PRE-PROCESSING OF SUGAR CANE

Abstract

A system for infield collection of substantially whole cane and delivering that cane to a mill via a trash separator and a washer. A harvester collects whole cane and throws billeted cane along with trash into an infield transporter which then transports this to a centralised trash separator. The trash separator may service any number of infield transporters and may be located at a mill or a centralised location so that output from the trash separator may pass on to a conveyor. Billets are then fed to a washer. The washing liquid from downstream process may be used in the washer. Mud and dirt is removed from the billets in return liquid which then passes to a mud removal unit. This juice is returned to the downstream process. Wash liquid may also be collected via an outlet conveyor. A modular harvester, a trash separator and a washer are also described.

Claims

1. A method for preparing sugar cane for further processing comprising the steps of: a. mechanically cutting and collecting a batch of substantially whole cane infield; b. delivering the batch of cane from the field to a trash separator; and subsequently separating trash from cane in the batch; and c. delivering the trash separated cane for further processing.

2. The method of claim 1 further involving the step of washing the trash separated cane.

3. A system for pre-mill cane processing by infield whole cane harvesting using a whole cane harvester to prepare a batch of substantially whole cane; a trash separator for separation of trash to produce trash separated cane and a washer used to wash the trash separated cane prior to milling.

4. A cane harvester for mechanically cutting and collecting a batch of cane infield for an infield cane transporter, the harvester comprises a drive unit, a feed system and chopper, characterised in that downstream of the chopper is a thrower such that substantially whole cane is harvested and delivered to the infield transporter.

5. A cane harvester according to claim 4 wherein the feed system is an integrated modular feed system for removal and repair or for changing operative row width.

6. A cane harvester according to claim 4 wherein the feed system includes inclined cane base cutters with a forward downward angle of attack to cut close to the ground.

7. A cane harvester according to claim 4 wherein the chopper is a billeter and the thrower is a cane billet thrower to deliver cane billets and trash to an adjacent infield transporter.

8. A cane harvester according to claim 4 wherein the feed system is a floating front feed system for undulating terrain.

9. A cane harvester according to claim 4 wherein the feed system is a floating front feed system for undulating terrain, the feed system is made floating by a counter weight or force for the feed system.

10. A cane harvester according to claim 4 wherein the feed system is a floating front feed system for undulating terrain, the feed system is made floating by provision of upward lift to offset load on the feed system.

11. A cane harvester according to claim 4 wherein the feed system is a floating front feed system for undulating terrain, the feed system is made floating by provision of upward lift to offset load on the feed system, the feed system comprising two row feeders, each row feeder floating independently. In one preferred form an adjustable length bias spring is employed and the feed system is pivotally mounted to the harvester.

12. A cane harvester according to claim 4 wherein the feed system is a floating front feed system for undulating terrain, the feed system is made floating by provision of upward lift to offset load on the feed system, the feed system comprising two row feeders, each row feeder floating independently and being pivotally mounted to the harvester.

13. A cane harvester according to claim 4 having a front end of a carriage, the feed system extending from the front end, the feed system being adapted for elevation independently of the front end, the feed system employing a forward section upstream of base cutter blades, the base cutter blessed having an angle of attack for close to ground cutting, the forward section being floating relative to the angle of attack of the cutter blades.

14. A cane harvester according to claim 4 having a front end of a carriage, the feed system extending from the front end, the feed system being adapted for elevation independently of the front end, the feed system employing a forward section upstream of base cutter blades, the base cutter blessed having an angle of attack for close to ground cutting, the forward section being floating for undulating ground relative to the angle of attack of the cutter blades, the forward section is made floating by reason of sets of spaced linkages guiding the front section between limits.

15. A cane harvester according to claim 4 having a front end of a carriage, the feed system extending from the front end, the feed system being adapted for elevation independently of the front end, the feed system employing a forward section upstream of base cutter blades, the base cutter blessed having an angle of attack for close to ground cutting, the forward section being floating for undulating ground relative to the angle of attack of the cutter blades, the forward section is made floating by reason of sets of spaced linkages guiding the front section between limits provided by mating curved sections, the linkages connect to the curved sections which curved sections abut at upper and lower range of relative movement between the forward section and the cane base cutter blades.

16. A cane harvester according to claim 4 wherein the feed system includes inclined cane base cutters with a forward downward angle of attack to cut close to the ground, the blades being set at an inclined angle of attack with each blade formation generally following the edge of an inverted shallow dome configuration.

