ahmadvand.org: راهنماي انتخاب وسايل كنترل آلودگي هوا

راهنماي انتخاب وسايل كنترل آلودگي هوا
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مدیرسایت در 2016-01-22

Air pollution control can be generally described as a “separation”
technology. The pollutants, whether they are gaseous, aerosol, or solid
particulate, are Separated from a carrier gas, which is usually air.

AIR POLLUTION CONTROL0d0a EQUIPMENT SELECTION GUIDE0d0a. Air pollution control
can be generally described as a  “separation” technology. The pollutants,
whether they are gaseous,  aerosol, or solid particulate, are Separated from a
carrier  gas, which is usually air. We separate these substances because, if we 
don’t, these pollutants may adversely affect our health and that of the 
environment. Of primary importance is the effect of the pollutants on  our
respiratory system, where the impact is most noticeable. Gaseous  pollutants are
compounds that exist as a gas at normal environmental  conditions. Usually,
“normal” is defined as ambient conditions. These  gases may have, just
moments before release, been in a liquid or even  solid form. For the purposes
of the air pollution device, however, the  state they are in just prior to
entering the control device is what is  most important. Aerosols are finely
divided solid or liquid particles  that are typically under 0.5 m
diameter.0d0a0d0a0d0aThey  often result from the sudden cooling 28condensation29
of a gaseous  pollutant, through partial combustion, or through a catalytic
effect in  the gas phase. In the latter condition, a pollutant in the gas phase
may  combine to form an aerosol in the presence of, for example, a metal 
co-pollutant. Acid aerosols such as SO , for example, can form in the  presence
of vanadium particulate that may be evolved through the  combustion of oil
containing vanadium compounds. Solid metals in a  furnace can sublime 28change
phase from solid directly to gaseous29 in the  heat of an incinerator, then cool
sufficiently to form a finely divided  aerosol.