Development of a single drum chopper concept for a sugarcane harvester

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(1)This file is part of the following reference:. Barnes, Matthew Gavin (2008) Development of a single drum chopper concept for a sugarcane harvester. Masters (Research) thesis, James Cook University. Access to this file is available from: http://eprints.jcu.edu.au/17529.

(2) Development of a Single Drum Chopper Concept for a Sugarcane Harvester. Thesis submitted by. Matthew Gavin Barnes Bachelor of Engineering (Mechanical) with Honours Jalnes Cook University, Townsville. in December 2008. for the degree of Master of Engineering Science in the School of Engineering (Mechanical Engineering) James Cook University.

(3) 11. Statement of Access. I,. t]1e. undersigned, the author of this thesis, understand that James Cook University will. tnake it available for use within the University Library and, by tnicfofihn or other lneans, allow access to users in other approved libraries. All users consulting with this thesis will have to sign the following statelnent:. In consulting this thesis I agree not to copy or closely paraphrase it in lvlzole or ill part Jvitlzout Jvritten consent of the author; alld to nlake proper public lvritten acknowledgenlelltfor any assistance lvllich I have obtained/ronl it.. Beyond this, I do not wish to place any restriction on access to this thesis.. Matthew Gavin Barnes. I. 7. I.

(4) 111. Sources Declaration. I declare that this thesis is Iny own work and has not been submitted in any forln for another degree or diplolna at any university or other institution of teltialy education. Infoflnation derived frOln the published or unpublished work of others has been acknowledge in the text and a list of references is ,given.. Matthew Gavin Barnes.

(5) tv. Acknowledgements The author ,vishes to express his appreciation to the following persons for the valuable help given to me during this study: My supervisor; Professor Jeffrey Loughran, of JaJnes Cook University, for your guidance, support and motivation throughout the course of this research. Doctor Bruce Lan1b, of New South Wales Sugar Cooperative, for creating this project and for your SUpp01t throughout the course of this work. Rockfield Technologies for the detailed design and construction of the prototype chopper rig. The Jalnes Cook University workshop staff, for your assistance with the installation and n1aintenance of the prototype chopper rig. Mr. Catn Whiteing, ofBSESLitnited, for your assistance with the prototype testing. The Sugar Research and Developme11t Corporation for the sponsorship of this project. My fatnily for their ongoing support and encouragelnent throughout n1Y studies..

(6) v. Abstract A global push towards reneyvable energy has seen the birth of cogeneration in Australian sugar ll1ills.. To nlaxi111ise the all10unt of energy extracted froln the 111aterial, whole crop. harvesting has been introduced, where a higher proportion of total bio111ass is sent to the 111 ill.. The adverse affect of this is a significant reduction in bulk density of the harvested. ]l1aterial.. Transport costs to harvester Ol'FnerS and 111illers significantl)l increase as bin. weights are reduced, and therefore there is a case for developing a harvester chopper systen1 l'vhich ll1aintains bin weight as the anl0unt of trash sent to the lnill increases. The single knife slicing ofsugarcane stalks against a stationary anvil l'FaS investigated in this study and fron1 the findings a single dru]l1 chopper syste111 was developed. An explicit finite ele]l1ent ]l1odel of the proposed concept was constructed for assess]nent of billet trajectories through the syste 111. Positive results fro111 these lnodels gave confidence for the construction of a prototype for experiJnental asseSSll1ent of the perforlnance of the systell1. Cane and juice losses and ,billet quality l'Fere lneasuredfor a range ofoperational conditions which included varying the chopper drU111 speed, pour rate and chopper drU111 ge0111etlY.. The cutting. process 117as captured by high speed photography for analysis into the causes of da111age and losses. Speeding up the chopper dru111 and therefore shortening the billet length proved to have the 1110s1 detriJnental effect on syste111 peliornlance, l'vhere a reduction in the target billet length fro111 200. 111111. to 100 1111'11 resulted in over three tiJnes the overall losses. An. increase in pour rate did not have a significant effect on losses or billet quality. The high speedjootage provided invaluable insight into the behaviour ojthe stalks as they were cut by the single drull1 syste111.. For the set oj trial conditions 1110St closely representing those. previously done l'vith differential choppers, the single dru111 S)lsten1 produced siJnilar efficiency results. H01vever, the advantages ofthis syste111 are ]110st pro111inent in yvhole crop harvesting whel:e shorter billets are required to ]J1aintain bin ytleights..

