TY - JOUR
T1 - Detailed modeling and process design of an advanced continuous powder mixer
AU - Toson, Peter
AU - Siegmann, Eva
AU - Trogrlic, Martina
AU - Kureck, Hermann
AU - Khinast, Johannes
AU - Jajcevic, Dalibor
AU - Doshi, Pankaj
AU - Blackwood, Daniel
AU - Bonnassieux, Alexandre
AU - Daugherity, Patrick D.
AU - am Ende, Mary T.
PY - 2018/12/1
Y1 - 2018/12/1
N2 - A vertical in-line continuous powder mixing device (CMT – Continuous Mixing Technology) has been modelled with the discrete element method (DEM) utilizing a calibrated cohesive contact model. The vertical design of the mixing device allows independent control of mean residence time (MRT) and shear rate. The hold-up mass and outlet flow are controlled by an exit valve, located at the bottom of the in-line mixer. A virtual design of experiments (DoE) of DEM simulations has been performed and parameters such as particle velocities, powder bed shape, residence time distribution (RTD), travel distance, and mixing quality are evaluated for the complete operating space. The RTD of the DEM model has been validated with tracer experiments. The resulting RTD has been fitted with an analytical form (generalized cascade of n continuous stirred tank reactors) and utilized to study the downstream response of the continuous mixing device to upstream fluctuations in the inlet material stream. The results indicate a high mixing quality and good filtering properties across the operating space. However, the combination of low hold-up mass and high impeller speeds leads to a reduced filtering capability and wider exit valve openings, indicating a less desirable operating point.
AB - A vertical in-line continuous powder mixing device (CMT – Continuous Mixing Technology) has been modelled with the discrete element method (DEM) utilizing a calibrated cohesive contact model. The vertical design of the mixing device allows independent control of mean residence time (MRT) and shear rate. The hold-up mass and outlet flow are controlled by an exit valve, located at the bottom of the in-line mixer. A virtual design of experiments (DoE) of DEM simulations has been performed and parameters such as particle velocities, powder bed shape, residence time distribution (RTD), travel distance, and mixing quality are evaluated for the complete operating space. The RTD of the DEM model has been validated with tracer experiments. The resulting RTD has been fitted with an analytical form (generalized cascade of n continuous stirred tank reactors) and utilized to study the downstream response of the continuous mixing device to upstream fluctuations in the inlet material stream. The results indicate a high mixing quality and good filtering properties across the operating space. However, the combination of low hold-up mass and high impeller speeds leads to a reduced filtering capability and wider exit valve openings, indicating a less desirable operating point.
KW - Cohesive contact model
KW - Continuous manufacturing
KW - Continuous mixing technology
KW - Discrete element method
KW - Operating space
KW - Process modeling
KW - Residence time distribution
UR - http://www.scopus.com/inward/record.url?scp=85054434153&partnerID=8YFLogxK
U2 - 10.1016/j.ijpharm.2018.09.032
DO - 10.1016/j.ijpharm.2018.09.032
M3 - Article
C2 - 30268852
AN - SCOPUS:85054434153
SN - 0378-5173
VL - 552
SP - 288
EP - 300
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
IS - 1-2
ER -