17. A cane harvester according to claim 4 wherein in a cane harvester, the harvester has a carriage comprising a prime mover and a chassis, and a transportation footprint, the footprint being within the boundaries of a shipping container.

18. A cane harvester according to claim 4 wherein the chopper is a bilieter having interdigitated spaced billet cutters having radially extending circumferentially spaced blades so dimensioned and arranged for lifting and passing stones of up to about 200 mm.

19. A cane harvester according to claim 4 wherein there is provided billet chopper replacement blades adapted to slide out sideways for replacement.

20. A cane harvester according to claim 4 wherein the feed system comprises a shortened billeting and feed assembly comprising inclined feed conveyors, base chopper blades, a rotary conveyor, and billet cutters leading onto a billet thrower.

21. A cane harvester according to claim 4 wherein the harvester has a modular setup on a prime mover and carriage, the feed system being a removable module and the thrower being a removable module so that the prime mover and carriage may be repurposed for other uses by removing the modules.

22. A cane harvester according to claim 4 wherein the feed system is an integrated modular feed system with interchangeable modules for changing operative row width.

23. A cane harvester according to claim 4 for cutting two rows, each row having a row feeder sharing a common billet cutter.

24. A cane harvester according to claim 4 for cutting two rows, each row having a row feeder sharing a common billet cutter, and flow paths tapering inwardly to the billet cutter.

25. A trash separator or trash remover when used in the method of claim 1 having an input conveyor for billets and trash which delivers the billets and trash through an entrance onto a curved grate through which air is driven to remove trash, the conveyor being inclined to the axial line of the grate.

26. A cane washer when used in the method of claim 2 having a washer tank having a billet inlet and billet outlet, an agitator/conveyor within the tank, a billet elevator communicating with the outlet, a liquid entry to the tank from downstream process and a return liquid collector below the elevator to return liquid to downstream process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order that the present invention, aspects and improvements may be more readily understood and put into practical effect reference will now be made to the accompanying drawings which illustrate preferred embodiments and wherein:

[0036] FIG. 1 is an overall schematic block diagram illustrating general application of the present invention in a preferred form;

[0037] FIG. 2 is a drawing illustrating modular aspects of a typical harvester;

[0038] FIG. 3 is a drawing illustrating modular aspect of a two row harvester with independent modular feeders;

[0039] FIGS. 4 and 5 are end and side views of the harvester of FIG. 3;

[0040] FIGS. 6A through 6B are drawings illustrating the adjustable spring bias and raising features of the prime mover attached to the modular row feeder;

[0041] FIGS. 7A and 7B illustrate further details of that arrangement;

[0042] FIGS. 8A through 8C are drawings illustrating how cane is cut and billeted in the harvester according to the present invention;

[0043] FIG. 9 is a drawing of a billet cutter capable of passing quite large stones;

[0044] FIG. 10 is an exploded view of a trash separator/remover;

[0045] FIGS. 11A through 11D are further drawings of a trash remover according to the preferred form;

[0046] FIGS. 12A through 12D illustrate operation of part of the trash remover of the preceding figures;

[0047] FIGS. 13A through 13C are views illustrating a billet conveyor that feeds billets by gravity through the trash remover of the preceding figures;

[0048] FIG. 14 is an exploded view illustrating a washer unit according to the present invention;

[0049] FIGS. 15A through 15D illustrate different views of the billet washer of the preceding figures;

[0050] FIGS. 16A through 16B are drawings of an end view of a typical billet washer and a section through A-A of FIG. 16A;

[0051] FIGS. 17A through 17D are drawings illustrating a preferred relationship between the front of the feed and billeting unit and its cutter blades; and

[0052] FIGS. 18A and 18B are top and side schematics of a variation employing a single module for two rows.

METHOD OF PERFORMANCE

[0053] Referring to the drawings and initially to FIG. 1 there is illustrated an overall system 10 for infield collection of whole cane and delivering that cane to a mill via a trash separator and a washer. In the embodiment illustrated a harvester 11 collects whole cane and throws billeted cane into an infield transporter 12 which then transports this to a centralised trash separator 13. Now it will be appreciated that this trash separator may service any number of infield transporters and may be located at the mill or at another centralised location so that output from the trash separator may pass on to a conveyor 14. Billets 15 are then fed to a washer 16 which in this embodiment is configured so that the washer is upstream of a mill. This means washing liquid from downstream process from say mill 2 in milling tandem may be used in the washer. This liquid enters the washer at 17. Mud and dirt is removed from the billets in return liquid at 18 which then passes to a mud removal unit 19 of conventional form. This juice is returned to the downstream process along line 20. It will be appreciated that since whole cane is being transported to a dedicated trash separator at 13 that there is very little loss in terms of juice carrying cane. The billets are moved on to the mill at 21. They will move to the first stage mill usually via a conveyor. Wash liquid may also be collected via an outlet conveyor from the washer.