(7) VI. Contents ii. Statement of access Soul·ces declaration. ~. iii. Acknowledgements. iv. Abstract. v. Contents. vi. Tables. ix. Figures. xii. Symbols. xiv. 1. Introduction. 1. 1.1. Backgroulld and motivatioIl. 2. 1.2. Reseal·cll context. 1.3. Ailn. 3. 1.4. Scope. 3. 1.5. Tllesis outliIle. 4. ,. :. 3. 2. Literature Review. 6. 2.1. The nlechanical sugarcane harvester. 7. 2.1.1.. The history of chopper systelns in sugarcane harvesters. 9. 2.1.2.. Cll0pper losses. 2.2. ~. Chopper systelns used in silnilar industries. 11 13. ~. 2.2.1.. The forage harvester chopper systelTI. 13. 2.2.2.. The use of forage harvesters for cutting sugarcaIle. 17. 2.3. The physical structure of sugarcane. 18. 2.4. The nlechanical propeliies of sugarcane. 20. 2.5. Cuttil1g sllgaI"CaIle. 22. 2.6. Predicting the bulk density of a cane and trash Inixture. 23. 2.7. Conclusions froln the literature review. 26. 3. Laboratory billeting experiments. 27. 3.1. Aims. 28. 3.2. Appal"atus. 28. Instrulnentation and recording devices. 30. Description of the experilnent. 30. Vat·iables. 30. 3.2.1. 3.3 3.3.1..

(8) VB. 3.3.2.. Experinlental procedure. 32. 3.3.3.. Expel·imel1tal design. 33. 3.3.4.. Quantitative experin1ental outputs. 35. Results. 35. 3.4.1.. Cane and juice losses. 35. 3.4.2.. High speed photography. 38. DiscusS~011. 39. 3.5.1.. Descriptive lnodel of the Inechanis111S present during the cut.. 39. 3.5.2.. Ilnplicatiol1s to the design of the chopper systenl. 40. Conclusions from the laboratory billeting experinlents. 40. 3.4. 3.5. 3.6. 4. Development of the single drum chopper concept. 41. 4.1. Ailns. 42. 4.2. Systeln requirements. 42. 4.3. COlnponent conceptualisation .~. 42. 4.3.1.. DI·um. 43. 4.3.2.. Knife. 45. 4.3.3.. Sllear bar. 46. 4.3.4.. Deflectol· plate. 47. 4.3.5.. Shal"peni11g systeln. 47. Conclusions from the concept design. 47. 4.4. 5. Dynamic modelling. 48. 5.1. Aims. 49. 5.2. Finite elelnent 1110delIing·. 49. 5.3. Description of the experiInent. 49. 5.3.1.. Val·iables. 49. 5.3.2.. Expel"ilnelltal design. 50. Model desigll. 51. 5.4.1.. Ge·olnetly. 51. 5.4.2.. Matel"ial propeliies. 53. 5.4.3.. Mesh. 53. 5.4.4.. Loads. 54. 5.4.5.. COl1stl·aillts. 55. 5.4.6.. COlltrol data. 55. 5.4.7.. Element deactivation. 56. 5.4.8.. Analysis. 56. 5.4.

(9) VIlI. 5.4.9.. Post-processor. 56. 5.5. Results and discussioll. 57. 5.6. Conclusions frOITI the dynamic ITIodelling. 60. 6. Protot)rpe testing. 61. 6.1. AiIl1S. 62. 6.2. AppaI·atus. 62. Instrunlentation and recording devices. 67. Description of the experiment. 68. 6.3.1.. Variables. 68. 6.3.2.. ExpeI·iITIental pI·ocedure. 72. 6.3.3.. ExperiInentaI desigIl. 73. 6.3.4.. Quantitative experilnental outputs. 74. Results. 77. 6.4.1.. Total cane and juice losses. 78. 6.4.2.. Cane and juice loss per cut per metre. 80. 6.4.3.. Billet quality. 83. 6.4.4.. Billet length distribution. 86. 6.4.5.. High speed footage of the cutting process. 87. 6.4.6.. M:atel·ial trajectol..y. 89. 6.5. ·ExpeI"iIneIltal el..rOl·s. 91. 6.6. Discussiol1. 92. 6.6.1.. Causes of stalk dalnage. 92. 6.6.2.. Conlparisons to current chopper systelns. 6.2.1. 6.3. 6.4. 6.7. COl1clusions froln the prototype testing. ~. 97 _.. ~. 7. Conclusions. 98. 99. 7.1. Outcolnes. 100. 7.2. RecoInnlendations for further developInenfofthe chopper concept. 101. References. 103.

