Juan Manuel Fernández García - Academia.edu (original) (raw)
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Papers by Juan Manuel Fernández García
Chemical Engineering and Processing: Process Intensification, 2008
Coalescence next to the dispersion devices depends on the design of the sieve plates, the physica... more Coalescence next to the dispersion devices depends on the design of the sieve plates, the physical properties of the fluids and the gas flow rate across the orifice. Coalescence affects the bubble mean size and the hydrodynamics inside the bubble column determining the efficiency of the gas-liquid mass transfer processes. In this work, the coalescence rate of bubbles generated from two separated orifices has been studied and modeled. Inviscid and viscous fluids have been examined as well as a wide range of orifice configurations. The coalescence of rigid bubbles, generated mainly in viscous fluids, depends only on geometrical considerations. On the other hand, coalescence of deformable bubbles depends on the degree of deformation. Two different approaches have been proposed to predict the coalescence behaviour. First, a mechanistic approach based on the study of the collisions between the growing bubbles, which uses the concept of draining time. Second, a statistical approach, which applies the logistic distribution to the fraction of coalesced bubbles. Typical dimensionless numbers, like the We, Eö or DEF (the deformation number), have been used to quantify the effect of the deformability of the bubbles. Both approaches can explain and predict the degree of coalescence observed in the experimental device.
Chemical Engineering and Processing: Process Intensification, 2008
Coalescence next to the dispersion devices depends on the design of the sieve plates, the physica... more Coalescence next to the dispersion devices depends on the design of the sieve plates, the physical properties of the fluids and the gas flow rate across the orifice. Coalescence affects the bubble mean size and the hydrodynamics inside the bubble column determining the efficiency of the gas-liquid mass transfer processes. In this work, the coalescence rate of bubbles generated from two separated orifices has been studied and modeled. Inviscid and viscous fluids have been examined as well as a wide range of orifice configurations. The coalescence of rigid bubbles, generated mainly in viscous fluids, depends only on geometrical considerations. On the other hand, coalescence of deformable bubbles depends on the degree of deformation. Two different approaches have been proposed to predict the coalescence behaviour. First, a mechanistic approach based on the study of the collisions between the growing bubbles, which uses the concept of draining time. Second, a statistical approach, which applies the logistic distribution to the fraction of coalesced bubbles. Typical dimensionless numbers, like the We, Eö or DEF (the deformation number), have been used to quantify the effect of the deformability of the bubbles. Both approaches can explain and predict the degree of coalescence observed in the experimental device.