Managing an oxygen enrichment facility at 5,000m requires PSA cycle control, room O2 mass balance calculation, and CO2 monitoring — all with the reliability constraints of a remote, mission-critical deployment.
The PSA cycle alternates between two columns. Column A adsorbs nitrogen at elevated pressure while Column B regenerates at low pressure by venting. Cycle timing determines output oxygen concentration — longer adsorption produces higher purity but lower flow rate. A typical room enrichment system targets 27–30% O2 in the supply stream, blended with room air recirculation to achieve the target room concentration.
The room O2 mass balance determines how much enriched air flow is needed for a given room volume and occupancy. At steady state, the enrichment input must offset the oxygen consumption by occupants (approximately 0.3–0.5 LPM per person at rest) and the dilution from any ventilation air exchange. For a 40 m³ room with 6 occupants at 5,000m, targeting 28% room O2 requires approximately 80 LPM of 30% enriched air continuously.
CO2 is the parallel concern. Six occupants produce approximately 1.5 LPM CO2 per person — 9 LPM total in a 40 m³ space. Without active exhaust, CO2 would reach 1,000 ppm in under 30 minutes. The exhaust rate must remove CO2 at least as fast as it is produced, balanced against not exhausting the enriched O2 supply.
The Neometrix OEF control system manages all of these variables — PSA cycle timing, O2 sensor feedback, CO2 monitoring, exhaust control, and power management — in a PLC architecture designed for unattended operation in sub-zero Himalayan conditions.
Key sensor requirements: electrochemical O2 sensors (0–30%, ±0.1% accuracy, temperature-compensated), NDIR CO2 sensors (0–5000 ppm, ±50 ppm), pressure sensors on PSA columns, and flow measurement on the enriched air distribution circuit.
Safety interlocks include: high O2 alarm at 30.5% (fire risk threshold), low O2 alarm at 25% (enrichment failure), high CO2 alarm at 1,000 ppm, power failure alarm with automatic transfer to backup, and PSA column over-pressure protection.
→ https://neometrixgroup.com/products/oxygen-enrichment-facility
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