Pulsed flow in clean-in-place sanitization to improve hygiene and energy savings in dairy industry

摘要

Demand for dairy products has increased and sanitization is key to food security of this products. Thus, this work investigated the cleaning-in-place (CIP) with pulsed flow in the sanitization stage on stainless steel surfaces contaminated with raw milk compared to CIP with stationary flow for hygiene and energy saving purposes. In addition, fluid dynamic behavior in geometries typically found in dairy pipelines was investigated and energy consumption estimated. For this, a CIP prototype was used, where a straight cylindrical section and an elbow were subjected to natural contamination with raw milk and later sanitized, evaluating the waviness and period effects on the pulsed flow through the central composite design. The dynamic fluid behaviors of the stationary and pulsed regimes were studied using computer simulation. The results showed that both variables were significant for cell removal. However, the reduction in colonies was more significant in the straight cylinders compared to the elbow. Larger waviness and shorter periods promoted higher cell removals due to the occurrence of annular effect and its frequency. Pulsed flow associated with computational fluid dynamics showed improved sanitization efficiency in difficult reach places and reduced energy consumption.Practical applications Strategies to reduce losses and to guarantee food safety are essential. Pulsed flow sanitization can be used in dairy industries to improve cell removal in difficult-to-access geometries during sanitization, to reduce energy consumption and time spent compared to the stationary flow process, commonly employed in dairy. In addition, this change is attractive, as it can be made with only adjustments to the control system, not necessarily requiring new equipment.