A significant challenge of modern technology is the design of high-efficiency filters that allow more effective removal of aerosol particles suspended in the air, e.g. micron and submicron oil droplets. Our previous work has proven that aerogel structure deposition on fibre surface is a promising method for post-production improvement of the oil-mist filter performance. In this work, a modification of the previously described method was proposed, consisting in carrying out the process in the flow (semi-batch) regime, i.e. the streams of reagents successively pass through the filter in a self-designed and self-made modification chamber. The effect of the reactant flow rate and the order of reactants (precursor/catalyst or catalyst/precursor solutions) on the mass of deposited aerogel, and thus - also on the filtration efficiency during the removal of oil mist droplets and the pressure drop accompanying the airflow - is presented and described. The possible routes of modification scaling-up are discussed with defined unit operations.