Modelling and control of plate heat exchanger with continuous high-temperature short time milk pasteurization process – A review

Abstract

Higher Temperature Short Time pasteurization (HTST) is favoured in dairy plants over other pasteurization techniques. Since the HTST approach preserves vitamins and improves sensory features in dairy products. An integrated milk plant comprises of storage tanks, plate-heat-exchangers (PHE), coolers, and transport-pipe-lines that needs mathematical modelling to learn the process-performance, parametric-sensitivity, operational-control for possible improvement and scale-up whose dynamics are unknown. Additionally, fouling of exchangers poses problems leading to abnormal flow and heat that make the pasteurization difficult to control. Material and energy balances of high-temperature short time pasteurization in heat-exchangers using first principle techniques are discussed. Development of biofouling inside the exchanger/holding tubes is considered for modelling, effective heat transfer and consequent operational controls. Closedloop control of pasteurization temperature using several strategies over the past few years has been discussed. This article presents a state-of-art review on the modelling of PHEs, fouling and identification of parameters from multi-input/output systems, milk process-simulators and also controller design for pasteurization process in the past twenty years by collecting 80 works of literature. A future direction of research is also provided in this work.

Keywords

• Mathematical modelling
• Process control
• PHE
• Pasteurisation process
• Milk