The paper presents results of testing the resistance of chain wheels made of alloyed austempered ductile iron (ADI) with various content of retained austenite and subjected to shot peening, to the dynamic and abrasive wear by solid particles. The impact of the additional environmental factor—external dynamic forces—accompanying the operation of the chain wheels in the presence of the quartz particles has a synergistic effect on the abrasive wear in the contact area between the wheels and the chain links for all the considered variants, except for the ADI with the structure of the upper ausferrite. Based on the results obtained, it was found that the abrasive wear by solid particles increased and that the hardness of the surface layer of the chain wheels subjected to shot peening decreased. The relative increase in the wear ΔV_DYN/δ_MAX,(A), representing the share of the additional dynamic force in the process of wear, was in the range of 16–40% for the group of tested cast iron ADI not subjected to shot peening, while for the shot peened—in the range of 16–64%. Demonstration of phase changes during the operation of chain wheels and the change in their intensity depending on the combination of environmental factors is the work novelty. In the opinion of the authors, the presented results will be of great practical importance as they will allow to increase the knowledge on the proper selection of ADI cast iron for environmental conditions.

The article discusses the process of designing and testing as well as their results, carried out in order to increase the efficiency of axial fans, implemented as part of the European project INESI. Modifications of existing solutions based on rapid prototyping methods were presented. Scanning, FEM and CFD numerical calculations and 3D printing were used for that purpose. Rapid prototyping involved the use of a steel blade base and 3D-printed complex aerodynamic shapes that were bonded to create completely new blades. After their installation on the new rotor, enabling the angle of attack adjusting, a number of verifying tests of the fan were carried out. The solution was successfully tested and the results are discussed in the article.

The article discusses the current research and development projects realized by KOMAG within the European INESI project, the aim of which is to increase the effectiveness of auxiliary ventilation in underground mines. They mainly focus on improving the fan operational parameters by modification of rotor's blades. Modification of the blades by 3D printed and stuck inserts with supporting role of CFD modelling are discussed. The results of testing the fan before and after modification, are presented.

This paper presents a conceptual design for a technological installation aimed at mitigating ventilation air methane (VAM) from coal mine exhaust shafts, offering combined heat and power generation. It addresses the challenge posed by low methane concentrations (below 0.7%), which preclude direct combustion. To overcome this, the proposed concept involves diverting a portion of the VAM to a combustion chamber of the power boiler dedicated to co-combustion with flotation concentrate suspension, which is properly prepared for feeding into the combustion chamber. The heat generated in the power boiler produces steam to drive a turbine generator for electricity production. Back-pressure steam from the turbine can be utilized for district heating or as a thermal energy source for various industrial processes, optimizing the plant’s energy efficiency and reducing its environmental footprint. The feasibility of this technology hinges on its cost-effectiveness and energy efficiency. This aspect of efficiency has been outlined. An energy balance analysis, based on real emission data from a selected mine, is provided to determine power boiler efficiency, fuel consumption, and a VAM reduction rate. The forecast of the amount of energy produced was presented for a single installation with a grate boiler capable of co-firing fuels with a VAM flow participation of 25 m³/s. Such installations can be scaled to meet mine requirements, enabling the neutralization of VAM at a total capacity of up to 300 m³/s, which corresponds to emissions from a large ventilation shaft.