[sci.electronics] Negative Ino generators / Electrostatic air cleaners

hgw@MATH.UCLA.EDU (03/15/88)

Are Negative Ion Generators and Electrostatic air cleaners one and the same?
I'd like to build one of these air cleaners (my home seems to be a dust farm)
but don't know how.  There are lots of stored that sells these things but I'm 
looking for a heavy duty/giant size cleaner.  I know Sears sells one of these 
cleaners as a replacement for the regular fiber air filters in central air
conditioning systems, but costs and arm and a leg.  I've looked around in 
hardware stores but nobody seems to have one.  Anybody know where I can get one 
of these monsters (20" x 20" or alittle smaller) or better yet, have a circuit
for building one of these?  

Another question.  Can I screw myself up by ending up generating positive
Ions thus making everybody angry at each other?  I'm assuming a few things.
First, dusty air flows through a charged metalic screen (either pos or neg) 
and then through the other metalic screen (the opposite charge of the first
screen).  If the first screen was negative and the second positive and since
negatively charged particles (the dust) is attracted to the positive screen,
the air is clean.  But since the positive screen was the last thing the air
came through, will the air be positively charged?

If the first screen was positive then I assume the negatively charged particles
from the negatively charged second screen would jump against the air flow to 
the first screen.  Since the second screen is negative, the air would be 
negatively charged and we'll all be happy.  How close am I to the truth?

Unless it should be that the air should flow across these charged plates
stacked one atop another with air space in between.  I would make sense but
wouldn't the plates neutralize each other and I end up with on ions?  Is this
better for me?

Time to shut up.  Thanks in advance.

          |     |                             --------
------>   |     |                   ----->     ------
air flow  |     |          OR       air flow  --------
------>   |     |                   ----->     ------
          |     |                             --------
         -/+   +/-                             ------
          screens                          Alternating pos/neg charged plates



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Harold Wong         (213) 825-9040 
UCLA-Mathnet; 3915F MSA; 405 Hilgard Ave.; Los Angeles, CA 90024-1555
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