Analisis Laju Kristalisasi Es pada Cetakan Mesin Es Balok dengan Menggunakan Brine

Abstract

Block ice machines are widely used for fish preservation because they are practical and efficient. The block ice machine operated at Shipbuilding Institute of Polytechnic Surabaya (PPNS) previously had limitations in its mold design, so that the ice freezing process was not optimal and could not be completed on schedule. This study analyzes the ice crystallization process in ice block machine molds using brine as a secondary refrigerant. Brine has a lower freezing point than pure water, enabling it to reach low temperatures without freezing and accelerating the crystallization process. Two-dimensional numerical modeling was performed using Ansys Fluent with the Volume of Fluid (VOF) and Solidification/Melting models. The simulation focused on Brine conditions with an initial temperature of 10 °C and a salt concentration of 23.3%. The results showed that the freezing process began at 15 hours in the water domain in direct contact with the mold. The water froze completely at 18 hours with a temperature of -0.39 °C and a Brine temperature of -4.39 °C. At the 30th hour, the water/ice temperature reached -6 °C in the center of the domain and the brine temperature reached -9.6 °C. These findings confirm that brine effectively improves the efficiency and performance of block ice machines.