Drivning av bandtransportörer : Ett förarbete till en standardisering

LKAB has a large number of belt conveyors which function is to transport material in the refining process of iron ore. The drive of the belt conveyors is in general operated by an electric motor, which trough a gearbox makes a drive drum to rotate. The gearbox can be found in several brands, available in various size and designs. The numbers of variants have increased over time and LKAB wants to reverse this trend. The costs of inventories have been increasing and the production can be negatively affekted if right gear box cant be found at the storehouse, or if the mechanist who is working with the gearbox is unfamiliar to the specific type of gearbox. Therefore it can be worrying with too many different types of drives in case of breakdown. This work can be seen as a preparatory work for a standardization, in which three different producers are compared to find the best choice of drive of the belt conveyors. To get an idea of the situation at LKAB the author began the process of making an inventory of existing belt conveyors. A data store and a business system at LKAB's internal network were used in the work. The inventory revealed that three manufacturers were represented at considerable extent, therefore it was decided that these three were to be further analyzed. The manufacturers are Benzlers, Kumera and Rulmeca. Benzlers and Kumera have broad exchange programs from small handy gears to large heavy industrial gears. But most common at LKAB is Benzlers J-series also known as SALAgear, and Kumera RFM series. The main difference is that the SALA-gear is driven by belt drive and in a Kumera gearbox the engine is directly connected to the gearbox. Rulmeca has a different build-up, the entire drive package is included in the so called drive pulley, these are called motorized pulleys. To compare the three selected manufacturers each gearbox or motorized pulley was analyzed. The manufacturers were also reviewed to see what distinguishes them and how they relate in comparison with each other. Since power consumption is important measurements of power consumption during operation were made both in Svappavaara and in Kiruna. These measurements then was compared with the mass of iron ore that passed the conveyor, this to obtain a fair picture of energy consumption. The result indicated that Rulmeca, who markets itself as energy efficient actually was the cheapest alternative in energy. Economic comparisons were performed to get an idea of how the three brands relate to each other in cost terms. Investment costs and the total costs incurred during the gears lifetime was made, with help of LCC (Life Cycle Cost). Finally, to find the best drive alternative for a belt conveyor a Pugh matrix was established. Important criteria for a supplier of drive units were treated in the Pugh matrix. The criterias were reviewed to determine their importance in relation to each other (weight value). Then, all three manufacturers got their own scores for each criterion and final scores could then be determinedValiderat; 20110105 (anonymous