166 / 2021-10-29 14:04:05

Powered roof support operating in changing mining and geological conditions

geology,hard coal

The extraction of hard coal, an energy source and raw material, is highly valued in the global economy, therefore, various types of research and scientific work focused on coal is reasonable. Such activities are improving the operation of the mining longwall system performing the manufacturing process. Currently used machinery and equipment require modernization and implementation of new solutions that increase the safety and efficiency of work, and thus improve the economic conditions of coal companies. The increasing operational depth forces the introduction of innovative and intelligent solutions. The implementation of this imperative perfectly suits the research areas that this paper deals with, covering the issues related to the operation and use of the powered roof support used in longwall complexes.

The paper focuses on the analysis of the work of the most important elements of the powered roof support, such as hydraulic legs. The superior character of the legs results from the fact that the parameters of their operation have a decisive influence on the operation of the powered roof support and thus on the operation of the entire longwall system.

The basic cognitive goal of this paper was to identify the work parameters taking into account the pressure values as a result of the dynamic load for the space under the piston of the leg and the safety system. To meet the growing demands on the roof support performance parameters, the Author focused on the development of a measuring system that determines the operating parameters of the leg’s control system, and a measuring system that determines the actual geometry of the section.

The necessity to achieve the set goals and the multi-aspect nature of the subject has forced a wide scope of the study, including theoretical considerations and experimental research. The theoretical considerations covered the scope of the analysis of the work of the powered roof support and its selection to the mining and geological conditions of the analysed longwalls in which the support worked. The research included tests on hydraulic legs carried out in a testing station. The analysis of operation of the roof support was focused on developed theoretical model defining the geometric parameters of the sections. The model was then used to conduct simulation calculations. The theoretical identification of geometrical parameters of the support sections was obtained.

The reserach covered the dynamic test of the leg together with the safety system. The results of these tests form the basis for the experimental identification of the work parameters of the leg and were used for the adopted assessment of the yielding based on the predicted and actual energy of a tremor.