Mathematical modelling of biofilter’s temperature regimes

Abstract

The dependence of the filter efficiency on its charge height (0,15–0,75 m) with different initial pollutant concentrations and at different charge temperatures (7, 14, 28 0C) was modelled. Mathematical modelling was carried out on the dependence of the filter efficiency on the speed of the passing air (up to 2 m/s) with different initial pollutant concentrations and different temperatures maintained in the charge (7, 14, 28 0C). Similar to experimental tests, the increase in the charge height (from 0,15 to 0,75 m) results in the increase in cleaning efficiency. For example, when the temperature of 28 0C is maintained in the filter and the air is being cleaned of xylene (with its initial concentration of 49 mg/m3), the efficiency of removal of xylene starting with the height of the charge equal to 0,45 m is 50,43%, starting with the height of 0,75 m it is 63,9%. These results confirm the results of the experimental tests showing that the increase in the passing air flow speed (up to 2 m/s) results in the decreased efficiency of air cleaning. Accordingly, when the temperature of 7 0C is maintained in the filter and the air is being cleaned of butanol (with its initial concentration of 51 mg/m3), with the speed of the passing air increased from 0,4 to 2 m/s, air cleaning efficiency significantly decreases (from 74 to 62%). Thus, the obtained mathematical expression of efficiency will in future facilitate theoretical calculations, choice of appropriate device parameters and receive maximum air cleaning efficiency.