Hydraulic Properties of Froth Layer on a Perforated Plate

This paper deals with the comparison of gas-liquid holdup and froth height on a perforated plate under various operational conditions such as liquid stagnant, cocurrent, countercurrent and crosscurrent gas-liquid flow system. Tendency to foam is remarkable in countercurrent and crosscurrent flow system. The crosscurrent flow system is suitable for the operation of mass transfer from the point of view of gas-liquid holdup

Treatment of Chlorinated Compounds by Solvent Sublation

Removal of chlorinated compound from an aqueous solution has been studied using solvent sublation. Solvent sublation is one among the several adsorptive bubble separation techniques wherein a hydrophobic compound is levitated on a bubble surface to the top of an aqueous column where they encounter a solvent layer to which the material is transferred as the bubbles move through the solvent layer. A model for the removal mechanism of the chlorinated compounds from aqueous solution was constructed. Removal rate constants for air stripping and for solvent sublation respectively are possible to calculate from the model's equations. The experiments were conducted on a laboratory batch scale using the 0.1m inner diameter bubble column. Bubbles were generated from the perforated plate. The chlorinated compound is dichrolomethane. The solvent layer is kerosine. Dichrolometane was removed at high efficiency by solvent sublation as compared with conventional air stripping, The removal rate constant from the model was compared with experimental result. The mass adsorbed on the bubble surface of 8 types of chlorinated compounds were assumed by the measurements of surface tension. The removal rate constants of these chlorinated compounds, for solvent sublation or for air stripping, are calculated from model equations using the linear adsorption constant

Size of Bubbles and Gas Holdup in Bubble Columns

Bubble columns are extensively used in the chemical industry. This paper evaluates the present state of the art on the size of bubbles from a sieve plate and gas holdup, mainly on the basis of the results of the authors, including previous ones. The size of bubbles formed from a sieve plate has an insignificant effect of chamber volume, and gas holdup shows some different behavior, depending on the hole diameter to liquid depth

Estimation of Gas Holdup in Three-phase Fluidized Bed Containing Small or Low Density Particles

A mechanistic model based on the drift line created by a spherical bubble passing through a liquid is developed to predict the gas holdup in gas-liquid-solid three-phase fluidized beds containing small or low density particles. In the model development, the drift line calculated from stream function for the three-dimensional case is used to predict the mean liquid rise path in the bubble street. The gas holdup can be estimated from the mean bubble rise velocity obtained by the sum of the following : the single bubble rise velocity, the mean liquid velocity calculated from the mean liquid rise path, the gas velocity in the bubble street, and the liquid velocity. Agreement between the calculated and measured values of εg is fairly good using the correction factor. Also agreement of the calculated values of εg with the measurements in the bubble column is good using a constant correction factor of around 0.7

A New Method for the Measurement of Gas Holdup in Solid-Suspended Bubble Columns

A method for the measurement for gas holdup in gas-liquid-solid multiphase devices is developed. The method depends on measurements of hydrostatic pressuress in the three-phase dispersion followed by interruption of gas flow and solids and liquid holdups without gas flow