Continuous dynamic mixing of cohesive powders [Elektronische Ressource] / Volker Kehlenbeck

Volker Kehlenbeck

Informations

• Publié par: technische_universitat_munchen
• Publié le: 01 janvier 2006
• Nombre de lectures: 232
• Langue: Deutsch
• Poids de l'ouvrage: 25 Mo

Extrait

Technische Universität München
Lehrstuhl für Maschinen- und Apparatekunde




Continuous dynamic mixing
of cohesive powders



Dipl.-Ing. Volker Kehlenbeck




Vollständiger Abdruck der von der Fakultät Wissenschaftszentrum Weihenstephan für
Ernährung, Landnutzung und Umwelt der Technischen Universität München zur Erlangung
des akademischen Grades eines



Doktor-Ingenieurs
(Dr.-Ing.)



genehmigten Dissertation.




Vorsitzender: Univ.-Prof. Dr. rer. nat. habil. Rudi F. Vogel

Prüfer der Dissertation: 1. Univ.-Prof. Dr.-Ing. Karl Sommer
2. Univ.-Prof. Dr.-Ing. Jörg Schwedes,
Technische Universität Braunschweig
3. Prof. Dr.-Ing. John A. Dodds,
Ecole des Mines d´Albi, Frankreich
(schriftliche Beurteilung)



Die Dissertation wurde am 09.01.2006 bei der Technischen Universität München eingereicht
und durch die Fakultät Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung
und Umwelt am 16.02.2006 angenommen.




















































Dieser Titel ist auch im Shaker Verlag unter der ISBN 3-8322-5726-8 erschienen.

















To my parents


Ingrid and Reinhard Kehlenbeck


for everything they have done for me!



















