D. Sládková
The Utilisation of GNSS technology for mining process automation
Abstract: VŠB-Technical University of Ostrava, institute of geodesy and mine surveying has been cooperating with Severočeské doly j.s.c. (SD) in important research project since 2007. The main goal is improve control system for opencast mining. Two bucket wheel excavators (K800/103 and KU300/27) were equipped with measurement hardware at the Libouš Lignite Mine (North Bohemia brown coal basin). The position of the bucket wheel centre is computed by means of GPS data, inclinometer and incremental measurements. Data is transferred to a base. All the values measured are saved in this database. The surface layout of the mine as well as positions of underground geological layers are updated on a regular basis in the digital model of the mine. The main aim of the research is verifying the system in connection to digital model for short time prognosis of qualitative parameters of coal (Ad, Sd, Qr, Wr and MS), continuous automatic computation of mined materials (m3, tons) and continuous checking of creation of the movement surface/plane of the excavator and mining goals. Mine surveyors have a lead role in the working team. The paper describes possibilities of using the GPS for mine surveying and for production planning.
Key words: analysis, bucket wheel excavator, digital model, GPS, inclinometer, incremental measurements
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R. Hamříková, J. Jurman
Effective energy utilisation with the excavator wheel
Abstract: The optimum utilisation of energy supplied to the excavator wheel rests upon the optimisation of mode parameters of breaking aimed at diminishing the energy demand of the mining process at keeping theoretical efficiency. With bucket wheel excavators, the mining process is subject, similarly to any process in the course of which rock breaking takes place, to general regularities influencing the final effect. Then, theoretical conclusions and practical results can be applied that have been verified in the operation of drilling units and tunnelling machines, in the course of which a considerable energy and thus also economic saving was made by the regulation of mode parameters of breaking. The solution proposed is based on the determination of basic dimensions of the cut mined, especially the width-depth ratio according to the criterion of minimum specific energy by volume.
Key words: energy efficiency, bucket wheel excavator, optimization
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V. Moni, F. Helebrant
Temperature picture of a bucket tooth and its’ service life
Abstract: The shape and the geometry of a bucket edge, its material and the material of a mechanical tooth are the key influences on the efficiency and energetic demands of mining processes with bucket wheel excavators. If the excavator units are often changed due to wear or breaking down, it increases the cost of the mining process, of course. It also reduces the service life of the machine and therefore it reduces the efficiency of the whole technological unit [TU] as well. Consequently, all wear causes not only changes to the shape and geometry or material features of the digging unit, but it also increases energy demands of the mining process, as mentioned. The presumption is – increased wear of digging units raises cutting resistances and consequently the temperature goes up due to higher friction and wear. Therefore, the picture of the temperature is the scale for measuring wear.
Key words: thermography, service life, bucket wheel excavator
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J. Garnczarek
The influence of teachers’ promotion on the quality of teaching – case study
Abstract: The article presents the problem of teachers’ professional promotion and its influence on the quality of teaching in one of the Silesian secondary schools. Therefore a survey was made among the teachers’ working in one of the secondary schools in the district of Silesia. The results of the research make us think about this problem, incline to reflection and deeper analysis. All the results are being and will be verified.
Key words: quality, education, survey, teachers’ professional promotion
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W. Biały
The selection of optimal method determining mechanical properties of coal layers
Abstract: The article presents selected methods and ways of mining resistance as well as mineability index determination with the use of different instruments. The principles of their operation and the way of mining resistance measurement as well as their usefulness in planning of cutting mining machines selection (longwall tumble heading machines) in given mining-geological conditions are discussed. Their advantages and disadvantages are presented and a method presenting actual mode of longwall tumble heading machines’ action is proposed. The results obtained with the use of this method should be taken as representative in the selection of cutting mining machines.
Key words: coal properties, analysis, the optimal method
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