Abstract:In order to solve the problem of long drying time and high breakage rate of Poria cocos cubes during industrial drying process, the infrared drying technology of carbon fibers was combined with the vacuum pulsating drying technology, and a pulsed vacuum drying equipment was designed based on characteristic carbon fibers infrared plate. The pilot-scale drying equipment consisted of drying chamber, vacuum system, single-layer drying unit and control system. For convenience of analysis, the actual vacuum pulsed process was divided into four stages: vacuum stage, vacuum holding stage, breaking stage and atmospheric pressure holding stage. The touch screen was connected with the slave controllers by RS232/485 to form a network, and communicated with each other through the MODBUS protocol. Based on the monitoring of vacuum degree in drying chamber, the continuous conversion from vacuum to atmospheric pressure in drying chamber was realized by time sequence control. Based on the monitoring of the temperature of carbon fiber infrared board and the feedback of the drying temperature, the drying temperature can be effectively controlled. Poria cocos cubes with size of 12mm×12mm×12mm was used as experimental material to verify the results. The results showed that the design and control scheme of the drying equipment were reliable, and the continuous pulsation of vacuumatmospheric pressure can be realized, and the material can be dried effectively. The shortest drying time was about 480min when the vacuum duration time and atmospheric pressure duration time were 5min and 4min, respectively. Compared with continuous hot air drying, the breakage rate of pulsed vacuum drying was obviously reduced. The drying equipments and results can be applied to the drying of Poria cocos cubes, which can provide theoretical basis for the combined application of infrared drying technology and pulsed vacuum drying technology.