One of the new topics covered in the Technical Workshop at the Cemtech conference and exhibition in Dubai was the optimisation of vertical roller mills (VRMs). Here Dr Clark considers the grinding action of the VRM and the importance of dam ring adjustment and gas flow through the mill. By Dr Michael Clark, UK.
Vertical roller mills (VRMs) have become the equipment of choice for raw and solid fuel grinding in cement factories. Increasingly modern cement plants also use VRMs for cement grinding. However, opportunities for the optimisation of VRMs are less obvious than with ball mills as all processes of grinding, drying, classification and regrinding take place within the body of the mill.
Normal VRM control strategies
Product fineness
The set-up of the VRM does not provide opportunities to take samples to assess the performance of the separator and the recirculating load in the mill, or the progress of size reduction along the grinding path.
