Heat transfer analysis in a heat exchanger with two coaxial tubes for sustainable aseptic processing of foods

Abstract

Thermal-based approaches in food sterilization techniques principally utilize the heating process until the desired sterilization level of the food can achieved. More specifically, aseptic processing allows for a more cost-effective and time-efficient method for preserving food without degrading the food quality. In this work, we propose a heat transfer analysis of a scraped surface heat exchanger with two coaxial tubes that provides a simplified prototype of a sustainable aseptic processing system. The heat exchanger is installed with scraped blades to allow a stirring mechanism that can only oscillate back and forth at certain angles called oscillating angles. In this simulation, water and solid food particles are put in the system. Moreover, simple regression models are used to find the relation between the mechanical properties of the stirring process with the heat transfer properties. Therefore, experimental data of the temperature and heat transfer coefficient during the heating are used for model fitting. The model fit shows that the angle, frequency, and velocity of the stirring affect the temperature trend and the heat flow rate inside the system. Establishing a comprehensive heat transfer modelling can help to improve the traditional sterilization approach to focus on optimizing energy efficiency and reducing environmental impacts.