LAUSR

Abstract This research evaluated the performance of a novel vacuum dryer using the steam ejector. The performance observed was related to the energy efficiency and drying period of the vacuum dryer by comparing the dryer that operated near atmospheric pressure. The drying process applied to solid materials e.g., cocoa and coffee beans where their moisture ranged from 28 to 35%. The drying process experiment was carried out at a temperature ranging from 50 to 60 0C, while the vacuum pressure was 82 kPa and 90 kPa. This experimental study showed that the energy efficiency of using the vacuum dryer was 11 to 12% lower and the drying time tended to be 1 to 2 hours faster than using the dryer with near atmospheric pressure. The energy consumption at a vacuum drying condition revealed a potential energy reduction by more than 10% using the novel drier with steam ejector.