Experimental study on the interaction of falling films and spray jets during cleaning

In hygiene-critical industries such as the food industry, there is great interest in designing needs-based cleaning processes with optimized parameters.Simulations of the cleaning processes can support optimization, but often take too long, especially regarding the spray cleaning of large containers.Simplified and semi-empirical prediction models can improve the situation but require a solid experimental basis.The present study addresses an important knowledge gap by investigating the cleaning of a swellable, food-related model soil with water by a spray that is superimposed with a falling film.The variation of the impact angle of the spray (30 ... 90), the pre-wetting time (0 s ... 120 s) and the nozzle pressure (1 bar ... 5 bar) reveals a wide range of possible effects.Compared to spray cleaning only, both an increase in the cleaning rate of almost 50% as well as a decrease in the cleaned area of about 80% were observed, depending on the parameter selection and focus of the analysis.