Effect of Process Parameters on Oil-in-Water Emulsion Droplet Size and Distribution in Swirl Flow Membrane Emulsification
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 2018
Swirl flow membrane emulsification is a very high disperse phase flux method for high throughput ... more Swirl flow membrane emulsification is a very high disperse phase flux method for high throughput production of emulsions. The extremely vigorous, turbulent flow eddies generated exert an extremely high radial drag force on the membrane wall, which prevents the transition of droplet formation from the dripping regime to the continuous out flow regime, at extremely high disperse flux emulsion production. In the present study, the effects of surfactant, disperse phase flux, viscosity, and swirl flow velocity on the mean droplet diameter (D50) and droplet size distribution coefficient (span) of an oil-in-water (O/W) emulsion are analyzed. The results indicated that highly monodispersed emulsions could be prepared at very high dispersed phase uses of 2.0 to 15.6 m 3 m-2 h-1. The most monodispersed emulsions produced were of D50 of 33.4 µm and of span of 0.24, obtained at various process conditions. The emulsion D50 and corresponding span decreased with swirl flow velocity until the critical velocity of 8.5 m/s, beyond which the D50 decreased further while its corresponding span increased slightly. The increase of the dispersed phase viscosity resulted in an increase of the emulsion D50, while the increase in viscosity ratio in respect to the continuous phase viscosity led to a decrease in D50. The disperse flux had no significant effect on D50 until the critical disperse flux of 11.7 m 3 m-2 h-1 , beyond which the inertial force became the dominant force of droplet formation and the D50 increased drastically; although it could be counterbalanced at high surfactant concentration and at higher swirl flow velocities.
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where functional hydrogels are playing vital roles. The current study is mainly
focused on the synthesis of Pectin–Acrylamide–Vinyl phosphonic acid hydrogels
(Pectin–AAm–VPA) and the selective adsorption of metal ions from the solution of
multielement. The hydrogels were prepared by applying gamma radiation of different
doses ranging from 5 to 50 kGy where 20 kGy was optimized based on the gel
content and the equilibrium swelling analysis. The functional groups of the hydrogel
were identified by FTIR spectroscopic analysis. Thermal properties—glass transition
and melting temperature of the gel were investigated by DSC thermogram. It
was an amazing finding that the hydrogels show selective adsorption toward Al, Fe,
Ga, In, Mo, and Bi metal ions from the solution containing 27 metal ions. The surface
of the gels before and after metal adsorption was inspected using SEM supported
by EDS and confirmed the selective adsorption. Metal ions were desorbed
successfully in 5% nitric acid. Finally, it can be stated that the Pectin–AAm–VPA
hydrogels can effectively be used for selective adsorption of Al, Fe, Ga, In, Mo, and
Bi metal ions from the multielement solutions.
Several experiments and research using numerical analysis have been reported, however, there are still many unknown physical phenomena that need to be studied, in order to optimize the design and improve the efficiency of turbomachines, especially those installed on hydrogen-powered fuel cell electric vehicles (FCEVs). In this study, the 3-dimensional vortex structures were analyzed using the critical-point theory and the probabilistic definitions, for an air supply device mounted on the commercial hydrogen FCEVs. The behavior of the complex 3-dimensional vortex structures at the design flow rate and low flow rate were elucidated. A tip leakage vortex was observed to develop at the leading edge of the main blade at all flow rates, which caused interference to the splitter blade. At 60% of the design flow rate, a vortex breakdown occurred at the tip leakage vortex near the leading edge of the main blade, and a reverse flow at 50% chord length of the main blade’s suction surface. The boundary layer which developed at the leading edge of the main blade’s suction surface at all flow rates led to the creation of a hub separation vortex by interfering with the boundary layer developed at the hub surface as a result of the centrifugal force. In addition, the boundary layer developed at the hub and shroud surface created a horseshoe vortex as it moved downstream and interfered with the leading edge of the main blade and splitter blade. It was confirmed that the behavior of the tip leakage, hub separation, and horseshoe vortex structures determined the aerodynamic performance of the centrifugal compressor. The average pressure difference improved by 1.47% of the entire flow rate after optimizing the compressor design.
where functional hydrogels are playing vital roles. The current study is mainly
focused on the synthesis of Pectin–Acrylamide–Vinyl phosphonic acid hydrogels
(Pectin–AAm–VPA) and the selective adsorption of metal ions from the solution of
multielement. The hydrogels were prepared by applying gamma radiation of different
doses ranging from 5 to 50 kGy where 20 kGy was optimized based on the gel
content and the equilibrium swelling analysis. The functional groups of the hydrogel
were identified by FTIR spectroscopic analysis. Thermal properties—glass transition
and melting temperature of the gel were investigated by DSC thermogram. It
was an amazing finding that the hydrogels show selective adsorption toward Al, Fe,
Ga, In, Mo, and Bi metal ions from the solution containing 27 metal ions. The surface
of the gels before and after metal adsorption was inspected using SEM supported
by EDS and confirmed the selective adsorption. Metal ions were desorbed
successfully in 5% nitric acid. Finally, it can be stated that the Pectin–AAm–VPA
hydrogels can effectively be used for selective adsorption of Al, Fe, Ga, In, Mo, and
Bi metal ions from the multielement solutions.
Several experiments and research using numerical analysis have been reported, however, there are still many unknown physical phenomena that need to be studied, in order to optimize the design and improve the efficiency of turbomachines, especially those installed on hydrogen-powered fuel cell electric vehicles (FCEVs). In this study, the 3-dimensional vortex structures were analyzed using the critical-point theory and the probabilistic definitions, for an air supply device mounted on the commercial hydrogen FCEVs. The behavior of the complex 3-dimensional vortex structures at the design flow rate and low flow rate were elucidated. A tip leakage vortex was observed to develop at the leading edge of the main blade at all flow rates, which caused interference to the splitter blade. At 60% of the design flow rate, a vortex breakdown occurred at the tip leakage vortex near the leading edge of the main blade, and a reverse flow at 50% chord length of the main blade’s suction surface. The boundary layer which developed at the leading edge of the main blade’s suction surface at all flow rates led to the creation of a hub separation vortex by interfering with the boundary layer developed at the hub surface as a result of the centrifugal force. In addition, the boundary layer developed at the hub and shroud surface created a horseshoe vortex as it moved downstream and interfered with the leading edge of the main blade and splitter blade. It was confirmed that the behavior of the tip leakage, hub separation, and horseshoe vortex structures determined the aerodynamic performance of the centrifugal compressor. The average pressure difference improved by 1.47% of the entire flow rate after optimizing the compressor design.