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  • Author: Jarosław Brodny x
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Jarosław Brodny

Frictional joint is the basic part of the friction props and yielding steel frames of dog headings. It constitutes a constructional connection and have decisive influence on the basic operational parameters of the steel frames and props, i.e. their loading capacity and yielding capacity. Currently applied constructions of frictional joints characterize with low loading capacity and unstable operation. In order to improve their operational parameters a new constructional solution of frictional joint, consisting on the application of resistance wedge assembled between the cooperating sections, was developed. Application of the resistance wedge caused an increase of resistances to motion in the frictional joint, what influenced on the increase of its loading capacity and on the increase of values of axial forces in the bolts of stirrups. In the paper results of stand tests of frictional joints with the resistance wedge, subjected to the static axial compression and impact of freely falling mass, were presented. In order to determine the influence of the resistance wedge on the operational parameters of the frictional joint, obtained results were compared with the results of studies of the frictional joints without the resistance wedge. On the basis of stand tests a physical and mathematical models of the frictional joint with the resistance wedge, were developed, and utilized to simulation analysis of its operation at impulse loading. On the basis of conducted tests and analysis one can state, that application of the resistance wedge influences on the enhancement of loading capacity, improves the state of loading the bolts in stirrups, and creates possibility of regulation of operational characteristics of the frictional joints

Open access

Jarosław Brodny

Abstract

In the recent years, industrial automatics practically was used in all domains of economy. Particularly, it concerns to manufacturing processes and technological processes. It seems that in these systems, very important meaning have measuring and control devices, installed practically in all production machines. Operational parameters of machines, registered by these systems are the kind of source of very important information, which not always are utilized in proper way by the users. Particularly, it concerns mining branch, where more technically advanced machines are used. However, not always their users utilize the big potential of these machines. For this reason, in the paper there are presented results of studies, enabling the application of industrial automatic systems to analyze operation states of machines, based on registered parameters of these machines. Longwall shearer was submitted to detailed analysis as the most important machine in mining exploitation process. There are presented proposals for application registered data for determine effectiveness of its utilization and to diagnose its technical condition. Presented paper is aimed to realize and encouraging users to wider practical use of the capabilities of industrial automation systems. This should improve efficiency and safety of production processes.

Open access

Jarosław Brodny

Abstract

Unscheduled downtimes in machine operation are one of the main reasons behind their low availability. Such downtimes are caused by miscellaneous factors and remain difficult to identify in a number of cases. This particularly refers to enterprises that conduct their activities in changing external conditions, such as hard coal mines, where exploitation is carried out in extremely complicated, changeable and dangerous conditions. The process of coal production makes use of various machines that must be adapted to these conditions. The specificity of the working environment makes it necessary for these machines to exhibit high reliability, readiness and efficiency. These features, in turn, make the cost of the machines very high. It is therefore reasonable to make the best use of their capabilities, which translates into the effectiveness of the entire production process. The article concentrates on determining the availability of these machines. It has been assumed that availability is one of the fundamental parameters that define the effective utilisation of machines. The tests were conducted for a longwall shearer as well as an armoured face conveyor and a main haulage conveyor in one of the hard coal mines in Poland. Industrial automation systems were used to determine unscheduled downtimes in the operation of these machines, as well as their time structure and causes. The results obtained indicate that the number of unscheduled downtimes represents a serious problem in mining exploitation.

Open access

Jarosław Brodny

Abstract

Yielding support, commonly applied to secure dog headings, is made of carrying elements in the form of steel frames and friction props. Yielding capacity of this support is realized in frictional joints, which due to their geometry can be divided to straight and arch joints. Occurring in steel frames arch frictional joints are characterized with more complex loading state than straight joints used in friction props. In the article, there is presented an analysis of the state of stress and deformation of the arch frictional joint, which was carried out on the model of these joints using finite element method. The scope of the analysis included two methods of loading of arch frictional joint, namely its axial compression and bending. In both cases, joints were loaded dynamically with the impact of freely falling mass. Arch joints with and without passive pressure were submitted to an axial compression. Physical model of the frictional joint was developed on the basis of a system applied during the stand tests. To solve mathematical model an explicit integration method was used. As a result of analyses carried out, temporal courses of force transmitted through the frictional joint, and displacements of section sliding down were determined. On the basis of the temporal courses, dependences between maximum value of force transmitted through the frictional joint and the height from which the impact mass falls down were determined. Distributions of reduced stresses in elements of frictional joint were also determined and the state of deformation was described. In order to emphasize the difference between straight and arch frictional joints, also an analysis of internal forces in arch frictional joint depending on its geometrical parameters without and with passive pressure was presented.

