Modeling flow and heat transfer in a scraped surface heat exchanger during the production of sorbet

A computational fluid dynamics model was implemented for studying the production of non-aerated sorbet in a scraped surface heat exchanger under different operating conditions. The coupled problem of fluid flow and heat transfer is solved by taking into account realistic values for the product physical properties as well as its complex rheology. The mathematical solution of the coupled problem represents a challenging task, among other reasons by the strong influence of temperature on product physical properties and rheology due to phase change. Fluid flow, heat transfer freezing and viscous dissipation phenomena are analyzed locally in the heat exchanger. The modeling approach is consistent, as indicated by comparisons between model predictions of the temperature profile along the heat exchanger and available experimental results.