Discussion on energy saving operation of pilot Freeze Dryer from material shape and concentration
The pilot Freeze Dryer has been widely used in food, fruit and vegetable, medical and pharmaceutical, chemical, biological products and other fields because it retains the original composition of the material, has a long shelf life, and is easy to transport. The energy-saving operation of the pilot Freeze Dryer is discussed below from the shape processing and concentration adjustment of the material:
1. For liquid raw materials, if there are more colloidal substances, when the concentration is higher, appropriately reducing the concentration of the materials will help to increase the freeze-drying rate. However, the material concentration should not be too low, otherwise the energy consumption will be increased due to too much moisture removed, and the water vapor diffusion pores may be blocked and the freezing rate may be lowered. If the liquid raw material has a high water content, such as a water content of more than 80%, it should be concentrated as much as possible before lyophilization to increase the drying rate.
2. For solid materials, if there is no excessive shape requirement, the heat transfer mass transfer area can be increased by cutting treatment, thereby speeding up the freeze-drying rate and reducing the freeze-drying time; if the shape of the material is high, cutting is not allowed. Puncture treatment is adopted to facilitate the escape of water vapor inside the material, and the lyophilization rate is enhanced by strengthening the mass transfer process.