Gas purification techniques

Ionization

The air or the gas flow are conducted by an engine chamber, and by means of magnets to very strong electric flux (several dozens of kV submitted, 20 - 30 kV). As a result of the acting electric discharge reaction, the gas flow arrive in a situation which known state as `cold plasma'. In a cold plasma the gas molecules are present under form of ions, free electrons, radicals and other eye-reactive species. However no considerable temperature increase appears.

The highly reactive components in cold plasma ensure a degration and (partial) oxidation of present pollution. The most active species in this process are N, O and OH radicals. These are formed from nitrogen (N₂), oxygen (O₂) and water (H₂O).
If the gas flow is sent directly into plasma engine, itself will behave like an electrostatic precipitator with a substance removal efficiency of > 90 %. To keep the engine clean one must install a self cleaning system The cleaning can happen by vibration, press air or water. At dust-free air flows this cleaning system is not necessary. At direct treatment disposal of organic substances is possible. In case of injection of an ionized air flow one gets mainly modification of the fragrance molecules and to a lesser degree a disposal of organic freight.

After the actual ionization step the air flow can be still conducted concerning a catalyst. These work on room temperature and ensure a disposal of present ozone and ensure a further oxidation of the components to remove.
The advantages of ionization are:

• Compact system

• Peaceable both in- and outside

• On- and disconnection to need (small boot time)

• Relatively simple management

• Little sensitively for variation in the gas flow

• Gave the ionization process at low temperature

• Low energy usage in comparison with after burners (for gas flow
  with low energy-content)

• At functioning in bypass little sensitively to substance

The disadvantages are:

• A preceding test has been designated examine if technique is
  arranged for specific emission problems.

• Are as directly only suitable for fox disposal on the gas flow can
  be applied.

• Risk on electromagnetic radiation. This risk has been limited if the housing is carried out in metal.

Ionization is mainly applied in the following sectors:

• Sewage water cleaning (feeding -, chemical and leather industry)

• Sludge compostering

• Tobacco industry

• Feeding industry

• Fish food industry

• Animal food industry

• Slaughterhouses

• Grain - and Soya processing

• Potato processing (chip production)

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