioned between hubs of the axial-flow fans 18 and 20. The axial flow fans 18 and 20 are attached to shafts (not shown) which extend upwardly and downwardly respectively of the hydraulic drive mechanism 28. Referring to figure 5, the axial flow fans 18 and 20 are mounted respectively above and below a gearbox 44 which is substantially centrally positioned along the longitudinal axis of the cleaning chamber 14. The gearbox 44 is driven via a shaft 46 which extends downwardly toward the gearbox 44 from the extractor hood 16. The shaft 46 is driven by a hydraulic drive mechanism 28 which is mounted on top of the extractor hood 16. The longitudinal axis of the shaft 46 is substantially aligned with an axis about which axial flow fans 18 and

20 rotate. The gearbox 44 is designed to enable the axial flow fans 18 and 20 to counter rotate relative to each other at substantially the same angular velocity.

Claims

The claims defining the invention are as follows

1. A method of separating sugar cane billets and extraneous matter during harvesting of sugar cane, the method comprising the steps of: (a) providing a plurality of axial flow fans within a tubular cleaning chamber of a cane harvester; and (b) counter rotating at least one of the axial-flow fans relative to the remaining axial-flow fans to create an airflow which is adapted to draw trash from a mixture of billets and trash.

2. A method as claimed in claim 1 wherein each of the plurality of the axial-flow fans are positioned relative to adjacent axial-flow fans so that they are axially positioned relative to each other as close as possible without contacting.

3. A method as claimed in claim 1 or claim 2 wherein the plurality of axial flow fans is an even number of axial flow fans.

4. An apparatus for separation of sugar cane billets and extraneous matter during harvesting of cane, the apparatus comprising a plurality of fans, mounting means for mounting the fans axially within a tubular cleaning chamber of a cane harvester, and rotation means for rotating each of the fans, wherein the rotation means is adapted to counter rotate at least one of the plurality of fans relative to the other of the plurality of fans, while the fans are axially aligned within the cleaning chamber via the mounting means, to produce axial air flow within the cleaning chamber .

5. An apparatus as claimed in claim 4 wherein each of the plurality of fans are positioned relative to adjacent fans so that they are axially positioned relative to each other as close as possible without contacting.

6. An apparatus as claimed in claim 4 or claim 5 wherein the rotation means comprises a plurality of shafts for rotation of one or more fans and one or more drive means for rotation of the plurality of shafts.

7. An apparatus as claimed in claim 6 wherein the plurality of shafts are concentrically arranged relative to each other.

8. An apparatus as claimed in claim 6 or claim 7 wherein the mounting means is adapted for mounting the fans within the tubular cleaning chamber via the one or more drive means to either the tubular cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

9. An apparatus as claimed in claim 8 wherein one or more of the drive means includes a gearbox, the gearbox being adapted to either independently mount, via the_mounting means, to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber, or the gearbox being adapted to be mounted by way of its attachment to the remainder of its associated drive means.

10. An apparatus as claimed in claim 8 or claim 9 wherein the mounting means comprises one or more mounting members, each mounting member being adapted to mount at least one of the drive means to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

11. An apparatus as claimed in claim 10 wherein the mounting member is adapted for mounting two drive means substantially centrally along the longitudinal length of a cleaning chamber, adjacent each other, between two or more shafts which extend away from the two adjacent drive means, along the longitudinal axis of the cleaning chamber.

12. An apparatus as claimed in claim 10, wherein the mounting member is adapted for mounting one of the drive means to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

13. An apparatus as claimed in any one of claims 4-12 wherein the plurality of fans is an even number of fans and the rotation means is adapted to counter rotate half of the plurality of fans relative to the other half of the plurality of fans.

14. An apparatus as claimed in claim 13 wherein the plurality of fans comprises two fans.

15. A cane harvester for harvesting sugar cane, the cane harvester comprising a tubular cleaning chamber and a plurality of fans which are positioned axially within the cleaning chamber and adapted for rotation within the cleaning chamber to produce flow of air within the cleaning chamber which flows along the longitudinal length of the cleaning chamber in a direction substantially aligned with the longitudinal axis of the cleaning chamber wherein at least one of the fans is adapted for counter rotation relative to the other fans.

16. A cane harvester as claimed claim 15 wherein each of the plurality of fans are positioned relative to adjacent fans so that they are axially positioned relative to each other as close as possible without contacting.

17. A cane harvester as claimed in claimed 15 or claim 16 wherein rotation means comprises a plurality of shafts_for rotation of one or more fans and one or more drive means for rotation of the plurality of shafts.

18. A cane harvester as claimed in claim 17 wherein the plurality of shafts are concentrically arranged relative to each.

19. A cane harvester as claimed in claim 17 or claim 18, wherein the plurality of fans are positioned axially within the cleaning chamber via mounting means, the mounting means being adapted for mounting the fans within the cleaning chamber via the one or more drive means to either the tubular cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

20. A cane harvester as claimed in claim 19 wherein one or more of the drive means includes a gearbox, the gearbox being adapted to either independently mount, via the mounting means, to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber, or the gearbox being adapted to be mounted by way of its attachment to the remainder of its associated drive means.

21. A cane harvester as claimed in claim 19 or claim 20 wherein the mounting means comprises one or more mounting members, each mounting member being adapted to mount at least one of the drive means to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

22. A cane harvester as claimed in claim 21 wherein the mounting member is adapted for mounting two drive means substantially centrally along the longitudinal length of a cleaning chamber, adjacent each other, between two or more shafts which extend away from the_two adjacent drive means, along the longitudinal axis of the cleaning chamber.

