Modeling of the ViscoLine Annular Heat Exchanger

Abstract

The ViscoLine Annular heat exchanger (VLA) is a four annular concentric tube heat exchanger from Alfa Laval AB designed for processing mainly food products like purees. These type of uids are highly viscous and known as non-Newtonian. The VLA unit is a commercialized product although there is lack of information of how does the heat exchanger work with precision and thus, only rough estimations based on experience can be done for simulating the VLA behavior. In this project, a model of the VLA considering both heat transfer and pressure drops has been developed in order to obtain a reliable model of how the heat exchanger behaves when using non-Newtonian uids so it can further be used for commercial purposes within Alfa Laval AB. In parallel, tests on the VLA heat exchanger using the available uids; water and oil which are Newtonian uids, have been carried out to prove the validity of the elaborated code. These tests have been run in two different units. From an analysis on the results obtained from the code evaluation and a proper characterization of the non-Newtonian uids, the behavior of these uids in the VLA can be simulated. The results of this should conclude in a general correlation for the ViscoLine Annular heat exchanger when dealing with non-Newtonian uids. The model has been validated with regard to heat transfer. Pressure drop calculations agree with the measurements but there are issues that need to be followed closely: the singular pressure drop coe cients ( factors), the wall viscosity effect and the pressure drop calculations in one of the units.

Outgoing