Stripping modes
Dry thermomechanical stripping by cryogenic nitrogen jet

The choice of certain parameters (set pressure and temperature, firing distance, etc.) defines the state of the nitrogen at impact: liquid or gas. Figure 3 shows a high-speed camera image of the jet. Three morphologies can be distinguished along the jet:

• the jet, at high speed and under pressure, is coherent at the nozzle outlet;

• it then becomes two-phase with a mixture of dense packets of N₂ expanding into a fluid N₂ + air ;

• then dissipates as a fog, eventually mixing with the surrounding air.

Depending on the characteristics of the coating to be stripped and the choice of process parameters, several stripping modes are possible.

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