SIMULATION OF DEEP FILTER PERFORMANCE FOR OPTIMUM DESIGN

This paper describes the calibration and the verification of the previ ously proposed filtration model (UF model) with several sets of experi mental data obtained with various operating conditions using alum floc s. The model was improved by including a simplified interpore floccula tion equation that deals with the growth of flocs flowing through filt er pore channels, in order to compensate for differences between calcu lated and experimental results in a deeper bed. The improved filtratio n model (UF-PF model) successfully describes a breakthrough curve and a head loss buildup of the filtration process, The variations of remov al efficiency and head loss during the filtration process, for various sand grain sizes, filtration velocities, and depths of filter bed, ca n be predicted by means of numerical simulations of the proposed filtr ation equations with the parameters relating to flee properties, The o ptimum operational design which provides a maximum filtrate production during a filter run and its search algorithms, is also discussed for uniform and dual layer fillers by using numerical simulations of the U F-PF model. The design variables considered are grain sizes, filter la yer depths and flow rates,