This invention relates to a continuous vacuum pan (also sometimes referred to as an evaporative crystallizer) for use in the sugar processing industry, and to a heat exchanger used inside the continuous vacuum pan. The invention also relaters to the heat exchanger as used in other applications in the sugar processing industry. The heat exchanger includes a massecuite flow path for conveying massecuite therethrough, and a heat transfer medium flow path for receiving a heat transfer medium to enable heat transfer to the massecuite flow path. The heat exchanger is characterized therein that a periphery thereof is surrounded by an insulated zone in order to prevent heat transfer from the heat transfer medium flow path to the environment.