Magdalena Tutak

Use of Intelligent Informatics Module for Registration and Assessment of Causes of Breaks in Selected Mining Machines

Growing competition and an unstable energy market force mining enterprises to take actions aimed at decreasing production costs. The area in which there are great reserves linked with costs is a use of mining machines that are owned by mining companies. In practice, it has been observed that underutilization of mining machines at present is one of the main problems in mines. The paper presents the results of research whose aim was to determine availability and performance of the studied machines and quality of the excavated material which was the product of the machines’ work. Based on the results, the effectiveness of the machines was determined. In the area of availability a large number of the unidentified breaks during the machines’ work was registered. To find the causes of the breaks, many interviews with expert workers from maintenance departments were made. Using their knowledge, the special and intelligent module for the reasons for the breaks registration were developed and implemented. This module has been permanently linked with the integrated management and maintenance system that had been used in the mine. The application of the developed solution made it possible to indentify more than 72% of the breaks in the studied machines’ work and it was an increase by 90% in relation to the level before its installation. It appeared that the main cause of the low efficiency of the reasons identification was the lack of dispatchers’ knowledge and motivation. The obtained results make it possible to take activities in order to reduce the breaks in the studied machines’ work and subsequently improve their effectiveness.

The Use of the TGŚP Module as a Database to Identify Breaks in the Work of Mining Machinery

The article presents the results of the causes of breaks in selected mining machines work. The studied machines belong to the mechanized longwall system. Identification of the causes of these breaks was carried out using author’s database that was created on the basis of the information coming from the application, which is an integral part of the Means of Production Management Module (TGŚP). This module is one of the basic parts of the integrated enterprise management system SZYK2. The results clearly show that the developed solution enables more efficiently to identify the causes of breaks in examined machines work than previously used systems. It is the result of acquiring the tacit knowledge from dispatchers thanks to developed solutions.

Analysis of Methane Hazard Conditions in Mine Headings

One of the most dangerous and the most common hazards in coal mines is methane hazard. This threat is associated with inflammation and/or explosion of methane in the mixture of air. Analysis of the scale of methane hazard allows the selection of such a longwall ventilation system operating, which provides the requisite provisions of the chemical composition of the mine atmosphere, and the required efficiency of methane drainage. The article presents the results of numerical analysis of the flow of the mixture stream of air and methane by the layout of workings of one of the mines. The aim of this study was to analyse the workings and the designation of zones of the ventilation system in question, where there may be dangerous, explosive concentrations of methane. The results are important when taking preventive actions aimed at reducing methane emissions to the external environment in the process of methane drainage.

A Data Warehouse as an Indispensable Tool to Determine the Effectiveness of the Use of the Longwall Shearer

The effective use of machines and devices in the mining industry is significant. In a competitive energy market, such effectiveness can decide about the further functioning of the company in many cases. The article subject refers to these issues, in particular, to the way of determining the availability of a longwall shearer used in underground coal mining. The article presents the proposal of using the data warehouse to determine the level of load of a longwall shearer during its work on the basis of shearer motor power consumption time series.

Exposure to Harmful Dusts on Fully Powered Longwall Coal Mines in Poland

The mining production process is exposed to a series of different hazards. One of them is the accumulation of dust which can pose a serious threat to the life and health of mine workers. The analysis of dust hazard in hard coal mining should include two aspects. One is the risk of coal dust explosions, which poses a direct risk of injury or even loss of life, the second is the risk of harmful dust, associated with the possibility of negative health effects as a result of long-term exposure to dust in the worker’s body. The technologies currently applied in underground mining produce large amounts of coal and stone dust. Long-term exposure to dust and crystalline silica may cause chronic respiratory disease. The article presents the results of tests on the dust levels in the area of a fully-powered longwall. The tests were conducted for five longwalls from different hard coal mines. In each of them, the average values of inhalable and respirable dust as well as the percentage content of free silica in the dust were determined in ten selected working positions. Additionally, for the longwall with the highest dust concentration, the levels of dust were determined for the basic activities related to the phases of the technological cycle. The comparative analysis conducted and the results obtained demonstrate large variations in the dust levels in the different areas. The permissible values were significantly exceeded in a number of cases. This poses a great threat to the health of Polish miners. The results obtained indicate that it is necessary to undertake more effective measures in order to improve the working environment of the crew in hard coal mines.

Analysis of Availability of Longwall-Shearer Based On Its Working Cycle

Effective use of any type of devices, particularly machines has very significant meaning for mining enterprises. High costs of their purchase and tenancy cause that these enterprises tend to the best use of own technical potential. However, characteristics of mining production causes that this process not always proceeds without interferences. Practical experiences show that determination of objective measure of utilization of machine in mining company is not simple. In the paper methodology allowing to solve this problem is presented. Longwall-shearer, as the most important machine between longwall mechanical complex. Also it was assumed that the most significant meaning for determination of effectiveness of longwall-shearer has its availability, i.e. its effective time of work related to standard time. Such an approach is conforming to OEE model. However, specification of mining branch causes that determined availability do not give actual state of longwall-shearers operation. Therefore, this availability was related to the operation cycle of longwall-shearer. In presented example a longwall-shearer works in unidirectional cycle of mining. It causes that in one direction longwall-shearer mines, moving with operating velocity, and in other direction it does not mine and moves with manoeuvre velocity. Such defined working cycle became a base for determinate availability of longwall-shearer. Using indications of industrial automatic system for each of working shift there were determined number of cycles of longwall-shearer and availability of each one. Accepted of such way of determination of availability of longwall-shearer enabled to perform accurate analysis of losses of its availability. These losses result from non-planned shutdowns of longwall-shearer. Thanks to performed analysis based on the operating cycle of longwall-shearer time of its standstill for particular phase of cycle were determined. Presented methodology of determination of longwall-shearers availability enables to obtain information which may be used for optimization of mining process. Knowledge of particular phases of longwall-shearers operation, in which reduced availability occurs, allows to direct the repairing actions exactly to these regions. Developed methodology and obtained results create great opportunities for practical application and improvement of effectiveness of underground exploitation.

Numerical Analysis of Airflow and Methane Emitted from the Mine Face in a Blind Dog Heading

Ventilation is one of the most common presented problems during the driving of dog headings. During driving such heading has only one connection with air stream routes, which significantly make difficult the process of its ventilation. In a case of its driving in coal in the methane seam, this heading is endangered also to methane emission. In such case process of its ventilation is much more difficult. In the paper there are presented results of numerical analysis of ventilation of blind dog headings using air-duct forcing the air into its mine face. The analysis was performed for four different velocities of the air at the outlet from air-duct. The calculations were made for the excavation of heading with heading machine and conveyor belt. NUMERICAL ANALYSIS OF AIRFLOW AND METHANE EMITTED FROM THE MINE FACE IN A BLIND DOG HEADING