Desiccator


Desiccator
A desiccator (right) and a vacuum desiccator (left) - note the stopcock which allows a vacuum to be applied. The blue silica gel in the space below the platform is used as the desiccant.

Desiccators are sealable enclosures containing desiccants used for preserving moisture-sensitive items such as cobalt chloride paper for another use. A common use for desiccators is to protect chemicals which are hygroscopic or which react with water from humidity.

The contents of desiccators are exposed to atmospheric moisture whenever the desiccators are opened. It also requires some time to achieve a low humidity. Hence they are not appropriate for storing chemicals which react quickly or violently with atmospheric moisture such as the alkali metals. A glovebox or Schlenk-type apparatus may be more suitable for these purposes.

Desiccators are sometimes used to remove traces of water from an almost-dry sample. Where a desiccator alone is unsatisfactory, the sample may be dried at elevated temperature using Abderhalden's drying pistol.

Operation

In laboratory use, the most common desiccators are circular, and made of heavy glass. There is usually a removable platform on which the items to be stored are placed. The desiccant, usually an otherwise-inert solid such as silica gel, fills the space under the platform.

A stopcock may be included to permit the desiccator to be evacuated. Such models are usually known as vacuum desiccators. When a vacuum is to be applied, it is a common practice to criss-cross the vacuum desiccator with tape, or to place it behind a screen to minimize damage or injury caused by an implosion. To maintain a good seal, vacuum grease is usually applied to the flanges.

See also

References


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Look at other dictionaries:

  • Desiccator — Des ic*ca tor, n. 1. One who, or that which, desiccates. [1913 Webster] 2. (Chem.) A short glass jar fitted with an air tight cover, and containing some desiccating agent, as sulphuric acid, phosphorus pentoxide, or calcium chloride, above which… …   The Collaborative International Dictionary of English

  • desiccator — [des′i kāt΄ər] n. 1. an apparatus for drying foods, etc., esp. by heat 2. a chemist s device containing a water absorbing material, used to dry or store substances …   English World dictionary

  • desiccator — eksikatorius statusas T sritis chemija apibrėžtis Storasienis stiklinis indas medžiagoms lėtai džiovinti arba saugoti nuo drėgmės. atitikmenys: angl. desiccator rus. эксикатор …   Chemijos terminų aiškinamasis žodynas

  • desiccator — eksikatorius statusas T sritis fizika atitikmenys: angl. desiccator; exsiccator vok. Exsikkator, m rus. эксикатор, m pranc. exsiccateur, m …   Fizikos terminų žodynas

  • desiccator — noun see desiccate …   New Collegiate Dictionary

  • Desiccator — Exsiccator mit Silicagel Ein Exsikkator (auch: Exsiccator, von lat. exsiccare: austrocknen) ist ein chemisches Laborgerät, das hauptsächlich zur Trocknung fester chemischer Stoffe in der präparativen Chemie Verwendung findet. Bei einem Exsikkator …   Deutsch Wikipedia

  • desiccator — /des i kay teuhr/, n. 1. an apparatus for drying fruit, milk, etc. 2. Chem. a. an apparatus for absorbing the moisture present in a chemical substance. b. an airtight, usually glass container containing calcium chloride or some other drying agent …   Universalium

  • desiccator — noun A closed glass vessel containing a desiccant (such as silica gel) used in laboratories for drying materials or for keeping them dry …   Wiktionary

  • desiccator — 1. SYN: desiccant (2). 2. An apparatus, such as a glass chamber containing calcium chloride, sulfuric acid, or other drying agent, in which a material is placed for drying. vacuum d. a d. that can be evacuated. * * * des·ic· …   Medical dictionary

  • desiccator — des·ic·cator || desɪkeɪtÉ™(r) n. dryer, dehydrator, device which removes all moisture from food …   English contemporary dictionary


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