ЧИСЛЕННЫЙ РАСЧЕТ ФИЛЬТРОВАНИЯ СУСПЕНЗИИ НЕНЬЮТОНОВСКОГО ПОВЕДЕНИЯ В НАМЫВНЫХ ФИЛЬТРАХ

Abstract

The research was carried out with the aim of mathematical modeling of the process of filtering finely dispersed non-Newtonian suspensions in intermittent pre-wash filters. The power-law fluid model is used to describe the rheological state of the medium. At the beginning of the filtration cycle, a layer of auxiliary material is washed, which is used as a filtering partition. A finely dispersed suspension during the filtration process forms a second layer, as it grows, the resistance to the flow of the liquid phase increases. The filtration cycle ends after reaching the critical values of pressure or productivity, depending on the operating mode of the device. Filtration equations are written in a cylindrical coordinate system separately for each layer. At the interface between the layers, pressure and velocity jumps arising due to the difference in porosity are taken into account. To calculate the thickness of the formed sediment layer, a differential equation was built. It is shown that the constructed mathematical model can be used to calculate the filtration of suspensions with a linear model of the rheological state, if the passage to the limit is performed. It is also shown that after passing to the limit, the results of the work allow modeling the process of filtering non-Newtonian media in plate-type filters. Numerical calculations are carried out for the filtration mode with a constant speed. The regularities of the effect of equivalent viscosity, the degree of medium nonlinearity, as well as the initial concentration of the dispersed phase on the filtration process were studied. It is shown that with an increase in these parameters, the pressure limit in the apparatus reaches earlier, which will lead to a reduction in the filter cycle time.