23. A cane harvester as claimed in claim 21 wherein the mounting member is adapted for mounting one of the drive means to either the cleaning chamber or a portion of the a cane harvester which is proximal the cleaning chamber.

24. A cane harvester as claimed in anyone of claims 15- 23 wherein the plurality of fans is an even number of fans and the rotation means is adapted to counter rotate half of the plurality of fans relative to the other half of the plurality of fans.

25. A cane harvester as claimed in claim 24 wherein the plurality of fans comprises two fans.

26. A system for separation of sugar cane billets and extraneous matter during the harvesting of sugar cane, the system comprising: a plurality of fans, mounting means for mounting the fans axially within a tubular cleaning chamber of a cane harvester, and rotation means for rotating each of the fans, wherein the rotation means is adapted to counter rotate at least one of the plurality of fans relative to the other of the plurality of fans, while the fans are axially aligned within the cleaning chamber via the mounting means, to produce axial air flow within the cleaning chamber.

27. A system as claimed 26 wherein each of the plurality of fans are positioned relative to adjacent fans so that they are axially positioned relative to each other as close as possible without contacting.

28. A system as claimed in claim 26 or claim 27 wherein the rotation means comprises a plurality of shafts for rotation of one or more fans and one or more drive means for rotation of the plurality of shafts.

29. A system as claimed in claim 28 wherein the plurality of shafts are concentrically arranged relative to each other.

30. A system as claimed in claim 28 or claim 29 wherein the mounting means is adapted for mounting the fans within the tubular cleaning chamber via the one or more drive means to either the tubular cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

31. An system as claimed in claim 30 wherein one or more of the drive means includes a gearbox, the gearbox being adapted to either independently mount, via the mounting means, to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber, or the gearbox being adapted to be mounted by way of its attachment to the remainder of its associated drive means.

32. A system as claimed in claim 30 or claim 31 wherein the mounting means comprises one or more mounting members, each mounting member being adapted to mount at least one of the drive means to either the cleaning chamber or a portion of cane harvester which is proximal the cleaning chamber.

33. A system as claimed in claim 32 wherein the mounting member is adapted for mounting two drive means substantially centrally along the longitudinal length of a cleaning chamber, adjacent each other, between two or more shafts which extend away from the two adjacent drive means, along the longitudinal axis of the cleaning chamber.

34. A system as claimed in claim 32, wherein the mounting member is adapted for mounting one of the drive means to either the cleaning chamber or a portion of a cane harvester which is proximal the cleaning chamber.

35. A system as claimed in any one of claims 26-34 wherein the plurality of fans is an even number of fans and the rotation means is adapted to counter rotate half of the plurality of fans relative to the other half of the plurality of fans .

36 A system as claimed in claim 35 wherein the plurality of fans comprises two fans.

37. An apparatus for separation of sugar cane billet and extraneous matter during harvesting of cane, the apparatus comprising a plurality of fans, a plurality of shafts for axially rotating the fans, and drive means for rotating the shafts wherein the plurality of shafts are substantially axially aligned and axially attached to one or more of the fans, and the drive means is adapted to rotate the plurality of shafts so that at least one of the plurality of fans counter rotates relative to the other fans.

38. An apparatus as claimed in claim 37 wherein the plurality of shafts are concentrically arranged relative to each other.

39. An apparatus as claimed in claim 37 or claim 38 wherein the apparatus is adapted for location within a tubular cleaning chamber of a cane harvester, counter rotation of the fans producing flow of air within the cleaning chamber which is adapted to draw extraneous matter through the cleaning chamber in a direction substantially aligned with a longitudinal axis of the cleaning chamber.

40. An apparatus as claimed in claim 38 or claim 39 wherein the apparatus comprises 2 concentric shafts, each shaft axially attaching to half of the plurality of fans, and the fans attached to each shaft being spaced predetermined distances along the longitudinal length of each shaft.

41. An apparatus as claimed in any one of claims 37-40 wherein the plurality of fans is an even number of fans.

42. An apparatus for the separation of sugar cane billets and extraneous matter during the harvesting of cane comprising one or more fans, one or more shafts for rotating the fans, drive means for rotating the shafts, and mounting means for mounting the fans within a tubular cleaning chamber of a cane harvester, and the cane harvester including an axial flow fan which has its veins transversely orientated relative to a longitudinal axis of the cleaning chamber wherein the mounting means is adapted to axially align the fans with the axial flow fan and the drive means is adapted to for counter rotate at least one of the combined fans and axial flow fan of the cleaning chamber relative to the other of the combined fans and axial flow fan of the cleaning chamber.

43. A system for separation of sugar cane billets and extraneous matter during the harvesting of sugar cane, the system comprising: one or more fans, drive means for rotating the shafts, and mounting means for mounting the fans within a substantially tubular cleaning chamber of a cane harvester, the cane harvester including an axial flow fan are which has its veins transversely orientated relative to a longitudinal axis of the cleaning chamber wherein the mounting means is adapted to_axially align the fans with the axial flow fan and the drive means is adapted to counter rotate of at least one of the combined fans and axial flow fan of the cleaning chamber relative to the other of the combined fans and axial flow fan of the cleaning chamber.