An Atomizer for Aero

aero45

Member
Hey Atomizer!
I did the math on my set up and I am misting 4oz every click on my 48 pin growcolt timer. You stated maximum saturation its at .001oz a gal going off your .03oz for 30gal numbers. That for my 14gal tote comes out to be 0.014oz until maximum saturation, that number is so small, its that really possible?

Referenced here, http://answers.yahoo.com/question/index?qid=20070810132455AAfCf71, a drop of water is .003oz, meaning that full saturation for my 14 gal tote would be roughly 4.67 drops, 5! drops of water.

Are you sure about your numbers or have I made a miscalculation? Also, wouldn't the root growth and the plants ability to suck up fluid greatly influence this? I only ask b/c I want to effectively dial my system in.

Thank you for your help.
 

Atomizer

Well-Known Member
If the 5 drops of water are converted into the correct droplet size it will fill the entire space. If you have just 5 large drops, you wont get the coverage even though it contains exactly the same amount of liquid. Large droplets fall to the floor rapidly, wet floor = nft, not hp aero. Very small droplets evaporate before they reach the target.

Control over the mist is key. Deliver too much in one hit or use mist with too large a droplet size and you might as well be using a watering can.

Wet is a relative term to describe levels of dryness :smile:
The picture of the mist i posted earlier in the thread was taken a full 18 minutes after the misting pulse had ended, looks plenty wet enough to a root. Imagine how "wet" the chamber volume is directly after the misting pulse.

We imagine plants taking up moisture the way we would do it. The difference is that we would die of thirst if we had to "drink" mist, plants can thrive in what appears to be a fairly dry fog. This mindset is probably the reason so many plants get overwatered on a regular basis.

Edit: This may help get your head around it.
1ml of water (0.003oz) is enough to form a single droplet 1240um in diameter. Its not what you might call big :)
The same 1ml can form 3,733 x 80um droplets, 15,290 x 50um droplets, 70,787 x 30um droplets or 15,290,000 x 5um droplets.
A gallon of chamber volume equates to a "box" roughly 6.13" x 6.13" x 6.13" in size. Its not that large considering over the 5-80um size range you`ll have between 13 and 52,500 droplets per cubic inch after each misting.

That for my 14gal tote comes out to be 0.014oz until saturation, that number is so small, its that really possible?
work out the number of 5-80um droplets you`ll have per cubic inch and then decide :)
 

aero45

Member
Ok, so I am on board with the volume of water need each misting. My follow up is how often do you mist this and second, is their any need to have a return to the reservoir? Last, 2 part q here, if we misted .014oz every min, that comes out to be about 20oz a day. Is their any need to flush my nutrients if I don't include a return and could I just mist my entire reservoir, being 5gal, that would take 32 days with out fumbling with it? Thanks again for all help!
 

Bob Smith

Well-Known Member
Atomizer, sent you a PM whenever you get a chance - I'm doing a vertical TAG setup (will be setup within the next week) and would love some of your input.

Sorry for the slight threadjack.
 

Atomizer

Well-Known Member
Aero
The misting duration is set by the saturation point and doesn`t change. The number of cycles is varied to meet the needs of the plants.
Decreasing the cycle time increases the misting frequency without affecting the saturation unless you go too short. The droplet size range, coverage and control over the misting duration are equally important and sounds easy.
Coverage and control are difficult as they interact. The more nozzles you run for coverage, the higher the flow and the shorter the misting duration you need.

How are your roots doing and what kind of plants are they? looks like some kind of cabbage or lettuce.

Bob
I`ll take a look.
 

