Górnictwo i Geoinżynieria
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ISSN 1732-6702
Issue Date
2011
Volume
R. 35
Number
Nr 3/1
Description
Journal Volume
Górnictwo i Geoinżynieria
R. 35 (2011)
Projects
Pages
Articles
Corrosion behaviour of selected power plant materials under oxyfuel combustion conditions
(Wydawnictwa AGH, 2011) Abang, Roger; Findeisen, Alexander; Krautz, Hans Joachim
To reduce the production of anthropogenic $CO_{2}$ emissions, two lines of research are being investigated for fossil fuel-fired power plants, especially for those fired with lignite. One line concentrates on increasing efficiency in conventional power plant units (e.g. 700 degrees of Celsius technology, coal drying) while the other concentrates on the implementation of $CO_{2}$ - reducing technologies including pre-combustion, post-combustion and oxyfuel technology. The standard low Nox-producing operation of large and modern lignite-fired power plants as well as the altered process conditions that occur when oxyfuel technology is implemented results in combustion conditions that cause damage to system components. Therefore, the corrosion of plant components as a result of contact with flue gas plays a particularly significant role. Within the framework of a BMBF-funded project investigations focussing on the corrosion behaviour of selected plant materials under conventional air and oxyfuel combustion conditions are being evaluated. These investigations were carried out in a 500 kWth test facility over a timeframe of 110 hours and initial corrosion occured. The corroded probes are then placed for a further 1.000 hours in a laboratory test rig at the BTU Cottbus, Chair of Power Plant Technology. The material probes investigated were: 16Mo3, 13CrMo4-5, 7CrVTiB10-10, 10CrMo9-10 and VM12SHC. Subsequently, the probes are analysed with the help of light and scanning electron microscopes. From the results of the investigations, conclusions on the corrosion behaviour of materials and altered process conditions can be reached, which also demonstrates the need for further investigations to be carried out in this area.
Ocena zasobu trwałości zmęczeniowej ustrojów nośnych maszyn podstawowych górnictwa odkrywkowego
(Wydawnictwa AGH, 2011) Alenowicz, Jerzy; Onichimiuk, Marek; Wygoda, Marian
Specificity of operation and construction of opencast mining basic machines has been presented in the paper. Regulations of load carrying structures dimensioning and existing inconveniences have been discussed. Reasons of fatigue fracturing in these structures have been indicated. Previous assessment methods of fatigue life resources based on research have been presented. Description and operational scheme of a system of constant monitoring of load carrying structure effort of opencast mining basic machines has been placed. Advantages resulting from system implementation in current exploitation of machines have been given. Possibilities of system implementation in brown coal opencast mines have been discussed.
Strategia utrzymania w ruchu długotrwale eksploatowanych maszyn podstawowych górnictwa odkrywkowego
(Wydawnictwa AGH, 2011) Augustynowicz, Józef; Dudek, Dionizy; Dudek, Krzysztof; Figiel, Andrzej
Achieving an appropriate quality of open pit mines basic machines after modernizations requires diagnostic estimations of their current degree of degradation and developing a detailed analitycal and technological methodics for moderization. It is also necessary to develop and carry out scientifically proved methodics and technology of creation, diagnosis and control of machines after modernization.
Potrzeba opracowania własnych urządzeń diagnostycznych do automatycznej oceny stanu taśm przenośnikowych w kopalniach odkrywkowych
(Wydawnictwa AGH, 2011) Błażej, Ryszard; Jurdziak, Leszek; Zimroz, Radosław
Review of available on the market conveyor belt inspection tools for assessment of their condition has shown lack of openness of ready solutions on cooperation with existing in mines belt databases and lack of possibility to create own applications based on source diagnostic signals with usage of additional information from these databases. This situation induce authors to create the machine vision device for belt cover inspection and process source signal from magnetic scanner of belt cord. The aim is to work out comprehensive set of devices and algorithm processing collected data and making integrating evaluations of belts condition in order to aid taking rational decisions about their replacements taking into consideration possibility of effective and economically profitable belt refurbishment. System will be not only used for assessment of belt and its core condition, but also will protect belt and conveyor before catastrophic event such us longitudinal rips. It will also create schedules of essential repair works. Due to close cooperation with future users the worked out system should very well fulfill their needs. They can be taken into account at the design stage and during defining its functionality. Authors of solutions have decided to put more attention on possibility of automation of carried out assessments and their recording in databases in order to minimize necessity of human interpretation and intervention everywhere it will be possible. Quality financial analysis has shown that it is possible to lower total transportation cost increasing expenditure on automatic diagnostics of conveyor belts.
Analiza wytrzymałościowa koła czerpakowego koparki w warunkach założonej wydajności
(Wydawnictwa AGH, 2011) Czmochowski, Jerzy; Kaczyński, Paweł; Moczko, Przemysław
Assembly, which is particularly strained and vulnerable to failures is the mining system of multibucket excavators, especially the buckets and the bucket wheel. The paper presents a strength analysis of bucket wheel at the assumed, required performance. The analysis was conducted for the various categories of land, for a specified number of buckets, velocities and power of transmission system. This issue is particularly important at changing the mining conditions and possibilities of increasing efficiency while maintaining the required stability. An analysis of the forces encountered during excavation was conducted. The total resistance of the mining, cutting resistance torque and power at the assumed resistance of the mining efficiency were determined. These data are included in the carried out strength calculations according to PN-G-47000-2 standard, which allowed to assess the applicability of the assumed productivity.