The effect of material volume on freeze-drying rate, green garlic with small material volume, at the initial stage of sublimation, due to the same pressure and heating of the bottom plate, this phenomenon indicates that the volume of green garlic with small material volume is much higher than that of sublimation. This phenomenon is welcome because we hope that the water in the material will be lost as much as possible during the sublimation phase. At the same time, the process of lyophilization of the green garlic with a small material volume is short, which is instructive for production. The effect of vacuum on the lyophilization rate, under different vacuum degrees, the lyophilization rate under the vacuum is slower than the lyophilization rate under 015 Torr vacuum. However, it is generally believed that the higher the pressure, the slower the freeze-drying rate. This is contrary to our conclusion that the effect of pressure on the freeze-drying rate is driven by two opposite factors: (1) The pressure is high, and the thermal conductivity of the dry layer is correspondingly increased, and the surface convection effect is also increased, so that the sublimation water vapor is fast, that is, the lyophilization rate is large. (2) The pressure difference is large, which helps the water vapor to overflow. The smaller the pressure difference, the slower the overflow and the smaller the freeze-drying rate. That is, the smaller the degree of vacuum, the larger the pressure difference and the faster the water vapor overflows. Using the interaction of these two opposite factors, we adopt the method of pressure-adjusting and sublimation drying, that is, increasing the pressure inside the tank in the first half cycle to increase the convective heat transfer of the gas and the heat conduction of the dry layer. In the latter half of the tank, the pressure in the tank is rapidly reduced and sublimated. A large pressure difference is formed between the interface and the outer surface, and the water vapor quickly overflows, thereby increasing the rate of the freeze-dried product. Ceramic Smoking Set,Custom Ceramic Cigarette Holder,Ceramic Smoking Holder,Custom Ceramic Smoking Appliance Yixing Xiangyang Jiujiu Chinaware Industry Co., Ltd. , https://www.xyjjceramic.com