Design Aspects of Multiple Driven Belt Conveyors

168 Pages·2007·3.57 MB·English

by  The Nuts

Design Aspects of Multiple Driven Belt Conveyors

Ashley Nuttall
Cover illustration: Courtesy of Fenner-Dunlop B.V.
Design Aspects of Multiple Driven Belt Conveyors

Proefschrift

ter verkrijging van de graad van doctor
aan de Technische Universiteit Delft,
op gezag van de Rector Magnificus prof. dr. ir. J.T. Fokkema,
voorzitter van het College voor Promoties,
in het openbaar te verdedigen op maandag 26 november 2007 om 12:30 uur

door
Ashley Jan George NUTTALL
werktuigkundig ingenieur
geboren te Rotterdam.
Dit proefschrift is goedgekeurd door de promotor:
Prof. dr. ir. G. Lodewijks

Samenstelling promotiecommissie:

Rector Magnificus, Voorzitter
Prof. dr. ir. G. Lodewijks, Technische Universiteit Delft, promotor
Prof. dr. ir. B. De Schutter, Technische Universiteit Delft
Prof. dr. J.A. Ferreira, Technische Universiteit Delft
Dr. ir. A. van Beek, Technische Universiteit Delft
Prof. dr.-ing. L. Overmeyer, Institute of Transport and Automation Technology
Prof.dr. ir. D.J. Rixen, Technische Universiteit Delft

TRAIL Thesis Series no. T2007/12, the Netherlands TRAIL, Research School

TRAIL Research School
PO Box 5017, 2600 GA Delft
The Netherlands
Phone: [phone]
Fax: [phone]
E-mail:
Preface
In 1992 Dunlop-Enerka BV, located in Drachten, the Netherlands, started to develop a pouch
shaped closed belt conveyor system called the Enerka-Becker System (or E-BS). It featured a
revolutionary method of supporting the belt and included a multipoint drive system. Although
multiple drives were integrates into the design of this conveyor system, little was actually
known about how to coordinate the spatially distributed drive stations. As this system was
only built with relatively small belt lengths (under 500 meters) and a small motor spacing, the
belt stress caused by the introduction of drive forces was relatively low and not a limiting
factor for the system. Therefore, a simple control method sufficed. However, the question was
if larger systems would still work with this simple control method. Gabriël Lodewijks, who
had also been involved with part of the development of the E-BS, also identified this issue. As
little was known with respect to the implementation of multiple drives not only in the E-BS,
but also in more conventional belt conveyor systems, he formulated a research proposal for
the coordinated control of multiple driven belt conveyor system. This proposal formed the
base for my PhD research. Initially, the focus was put on the coordinated control of the multi-
motor layout. However, as little was know about how the current simple control method
adopted in the E-BS would perform in a large scale application, the focus was shifted to
identifying problems that can be expected when adapting this method of control.

My special thanks goes to Gabriël Lodewijks, who inspired me with his fascination of
applying scientific research on belt conveyor systems and who encouraged me throughout my
research. Without his enthusiasm and drive this thesis would not have been possible. In
addition I would like to thank Ton Klein Breteler for his ideas and guidance during my PhD
work.
This research was also performed in cooperation with Fenner-Dunlop BV. The support I
received from Michiel Eijpe and his colleagues is greatly appreciated.

I would also like to thank all the colleagues from Transport Engineering and Logistics for
their interest in my research, sharing ideas on different subjects and the pleasant working
environment.

