Modelling non-homogeneous flow and residence time distribution in a single-screw extruder by means of Markov chains

Denis Ponomarev (1, 2) , Élisabeth Rodier (1) , Martial Sauceau (1) , Clémence Nikitine (3, 1) , Vadim Mizonov (2) , Jacques Fages (1)

1 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement
2 Department of Applied Mathematics (Ivanovo, Russie)
3 LGPC - Laboratoire de Génie des Procédés Catalytiques

Non-homogeneous velocity distribution of the flow in the channel of a single-screw extruder is taken into account by a new model developed on the basis of the Markov chains. This model allows calculating the Residence Time Distribution (RTD) as well as the influence of the operating conditions on the process at any velocity distribution in the channel. It has been used to represent experimental results on mass flow rate and RTD previously obtained by extrusion of an acrylic polymer, Eudragit E100, at different temperatures and screw rotation speeds. The diffusion coefficient is the only adjusting parameter of the model. It was shown that it does not depend on the screw rotation speed and a correlation between this diffusion coefficient and the barrel temperature was found. The model provides global understanding of the transport kinetics of the flowing material through the extruder according to its behaviour and better describes the progress of the polymer flow all along the barrel from the hopper to the die.

Mots clés: Residence time distribution; Polymer processing; Extrusion; Markov chain; Mathematical modelling

Domaines: Génie des procédés; Modélisation et simulation; Probabilités [math.PR]

Denis Ponomarev, Élisabeth Rodier, Martial Sauceau, Clémence Nikitine, Vadim Mizonov, et al.. Modelling non-homogeneous flow and residence time distribution in a single-screw extruder by means of Markov chains. Journal of Mathematical Chemistry, 2012, 50 (8), pp.2141-2154. ⟨10.1007/s10910-012-0022-x⟩. ⟨hal-01618291⟩