Areas within which could arise explosive atmospheres having high concentrations, therefore requiring special precautions so as to guard the health and safety of concerned employees, are considered to be dangerous. If the electrical equipment used in these hazardous locations is not properly selected and installed for operating in explosive atmospheres, they are likely to generate an ignition and to result in explosion type events with significant environmental and material damages and, moreover, with human victims. Being an extremely difficult field to manage and having major importance, explosion prevention requires quality decisions. The reaching decision person must choose the best solution for putting into operation electrical apparatus in explosive atmospheres, taking into account certain factors, parameters, and the requirements for explosion protection and safety. Nowadays, special IT programs-decision support systems provide assistance for the reaching decision persons from a wide variety of domains. Explosion prevention shall not make an exception, especially because it firstly aims to improve the occupational health and safety of workers who operate within potentially explosive atmospheres. Taking into account the foregoing, the current paper presents the development and operation of a decision support system (DSS) for managing the selection and installation of explosion-proof electrical apparatus which are supposed to be used in atmospheres with explosion danger caused by burnable gases, liquids, vapours or mists.
During the development of an underground explosion phenomenon, due to the energy of dynamic wave, important mechanical effects are registered both in the affected mine workings and in ventilation constructions (stoppings and seals, ventilation doors, regulators and air crossings). An explosion directly affects the ventilation network by modifying specific operational parameters of the main fans. This creates a different natural post event repartition of the air flows, at the branch level. In order to ensure safety conditions after the event, it is necessary to restore the ventilation network. This complex process is based on critical pathways, for whose identification were first established ventilation constructions in relation with their emergency level. This paper presents the process for restoring a mining ventilation network affected by an explosion, following the determination of critical pathways, through successive steps for restoring the ventilation in circuits affected by the wave front. For presenting these steps and for highlighting obtained results, a case study was conducted, based on a hypothetical, medium intensity explosion scenario, produced in the underground of Uricani coal mine, a mining unit in the Jiu Valley carboniferous basin, Romania, using 3D CANVENT specialized software for modeling, simulating and solving ventilation networks.
In industrial plants many types of combustible dusts are generated, processed, handled and stored. When ignited, they can burn rapidly and with a considerable explosion force, when mixed with air in proper proportions. This is the reason why adequate precautions have to be adopted, to ensure all equipment is appropriately protected so that the ignition likelihood of the explosive atmosphere is diminished. Explosion preventing and protection precautions aim to stop explosion occurrence, by eliminating or avoiding the conditions leading to explosions. The paper presents methods of determining dust explosion characteristics and combustion as well as their importance for a proper development and selection of prevention and protection measures. Once known, the protection/prevention measures can be correlated with the safety characteristics. For explosion protection and prevention a series of minimum mandatory requirements have to be fulfilled, for a safe handling and processing of solid materials having fine particle dimensions, among which some are mentioned: knowing the characteristics influencing safety, control and monitoring dust releases in technological processes, installations design for migrating and accumulation of dusts, respectively implementing a rigorous cleaning program at workplaces.
The simulation of different situations that may occur in the operation of the mine ventilation network is performed on its virtual model, developed and optimized using dedicated software. Depending on the chosen scenario, on the network model are applied a number of changes (addition of new ventilation workings, addition / removal of branches and nodes, changes in aerodynamic parameters: pressure, air flow driven by the fan etc.), the ultimate goals being: to assess how the new model obtained respond to anticipated requirements, diagnose of existing or potential problems, providing a quick feedback to the operator by making available all the data necessary for decision making process. The complexity of the simulation lies in the need to execute a number of operations due to changes of the network structure and symbolism carried out on the virtual model. This article aims to simplify this process through automation and efficiency using software subroutines, subroutines containing the entire chain of operations performed for each step of the simulation, in order to reduce the simulation time and the level of complexity required for understanding the phenomena that occur in the mine ventilation networks.
In the process of underground coal mining a complex network of vertical, horizontal and inclined mine workings with the purpose of extraction, transportation and evacuation to the surface are utilized. The mining workings are also being utilized for ventilation network system, which is also used for ensuring the oxygen supply necessary for workers, as well for diluting explosive gases and/or toxic substances and, ultimately, for exhausting the heat resulted from underground workings. For air flow pumping, special fans, of high capacity, located at the surface of the main ventilation stations are used. The fan operating mode depends on aerodynamic parameters and also on the structure of the ventilation network. Knowledge of specific local network parameters leads to the optimization of air flow distribution. The novelty presented in the paper consists in analysing and optimising the complex ventilation networks of Lonea mining unit, based on the depresiometric, flowmeters measurements and the status parameters specifics to each branch. Worldwide, in high developed mining countries, solving a complex ventilation networks it's being carried out with the help of specialized software such as VentSim, VentGraft, VentPri, 3D Canvent etc., through discontinuous operating at the mining unit quarter or to a distant location, where upon the results obtained are presented to the ventilation specialists. The complex ventilation network afferent to Lonea mining unit was rendered, fixed and optimised, up-to-date, using 3D Canvent software.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.