Discrete Element Method in the Design of Transport Systems: Verification and Validation of 3D Models

214 Pages·2019·30.11 MB·English

by  Daniel Gelnar, Jiri Zegzulka

Daniel Gelnar · Jiri Zegzulka
Discrete Element
Method in
the Design of
Transport Systems
Verifi cation and Validation of 3D Models
Discrete Element Method in the Design
of Transport Systems
Daniel Gelnar • Jiri Zegzulka
Discrete Element Method
in the Design of Transport
Systems
Verification and Validation of 3D Models
Daniel Gelnar Jiri Zegzulka
Technical University of Ostrava Technical University of Ostrava
Ostrava, Czech Republic Ostrava, Czech Republic
ISBN 978-3-030-05712-1 ISBN 978-3-030-05713-8 (eBook)
https://doi.org/10.1007/978-3-030-05713-8
Library of Congress Control Number: 2018964900
© Springer Nature Switzerland AG 2019
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Preface
This book presents an innovative proposal to optimize bucket elevators and related
transport processes using discrete element method (DEM). The book contents are
based on real and simulated measurements, procedures, and patents acquired when
working on the dissertation by Gelnar [1].
Before the book introduces and describes the newly improved design and optimi-
zation method based on DEM, it opens with the description of the conventional
method applied in the design of machinery using computer-aided design. Because
the newly proposed design and optimization method was studied and applied on
bucket elevators, bucket elevators are briefly described, including related calcula-
tions. The body of the book deals with the optimization of filling and discharge of
the bucket elevators using DEM. The reported measurements of physical properties
of selected materials serve as input values for the simulation method and basic cali-
bration of the model bulk material in the DEM simulation. Next, a 3D simulation
model is proposed, which is a digital twin of the validation bucket elevator. The
model works with programmed movements, speeds, and geometry to simulate the
filling and discharge of the transported material. As the use and accuracy of the
simulation results must be validated against real results, the book continues with a
validation of the dynamic flow of bulk materials on a newly designed, patented vali-
dation bucket elevator, i.e., a laboratory-scale validation bucket elevator. When the
simulation outputs are validated for the head section, simulations are made for the
boot of the bucket elevator. All the results are used to continuously optimize the
laboratory-scale validation bucket elevator and calibration of the bulk material. The
simulation method was also verified in real conditions. It was used for the simula-
tion and optimization of material filling and discharge of a real bucket elevator used
in the transport of abrasive materials. Based on the results, basic structural modifi-
cations are proposed to increase the bucket elevator performance. We believe that in
the future this innovative design method shall become more accurate and the
v
vi Preface
calculations will be obtained in a faster and more efficient manner. The book also
contains short videos – see the link http://bsc.vsb.cz, which shall hopefully enrich
the learning experience for students or help in the practice when designing bucket
elevators and similar equipment.
Ostrava, Czech Republic Daniel Gelnar
Jiri Zegzulka

