In submarines, oxygen for breathing is typically generated through a device called an "oxygen generator" or "oxygen-producing canisters." These systems are designed to replenish the oxygen supply for crew members during extended underwater missions.
There are two primary methods used to produce oxygen in submarines:
Electrolysis: Electrolysis is a process where water (H2O) is split into its components, hydrogen (H2) and oxygen (O2), using an electric current. The hydrogen is usually vented overboard, while the oxygen is collected and supplied to the submarine's crew compartments. This method is efficient but requires a power source, which is usually provided by the submarine's batteries or nuclear reactor.
Chemical Oxygen Generators: Another method involves using chemical oxygen generators, which contain a chemical compound that releases oxygen when heated. Sodium chlorate (NaClO3) is a common chemical used in these generators. When the chemical is heated, it decomposes to release oxygen gas (O2). The generated oxygen is then passed into the submarine's ventilation system to be distributed to the crew.
It's important to note that submarines also have systems to remove carbon dioxide (CO2) exhaled by the crew, ensuring a continuous supply of breathable air. These systems typically use chemical scrubbers or other technologies to absorb CO2 from the air.
The combination of oxygen generation and CO2 removal systems helps maintain a habitable atmosphere inside the submarine, enabling the crew to breathe comfortably during their underwater missions.