2014 Volume 22 Issue 2 Pages 57-64
Vertical mills are used to crush fuel for coal fired power plants and to crush limestone to make cement. These vertical mills experience uneven wear during use, so especially at large plants, on-site maintenance often includes welded hardfacing. Because of the high hardness of the hardfacing material, however,the final hardfacing step, which is the finish grinding process, is extremely difficult. Beset with such problems as remarkably low grinding efficiency, abnormal grindstone abrasion, and noise, this process has become a bottleneck in the automation of maintenance and repair. The present study addressed the grinding problems in welded hardfacing and attempted to optimize the grinding method through functionality evaluation, When the results of the study were applied to actual production equipment, they demonstrated consistently efficient grinding and held grindstone abrasion to one third of its former value. The findings of the study became guidelines for the automation of the complete sequence of processes from hardfacing welding to finish grinding in the on-site maintenance and repair of large plant equipment.
