my gravity fed air atomizing aeroponic system

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oxanaca

Well-Known Member
thats a sweet chamber. im waiting for you to spill the beans though and tell me what nozzle(s) you have chosen. will it(they) be pressure fed?

im thinking about using these bete XAAD nozzles
one of my friends on here gave me this little bit about this bete nozzle. can you look at the specs and tell me if this nozzle is a fighterjet or a yugo?
theres more info on it on betes website. it sounds like i can get them for around $47 usd in NI/BRASS

I have estimated the following performance information for the XAAD050 spraying at 30 PSI water and 34 PSI air.
Nozzle: 1/4" XAAD050
Liquid Pressure: 30 PSI
Air Pressure: 34 PSI
Flow Rate: 1.2 GPH (water)
Drop Size:
DV0.1: ~ 18 microns
DV0.5: ~ 44 microns
DV0.9: ~ 68 microns
 
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oxanaca

Well-Known Member
i hear about this sauter mean diameter. i found this

D32 — Sauter Mean Diameter Sometimes abbreviated to S.M.D. The diameter of a
droplet whose ratio of volume to surface area is equal to that of the complete spray
sample. It is defined as the cube of the Volume Mean Diameter divided by the square
of the Surface Mean Diameter. The Sauter Mean Diameter is the best indicator of
a spray’s performance in processes involving complex interactions with the droplets’
surface and volume, such as spray drying, evaporative cooling, scrubbing and gas
quenching. The Sauter Mean Diameter is typically about 80% of the Volume Median
Diameter.

and this

DV 0.5 — Volume (Mass) Mean Diameter Sometimes abbreviated to V.M.D orM.V.D.
The diameter which divides the volume (or mass) of the spray into two equal halves.
Thus half of the total volume (or mass) is composed of droplets smaller than the
Volume Median Diameter, and half of diameters larger than the Volume Median Diameter.

i dont have the the surface mean diameter unfortunately, but i do have the volume mean diameter (DV 0.5) so based on the Sauter mean diameter being around 80% of the volume median diameter i should have a sauter diameter of 35um.

what sauter(D32) or DV 0.5 diameter am i looking for?
 
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Atomizer

Well-Known Member
Heres an example of a PF AA nozzle spec that provides a range of droplets from 5 to 80 microns. The droplet distribution, flowrate and pattern are equally important. The flowrate and pattern are geared to the chamber size and layout. A nozzle with a lazer tight pattern and one that puts out 100gpm could both produce the ideal droplet size range but they wouldnt perform equally well in the same chamber size ;)
droplet data.jpg
 
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oxanaca

Well-Known Member
he found a plant that had very hairy roots growing it out the bottom, so he put them in. we currently have hydro roots but were not to worried, i will wait until i get my system inside to chase the hairy roots again.
the tops however are growing slow. we upped from 600uS to 1000uS were hoping for more top growth.

. im using a #4 nozzle on the half with the solar coleus. and a #5 on the side with the established wandering jews.

heres a video, i couldnt unplug it today so you may want to fast forward. i sort of shut the camera off to soon ill replace this tomarrow

[video=youtube;XYhpTqB2UEA]http://www.youtube.com/watch?v=XYhpTqB2UEA&feature=youtu.be[/video]
 
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oxanaca

Well-Known Member
Atomizer said:
Heres an example of a PF AA nozzle spec that provides a range of droplets from 5 to 80 microns. The droplet distribution, flowrate and pattern are equally important. The flowrate and pattern are geared to the chamber size and layout. A nozzle with a lazer tight pattern and one that puts out 100gpm could both produce the ideal droplet size range but they wouldnt perform equally well in the same chamber size ;)
View attachment 2644852
Click to expand...
i agree with you completely. thats what i like about this nozzle. at those setting you get a misting angle of around 70 degrees . much better than the 30 degrees i can get with my delavans.

it states that at
6 inches will have a mist plume that is 7 inches across
at 9 inches i will get 8 inches across plum
at 15inches i will get 10 inch across plum
at these pressures i will get a 7 foot plum

im sure you have some sort of geometry equation you can use to get the exact angle.

also i wasnt able to see your table you uploaded
 
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oxanaca

Well-Known Member
i was looking at the setting you recommended for my #5 delavans and it looks lke you shoot for 0.5ml per misting cycle per 100Liters. is this right.

my #5 nozzles put out 0.72ml per second at 600mm gravity height, 1.4bar. 2600ml/60/60=0.72ml/sec
so two nozzles at 0.72ml/second equals 1.44ml/second. if you run that into my 280Liter box you basically get 0.5ml per second.

based on this logic i should run 1 bete XAAD050 nozzle for 1.2 seconds based on 1.26 ml per second. at 30psi water and 34psi air
1.2gph>4536ml/60/60=1.26ml/second
 
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Atomizer

Well-Known Member
The roots are looking much better, that lettuce doesnt look very appetising though ;)
The minimum and maximum saturation levels for a 100L chamber, Minimum: 0.000027ml, Average: 0.4ml, Maximum: 0.9ml.
Ideally, you want a light haze of mist still hanging in the chamber when the next pulse hits. The ideal misting frequency and quantity of liquid delivered will change as the roots grow but you dont want the chamber to be completely clear of mist as that gives you a definited wet/dry situation. You want a constant environment somewhere between min and max saturation that is geared to the roots needs at that particular time. That includes day/night, not just the roots stage of growth :)
 
