Scale up and performance test of the rotary vacuum dryer type batch for drying oyster mushrooms

Abstract

Rotary Vacuum Dryer Type Batch (RVDTB) is designed to reduce the moisture content of oyster mushrooms from ± 92% to ± 10%, at 60 °C with vacuum pressure 76 cm Hg and 8 hours drying time by capacity of 2 kg/process. Grinded dry oyster mushrooms produce flour used as a raw material due to its flexibility. This is in accordance with the Indonesian National Standard (SNI), therefore, there is a need to increase the dimensions (scale-up) of RVDTB capacity. The study aims to scale up and to test the RVDTB performance by increasing the drying capacity and suction power of the water jet pump. The methodology was used to redesign the RVDTB scale up, manufacture component, assemble, and test performance. The redesigning results shows on 36 cm diamater of cylindrical drying chamber with a length of 50 cm, and 2 HP suction pump power with the flight sets horizontally on 30°. The performance test results before and after the RVDTB scale-up were a) capacity of 2 kg and 3 kg, b) drying rate of 0.227 kg/hour, and 0.250 kg/hour, c) efficiency of 6.74 % and 7.42 %.