ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Prediction of power consumption in mechanically agitated gassed reactor in viscous batch‡

Labík Libor, Moucha Tomáš, J. Rejl František, and Valenz Lukáš

^aDepartment of Chemical Engineering, University of Chemistry and Technology, Prague, Technická 5, 166 28, Prague 6, Czech Republic

E-mail: libor.labik@vscht.cz

Abstract: Transport characteristics such as volumetric mass transfer coefficients, k_La, power input, P, gas hold-up, φ, and mixing time, t_m, are the key parameters in the design of mechanically agitated gas– liquid contactors. For their successful design, values of the key parameters can be estimated using empirical correlations. Power input in this case is very often used as the scale of energy dissipation for other characteristics. Our goal was to propose reliable power input correlations for viscous batch processes, which are widely used in industry. The measurements were carried out in a pilot-plant vessel and also results from a laboratory vessel were used to develop the correlations. Different types of impellers and their combinations were used, including radial, axial, and combined liquid flow impellers. The power input was measured in a multiple-impeller vessel at different impeller frequencies and several gas flow rates. Correlation equations describing the behavior of particular impellers were evaluated. In addition, separate correlations for the bottom and upper sections in the multiple-impeller vessel were presented. These correlations can be used for impeller power prediction in industrial scale vessels under a wide range of operational conditions.

Keywords: power input – viscous batch – multiple-impeller vessel – correlation – gas–liquid

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0229

Chemical Papers 70 (4) 461–469 (2016)