(10) IX. Tables Table 1. Harvester production data (Jakeway, 2003). 17. Table 2. Mechanical properties of sugarcane (Keenliside, 1985). 21. Table 3. Levels selected for each independent variable. 31. Table 4. Experilnental plan for the laboratory experilnents. 34. Table 5. Analysis of variance for lnass loss under the independent input variables. 37. Table 6. COlnparison anlongst anvil angle levels for which significantly affected lnass loss. 37. Table 7. Levels selected for each independent variable. 50. Table 8. Target billet lengths and cOl1'esponding chopper drum speeds used in the lTIodellillg. 50. Table 9. Finite elelnent lTIodelling plan. 51. Table 10. Material propeliies: linear elastic paranleters and density. 53. Table 11. Global contact properties. 55. Table 12. Billet velocities upon contact with extraction chalnber wall (lll/s). 60. Table 13. Levels selected for each independent variable. 69. Table 14. Pour Rates and Corresponding Target Bundle Weights. 70. Table 15. Target billet lellgths and corresponding chopper druln speeds used in the testing ........................................................................................................................... 71. Table 16. Prototype testing experilnental plan. Table 17. Quantitative experiJnental results. Table 18. Analysis of variance for total lTIaSS loss under druln speed and pour rate factors. ! •••••••••••••••••••••••••••••••••••••••••••••••••••. 74 77. ........................................................................................................................... 79. Table 19. COlnparisons amongst levels for chopper drulli speed on lTIaSS loss. Table 20. Analysis of variance for lnass loss per cut under drUlTI speed and pour rate factol s 4. Table 21. 82. COlnparisons alnongst levels for chopper drum speed on lnass loss per cut per lnetre. Table 22. 80. 82. ANOVA for percentage of sound billets under druln speed and pour rate factors ........................................................................................................................... 84. Table 23. ANOVA for percentage of dalnaged billets under druln speed and pour rate facto1 s 4. 84.

(11) x. Table 24. ANOVA for percentage of tTIutilated billets under drutn speed and pour rate factot~s. Table 25. 84. CotTIparisons atTIongst levels for chopper drUtll speed on percentage of sound billets. Table 26. 85. C0111parisons atTIongst levels for chopper drutTI speed on percentage of lnutilated ,billets. ~. 85.

(12) Xl. Figures Figure 1. Most recent lllodel John Deere track driven sugarcane chopper harvester. Figure 2. Fundalllehtal cOlnponents of a lllodern ll1echanical sugarcane harvester (BSES, 2002). 7. 8. Figure 3. Rotary pinch chop systelll configurations (Hockings and Davis, 1999). 11. Figure 4. Chopper systeln in a 1998 lnodel CatlleCa harvester. 11. Figure 5. Chopper test rig used in the BSES trials (Backings and Davis, 1999). 12. Figure 6. Schen1atic of a Claas Jaguar 830 forage harvester chopper drun1 (Claas, 2002). ........................................................................................................................... 15 Figure 7. Schelnatic of a Claas Jaguar 830 forage harvester shear bar and pivot asselnbly. 15. (Claas, 2002) Figure 8. Schetnatic of a Claas Jaguar 830 forage harvester sharpening stone and holder asselnbly (Claas, 2002). 16. Figure 9. Claas Jaguar 830 forage harvester chopper knife. 16. Figure 10. Mature crop of sugarcane prior to harvest. 18. Figure 11. Cross section through a sugarcane stalk inter-node.. 1, EpiderJnis; 2, thick-. walled cells forming the rind; ~'3&4, vascular bundles of different sizes; 5, sclerenchytna; 6, pith tissue. (Van Dillewijn, 1952). 19. Figure 12. Typical stress-strain curve for sugarcane in"bending (Keenliside, 1985). 21. Figure 13. Behaviour of 6n10thy grass during cutting with knife and counter-shear (PeI SS0t1, 1987). 22. 4. Figure 14. Screenshot of (a) input panel, and (b) results panel for trash layer calculator (Lewis, 2006). 24. Figure 15. Predicted bin weights for 200 mn1 billets. 24. Figure 16. Predicted bin weights for 150 tTItTI billets. Figure 17. Predicted bin weights for 100 n1m billets. 25. Figure 18. Laboratoly cutting experilnent apparatus. 29. Figure 19. Anvil fratne showing the Inounts for the different angle settings. 29. Figure 20. Schetnatic of the cutting process studied in this set of experilnents. 30. Figure 21. Cutting edge width of the new and blunt knife. 32. Figure 22a The effect of each variable on the Inean value of lnass loss. 376. ,.~. 25. Figure 22b The effect of each variable on the percelltage of cane and juice loss per cut per 111etre of stalk. 37.

