Mathematical modeling of continuous induction heating of sour cherry juice

Abstract

Induction heating is a noncontact heating method that enables heating of ferromagnetic materials. In this study, continuous induction heating system was custom set up and experimental and numerical results were compared. Sour cherry juice was heated to a target temperature value (75 C) at three different flow rates (200-250-300 ml/ min) and three different set pipe wall temperatures (80-90-100 C) in experimental study. COMSOL Multiphysics 5.2 was used to solve mathematical models and visualize temperature distribution during heating and flowing. Magnetic field, heat transfer, and laminar flow physics paired each other in the model. It was concluded that the time-dependent variation of the sour cherry juice output temperature was successfully predicted by the model developed for induction process conditions. The developed models could be used to estimate process time, temperature history of materials, and effect of flow rate on heating rate any time during the continuous induction heating process.Practical applications: Thermal processes applied in the food industry are aimed to inactivate the microorganisms in the food, to protect the nutrient content, and to have high energy efficiency. Conventional heating methods have a negative effect on the nutrient content of foods and the energy efficiency of the heating process due to long processing times. The advantages of induction heating are that it is a novel heating method, highly energy efficient, and performs heating process in a short time. In this study, a laboratory-scale continuous induction heating system to heat a liquid food product was established and numerical modeling of the heating process was performed. The obtained model will be an important data for installation of the continuous induction heating systems, scale-up in the continuous induction heating systems, and prediction to effects of the process parameters.