This paper is devoted to the problem of developing the newly efficient method for modeling the aggregation processes in polydisperse systems, without limitation of considering only binary collisions. The submitted method is an extension of the method previously developed by the authors for the case of a three-dimensional stochastic lattice. Such an extension increases the practical significance and reliability of the simulation results. The deals with the results of a numerical experiment conducted to study the kinetics of the aggregation process occurring in a dispersed system flowing through a 3D tubular reactor based on the discrete-event simulation paradigm (DES). The model is based on the mathematical apparatus of a random walk on mathematical lattices. As shown in this work, this approach allows removing the problem linked to accounting the effect of many-particles collisions, and it allows reducing the problem of calculating the aggregation kernels in kinetic equations to taking into account the hierarchy of characteristic times of the various stages of the aggregation process.