inline o2 injector

I've been wanting to do this for awhile and if I would have realized how cheap and easy it was I would have done it sooner. My injector is made from brass 1/2"FPT Tee, 1/4 compression x 1/2MPT, 3/8 compression x 1/2MPT, 5/8 compression x 1/2MPT and a .5 micron aeration stone. It all screws together and apart for easy cleaning. I had to drill out the 1/4 for the air line because it was not a bore through design and I replaced the 3/8 brass ferule with plastic so it could be removed from the chiller. The 5/8 connector is for 1/2" ID hose to go to the fermenter. I used a larger hose here so it might defoam a little on the way to the fermenter. It took longer to find the parts than to put it together. Cost was $16 plus the stone. It works with CFC's


I want to find an o2 flowmeter that will display less than the 1-15LPM of standard medical flowmeters but until I do will just have to guess.

Here is a suggestion, look for a Dwyer VFA-1 acrylic flow meter and set flow rate to .5 SCFH and use a 3 minute duration for a 6 gallon batch size. The flow and duration numbers were developed over 3 years with average OG of 1.055 and using ready to pitch vials by white labs and wyeast without starters for repeatability. Higher flows and longer durations greatly increased attenuation unless so much O2 was used that there was foam instead of absorption, lag times were usually greater than 12 hours with FG numbers at spec for yeast strain used at flow and durations above.

I like! (10 chars)

Not sure how easy it would be to add, but a site tube downstream of the injector would be nice so you can monitor the bubbles. I know of one brewery that didn't have one (yet), there was a problem with their o2 system and ended up with 15bbl of unoxygenated wort.

Of course in a homebrew setting its a bit easier to know its working, but it'd be a nice toy to have.

Props on the idea, I've been thinking about doing something similar for a while now

I figured it to be easier to use a flow meter on the O2 line. I'm currently researching what O2 flow to run at a given wort flow rate of 2.5LPM (equates to roughly 12.5 gallons in 20 min)to end up with 12-20 ppm of dissolved O2 @ 70F. Then I will just set the O2 flow meter to the desired rate and the wort into the fermenter should have the optimum O2 levels with no O2 wasted. I'm using the above wort flow rate as my standard because that is what my chiller flows in single pass chilling. I will post results eventually, since I'm having trouble with all the variables and math it might take awhile.

Thanks Klaude, after some searching I think I found some that will work and only $30.
John Beere, thanks, I always like the KISS principle, but am still hoping to someday integrate the DeepSix automation into my equipment.

beerthirty said:

Thanks Klaude, after some searching I think I found some that will work and only $30.

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so what did you end up going with? links? pics? any more info??

tjferris said:

so what did you end up going with? links? pics? any more info??

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yeah...
no teasing us, saying you found a new toy, and not telling us where we can get one ourselves...

I have fallen flat on my face trying to do the math with temp corrections and converting ppm to LPM but here is the flow meters I have found. General Laboratory Supply: Products
here is a page of formulas that I was trying to work with
Correction Formulae & Sizing
the flowmeters only have a 150* temp range but since I was planning on installing at the output of my chiller I don't see temp as a problem for the liquid meters. They also have the gas meters to measure the O2 rate but since the math failed I have been winging it using a clear output hose so I can see the bubbles. I'm still looking for a hi temp flowmeter to use on the output of the mash tun and HLT for fly sparging. Metering got put on the back burner since I switched to keggles from pots and still calibrating the new rig. Anyone who wants to take a stab at figuring out O2 flow levels please have at it.

very clever, beerthirty.

you are almost there, build one like this :

mrbowenz said:

you are almost there, build one like this :

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Very nice. I'm going to finally build one like beerthirty's as soon as I find the pieces. Lowes didn't have them when I looked yesterday. I'll check ace tomorrow, and I'm sure they will have them.

I think I'm going to use a cross instead of a T and put a thermometer on the other side

very cool, looks like I have yet another toy to build into my brewery. :rockin:

mrbowenz;

What are the dimensions of your glass tube window and where did you get it?
I have a medical O2 flowmeter, .5 to 15 LPM but would like to see the amount of bubbles or foam coming off the stone thru a glass tube. As far as wasting O2 a couple LPM off a 260 cu/ft oxygen bottle would not even be detectable or a concern.
Thanks.......

BrewBeemer said:

mrbowenz;

What are the dimensions of your glass tube window and where did you get it?
I have a medical O2 flowmeter, .5 to 15 LPM but would like to see the amount of bubbles or foam coming off the stone thru a glass tube. As far as wasting O2 a couple LPM off a 260 cu/ft oxygen bottle would not even be detectable or a concern.
Thanks.......

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Believe it or not, it's a glass slide ( guitar ) , it's made of pyrex and works great I think it's 2 3/4" by 1" dia. ID

mrbowenz said:

Believe it or not, it's a glass slide ( guitar ) , it's made of pyrex and works great I think it's 2 3/4" by 1" dia. ID

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I located pyrex ring material in size 14 that has 1.400" ID, it's available up to size 17. This would work great plus allow room to center the stone in the pyrex window to watch the bubbles coming directly off the stone.
Use stainless Tig wire to center the stone in the pyrex tube, machine brass end caps with a square ring groove for sealing against the glass with NPT in the center of the end flanges. Drill and tap for four stainless screws to hold it all together. Off the stone's nipple extend it past the Tee for a compression fitting seal. I have in stock 10' x 4.125" x 7/16" thick brass stock that I can hole saw disks out then machine and tap on the lathe.

Another item added to the things to make list.

Update due to a few questions that I received. The airstone barb had to be ground down a bit to allow the 1/4 OD tube to be stretched over it. while handling the stone I slid a ballon over it to keep skin oils from clogging the stone.
While cleaning it last time I realized the stone had come off the tubing. I'm sure this was caused by pumping boiling wort through the injector. This time I used SS lock wire to secure it. If I were to remake this I would use silicone tubing instead of the vinyl crap.

FSR402 said:

very cool, looks like I have yet another toy to build into my brewery. :rockin:

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It's not a toy it's a tool so it must be used as a Tax Write Off correct?

mrbowenz said:

you are almost there, build one like this :

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So mrbowenz,

Do you have more details on your build? Can we see it in action (photos?).

Has it been a pain to keep clean?

Sorry mate, a few months ago I changed my whole system over to tri-clover stuff, I now have a replacement "tee" with a stone in it from St. Pat’s, and a sight glass in another area of the loop. I used this one for about 25 batches, and it worked great, but it's been tossed in a box of brass fittings and since been cannibalized for a keg cleaner setup.