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

Development of a SingleDrum Chopper Concept fora 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

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.

I 7 I

Matthew Gavin Barnes

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derived frOln the published or unpublished work of others has been acknowledge in the text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

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.

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

111ill. 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 syste111. 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 speedphotography for analysis into the causes ofda111age 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.

VI

Contents

Statement of access ii

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 , : 3

1.3 Ailn 3

1.4 Scope 3

1.5 Tllesis outliIle 4

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 ~ 11

2.2 Chopper systelns used in silnilar industries 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

3.2.1. Instrulnentation and recording devices 30

3.3 Description of the experilnent 30

3.3.1. Vat·iables 30

VB

3.3.2. Experinlental procedure 32

3.3.3. Expel·imel1tal design 33

3.3.4. Quantitative experin1ental outputs 35

3.4 Results 35

3.4.1. Cane and juice losses 35

3.4.2. High speed photography 38

3.5 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

3.6 Conclusions from the laboratory billeting experinlents 40

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

4.4 Conclusions from the concept design 47

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

5.4 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

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

6.2.1. Instrunlentation and recording devices 67

6.3 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

6.4 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 ~ 97

6.7 COl1clusions froln the prototype testing _.. ~ 98

7. Conclusions 99

7.1 Outcolnes 100

7.2 RecoInnlendations for further developInenfofthe chopper concept 101

References 103

Tables

Table 1

Table 2

Table 3

Table 4

Table 5

Table 6

Table 7

Table 8

Table 9

Table 10

Table 11

Table 12

Table 13

Table 14

Table 15

Table 16

Table 17

Table 18

Table 19

Table 20

Table 21

Table 22

Table 23

IX

Harvester production data (Jakeway, 2003) 17

Mechanical properties of sugarcane (Keenliside, 1985) 21

Levels selected for each independent variable 31

Experilnental plan for the laboratory experilnents 34

Analysis of variance for lnass loss under the independent input variables 37

COlnparison anlongst anvil angle levels for which significantly affected lnass

loss 37

Levels selected for each independent variable 50

Target billet lengths and cOl1'esponding chopper drum speeds used in the

lTIodellillg 50

Finite elelnent lTIodelling plan 51

Material propeliies: linear elastic paranleters and density 53

Global contact properties 55

Billet velocities upon contact with extraction chalnber wall (lll/s) 60

Levels selected for each independent variable 69

Pour Rates and Corresponding Target Bundle Weights 70

Target billet lellgths and corresponding chopper druln speeds used in the testing

........................................................................................................................... 71

Prototype testing experilnental plan ! ••••••••••••••••••••••••••••••••••••••••••••••••••• 74

Quantitative experiJnental results 77

Analysis of variance for total lTIaSS loss under druln speed and pour rate factors

...........................................................................................................................79

COlnparisons amongst levels for chopper drulli speed on lTIaSS loss 80

Analysis of variance for lnass loss per cut under drUlTI speed and pour rate

factol4 s 82

COlnparisons alnongst levels for chopper drum speed on lnass loss per cut per

lnetre 82

ANOVA for percentage of sound billets under druln speed and pour rate factors

........................................................................................................................... 84

ANOVA for percentage of dalnaged billets under druln speed and pour rate

facto14 s 84

Table 24

Table 25

Table 26

x

ANOVA for percentage of tTIutilated billets under drutn speed and pour rate

factot~s 84

CotTIparisons atTIongst levels for chopper drUtll speed on percentage of sound

billets 85

C0111parisons atTIongst levels for chopper drutTI speed on percentage of

lnutilated ,billets ~ 85

Xl

Figures

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22a

Figure 22b

Most recent lllodel John Deere track driven sugarcane chopper harvester 7

Fundalllehtal cOlnponents of a lllodern ll1echanical sugarcane harvester (BSES,

2002) 8

Rotary pinch chop systelll configurations (Hockings and Davis, 1999) 11

Chopper systeln in a 1998 lnodel CatlleCa harvester 11

Chopper test rig used in the BSES trials (Backings and Davis, 1999) 12

Schen1atic of a Claas Jaguar 830 forage harvester chopper drun1 (Claas, 2002)

........................................................................................................................... 15

Schelnatic of a Claas Jaguar 830 forage harvester shear bar and pivot asselnbly

(Claas, 2002) 15

Schetnatic of a Claas Jaguar 830 forage harvester sharpening stone and holder

asselnbly (Claas, 2002) 16

Claas Jaguar 830 forage harvester chopper knife 16

Mature crop of sugarcane prior to harvest 18

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

Typical stress-strain curve for sugarcane in"bending (Keenliside, 1985) 21

Behaviour of 6n10thy grass during cutting with knife and counter-shear

(PeI4 SS0t1, 1987) 22

Screenshot of (a) input panel, and (b) results panel for trash layer calculator

(Lewis, 2006) 24

Predicted bin weights for 200 mn1 billets 24

Predicted bin weights for 150 tTItTI billets ,.~ 25

Predicted bin weights for 100 n1m billets 25

Laboratoly cutting experilnent apparatus 29

Anvil fratne showing the Inounts for the different angle settings 29

Schetnatic of the cutting process studied in this set of experilnents 30

Cutting edge width of the new and blunt knife 32

The effect of each variable on the Inean value of lnass loss 376

The effect of each variable on the percelltage of cane and juice loss per cut per

