Trends in the growth of aggregated measures of failures in a steel conveyor belts core

Abstract

Abstract The initial set of four measurements captures the failures occurring in the core of steel link conveyor belt segments used in a lignite coal mine in Poland. These measurements utilize the DiagBelt+ magnetic system, enabling the analysis of averaged damage sizes. Specifically, the sizes of digital damage signals in a 2D image of the belt are examined, with "x" representing the size along the belt axis and "y" representing the size across the belt (measured in the number of channels detecting damage times 25 mm). The loop of the 2021-meter-long conveyor belt consisted of 11 segments of different ages. Measurements were conducted four times over a span of less than 2 years, allowing for the observation of averaged size changes for a maximum of 6 different time intervals ranging from 1 to 19 months (approximately 1, 6, 7, 12, 13, and 19 months). Due to the replacement of several segments during the analyzed period, five segments were examined only three times. Conducting measurements on the same conveyor allowed for the examination of changes in the number and sizes of failures while maintaining the stability of all factors that could influence the rate of damage development. The type of material being conveyed (overburden), belt speed (6 m/s), and conveyor length (approximately 1 km) remained constant. The primary factor causing changes in the number and sizes of damages was, therefore, the duration of belt operation between measurements. The aim of the research was to determine the nature of cumulative increases in length and width of failures in segments over time between measurements. It was found that these increases could be described by linear functions, but their growth rates (expressed by the slope coefficients of the lines) depended on the age of the belt at the time of the first measurement. A regression function was determined for the slope coefficients Ax and Ay in relation to the belt's age. The obtained results are of significant importance for the possibility of developing a reliable short-term forecast of the rate of damage changes in the following months based on the latest measurement. This allows for rational management of the belts, including planned replacement of segments based on their condition, preparation of a belt demand schedule, and aligning the budget with replacement needs.