An assessment of steady-state conditions in single slug horizontal pneumatic conveying

This study used a 3D coupled CFD–DEM model to assess how slugs tend towards steady state in single slug horizontal pneumatic conveying.Initial slug length,inlet velocity and initial stationary layer fractions were systematically varied for a total of 72 simulations.Previously made observation that slugs tend towards a steady state was confirmed via a theoretical derivation.The derivation shows that slugs move towards their steady state lengths exponentially.This allowed for a calculation of a characteristic time scale which is a measure of how quickly a slug tends towards the steady state.The theoretical estimate which is a function of slug porosity,steady length,velocity and stationary layer fraction has good agreement with simulated results.A link between steady slug length and solids loading ratio was also shown.