Electric charge atmospheric dust

A device used to remove fly-ash from boiler exit-gases in order to reduce the atmospheric pollution load. It places an electric charge on the dust particle and removes the particle onto a collecting plate. 

Explosivity Fine dust dispersed in air in sufficient concentrations and in the presence of an ignition source, is a potential dust explosion hazard. Minimum concentration for explosion is 0.25 oz. ft The recommended fire extinguishing media is water spray, dry chemical, alcohol foam, or carbon dioxide. Acetaminophen is capable of generating a static electrical charge. Processes involving dumping of acetaminophen into flammable liquid, inert atmosphere in the vessels, or temperatures of flammable liquid should be maintained below its flashpoint. 

Dirt, dust, fibres, grit and hairs are ever-present in a non-filtered atmosphere and vary from submicrometre, invisible particles to visible, clearly definable units. Particles of below 50 pm are not easily seen by persons with normal eyes. Contamination from the environment is also dependent on the prevailing atmospheric conditions and any electrical charges carried by the particles and the materials which may become contaminated. Such charges are usually increased by dry, low-RH conditions and lessen as humidity rises. 

Figure 1.8 shows an example of an indoor aerosol of solid particles (dust aerosol). Aerosols are not thermodynamically stable but, as a practical matter, some aerosols occur that may be stable for days to a few weeks, such as in the atmosphere. Most metastable aerosols that will be encountered in practice contain extremely smaU particle or droplet sizes, and the particles or droplets may carry significant electric charges, such as the charged particles or droplets in thunderclouds. 

Electrical forces may also act on dust particles before they come into contact with the surface (see Section 16) i.e., it is possible in principle to make coatings that are dust repellent, principally with reference to atmospheric dust. An example may be found in alkyd-styrene structural paints with a low binder content [221]. A similar result can be achieved by treatment of various particles with a 1% aqueous solution of the cationic substance Arquad 18, which, according to data furnished by Armour (USA), prevents dust accumulation on the articles for a period of several months. In this particular case, the dust-retention tendency is reduced by removal of the electric charges from plastic articles by a process that is analogous to the action of antistatic agents [222]. Also available are dust-collecting paints and enamels, which create their own electric field. 

Local atmospheric conditions such as thunderstorms and static charge build up are important considerations for electrical safety in your system. Static charges can build up due to windblown dust, snow, water, pollen and many other causes. 

A glass cleaned in this way shows static electrification. This charge must be eliminated by a treatment in ionized clean air to prevent the attraction of dust particles from the atmosphere which adhere very strongly because of the electric forces. 

Explosions and fire may arise from electrical shorting, leaking fuel pipes, dust accumulation (spontaneous combustion) and from hydrogen generation during battery charging. The truck itself can be the source of ignition if operated in flammable atmospheres... 

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