Risk-forming dynamic processes in units of mine hoists of vertical shafts

Abstract

Purpose. Estimation of risk-forming processes in operation of hoisting machines in vertical mine shafts. Methodology. Complex analysis of the results of theoretical research and experimental data of instrumental measurements of parameters of guide geometry, dynamic interaction of lifting vessels with shaft reinforcement, velocity diagrams of vessels, wear of reinforcement elements and deformation-strength calculations. findings. It is shown that dynamic processes in mine hoisting installations in operating and transition modes have a property of strong interconnectedness and cumulative strengthening of risk-forming phenomena in “lifting vessel - reinforcement” systems. The cumulative effect can occur when critical processes are interrelated in different units of a hoisting machine, even under the conditions that parameters of each process do not exceed permissible limits. This significantly increases the risk of an emergency situation when vessels interact with reinforcement guides under wear conditions during long operation. The means for reducing the level of risk of spontaneous accidents are provided, which ensure an increase in operation safety of hoisting complexes. Originality. In the paper on the basis of complex analysis of electro-mechanical processes in units of hoisting machines it is shown that the main risk-forming factors are: a non-smooth character of change of ascension velocity during the cycles of descent/ascension of vessels; load displacement in a vessel; tension imbalance of head ropes of multi-rope hoists; uneven wear of guides and buntons of reinforcement combined with local curvatures of guide profiles and disturbances in parameters of their track. In this case, the emergency dynamic state of the system can occur even when the parameters of associated processes are within permissible limits established by the current regulatory documentation. Practical value. Obtained results make it possible to comprehensively assess a technical state of “hoisting machine - rope - vessel - reinforcement” systems during operation of mine hoists and their expert examination and to establish objective causes of emergencies and their premises, develop recommendations that prevent exceeding the permissible risk depending on operating conditions.