Abatement of the effect of slug in ventilation shafts by means of condensed moisture control and ventilation system management in mines

The article presents the developed method to control condensed moisture and ventilation system parameters in mines to minimize the slug or the blanket-effect in ventilation shafts. The model results on nonsteady processes of the blanket-effect formation are described, and the characteristic times of condensed moisture accumulation in a shaft depending on the return air flow velocity, location of a water production source and its intensity are calculated. In terms of a copper–nickel mine, the quantitative evaluation is performed for the shift of the main fan set point under the incremental air drag generated by condensed moisture in the shaft. It is shown that abatement of the blanket effect on the mine ventilation system should include activities targeted at reduction in condensed moisture accumulation in the shaft. The practicable methods of the main fan performance management with a view to minimizing the slug effect in the shaft are identified. The choice of a particular method depends on the maximal fan capacity and on the actual values of water inflows in the shaft. It is said that if a fan has a reserve to operate at an increased capacity, then the blanket effect minimization involves an increase in rotation frequency of the impeller to shift the set point of the fan rightwards the influence zone of the blanket effect. If a fan has no reserves to overcome a potential slug barrier, while beyond the barrier the fan is capable to operate stably at a very high air delivery, it is advised to reduce temporarily the rotation frequency of the impeller in order to discharge moisture to a sink hole and, then, to recover the previous frequency, which can eliminate potential formation of a slug. The shift of the fan set point is modeled for each method application.

Kolesov E. V., Semin M. A. Abatement of the effect of slug in ventilation shafts by means of condensed moisture control and ventilation system management in mines. MIAB. Mining Inf. Anal. Bull. 2024;(5):62-78. [In Russ]. DOI: 10.25018/0236_1493_2024_5_0_62.

The study was supported by the Russian Federation for Basic Research, Project No. 19-35-90076, and by the Ministry of Science and Higher Education of the Russian Federation, R&D Project Registration No. 122030100425-6.

E.V. Kolesov¹, Engineer,  e-mail: kolesovev@gmail.com, ORCID ID: 0000-0002-0755-7405,
M.A. Semin¹, Dr. Sci. (Eng.), Academic Secretary, Head of Laboratory, ORCID ID: 0000-0001-5200-7931,
¹ Mining Institute of the Ural Branch of the Russian Academy of Sciences, 614007, Perm, Russia.

E.V. Kolesov, e-mail: kolesovev@gmail.com.

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