Freeze dryer machine
The basic idea of freeze dryer machine is to completely remove water from some material, such as food, while leaving the basic structure and composition of the material intact. The fundamental principle in freeze dryer machine for sale is sublimation, the shift from a solid directly into a gas. Just like evaporation, sublimation occurs when a molecule gains enough energy to break free from the molecules around it. Water will sublime from a solid ice to a gas when the molecules have enough energy to break free but the conditions aren't right for a liquid to form.
Freeze dryer machines are divided into cheap pilot-scale laboratory, low-cost home use type and production freeze dryers. And there are several freeze dryer machine manufacturers in China to produce large sized inexpensive machines. A typical freeze dryer machine consists of a chamber with several shelves attached to heating units, a freezing coil connected to a refrigerator compressor, a vacuum pump and control system. With most freeze dryer machine, you place the material to be preserved onto the shelves or separate freezer room when it is still unfrozen. When you seal the chamber and begin the process, the freeze dryer machine runs the compressors to lower the temperature. The material is frozen solid, which separates the water from everything around it, on a molecular level, even though the water is still present. Next, the freeze dryer machine turns on the vacuum pump to force air out of the chamber. The heating units apply a small amount of heat to the shelves, causing the ice to change phase. Since the pressure is so low, the ice turns directly into water vapor. The water vapor flows out of the freeze-drying chamber, past the freezing coil. The water vapor condenses onto the freezing coil in solid ice form, in the same way water condenses as frost on a cold day. This continues for many hours while the material gradually dries out. The process takes so long because overheating the material can significantly change the composition and structure. Additionally, accelerating the sublimation process could produce more water vapor in a period then the pumping system can remove from the chamber. This could rehydrate the material somewhat, degrading its quality.
Once the material is dried sufficiently in the freezer machine, it's sealed in a moisture-free package, often with an oxygen-absorbing material. If the package is secure, the material can sit on a shelf for years and years without degrading, until it's restored to its original form with a bit of water. If operating freeze dryer machine correctly, the material will go through the entire process almost completely unscathed!