Operational results of vertical mill conversions

An innovative concept has been developed to optimize internal gas velocities of vertical roller mills and, thereby, result in significant power savings. This method for converting existing vertical mills results in higher grinding efficiencies through the conversion of traditional static and dynamic classifiers to a high efficiency, custom designed, cage-type separator design. Since 1998, over 100 vertical mills have been modified using this concept. This paper briefly reviews the innovative concepts and presents the results of two conversions, including the first raw mill so converted in the United States.