Model of transient aerosol particle deposition in fibrous media with dendritic pattern
TL;DR: In this article, a generalized version of the particle dendrite growth model was developed, and the use and behavior of this model was demonstrated in the simple case of deposition by pure interception.
Abstract: When a suspension of fine solid particles in a gaseous medium flows through a fibrous filter, particles deposit on the fibers forming chainlike agglomerates known as dendrites. This deposition pattern is responsible for the intrinsically transient behavior of the filter, leading to drastic increases of the filtration efficiency and of the pressure drop. Related phenomena are observed when aerosols flow through other types of porous media (for example, granular beds), or next to duct walls, around immersed objects, etc. A theoretical model of the particle dendrite growth was proposed recently by Payatakes and Tien. Here a revised and generalized version of that model is developed. The following major revisions are made: allowance is made for collisions with a particle in a given dendrite layer that lead to retension in the same layer, radial as well as angular contributions to deposition are considered, and the dendrite layer adjacent to the collector is allowed to contain more than one particle. These changes lead to a substantially more realistic theoretical model. Expressions for the transient behavior of a filter of differential thickness are obtained, based entirely on first principles. These, as it has been shown in a previous publication, can be used to predict the dynamic behavior of a macroscopic fibrous filter. The use and behavior of this model is demonstrated in the simple case of deposition by pure interception. The present treatment of deposition by pure interception is more rigorous than and supersedes that adopted in previous works.
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More filters
TL;DR: In this paper, a network model was developed to simulate the flow of emulsions and solid particles through porous media, and particle deposition due to direct interception, as well pore plugging by straining were accounted for in the model.
Abstract: A network model has been developed to simulate the flow of emulsions and solid particles through porous media. Particle deposition due to direct interception, as well pore plugging by straining are accounted for in the model. The effects of two important factors-the ratio of particle size to pore size, and the fluid velocity-on particle deposition are also investigated. The strength of the model lies in its ability to predict accurately effluent concentration profiles, permeability changes occurring during deep bed filtration, and the evolution of the filter coefficient with time. Model predictions for different particle and pore size distributions of both solid and emulsion particles are in agreement with experimental data.
182 citations
TL;DR: In this article, a simplified filtration model was proposed to describe the flow of stable, dilute emulsions in unconsolidated porous media, where emulsion drops are captured in pores by straining and interception and, thus, reduce the overall permeability.
157 citations
TL;DR: In this paper, a new model was developed to predict the clogging behavior of high-efficiency particulate air filters, taking into account the heterogeneous deposit of particles inside the filter medium.
116 citations
TL;DR: In this article, a new theory based on deep-bed filtration concepts was proposed to describe the flow of dilute, stable emulsions in underground porous media and quantitatively test the proposed theory against experimental data.
97 citations
TL;DR: In this paper, the growing process of particle dendrites on a fiber and the time dependency of a single fiber collection efficiency under dust loaded conditions were studied using Monte Carlo simulation technique.
79 citations