Ice Crystallization in Ice Cream Manufacturing by Coupled Computational Fluid Dynamics and Population Balance Method

Freezing is the single most influential step of ice cream manufacturing. During freezing, multiphase flow, ice crystal nucleation and growth, phase change, and viscous shearing all play roles in ice cream crystallization. In this work, ice crystallization of a sucrose solution is investigated using a coupled computational fluid dynamics and population balance method. The dynamic freezing process that takes place in a scraped surface heat exchanger (SSHE) is simulated using a sucrose solution as a model material. Ice crystal nucleation and growth kinetics are described by population balance equations. Effects of multiphase, phase change, and shearing from scraping in a continuous freezer on ice cream formation are investigated, and the fluid flow, temperature distribution and ice crystal size are predicted. The method predicts trends similar to experimental observations, and provides insight into how processing conditions affect ice cream manufacturing.