Hi /diy/ I'm working with gases and pneumatic tanks and I'm wondering if any of you have a lot of experience?
I want to experiment with co2 enriched horticulture.
My plan is to use a 24 oz Paintball tank with a low pressure regulator. The regulator limits the pressure coming out of the tank to 200 psi which is low enough for my electronically controlled gas solenoid to moderate. I want the solenoid to open when the co2 drops below a certain ppm. This is going to be detected using mq-135 gas sensors, one at the top of the enclosure, one at the bottom, and one outside to detect leaks.
My concerns are the following.
1.) Will pressure continously build up between my regulator and the solenoid
2.) if so how can I avoid that without a release valve that leaks gas?
3.) What is a good co2 flow meter for use with microcontrollers?
I think you're going to need a bigger tank.
>>907620
this is for less than 1 sq meter with controlled release.
>>907577
Its readily apparent you have no fucking clue what you're doing.
A 24oz container of CO2 will only take up 13.5cu.ft of space at room temperature and sea level.
Using this small of a tank for anything other than a single plant in a small container would be pointless.
If this is for something hobbyist related, such as a mini greenhouse or the like, you are better off using nature to raise CO2 levels. I have a 25' greenhouse that I put compost piles in during the winter. Put of plenty of heat, moisture, and CO2
As to your questions, no. The pressure will not build up: its called a PRESSURE REGULATOR for a reason
>>907669
I dont know what crawled up your ass but
>Using this small of a tank for anything other than a single plant in a small container would be pointless.
you described what I'm doing...
It appears YOU actually have no clue what I'm doing so fuck off and stop acting like a brat. The 13.5 cu. ft of CO2 is a ridiculously high concentration and would kill anything trying to grow within its area. I'm trying to increase the concentration in the air by much smaller amounts.
>>907674
You come here asking questions on something you don't know anything about and turn on someone with more experience, knowledge and common sense...
Why don't you just
>"fuck off and stop acting like a brat."
Go learn about partial pressures before being this stupid.
>>907577
>1.) Will pressure continously build up between my regulator and the solenoid
I work with a few different gasses and regulators. the pressure between the regulator and the solenoid will not exceed the pressure setting on the regulator, except in the event of a failure. As the pressure in the tank drops the pressure setting on the regulator may need to be adjusted.
I dont have any answers for your other two questions, good luck with it tho
>>907723
Incorrect again.
I DO know something about what I'm doing, you're assuming I know nothing. Just because I have questions about a subject doesn't make me completely ignorant.
You fit the profile of the shitposters that ruin this board. Someone posts a legitimate question just to be responded to with "ur dumb" and every reason why something isn't going to work. Youre that guy, and people like you ruin the creative place this board used to be.
People should be allowed to ask questions here and get answers better than that. If you anonymously posted a question about a subject I know more about than you, I wouldnt demean you and discourage your project. I would help you to the best of my ability, and if there were challenges I would constructively address them.
>>907933
It felt like that what the case, it just seemed like the 800psi tank would continuously push gas out the regulator at 200 psi and overwhelm the solenoid.
So basically I should just put in a 300 psi release and my solenoid will be fine.
When my tank gets lower and pressure drops how does that affect the regulator? Is limiting 800 psi to 200 is different than regulating 400 psi to 200 if the regulator can do both?
Have you heard of any inexpensive digital/analog regulators?
>>907577
I would do it like this:
1)larger CO2 bottle (unless its for your special herbs in your grow tent)
2)magnetic valve 12v normally shut
3)CO2 detector
4)Microcontroller
Evertime the microcontroller detects less than 1300ppm CO2 the valve opens for 3 seconds.
>>907968
We know what you're doing, just like the other 9000 hippie fags growing dope but the don't have the attention span to check out one of the 100 or so articles on the subject.
>>907968
>When my tank gets lower and pressure drops how does that affect the regulator? Is limiting 800 psi to 200 is different than regulating 400 psi to 200 if the regulator can do both?
>>907933 here
lets say you start with 800psi in the tank and the regulator set to 200psi. when the tank is down to 400psi your regulator may be outputting 150psi.
im not sure if the curve is linear, but i do know that the output pressure will drop as the input pressure drops. youll need to check/adjust the regulator if the 200psi is mission critical.
>>909531
thats less of a system than I currently have and it will not work, for starters the solenoid isn't going to hook directly onto the tank, it must be regulated.
