A vacuum drying oven is used for drying under vacuum condition, specially designed for drying heat sensitive material, and substances that are easily decomposed and oxidized. It can be used in a great variety of fields and has a relatively simple operating procedures. It has been favored by many industries for its ability to dry some complex materials rapidly. Some people may wonder how a vacuum drying oven work. Let’s talk it in the following part.
How does a Vacuum Drying Oven Work?
It is known that a vacuum drying oven is a kind of vacuum drying device under negative pressure. It makes use of a vacuum pump for pumping and dehumidification. A vacuum pump can create a vacuum condition inside the working chamber so that the boiling point of water can be lowered, accelerating the drying process.
Its working procedures are relatively complicated, mainly as follows:
- Sample placement: Put materials that need dry on the trays inside the drying oven and push them into the drying oven.
- Close the door: Gently close the door to avoid large vibration of the oven. With bolts on the door of the oven, make sure that the door is tightly bound to the silicone seal strip when it is closed.
- Switch on the vacuum: Connect the vacuum pump with the vacuum valve, successively open the vacuum pump and vacuum valve, and vacuumize.
- Heating: Turn on the heating switch to set the desired temperature, which should be carried out in a stable vacuum state.
- Temperature setting: Set the required temperature, but not exceed the rated temperature.
- Take out sample: Turn off the heating switch and then slowly open the discharge valve. Open the oven door and take out the sample when the vacuum degree is zero.
What’s the Difference between Hot Air Oven and Vacuum Oven?
Generally, there are two types of drying ovens, which are hot air ovens and vacuum ovens. Though both of them can be used for drying, there are still some differences between them. Firstly, they work in different ways. A hot air oven can dry products by using high temperature, while a vacuum oven works by using both high temperature and vacuum. Secondly, they have different applications. A hot air oven is suitable for materials that are not heat sensitive, such as glassware, needles and powders. But a vacuum oven can be used for rapid and efficient drying treatment of heat-sensitive, easily decomposed, easily oxidized materials and complex components. It can not only lower drying temperature, but prevent some materials from oxidizing in contact with air. You can choose one of them based on their differences and your own requirements.
Advantages of Vacuum Drying
Compared to other drying methods, the vacuum drying has many benefits. Firstly, the vacuum drying can remove moisture at a lower temperature and oxygen content, which makes it suitable for heat-sensitive as well as oxygen-sensitive materials. Secondly, the vacuum drying can improve the evaporation rate because of the reducing boiling point of water. Thirdly, it’s much safer to do drying in the vacuum place, because it’s impossible for oxide to explode when it’s heated under vacuum or inert condition. What’s more, the vacuum drying can save the drying time and obtain a higher quality dried product. That’s why people prefer to use a vacuum drying oven rather than other drying equipment in most cases.