[0054] Referring now to FIG. 2 there is illustrated one example of a modular harvester 11 comprising a drive unit 22, a removable billet thrower and chute 23 and 24 and a feed and billeter module 25 in this case being a two row unit which may be inserted under the chassis 26 and secured by pivot couplings 27 and 28 to corresponding mounts 29 and 30.

[0055] FIG. 3 illustrates single row modules 31 and 32 and like numerals illustrate like features it being appreciated that in this embodiment the single row feed and billeting units 31 and 32 may pivot independently of each other. This is illustrated in FIG. 4 where the module 31 is shown slightly higher in position relative to the module 32. The thrower 23 is shown in its operative position with the chute 24 delivering billets to the left hand side of the harvester.

[0056] The assemblies 25, 31 and 32 are arranged to float and follow the ground surface over which the harvester moves and to this end each of the assemblies is biased into floating contact with the ground by reason of one or more spring assemblies 33 which are more clearly illustrated in FIG. 6B. A wire rope 34 connects to an end plate 35 via a threaded adjuster 36. An adjustment nut 37 is used to regulate, the length of the spring 38. It will be appreciated that there is some adjustment of the spring in order to regulate the floatability of the feeders. By reason of the spring there will be a damping and shock absorption action that will retain the entry of the feeding to the harvester at the front due to the connection of the wire rope 34 relative to the pivot connections at 29 and 30.

[0057] Quite independently of the spring assembly 33 are hydraulic ram assemblies 39, 40, 41 and 42 (part of which is shown) and these are used to elevate the feed units well away from the ground for transportation, servicing or for changing front wheels etc.

[0058] Referring now to FIGS. 8A through 8C operation of the harvester will be illustrated relative to cane shown at 42. As can be seen in 8B and 8C hydraulically driven feed augers shown generally at 43 lead cane along the section aligned with B-B as depicted in FIG. 8C. A blade 44 will cut any overlapping leaves between the two rows and then a paddle wheel 45 will force the cane to an angle of about 90° relative to inclined cutter blades 46. This and the angle of attack of the blades which will cut off the cane very close to the ground therefore maximising the length of cane above the ground to be retrieved. The cut end is fed into the billet cutter feeder assembly at 47 thus effectively inverting the cane stalk as it is fed into the billet cutters 48. The billets cut billets fall into the thrower 23 where they are ejected via the chute 24 into an infield transporter (not shown).

[0059] It will be appreciated that since there are no extractors or blowers the the trash is also fed along with the billets through the chute 24 into an infield cane transporter. The harvester can be made much shorter than conventional as there is a shorter travel of the cane through the harvester into the thrower. This permits containerisation of the harvester.

[0060] Since the cutter blades at 46 are inclined and are directed ostensibly at the very bottom of the cane stalks to cut them off, then there is a possibility that rocks and other debris might enter into the billet conveyor section, Consequently, the conveyor section also has rubberised fingers in, the paddle wheel at 49. The cutter blades at 48 as illustrated in FIG. 9 have their axles spaced so that the barrels 50 carrying the cutter blades 52 and the blades are so dimensioned and arranged that they may pass rocks up to, in this example, 211 mm with one such rock being illustrated by the circle at 53.

[0061] As shown in FIG. 1 once the cane has been harvested by the harvester 11, located in the infield transporter it is then sent to a trash separator or trash remover 13 and an example of a trash remover 13 is shown in exploded format in FIG. 10 with further details and operation being shown FIGS. 11A through 130. The components of the separator include intermediate ducting 54 which has a gravitational input and an output at 55 for billets. These fail on to a conveyor 14.

[0062] In this case there is an input conveyor for billets and trash at 56 which delivers the billets and trash through an entrance to the ducting 54 at 57. Inside the ducting is a curved separator grate 58 which exposes the lighter trash to a regulated aft flow. The grate is carded by grate support plates 59, 60 and 61. Blower fans at 63 draw air through inlet at 64. This arrangement of fans driven at an appropriate flow rate will provide removal of trash as billets progressively fall down and along the grate, travel around the curvature of the grate by gravity. The trash is blown off for collection in the cyclone at 65 and subsequent shredding.

