Instruction
Vacuum drying, also known as desiccation, is a process that removes moisture or small amount of liquid from substance by reducing pressure with aid of vacuum pump to lower boiling point (bp) of liquid and accelerate evaporation rate. It is especially suitable for drying and keeping materials that are heat-sensitive, easily decomposed, oxidized, and need dustless storage. Vacuum drying is generally used with vacuum desiccator or vacuum cabinet, which is an enclosed, sealed container and can bear certain vacuum without deformation.
In addition to drying and storage, another applications with vacuum desiccator and cabinet is degassing, also known as degasification, which is a method for removing dissolved gases from liquids. Degassing works when pressure surrounded the substance is reduced and then dissolved gas escapes from liquid due to pressure difference, achieving a result of bubbles elimination.
The pump selection varies depending on used solution (water or chemicals) and size of desiccator or cabinet. The flow rate of pump is directly proportional to capacity of vacuum container; moreover, a pump with higher (deeper) vacuum should be chosen while viscous sample carries out.
Applications
- Cosmetic industry, such as degassing of gel, lotion, etc.
- Electronics industry, such as storage of electric and electronics components
- Environmental Analysis, such as drying cycle in suspended solid test
