Dimensionless Correlation of Liquid-Phase Dispersion Coefficient in Bubble Columns

Abstract

Recently, the authors1} measured the liquid-phase dispersion coefficient in 10 cm and 19 cm I.D. bubble columns with single-nozzle gas spargers using air as the gas and using water and aqueous solutions of methanol and cane sugar as liquids. All the experimental data could be correlated well by the following empirical equation :

Hydrodynamics and Heat Transfer of Baffled and Unbaffled Slurry Bubble Columns

“…The specific gas-liquid interfacial area, a, defined as the surface area available per unit volume of the bubble column, is related to e g and dvs by the following simple relation 718,237: a = 6sg/dvs (101) where dvs, the Sauter mean-bubble diameter, has a mean volume-to-surface ratio such that dvs = Σ Njd i/l Njd|j (102) where ΝΪ is the number of bubbles of class i having the diameter dei-The various correlations recommended for the computation of "a" are listed in Table 2.…”

A Dispersion Model for the Solvent Refined Coal Process

“…Recently the effect of the liquid phase physical properties on the liquid phase longitudinal dispersen coefficient was studied by Hikita and Kikukawa (1975). By using dimensional analysis, these authors obtained the following functional form bubble columns with single-nozzle gas spargers using air as the gas and using water and aqueous solutions of methanol and cane sugar as the liquids, and a superficial gas velocity from 4.3 ~33.8 cm/s, the effect of the dimensionless group PifiT2g/<r on Dl/-Dt3S was determined to be negligible.…”

Individual longitudinal dispersion coefficients of two immiscible liquids in bubble columns

“…(-) Fit according to eq 2 with Ec = 0.012 m2/s. Key: (--) Baird and Rice (1975); (-) air-water, Hikita and Kikukawa (1975); (-• -) air-kerosine, Hikita and Kikukawa (1975).…”

“…Thus, the reproducible data of the dispersion coefficients were difficult to measure at such low superficial gas velocities in the run with Lc = 0.528 m. From the results for the higher superficial gas velocity, however, the dispersion coefficients Ec and ED of both liquids may be regarded as independent of the clear liquid height Lc. Therefore, all other experiments were performed at a clear liquid height of 1.12 m. In this figure are also shown the values of the liquid-phase dispersion coefficient predicted from the correlations of Baird and Rice (1975) and of Hikita and Kikukawa (1975) for a gas-single liquid system. The latter correlation allows for the effect of the physical properties of the liquid, so that the dispersion coefficients were calculated by using the individual physical properties of kerosine and water.…”

“…situation means that a very small amount of existing tiny liquid drops move without any interference among them and with no slip velocity from the continuous liquid. On the other hand, the correlation of eq 10 makes allowance for the fact that Pec should reduce to that for the liquidphase longitudinal dispersion in conventional gas-single liquid bubble columns (Hikita and Kikukawa, 1975) (Mo003)(Fr) Pec =---(13) 0.037 + 0.188(Pr°•72) when dispersed liquid is absent (0 -» 0). The coefficients and powers in eq 10 and 11 were determined by the simplex method.…”