Laboratory freeze dryer structure

Laboratory freeze dryers can be divided into the bell-jar type and in-situ type according to their structure. The structural design of the laboratory freeze dryer is that the refrigeration unit is arranged in the casing; the cold trap is arranged on the upper part of the casing; the vacuum pump is connected to the cold trap through a vacuum pipeline; the refrigeration unit has a compressor, a heat exchanger, an expansion valve, and an evaporator; it also includes The material placement device is installed above the cold trap and on the shell, and communicated with the upper end of the cold trap; the evaporator is an evaporation coil, which is arranged in the cold trap. The evaporator is changed to an evaporative coil, and it is set in a cold trap, and the cooling speed is fast.

1. Bell jar type freeze dryer: The freeze-drying chamber and the cold trap are separate upper and lower structures, and the freeze-drying chamber has no pre-freezing function. This type of freeze dryer requires manual operation when the material is transferred to the drying process after pre-freezing. Most laboratory freeze dryers are of the bell jar type, which has a simple structure and low cost. Most of the freeze-drying rooms use a transparent plexiglass cover, which is convenient for observing the freeze-drying of materials.

2. In-situ small freeze-drying machine: The shelf in the freeze-drying room has a refrigeration function. After the material is placed in the freeze-drying room, the pre-freezing and drying process of the material does not require manual operation. The production process of this type of freeze-drying machine is complicated and the manufacturing cost is high, but the in-situ type is the development direction of the freeze-drying machine, and it is an ideal choice for the exploration of the freeze-drying process.