A novel TLC based technique for temperature field investigation in MD channel

The importance of temperature polarisation phenomenon in the performance analysis of the Membrane Distillation (MD) process has been recently raised by several researchers. A number of studies have focused on the study of this phenomenon at a macroscopic scale looking at average values of temperature and fluxes [1-2], but none of them has presently investigated the spatial distribution of temperatures on the membrane surface, which could be a fundamental information for the choice of the best geometrical features of a spacer. Some CFD works have been presented in the literature [3] aiming at the local thermo-fluid dynamics characterisation of spacer filled channels, but no validation of model predictions with experimental information has been presented yet. In the present work a novel experimental technique, based on the use of Thermo-chromic Liquid Crystals (TLCs), has been developed and used for the investigation of temperature distribution inside a spacer-filled MD channel