Effect of Hot Air Reservoir and Insulator Tray in the Development of Vacuum Freeze Drying

The Objective of this work is to know the effect of inserting hot air from reservoir to the process of vacuum freeze drying. Tentacle of jelly fish as a sample with constant weight of 50 g and placed at insulator and teflon container which isolated. The samples were freezed and dried with condition at experiment varying between inserting and without inserting hot air at temperature of 27 C and also heating from heat loss condenser. The result of experiment shows that while inserting hot air into vacuum freeze drying makes the pressure to rise until the pressure reaches 40 mbar. This phenomenon makes the material evaporation and this event cannot be done in vacuum freeze drying. When without hot air reservoir the pressure can reach 3.5 mbar and the subimation can be done in this process. Vacuum freeze drying process without hot air reservoir needs time 12.5 hours and for vacuum freeze drying with hot air reservoir needs time 11 hour to drying 50 g of jelly fish tentacle. For process with insulator tray the material can be done in 22,7 hour with internal freezing. From this experiment, it can be concluded that for vacuum freeze drying with inserting hot air needs more ability of vacuum pump specially in flowrate and ultimate vacuum to keep the chamber pressure below the triple point condition.