Applications with keyword: Simulation
The performance and robustness of the SpinChem® rotating bed reactor (RBR) technology was examined and compared to a fixed bed reactor (FBR) using ANSYS Fluent. By means of flow simulations through loosely packed beds, the RBR was found to be extremely robust with respect to the level of packing of the solid phase within, while the FBR was negatively affected by channelling.
ANSYS Fluent was used to make simulations of a spinning RBR and a stationary FBR with the same geometry. The simulated bed was in both cases split into two halves so that a loosely packed region could be modelled alongside an optimally packed region. The flow rate determined for the RBR at optimal packing was pumped through the FBR for all degrees of packing. Homogeneous packing was simulated by assigning the region a specific permeability coefficient corresponding to that of an ion exchange resin of uniform particle size. This value served as a reference value for the simulations, and corresponds to a pressure drop of 0.054 bar/m for water at 20°C with a linear velocity of 1 mm/s. Moderate and severe channelling was assigned specific permeability values corresponding to 133% and 200% of that of the reference, respectively.
Computational fluid dynamics simulations is an important tool in the optimization of geometries during development of SpinChem® rotating bed reactor (RBR) products. The image shows velocity vectors in a cross section of the flow around a SpinChem® RBR, in a flower baffled reaction vessel, simulated using ANSYS Fluent software under typical laboratory conditions.
Conditions: The flow was simulated in ANSYS Fluent 17.1 using the steady MRF model at 500 rpm and the SST k-omega turbulence model on a mesh of 0.96 million elements. All dimensions used was identical to the SpinChem® RBR S221 and closely matched the SpinChem® flower baffled reaction vessel V221.
A rotating bed reactor containing ion exchange beads was modeled in flower-baffled reaction vessels. It was shown that the baffles are vital for reducing surface vortexes and circular flow within the vessel. The authors concluded that the flow rates through the packed bed and reaction rates tend to increase with deeper baffles.
Hilde Larsson, Patrick Alexander Schjøtt Andersen, Emil Byström, Krist V. Gernaey, Ulrich Krühne
Industrial & Engineering Chemistry Research, 56 (2017) 3853-3865