Modeling and Simulation of the Methane Risk in the Mining Production Process

The mining production process is of particular importance for the area of Upper Silesia, as well as a very significant impact on the economy of the entire country. One of the most common and most dangerous threats to this process is the methane hazard. It is related to the presence of methane in coal seams, which under appropriate conditions is a flammable and explosive gas. Events related to the methane hazard constitute a huge threat to the life and health of the crew as well as the infrastructure and equipment of excavations. Therefore, they have a huge impact on the efficiency of the entire mining production process. In order to ensure the safety and continuity of the production process, it is necessary to prevent the formation of dangerous methane concentrations in the area covered by the operation. One of the tools that can be used to assess the state of methane hazard are model studies supported by numerical simulation. Based on these studies, the article analyzes the distribution of methane concentration in the mining area. This area included an actual mining excavation in one of the hard coal mines. The model tests were carried out with the use of the finite volume method in the ANSYS Fluent software. The obtained results can be used for preventive measures and constitute an important source of information for the assessment of the methane hazard state

Use of Reverse Engineering and Additive Printing in the Reconstruction of Gears

Despite the very rapid technological development, the general concept of mechanical devices has not changed. Still, the most common element of these devices are gears, whose range of use is very wide. There are both technological and historical considerations for the reconstruction of gears and other elements. In particular, this applies to spare parts for technical facilities that are not available on the market or service costs are too high. Contemporary reconstruction is called Reverse Engineering, which offers tools that allow transformation of an existing object through a virtual model into the final real product. Modern production engineering is based on innovative CAD – Computer Aided Designed design methods and computer-aided manufacturing technologies, CAM – Computer Aided Manufacturing. The rapid development of 3D CAD systems has led to the development of solutions to obtain the designed object, already at the development stage. Such a solution is the Rapid Prototyping method, designed for fast, precise and repeatable production of machine components. Widespread use and growing interest in the use of additive printing influenced the development of this technology. The purpose of the article is to present the practical application of the Reverse Engineering method and 3D printing in the reconstruction of gears. The object of research is the real gear, which has been reconstructed using Reverse Engineering and 3D printing. The article presents the basic assumptions of the methods used and the methodology for conducting reconstruction work. FDM (Fused Deposition Modeling) technology was used for the research. The results obtained are a real example of the practical application of the presented methods. At the same time, they create great opportunities for their wider use

Influence of the Permeability of the Longwall Goaf Zones on the Location of an Area With Explosive Methane Concentration Levels

One of the basic ventilation hazards and, at the same time most dangerous, in hard coal mines is the methane hazard. During the exploitation process using the longwall system with the breaking down of roof rocks, methane is released into mining excavations from both mined coal and the one left in goaves. Significant amounts of methane also flow from the underworked and overworked seams, through cracks and fissures formed in the rock mass. When accumulated at an explosive concentration level in goves and at an appropriate oxygen concentration level and the occurrence of a trigger (e.g. a spark or endogenous fire), methane may either explode or ignite. These are immensely dangerous phenomena. Therefore, the possibility of their occurrence should be limited. The article presents the results of the research aimed at determining the impact of the permeability of goaf zones on the distribution of methane and oxygen concentration levels in these goaves. The study was carried out for the longwall ventilated with the Y system. The model analysis was conducted, the results of which allowed the authors to determine these distributions. On their basis, both the location and size of the areas in which hazardous methane concentrations could occur were designated. The results are of great practical importance as they indicate areas in goaves where preventive measures should be implemented

Prospects for development movement in the industry concept 4.0

The aim of the article is to present the perspective of maintenance development in the context of the 4.0 industry concept. One of the factors that determine the safe and effective use of machines and devices is the properly maintained maintenance process. Correct performance of activities as part of this process requires the use of appropriate knowledge and experience from people implementing this process. Very important in this process is, above all, good organization of work and technical knowledge. The very rapid development of technology causes that teams dealing with the maintenance of traffic in enterprises must systematically acquire knowledge and optimize their activities. Effective exploitation of all types of devices is a set of rules, rules, procedures and actions, the main aspect of which is a human being. Knowledge resources should have appropriate substantive content adapted to the recipient. The article presents a modern solution supporting the maintenance process, taking into account the tools supporting the activities of human teams. The basic principles of maintenance in the enterprise covering machine monitoring systems, production management and management of information on the state of the machine park are discussed. There are also examples of the use of selected tools in the mining industry. Reference was also made to the prospects and directions of the development of maintenance in relation to the fourth industrial revolution

