Innovative Insights into Scraped Surface Heat Exchangers (SSHEs): Working Principles, Improvements, and Applications in the Food Industry

Abstract Scraped surface heat exchangers (SSHEs) are widely recognised for their efficiency in handling viscous, crystallisation-prone, and fouling-sensitive materials. Their distinctive design enables continuous heat transfer while limiting fouling, which is essential for product quality and process efficiency in the food industry. This review primarily focuses on the fundamental flow and heat transfer mechanisms that govern their performance under food processing conditions. Based on these mechanisms, recent improvement strategies are discussed, including geometric optimisation, nanofluid use, and coupling with ultrasound or magnetic fields. Typical food applications such as oil and fat crystallisation, dairy processing, and beverage concentration are summarised through practical examples. Despite their advantages, SSHEs still face challenges such as high energy demand, scraper wear, and fouling under complex conditions. Future developments integrating multiphysics modelling, advanced design strategies, and intelligent monitoring are expected to enhance operational reliability, reduce energy consumption, and support scalable and sustainable food processing using SSHEs.