Kingofpoon

Active Member
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
View attachment 1372620

i love when people try to complicate simplicity

that attached photo which you claim to be a highly advanced atomising disc is in fact a picture of a 1 1/2 inch dremel saw used for plastic having teeth ranging from 36 tooth to 200 tooth

how do i know this you ask becuase i read this article the saw your picture pulled out a old dremel tool and ordered a hss 160 tooth 1 1/2 inch saw mounted and just like that had a "precision engineered atomising disc"

runs good at around 3k rpms but at 7k works incredible if you willing to tolorate that kind of noise as stated before a brushless dc motor would fix noise and reliablity problems but didnt have one of those lying around i know this is a little old just thought id throw it out there if some one else thought this was interesting but didnt want to spend all that expesally if like me you already had pump and timer

two last notes it may not be true aeroponics but shows promise hopefully in the next week i can show some root growth and second if you do plan to do this i recommend you stay away from the cheapest hss blade you can find went though 3 companys before i found one i like the other to had ununiformed teeth which even for a shyts and giggles projects i wasnt willing to proceed with
 

aero45

Member
Not sure which bit your talking about, the one in the photo I uploaded doesn't have any teeth. The one Atomizer uploaded does. Intresting though, please upload your project! I would love to see. I work with the people that put the first one together and they have switched over to a new motor that does 30k w/o the noise. I am waiting to see the final project. They also are creating a board that will control your lights, timer and pump, pretty cool stuff!!!
 

Atomizer

Well-Known Member
I don`t know how he made the leap from saw blade to atomising disc :)
The roots look ok Aero, you could do with a camera with a macro function though. The roots underneath the pot look pretty good, looks like they are sheltered from the bulk of the spray judgng by the amount of standing water on the outside of the netpot.

You might gain some control if you can seperate the disc rotation and water delivery. Get the motor upto speed first and then drop a set amount of water on it.
The disc will slow down when it gets hit with water so.. the more no load rpm you have the better.
 

Atomizer

Well-Known Member
i love when people try to complicate simplicity

that attached photo which you claim to be a highly advanced atomising disc is in fact a picture of a 1 1/2 inch dremel saw used for plastic having teeth ranging from 36 tooth to 200 tooth

how do i know this you ask becuase i read this article the saw your picture pulled out a old dremel tool and ordered a hss 160 tooth 1 1/2 inch saw mounted and just like that had a "precision engineered atomising disc"

runs good at around 3k rpms but at 7k works incredible if you willing to tolorate that kind of noise as stated before a brushless dc motor would fix noise and reliablity problems but didnt have one of those lying around i know this is a little old just thought id throw it out there if some one else thought this was interesting but didnt want to spend all that expesally if like me you already had pump and timer

two last notes it may not be true aeroponics but shows promise hopefully in the next week i can show some root growth and second if you do plan to do this i recommend you stay away from the cheapest hss blade you can find went though 3 companys before i found one i like the other to had ununiformed teeth which even for a shyts and giggles projects i wasnt willing to proceed with
Sounds like you are confusing computer designed high speed rotary disc atomisers with rotary sprinklers like the GH Rainforest uses. The rainforest spinner was designed for the task unlike a common or garden dremel sawblade but at the end of the day its still just a glorified sprinkler. :)
This may be a useful starting point for research, http://www.micron.co.uk/why_cda

that attached photo which you claim to be a highly advanced atomising disc is in fact a picture of a 1 1/2 inch dremel saw used for plastic having teeth ranging from 36 tooth to 200 tooth
As far as my pic being some kind of dremel sawblade..good luck finding this in a dremel tool catalogue lol, hopefully you didnt spend a lot on the 160-tooth sawblade you mistook it for ;)
 

Attachments

Atomizer

Well-Known Member
It could be an optical illusion but it appears to have a stringy quality about it. Perhaps the ligaments arent breaking up into droplets and the disc is generating cylinders not spheres :)
 

aero45

Member
It's an illusion, they are singular droplets, and moving in circular currents so the camera blends them. You can get an idea of the size though. The root structures are finally gaining some steam, the plants def. did not enjoy their dirt to aero move, lol!
 

pounce

Member
So, is it a Dremel or similar motor in that PVC pipe?

I'd imagine you could make that thing a lot smaller and a lot safer if you simply used a DC motor. You don't actually need anything near the kind of torque a hand held rotary tool outputs. You just need high RPM's from what I can tell.

Using AC near water like this can kill someone. Just think about someone adjusting the mount on that device and having it drop into the water. Human instinct is going to kick in and the person is going to reach for the device as it's dropping. ZAP!

At the very least you will have issues with a rotary tool getting that much humidity.

The concept is good though so keep advancing. Safety first :)
 
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