Theoretical analysis of aqueous suspension clarification on two- and three-flow rapid filters

ABSTRACT Mathematical problems of the detachment filtration under linear mass-exchange kinetics and variable impurity concentration are formulated and exactly solved with respect to three schemes of aqueous suspension feeding into the rapid filter media. Mass-exchange coefficients are considered as functions of the filtration rate. The permeability of the medium is taken into account depending on the volume of deposited suspension particles. The sets of dependencies for the prediction of changes over time and along height in the concentrations of suspended and deposited suspension particles, and head losses are presented. The technological modeling of suspension clarification is performed, and the dependences of the technological times, mainly filter run duration, on flow rates and length of filtration flows, absorption capacity of the bed for two varieties of two-flow filter, as well as three-flow filter, are derived. As a result of comparative analysis of their and single-flow filter operation, high efficiency of splitting the initial flow into components with their subsequent feeding through different feed boundaries is shown. At the use of well-adsorbing filtering material and considerable initial content of suspended matter due to the arrangement of multi-flow filtration, it is realistic to increase the time of filter run twice or more.