Vacuum systems

For the vacuum device, see cryopump In vacuum applications a cold trap is a device that condenses a vapor into either a liquid or a solid. Two common examples of this process occur in cryopump systems, which generate hard vacua by condensing the major constituents of an ambient atmosphere (nitrogen, oxygen, carbon dioxide and water) into their ices. Vacuum pump that condenses the gas or vapour on a cold surface. ... Vacuum pump that condenses the gas or vapour on a cold surface. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ... This article focuses on water as it is experienced in everyday life. ...

The second most common use of this term is in the application of cooled surfaces or baffles to prevent oil vapours from flowing from a pump and into a chamber. In such a case, a baffle or a section of pipe containing a number of cooled vanes, will be attached to the inlet of an existing pumping system. By cooling the baffle, either with a cryogen such as liquid nitrogen, or by use of an electrically driven Peltier element, oil vapour molecules that strike the baffle vanes will condense and thus be removed from the pumped cavity.

Pumps that use oil either as their working fluid (diffusion pumps), or as their lubricant (mechanical rotary pumps), are often the sources of contamination in vacuum systems. Placing a cold trap at the mouth of such a pump greatly lowers the risk that oil vapours will backstream into the cavity.

Astronomy

In astronomy, a cold trap is a close to the surface layer of the atmosphere that is substantially colder than both the deeper and higher layers. It is called a trap because it keeps ascending gases with high melting points in by freezing them to a solid which then drops back to the planet surface. The most important gas to be kept in that way, on the Earth, is water vapor, which without the presence of a cold trap in the atmosphere (which for the earth resides at about 20 kilometers height) would gradually escape or dissociate into space, making life impossible. Radio telescopes are among many different tools used by astronomers Astronomy (Greek: αστρονομία = άστρον + νόμος, astronomia = astron + nomos, literally, law of the stars) is the science of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earths atmosphere (such as auroras and cosmic background radiation). ... Layers of Atmosphere (NOAA) Air redirects here. ... Dissociation in chemistry and biochemistry is a general process in which complexes, molecules, or salts separate or split into smaller molecules, ions, or radicals, usually in a reversible manner. ...