A measuring system for monitoring multi-nozzle spraying tools

Spray tools with multi-nozzle-arrays are used in a wide variety of applications. Monitoring the functionality of complex spraying tools with a large number of individual nozzles is a great challenge. For this purpose, we have developed a measurement technique based on the wetting pattern, which forms on a surface during spray impingement. To investigate the performance of this measurement technique we applied a spraying tool with nine external mixing air-water nozzles, the geometric alignment of which can be freely adjusted. In the first test series, the precision of the evaluation of the nozzle alignment is determined. The second test series focuses on the individual sizes of the wetted areas. Here the reproducibility, the influences of the operating modes and the nozzle type were evaluated. Subsequently, the functionality is tested in an exemplary test case in which two of nine nozzles were readjusted in a defined manner. Finally, the wetting pattern resulting from injecting a full spray is discussed and the necessary image processing steps are provided. In summary, this measuring system allows efficient, fast and cost-effective control and documentation of the alignment and functionality of spraying tools, thereby avoiding production downtime and related costs.