Cardox has a variety of different tubes for specific applications.
Tubes are filled with liquid carbon dioxide (exactly the same as
a fire extinguisher). When energized by the application of a small
electrical charge, the chemical heater instantly converts the liquid
carbon dioxide to a gas. This conversion expands the CO2 volume
and builds up pressure inside the tube until it causes the rupture
disc at the end of the tube to burst. This releases the C02 - now
660 times the original volume - through a special discharge nozzle
to create a powerful heaving force, at pressures up to 40,000 psi
(3,000 bar). This all takes place in milliseconds.
Carbon dioxide gas is an inert gas that is commonly used in fire
extinguishers, so it is safe to use without fear of generating secondary
reaction with gases in the vessel / silo. In addition, the quick
release of the gas refrigerates the discharge, bringing it to a
temperature low enough to avoid ignition of any air-gas mixture
inside the blocked vessel.