E-6
ENGLISH
PART I GENERAL DESCRIPTION ON AIR CLEANING
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.
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.
Ultraviolet photons harm the DNA molecules
of living organisms in different ways.
The electromagnetic spectrum of ultraviolet light can be
subdivided in a number of ways.
Before
After
Incoming
UV photon
Activated carbon pellets and
close-up of its pores.
