The combination of two different blasting methods presented here consists of compressed-air blasting in connection with hydro-jetting and it is called “µ-jet© method”.
- The abrasive/mixture of compressed air is led – as usual – from a pressure blasting pot to a jet nozzle (dry jet nozzle) and is pre-accelerated. Behind this jet nozzle a hydro-jet is added in a secondary chamber.
- The abrasive/mixture of compressed air is post-accelerated with the hydro-jet in the second nozzle (output nozzle) for the second time.
The high pressure of the hydro-jet (up to 2,700 b) enables to reach very high exit velocities of the abrasive.
This is also because of the fact that an abrasive grain for blasting can be caught and accelerated more easily by a denser carrying medium like water than by a comparably less dense carrying medium like air.
The kinetic energy of the abrasive increases to the square with the same mass at increasing speed. In case of doubling the speed quadruple of the kinetic energy will be reached, and in case of tripling even nine times of the kinetic energy will be achieved.
Due to the high kinetic energy of the abrasive and the thus resulting high abrasive performance this combined method is applied in the field of industrial corrosion control and in ship building.
Section of a µ-jet© nozzle
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