111etre of stalk 37

Figure 23

Figure 24

Figure 25

Figure 26

Figure 27

Figure 28

Figure 29

Figure 30

Figure 31

Figure 32

Figure 33

Figure 34

Figure 35

Figure 36

Figure 37

Figure 38

Figure 39

Figure 40

Figure 41

Figure 42

Figure 43

Figure 44

Figure 45

Figure 46

Figure 47

Figure 48

Figure 49

Figure 50

Figure 51

Figure 52

Figure 53

Figure 54

Figure 55

XlI

High speed photography in1ages showing billet end dan1age caused by the

cuttil1g pI~ocess 38

Geol1letric restraints on a sugarcane harvester 43

Chopper drUlTI geOlTIetry delllonstrating replaceable inner curves 44

Kllife end pl·ofile 45

Knife l'ake 46

Deflectol~ plate geolnetly 47

Geometry of the dynalnic model built in ELFEN 52

Three drunI cutting arin profiles: (l)-D1; (2)-D2; (3)-D3 52

Mesh applied to the Inodel geolnetry 54

Mesh appljed to the drUln cUttil1g arnl and close-up of knife nIesh 54

Billet trajectory results for the fast druln speed (438 rpIn) 57

Billet trajectoly results for the Illediun1 drulli speed (292 rpm) 58

Billet trajectoly result~ for the slow druln speed (219 rpIn) 58

Desired location of billet contact on extraction chalnber back wall 59

Geolnetric lTIodel and photograph of the prototype chopper systeln test rig 63

PI'ototype cllopper drull1 63

Replaceable inner druln curve plates (three different geolnetries) 64

Test rig sllear bar and pivot. 64

Test rig electric lnotor, gearbox, spider coupling and variable speed control 65

Test rig reduced width feed roller and cradle eo 65

Test r'ig feed train 66

Test rig hydraulic roller lllotors aneJ power pack 67

:Harvester separation chan1ber and test rig,replicate 67

Cut out in the side of the ATR wall alld high speed calnera and halogen light

setup 68

Large Bundle (300 t/hr equivalent) 72

SanIple after being sorted into billet qualiD'~categories 76

The'effect of chopper druIll speed on the lnean value of total Inass loss 78

The effect of pour rate on the lnean value oftotallnass loss 79

The effect of chopper druln speed on lnean lnass loss per cut. 81

The effect of pour rate on lnean mass loss per cut per lnetre 81

The effect of druln speed and pour rate on billet quality (data Ineans) 83

Histograllls of the average billet length distribution for each target billet length

........................................................................................................................... 86

Still itnages of the high speed footage taken for test number 11 89

Figure 56

Figure 57

Figure 58

Figure 59

Figure 60

Figure 61

Figure 62

Figure 63

XUI

Still ilnages of the high speed footage of the billet trajectolY for a target billet

length of200 InITI (Ndrum == 438 rpln) 90

Still ilTIage of the lnaterial trajectory recorded by the normal speed calnera 91

Key velocities present during the cutting process 92

Knife tip velocities in the feed direction for the range of drum speeds 93

Stalk deforlnation and resulting splitting caused by the action of a fast knife .. 94

Stress state of an elelTIent at the knife tip for high drUlTI speeds 95

Stalk defo11nation and resulting splitting caused by the action of a slow knife

...........................................................................................................................96

DalTIage caused by geolnetly of the knife lTIounting plate 97

Symbols

Dgeom

Droller

Mdamaged

M,nllliialed

M.wllnd

N

Nl'oller

PR

R

V

k

n

v

e

Oknijewidlh

p

DrUITI inner curve geometry

Feed roller dianleter

Young's Inodulus of elasticity

Knife condition

Knife speed

Billet length

Mass of dalnaged billets

Initial nlass of specilnen / test saInple

Mass of ITIutilated billets

Mass of sound billets

Final Illass of speciIllen

NUInber of stalks cut

Chopper drun1 rotational spe~d

Feed roller rotational speed

NUlnber of tests

Pour rate

NUInber of repeats

Cane variety

NUInber of arI11S / knives on the drUITI

Nunlber of levels

NUl1lber of factors

Poisson's ratio

Anvil angle

Angle of chopper knife arc

Density

XIV