Breathable Air In A Refuge Chamber

The underground personnel should be able to access a safe location if an undesirable atmosphere develops due to a fire, toxic gas release or other dangers. As an alternative to evacuation, shelter rooms provide a safe place away from outside hazards. For this reason, AYSAN Refuge Chambers are equipped with two different standard breathable air sources.

1-Compressed Air

Compressed air is atmospheric air from above pushed through pipelines by a compressor into the bunker. It has a filtration system consisting of a water separation filter that prevents water from entering the chamber, a coalescing filter that removes fine water and oil particles, a pre-filter that removes large particles and an absorber filter that removes diesel particles, very fine oil particles. After filtration, the air is passed through the regulator and automatic silencer (muffler to reduce noise) before reaching the interior chamber. 

To keep the refuge chamber under positive pressure, the internal ball valve must remain slightly open when the refuge chamber is in standby mode. Positive pressure ensures that toxic gases do not enter during entry or exit in a smoke-filled environment. Compressed air will also keep the internal environment dry and clean. 

2-Scrubber System & Oxygen Cylinders

The scrubber system is designed to purify the air in confined spaces where human life must be supported for a certain period of time. The aim is to reduce the risk of carbon dioxide and carbon monoxide poisoning by removing CO₂ / CO from the air in the refuge room. The front panel of the Scrubber System also features internal lights, external flashers, siren, manual keys as well as an inverter/charger switch and battery monitoring display. 

Scrubber System is used together with oxygen cylinders. Carbon dioxide is damped using AYSAN CO₂ cartridges which must be replaced when cleaning capacity is reduced. The chemical cartridge should be replaced when the digital gas monitor or manual gas measuring tubes are at or above 1% CO₂ level. 

Through a catalytic process, carbon monoxide is removed from the air. The air is passed through a scrubber chemical that converts carbon monoxide into CO₂ and H₂O. The carbon dioxide produced is then removed with soda-lime. 

AYSAN Refuge Chambers have breathable oxygen cylinders with a minimum capacity of 8500 litres for each person. Oxygen is supplied from the cylinder directly to the safe haven through a medical grade oxygen regulator. The number of cylinders required is based on the capacity of the refuge room and MSHA standards which specify 37 litres per person per hour for minimum safe holding time.