(13) XlI. Figure 23. High speed photography in1ages showing billet end dan1age caused by the cuttil1g pI~ocess. 38. Figure 24. Geol1letric restraints on a sugarcane harvester. 43. Figure 25. Chopper drUlTI geOlTIetry delllonstrating replaceable inner curves. 44. Figure 26. Kllife end pl·ofile. 45. Figure 27. Knife l'ake. 46. Figure 28. Deflectol~. 47. Figure 29. Geometry of the dynalnic model built in ELFEN. 52. Figure 30. Three drunI cutting arin profiles: (l)-D 1; (2)-D2; (3)-D3. 52. Figure 31. Mesh applied to the Inodel geolnetry. 54. Figure 32. Mesh appljed to the drUln cUttil1g arnl and close-up of knife nIesh. 54. Figure 33. Billet trajectory results for the fast druln speed (438 rpIn). 57. Figure 34. Billet trajectoly results for the Illediun1 drulli speed (292 rpm). 58. Figure 35. Billet trajectoly result~ for the slow druln speed (219 rpIn). 58. Figure 36. Desired location of billet contact on extraction chalnber back wall. 59. Figure 37. Geolnetric lTIodel and photograph of the prototype chopper systeln test rig. 63. Figure 38. PI'ototype cllopper drull1. 63. Figure 39. Replaceable inner druln curve plates (three different geolnetries). 64. Figure 40. Test rig sllear bar and pivot.. 64. Figure 41. Test rig electric lnotor, gearbox, spider coupling and variable speed control. 65. Figure 42. Test rig reduced width feed roller and cradle. Figure 43. Test r'ig feed train. 66. Figure 44. Test rig hydraulic roller lllotors aneJ power pack. 67. Figure 45. :Harvester separation chan1ber and test rig,replicate. 67. Figure 46. Cut out in the side of the ATR wall alld high speed calnera and halogen light. plate geolnetly. eo. 65. setup. 68. Figure 47. Large Bundle (300 t/hr equivalent). 72. Figure 48. SanIple after being sorted into billet qualiD'~categories. 76. Figure 49. The'effect of chopper druIll speed on the lnean value of total Inass loss. 78. Figure 50. The effect of pour rate on the lnean value oftotallnass loss. 79. Figure 51. The effect of chopper druln speed on lnean lnass loss per cut.. 81. Figure 52. The effect of pour rate on lnean mass loss per cut per lnetre. 81. Figure 53. The effect of druln speed and pour rate on billet quality (data Ineans). 83. Figure 54. Histograllls of the average billet length distribution for each target billet length ........................................................................................................................... 86. Figure 55. Still itnages of the high speed footage taken for test number 11. 89.

(14) XUI. Figure 56. Still ilnages of the high speed footage of the billet trajectolY for a target billet length of200 InITI (N drum == 438 rpln). 90. Figure 57. Still ilTIage of the lnaterial trajectory recorded by the normal speed calnera. 91. Figure 58. Key velocities present during the cutting process. 92. Figure 59. Knife tip velocities in the feed direction for the range of drum speeds. 93. Figure 60. Stalk deforlnation and resulting splitting caused by the action of a fast knife .. 94. Figure 61. Stress state of an elelTIent at the knife tip for high drUlTI speeds. Figure 62. Stalk defo11nation and resulting splitting caused by the action of a slow knife. 95. ...........................................................................................................................96 Figure 63. DalTIage caused by geolnetly of the knife lTIounting plate. 97.

(15) XIV. Symbols D geom. DrUITI inner curve geometry. Droller. Feed roller dianleter Young's Inodulus of elasticity Knife condition Knife speed Billet length. Mdamaged. Mass of dalnaged billets Initial nlass of specilnen / test saInple. M,nllliialed. Mass of ITIutilated billets. M.wllnd. Mass of sound billets Final Illass of speciIllen. N. NUInber of stalks cut Chopper drun1 rotational. Nl'oller. spe~d. Feed roller rotational speed NUlnber of tests. PR. Pour rate. R. NUInber of repeats. V. Cane variety NUInber of arI11S / knives on the drUITI. k. Nunlber of levels. n. NUl1lber of factors. v. Poisson's ratio. e. Anvil angle. Oknijewidlh. Angle of chopper knife arc. p. Density.

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