The performance indicators pursued by the lab freeze dryer are small size, light weight, multiple functions, stable performance, and high accuracy of the test system. It is best to have one machine with multiple functions, which can adapt to the freeze-drying experiment of a variety of materials. The main classification methods of lab freeze dryer types are:
1. From the structural point of view
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 of the experimental freeze dryers are of the bell jar type, with simple structure and low cost. Most freeze-drying chambers use transparent organic glass cover, which is convenient for observing the freeze-drying situation of materials.
In-situ freeze-drying machine: the freeze-drying chamber and the cold trap are two independent chambers. The shelf in the freeze-drying chamber has a refrigeration function. After the material is placed in the freeze-drying chamber, the pre-freezing and drying process of the material does not require manual operation . The production process of this type of freeze dryer is complicated and the manufacturing cost is high. However, the in-situ freeze dryer is the development direction of the freeze dryer. It is an ideal choice for exploring the freeze drying process. It is especially suitable for medicine, biological products and other special products. Freeze-dried.
A, ordinary type b, multi-manifold type c, gland type
Ordinary shelf type: The materials are packed in bulk in the material tray, which is suitable for freeze-drying food, Chinese herbal medicine and powder materials.
Type with capping device: suitable for drying cillin bottled materials. When preparing for lyophilization, the materials are divided into cillin bottles as needed. After the cap is floated, the cap is frozen and dried. After drying, the capping mechanism is operated to tighten the cap. , Can avoid secondary pollution, re-absorb moisture, easy to store for a long time.
Multi-manifold type: Connect the flask outside the drying chamber to dry the material spin-frozen on the inner wall of the bottle. At this time, the flask is connected to the manifold outside the drying box as a container. The material in the flask is heated at room temperature and passes through the multi-manifold. The tube switch device can be removed or installed at any time as needed without stopping the machine.
Type with pre-freezing function: During the material pre-freezing process, the cold trap is used as the pre-freezing cavity to pre-freeze the material. In the drying process, the cold trap is a water trap to capture the overflowing moisture of the material. The freeze-drying machine with pre-freezing function, the pre-freezing and drying of materials in the freeze-drying process are completed on the freeze-drying machine, the use of the freeze-drying machine is efficient, and the cost of the low-temperature refrigerator is saved.