Improving the hygienic design of closed equipment

Maintenance of proper hygiene in closed process equipment is in many ways a complex task. The interaction between the physical design and the nature of fluid flow is of main concern. During cleaning the main performance of the flow is to bring cleaning agents in the right doses to all parts of the process plant. In turn the adhesion mechanisms between the soil and the surface of the process equipment must be overcome. In closed processes validation proves rather difficult, as inspection often is not possible. Hence, we benefit from a greater basic understanding of the influence of the mechanical cleaning action of fluid flow and the interaction between flow characteristics and soil attached to surfaces. Ideally, such information can be contained in fluid dynamics models or rules of thumb which can be used to assist in design of process equipment and when optimising cleaning procedures. Extending computational fluid dynamics models to be able to predict the cleaning efficiency in especially complex parts of process plants has excellent potentials for desktop improvements and computer pre-validation of the hygienic performance of process plants.