ABSTRACT
However, the estimation of Nmix after Equations (2)– (3) is no more than a coarse description of mechanics in the drum, since parameters like loading and particle size, which may affect the mixing number by influence on the mixing regime, are neglected. Indeed, Ding et al. (2002) reported that the mixing in a rolling bed is rather related to the number of bed revolutions than to the number of drum revolutions. The bed revolution frequency depends on the drum’s rotational frequency and the loading of solids in the drum. Therefore, the mentioned authors proposed to build the Froude number – in this case Fr′ – with the bed rotational frequency, n′, for calculating Nmix.
