Non-newtonian flow and pressure drop of pineapple juice in a plate heat exchanger

Abstract

The study of non-Newtonian flow in plate heat exchangers (PHEs) is of great importance for the food industry. The objective of this work was to study the pressure drop of pineapple juice in a PHE with 50° chevron plates. Density and flow properties of pineapple juice were determined and correlated with temperature (17.4 ≤ T ≤ 85.8°C) and soluble solids content (11.0 ≤ Xs ≤ 52.4 °Brix). The Ostwald-de Waele (power law) model described well the rheological behavior. The friction factor for non-isothermal flow of pineapple juice in the PHE was obtained for diagonal and parallel/side flow. Experimental results were well correlated with the generalized Reynolds number (20 ≤ Reg ≤ 1230) and were compared with predictions from equations from the literature. The mean absolute error for pressure drop prediction was 4% for the diagonal plate and 10% for the parallel plate.