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Its construction and principle of operation is simple. It consists of a titanium filament through which a high current (typically around 40 A) is passed periodically. This current causes the filament to reach the sublimation temperature of titanium, and hence the surrounding chamber walls become coated with a thin film of clean titanium.
Ion pumps; Titanium sublimation pumps; Non-evaporable getter (NEG) pumps; Cryopumps; Diffusion pumps, especially when used with a cryogenic trap designed to minimize backstreaming of pump oil into the systems. Turbo pumps and diffusion pumps rely on supersonic attack upon system molecules by the blades and high speed vapor stream, respectively.
A sublimatory [1] [2] or sublimation apparatus is equipment, commonly laboratory glassware, for purification of compounds by selective sublimation. In principle, the operation resembles purification by distillation , except that the products do not pass through a liquid phase .
Titanium tetrachloride is also used to make titanium dioxide, e.g., for use in white paint. [52] It is widely used in organic chemistry as a Lewis acid, for example in the Mukaiyama aldol condensation. [53] In the van Arkel–de Boer process, titanium tetraiodide (TiI 4) is generated in the production of high purity titanium metal. [54]
Getter pump or sorption pump In laboratory vacuum systems, the bulk NEG getter is often held in a separate vessel with its own heater, attached to the vacuum system by a valve, so that it can be replaced or renewed when saturated. [8] Ion getter pump Uses a high voltage electrode to ionize the gas molecules and drive them into the getter surface.
In thermodynamics, the enthalpy of sublimation, or heat of sublimation, is the heat required to sublimate (change from solid to gas) one mole of a substance at a given combination of temperature and pressure, usually standard temperature and pressure (STP). It is equal to the cohesive energy of the solid.
Most general pumps can increase as well as decrease the pressure of a gas; however, this category contains pumps that are usually exclusively used to decrease pressure. Wikimedia Commons has media related to Vacuum pumps .
This is the principle behind a positive displacement pump, for example the manual water pump. Inside the pump, a mechanism expands a small sealed cavity to reduce its pressure below that of the atmosphere. Because of the pressure differential, some fluid from the chamber (or the well, in our example) is pushed into the pump's small cavity.