Sterlie Wort Oxygenation

[CraftBeerIndia]

Howdy PB community!

I am looking for a series of inline filters for our oxygen supply into our PHE for knockout.
We're knocking out 37 BBLS of wort and hope to achieve 10ppm O2.
I know the flowrate needs to be fine-tuned, but we're happy with 1psi for our 30min knockout using a large surface area sintered stone.

I am worried about the quality of the oxygen from the O2 tank to the stone.
I am looking at the 3-stage filter set from McMaster Carr (http://www.mcmaster.com/#air-compressor-filters/=ni88lp) for particle, oil, and bacteria down to 0.01 microns. Now at $1,000 I am seriously hoping that this is exactly what is needed, but i wanted to ask if anybody out there is using this, or if not, what are you using, and what would be less expensive alternatives...?

I am planning to use a SS304 pneumatic plug on a Tee off of the sightglass that goes into the stone. I suppose I'll also use a non-return valve so there is no wort that backflows into the O2 hose line.

Any specific products that you could recommend would be greatly appreciated.

Thanks

[Natrat]

I think this is un-necessary.

I'm not sure what oxygen you are using or where you are getting it, but most modern compressed oxygen comes from chilling and compressing air to obtain things like argon, helium, and nitrogen. Once the air is compressed, it is fractionally distilled, leaving liquid oxygen behind, which is then put into tanks. If it is "medical grade" oxygen (which is the lowest grade), then it may have been produced by using a zeolite membrane during nitrogen production...and that would exclude any infectious pathogens or contaminants.

However, I struggle to think of a pathogen that can survive a pressurized O2 atmosphere...talk about an oxidizer! No infectious pathogens can survive any part of that process. In fact, if you are over 8 psi gauge pressure, I think anything in your hoses will be dead, as well. But cleaning them can't hurt.

If you are concerned about things like grease, don't be. Because oxygen is such an...oxidizer...things like hydrocarbons burn in pure oxygen to become elevated levels of CO. Because of this fire hazard, oxygen service containers and equipment are specially cleaned to be free of any hydrocarbons or other chemicals that may burn in the presence of higher partial pressures of oxygen. Most of the lubricants used in oxygen regulators are either food safe, or so toxic that they aren't used in your run-of-the-mill regulator on a brewery O2 tank.

Filtering your oxygen is up to you, but the material you filter with may induce an oxygen fire (or many little, undetectable fires) that could be dangerous, or at the very least, prohibitively expensive. When oxygen is "contaminated, " it generally means it has carbon monoxide in it. If you decide, ultimately, that you want to filter it, make sure you do so at pressures BELOW 15 psi gauge pressure/30 psi absolute. And if you decide to hardpipe any of it, make sure your hardpipe installation is done by an OSHA, NASA, or ASTM certified hp oxygen technician.

Just a reminder, if you want oxygen that is better than "medical" grade, ask for aviation grade oxygen or welder's grade oxygen. They are the purest, unless you spring for research or lab grade oxygen.

Good luck
Nat

[CraftBeerIndia]

great!

Thanks for your fantastic input Natrat! I aspire to having that type of knowledge.

When i stepped into this brewery there was some liquid in the O2 line which was oxygenating my first batch.
Didn't have any problems, but I was concerned about making sure the O2 was sterile.
Planning on using a check valve to prevent back flow of wort into the line, obviously.
I was wondering if the liquid in the line could also be condensation from the O2 in which case, do you think a line drier or moisture separator would be needed. I think the "grade" of oxygen is probably very acceptable regardless (medical, aviation, etc...)

Any other comments (?) and thanks again for the input

I think this is un-necessary.

I'm not sure what oxygen you are using or where you are getting it, but most modern compressed oxygen comes from chilling and compressing air to obtain things like argon, helium, and nitrogen. Once the air is compressed, it is fractionally distilled, leaving liquid oxygen behind, which is then put into tanks. If it is "medical grade" oxygen (which is the lowest grade), then it may have been produced by using a zeolite membrane during nitrogen production...and that would exclude any infectious pathogens or contaminants.

However, I struggle to think of a pathogen that can survive a pressurized O2 atmosphere...talk about an oxidizer! No infectious pathogens can survive any part of that process. In fact, if you are over 8 psi gauge pressure, I think anything in your hoses will be dead, as well. But cleaning them can't hurt.

If you are concerned about things like grease, don't be. Because oxygen is such an...oxidizer...things like hydrocarbons burn in pure oxygen to become elevated levels of CO. Because of this fire hazard, oxygen service containers and equipment are specially cleaned to be free of any hydrocarbons or other chemicals that may burn in the presence of higher partial pressures of oxygen. Most of the lubricants used in oxygen regulators are either food safe, or so toxic that they aren't used in your run-of-the-mill regulator on a brewery O2 tank.

Filtering your oxygen is up to you, but the material you filter with may induce an oxygen fire (or many little, undetectable fires) that could be dangerous, or at the very least, prohibitively expensive. When oxygen is "contaminated, " it generally means it has carbon monoxide in it. If you decide, ultimately, that you want to filter it, make sure you do so at pressures BELOW 15 psi gauge pressure/30 psi absolute. And if you decide to hardpipe any of it, make sure your hardpipe installation is done by an OSHA, NASA, or ASTM certified hp oxygen technician.

Just a reminder, if you want oxygen that is better than "medical" grade, ask for aviation grade oxygen or welder's grade oxygen. They are the purest, unless you spring for research or lab grade oxygen.

Good luck
Nat

[Natrat]

Stick a stainless steel check valve just before your O2 stone. That will prevent wort or cleaning liquid from going up the line. The other option is to maintain gas pressure on the line, or remove the stone for cleaning, which I recommend anyway. If you take the entire oxygenation stone out of the inline assembly, and soak it and dry it, you'll be golden.

Many quick release fittings have check valves in them, and that might be a good way to attach your O2 feed

Brass will work, but your cleaning chemicals will corrode the seat and the check valve will eventually fail. Having said that, you can buy a LOT of brass check valves for the price of one 316L check valve.

But I agree that any liquid in the O2 line that collects after pressure has been released is a potential contamination issue.

Nat

[Natrat]

Also, there is negligible water in the O2 you buy. Medical grade oxygen in the US has no dewpoint specifications, but aviation grade specifies -80C or lower. There is no reason for most cryogenic gas companies to make different grades of oxygen...they just make one to the best spec they can achieve and sell it at different grade points. When you buy aviation oxygen, it's probably the same spec as their welding grade.

Medical grade is sometimes made with a zeolite membrane, and can have a bit more water in it (which is nice if you're breathing it...less "cottonmouth") but those vendors will ONLY sell that grade.

Research grade oxygen has almost no water, but is very expensive....