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Vacuum drying is the mass transfer operation in which the moisture present in a substance, usually a wet solid, is removed by means of creating a vacuum. In chemical processing industries like food processing , pharmacology, agriculture, and textiles, drying is an essential unit operation to remove moisture. [ 1 ]
Vacuum activities (or vacuum behaviours) are innate fixed action patterns (FAPs) of animal behaviour that are performed in the absence of a sign stimulus (releaser [broken anchor]) that normally elicit them. [1] This type of abnormal behaviour shows that a key stimulus is not always needed to produce an activity. [2]
Dielectric drying (radiofrequency or microwaves being absorbed inside the material) is the focus of intense research nowadays. It may be used to assist air drying or vacuum drying. Researchers have found that microwave finish drying speeds up the otherwise very low drying rate at the end of the classical drying methods.
Many salts and solids can be dried using heat, or under vacuum. Desiccators can also be used to store reagents in dry conditions. Common desiccants include phosphorus pentoxide and silica gel. Chemists may also require dry glassware for sensitive reactions. This can be achieved by drying glassware in an oven, by flame, or under vacuum.
They are equivalent to Abderhalden's drying pistol in some ways, but vacuum ovens typically can accommodate large samples. A characteristic operation for a vacuum oven is the activation or regeneration of molecular sieves. [1] [2] Vacuum furnaces are related devices that operate at much higher temperatures and much lower pressures.
Vacuum pump and bell jar for vacuum experiments, used in science education during the early 20th century, on display in the Schulhistorische Sammlung ('School Historical Museum'), Bremerhaven, Germany. A vacuum (pl.: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective vacuus (neuter vacuum) meaning "vacant ...
A vacuum desiccator (left) and desiccator (right). Silica gel with cobalt chloride indicator placed in the lower shelf is used as the desiccant.. A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry.
Vacuum systems usually consist of gauges, vapor jet and pumps, vapor traps and valves along with other extensional piping. A vessel that is operating under vacuum system may be any of these types such as processing tank, steam simulator, particle accelerator, or any other type of space that has an enclosed chamber to maintain the system in less than atmospheric gas pressure.