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Absolute filter |
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| The gas flow that needs cleaning are conducted in a chamber and by so-called Hepa-filter are conducted. HEPA stand for High Efficiency Particle Air. The filter material of Hepa-filter exist from very thin glass fibers which have been grasped in paper. To obtain an as big as possible filter area, the glass fiber paper is fold up as a harmonica. This is necessary because the dense mass of glass fiber paper lets little air through . To move a sufficiently large air quantity therefore large a surface necessary. The substance lags behind on the filter, but does not penetrate. In other words it goes for a process of surface filtration. The substance layer which can deposit himself on the filter initially can influence the substance capture output favorably. However after some time the pressure drop concerning the filter becomes too large and these must be replaced. Hepa-filters are only seldom cleaned, because the cleaning can create damage and leaks of the filter. |
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Figure: HEPA-filter At the most attentive implementation forms the filter entities
are rectangular or cylinder of form. Absolute filters have a very high substance disposal output (up to more
than 99.99% for PM0,01 and more than 99.9999% for PM0,1.
The disadvantages of the filter are:
Absolute filters are suitable for applications where a far-reaching
disposal of sub micron substance particles is required or where one has
to do with toxic or dangerous substance particles. They can be used as
a last step of a substance disposal system, after
for example electrostatic or cloth filter. Absolute filters are used a
lot for
inside air filtration and at places where a high air quality is necessary,
for example in operation chambers of hospitals or in production spaces in
pharmaceutical, photographic and the electronics sector. Click here for more information for dust purification technology For more books and reading information see our website: Air treatment books overview
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