Latest Update: April 11 2007
These types of filters can be EXTREMELY Effective for removing Extremely Small Dust
and Smoke Particles from the Air.
A vast majority of these Commerical Units that are on the market today are
Crap.
Additionally, "Ionic Filters" that don't use a Fan are Very "Inefficient" in Collecting Dust Particles.
The plates on them are very small and even though they may appear to collect a lot of dust, the surface area
is small, giving a false impression of the real amount collected. Additionally they only collect dust in
there Immediate Vacinity and if there is is little or no real air flow in the room, it will do
very little to clean all the air in a room.
The Basic principal of operation is to first charge the air flow either
positive or negative, using a High Voltage Source of typically 4,000
to 5,000 Volts. Than past this air flow between sets of oppositely charged
plates.
These positive and negative plates are alternately stacked as Positives and Negatives,
about 0.2 inchs apart one on top of the other, so there is significent area for the volume of
air to flow freely and at a relativel slow speed through the spaces between.
As the air passes between these plates, all particles of matter will be
Rejected from the Like charged plates and
Attracted to the "Opposite charged plates".
One Essential feature is to have the plates deep enough to allow for the
rejection and attraction of the small particles.
The other essential is to have a Relatively Slow Air Flow across each plate.
A well designed filter will have plate with a depth of 5 inches Minimum.
With as many stacked plates at your desired width to allow for a "gentle flow"
across each one.
Pre-Filter: It is also a good idea to have a very simple screen filter, to catch "Larger
particles of "Lint" as these can clog up an electrostatic filter quickly, but
the electrostatic plates and Pre-Filter Screen, never need replacing, just a good washing from time
to time.
Now this can operate on either 110 or 220 VAC.
Especially the ones used in Pubs and Bars which are: "Very Poorly Designed"
with plates having a depth of about 3 inches.
But even Far Worse are Most of the Electrostatic Furnace Filters
with plates only about 1 inch deep.
(Voltages greater than 5,000 volts creates large amounts of Ozone, which can be harmful to a
persons health and voltages less than 4,000 volts doesn't effectively charge
the particles in the air.)
This is simular in principal to rubbing a balloon on your hair which will than
allow it to stick to a wall.
Both these design features give the particles more chance
to attach themselves to the opposite charged plate.
Unlike all the paper filters such as "Hepa" and many others:
Electrostatic filters have very little resistance to air flow.
Also contrary to most persons who believe "Hepa" is a Specific Type of filter.
It Isn't!
It is a "Trade Name" and the "Hepa Company" make a range of filters
that go from almost useless to really good. The really good ones are mainly
used in the medical field and are Very Expensive.
Most household appliance paper filters Are NOT as good as people are led to believe.
IMPORTANT: Another thing
most people Don't Understand is:
Unless the Polutant goes DIRECTLY into the
Any Type of Filter System, it isn't immediately removed from the air.
It just gradually becomes less and less as the Air in the Room goes through the filter Over and Over Again.
Example: A person is smoking and blowing his smoke into the room, But NOT Directly into the filter.
Unless that smoke is blown DIRECTLY into the
Filter, It takes a long time, Days, Even Weeks, to actually get it "Totally Filtered Out".
Until than, Your Breathing it!
Update, Trigger Coil Now Available:
I Finally Obtained some of these Isolated Trigger Transformers and have Tested them.
They deliver about 4.5 KV output in this Circuit.
I Measured this voltage by connecting the output through a 100 K resistor into a .25 uF @ 10KV Oil filled Capacitor,
charging it and than measuring the output with a 25 KV Probe on my "Fluke Meter".
(You Can't Mesure the output Directly as Volt-Meters Draw More Current than the Trigger coil supplies.)
My Final Cost was $3.00 each US Funds, and I will also sell them at this price,
Plus the Postage Cost to mail them out.
I Can Supply Most of the parts for this project, But Not any of the HV Resistor.
They all have High Voltage ratings and there isn't enough demand for me to buy large quantities of these.
These Transformers Measure aproximately 0.3 inches square by about 0.5 inches high and are potted in a plastic case.
They have 3 Terminals on the Bottom and the HV Terminal on the Top.
All Imformation in this Article is "Copyright protected".
Chemelec
*Copyright © 2004*
