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

Effects of vessel baffling on the drawdown of floating solids

Joanna Karcz and Beata Mackiewicz

Department of Chemical Engineering, Szczecin University of Technology, al. Piastow 42, PL-71 065 Szczecin, Poland

E-mail: joanka@ps.pl

Received: 5 May 2008  Revised: 10 October 2008  Accepted: 14 October 2008

Abstract: The effects of baffling of an agitated vessel on the production of floating particles suspension are presented in this paper. Critical agitator speed, needed for particles dispersion in a liquid agitated in a vessel of the inner diameter of 0.295 m, was determined. The just drawdown agitator speeds were defined analogously to the Zwietering criterion. Specific agitation energy was calculated from the power consumption experimental data obtained by means of the strain gauge method. The experiments were carried out for twelve configurations of the baffles differing in number, length and their arrangement in the vessels. The following high-speed impellers were used: up- and downpumping six blade pitched blade turbines, Rushton turbine, and propeller. The impeller was located in the vessel in the height equal to two-thirds or one-third of the vessel diameter from the bottom of the vessel. The results were described in the form of a dimensionless equation.

Keywords: agitation - floating particles - baffling

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-009-0011-0

Chemical Papers 63 (2) 164–171 (2009)