This paper presents an original method for producing three-phase jet to enable efficient treatment of technical surface using the Sandbot apparatus. Exemplary results of studies describing the geometrical structure of machined surfaces in the context of their quality grading.The stream of three-phase (air-water-abrasive) generated in innovative Sandbot devices [Prazmo 2012] is a modern and high-performance tool for dust-free surface treatment technology. Sandbot equipment enables the use of a variety of abrasive materials [Praźmo 2010, Sobczak 2013] including quartz sand (silica). Quartz sand may only be used in methods for wet and damp air in accordance with applicable in Poland guidelines contained in the Regulation of the Minister of Economy, Labour and Social Policy on occupational health and safety when cleaning the surface, spray painting and thermal spraying [Regulation 2004]. Furthermore, it describes the construction, operational and technological parameters and the area of innovative Sandbot devices, patented, designed and manufactured in Poland. These devices are intended for dust-free and high-performance cleaning of technical surface by the air-water-abrasive stream. They are used especially in industry, construction, and services.