Modelling of the compactibility of cohesive powders by roller press
Final Report Abstract
The objective of the project was to determine essential process parameters cohesive powders during compaction. These parameters are useful to design compaction in roller press. Experiments were performed in 40 mm of diameter and 70 mm height cylindrical chamber for three kinds of cohesive powders widely used in industry microcrystalline cellulose MCC, bentonite and limestone. The behavior of cohesive powders during compaction in hydraulic press was analyzed first. The initial density, the density and the instantaneous density during process of powders compaction were also calculated. The influence of maximum compaction pressure and deformation rate was examined. The modulus of elasticity E of experimental powders was calculated in dependence of deformation rate v, maximum compaction pressure p and material. After compaction experiments the strength of tablets were tested for three values of consolidating pressures p=30, 45 and 60 MPa and for two different deformation rates in hydraulic press. From uniaxial compaction tests performed on universal testing machine for loading and unloading the modulus of elasticity E was calculated on the basis of the first linear part of unloading. From these tests the elastic recovery was also calculated. With DEM method uniaxial and roller press compaction were modeled. Complete new programs algonthm in PFC Itasca software were written for both types of apparatus. In both cases of modeling geometry and material parameters are correlated with reality. Modeled values were compared with results from experiments obtained on universal testing machine and laboratory roller press.
Publications
- L Grossmann, J Tomas Flow and Compaction Properties of Cohesive Powders in the Medium Pressure Range 16th International Congress of Chemical and Process Engineering, CHISA, Prague 2004
- L Grossmann, J Tomas Einfluss der Schuttguteigenschaften auf die Auslegung von Walzenpressen GVC-Fachausschuß "Agglomerations- und Schüttguttechnik", Tubingen 2005
- L Grossmann, J Tomas Measurement of the Compaction Properties of Cohesive Powders Using the Press Shear Cell, Powder & Grams, Stuttgart 2005
- L Grossmann, P Müller, J Tomas Kompressionseigenschaften von kohasiven Schüttgütern, Maschinenbau und Technik des 21 Jahrh , Sevastopol 2005
- L Grossmann, P Müller, J Tomas Untersuchung der Kompressionseigenschaften von Schüttgütern mittels einer Hydrauhkpresse GVC-Fachausschusse "Agglomerationsund Schüttguttechnik" und "Lebensmittelverfahrenstechnik", Reinbeck 2006
- P Müller, L Grossmann, J Tomas Ermittlung des Verdichtungsverhaltens von Schüttgütern mit einer Hydraulikpresse Chemie-Ingenieur-Technik, 78(6), 721-726 2006
- M Stasiak Testing mechanical properties of powders in two laboratories The IVT Colloquium, Magdeburg 2007
- M Stasiak, Mechanical parameters of plant granular materials, The chair meeting of The Department of Mechanical Process Engineering, Magdeburg 2007
- M Stasiak, J Tomas, M Molenda, L Grossmann P Müller Influence of technological parameters on compaction and flow behavior of cohesive powders PROCEEDINGS, 4th International Symposium Reliable Flow of Particulate Solids (RELPOWFLO IV), 10th - 12th June 2008, Tromso, Norway
- M Stasiak, J Tomas, M Molenda, P Müller Compaction and flow behavior of cohesive powders Submitted 27 06 2008 to Electronic Journal of Polish Agricultural Universities
- L Grossmann, J Tomas Flow properties of cohesive powders tested by press shear cell Particulate Science and Technology, 24, 353-367, 2006
- L Grossmann, J Tomas, B Csoke Compressibility and flow properties of a cohesive limestone powder in a medium pressure range Granular Matter, 6, 103-109, 2004
- L Grossmann, J Tomas, B Csoke Flow properties of cohesive powders tested by a press shear cell International Congress Particle Technology, PARTEC, Nürnberg 2004
- L Grossmann, J Tomas, D Herold, K Sommer Expenmentelle Untersuchung der Verdichtung von kohasiven Schüttgütern mit einer Walzenpresse Aufbereitungs Technik, 47, 22-29, 2006
