by R Johansson · 2014 · Cited by 10 — Both of the air classifiers with internal aerodynamic cycle investigated in the performed research are based around a centrifugal-crossflow separation zone. The
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THESIS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN PRODUCT AND PRODUCTION DEVELOPMENT AIR CLASSIFICATION O F FINE AGGREGATES ROBERT JOHANSSON DEPARTMENT OF PRODUCT AND PRODUCTION DEVELOPMENT CHALMERS UNIVERSITY OF TECHNOLOGY GÖTEBORG , SWEDEN DECEMBER 201 4
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Air Classificati on of Fine Aggregates Robert Johansson ISBN: 978-91-7597-136-0 Copyright 2014 © Robert Johansson Doktorsavhandlingar vid Chalmers tekniska högskola Ny serie Nr: 3817 ISSN 0346 -718X Published and distributed by Chalmers University of Technology Product and Production Development SE-412 96 Göteborg Cover: Printed in Sweden by Chalmers Reproservice Göteborg 201 4
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ii PUBLICATIONS This thesis contains the following papers. Paper A: Johansson , R. and Evertsson, M. , Circulating Air Classification of Manufactured Sand, Presented at International Minera l Processing Congress XXV 2010 , Published in conference proceedings 851 -858. ISBN 978 1 921522 28 4 Paper B: Johansson, R. and Evertsson, M., CFD Simulation of a Gravitational Air Classifier , Published in Mineral Engineering (Journal), 2012 Paper C: Johansson, R. and Everts son, M., An Empirical Study of a Gravitational Air Classifier , Published in Mineral Engineering (Journal), 2012 Paper D: Johansson, R. and Evertsson, M., Modelling of a mobile Gravitational -Inertial Air Classifier , Presented at European Symposium on Comminution & Classification 2013, Published in conference proceedings ISBN 978 -3-86844-551-0 Paper E: Johansson, R. and Evertsson, M., CFD simulations of a Centrifugal Air Classifier used in the aggregate industry , Published in Mineral Engineering (Journal), 2014 Paper F: Johansson, R. and Evertsson, M., Modelling of a Two-Stage Air Classifier , Presented at MEI conference Physical Separation 2013 Paper G: Johansson, R. and Evertsson, M., Simulation and Pilot Testing of a Circulating Air Classifier used in the Production of Manufactu red Sand, Submitted to Mineral Engineering (Journal), December 2014 CONTRIBUTIONS TO C O-AUTHORED PAPERS In all the papers A -G, Johansson and Evertsson initiated the idea. The implementation was performed by Johansson. Johansson wrote the paper with Evertsson as a reviewer.
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iii CONTENTS Abstract i Publications .. ii Contributions to co -authored papers ii Acknowledgements .. v 1 Introduction . 1 1.1 Aggregate materials and their use . 1 1.2 Production of fine aggregates for concrete 2 1.3 Aggregates influence on the concrete .. 4 1.4 Classification and screening . 6 1.5 Air classification . 9 1.6 Problems with air classification of manufactured sand 12 2 Objectives .. 13 2.1 Research outline .. 13 2.2 Research questions . 13 2.3 Delimitations . 14 3 Research approach . 15 3.1 Research methodology . 15 3.2 The research methodology applied on the performed research 17 3.3 Methods applied in the performed research .. 18 4 Literature review 23 5 Air classifier with internal aerodynamic cycle 27 5.1 Introduction of air classifiers with internal aerodynamic cycle .. 27 5.2 Empirical measurements on ai r classifiers with internal aerodynamic cycle 28 5.3 Simulation results on air classifiers with internal aerodynamic cycle . 35 6 Air classifier with open aerodynamic cycle . 41 6.1 Introduction of air classifiers with open aerodynamic cycle . 41 6.2 Empirical measurements on air classifiers with open aerodynamic cycle . 43 6.3 Simulation results on air classifiers with open aerodynamic cy cle 48 6.4 Empirical model of the investigated air classifier .. 55 7 Results and discussion . 61 7.1 Internal aerodynamic cycle . 61 7.2 External aerodynamic cycle .. 62 7.3 Lessons learned from the different air classifiers 64 8 Conclusions .. 67 8.1 General . 67 8.2 Answers to the research questions .. 68 8.3 Future work 71 References .. 73
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iv APPENDIX Paper A: Circulating Air Classification of Manufactured Sand Paper B: CFD Simulation of a Gravitational Air Classifier Paper C: Empirical Study of a Gravitational Air Classifier Paper D: Modelling of a mobile Gravitational -Inertial Air Classifier Paper E: CFD Simulation of a Centrifugal Air Classifier used in the Aggregate industry Paper F: Modelling of a T wo-Stage air Classifier Paper G: Simulation and Pilot Testing of a Circulating Air Classifier Used in the Production of Manufactured Sand
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v ACKNOWLEDGEMENTS First ly I would like to thank my supervisor Professor Dr. Magnus Evertsson. It has been a fun time and experience , resulting in both knowledge and very g ood memories. For the rest of my friends in the Chalmers Rock Processing Systems Group you all have my gratitude. Dr. Erik Hulthén, your experience as a former PhD student and you willingness to share it has aided me greatly. Dr. Magnus Bengtsson; thanks f or taking your time for long discussions about research and life. PhD student Johannes Quist and PhD student Gauti Asbjörnsson, it has been a great time travelling and working with you and I will miss that. Thanks to Project Manager, MSc . Rebecka Stomvall for both the fun time in the Vinnova project and your input on this thesis. I also would like to thank my former colleague Dr. Elisabeth Lee , thanks for some found memories and your correction of my English. I also wish to thank, in no special order, Dr. Christoffer Landström, Dr. Peter Gullberg and Dr. David Söderblom. As old friends from my time as an undergraduate student at Chalmers University of Technology you have shown me true friendship. I™ve lost track of the number of questions I have asked and t his thesis has been greatly aided by your support. This research would not have been possible without the financial support from the Development Fund of the Swedish Construction Industry (SBUF) , the Swedish national research program MinBaS (Minerals, Balla st, and dimensional Stone) and the Swedish innovation found Vinnova . Without the support from the quarry industry with equipment and material no funding would have been enough. A number of quarries have been visited during this research program especially during the Vinnova project; and I am grateful for your support. I specially want to thank Pär Johnning at NCC Roads, the freedom I have had to perform experiments in your quarry has been crucial to this thesis. Thanks to all who in some way helped me durin g this research, your patience, guidance and assistance have been appreciated. Finally I would like to thank my family for their long time support in everything I have done. Thanks to Charlotte, for sharing your love and happiness with me. Thank you Mum a nd Dad for the support and encouragement, you have always been there for me. Thanks to my brother with family for always making me feel welcome, your home is a space of peace that I visit too seldom. Robert Johansson Göteborg, December 2014
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