Acknowledgements
This thesis is the result of my work as scientific employee at the Lehrstuhl für Maschinen- und
Apparatekunde of the Technische Universität München – Weihenstephan (February 1998 until
November 2003).
My most special thanks go to my doctoral advisor Univ.-Prof. Dr.-Ing. Karl Sommer who inspired
my fascination in powder technology, in particular in powder mixing. He shared with me his
universal knowledge during many engrossing discussions and the fascinating lectures of our
annual seminars. In addition, he gave me great freedom in realizing own ideas and in my
subsequent personal development. I also want to express my gratitude to Univ.-Prof. Dr.-Ing.
Jörg Schwedes who was one of my lecturers during my studies of Mechanical Engineering at
the Technische Universität Braunschweig. He is the one who initially stirred my interest in
powder technology and encouraged me to start a PhD. Prof. Dr.-Ing. John A. Dodds also
supervised a PhD thesis on continuous dynamic mixing at the Ecole des Mines d´Albi-Carmaux
(France). Therefore, I was very happy that he agreed to advise my work, too. I also whish to
express gratitude to Univ.-Prof. Dr. rer. nat. habil. Rudi F. Vogel for taking over the chair of the
PhD examination.
All former colleagues I want to thank very much for the terrific atmosphere at our institute. My
particular thanks go to my colleagues and close friends Dr.-Ing. Heinz Dauth, Dr.-Ing. Sven
Fischer, Markus Hartmann, Dr.-Ing. Jan Herrmann, Jürgen Hofmann, Dr.-Ing. Susanne Kuschel,
Dr.-Ing. Heidi Lankes and Dr.-Ing. Stefan Palzer. The time we spent together at the Lehrstuhl für
Maschinen- und Apparatekunde as well as during spare time activities and journeys I will never
forget! I am indebted to them that the expression friendship has taken on a new meaning for
me.
Without the fantastic help and support of the workshop members, especially Peter Rauscher,
Anton Fischer, Alfons Seitzl, Christian Stanglmaier and Hans Wagner, the build-up of the
complex experimental rigs would not have been possible. I also want to give many thanks to my
neighbor Wolfgang Schmidt who assisted me greatly during the planning of the electronic
installation of the main experimental rig.
All the students who helped me solving problems connected with the project deserve my
gratitude. Especially I want to mention Sofia Tempfli, who aided me very much with her
semester and following diploma thesis. She improved the in-line concentration measurement by
means of near-infrared spectroscopy and the calibration of the spectrometer. Bettina Weinzierl
also provided important assistance with her semester and following diploma thesis. She tested
and assessed dosing tube ends and dosing tube attachments, which were developed during the
project to improve the short-term dosing constancy of the volumetric feeders used. After their
diploma theses, Ms. Tempfli and Ms. Weinzierl worked for me as temporary scientific assistants
and ensured that the experimental examinations did not stop during my scientific stay at the
Particle Engineering Research Center at the University of Florida (USA). I also want to mention
Andreas Fischer, who developed the software to control the experimental rig during his diploma
thesis, and Jan-Dirk Prigge, who examined different possibilities to improve the sample
preparation necessary for the calibration of the near-infrared spectrometer used during his
semester thesis.
Mr. Daniel Dopfer, Dr. tech. Ralf Kehlenbeck, Dr. Lucy Kunz, Dr.-Ing. Heidi Lankes, Dr. Andreas
Niemöller, Dr.-Ing. Stefan Palzer and Dr. Ralf Weinekötter spent many hours of their spare time
reading and discussing my work.
The thesis was financially supported by the Deutsche Forschungsgemeinschaft (DFG) and the
International Fine Particles Research Institute (IFPRI). Besides gathering manifold experiences
and the scientific development, the financial support of the DFG offered me the opportunity of a
two-month stay at the Particle Engineering Research Center at the University of Florida (USA)
and to present the research results at different international conferences. The annual DFG
colloquia and our annual meetings of the PhD students I will miss in the future. Besides many
contacts with professors and their co-workers, also some true friendships formed. In this
context, I want to mention especially Dr. rer. nat. Ursula Dowe and Dr.-Ing. Günther Huber.
Without the sponsoring of more than one hundred companies, the build-up of the experimental
rigs would not have been possible. I want to mention and deeply thank the main sponsors of the
project and the main contact persons I owe the support:
The company Bruker Optik GmbH (Ettlingen, Germany) put the FT-NIR spectrometer
VECTOR 22/N at our disposal. Despite initial doubts, Mr. J. Gast, Dr. H. Weiler and
Dr. J.-P. Conzen believed in my vision of controlling the mixing process in a continuous mixer by
near-infrared spectroscopy. During the realization of the in-line adaptation and the necessary
calibration of the near-infrared spectrometer, Dr. A. Niemöller helped me very much. The
companies Gericke AG (Regensdorf, Switzerland) and Gericke GmbH (Rielasingen, Germany)
sponsored the continuous dynamic mixer GCM 500 and two volumetric feeders of the type
GAC 132. Dr. R. Weinekötter, Dr.-Ing. M. Kruse and Mr. E. Leeger I want to thank for the
discussions about powder mixing and powder dosing. The companies Sartorius AG (Göttingen,
Germany) and Global Weighing Technologies GmbH (Hamburg, Germany) made the whole
weighing equipment available. Mr. K. Thornagel, Mr. T. Konow and Mr. M. Stoppert enabled me
to realize many of my ideas during the project. Mr. J. Dittrich supported me in programming the
weighing controller used. The sponsoring of two suction conveyors by Mr. T. Volkmann and
Mr. T. Ramme from the company VOLKMANN GmbH (Soest, Germany) made the handling of
the huge amounts of powder necessary for continuous mixing experiments much easier. An
optimum operation of the suction conveyors was possible by the sponsoring of two bins from the
company Dietrich Reimelt GmbH & Co. KG (Rödermark, Germany). Mr. P.-G. Dellmann made
the sponsoring possible. Mr. W. Heldenberger and Mr. E. Pretsch from the company Rudolf Loh
GmbH & Co. KG (Herborn, Germany) made several Rittal switch cupboards and housings
available to protect the control computers and other sensitive equipment against dust. The
switch cupboards and housings contributed essentially to the attractive appearance of the
experimental rig.
All individuals and companies not specifically mentioned above but who also helped and
supported me during my work on my PhD I whish to thank as well.

List of symbols
Latin symbols

Average displacement of species 1 in x-direction [m] ∆x 1
2 Mean square deviation of the displacement of species 1 in [m] ∆x 1
x-direction
Single displacement of species 1 in x-direction [m] ∆x 1,i
& Mass flow [kg/s] m , ∆m/∆t,
dm/dt
& Average mass flow [kg/s] m
2Cross section area [m ] A
Absorbance unit [-] AU
3Chamber concentration (mass per chamber volume) [kg/m ] c
2Normalized dispersion coefficient D multiplied with ∆τ / ∆λ [-] CD
Normalized transport coefficient U mul