Eulerian-Lagrangian simulation of wood flour and wind distribution during the impulse-cyclone airflow drying process

Abstract

To improve the particle transport computational fluid dynamics models of impulse-cyclone airflow drying systems, a Eulerian-Lagrangian discrete particle model (commercial code ANSYS Fluent 2019 R1) was extended to describe the temperature field, airflow velocity field, and particle distribution in the impulse and cyclone dryers. The results showed that the velocity of the airflow considerably changed after wood flour was added into the system, with an approximate velocity difference between the particles and airflow of 2 m/s. An increased feed rate led to a backflow area at the bottom of the cyclone dryer, which caused reflux and a long residence time of the wood flour in and near the cyclone dryer. By comparing the calculated temperature, velocity, and time curves with the measured temperature and velocity sensor values, the error between the simulated value and the experimental value was only approximately 15%. The current work verifies that the Eulerian-Lagrangian discrete particle model of the impulse-cyclone airflow drying process established via the computational fluid dynamics simulation method was effective. The conclusion provides a reliable theoretical basis for the technological design of impulse-cyclone airflow drying systems, thus providing a way to optimize the structure of impulse-cyclone airflow drying systems in the future.