Precipitation voltage

Example 13.3 An electrostatic precipitator sampler consists of a 0.020-indiameter wire placed along the axis of a 1.5-in-diameter tube. What is the maximum field strength (assuming negligible space charge) at the outer edge of the tube when the precipitator voltage is 20 kV ... 

Example 13.4 Determine the field strength for the sampler in Example 13.3 considering ionic space charge. The precipitator voltage is 20 kV. Assume 20°C, standard pressure, f = 0.6. Use Z = 2.2 cm2/(Vs ). 

Opera.tingPrinciples. No collection will occur in a precipitator, and no current will flow in the secondary circuit, until gas ionization starts around the discharge electrode. This process is known as corona formation. The starting voltage for corona in air in a tube precipitator is given as... 

Power Supply Electrical precipitators are generally energized by rectified alternating current of commercial frequency. The voltage is stepped up to the required value by means of a transformer and then... 

Alumina produced by the Bayer process is precipitated and then calcined [Krawczyk, Ceramic Forum International, 67(7-8), 342-8 (1990)]. Aggregates are typically 20 to 70 [Lm, and have to be reduced. The standard product is typically made in continuous dry ball or vibra-toiy mills to give a product d o size of 3-7 [Lm, 98 percent finer than 45 [Lm. The mills are lined with wear-resistant alumina blocks, and balls or cylinders are used with an alumina content of 80-92 percent. The products containing up to 96 percent AI9O3 are used for bricks, kiln furniture, grinding balls and liners, high voltage insulators, catalyst carriers, etc. 

RooBng plants (asphalt saturators) Felt or paper saturators spray section, asphalt tank, wet looper Crushed rock or other minerals handling Asphalt vapors and particulates (liquid) Particulates (dust) Exhaust system with high inlet velocity at hoods (3658 m/s [>200 ft/min]) with either scrubbers, baghouses, or two-stage low-voltage electrostatic precipitators Local exhaust system, cyclone or multiple cyclones... 

---