the effect of the particle size distribution on non-newtonian turbulent ...

More documents

Recommendations

Info

ABSTRACT THE EFFECT OF THE PARTICLE SIZE DISTRIBUTION ON NON-NEWTONIAN TURBULENT SLURRY FLOW IN PIPES The handling <strong>of</strong> solid-liquid suspensions is an important concern within <strong>the</strong> chemical and processing industries and many <strong>the</strong>oretical models have been proposed to try and explain and predict turbulent flow behaviour. However, <strong>the</strong> prediction <strong>of</strong> turbulent flow from only <strong>the</strong> viscous properties <strong>of</strong> non-Newtonian suspensions has over <strong>the</strong> years been questioned by researchers. This <strong>the</strong>sis considers <strong>the</strong>oretical models well established in <strong>the</strong> literature and <strong>the</strong> Slatter model, which uses both <strong>the</strong> rheology <strong>of</strong> <strong>the</strong> suspension and <strong>the</strong> <strong>particle</strong> <strong>size</strong> <strong>distribution</strong> <strong>of</strong> <strong>the</strong> solids. These models are used to analyze <strong>the</strong> experimental data and <strong>the</strong> <strong>effect</strong> that <strong>particle</strong> <strong>size</strong> and <strong>the</strong> <strong>particle</strong> <strong>size</strong> <strong>distribution</strong> has on turbulent flow behaviour. The literature concerning <strong>the</strong> rheological fundamentals relevant to fluid flow in pipes has been examined. The Newtonian turbulent flow model as well as <strong>the</strong> non-Newtonian models <strong>of</strong>Dodge & Metzner, Torrance, Kemblowski & Kolodziejski, Wilson & Thomas and Slatter have been reviewed. Test work was conducted at <strong>the</strong> University <strong>of</strong> Cape Town's Hydrotransport Research Laboratory using a pumped recirculating pipe test rig. The test apparatus has been fully described and calibration and test procedures to enable collecting <strong>of</strong> accurate pipeline data have been presented. Three slurries were used in test work namely kaolin clay, mixture I (kaolin clay and rock flour) and mixture 2 (kaolin clay, rock flour and sand) with ad,s <strong>particle</strong> <strong>size</strong> ranging from 24/Lm to 170/Lm. The yield pseudoplastic model has been used to model and predict <strong>the</strong> laminar flow <strong>of</strong> <strong>the</strong> suspensions that were tested and <strong>the</strong> meth9J adopted by Neill (1988) has been used to determine <strong>the</strong> rheological constants. The pipeline test results have been presented as pseudoshear diagrams toge<strong>the</strong>r with <strong>the</strong> <strong>the</strong>oretical model lines providing a visual appraisal <strong>of</strong> <strong>the</strong> performance <strong>of</strong> each model. The Slatter model predicts <strong>the</strong> test data best with <strong>the</strong> o<strong>the</strong>r <strong>the</strong>oretical models that were considered tending to under predict <strong>the</strong> head loss. The reason <strong>the</strong> Slatter model performs better than <strong>the</strong> o<strong>the</strong>r <strong>the</strong>oretical models is because this model can account for <strong>the</strong> wall roughness and <strong>particle</strong> roughness <strong>effect</strong>. Evidence to support this statement has been presented. This <strong>the</strong>sis highlights <strong>the</strong> fact that <strong>the</strong> <strong>particle</strong> <strong>size</strong> <strong>distribution</strong> is a vitally important property <strong>of</strong> <strong>the</strong> suspension and that it does influence turbulent flow behaviour. It shows that turbulence modelling using <strong>the</strong> <strong>particle</strong> roughness <strong>effect</strong> (eg Slatter, 1994) is valid and can be adopted for non-Newtonian slurries. It is concluded that <strong>the</strong> <strong>particle</strong> <strong>size</strong> <strong>distribution</strong> must be used to determine <strong>the</strong> <strong>particle</strong> roughness <strong>effect</strong> and this <strong>effect</strong> must be incorporated in <strong>the</strong> turbulent flow analysis <strong>of</strong> non-Newtonian slurries.
Preamble DECLARATION Page iii I, Gary Sven Thorvaldsen, hereby declare that to <strong>the</strong> best <strong>of</strong> my knowledge and belief, this <strong>the</strong>sis is essentially my own work and has not been submitted for <strong>the</strong> award <strong>of</strong> any o<strong>the</strong>r diploma or degree at any university or technikon. G S Thorvaldsen October 1996
Page 1: THE EFFECT OF THE PARTICLE SIZE DIS
Page 5 and 6: Preamble ACKNOWLEDGEMENrS Page v I
Page 7: Preamble Page vii CHAPTER 1: INTROD
Page 10 and 11: Preamble 3.8 Experimental Procedure
Page 12 and 13: Preamble Page xii LIST OF FIGURES P
Page 14: Preamble Page xiv 4.5 Optimum repre
Page 17 and 18: Preamble NOMENCLATURE Svrnbol Descr
Page 19 and 20: Preamble T shear stress Pa T y yiel
Page 23 and 24: Chapter I For example: Introduction
Page 25 and 26: Chapter 1 Introduction Page 1.5 1.3
Page 27 and 28: CHAPTER 2
Page 33: Chapter 2 Literature Review Page 2.
Page 46 and 47: Chapter 2 Literature Review Viscous
Page 48 and 49: Chapter 2 Literature Review • ..P
Page 54:
Chapter 2 Literature Review Page 2.
Page 58 and 59:
Page 61 and 62:
Page 63 and 64:
Page 66 and 67:
Page 68 and 69:
Page 71 and 72:
Chapter 2 Literature Review 2 o Q2
Page 73 and 74:
Page 75:
3.1 INTRODUCTION CHAPTER 3 EXPERIME
Page 79 and 80:
Chapter 3 Experimental Work Page 3.
Page 81 and 82:
Page 83:
Page 87 and 88:
Chapter 3 Experimental Work Table 3
Page 90:
Page 93:
Page 98 and 99:
Page 101:
Chapter 4 Results and Analysis Page
Page 120:
Page 126 and 127:
Page 128 and 129:
5.1 INTRODUCTION CHAPTERS DISCUSSIO
Page 131 and 132:
Chapter 5 Discussion Page 5.4 Whate
Page 133:
Chapter 5 Discussion Page 5.6 The n
Page 137:
Chapter 5 Discussion Page 5.10 Mood
Page 141 and 142:
Chapter 5 Discussion Page 5.14 laye
Page 146 and 147:
Chapter 6 Summary and Conclusions P
Page 148:
REFERENCES ALVES G E (1949), Flow <
Page 152:
References Page R.5 METZNER A B (19
Page 155 and 156:
References Page R.8 SPIEGEL M R (19
Page 157 and 158:
APPENDICES
Page 159:
Appendix A Detailed Pipe Test Resul
Page 165:
Page 170:
Page 174:
Page 180:
Page 184:
Page 190:
Page 194:
Page 200:
Page 204:
Page 210:
Page 214:
Page 220:
Page 224:
Page 230:
Page 234:
Page 238 and 239:
APPENDIXB
Page 240 and 241:
Appendix B Conference Paper ABSTRAC
Page 242:
Appendix B Conference Paper where T
Page 246 and 247:
Appendix B Conference Paper 2.4.6.3
Page 248 and 249:
Appendix B Conference Paper B.IO A
Page 254:
Appendix B Conference Paper 4.3.3 K
Page 258 and 259:
Appendix B Conference Paper s solid
Page 260:
Appendix B Conference Paper B.22 SL
show all

the effect of the particle size distribution on non-newtonian turbulent ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?