Reference
1. Gelnar, D.: Verification and validation of DEM models of bulk materials used with bucket
elevators, and of possible real situation solutions in practice, when filling and discharging the
buckets. Ostrava: VŠB - Technical University of Ostrava, supervisor of dissertation: Prof. Ing.
Jiří Zegzulka, CSc. Report ISBN 978–80–248-3795-6 (2015)
Acknowledgment
Thanks to Bulk Solids Center Czech Republic (ENET, HGF VŠB-TUO) for
creating conditions for interdisciplinary research.
This paper was conducted within the framework of the project LO1404:
Sustainable development of ENET Centre, the project SP2018/47: Calibration and
experimental devices for the research and validation of simulation models and the
project Innovative and additive manufacturing technology - new technological solu-
tions for 3D printing of metals and composite materials, reg. no. CZ.02.1.01/0.0/0.
0/17_049/0008407 financed by Structural Founds of Europe Union.
vii
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Basic Description of DEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3 Basic Description of Bucket Elevators . . . . . . . . . . . . . . . . . . . . . . . . . 17
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4 Bucket Elevator Filling and Discharge . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1 Discharge of Buckets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.1.1 Gravity Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.1.2 Mixed Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.1.3 Centrifugal Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.2 Bucket Filling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.2.1 Direct Flow of Material Filling . . . . . . . . . . . . . . . . . . . . . . 38
4.2.2 Theoretical Calculation of Direct Flow Filling . . . . . . . . . . 39
4.2.3 Scooping of Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.4 Combined Method of Bucket Filling . . . . . . . . . . . . . . . . . 42
4.2.5 Theoretical Calculation of Scooping . . . . . . . . . . . . . . . . . 42
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
5 The New Method of Design and Optimization . . . . . . . . . . . . . . . . . . 49
6 Input Parameters for DEM – Bulk Material . . . . . . . . . . . . . . . . . . . . 51
6.1 Selection of Particle Shape for Simulation
and Real Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
6.2 Measurements of Apparent Density and Volumetric Weight . . . . . 55
6.3 M easurements of Internal Friction . . . . . . . . . . . . . . . . . . . . . . . . . 56
6.4 Measurements of External Friction . . . . . . . . . . . . . . . . . . . . . . . . . 57
6.5 Measurements of Repose Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
6.6 Measurements of Particle Size Distribution . . . . . . . . . . . . . . . . . . 61
6.7 M easurements of Coefficient of Restitution . . . . . . . . . . . . . . . . . . 64
ix
x Contents
6.8 Measurements of Sliding Friction . . . . . . . . . . . . . . . . . . . . . . . . . 65
6.9 Measurements of Rolling Friction . . . . . . . . . . . . . . . . . . . . . . . . 68
6.10 Summary of Results for DEM Input Parameters . . . . . . . . . . . . . 72
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
7 Input Parameters for DEM – Geometry of the 3D
Model and Validation Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
7.1 Creation of Simulation Environment . . . . . . . . . . . . . . . . . . . . . . . 75
7.2 Design and Creation of the Validation Bucket . . . . . . . . . . . . . . . . 78
Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
8 Input Parameters – Kinematic Properties . . . . . . . . . . . . . . . . . . . . . . 89
9 Process Validation and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
9.1 Direct Measurements and the Validation Bucket Elevator . . . . . . . 95
9.2 E valuation of the Direct Method Using DS-NET
Strain Gauge System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
9.3 I ndirect Measurements and the Validation Bucket Elevator . . . . . . 96
9.4 E valuation of the Indirect Method Using PIV Software
(Particle Image Velocimetry) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
9.5 V alidation – Preparation of Measurements . . . . . . . . . . . . . . . . . . . 100
9.6 V alidation – Measurement Results . . . . . . . . . . . . . . . . . . . . . . . . . 104
10 T he Results for the Optimization of Bucket Filling
and Discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
10.1 T he Results for Optimization of Bucket Discharge . . . . . . . . . . . 131
10.2 T he Results for Optimization of Bucket Filling . . . . . . . . . . . . . . 137
11 T he Results for Optimization of Filling Bulk Material
in the Bucket to Minimize Travel Resistance and Impacts . . . . . . . . 165
12 T he Results for Process Optimization of Bulk Material
Filling into the Bucket to Minimize Abrasive and Destructive
Impacts of the Bucket Edge on the Transported Mass . . . . . . . . . . . . 171
13 T he Optimization of Bucket Discharge to Maximize
the Transported Volume and to Minimize Material Fall
Down the Shaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
14 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
Interesting Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Awards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Abbreviations
CAD Computer-aided design
CCD camera Charge-coupled device – a camera with a light-sensitive chip able
to bind electric charge
CFD Computational fluid dynamics
DEM Discrete element method
EDEM Software using the discrete element method to simulate bulk
materials
FEM Finite element method
MBD Multibody dynamics
PIV Particle image velocimetry – a method using the pixel difference
between two images to determine the speed and travel of particles
in time
xi