Heat transfer in a plate exchanger during pasteurization of orange juice

Abstract

The heat transfer film coefficient of orange juice (OJ) during pasteurization using a plate heat exchanger with intermating 316 SS plates was studied. Mathematical models to predict OJ heat transfer film coefficient are presented. The OJ density was measured using an in-line density sensor at pasteurization temperature and also measured off-line by hygrometer at different temperatures. The OJ viscosity was measured by an off-line instrument, in the temperature range from 5–90°C. The mean values of OJ density and OJ viscosity at 20°C were 1046.0 ± 3.6 kg/m 3 and 14.17 ± 4.75 mPa s, respectively. The values of heat transfer film coefficient for OJ varied from 983 to 6500 W/m 2 °C, whereas the water heat transfer film coefficient varied from 8387 to 24245 W/m 2 °C. This study has provided a suitable heat transfer correlation to predict the OJ heat transfer film coefficient as a function of its viscosity and the channel velocity, that is, this correlation is independent of the plate geometry, for varied conditions of OJ pasteurization process.