The 1950s saw the development of vacuum technology at a rapid speed; nowadays, researches and various industries utilize it. In comparison to other available mechanisms in the market today, technical procedures that could be done using vacuum processes is relatively larger and corresponds to more areas of application. While this fact remains irrefutable, only a discussion of the pumping process shall be discussed in this article.
A survey of the most important processes in vacuum technology and the pressure regions in which these processes are mainly carried out was done to evaluate the pumping process.
Pressure ranges (p < 1000 mbar) of physical and chemical analytical methods
Pressure ranges of industrial vacuum processes
In general, the pumping operation for these such process could be divided into two categories: dry vacuum procedures and wet vacuum procedures. These processes both demand that no significant amounts of vapor have to be pumped or those in which vapors (mostly water or organic) arise.
Dry processes primary work in narrow and limited pressure regions. Prior to the onset of the actual working process, the system is usually evacuated to a suitable characteristic pressure. For instance, this occurs in plants for evaporative coating, crystal pulling, electron-beam welding, as well as in particle accelerators, mass spectrometers, or electron microscopes.
Furthermore, there are dry processes in which degassing in vacuum is the actual technical process. These include work in induction- and arc furnaces, steel degassing plants, and plants for the manufacture of pure metals and electron tubes.
Wet processes are commonly utilized in a prescribed working environment that covers a wide pressure region. Such process is of utmost importance in drying solid materials. If work is undertaken prematurely at very low pressure, then the outer surface of the region would dry out too quickly. This would result in an impaired thermal contact and increased drying time. Processed involved in drying, impregnating, and freeze-drying plants typically fall under this category.
The production of the maximum liquid surface is important in removing water vapor from liquids or in their distillation, particularly in degassing columns, vacuum filling, resin-casting plants, and molecular distillation. In all wet processes, the provision of the necessary heat for evaporation of the moisture is also of great importance.
This information has been sourced, reviewed and adapted from materials provided by Leybold GmbH.
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