EXPERIMENTAL STUDY OF AERODYNAMIC INDICATORS AT PERMIABLE EXCAVATIONS IN MODELLING OF VENTILATION NETWORKS

Abstract

The article reveals issues of directing and controlling the air low supplied
to permeable mine excavations in ventilation networks through experimental studies
at mining and experimental rigs, determining the values of external and internal
air losses and aerodynamic resistances relating to the amount of air supplied to
permeable mine workings, the length of the mine excavations in permeable mines,
the state of binding between the workings and reduction of aerodynamic drag. The
research was made using a stand developed in laboratory conditions as well in natural conditions by means of a physical model made in accordance with the topology of the mine workings of the Zarmitan deposit. The loss of the air low in the mine depends on the degree of the excavation’ tightness, while the latter will depend on the values of aerodynamic resistance developing within the process of air movement in the excavation. Values of aerodynamic resistance, in turn, also vary depending on the level of leakage of the mine as well as on the of aerodynamic drag- and friction coeficients, and Reynolds number. The study revealed internal and external air losses at the points of contact of the mine workings. The need for various methods for the air low control in view of the losses’ prevention, has been proven by means of measurements and analysis. Also, the article presents effects from changes of aerodynamic parameters using sealing methods and agents that serve to increase ventilation eficiency of leaky mine workings with complex ventilation systems. Aerodynamic resistance during air movement within the elements of mine ventilation systems, local resistance and especially leaky sections of the ventilation network require continuous measurement of aerodynamic parameters. Broad use of the developed comprehensive approaches to improvement of mines’ ventilation system is being recommended in view to address the aerodynamic issues in the ventilation system of mines.