There are some important differences between vacuum freeze-drying machines (also known as freeze-drying machines) and ordinary drying methods.

1. Working principle: The vacuum freeze dryer dries samples by combining low temperature and vacuum conditions. Firstly, the sample is frozen to form ice crystals, and then vacuum is applied at low temperatures to directly transform the ice crystals from solid to gas, bypassing the liquid phase (i.e., ice sublimation). On the contrary, ordinary drying methods usually place the sample at room temperature and evaporate the water by providing heat.

2. Drying speed: The vacuum freeze dryer has a faster drying speed. Due to the effects of low temperature and vacuum conditions, water is removed by sublimation, thereby increasing the drying rate. In contrast, ordinary drying methods require longer time to evaporate moisture.

3. Preserve sample characteristics: Vacuum freeze-drying machines can better preserve the characteristics of the sample. Due to the drying of the sample in a frozen state, the structure and properties of the sample are maintained during the sublimation of ice crystals, reducing the impact of the drying process on the sample. However, ordinary drying methods may cause damage or changes to the sample structure.

4. Applicability: The vacuum freeze dryer is applicable to all types of samples, including biological samples, food, drugs, chemicals, etc. It can effectively dry samples with high moisture content or temperature sensitive samples. The applicability of ordinary drying methods is relatively narrow, especially for situations where sample characteristics need to be preserved.

5. Retention of active ingredients: Vacuum freeze-drying machines can better retain the active ingredients in the sample. Due to the direct transformation of water from solid to gaseous state during the freeze-drying process, without the need for liquid state, it helps to maintain the stability and activity of the active substances in the sample. Vacuum freeze-drying is an ideal choice for samples that require the retention of active ingredients, such as biological agents, drugs, etc.

6. Avoiding pollution and oxidation: Vacuum freeze-drying machines can dry in low temperature and low oxygen environments, thereby avoiding oxidation and pollution issues. During the ordinary drying process, some sensitive components in the sample may undergo oxidation reactions or be contaminated by microorganisms in the air due to contact with air. Vacuum freeze-drying reduces the occurrence of these problems by reducing the presence of oxygen and moisture.

7. Operation control: Vacuum freeze-drying machines are usually equipped with advanced control systems, which can achieve precise control of parameters such as temperature, vacuum degree, and drying time. This makes the operation more convenient and controllable, and can be adjusted according to the needs of different samples. Ordinary drying methods are usually relatively simple and easy to operate, but cannot provide similar precise control.