Based on LEAT’s discrete element codes, granular flow and mixing on conveying equipment are studied in two and three dimensions. Discrete element simulations, which are briefly introduced, provide detailed information on particle positions and velocities over time. This information is used to derive quantities characterizing the dynamic process of mixing. The main focus of the study presented is the mixing process of inhomogeneous particle ensembles on different grate types. For this purpose, the introduced mixing parameters are used to compare the mixing in a 3D situation with the corresponding 2D approximation on identical grates and to compare different grate designs in two dimensions.

1.
Scholz
,
R.
, and
Beckmann
,
M.
, 1991, “
Moeglichkeiten der Verbrennungsrueckfuehrung bei Restmuell in Rostfeuerungsanlagen
,” VDI-Bericht, 895, Prozessfuehrung und Verfahrenstechnik der Müllverbrennung,
VDI-Verlag
, Düsseldorf, pp.
69
138
.
2.
Kruell
,
F.
, 2002, “
Verfahren zur numerischen Simulation von Müllrostfeuerungen
,” Ph.D. thesis, Ruhr-Universitaet Bochum.
3.
Kruggel-Emden
,
H.
,
Wirtz
,
S.
,
Simsek
,
E.
, and
Scherer
,
V.
, 2006, “
Modeling of Granular Flow and Combined Heat Transfer in Hoppers by the Discrete Element Method (DEM)
,”
J. Pressure Vessel Technol.
0094-9930,
128
(
3
), pp.
439
444
.
4.
Goda
,
T. J.
,
Ebert
,
F.
, 2005, “
Three-Dimensional Discrete Element Simulations in Hoppers and Silos
,”
Powder Technol.
0032-5910,
158
, pp.
58
68
.
5.
Langston
,
P. A.
,
Al-Awamleh
,
M. A.
,
Fraige
,
F. Y.
,
Asmar
,
B. N.
, 2004, “
Distinct Element Modelling of Non-Spherical Frictionless Particle Flow
,”
Chem. Eng. Sci.
0009-2509,
59
, pp.
425
435
.
6.
Allen
,
M. P.
, and
Tildesley
,
D. J.
, 1987,
Computer Simulation of Liquids
,
Oxford University Press
,
New York
.
7.
Johnson
,
K. L.
, 1989,
Contact Mechanics
,
Cambridge University Press
Cambridge
.
8.
Schäfer
,
J.
,
Dippel
,
S.
, and
Wolf
,
D. E.
, 1996, “
Force Schemes in Simulations of Granular Materials
,”
J. Phys. I
1155-4304,
6
(
1
), pp.
5
20
.
9.
Kruggel-Emden
,
H.
,
Simsek
,
E.
,
Rickelt
,
S.
,
Wirtz
,
S.
, and
Scherer
,
V.
, 2007, “
Review and Extention of Normal Force Models for the Discrete Element Method
,”
Powder Technol.
0032-5910,
171
, pp.
157
173
.
10.
Cundall
,
P. A.
, and
Strack
,
O. D. L.
, 1979, “
A Discrete Numerical Model for Granular Assemblies
,”
Geotechnique
0016-8505,
29
(
1
), pp.
47
65
.
11.
Kharaz
,
A. H.
,
Gorham
,
D. A.
,
Salman
,
A. D.
, 2001, “
An Experimental Study of the Elastic Rebound of Spheres
,”
Powder Technol.
0032-5910,
120
, pp.
281
291
.
12.
Foerster
,
S. F.
,
Louge
,
M. Y.
,
Chang
,
H.
, and
Allia
,
K.
, 1994, “
Measurements of the Collision Properties of Small Spheres
,”
Phys. Fluids
1070-6631,
6
(
3
), pp.
1108
1115
.
13.
Di Maio
,
F. P.
, and
Di Renzo
,
A.
, 2004, “
Analytical Solution for the Problem of Frictional-Elastic Collisions of Spherical Particles Using the Linear Model
,”
Chem. Eng. Sci.
0009-2509,
59
, pp.
3461
3475
.
14.
Maw
,
N.
,
Barber
,
J. R.
, and
Fawcett
,
J. N.
, 1976, “
The Oblique Impact of Elastic Spheres
,”
Wear
0043-1648,
38
, pp.
101
114
.
15.
Kruggel-Emden
,
H.
,
Wirtz
,
S.
, and
Scherer
,
V.
, 2007, “
An Analytical Solution of Different Configurations of the Linear Viscoelastic Normal and Frictional-Elastic Tangential Contact Model
,”
Chem. Eng. Sci.
, submitted.
16.
Peters
,
B.
,
Dziugys
,
A.
,
Hunsinger
,
H.
,
Krebs
,
L.
, 2005, “
An Approach to Qualify the Intensity of Mixing on a Forward Acting Grate
,”
Chem. Eng. Sci.
0009-2509,
60
, pp.
1649
1659
.
17.
Hunsinger
,
H.
,
Vehlow
,
J.
,
Peters
,
B.
, and
Frey
,
H. H.
, 2000, “
Performance of a Pilot Waste Incinerator Under Different Air/Fuel Ratios
,”
Proc. of the International Conference on Incineration and Thermal Treatment Technologies (IT3)
,
Portland, Oregon
, May 8–12, CD-Rom.
18.
Oyama
,
Y.
, 1939, “
Studies on Mixing of Solids
,”
Bull. Inst. Phys. Chem. Res. Japan
, Report No. 5,
18
, pp.
600
639
.
19.
Duran
,
J.
, 2000,
Sands, Powders, and Grains, An introduction to the Physics of Granular Materials
,
Springer
,
New York
.
You do not currently have access to this content.