>>909646
in two engineering competitions doing NASA research.
I hope one day when you still have food on your table among a population several times the size of what it is today, that you remember that guy on 4chan you were an asshole to.
I also have cancer and a prescription as I undergo chemo. If I wasn't wasting the last of my days trying to solve the problems of a world I won't be a part of I'd have time to grow the medicine I need. Instead I run lettuce and carb rich vegetables in an effort to make a breakthrough in cutting the time, space, resources, and waste required to grow food.
>>909652
That is fine actually. I only need it to be under 200 psi in order for my solenoid to work properly. As it drops lower it will just take more intervals to get it to the right level. I'd like to use PID and flow sensors to precisely eject the right amount of co2, but its actually beneficial that the pressure drops because it is a quick and easy way to configure low tank alerts.
Go with a medical grade "E" tank; it shold be plenty big enough and you will know what you have is actually CO2. Be aware of pin indexing. Also because of its head pressure, the psi in the tank should remain unchanged until the tank is nearly empty.
>>911128
how is this?
https://www.kegoutlet.com/20-oz-co2-tank.html
>>907674
mate you came here with a dipshit idea, don't expect to be treated like a not dipshit
>>912229
Dude came in with a pretty good experimental setup and you shit On it because you're too dumb to do any calculations. He just wanted to know about regulators and how good they are.
Nasa though, lol. I do rather suspect subterranean drug cartel grow. Op is a white kid they got chained in the basement to figure this shit out
>>912229
>Nasa lol
I dont work for them, but I'm doing private research in aeroponics and growth spectrums.
Your local welding supply can sell or lease you any size CO2 tank you might need, and fills are cheaper per volume on larger tanks. Fuck the paintball nonsense. Your regulator will protect your post-regulator plumbing. You can use a flowmeter for precise regulation at low pressures. These are popular with weldors and less expensive than a rebuild kit for name-brand units:
http://www.ebay.com/itm/HTP-Argon-CO2-Mig-Tig-Flow-meter-Regulator-Welding-Weld-/140514184508
Welding equipment uses solenoid operated gas valves. Check on welding forums for affordable units. The folks who convert Harbor Freight flux core welding machines to MIG know some part numbers but I can't be arsed to look them up.
Western Enterprises has all sorts of gas fittings and hose. Since the output of your flowmeter wil be low pressure common brass pneumatic QD chucks and nipples are fine. (We plumbed fifty welding booths with Milton chucks and nipples for out TIG students to quickly swap flowmeters. We stepped down the input pressure with another regulator upstream. Worked well and has been operating for about 8 years.)
You don't need to have a high pressure feed from your regulator or regulator/flowmeter. It's purpose is to reduce pressure and regulate flow. They are quite simple devices. They have blowoff valves in case of regulator seat failure so there is no "bomb" mode. Millions of same have been used for decades in very adverse field conditions. You can look up output pressures on manufacturers websites. If you ever need a high pressure reg check Ebay first.
I've welded for many years, ran a welding shop tool room, and rebuild my personal industrial gas regulators. It's not rocket surgery.
If you have a very large grow op, you can get CO2 supplied in the large Dewars restaurants and bars use. That kind of volume requires electrically heated regulators which are common industrial items. None of this stuff will flag you as a grower if you do it smart. The Dewars are normally delivered by truck so if you want to conceal your location, own or rent a truck with a liftgate and have your welding supply forklift it into the truck. Make fucking sure you have heavy duty tiedown straps and places to safely anchor them. You can get your Dewar on a sort of pallet with protective rails allowing easier handling.
You can also get multiple cylinders (you want VAPOR withdrawal, not liquid withdrawal) on a pallet. You can connect all at once using a brass "spider" which Western sells for about 80 bucks last I looked then connect your heated regulator to that. If you are serious you will look up the CGA (Compressed Gas Association) fittings etc and that will educate you.
Random pic of Dewars.
http://g01.s.alicdn.com/kf/HTB18DrFIXXXXXbrXpXXq6xXFXXXa/Small-Air-Ambient-Vaporizer-for-Liquid-CO2.jpg
Airgas and Praxair are common suppliers in the US. Check their websites for cylinder size and Dewar info.
