The Method of Calculations of the Sedimentation Efficiencyin Tanks with Lamella PacketsWłodzimierz P. KowalskiAGH – University of Science and Technology, Cracow, Poland, Faculty of Mechanical Engineeringand Robotics, al. Mickiewicza 30, 30-059 Kraków, e-mail: wkowalsk@agh.edu.pl(Received May 12, 2004; revised July 02, 2004)AbstractThe paper outlines a method to determine the sedimentation efficiency in modernizedtanks with incorporated lamella packets. The method takes into account the propertiesof the suspension (density, viscosity, solid phase distribution) and tank designparameters – flow intensity and settling surface. Several types of grain size distributionsare considered: the log-normal distribution and generalised gamma distribution.The sedimentation efficiency is investigated in relation to the ratio of tank fillingwith lamella packets. The lamella ring width in a round Dorr clarifier is taken asan example. The analysis is performed by way of computer simulations. The appliedcalculation procedure was extensively verified in laboratory tests, pilot tests andindustrial-scale tests (Kowalski 2000) and the obtained results were regarded as satisfactory.The error involved in calculations of the sedimentation efficiency is less than0.05 when the efficiency value exceeds 0.8.
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