[0063] The relative position of the conveyor 56 is shown in plan view in FIG. 11A and as can be seen it is inclined to the axial line of the ducting 54 and also inclined to the direction of the grate 58 with the relative arrangement of these shown in FIG. 130. The underside of the conveyor as shown in FIG. 13A showing the gravitational exit opening at 67 for the billets being carried by the conveyor. This exit opening locates and traverses the curved grate 58 as clearly depicted in FIG. 130. This opening relative to the billet conveyor effectively widens over the grate and allows for even flow of the billets across the full width of the grate 58. This even flow means that there is an even distribution of clearing aft flow to blow trash away from the cane billets. This air flow is typically around 11 metres per second. This is illustrated with the trash particles shown at 66 in FIGS. 12A through 12D.

[0064] As further is shown in FIG. 1 as the trash removed billets leave the trash separator they move on to a conveyor 14. They are conveyed to a washer 16 details of which are shown in exploded view in FIG. 14 and through FIG. 16B. A washer tank 68 holds a mixer, agitator 69, with helical mounted blades 70 so that cane falls into one end of the tank 68 where it is propelled and agitated toward the other end. Here the billets are pulled onto an elevator assembly 71 with the bottom of the elevator travelling through the end at 72.

[0065] Relatively dean low brix juice from the number 2 mill in a milling tandem is heated to about 100° C. and is used in the washer entering at 73. The agitator speed is about 6 m/s to break up clods of dirt in cane roots. Relatively dirty return juice flows through a perforated plate 74 in the elevator assembly in collector tray 75 and also through drain 77 where it is returned back to process.

[0066] Referring now to FIGS. 17A through 17D there is illustrated another preferred embodiment of a front end section 78 of a feed and billeting module, similar to the module 25. In this case the module has its cane lead-in conveyors 79 mounted to float by reason of sets of spaced linkages 80 and 81 (one set being shown in the drawings).

[0067] The linkages are shown connected to mating curved sections 82 and 83 which abut at upper and lower range of relative movement between the front and the cane base cutter blades 85 (FIGS. 17C and 17D). A typical range is illustrated in the drawings in mm at 30 mm (mid range), 88 mm (lower range) and 95 mm (upper range).

[0068] Thus the front 85 may cater for different row variations including furrows or hilled rows.

[0069] The blade sets 85 in this embodiment are forwardly inclined but as may be discerned from the side views of 17A, 17C and 17D the blade formation generally follows the edge of an inverted shallow dome configuration or equivalent.

[0070] Whilst the above has been given by way of illustrative example many variations and modifications will be apparent to those skilled in the art without departing from the broad ambit and scope of the invention as set out in the appended claims. For example, FIGS. 18A and 18B illustrate a simplified schematic of a variation where rather than each row having its own module this is a two row module and chassis assembly 86, in this case for a 1.8 m row spacing, the cutters 85 are used, and the basic feed is the same but the rows are fed into a common billet cutter 48 that they share. The chassis has a single front wheel 87 to aid turning. The cane flow path is indicated by the lines 88 and 89 which then come together into a single stream at 90. The billet thrower and chute 23 and 24 of the previous embodiments (not shown here) is also fitted as a module. The feed arrangement is shown in part in FIGS. 18A and 18B at 91 and 92 so there are separate feed systems for each row but these have an inward taper to match lines 88 and 89. The feed systems themselves may be conventional or may be configured as previously described in terms of each feed stage, although there will usually be additional feed rollers at 91 as there may be a slightly longer path to the billeter. The feed systems are removable as a pivoting module as before and they also float as before. The taper ensures that the chassis and the parts making up the harvester may still all be fitted into a 40 foot shipping container. The skilled person will readily understand all the optional variations.

[0071] It will be further appreciated that the main objective of one form of the invention is to collect cane juice that is inadvertently left behind by the prior art harvesters when trying to separate cane stalks and leave trash, so whole cane as referred to here is not to be taken literally but means substantially whole cane as captured by the present invention compared to the prior art, since inevitably some of the cane leaves and stalks will be left infield no matter how efficient a process is. Whole cane effectively herein means greater efficiency overall rather than literally whole cane plants.