Example heated CO2 regulator:
https://www.arc-zone.com/index.php?main_page=product_info&products_id=7890&gclid=CJP48oWrzckCFcGRHwod1JYPCw&zenid=clmhu62l9ls28gaj61chk7570hjbjgma
THE source for fittings and hoses. You can order those from many online suppliers, and don't neglect Ebay.
http://westernenterprises.com/catalogs/
Example gas 'noid valve:
http://www.ebay.com/itm/1-4-Electric-Solenoid-Valve-Water-Oil-Air-Gas-Welders-110-120-volt-AC-B20N-V-/301113411599
Any more CO2 questions? You can buy "green" welding gas hose cut to any length you like at your local welding supply along with fittings and reusable (avoid crimp sleeves which require a crimper and are not reusable) hose clamps there too.
>>912368
I'm definitely considering using these regulators over paintball regs. I just have to get the fittings figured out first (thanks for the links).
I'm not quite as worried anymore because I missed an important part of research; the lethal co2 limits. Working with 1200ppm is safe and I can easily set a 1500-2000ppm hard shut off and still be miles from lethal doses of carbon dioxide.
dont forget to find a way to cool your grow zone with the lights on and the exhaust off. you do realize you need to turn off the exhaust in order to get the co2 to any meaningful concentration in your grow space, right? and you want it with the lights on instead of off so the plants can transpirate, right?
whats the matter, did someone shut down overgrow or something?
>>912624
Anything after the regulator/flowmeter output can be done with hose barbs and clamps, and you can unscrew the fittings from the regulator and install whatever you fancy with that thread size. The CGA-580 fitting on the HTP flowmeter can be screwed into a "CO2 adapter" (welding regulators are used with both CO2 and argon depending on process) or the inlet nipple can be unscrewed and a CO2 nipple and crush washer installed. Check with seller about cheapest way to go as they stock all the other bits. Pic is a CGA 320 fitting and washer. CO2 crush washers are available in packs for convenience but are reusable.
This adapter connects a CO2 cylinder with CGA 320 cylinder valve to regulator/flowmeters with CGA 580 thread.
The heated regulator already has the CGA 320 fitting. Linky to CGA fitting applicability. You might want to save this if you want to play with other gases. WelderAnons should also save the info I posted since it's relevant to MIG and TIG welding and many weldors don't know the fitting nomenclature. Worth mentioning is the regulator output pressure is low enough for you to safely use common PVC household plumbing for your CO2 manifold to the plant beds. PVC won't corrode and is pleasantly cheap.
>>912651
Doh.
http://www.sisweb.com/referenc/tools/cgafitt.htm
PVC pipe part options include 1/4" NPT (learn about pipe threads, it's useful) bushings which are female. You can screw brass hose barbs into those then clamp your gas hose to the male barb. That's all hardware store stuff.
Example connection sequence:
CO2 cylinder--CGA 320 adapter to CGA 580 female---Regulator/flowmeter-- 5/8"-18 RH male (shown in HTP Ebay advert)--"green gas hose" or substitiute--hose barb with NPT male fitting of choice--PVC gas manifold to plants.
Remember CO2 is stored as a liquid so the head pressure on any regulator won't begin to drop unti the cylinder or Dewar is close to empty. Dewars gradually bleed down so are not for long term storage. Cylinders can be stored full for years.
>>912644
the primary source of heat is the 900w PAR LED light source and its accompanying 1300w PSU. I have a cylindrical enclosure for vertical farming with a tube running up the center serving as a root chamber. The PSU is at the bottom of the enclosure and is the only part that directly vents heat outwards.
My 294 3w LEDs are thermal pasted on ⅛ in aluminum strips. behind the strips is a thin copper layer with fans cooling it. I must do this to ensure that no gas escapes though the LED array atop the enclosure. Although it can do 900 watts at maximum power, I have high and low spectrum red and blue LEDs, as growth phases change the dominant spectrum will change. So I expect 600-700w max.
>>912656
So I'll likely be using ½-¼ in tubing past my regulatotand the co2 will exit 5 feet above the tank at ~70-90° F
Will it come out as a gas or a liquid at 100-200 PSI?
My guess is a gas because its too warm to be in a liquid state.
>>913274
>My guess is a gas because its too warm to be in a liquid state.
wew lawd. i mean you're technically right but you're still retarded.
>it undergoes a phase transition from gas to liquid at room temperature at an attainable pressure of approximately 60 bar (870 psi, 59 atm)
lrn2google.
>>913284
>is retarded
>quote confirms exactly what was said
u wot??
>>913320
you're right. he sounds totally informed and doesn't make it seem like pressure isnt' part of the equation at all.
