Helena Sovová
Czechoslovak Academy of Sciences
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Featured researches published by Helena Sovová.
Chemical Engineering Science | 1981
Helena Sovová
Abstract The model of dispersion proposed by Coulaloglou and Tavlarides is compared with published results from experiments in batch stirred tanks. An alternative to this model is developed by introducing a different formula for the efficiency of collisions—the mechanism of coalescence of drops by film drainage is replaced by a mechanism based on the effect of collision impact. Good agreement of the modified model with experimental data is demonstrated and the values of the respective parameters are determined.
Chemical Engineering Science | 1976
Helena Sovová; J. Procházka
Abstract A novel method of measurement of diffusivities of gases in liquids has been proposed consisting of measuring the rate of absorption of a gas into a laminar film of liquid flowing radially over the surface of a horizontal disc. The absorption cell works continuously with recirculation of liquid. The profile of velocities in the liquid film was investigated by photochromic technique and was found to be parabolic. A theoretical relationship has been formulated for the rate of absorption. The measurement of the rate of absorption of CO 2 into water and toluene has shown a good agreement with data from literature. The reproducibility is better than 5%.
Chemical Engineering Science | 1983
Helena Sovová
Abstract A stagewise polydisperse model of the Karr vibrating plate extractor hydrodynamics is presented. It describes the drop size distribution and the dispersed phase hold-up as functions of drop transport, breakage and coalescence. 1 The predicted stationary hold-up profiles and drop size distributions are proved to be in good agreement with the experimental data.
Chemical Engineering Science | 1990
J. Vohradský; Helena Sovová
Abstract The motion of single-solvent drops in water in the countercurrent Karr column with vibrating plates was examined by means of multiple photography. Profiles of mean residence times along the height of the stage were evaluated from repeated experiments. Mean residence times in the stage were compared with the residence times of drops in the absence of plates. The time delay due to vibrating plates is a function of the intensity of vibration and the velocity of the continuous phase. The ratio of the characteristic velocity to the terminal velocity is lower than 1 and diminishes with increasing intensity of vibration, velocity of the continuous phase and drop size.
Chemical Engineering Science | 1986
Helena Sovová; Antonín Havlíček
Abstract Transfer functions relating the holdup to the intensity of plate reciprocation and to the velocity of the dispersed phase were determined from experiments in a 4m high VPE reciprocating plate solvent extraction column. The system under investigation was toluene dispersed in water without mass transfer between the phases. An ultrasonic technique of the on-line local holdup measurement was applied. Transfer functions were of first order, with a time lag and with non-linear parameters. A procedure predicting the values of these parameters from the steady-state holdup equations was developed.
Industrial & Engineering Chemistry Research | 1993
Helena Sovová; Jaroslav Procházka
Collection of Czechoslovak Chemical Communications | 1984
Antonín Havlíček; Helena Sovová
Collection of Czechoslovak Chemical Communications | 1990
Helena Sovová
Collection of Czechoslovak Chemical Communications | 1983
Aleš Heyberger; Helena Sovová; J. Procházka
Collection of Czechoslovak Chemical Communications | 1982
Helena Sovová