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ABSTRACT
Calculation of motion resistance of belt conveyor shown underestimation in comparison to results of conducted measurements. The main component of motion resistance for conveyors longer than 80 m are primary resistance. Furthermore, indentation rolling resistance can generate more ten half of them. Disproportion between measured and calculated values can be determined by the component which is predominated. This indicated the need to verify theoretical method of determining rolling resistance. To improve calculations new approach for damping properties is also necessary. Damping factor is the most important parameter in calculation of rolling resistance and can be determined on the basis of laboratory hysteresis loop for cyclical transverse compression. Getting hysteresis loop adequate for cyclic process of belt indentation is unreachable in laboratory conditions. Therefore hysteresis loop for continuous harmonic load is used. This paper shows how to convert damping factor from cyclic harmonic load to damping factor adequate for rolling resistance of belt.
Keywords: indentation rolling resistance, damping factor, conveyor belt
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INTRODUCTION
Belt conveyors are an indispensable means of transport in a number of industries. They are typically installed in factories, warehouses or at airports, but most extensively used in both underground and surface mining. State of the art conveyors are capable of transporting materials over large distances, as well as slopes and uneven terrain surfaces. In doing so, they prove highly efficient and reliable. Despite their numerous advantages, operation of belt conveyors remains expensive. The high costs are mostly due to the consumption of electric energy, which may account for as much as 50% of the total electricity demand in a mining plant [1]. For this reason, works on improving belt conveyor transportation systems have mainly focused on reducing their energyconsumption [2, 3, 4, 5, 6].
Belt rolling resistance is the greatest component of main resistances in belt conveyors. In the case of conveyors longer than 80 m, where primary resistances are the dominant component of motion resistances, belt rolling resistance may be the decisive factor in the energy consumption of conveyor belts. According to test results, motion resistances are frequently underestimated in theory [7, 8]. Literature mentions a number of methods for determining both the resistances to motion of a complete idler set and indentation rolling resistances...