Determination of Narrow Airways in Ventilation Systems of Mines

The criteria of narrow airway assessment, indices of mechanical energy dissipation/loss, and power dissipation/loss, as well as indices of narrow airway assessment have been derived. Carrying out the ranking of narrow airways in different mine ventilation systems, it has been ascertained that legitimate is the assessment of a narrow airway based on the index of power dissipation/loss. When eliminating narrow airways adjacent to airways with diagonal streams, one should obey the adequate compromise between the postulate of economies and that of safety consisting in avoidance of directions destabilization - generating catastrophes - of the mentioned diagonal streams.