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Another Negative Ion Generator Question

T

Technician

Jan 1, 1970
0
I would like to know about the rules for what will impede negative ion
flow (Ion wind) on the output of a negative ion generator.

It's obvious a metal grill covering the exit portal is a bad idea, but
what about a plastic grill, or even a small fan redirecting the flow of
ions??

Some people are saying the output needles must absolutely not have
anything at all in front of them, and others say it's ok to have
something in front of it such as a plastic grill or a fan as long as it
is not a metallic structure.

Additionally, will a fan actually aid in projecting the negative ions
out into the surrounding atmosphere, or will the natural power of it's
own ion wind be sufficient?

I'm confused. can somebody shed some light on this subject please?
 
H

Homer J Simpson

Jan 1, 1970
0
Technician said:
I would like to know about the rules for what will impede negative ion
flow (Ion wind) on the output of a negative ion generator.

It's obvious a metal grill covering the exit portal is a bad idea, but
what about a plastic grill, or even a small fan redirecting the flow of
ions??

All designs I have seen leave a minimum opening in front of each needle.
It's a pretty weak 'wind'. I don't see why a fan would hurt if it is pushing
and not pulling the air.


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T

Technician

Jan 1, 1970
0
Homer said:
All designs I have seen leave a minimum opening in front of each needle.
It's a pretty weak 'wind'. I don't see why a fan would hurt if it is pushing
and not pulling the air.
This is where I get confused.
I actually purchased a negative ion generator "air purifier" on ebay,
just to see what makes it tick and was surprised at it's configuration.

This particular design is one of those common tower form factor ones you
see for sale at radio shack for around $200 with a dust collecting
"plate" inside which can be removed for cleaning purposes. You can see a
similar item here:

http://cgi.ebay.ca/NEW-IONIC-AIR-PU...3QQihZ010QQcategoryZ14949QQrdZ1QQcmdZViewItem

The high voltage unit is in the base, the metal collection cannister is
in the center, (I assume positively charged or grounded?) and running
parallel to the collector plate are 4 thin bare steel wires around it's
perimeter, which I assume are responsible for emitting the negative
ions. (I could be way off on my assumptions, which is why I'm posting
here!)

The flip up top which opens to allow removal of the cleaning plate also
contains a round black fan (visible in the auction picture) which blows
the air out an exit port in the front of the flip up lid. (the air is
pulled out of the unit by the fan) I don't think there are any needles
even in this design.

Everything about this design goes against everything I've been told is
the right way to design an ion generator, or a dust collector.
This negative ion generator not only has something obstructing it's exit
like a plastic grill, but also a powered fan!

This makes me wonder if the "no moving parts" style negative ion
generator dust collectors are more efficient at emitting negative ions
but poorer at collecting dust, or are the models with fans more
efficient air cleaners as they move more air across the plate, and are
less efficient negative ion generators (less negative ion output into
the surrounding air) because of the fan?
Or are the ones with fans just plain more efficient in all aspects as
the fan and other obstructions the negative ions come into contact with
on the way out of the unit have no effect on them and the fan improves
it's performance?

I guess this is a more specific example of the concept I'm trying to
understand.
Once I understand the true proven design rules, then I can design my own
more efficient purifiers.
Thanks!
 
H

Homer J Simpson

Jan 1, 1970
0
This is where I get confused.
I actually purchased a negative ion generator "air purifier" on ebay, just
to see what makes it tick and was surprised at it's configuration.

This particular design is one of those common tower form factor ones you see
for sale at radio shack for around $200 with a dust collecting "plate"
inside which can be removed for cleaning purposes. You can see a similar
item here:

http://cgi.ebay.ca/NEW-IONIC-AIR-PU...3QQihZ010QQcategoryZ14949QQrdZ1QQcmdZViewItem

The high voltage unit is in the base, the metal collection cannister is in
the center, (I assume positively charged or grounded?) and running parallel
to the collector plate are 4 thin bare steel wires around it's perimeter,
which I assume are responsible for emitting the negative ions. (I could
be way off on my assumptions, which is why I'm posting here!)