Last but not least I would like to thank my mum, dad and family for their love and support,
and my friends just for being who they are.
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ii Design Aspects of Multiple Driven Belt Conveyors
Contents
Preface ........................................................................................................................................ i
1 Introduction .................................................................................................................. 1
1.1 Multiple driven belt conveyors....................................................................................... 1
1.2 Distributed drive power and tension control .................................................................. 5
1.3 Research questions and scope of study .......................................................................... 7
1.4 Outline of thesis.............................................................................................................. 8
2 Multiple driven transport systems.............................................................................. 9
2.1 Mechanical drive configurations . 9
2.1.1 Single drive configuration .............................................................................................. 9
2.1.2 Multiple drive configuration......................................................................................... 11
2.2 Categorisation of multiple driven systems ................................................................... 13
2.3 Existing multiple driven transport systems with flexible links .................................... 16
2.3.1 Belt conveyors .............................................................................................................. 16
2.3.2 Printing presses............................................................................................................. 17
2.3.3 Trains............................................................................................................................ 19
2.3.4 Chain conveyors ........................................................................................................... 21
2.3.5 Fuel cell car concept..................................................................................................... 22
2.4 Comparison of systems ................................................................................................ 23
3 Existing models for belt conveyor systems............................................................... 27
3.1 Main components of the Enerka-Becker System ......................................................... 27
3.1.1 Belt ............................................................................................................................... 28
3.1.2 Belt support .................................................................................................................. 30
3.1.3 Drive units .................................................................................................................... 30
3.1.4 Loading station ............................................................................................................. 32
3.1.5 Discharge and belt turnover.......................................................................................... 33
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iv Design Aspects of Multiple Driven Belt Conveyors
3.2 Belt dynamics ............................................................................................................... 33
3.3 Motion resistances ........................................................................................................ 35
3.3.1 Main resistances ........................................................................................................... 36
3.3.2 Secondary resistances................................................................................................... 40
3.3.3 Slope resistances........................................................................................................... 43
3.3.4 Special resistances ........................................................................................................ 43
3.4 Drive stations................................................................................................................ 43
3.4.1 Induction motor and inverter ........................................................................................ 44
3.4.2 Gear reduction box and drive wheel............................................................................. 48
4 Modelling resistance in the E-BS .............................................................................. 49
4.1 Indentation rolling resistance in the E-BS.................................................................... 49
4.1.1 Modelling the belt’s viscoelastic surface ..................................................................... 49
4.1.2 Maxwell model............................................................................................................. 51
4.1.3 Pressure distribution and rolling friction due to hysteresis .......................................... 52
4.1.4 Finding the Maxwell parameters .................................................................................. 56
4.1.5 Results .......................................................................................................................... 58
4.2 Resistance in horizontal curves .................................................................................... 60
4.2.1 Modelling the curve resistance..................................................................................... 60
4.2.2 Results .......................................................................................................................... 62
4.3 Adding a dynamic friction model to the dynamic belt model ...................................... 63
5 Traction in a wheel driven belt conveyor ................................................................. 69
5.1 Traction versus slip ...................................................................................................... 69
5.1.1 Shear stress distribution................................................................................................ 70
5.1.2 Correction factor........................................................................................................... 72
5.1.3 Experimental validation................................................................................................ 73
5.1.4 Adding the traction model to the dynamic belt model ................................................. 77
5.2 Traction versus wear..................................................................................................... 78
5.2.1 Wear mechanism .......................................................................................................... 79
5.2.2 Wear experiments......................................................................................................... 81
5.2.3 Required number of drive stations ............................................................................... 82
6 Dynamics of multiple driven belt conveyors ............................................................ 85
6.1 Comparison of belt behaviour during starting.............................................................. 85
Contents v
6.1.1 Single drive belt conveyor............................................................................................ 86
6.1.2 Multiple drives belt conveyor....................................................................................... 93
6.2 Optimising starting behaviour ...................................................................................... 99
6.2.1 Start curve shape .......................................................................................................... 99
6.2.2 Sequenced starting...................................................................................................... 103
6.2.3 Layout alterations ....................................................................................................... 109
6.3 Influence of belt loading............................................................................................. 111
6.4 Stopping...................................................................................................................... 117
7 Conclusions ............................................................................................................... 121
Appendix A: Dynamic conveyor belt model ...................................................................... 127
Nomenclature........................................................................................................................ 133
References ............................................................................................................................. 137
Summary............................................................................................................................... 143
Samenvatting ........................................................................................................................ 147
Biography.............................................................................................................................. 151
TRAIL Thesis Series ............................................................................................................ 153
vi Design Aspects of Multiple Driven Belt Conveyors