Abstract
Technologies of reduction in power consumption for vertical roller mills have been developed using fundamental classification test devices and Computational Fluid Dynamics, and the effect on power reduction was evaluated using a pilot scale mill, grinding capacity of which is 2t/h. In order to suppress needless recirculation of fine particles in the mill, which causes over-grinding, performance of the primary classification by gravity force and the secondary classification by centrifugal force was improved. For the primary classification portion, a new rotating nozzle ring with reverse swirling flow, which can achieve sharp classification, was developed. For the secondary classification, a new rotary classifier with a deflector ring and a louver separator was developed. Results of the pilot scale mill tests showed that the power consumption of a latest mill applying the developed technologies was approximately 20% lower than that of the conventional one.
