Application of Computational Fluid Dynamics to Improve Scraped Surface Freezer Operation for Producing Frozen Desserts

Abstract

Highlights Mixing, scraping, and freezing processes of a scraped surface freezer were simulated. The outcomes were validated by axial temperature and particle residence time. The computational results visualized complex flow patterns with recirculating zones. Abstract. With consumers becoming more aware of the health risks associated with obesity, the food industry has begun to seek better ways to produce healthier frozen desserts. Making such products has been a challenge, as it is difficult to control the taste quality of a product while also attempting to maintain its nutritional value and decrease the amount of fat and sugar it contains. The difficulty is made greater by a lack of understanding of the freezing process. Essentially, commercial ice cream products are crystallized inside a component called a scrape surface freezer (SSF), which contains a high-speed rotational beater, a dasher, and blades for mixing and scraping the ice cream mixture from the walls of the cylinder. In this study, the complex mixing, scraping, and freezing processes of an SSF were modeled using computational fluid dynamics (CFD) to evaluate and understand these processes virtually because they are extremely difficult to evaluate physically. Therefore, a CFD simulation model was developed to comprehend the complex nature of heat transfer and fluid dynamics. The computational outcomes were validated by means of two experimental comparisons: an axial profile of the temperature occurring inside the SSF and a profile depicting particle residence time. The CFD results aided in the visual identification of details pertaining to such flow patterns as high shear stress and recirculating zones. This study should provide a basis for the SSF designs based on advanced computational models, with the result being a more efficient, cost-effective way to produce healthier versions of frozen desserts. Keywords: Computational fluid dynamics, Food process, Particle tracking, Residence time distribution, Scraped surface freezer, Sorbet production.