Open access

Dawid Szurgacz and Jarosław Brodny

Abstract

The article presents the results of tests and analyses of control functions performed by a powered roof support which is the basic part of a powered longwall system. The research was based on an innovative registration and measurement system dedicated to this specific range of tests. The basic element of this system is a virtual driver. It is equipped with input and output systems to connect standard physical voltage signals. The tests were carried out on a prototype powered roof support type ZPR- 15/35-POz. The presented research methodology and obtained results are an element of new research methods developed for powered support based on virtual controllers. The applied solution generates less costs than the devices currently used, while its functionality is significantly greater. The system developed by the Authors supports innovative and, to a certain extent, intelligent IT solutions for testing control elements. This developed system is suitable to be applied in a wide range of research such as diagnosis of mining machinery control elements and other industries in the near future.

Open access

Dawid Szurgacz and Jarosław Brodny

Abstract

Mining machines suitable for hard coal mining, due to the specifics of this industry must be characterized by very high technical parameters. In particular, it concerns their durability, reliability and availability. Currently used machines approved for operation in underground conditions meet such requirements. Nevertheless, during their operation it is reasonable to conduct supervision and control of work parameters. This applies to both machine manufacturers and users, which is especially important in the event of a failure. Mine employees should be able control of the entire operation process. This control can be effective thanks to a visualization system developed to monitor the working parameters of mining systems. The paper discusses the innovative system and presents the results of efficiency tests. They concerned the visualization of the operation of a powered roof support. The obtained results indicate that the assumed goal of the system has been achieved. The system is built on elements of industrial automation, which guarantees the reliability of the indicated values. Its graphic layout and selection of the presented parameters are also approved. It should also be emphasized that the system can work with currently operating systems and is easy to expand. According to the Authors, the system should find a wide application in practice.

Open access

Anna Timofiejczuk, Jaroslaw Brodny and Andrzej Loska

Abstract

The article is a review of completed research on developed and implemented innovative and technologically advanced technical systems. According to the Industry 4.0 concept they can have a significant impact on the efficiency of production processes and product development. In this perspective, the key aspect seems to be maintenance management of technical systems, realized both in the operate phase as well as during service and repair works. There were discussed research results of authors and developed application solutions supporting decision-making processes, in terms of three main periods of realization of exploitation processes: short, medium and long-term.

Open access

Jarosław Brodny and Magdalena Tutak

Abstract

One of the most dangerous and most commonly present risks in hard coal mines is methane hazard. During exploitation by longwall system with caving, methane is emitted to mine heading from the mined coal and coal left in a pile. A large amount of methane also flows from neighboring seams through cracks and fissures formed in rock mass. In a case of accumulation of explosive methane concentration in goaf zone and with appropriate oxygen concentration and occurrence of initials (e.g. spark or endogenous fire), it may come to the explosion of this gas. In the paper there are presented results of numerical analysis of mixture of air and methane streams flow through the real heading system of a mine, characterized by high methane hazard. The aim of the studies was to analyze the ventilation system of considered heading system and determination of braking zones in goaf zone, in which dangerous and explosive concertation of methane can occur with sufficient oxygen concentration equal to at least 12%. Determination of position of these zones is necessary for the selection of appropriate parameters of the ventilation system to ensure safety of the crew. Analysis of the scale of methane hazard allows to select such a ventilation system of exploitation and neighboring headings that ensures chemical composition of mining atmosphere required by regulation, and required efficiency of methane drainage. The obtained results clearly show that numerical methods, combined with the results of tests in real conditions can be successfully used for the analysis of variants of processes related to ventilation of underground mining, and also in the analysis of emergency states.

Open access

Dorota Palka, Jarosław Brodny, Tamer Rızaoğlu, Utku Bağci and Jozef Maščeník

Abstract

The article presents the results of literature research in the field of Technology Assessment (TA). In particular, the attention was focused on searching for trends determining the directions of development of this research area. Research gaps constituting the basis for undertaking new cognitive challenges were identified. As a research method, a systematic review of literature was adopted, the methodology of which was described in the first part of the article. The analysis includes a total of 1788 TA-related scientific articles available in Google Scholar and BazTech databases. The practical part of the article presents fragments of literature research and an attempt to define the concepts of Technology Assessment on their basis. The collected research material showed a high degree of variation in the scope of definitions and the research area covered by TA. This indicates the need to conduct further research in this area for the purpose of clarifying the research area which TA deals with. It is legitimate to say that the development of research in this area is necessary due to the increasing impact of technology on society.

Open access

Andrzej Szajna, Janusz Szajna, Roman Stryjski, Josef Basl and Jarosław Brodny

Abstract

Augmented reality technology (AR), also known as mixed reality, allows to enhance the seen reality with additional, virtual objects, displayed right in front of the user’s eyes. The article presents the concept of using Augmented Reality glasses, to support the user with pre-defined knowledge and instructions, giving the ability to do the job without almost any idea of what should be done. The operator simply follows the instructions shown in front of the eyes and communicate with the system with simple gesture and voice. Additionally, the article touches the topic of Artificial Intelligence (AI) which will allow the system in the future to have not only the pre-defined, hard coded instructions, but also the flexibility to give different hints to the user based on a different situation observed.