Research on flow field and kinematic characteristics of fly ash particles in rotary triboelectrostatic separator.

Rotary triboelectrostatic separator is employed to remove and recycle unburned carbon from fly ash which are main solid wastes of coal-fired power plants. The products after decarburization can be used for building materials, road construction material and other function materials. In previous works, effects of structural parameters and operating parameters on recovery process of fly ash were studied. The present work shows the inlet airflow velocity, rotating angular airflow velocity and co-flow velocity directly affect the airflow filed and motion characteristics of fly ash particles from the analysis of separation process using numerical simulation methods. The average airflow velocity in rotary triboelectrostatic chamber have a trend of first increase, then decline and increase again with the increase of inlet airflow velocity, and it increases with the rotating angular airflow velocity in the selected range. Vortexes appeared on both sides of the inlet and grew bigger with the increase of inlet airflow velocity and rotating angular airflow velocity. Co-flow velocity only affected the airflow in the electrostatic chamber. Moving in the airflow and colliding with friction walls were main motion characteristics of ash particles and carbon particles. The collision numbers were closely related to the net charge from the comparison of simulation and experiment results, it suggested that the net charge of ash particle would increase with the collision numbers. [ABSTRACT FROM AUTHOR]