Electrical precipitators electric wind

Electric Wind By virtue of the momentum transfer from gas ions moving in the electrical field to the surrounding gas molecules, a gas circiilation, known as the electric or ionic wind, is set up between the electrodes. For conditions encountered in electrical precipitators, the velocity of this circulation is on the order of 0.6 m/s. (2 ft/s). Also, as a result of this momentum transfer, the pressure at the collecting eleclrode is slightly higher than at the discharge electrode (White-head, op. cit., p. 167). 

For two-stage precipitators with close collecting-plate spacings (Fig. 17-76), the gas flow is substantially streamline, and no electric wind exists. Consequently, with reentrainment neglected, collection efficiency may be expressed as [Penny, Electr. Eng, 56, 159 (1937)]... 

A direct application to chemical process technology of the principle of electric wind is in electrostatic precipitators (Leonard et al.,1983) and electrocyclones for size separation of particles in powder technology (Nenu et al., 2009). Electrostatic precipitators applied to exhaust gas cleaning have recently been reviewed 0aworek et al., 2007). A particularly interesting development is that of a small electrocyclone with a diameter of 75 mm (Shrimpton and Crane, 2001). With this device it was shown that the separation quality of the smallest size particles with a diameter below 38 pm doubled upon application of the electric wind. Later experiments performed with submicron silica particles demonstrated that classification of such particles is possible by use of an electrical hydrocyclone (Nenu et al., 2009). 

Foremost among these are the electric fields generated by the solar wind-geomagnetic field interaction, the presence of intense particle precipitation within the auroral oval, the polar wind escape of thermal plasma, and other features resulting fi om the auroral disturbance of the neutral atmosphere. 

Wind can affect the structural integrity of light surfaces, but can also be the root cause of dangerous effects other than missiles and rain as discussed in the appropriate sections. The pressure differential could affect the ventilation system dust and sand carried by the wind could damage exposed surfaces and prevent the functioning of components and equipment. Salt water precipitation could jeopardize the functionality of electrical equipment. 

Joerissen et al. (2004) made a detailed technical and economic analysis of the potential of vanadium redox flow batteries in various low-power energy systems in which the primary source of electrical energy would be solar batteries and wind power generators, both highly variable. The authors noted as a drawback in long-term operation of the battery at elevated temperatures that part of the pentavalent vanadium may precipitate as insoluble oxide (V2O5). 

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