High speed rotation

There have been many variations in the design of electric arc reactors but only three have been commercialized. The most important is the installation at Hbls. The other commercial arc processes were those of Du Pont (3) (a high speed rotating arc) and a Romanian process that produced both ethylene and acetylene. The Hbls process and the Romanian process (at Borzesti, Romania) are still operating, but the Du Pont process has been shut down since 1969. 

Swearingen, J. S. and Mafi, S., 1969. Experimental Investigation of Vibrations in High Speed Rotating Maehinery, ASME Paper No. 69 VIBR-58. 

Because of the minimal contact between the stationary ring and the rotor, these seals, when properly designed, are ideal for high-speed rotating machinery. 

A total analysis of high-speed rotating equipment requires a eomplex blend of performanee and vibration data. The trend toward total analysis is growing with the problems of an energy shortage and the need for maximum plant utilization. Performanee analysis is essential in the effieient utilization of turbomaehinery and, when eoupled with vibration analysis, is an unbeatable tool as a total diagnostie system. 

Boyce, M.P., Morgan, E., and White, G., Simulation of Rotor Dynamics of High-Speed Rotating Machinery, Proceedings of the First International Conference in Centrifugal Compressor Technology, Madras, India, 1978, pp. 6-32. 

Process equipment may be responsible for other sources of air movement in the room. For example, high-speed rotating machines such as pulverizers, high-speed belt material transfer systems, falling granular materials, and compressed air escaping from pneumatic tools all produce air currents. 

Fig. 8(a) shows the design of a rotating hemisphere electrode used in the author s laboratory [14], It is composed of a hemisphere electrode, an arcylic support rod, and a tappered brass holder to be attached to a high speed rotator [Fig. 8(b) ]. The electrode is machined into the form of a metal screw with a hemispherical head, and is threaded into the inert acrylic support rod of a larger radius. The design has the advantages that... 

The pumping action is due to a high-speed rotating surface that transfers momentum to the gas molecules (see Fig. 1.16). 

Whitley, S. Reviews of Modern Physics 56 (1984) 41, 67. Review of the gas centrifuges until 1962. Part I Principles of separation physics. Part II Principles of high-speed rotation. 

Noncontact Seals Noncontact seals are used extensively in gas service in high speed rotating equipment. These seals have good mechanical reliability and minimum impact on the rotor dynamics of the system. They are not positive sealing. There are two types of non-contact seals (1) labyrinth seals and (2) ring seals. 

Impeller Problems The high-speed rotation of the impeller of a centrifngal compressor imparts the vital aerodynamic velocity to the flow within the gas path. The buffeting effects of the gas flow can canse fatigue failures in the conventional fabricated shrouded impeller due to vibration-induced alternating stresses. These may be of the following types ... 

Foam Control. Fermentations tend to froth because metabolites have surfactant properties. Prevention commonly is by addition of antifoam agents such as oils, heavy alcohols, fatty acids, or silicones. High-speed rotating impellers destroy bubbles by direct impact and by throwing them against the wall of the vessel. 

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