We present a new numerical model of filtration of liquid aerosols on fibrous filters. The main goal of the model is to describe the dependence of pressure drop on time during the nonstationary filtration process. The main difference between the current model and others present in the literature is that it contains very few parameters-in its minimal form only two-and still describes the results of experimental measurements with a very good accuracy. We also estimate the dependence of the parameters of the model on the process conditions (i.e., gas flow velocity and the geometrical parameters of the filter) which enable the use of the presented model to predict the filtration process evolution in any fibrous filters.