The process of designing a longwall powered support is extremely complex and requires many operations related to the creation of a complete machine. The powered support section is one of the basic elements of the longwall system. It acts as protection for the working space and takes part in the process of excavating and transporting the spoil. The implementation of the support that meets the guidelines of the manufacturer and user requires an endurance analysis at the design stage conducted according to the regulations in force. The main objective of this research, pursued by the authors, was to perform the analysis of the ultimate strength of selected elements of the designed powered support section. The research was carried out with the use of special software that uses the finite element method. This article presents the analysis of the strength limits conducted with the help of the finite element method, determining the strength of selected elements of the longwall support section. The solutions proposed by the authors include changes in the structure and properties of the material in the design process. The aim of the proposed solution was to obtain a model with strength value that meets safety standards. The research results are a valuable source of knowledge for designers. Solutions of this type set examples for spatial models of the longwall support section being designed currently. The analysis presented in the article, together with the results of the research and the conclusions resulting from them, may improve the safety and effectiveness of powered supports.
9 November 2024 in Management Systems in Production Engineering
Currently used machine diagnostic systems are based on very modern solutions based on the acquisition and recording of their operating parameters in real time. Increasingly available and high-tech sensor systems mean that the number of recorded parameters is increasing and their quality is improving. These data are mainly used to assess the technical condition of machines and the processes they perform. In mining, these data can also be used to assess and, at a later stage, improve the safety of the underground mining process. Referring to this issue, the paper presents examples of the use of diagnostic systems for powered roof supports and longwall shearers to assess the safety status of the underground hard coal mining process. In the case of the wall support, the focus was on measuring the pressures in the stands of its individual sections. Temporary changes in the values of these pressures constitute a valuable source of information regarding the interaction of the support with the rock mass. In particular, this concerns the identification of the effects of the informational impact of the rock mass on the longwall excavation protected by the support. The research results presented in the paper, especially in the case of very dangerous dynamic impacts, indicate the possibility of both diagnosing the operating condition of the section and identifying symptoms of exposure to such events. This undoubtedly significantly expands the possibilities of using the measured pressures. Diagnostic signals from a longwall shearer are also widely used. The current intensities drawn by its motors while cutting the rock mass, as well as the advance speed and its position in the wall make it possible to analyze these parameters and their changes before, during and after the occurrence of various types of events. These data enable the assessment of the effects of the rock mass on its operational efficiency and safety status. It also enables the identification of symptoms that precede the occurrence of such events. The presented examples indicate the need for a broader and more holistic approach to the use of diagnostic parameters of mining machines. In particular, this concerns the study of the cooperation between the support and the rock mass and its influence on the efficiency and safety of the rock mass mining process. The subject matter addressed relates to very important and current issues, and the developed methodology and obtained results should be applied in practice as soon as possible.
The main objective of this study was to develop a comprehensive testing method for powered roof supports operating under real mining conditions and to establish guidelines for a monitoring system designed to record their geometric and operational parameters. The proposed methodology included analyses of load-bearing capacity limits, laboratory model tests, bench tests, and in situ investigations under actual working conditions. Based on these studies, a detailed testing procedure was developed, defining the sequence of experimental stages, the selection and calibration of sensors, their installation and servicing methods, as well as the integration of measuring equipment with the support structure. The key results demonstrate that the proposed method allows for reliable acquisition and interpretation of data concerning the operational behavior of powered roof supports. The findings enabled the identification of critical geometric and operational parameters influencing the stability, durability, and efficiency of the support system. The developed monitoring procedure, supported by both laboratory and field tests, provides a consistent and replicable framework for assessing the performance of roof supports in real-time mining operations. The conclusions confirm that the presented approach represents an innovative and systematic method for evaluating and monitoring powered roof supports under real conditions. The main contribution of this work lies in the formulation of universal guidelines for the design and implementation of monitoring systems, significantly improving the safety, reliability, and efficiency of mining processes.
1 September 2024 in Civil and Environmental Engineering Reports
Monitoring of operating parameters of machines and devices is recently used more often in hard coal mining. This solution is one of the elements of the intelligent mine concept. This concept means that the enterprise uses innovative technologies while considering economic and social factors. The aim of applying practical solutions under the guiding idea is to increase the efficiency of the production line and the safety of the crew's work. The authors propose introducing a system monitoring the geometrical parameters of the powered roof support. The proposed system fits the requirements of creating an intelligent mine, a plant that meets the global safety and efficiency requirements. The article depicts studies of the underground working conditions of the section geometry monitoring system. The tests contributed to determining sensor installation locations and clarifying the geometric parameters of the measurement and recording system. The system is a solution so far not used in Polish hard coal mining at such a highly advanced level. Based on the measurements, the tested system determined the transverse and longitudinal inclinations of the essential elements of the section. In addition, through the designated angles, the working height of the section in the wall excavation was determined.
In the Polish mining industry the currently used monitoring systems for production processes and safety have been analyzed. The main aim of the analysis was to demonstrate the usefulness of the monitoring systems which are being used. The scope of the analysis in question also took into account the economic aspects together with natural hazards or failures of machines and devices. The performed analysis allowed to determine the usefulness of the monitoring systems used in the Polish mining industry. This article presents a questionnaire study that determined the area of application, the level of use and the suitability of monitoring systems in the mining environment. Well-selected systems for monitoring the production process are necessary to ensure safety and comfort of work. On the basis of the conducted analyzes the operation of monitoring systems was illustrated in relation to the development of modern technologies.