A vacuum chamber is an enclosed space within a rigid structure that uses a vacuum pump to remove all air and gases and creates a low pressure vacuum state. This can be helpful in the production of products that need to avoid contamination or moisture. Vacuum chambers are also useful in some types of food production.
USES OF A VACUUM CHAMBER
Vacuum chambers have various uses in very different fields. They can be used to test objects that are built for outer space. A thermal vacuum chamber can be used to actually simulate the outer space environment the outside of a spacecraft would experience.
Another common use for vacuum chambers is degassing. When two components are mixed, sometimes gas is created as a byproduct. A vacuum environment can pull these gases away, keeping the end product pure. An example of this method being used is in the mixing of resin and silicone rubbers.
They can also be used for vacuum drying. Sometimes during the production process, liquids can collect on a product. Vacuum chambers can be used to pull the moisture off, keeping the product dry. Combined with heat, this is a very effective method of drying.
Vacuum chambers are also used often in the process of freeze drying food. Food is flash frozen (frozen quickly), then placed in a vacuum chamber where the moisture sublimates (goes directly from solid to gas) and is removed. The end result is the food being completely devoid of any water.
MATERIALS OF VACUUM CHAMBERS
Vacuum chambers need to be made of a rigid material, to resist the pressure differences created by the vacuum. They also need to avoid other pitfalls, such as corrosion, absorption of moisture or trace gases, and magnetic interference.
Most vacuum chambers are made of aluminum, as it can avoid most of these problems. It’s strong enough to withstand low to medium vacuum environments. It’s non-magnetic, which means it won’t interfere with attempts to control the magnetic field inside the chamber from the outside. It’s also good because it absorbs very little moisture and trace gases.
Some other common materials for low to medium vacuum chambers are:
- High-density ceramic
- Glass acrylic
Low to medium vacuum chambers can generally use rubber o-rings to seal their ports effectively.
For high and ultra-high vacuum chambers (having pressures lower than 10-13 atmosphere) stainless steel is often used. It can handle more extreme pressures that other materials can’t, and can be welded, making the seals stronger. It also has the properties of low magnetic interference and resistance to erosion and the absorption of moisture/gases.
High and ultra high pressure vacuum chambers generally need steel bolts to seal their ports because of the increased pressure.
To learn how to build your own, go here.
Good luck and stay prepared!