A case study on energy and exergy analyses for an industrial-scale vertical roller mill assisted grinding in cement plant

In this study, the analyses of energy and exergy were implemented for an industrial-scale vertical roller mill (VRM) of Kerman Momtazan Cement Company (KMCC) of Iran. The energy and exergy analyses demonstrated the first law efficiency of the VRM is 62.1%, while the second law efficiency of the VRM is 34.6%. Comparing to the widely applied ball milling, the second law efficiency is 16.4% higher for the VRM than the ball mill. Results also showed when the classifier rotor speed increases from 53 to 65 rpm, the particle size of the product decreases from P-90 mu m = 18.2% to P-90 mu m = 10.8%, but the power consumption of the VRM unit increases from 19.7 to 22.3 kWh/t of raw materials. Finally, the power consumption of the VRM unit compared with 14 raw mill units around Iran and the international best available technology (IBAT). The results demonstrated that the VRM unit consumes around 81% (9.75 kWh/t of raw materials), and 36% (5.8 kWh/t of raw materials) more energy to grind raw material than the IBAT unit and domestic best raw mill (DBRM), respectively. (c) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Automated summary

This study conducted energy and exergy analyses on an industrial-scale vertical roller mill in Iran, showing higher efficiency compared to ball milling. Increasing classifier rotor speed decreased product particle size but increased power consumption. Comparisons with other mill units revealed the VRM consumed more energy than the best available technologies.