In deep-underground mining shafts, main intake airways must maintain higher static air pressure than return airways to prevent poisonous strata gases from migrating into active work areas. If an automated sensor detects carbon monoxide exceeding safety thresholds in an intake shaft, the main ventilation fan switches to extraction mode, and downstream regulator doors automatically seal. This immediately reverses the pressure differential across the sector, turning the intake shaft into an exhaust chimney to purge smoke directly to the surface.
Based on the passage, which of the following is a logical conclusion regarding the ventilation system during an emergency response?
- AMiners stationed in active work areas must activate auxiliary compressed-oxygen packs because downstream regulator doors are sealed.
- During an emergency purging cycle, the intake shaft operates at a lower static air pressure than the return airways.Cevap
- CThe migration of poisonous strata gases into active work areas is the primary trigger that switches the ventilation fan to extraction mode.
- DDownstream regulator doors seal automatically to keep the intake shaft at a higher static air pressure than active work areas.
Cevap
During an emergency purging cycle, the intake shaft operates at a lower static air pressure than the return airways.
The passage establishes that under standard operations, intake airways maintain higher static air pressure than return airways. When emergency extraction is activated, the system explicitly 'reverses the pressure differential across the sector.' Logically, reversing this condition means that during the emergency cycle, the intake shaft operates at a lower static air pressure than the return airways.
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Anahtar Kavram
Synthesizing multi-condition relationships to deduce an unstated physical state.