Choosing appropriate nozzles, pump or other related components for High Pressure Aeroponics


#1

Hey guys,
I’ve spent the last year building and testing an aeroponic build, with my focus being on growing lettuce.
I’ve been using these nozzles:

(Note that the information shown on regarding the operating conditions for those nozzles were a recent addition to the page, and were not available when I made the purchase)

And this pump:
http://www.communica.co.za/Catalog/Details/P0118896118
which is basically a 100psi 4l/min diaphragm pump.
I have not used a pressure accumulator tank, and my feed line consists simply of resevoir-> pump-> nozzles->resevoir, ie. a closed system.
I’ve been running my system on a 5s on, 20s off frequency, as I noticed that a slightly longer frequency of 8s on, 80s off was resulting in my roots drying out once they grew beyond a certain point.
Based on recent information, I’ve concluded that my system is not a true HPA system.
This information includes

  • The general shape of my roots is a slightly conical (oriented with the point down) cylinder, with a top width of approx. 150mm, a bottom width of approx. 50mm, and a total length of approx. 350mm
  • The thickness of individual root hairs vary from roughly 2mm diameter to 0.5mm diameter
  • The developement of fine root hairs, as seen in an image posted by @Atom, is for the most part non-existant
    I will upload pictures of my build, and my roots shortly.

I was previously under the impression that nozzle orifice diameter and pump pressure were my main variables as far as water droplet size was concerned, however I now believe that this might not be the case.

I would appreciate any help with that can be offered to me, especially a guideline to choosing appropriate nozzles. What features am I looking for, aside from orifice size?
As far as pumps are concerned, would my current pump be adequate, if I only changed my nozzles?
What would the effect of an accumulator tank be as far as achieving true HPA be, aside from consistent pressure?

If possible, could someone post a link to an example of suitable components?

Thanks people, your help will be greatly appreciated.


#2

@wsnook keeps this updated still I think: Aeroponic design guideline roundup

https://forum.openag.media.mit.edu/search?q=aeroponics

@seiche @Atom are geniuses.


#3

Thanks @Webb.Peter. perhaps I posted a topic prematurely :stuck_out_tongue:
I should probably read every single thread on this forum regarding aeroponic setups first… (already on it)… I’ll get back to this topic in a day.

Here’s an aside though, while I do that:
How does one easily ascertain whether or not a setup is adequate, assuming for the moment that aspects like timing, nozzle placement etc. are all as they should be (they’re not- in my case). The most robust way would be to measure water droplet size, but i don’t have the resources to purchase a device capable of such a measurement. Is there an existing sensor, or obvious tells? Are the indicators I mentioned in post #1 adequate? @Atom, could you provide any insight here?


#4

Your nozzles require a minimum of 22 bar or 319 psi. Your pump only produces 100 psi. You will need to find some new nozzles. I believe @Atom recommends the hypro afd series. I have found that the red low flow version of these https://www.dripworks.com/superfine-misting-nozzle work well too. They both contain adv’s to help reduce overspray. Your pump will work with either of them, but it would benefit you to add an accumulator to your system. When your system is working properly, you will be able to tell by your roots. Atom’s picture is a great example.


#5

In rereading your first post, are you using solenoid valves? They allow you to have very short spray times, with no overspray. Without them it will be hard to achieve a true HPA system. The accumulator tank keeps your line pressure stable instead of ramping up and down with the pump, once again reducing overspray


#6

Hey… Thanks for pointing out that fact about the nozzles. The Hypro Series is pretty hard to come by in South Africa, but im working on getting a few imported. Ive already started looking into an accumulator tank. Ive spent the last few days reading through all the threads on this forum, and its proven to be very insightful!

Yes, I am using solenoids. At the moment, theyre operating as pressure relief valves, where a solenoid opens once my spraying interval is over, allowing any excess pressure in the system to be immediately exhausted. Thanks again!


#7

If the springs are removed from the nozzles they may work on 100psi but its not ideal. I dont think he`s using an accumulator or solenoid(s). Running 3500 pump cycles a day will eventually take its toll :wink:


#8

@Ashraf This company http://www.spraynozzle.co.za/liquid_spraying.htm carries BETE nozzles. Their ultimist line, specifically UML63M, looks like it would work well for you and comes in plastic bodies http://www.spraynozzle.co.za/pdf/liquid%20cooling%20bete/BETE_UltiMist-metric.pdf
Not sure how much they cost, I know the stainless ones will cost an arm and a leg, but they might be a good choice if you can’t import the hypro’s


#9

Thanks dude! I’ve actually already been in contact with them in the last week. They stock hypros as well, but the AF series, not AFD.

Im in 2 minds right now. I either go for the hypros AF with “anti-drip” strainers, or the nozzles you’ve mentioned. The pricing isn’t a whole lot different, however the bete nozzles are cheaper and have fewer moving parts. However, fittings are a bit of an issue for me, as most that are available to me are metric sized. Finding a 1/8" fitting for the bete might prove difficult, while a 1/4" for the male body of the hypros may be simpler.

Another key difference between the nozzles are the flow rates, with the bete being almost half that of the hypros.

I’m curious, what’s your take on it? Which one of the two setups would you recommend, if fittings were irrelevant?

Thanks, really appreciate this feedback. You guys are so incredibly helpful.


#10

Apologies, I meant HAF, not AF. Attached are the data sheets for both of the nozzles.

BETE_UM-metric.pdf (391 KB)

HYPRO MISTING.PDF (1.21 MB)


#11

I think both nozzles would work well. You want to match your nozzles to your chamber, meaning coverage, pattern and total flow rate. You will have to figure that out as each chamber and situation is different. ie 2 of the HAF might give the same coverage as 4 of the BETE.