Stanisław Wroński

Dynamic filtration in biotechnology

In this paper the effectiveness of separation in different systems of dynamic filtration, both mechanical and crossflow filtration, has been compared. Apart from the filtration rate obtained under comparable conditions the energy demand for these processes has also been compared. The obtained results show that dynamic mechanical filtration can in some cases be more effective than the more commonly used crossflow filtration.

Mass transfer in gas-liquid Couette-Taylor flow reactor

The results of the measurements of mass transfer coe

Mass transfer in gas-liquid Couette-Taylor flow in membrane reactor

cients for the physical (CO /water) and chemical absorption (oxidation of benzaldehye) have been presented. The collected experimental data have been correlated with the energy dissipated in the system. High values of the mass transfer coe

Axial dispersion in packed beds: the effect of particle size non-uniformities

cients, k a, of the order of 10 s have been obtained. 2001 Elsevier Science Ltd. All rights reserved.

Mass transfer model for the film countercurrent flow of two liquid phases in a packed bed column

A concept of membrane CTF (Couette-Taylor flow) reactor applicable to gas-liquid processes has been presented. Its fundamental hydrodynamic and kinetic properties have been discussed. In the experiments high values of the mass transfer coefficients, k L a, of the order of 0.1 s -1 have been obtained and a relatively weak influence of the liquid viscosity on the values of the mass transfer coefficients has been observed. To eliminate moving elements of the reactor, a replacement of the rotor by a static helical ribbon guide which forces the helicoidal flow of the fluid has been proposed for the same operating conditions.

Mass Transfer Modelling in the Couette-Taylor Flow Reactor for the Oxidation Process of Organic Contaminants

Abstract The effect of particle size non-uniformities on axial dispersion coefficients during laminar liquid flow through packed beds has been studied. The investigations were carried out for binary mixtures of particles with diameters d1 = 0.169 mm and d1 = 0.360 mm. A generalized function to determine the increase of the axial dispersion coefficients in non-uniform beds relative to those obtained in uniform beds has been proposed.

Reducing fouling and boundary-layer by application of helical flow in ultrafiltration module employed for radioactive wastes processing

Previously, the film flow of two liquids in a packed bed column was not very often encountered in industrial practice and was therefore not intensively investigated. Now however, the significance of this kind of flow has increased because of the rapid development of column supercritical extraction, where the film flow is frequently observed. In this study, a mass transfer model for the film flow of two liquid phases in a packed bed is proposed. Based on the hydrodynamic considerations under fully developed laminar flow conditions, the mass transfer correlations have been derived. Hydrodynamic predictions have been compared with experimental data on holdup in the literature. Also, correlations proposed for the mass transfer coefficients in both the film and the core phases respectively, have been successfully verified by comparing them with experimental data from the literature.

Toward understanding of two-phase eccentric helical reactor performance

The Couette-Taylor Flow reactor (CTF reactor) is characterised by high values of the mass transfer parameters. Our previous mass transfer investigations revealed high values of the volumetric mass transfer coefficients (of the order of 10-1 s-1) and the specific interfacial area, higher than those obtained in the stirred tanks. The experimental results of benzaldehyde oxidation considered potential application of the CTF reactor in oxidising organic liquids and contaminants. Owing to its tubular construction the CTF reactor is suitable to operate in a continuous process at elevated pressures. In one of the advanced oxidation methods, i.e. the Wet Air Oxidation, some fundamental problems emerge, e.g. how to intensify diffusional mass transfer. In the case of technical apparatus, even when solid catalysts are applied, diffusional factors control the overall process rate. Under such circumstances the CTF reactor is applicable. The mass transfer correlation was proposed as the first step in wet air oxidation modelling.