New insight into the kinetics of particle resuspension process

BENITO, J. G.; R.O. UÑAC; A. M. VIDALES; I. IPPOLITO

Saint Louis

Conferencia; Xth International Aerosol Conference; 2018

New insight into the kinetics of particle resuspension processJ.G. Benito (1), R.O. Uñac (1), A.M. Vidales (1) and I. Ippolito (2)(1) INFAP, CONICET, Departamento de Física, Facultad de Ciencias Físico Matemáticas y Naturales, Universidad Nacional de San Luis, Ejército de los Andes 950, D5700HHW, San Luis, Argentina.(2) Grupo de Medios Porosos, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, 1063, Buenos Aires, Argentina.Particle resuspension has been subject of special attention for researchers since many decades. This phenomenon is present in a wide range of fields, such as resuspension of airborne particles, reentrainment of sediments, human health, filtration systems, food industry and mining production. In particle resuspension phenomena, experimental and simulation evidence demonstrate that air flow acceleration increases the velocity range needed for all the resuspension process. Nevertheless, this process becomes faster when acceleration increases. Using a simple Monte Carlo model and, by analogy with the process of thermal desorption of molecules from surfaces, we are able to reproduce experimental data to analyze the main kinetic parameters of the problem. In our simulations, a monolayer of spherical particles are attached to the surface through an adhesion force that follows a Lognormal distribution and a Gaussian distribution is assumed for the aerodynamic forces. The stochastic process used for resuspension is based on the evaluation of probabilities depending on the ratio between the moments of the forces acting on each particle and using a Metropolis function. To better understand the behavior related to the air flow acceleration used, we present a Kinetic Programmed Resuspension methodology, KPR, based on the analogy with the Temperature Programmed Desorption (TPD) technique. This technique enables us to obtain, through simple calculations, a transcendental equation that relates the friction velocity with the air flow acceleration and others particle-substrate constants.Our numerical results are in agreement with the increase of particle rate with acceleration. Besides, the air velocity for maximum flow rate results to be higher as acceleration increases. Finally, the KPR technique results in a potential tool which allows us obtaining particle-surface system constants by performing numerous repetitions of experiments for different values of air acceleration. This possible application could be devoted to find those parameters typically unknown in an experimental scenario.