The dry ice blasting machine contains a dry ice pellet tank and a dosing unit which doses the dry ice pellets into the jet of compressed air. By means of the compressed air the dry ice is transported through a special blasting hose to the blasting gun nozzle. In the blasting gun, the air stream is accelerated, and the dry ice pellets leave the nozzle of the blasting gun at very high velocity.
Cleaning Effect The cleaning effect of dry ice blasting is based on three principles:
• Thermal Effect: The dry ice pellets have a temperature of -79°C/-110°F, and impurities are therefore cooled down drastically; the impurities shrink and loosen due to different thermal expansion coefficients.
• Kinetic Effect: When the dry ice pellets leave the blasting gun nozzle they have high kinetic energy and strike the impurities at a speed almost corresponding to the velocity of sound.
• Sublimation Effect / Volume Expansion: The dry ice pellets are being pressed into the brittle impurities and sublimate immediately on contact. The resulting volume increase by a factor of approx. 700 contributes to tearing away deposited dirt.
In some cases the thermal effect will be the most significant factor, in other cases the kinetic effect will be the most significant factor.