Overall dispersed side volumetric mass transfer coefficients for protein and amino acids were measured in continuous countercurrent PEG4000/KHP aqueous two-phase systems in a 57mm I.D. packed extraction column. A mode...Overall dispersed side volumetric mass transfer coefficients for protein and amino acids were measured in continuous countercurrent PEG4000/KHP aqueous two-phase systems in a 57mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The average relative deviation between calculated values and experimental data ranges from 8% to 14%.展开更多
Hydrodynamics and mass transfer experiments were carried out in a 0.1m diameter extraction column with a new type (FG) stack packing developed recently in our laboratory.The working systems used were n-Butano1/Succini...Hydrodynamics and mass transfer experiments were carried out in a 0.1m diameter extraction column with a new type (FG) stack packing developed recently in our laboratory.The working systems used were n-Butano1/Succinic acid/water with low interfacial tension of 1.50×10-3N·m-1 and 30% TBP (Kerosene)/Acetic acid/water with interfacial tension of 10.0×10-3N· m-1. Experimental results obtained indicated that (FG) stack packed extraction column was proved to possess high throughput capacity and excellent mass transfer efficiency. Replacing rotary discs with FG packings in a lube furfural extraction tower was quite success with significant economical benefits being claimed.展开更多
Correlations will be presented to describe liquid hold up, loading and flooding capacity, volumetric mass transfer coefficients on liquid and gas or vapour phase and the pressure drop as a basis for computing packed c...Correlations will be presented to describe liquid hold up, loading and flooding capacity, volumetric mass transfer coefficients on liquid and gas or vapour phase and the pressure drop as a basis for computing packed columns, dumped and regular as well, including the influence of end effects on scaling. The relationships are found on a sound physical and mathematical basis and their validity were confirmed by experimental investigations of many packings; some of them were selected to be considered in this work.展开更多
Air was fed into a packed extraction column to increase turbulence,enhance liquid droplet dispersion and surface renewal,and thus raise mass transfer area.This led to improvement of liquid-liquid contact and mass tran...Air was fed into a packed extraction column to increase turbulence,enhance liquid droplet dispersion and surface renewal,and thus raise mass transfer area.This led to improvement of liquid-liquid contact and mass transfer.The experiments on hydrodynamics and mass transfer were carried out with air-kerosene (benzoic acid)-water system, and the effect of air agitation was investigated.It is clear from the results that the air hold-up ,dispersed phases hold-up and mass transfer coefficient increase and flooding velocity goes down while increasing superficial air velocity.The over-agitation of air can cause over-dispersion and emulsification of the dispersed phase,deterioration of mass transfer performance,and even flooding.Packing helps to break up the droplet of dispersed phase and can effectively prevent the liquid from longitudinal mixing in extraction column,so the mass transfer performance of packed column is far better than that of non-packed.展开更多
基金Supported by the National Natural Science Foundation of China.
文摘Overall dispersed side volumetric mass transfer coefficients for protein and amino acids were measured in continuous countercurrent PEG4000/KHP aqueous two-phase systems in a 57mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The average relative deviation between calculated values and experimental data ranges from 8% to 14%.
基金Supported by the National Natural Science Fundation of China.
文摘Hydrodynamics and mass transfer experiments were carried out in a 0.1m diameter extraction column with a new type (FG) stack packing developed recently in our laboratory.The working systems used were n-Butano1/Succinic acid/water with low interfacial tension of 1.50×10-3N·m-1 and 30% TBP (Kerosene)/Acetic acid/water with interfacial tension of 10.0×10-3N· m-1. Experimental results obtained indicated that (FG) stack packed extraction column was proved to possess high throughput capacity and excellent mass transfer efficiency. Replacing rotary discs with FG packings in a lube furfural extraction tower was quite success with significant economical benefits being claimed.
文摘Correlations will be presented to describe liquid hold up, loading and flooding capacity, volumetric mass transfer coefficients on liquid and gas or vapour phase and the pressure drop as a basis for computing packed columns, dumped and regular as well, including the influence of end effects on scaling. The relationships are found on a sound physical and mathematical basis and their validity were confirmed by experimental investigations of many packings; some of them were selected to be considered in this work.
文摘Air was fed into a packed extraction column to increase turbulence,enhance liquid droplet dispersion and surface renewal,and thus raise mass transfer area.This led to improvement of liquid-liquid contact and mass transfer.The experiments on hydrodynamics and mass transfer were carried out with air-kerosene (benzoic acid)-water system, and the effect of air agitation was investigated.It is clear from the results that the air hold-up ,dispersed phases hold-up and mass transfer coefficient increase and flooding velocity goes down while increasing superficial air velocity.The over-agitation of air can cause over-dispersion and emulsification of the dispersed phase,deterioration of mass transfer performance,and even flooding.Packing helps to break up the droplet of dispersed phase and can effectively prevent the liquid from longitudinal mixing in extraction column,so the mass transfer performance of packed column is far better than that of non-packed.
