The aim of the research is to develop a method for determine the optimal composition of polymer-concrete filtering element (PCFE) providing required parameters of water quality for drip irrigation. During the study it was established that the main parameters facilitating effective treatment of natural waters through PCFE were the size and number of pore canals which, by-turn, were in the direct relation to the quantity of polymer binder. As a result of the study, the authors developed the model for determine the composition of PCFE based on classical proposition of pore medium described in Slichter physical model. The model of filtering element is consisted of filler (fractionated coal combustion by-products) and polymer binder. According to the given model, pore medium represents the set of filler grains assuming to be of equal size, spherical form packed hexagonally that is each grain has 12 points of contact with other grains providing the maximum density of ultimate material. By-turn, polymer binder provides immobility of the filtering element structure forming branchy net of perforated pore canals. While modeling polymer-concrete plate, following assumptions were embedded: filler fraction composition is poly-dispersed; fractions assumed to be of a regular spherical shape; the thickness of the film of polymer binder covering filler grains may be not equal for all grains; the part of polymer binder fills pore canals giving them a cylindrical shape. The developed model enables to define required volume of polymer binder under the given diameters of particles to provide branchy net of perforated pore canals, by which the filtration of natural water for drip irrigation will occur.
Keywords: mathematical model, drip irrigation, filtering element, pore medium, Slichter physical model, thickness of binder, coal combustion by-products.
