Описание

Oxygen reduction systems

·         Protection concept.

·         System description.

·         Use in occuppied areas.

·         Cost  and availability.

Concept -Firepass:

·         No fires are possible in an area containing a reduced oxygen level.

·         A inerting atmosphere is generated.

·         The oxygen level is set to 14-15% in the room.

·         Air with an oxygen contents of 10% is injected in the protected room. (Others use injection of pure nitrogen).

Uses:

·         Automatized car parks.

·         Cold rooms. –Computer rooms.

·         Museums and archives.

·         Storage areas, silos…

Conditions that make these systems best options:

·         Large spaces that do not allow for large storage areas.

·         Where the rooms are very well sealed and it is not possible to install pressure relief dampers.

·         Where fire incidents are to be reduced to a minimum.

·         Where continuos inerting or low oxygen levels are beneficial.

Oxygen reduction systems

Features:

·         Oxygen is removed together with other air components andthe resulting nitrogen enriched blend is introduced in the room.

·         Power consumption depends on the room sealing.

·         Initial time is required before protection conditions are reached (1 – 2 days)

·         Suppression modes are possible with auxiliary storage ofhypoxic air.

·         Multiroom protection is possible when unit working time needs do not exceed 24h.

·         Oxygen concentration in the hypoxic stream depends on thepressure settings of the compressor and the oxygenenriched stream.

Design parameters

·         Leakages must be minimized to reduce working time of systems.

·         Where continuos access is likely it is recomended tointroduce dual acces or curtains (vehicles).

·         Air conditioning systems must be closed systems.

·         Typical air exchange values range1-3% air volume perhour.

Use in occuppied spaces:

·         The level of oxygen available is equivalent to heightsranging 2500-3000 m.

·         These systems are used for training of athletes.

·         It appears that these systems are safe for people.

·         But health and safety regulations generally refer to oxygenconcentration and not to oxygen available.

Use in occupied areas:

·         Regulations in Spain requires a minimum of 18% oxygen concentration.

·         OSHA: atmosphere with less than 19.5% are considered tobe oxygen deficient.

·         In Germany, it is allowed to work in reduced oxygenconcentration atmospheres considering specific maximumworking periods and periodic medical examinations.

·         LPG will offer a technical report for obtaining thepermissions of use.