Scaling-related phenomena during cleaning protein based soils in micro structured equipment

Micro structured equipment is prone to fouling and consequently micro components are often excluded as soon as fouling-prone fluids are present. With the availability of suitable cleaning strategies, the specific advantages of micro structured equipment could be exploited on a broader range. To investigate the transferability as well as differences and similarities of cleaning in macro and microscale components, cleaning tests of whey protein isolate based hydrogels are carried out in a flow channel with a one-dimensional micro structure. Initial results show the possibility of transferring well-established cleaning strategies from the macro to the microscale and allow the access to scaling-related phenomena. New methods were established such as the ability to quantify the changeable flow velocity during cleaning in microscale, as well as the quantification of the cleaning rate with temporal and local resolution via image analysis. The respective results are used for cleaning modelling with the model parameters serving as a criterion for tracking scaling-related phenomena. The geometry of a channel indicates a contrasting impact on cleaning performance, with regard to a reduction in channel height. Although a narrowing of the cross-flow section due to swelling of the hydrogels could lead to possible partial blockage, which significantly reduces cleaning rate, thus increases cleaning time. However, the narrowing of the cross-flow section also increases flow velocity and thus improves the cleaning rate, consequently leading to an improved cleaning performance. • Applying cleaning strategies from macro to micro scale shows scaling-related phenomena. • Swelling of the deposit becomes more decisive due to its blocking potential. • Quantification of the local cleaning rate is possible based on image analysis. • New calculation method for the shifting flow velocity via pressure drop. • Cleaning model designed for macro scale can be transferred to the micro scale.