TY - JOUR
T1 - Calculation procedure for flooding in packed columns using a channel model
AU - Brunazzi, Elisabetta
AU - Macías-Salinas, Ricardo
AU - Viva, Aurora
N1 - Funding Information:
We acknowledge the financial support provided by the European Commission within the 6th Framework Programme, Project ‘‘INSERT—Integrating Separation and Reaction Technologies,’’ Contract No: NMP2-CT-2003-505862. One of the authors (R. M.-S.) gratefully acknowledges the Universitá di Pisa and the Instituto Politécnico Nacional for providing financial support for this work.
PY - 2009
Y1 - 2009
N2 - The combined effect of a channel-based approach for dry pressure drop and the Buchanan equation for wet pressure drop in packed beds has been numerically evaluated within the flooding region. The flooding point is an important design parameter since it establishes the maximum hydrodynamic capacity at which a packed column can operate. Upon analyzing the aforementioned approach, it was found that the usual practice of fixing a "reasonable" wet pressure drop at the flooding point (e.g., 1025 Pa/m) may not yield the correct flooding velocity of the gas, particularly at higher liquid loads. In fact, numerical evaluations of the aforementioned model showed a rather "retrograde" non-monotonic behavior of pressure drop with respect to the f factor of the gas near flooding at different liquid loads. A calculation procedure was therefore devised in this work to correctly compute the flooding point for a given liquid load when using the aforementioned modeling approach. Interestingly, it was found that the correct flooding velocity can be directly computed from liquid holdup below the gas loading point. To illustrate the use of the procedure, maximum capacity calculations were performed for a well-known random packing, a conventional structured packing, and a novel catalytic structured packing.
AB - The combined effect of a channel-based approach for dry pressure drop and the Buchanan equation for wet pressure drop in packed beds has been numerically evaluated within the flooding region. The flooding point is an important design parameter since it establishes the maximum hydrodynamic capacity at which a packed column can operate. Upon analyzing the aforementioned approach, it was found that the usual practice of fixing a "reasonable" wet pressure drop at the flooding point (e.g., 1025 Pa/m) may not yield the correct flooding velocity of the gas, particularly at higher liquid loads. In fact, numerical evaluations of the aforementioned model showed a rather "retrograde" non-monotonic behavior of pressure drop with respect to the f factor of the gas near flooding at different liquid loads. A calculation procedure was therefore devised in this work to correctly compute the flooding point for a given liquid load when using the aforementioned modeling approach. Interestingly, it was found that the correct flooding velocity can be directly computed from liquid holdup below the gas loading point. To illustrate the use of the procedure, maximum capacity calculations were performed for a well-known random packing, a conventional structured packing, and a novel catalytic structured packing.
KW - Channel model
KW - Flooding
KW - Packed columns
KW - Pressure drop
UR - http://www.scopus.com/inward/record.url?scp=55849107387&partnerID=8YFLogxK
U2 - 10.1080/00986440802359402
DO - 10.1080/00986440802359402
M3 - Artículo
SN - 0098-6445
VL - 196
SP - 330
EP - 341
JO - Chemical Engineering Communications
JF - Chemical Engineering Communications
IS - 3
ER -