The SBG contains a number of cartridges of equal size. One type of cartridge is filled with specific LiOH granules according to an Airbus Defence and Space specification, the other type is filled with activated charcoal and catalysts.
During the submerged periods of the missions, the LiOH cartridges are changed whenever the CO2 level in the confinement approaches the allocated limit. The saturated LiOH can be recycled ashore so there is no waste. The activated charcoal filters have to be replaced only after longer periods of time.
The Contamination Control Assembly (SBG) removes carbon dioxide and acid gases, by means of a chemical reaction with lithium hydroxide (LiOH), along with odours and off-gassing products, by means of activated charcoal filters and catalysts.
It also particulates and aerosols by means of a particle filter, which prevents LiOH dust from leaving the filter.
For installation of an SBG on a submarine, the ventilation system provides a bypass airflow to be drawn through the SBG, i.e. the SBG itself is a passive unit without fans, controllers or sensors.
A LiOH cartridge consists of a stainless steel housing, containing the filterbag inside and a plastic cover on each end of the housing.
For transport and storage it is sealed in an evacuated compound foil and is packed in a lightweight plastic container. Proper evacuation of the foil ensures the correct handling of cartridges and full performance, and the packaging is approved according to the German law for transport of caustic materials.
The Contamination Control cartridges consist of the same components as the LiOH cartridges. They are filled with different types of activated charcoals and catalysts according to customer requirements.
The reuse of the LiOH cartridges is recommended after recycling of the material at Airbus DS.