The concept of hard coal mine in the perspective of Industry 4.0

For the Polish economy, hard coal is the basic raw material for the production of electricity and heat, guaranteeing energy security. To ensure safe and effective work in underground mines, the most modern technical solutions are implemented. Innovative achievements of production automation are increasingly being used. Introduction of the Industry 4.0 concept elements is an opportunity for: improvement of coal exploitation processes, use of IT tools supporting decision-making processes and ensuring real-time process management. However, the specificity of the mining environment poses many barriers, for example limitations resulting from geology, extent and volume of excavations, device mobility and telecommunications. The article describes mining threats and limitations as well as the current technical condition of Polish mining. The latest trends in mining development are described in line with the ideas of the fourth industrial revolution. The main goal of the article is to analyze the feasibility of implementing Industry 4.0 concept solutions for underground mining. The analysis was performed with a tabular descriptive method, based on the conducted mining documentation, own observations, surveys and literature research. The indicated limitations and recommendations developed can serve as a guide to further scientific research and implementations in this area

3D Object Digitization Devices in Manufacturing Engineering Applications and Services

The rapid development of CAD 3D systems has led to the development of solutions enabling the physical achievement of the designed object, already at the design stage. Such a solution is the rapid prototyping method, intended for fast, precise and repeatable production thanks to additive technology. The first basic step of this method is a 3D scan. It is a technique that analyzes a real object in order to collect data about its basic (geometric) and additional (e.g. color) features. The collected data is used to generate three-dimensional, virtual models. Scanning can be performed in various ways using different devices. The aim of the article is to review the available technologies for digitizing 3D objects and to compare them in the context of individual application areas. It presents selected tools and software that will economically and efficiently increase the range of applications of digitization methods in the production process and offering various services on the market

Analysis of Stoppages in the Process of Roadway Drivage Caused by Exceeding the Maximum Allowable Level of Methane Concentration

Methane is one of the most dangerous gases occurring in mining production. Being inseparably connected with the rock mass, it presents a serious risk to occupational safety and reduces the effectiveness of mining production. A particularly high methane hazard occurs directly during exploitation in longwall headings and the drivage of roadways. Exceeding the maximum allowable level of its concentration in these headings makes it necessary to disconnect all machines until this concentration level is reduced. This leads to unscheduled downtimes of such machines, thus increasing the costs of their operation and decreasing their effectiveness. The paper demonstrates the results from the analysis of machine downtimes in the drivage of roadways, caused by excessive methane concentration levels. The analyses were based on the indications from the system for automatic monitoring of the ventilation parameters in this heading. The results obtained clearly demonstrated that exceeded values of methane concentration caused a series of unexpected downtimes in the drivage process. As a result, the process was disturbed and its effectiveness reduced. The presented analyses are one of the first to address the issue of how methane emissions affect machine downtimes. However, this phenomenon represents a major problem that needs to be addressed comprehensively in order to minimise the losses arising out of the necessary disruptions to the exploitation process

Evaluation of the Effectiveness of Employers and H&S Services in Relation to the COVID-19 System in Polish Manufacturing Companies

With the advent of the COVID-19 pandemic, companies had to adapt quickly to survive in the market. During this time, employers played a key role, along with employees involved in Occupational Health and Safety (OHS) activities, as they were responsible for implementing the recommendations of the European Commission. There is no unambiguous definition of OHS in Polish legislation. It is assumed that it is a set of rules defining the manner of performing work, and above all, a method of providing employees with working conditions so that their performance is safe and hygienic. Responsibility for the health and safety in the workplace is imposed on the employer by the legislature. Thus, effective health and safety training is an essential element of the success of any properly operating company. In the literature, no studies have been identified that evaluate the effectiveness of actions during the COVID-19 outbreak. The aim of the article is to present the actions of Polish employers along with their effectiveness assessment related to the protection of employees during the COVID-19 outbreak. The article presents a proposal for conducting remote OHS (Occupational Health and Safety) training using the platform Moodle. The created course was implemented during OHS training conducted in a selected manufacturing company. At its end, an evaluation of the course was carried out, and the collected opinions of training participants allowed the formulation of interesting conclusions, which became the contribution of this paper. The authors pay special attention to three main points of the work. The first is the form of training, which gives the possibility to conduct training at a distance while maintaining its effectiveness. The second important point is the mandatory feedback of the trainees, ensuring the possibility of continuous improvement and quality enhancement of both the program and the form of training. The evaluation was developed on the basis of the extended Kirkpatrick model, which is a completely new approach to OHS training evaluation. The third point emphasized by the authors is the possibility of precise adaptation of the training to other plants and even industries. Therefore, it can be concluded that the course developed by the authors is a very interesting and practical didactic tool with great implementation potential