An Atomizer for Aero

aero45

Member
I did not make it, I help them package and move aero equipment. The device uses an electric motor and breaks the water into a fine mist that floats. I think the mist could be blown down sections of 4" pipe and circulated for larger grow operations, that is still comming down the line. It is truly 100% aero though and that is the most exciting part, bringing commercial grade down to the independent grower!
 

Mike Young

Well-Known Member
Seems like it would be a cheap alternative to expensive pumps & accumulators with fancy solenoids & mister heads. Me thinks I'm gonna try to build one myself.
 

aero45

Member
Much cheaper than a professional setup and the same end result, 30-80 micron sized droplets, no clogs, hassle. They are currently selling the mister/atomizer with 132 gph pump and Aero timer with 50 second intervals for $95. That's a hell of a deal! All u need at that point is a tote and some net pots.
 

Atomizer

Well-Known Member
You wont get the same results if the flowrate is excessive, a gallon of water converted into 30-80 micron droplets is still a gallon :)
For a 30gal tote, 0.03oz of liquid in one hit is the maximum saturation point. The rotary atomizer could acheive that maximum saturation level (30gal tote) in 50 seconds if you could feed it with a steady liquid flowrate of 0.02gph..thats about 15 teaspoons.
The other issue with rotary atomizers, apart from noise, is the motors don`t last long. They need to run at 15,000-20,000rpm to generate 30-80 microns.

The initial onslaught of droplets in the other video (7 seconds in) looks closer to 1500 micron. Judging from the inside wall of the tote, the roots will be instantly soaked and any fine root hairs that do appear will be destroyed by the force of the impact. http://www.youtube.com/watch?v=Yn920j2VIrg&feature=related
 

aero45

Member
Thank you for your feedback Atomizer!
I am not sure if we watched the same video, I noticed the one you posted was not the same link, here is the correct one: http://www.youtube.com/watch?v=ZKsElmoVnpA&feature=youtube_gdata_player

Never the less, I will assume you did watch the one i was disscusing. Keep in mind that the water on te sides of the tote was accumulated from a day of testing and not just a single burst of atomized water, you may be right about flow rate delivered to the atomizer, originally we were running a much smaller pump, if I had to guess... 4gph. The only problem with that was we couldn't get good video of it being it was such a small amount of mist.

As to saying the initial mist was 1500, let's be fair here, this video is far from high quality and to make a judgment call like that on a pixulated video is outside of what can be measured. The atomized cloud of water you see is light enough that you can place a tissue in the tote and pull it out with out it waving around or being anything less than it just bearly being noticeably touched with water, it is truly highly atomized water. We have produced 15 of these now, the first one being over a year ago, still no fails, the motor is running at 1/3 of it's normal operating range. Even if they only lasted 2 years, at $65 a pop for just the atomizer, I believe that is cheaper than running just about any high flow pumps.

Again, thank you for your feedback!
 

Deximus

Active Member
They need to run at 15,000-20,000rpm to generate 30-80 microns.
If the droplets are formed by centripetal force overcoming surface tension of a film of liquid, wouldn't the droplet size be a function of both RPM and disk diameter? That looks suspiciously like a dremel grinding wheel ;)

A brushless DC motor would help solve the mechanical reliability and noise problem. Personally, I'd just build two and stagger a pair of timers, with one resetting the other to keep them synchronized.
 

aero45

Member
What is a micron you say? Here is a link that lays it out beautifully! http://www.pecuniary.com/newsletters/microns2.html

In short, fog is .5 to 20 microns.
Mist is 20-150 microns and rain is everthing larger than that, in the aera of 1000 microns usually.

It is clear in the video that this is not fog nor rain, it is mist, the ideal aero environment.

Again, all of the units have ran great, the original is a year now and still purring nicely, and the sound is very lite, see the video.

http://www.youtube.com/watch?v=ZKsElmoVnpA&feature=youtube_gdata_player
 

Atomizer

Well-Known Member
If the droplets are formed by centripetal force overcoming surface tension of a film of liquid, wouldn't the droplet size be a function of both RPM and disk diameter? That looks suspiciously like a dremel grinding wheel ;)

A brushless DC motor would help solve the mechanical reliability and noise problem. Personally, I'd just build two and stagger a pair of timers, with one resetting the other to keep them synchronized.
A rotary atomising disc is precision engineered, a grinding disc wont create the correct droplets at any speed ;-)

The droplets are creating by ridges in the disc which end in teeth at the perimeter of the disc.The rotation, ridges create thin strands of water from the teeth which break up into droplets. Droplet size is a function of speed, disc design and flowrate.

How do i know? I have one thats gathering dust ;-) I interrogated the tech dept of the company that design and make them. This one generates 50um vmd (Dv0.5) at 15000rpm. Its noisy and doesn`t provide tight enough control for true aero use...another experiment that ended up in file 13 even with the backing of solid accurate reseach lol

Hundreds of tiny channels (ridges) on the back of the disc end up at the teeth
disc atomizer teeth.jpg
 

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Atomizer

Well-Known Member
As to saying the initial mist was 1500, let's be fair here, this video is far from high quality and to make a judgment call like that on a pixulated video is outside of what can be measured. The atomized cloud of water you see is light enough that you can place a tissue in the tote and pull it out with out it waving around or being anything less than it just bearly being noticeably touched with water, it is truly highly atomized water.
The droplets below 50um are not too visible to the naked eye. Unless you`ve had it lab tested you can`t really claim any droplet range with certainty.

Assuming the full flow from the pump (no losses) is turned into single droplet sizes you`d get 60 million x 100micron per second. 80 micron would be 114million per second and at the visible threshold of 50 micron you`d get 470million per second.
The human eye isn`t capable of telling the difference between them given the timescale. It may be worth looking into having them tested professionally with something like a Malvern 2600C analyser so you have the concrete data. Its not a machine worth buying unless you have very deep pockets, a used one costs around $12,000.

We have produced 15 of these now, the first one being over a year ago, still no fails, the motor is running at 1/3 of it's normal operating range. Even if they only lasted 2 years, at $65 a pop for just the atomizer, I believe that is cheaper than running just about any high flow pumps.
High flow pumps are only used for low pressure aero so you may be right. With the first unit running for over a year there must be a few pics of the root structure? The youtube vids only demonstrate the mist in empty chambers unless i missed it.
 

aero45

Member
I will post some root growth pictures of the current system I posted as they come, while I'm at it, anything else you want to see?

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Atomizer

Well-Known Member
nope, that`ll do fine thanks Aero ;-)
I understand that getting a pic of <100um mist isn`t easy but it is possible.
Its mostly invisible unless you use high res and get the sun to highlight the larger droplets. The mist in the pic has droplet sizes ranging from 8um to 95um.
mist.jpg
 

Deximus

Active Member
Hey Atomizer, I had a question regarding netafim foggers. If you can spare a moment, it would really help me finish hammering out my design. Is there a way I can get in touch with you or should I create a new thread here?
 

aero45

Member
So here is a picture of the first root sprouts after a dirt to aero transplant, day 3, pretty rough for the plant but all six are pulling through very nicely and growing.
 

Atomizer

Well-Known Member
Hi Aero
The transition from soil to hydro is rough, from soil to hp aero is even more of a leap. Once the roots get clear of the netpots, the hp root structure should start kicking in.
 
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