Crack repair on the bearing ring of the rotary kiln of the Kakanj cement plant

Abstract

This paper presents the issue of ensuring the integrity of structure i rotary kiln, after a catastrophic failure of integrity due to fatigue fracture of the bearing ring. Due to the impossibility of continuing production and the time required to replace the bearing ring with a new one, the only possible solution was repair welding. A total of 26 days (24/7) were worked nonstop in all weather conditions from + 25 ° C to 15 ° C, sun, rain, snow, ice and wind. It took over 550kg filler material (electrodes and wires) to repair the crack in the bearing ring in dimensions of Ø5400x900x370 made of casted steel 100CrMn6 over 40 years old. Special attention was paid to heat input, preheating temperature, interlayer temperature to prevent additional deformations and avoid remaining stresses after welding. After a month of intensive work, the rotary kiln was put back into operation condition, so that the Cement Factory d.d. Kakanj can again respond to the market requests for clinker and cement for the upcoming construction season.