Application of the principles of gas permeability and stochastic particle agitation to predict the pressure loss in slug flow pneumatic conveying systems

This paper focuses on the development and applicability of a single slug or total slug model that combines the concepts of gas permeability through bulk material (Ergunʹs model), particle agitation (kinetic theory) and gas expansion along a conveying pipeline (ideal gas law). Due to the independent development of those three models, a system of three equations with three unknowns can be solved to obtain the pressure loss, particle velocity and gas density along a slug. Calculations were carried out and compared with the experimental data obtained during horizontal slug flow pneumatic conveying of plastic pellets. The effects of the most relevant physical parameters to be input in the prediction model such as slug porosity, stresses, supply air velocity and total slug length are discussed on the basis of experimental and numerical results.