Investigation on the effect of condensing moisture before heating air on the performance of a batch tray dryer: Application to the drying of vanilla

This article presents the results of an investigation of the effect of pre-dehumidifying the drying air before it is heated and supplied into a batch tray dryer. Dehumidification is achieved through moisture condensation as the air flowing through a coil is cooled by chilled water from a cold source. As an example, this process is applied to the drying of vanilla and is based on a numerical method already validated by former results. Then, it is established through comparisons with a conventional batch tray dryer model that pre-dehumidification significantly reduces drying time. Furthermore, preheating air by an intermediate heating source reduces total energy consumption of the primary heating system to a level depending on the preset drying temperature. As regards batch tray dryer design and optimization purposes, these results open up particularly interesting heating and cooling sources utilization prospects.