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oxanaca

Well-Known Member
Atomizer said:
The roots are looking much better, that lettuce doesnt look very appetising though ;)
do you know why my top growth suck so bad on my solar coleus"lettuce" compared to plants that i transfered to soil at the same time? im was running 6ec and recently bumped it up to 1ec. im contemplating bumping it up to 1.3 til i see N overdose.
The minimum and maximum saturation levels for a 100L chamber, Minimum: 0.000027ml, Average: 0.4ml, Maximum: 0.9ml.
Ideally, you want a light haze of mist still hanging in the chamber when the next pulse hits. The ideal misting frequency and quantity of liquid delivered will change as the roots grow but you dont want the chamber to be completely clear of mist as that gives you a definited wet/dry situation. You want a constant environment somewhere between min and max saturation that is geared to the roots needs at that particular time. That includes day/night, not just the roots stage of growth :) are you saying i should have another timer on a relay or somthing to switch to another time setting at night?
Click to expand...
hows your new system going? have you added insulation yet

the video i uploaded yesterday really sucked, ill upload something im more proud of tonight.
 
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Atomizer

Well-Known Member
I`ve no clue on the normal hydro nute strength for solar coleus, i`d just bump it up a little at a time and see what happens. Its easier to get a handle on the nutes with the more run of the mill stuff like basil, lettuce or toms. 1/4 strength or less is a good place to start with AA.
I replaced the swiss cheese lid on the new chamber, its still waiting on the insulation as i got waylaid building another HPA chamber to put further up the yard :)
Having the option to run a different timing cycle can help prevent the roots being overmisted at night.
 
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oxanaca

Well-Known Member
i liked the swiss cheese lid i think it looked pretty versatile, you could have a variety of different plant numbers/ sizes. ive never seen any of your hpA chambers before, i remember you talking about a cylinder shaped vertical outdoor grow, how did that turn out,?
 
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Atomizer

Well-Known Member
I can still use the swiss cheese lid but a lot of the holes are pretty close to the edge, it was originally on the nft system. Checking PH/EC daily was way too much work :)
The vertical idea was a 6ft high doughnut with a 2ft cavity wall, i did a test fit and a rotation test but didnt get around to putting it online. Its a viable option and may happen one day as all the hardware is in the shed, two pairs of steel trampoline frame rings (8ft and 12ft), rotation motor, timer etc.
 
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oxanaca

Well-Known Member
Atomizer said:
I can still use the swiss cheese lid but a lot of the holes are pretty close to the edge, it was originally on the nft system. Checking PH/EC daily was way too much work :)

ive always thought anything that required reciculation of nutrients was lame. if i cant have my DTW aero, youll find me with my coco coir.

The vertical idea was a 6ft high doughnut with a 2ft cavity wall, i did a test fit and a rotation test but didnt get around to putting it online. Its a viable option and may happen one day as all the hardware is in the shed, two pairs of steel trampoline frame rings (8ft and 12ft), rotation motor, timer etc.
Click to expand...
so do the plants go in the inside or outside of the donut? also do both the inside and outside drums rotate or is it just one or the other.

 
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Atomizer

Well-Known Member
The plants go on the inside and outside walls, the mist is inside the cavity. The whole chamber was designed to rotate intermittantly at 5 degrees every 10mins. The nozzles are suspended from above so as the chamber rotates, the root positions move in relation to the fixed nozzle positions. All the plants get to face the north and south side of the greenhouse throughout the day, so none are permanently sitting in shade or baking in the sun. There`s roughly 376sqft of planting area in a 113sqft footprint.
 
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oxanaca

Well-Known Member
that sounds pretty sweet, im glad you explained it to me:) i had always wondered what you ment
is there a shaded area in the inside of the drum?
 
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oxanaca

Well-Known Member
also what your opinion on flat fan vs hollow cone as far as coverage goes?
im thinking of purchasing both from bete.

it seems external mix nozzle are ment more for paint applications, or applications using viscous fluids. is this correct?
fatman told me that internal mix nozzles(compared to siphon or external) use less compressed air per volume of liquid, to atomize the fluid in the right droplet range. would you agree with this? it seems logical to me, but ive never used pressure fed nozzles yet.

i never realized it until recently but my gravity feed paint gun is external mix. i used it once a few years ago, and thought it was the biggest piece of shit. i had my air pressure set really high. and it went though paint really fast without getting anything painted. it mostly went into the air. if only i had gotten into aa aero earlier. i would have realized i needed to drop my air pressure to increase my droplet size and paint the boards instead of the air.
 
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Atomizer

Well-Known Member
I`ve never used hollow cone but it seems they can manage a smaller droplet size than the equivalent full cone. Air consumption isnt as important as getting the right flowrate, droplet size range and coverage. If the cost of compressed air was a major factor, no one would be doing AA :) The air cost for a 4x2 chamber is about 2.5kw per week, the running cost of a typical LPA waterpump would be much higher. A 25w pump running 24/7 for a week is 4.2kw
The downside of external mix nozzles is they only come in a flat fan pattern.
 
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oxanaca

Well-Known Member
im not so worried about the cost of the compressed air, but more interested in being able to run as much square footage off of a 80 gallon belt drive as possible

also if you check out this page bete makes an external fed in narrow round, althought as im starting to see based on experience with my delavans wider is definitely the way to go.
http://www.bete.com/products/xa-dir.html


since bumping up my EC i have noticed better growth rates, and the plants are showing a better color. im currently at 1100EC im thinking about going to 1300 tomarow.
 
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oxanaca

Well-Known Member
would you consider a nozzle that has a spray angle of 30 degrees to be a narrow cone or a full cone. or is my terminology flawed.
 
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