Micropore EAC SM0655C for military and professional use
The SM0655C is the new model number of the SM-0801C for military rebreathers.
ExtendAir® CO2 absorbents have been developed for use in military, commercial and recreational rebreathers. The main advantages of the cartridge technology are:
- Single use packaging
- Lack of dust compared to granules
- Water tolerance: no immediate "caustic cocktail" when wet
- Lowest work of breathing possible
- Excellent shock and vibration resistance
Micropore Extendair Cartridge, 125mm x 195mm with wide central bore (Model SM0655C).
The absorbent has many national defence applications including use for military Special Operations rebreathers, emergency and primary atmospheric control on submarines. Compared to the traditional granular carbon dioxide absorbents, it makes breathing up to 40% easier and provides up to 25% longer life support for any given weight.
ExtendAir® absorbent does not have the safety, storage, and loading problems associated with the granular absorbents. Granule absorbents form a powder when subjected to the shocks and vibrations of regular transportation, storage, and in-use scrubbing. The powder creates a dangerous chemical dust and settling in the scrubber canister, shortening the scrubbers’ duration and making breathing more difficult. ExtendAir® cartridges do not suffer from this type of degradation during transportation, storage or use. In addition, ExtendAir® absorbents for rebreathers offer a significantly reduced ‘caustic cocktail’ when compared to other absorbents. Operationally, it is superior since it takes mere seconds to load, reduces training time, is more reliable, and its single use packaging eases deployment logistics.
ExtendAir® cartridges are approved for use in combat diver rebreathers by the US Navy and several EU countries’ Special Forces. The absorbent is FDA approved for medical oxygen delivery systems.
ExtendAir® cartridges (EACs) are supplied in boxes of 4, and shipped with a minimum order quantity fo 8 EACs. On pallets, 384 EACs, comprising 96 boxes of 4, can be loaded onto a 1.2 x 1.2 x 1.6m pallet (weight 890kg).
Q:
How much better are Micropore ExtendAir Cartridges (EACs) performance compared to the same weight of high quality loose granular absorbent?
Answer:
Duration is improved 20% over granual media in rebreathers that have been optimised for EACs, such as the Incursion family of rebreathers.
Q:
How do Open Safety rebreathers achieve such low Work of breathing (WOB)?
Answer:
Professional engineering with proper Test & Evaluation achieves most of benefit as our rebreathers were designed from the ground up using a clean slate. Optimising performance and testing every single component. This enabled Open Safety to engineer in uniform air flow in the canister in order to reach optimal efficiency. Sheets of adsorbent material are wrapped around a core to form an ExtendAir® cartridge. The molded ribs in the material create channels through which the breathing gases flow. One of the unique features of an ExtendAir® cartridge is that the breathing resistance of the adsorbent can be precisely controlled by varying rib height and spacing. This controlled channeling of the breathing gases results in a very uniform reaction zone within the adsorbent.
Q:
How can you service a rebreather with Micropore EACs so quickly and don't need to spend time carefully repacking the scrubber?
Answer:
In a granular canister, gases seek the path of least resistance through the bed. The flow pattern can be very random and will certainly vary from person to person. Learning to load a granular canister requires instruction to learn the proper technique. Optimal loading of the canister requires tapping to achieve a uniform bed of granules. This takes time and can cause dusting of the adsorbent. All of this leads to variations in duration, wasted adsorbent and the potential for "caustic cocktail". In contrast to a granular system, ExtendAir® cartridges use channels, molded in at the factory that remain constant and controlled by the manufacturing process. The user simply places the cartridge into the canister, without any need for tapping or shaking as the canister is being loaded. As such, the duration variability due to irregular granule settling patterns, as well as variability due to individual loading technique are completely eliminated. Eliminating this variability will directly translate into longer minimum duration, and a +/-5% variation in duration at any test condition (granules can vary up to +/-30%).
Q:
Why is it important that these Micropore EACs are used with flow cones that aren't required in other rebreathers?
Answer:
An important concept to understand with ExtendAir® cartridge technology is that the gas flow distribution through the cartridge must be uniform in order for the system to perform optimally. For example, one way to visualize flow through an ExtendAir® cartridge system is to take a bunch of soda straws in your hand (50 or so). What would happen if you blew air down through a group of 5 straws? All of the air would flow down those five straws, and none of the air would flow through the other 45. The same thing would happen if you blew air into just one side of an ExtendAir® cartridge canister: all of the air would flow through that side only. The end result of this uniform flow is full use of the cartridge.
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