Optimization of conveyor roller, LKAB

Abstract

ABSTRACT The aim of this thesis is to optimize the performance, material, life and accessories for the conveyor rollers installed in longest conveyor section “15101 smst TR010” of LKAB Narvik, which is under the SILO with overall conveyor length of 620 meter. The report outlines the problems created by groundwater falling inside the tunnel, dust and spoilage of iron ore pallets outside the conveyor belt to create a major problem for the carrying side idlers. LKAB, produces iron ore and in Narvik, a big facility is installed in which, heavy duty steel conveyor rollers are used to move the iron pallet by receiving from train to moving towards the shiploader area inside the plant. The major problem for roller stucking due to above mentioned environmental conditions has been studied and a new concept of idlers are recommended considering all the problems, requirements and constraints. One of the satisfactory result is 13.3 % overall weight reduction in whole conveyor unit. In troughing idler set, two different sized rollers are used namely central roller and side roller, where, central roller is horizontal and side rollers are troughed by 45°. Central roller has designed with 20.38% weight reduction in rotating parts( cylinder, bearings, bearing hub and seals), where as 11.6% total weight is reduced in one single roller. In case of side roller, 26.34% of weight is reduced in rotating parts, likewise, 15.5% total weight is reduced in a single roller. The conveyor rollers are equipped with high performance bearings, but in existing case, bearings are stucking frequently due to dust and water issue, so that bearings with more feature are used in a new design to reduce the repair and maintenance cost. One positive result of weight optimzation is that 6944 watt electricity has been saved. Likewise, the bearing life has been increased to 50900 hour from 15000 hour after selection same sized but extra featured bearings. Overall, the new concept of rollers-LKAB are generated as a optimization in weight, performance, and life consideration in co-operation with LKAB Narvik and the department of Engineering Design UiT Narvik Campus.