Activated Carbon Filter
The activated carbon filter can remove gas and odor. This is the physical
process of binding gas molecules to a large surface or pores of an adsorbent
medium. Activated carbon is the most common media used for adsorption
and is produced by heating carbonaceous substances (containing carbon
and derived from organic substances such as bituminous coal, wood or
coconut shell) to form a carbonized char, then activating (oxidizing) with
gases such as steam and carbon dioxide to form pores and creating a highly
porous adsorbent material. The effectiveness of odor removing media is
related to the amount and type of gasses present in the air, the quantity, type
and depth of the adsorbent material and the velocity of the air traveling
through the media.
The location of the odor adsorbing media relative to the particle filtration
media is also important. If the odor adsorbing media is placed first, then
particles in the air will cover the porous structure of the odor adsorbing
media and reduce its effectiveness at trapping odors. By placing the HEPA
or electronic cell first, particles in the air are captured before the air reaches
the odor adsorbing media and allows the porous structure of the odor
adsorbing media to have maximum effectiveness at capturing gasses. Room
conditions such as air temperature and humidity also effect the capacity of
adsorbents to remove odors.
PART I GENERAL DESCRIPTION ON AIR CLEANING
1-6
Gamma
Rays
Vacuum UV
UV-C
UV-B
UV-A
X-ray
UV
Visible
Infrared
254nm
100nm
100nm
400nm
200nm
300nm
280nm 315nm
400nm
Ultraviolet (UV) Light
UV light is not visible to the human eye. It refers to the part of the wavelength spectrum below visible violet light and
above x-rays and gamma rays. All light is a form of electromagnetic radiation. The distinguishing aspect of UV light is
the wavelength which is longer than x-rays but shorter than visible light. It is named because the spectrum consists of
refrangible electromagnetic waves with frequencies higher than those that humans identify as the color violet. UV light
is typically found as part of the radiation received by the Earth from the Sun. Most humans are aware of the effects of
UV through the painful condition of sunburn. The UV spectrum has many other effects, including both beneficial and
damaging changes to human health. This technology is commonly used in a variety of healthcare and water quality
applications where the control of microorganisms is desired.
UV light possesses just the right amount of energy to break organic molecular bonds. As micro-organisms pass by the
UV rays radiated from the ultraviolet lamp, this bond breakage translates into cellular or genetic damage for
microorganisms, such as germs, viruses, bacteria, fungi (like molds), etc. This results in the destruction of the
microorganisms. Many of the air purifiers use UV lamps to kill microorganisms and activate the photo catalyst filter
around it.
Fig. 1.2-7 Ultraviolet photons harm the DNA
molecules of living organisms in different ways.
Fig. 1.2-6 The electromagnetic spectrum of ultraviolet
light can be subdivided in a number of ways.
Before
After
Incoming
UV photon
ENGLISH
Fig. 1.2-5 Activated carbon
pellets and close-up of its pores.
Summary of Contents for R200T
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