Investigation heat transfer coefficient and heating surface area of shell and U tube heat exchanger: analysis and performance to cooling system on biodiesel plant

Shell and u tube heat exchangers (SUTHE) are a type of heat exchange equipment widely used in industry. SUTHEs have the advantages of lower operating costs and easy maintenance. Maintaining SUTHEs through continuous washing is important for the quality and quantity of production in biodiesel factories. The SUTHE being studied functions as a cooling medium for biodiesel products. Cooling water is on the shell side and biodiesel is on the tube side. This study will examine the cleaning of SUTHEs to remove silica scale caused by cooling water. The cleaning process uses a Clean-In-Place (CIP) machine at 80 °C with a 10% phosphoric acid solution and varies the cleaning time between two and ten hours. The volumetric flow rate of the cooling tower increased by 485.7%, the heat transfer coefficient increased by 5%, the heat load increased by 100%, and the heating surface area increased by 88.7%. Meanwhile, the biodiesel temperature decreased by 12.7%, and the cooling water temperature decreased by 23.8%. Since the results from the 10-hour cleaning process were the same as those from the 8-hour process, the investigation was halted after 8 h. It was determined that the results had reached a stable state with no further decrease in temperature after reaching 32 °C.