The flip up top which opens to allow removal of the cleaning plate also
contains a round black fan (visible in the auction picture) which blows the
air out an exit port in the front of the flip up lid. (the air is pulled out
of the unit by the fan) I don't think there are any needles even in this
design.

Everything about this design goes against everything I've been told is the
right way to design an ion generator, or a dust collector.
This negative ion generator not only has something obstructing it's exit
like a plastic grill, but also a powered fan!

This makes me wonder if the "no moving parts" style negative ion generator
dust collectors are more efficient at emitting negative ions but poorer at
collecting dust, or are the models with fans more efficient air cleaners as
they move more air across the plate, and are less efficient negative ion
generators (less negative ion output into the surrounding air) because of
the fan?
Or are the ones with fans just plain more efficient in all aspects as the
fan and other obstructions the negative ions come into contact with on the
way out of the unit have no effect on them and the fan improves it's
performance?

I guess this is a more specific example of the concept I'm trying to
understand.
Once I understand the true proven design rules, then I can design my own
more efficient purifiers.
Thanks!

==================================================================

These things seem to be a cross between an ion generator and an
electrostatic air cleaner. I'm not sure they do either well. The
electrostatic air cleaners rely on the furnace fan to move the air. The ion
generators don't normally use a fan AFAIK. Hope it helps.

FWIW, if I wanted to fool around with a home design I recall articles on
building both in back copies of Pop Electronics and / or Radio Electronics.
Both are defunct, but bigger libraries have back copies for reference.
 
D

dlzc

Jan 1, 1970
0
Dear Technician:

I actually purchased a negative ion generator "air purifier"
on ebay, just to see what makes it tick and was surprised
at it's configuration.

This particular design is one of those common tower form
factor ones you see for sale at radio shack for around $200
with a dust collecting "plate" inside which can be removed
for cleaning purposes.

Positively charged plate.
You can see a similar item here:

http://cgi.ebay.ca/NEW-IONIC-AIR-PURIFIER-IONIZER-OZONE-TOWER_W0QQite...

The high voltage unit is in the base, the metal collection
cannister is in the center, (I assume positively charged or
grounded?)

Both, probably.
and running parallel to the collector plate are 4 thin bare
steel wires around it's perimeter, which I assume are
responsible for emitting the negative ions. (I could be
way off on my assumptions, which is why I'm posting
here!)

No, you have guessed correctly. The radius of the charged surface
affects the local potential for a given charge. The wires are a small
radius, which yields a high local charge.
The flip up top which opens to allow removal of the
cleaning plate also contains a round black fan (visible
in the auction picture) which blows the air out an exit
port in the front of the flip up lid. (the air is pulled out
of the unit by the fan) I don't think there are any needles
even in this design.

Needles are not required.
Everything about this design goes against everything
I've been told is the right way to design an ion generator,
or a dust collector.

Turn it off and put in the garage. It collects lots of dust. ;>)
This negative ion generator not only has something
obstructing it's exit like a plastic grill, but also a
powered fan!

If a patent relies on the charged air flow to move air, and you make
one that has a powered air mover, you are not violating the patent.
This makes me wonder if the "no moving parts" style
negative ion generator dust collectors are more
efficient at emitting negative ions but poorer at
collecting dust, or are the models with fans more
efficient air cleaners as they move more air across
the plate, and are less efficient negative ion
generators (less negative ion output into the
surrounding air) because of the fan?

Neither and both, to some extent. Ionizing air makes ozone and other
oxidants.
Or are the ones with fans just plain more efficient
in all aspects as the fan and other obstructions the
negative ions come into contact with on the way out
of the unit have no effect on them and the fan
improves it's performance?

Plastics can be statically conductive, depending on what they are
"alloyed" with, and can be the positive plate.
I guess this is a more specific example of the
concept I'm trying to understand. Once I
understand the true proven design rules, then I can
design my own more efficient purifiers.

Good:
1) don't use ion anything,
2) don't use UV of longer wavelength than 254 nm,
3) HEPA filter the air,
4) carbon filter for chemical activity, probably bathed by UV,
5) keep humidity at some settable value.

Using ozone to occasionally chemically clean stuff is excellent.
Chronic exposure by design is a lawsuit just waiting to happen.

David A. Smith
 
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