Assessment of External Sprayer Cleaning Efficiency by Comparing Different Cleaning Devices, Sprayer Tank Materials and Operators

The external sprayer cleaning is an essential procedure to minimize possible chemical contamination for both the environment and operators. The cleaning efficiency can be affected by the type of cleaning device, the sprayer architecture, and its component materials but also by the skills of operators. For these reasons it is important to investigate the effect of different variables on the potential decontamination of external sprayer surfaces. A new method aimed to evaluate the external sprayer cleaning efficiency in a simple and cost-effective way was tuned. It foresees the i) contamination of the sprayer applying copper oxychloride solution uniformly on the sprayer under controlled laboratory conditions and then ii) the external sprayer cleaning using a fixed volume of pure water. The cleaning efficiency was obtained measuring the amount of copper removed compared to that initially applied. Three different cleaning devices were compared (spray gun, long-range spray gun and lance) and then the operating parameters, namely nozzle size (1.0, 1.2, 1.5 and 2.2 mm in diameter) and spray pressure (0.3, 1.0 and 1.5 MPa) were also investigated for their possible effect on cleaning efficiency. Finally, the effect of tank materials (fiberglass vs. polyethylene) and operator were also tested. Results underlined the effect of nozzle size on the cleaning efficiency while the cleaning devices did not show significant differences. Furthermore, the cleaning efficiency resulted correlated to the roughness of tank materials while no effect of operator was detected applying the same procedure for cleaning.