State analysis of the vital steel structure of the bucket-wheel reclaimer operators cabin after the breakdown and the rehabilitation

Abstract

There are 2 bucket -wheel reclaimers, internally labelled as DU1 and DU2, made by French manufacturer 'Ameco', that operate at the open pit surface mine which belongs to the thermal power plant 'Nikola Tesla A' in Obrenovac. They are moving along the polar path and it should be noted that there are only 3 reclaimers of that kind in Eastern Europe. The third bucketwheel reclaimer, made by the same manufacturer, operates at the open pit surface mine that belongs to the thermal power plant 'Nikola Tesla B' in Obrenovac. In this paper the state analysis of the vital steel structure of the bucket-wheel reclaimer DU2 operators' cabin, made of pipes of various diameters and thicknesses, after the breakdown caused by a rock that hit the horizontal support of the structure is presented. The rock was located in the excavated coal within a bucket of the bucket-wheel reclaimer. The horizontal support of the operators' cabin structure has Bent and welded joints between flanges at the middle of the horizontal support, as well as welded joints at bonds of the horizontal support with vertical supports of the structure, have cracked due to the impact of the rock. Taking into account the fact that the user of the bucket-wheel reclaimer does not own the design and technical documentation, damage repair was carried out under the assumption that the lattice structure of the operators' cabin was made of structural steels, which are mostly being used for the manufacture of bucket-wheel reclaimers. On the basis of state analysis after the temporary repair of damages the conclusion arose that for the permanent provision of integrity of the support steel structure of the bucket-wheel reclaimer DU-2 operators' cabin as a whole it is necessary to replace the damaged horizontal support.