| 摘要 |
A method for pickling or descaling a concrete surface employing at least one jet of liquid nitrogen at cryogenic temperature below −100° C. at a pressure of at least 500 bar, distributed by the discharge orifice of at least one nozzle for distributing the jet of liquid nitrogen. At least a portion of the distributing nozzle is protected by a resistant material haying a hardness of at least 7 on Mohs' scale. Preferably, the resistant material is deposited externally on at least a portion of wall of nozzle. Advantageously, the material is selected from tungsten carbide, boron carbide, titanium carbide, silicon carbide, cubic boron nitride, alumina and corundum. |
