Oxygen from chemical reaction as a gas supply for oxygen rebreathers
Oxygen rebreathers based on a chemical process are among the oldest types. The system uses chemicals that absorb CO2 and generate oxygen. As early as 1930, a whole series of devices under the name Naszogen was put on the market in Germany. That success was not long-lasting because of the asbestos in the oxygen-generating cartridge. This system was later widely used by the Russian designers for the IDA series of rebreathers. Fenzy also makes units based on this principle today. The disadvantage is the exothermic reaction of the chemical, and the violent reaction with water. This explains why many accidents happened with these systems in the Russian army. Although the idea is excellent, the use for underwater use is limited to submarine escape systems. Smaller units used in mines also make use of this principle. Here are some examples of these types of systems.
The system used in many portable units such as the Russian IP4 is a system where CO2 is rapidly produced upon activation by breaking a container of sulfuric acid so that it is mixed with baking powder making CO2.
(H2S04 + K2C03 -> K2S04 + H2O + C02). This high dose of CO2 then reacts with the ‘O3’-scrubber and gets the scrubber going and O2 flowing…(addition by Anders Puranen, thanks)
Therebreathersite was founded by Jan Willem Bech in 1999. After a diving career of many years, he decided to start technical diving in 1999. He immediately noticed that at that time there was almost no website that contained the history of closed breathing systems. The start for the website led to a huge collection that offered about 1,300 pages of information until 2019. In 2019, a fresh start was made with the website now freely available online for everyone. Therebreathersite is a source of information for divers, researchers, technicians and students. I hope you enjoy browsing the content!