The formation of fouling layers during the thermal treatment of products is a severe problem for the food industry. These layers can lead to a drastic increase in resistance to heat transfer, thereby decreasing the thermal efficiency of equipment such as heat exchangers. Furthermore, the stringent requirements for quality and hygiene in food processes require regular and effective cleaning of production lines. Costs are thereby incurred for detergents, rinse water, disposal of spent solutions and energy. This paper considers a method for optimizing the cleaning process with respect to duration and energy consumption.
The focus of the work presented here is set on industrial cleaning in place (CIP) procedures in the food industry. Extensive work has been done in this field to shed a light on the parameters governing these processes. Though a huge number of scientific papers are available, a detailed explanation of all aspects important to understand cleaning processes is still missing due to the large number of parameters to be considered (Fryer et al., 2006). Consensus can be stated about the general factors of influence in cleaning procedures. For closed equipment, they can be described using the extended Sinner circle as a system dependent on six variables (Wildbrett, 2006). These are the kind and condition of the soil, the design of the plant as well as time, chemistry, mechanics and temperature as variables of the cleaning solution.