Freeze Dryer Principle And Structure Diagram
Freeze-drying technology, also known as vacuum freeze-drying technology, originated in the 1820s and entered the 21st century. Freeze-drying technology has been widely used in fields other than medicine, biological products, food, blood products, and active substances.
The working principle of the freeze dryer is a technology that uses the principle of sublimation for drying, which is to quickly freeze the dried material at low temperature, and then in an appropriate vacuum environment, the frozen water molecules are directly sublimated into water vapor to escape. process. The product obtained by lyophilization is called a lyophilizer, and the process is called lyophilization.
The substance is always at a low temperature (frozen state) before drying, and the ice crystals are evenly distributed in the substance. The sublimation process will not cause condensation due to dehydration, and avoid side effects such as foaming and oxidation caused by water vapor. The dry substance is porous in the form of a dry sponge, the volume is basically unchanged, and it is easily soluble in water and returns to its original state. Physicochemical and biological denaturation of dry substances is prevented to the greatest extent possible.
Structure diagram of freeze dryer
The freeze dryer is composed of a refrigeration system, a vacuum system, a heating system, and an electrical instrument control system. The main components are drying box, condenser, refrigeration unit, vacuum pump, heating/cooling device, etc.
The refrigeration system is the most important part of the freeze dryer and is called the "heart of the freeze dryer". Its refrigeration system is mainly composed of the following components: compressor, refrigerant, oil separator, water condenser, filter drier, intercooler, sight glass, solenoid valve, hand valve (top cover valve), expansion valve, evaporation (plate exchanger, rear box condensing coil), vapor-liquid separator, return air filter, pressure gauge, pressure control relay, CPCE (energy conditioner), safety valve, refrigeration pipeline, etc.
