CO2 Filtration

[Elevation_Beer]

Hey everyone,

I am curious if most breweries are filtering their bulk CO2 before it enters the building. If so, what type of filter do you use?

Thanks!

Christian
Elevation Beer Company

[TGTimm]

We don't filter our CO2. I'm not sure what kinds of noxious critters can survive in pure CO2 @ 300+ psi, but I don't think there are many.

We do have a sediment trap--a T with a long downward-pointing dead leg--to trap any bits that may escape from the tanks. This is standard practice (code, actually) for fuel gas plumbing.

[Starcat]

Same Question

We had the main feed line cracked open one day and noticed a blackening on the interior of the hose.
After speaking with the C02 guy, he said usually its either caused by assembly lube in the regulators, or " backflow."
Backflow seems to be a reality when there are a number of rookies in lengthy training in the plant. The next challenge being to get them to look at the large readout gauge on the wall.
He did allow that sometimes, rarely there will be incidences of " oil " in the bottom of the tanks, but when that happens it is noticed quickly and the impression I got was that it does not migrate out. There was seemingly a possibly need for a filter which was exactly what I asked him, its apparently not being done.

[BrewMage22]

CO2 and other gas filters

Heyo,

CO2, O2, N2, and compressed air can all be easily filtered. Most breweries I've worked in don't filter these gases for the same logic as previously stated, that little or nothing can grow in a tank of high pressure compressed gas. The same logic is also what makes the filtration so easy, in that there is little to no loading of the filters because the gas is so clean. Most breweries I've worked in and seen do not filter their gases, beyond basic air driers/desiccants, etc. The problem of course is when failure occurs. Any 15 degree temperature differential can cause condensation in a hose. If that hose opening is exposed, say when changing a fitting, it allows your brewery air to enter the hose with everything in that brewery air, including moisture, dust, mold spores, bacteria, etc. With no regular cleaning and no filter it is possible to have colonies build up.

Pall Filter Corp makes a line of gas filters that are inexpensive and made to last for a year or more. In my brewery I have one on the main CO2, O2, and Compressed Air lines, with clamp, pneumatic, or flare connections to my tanks, oxygenation setup, keg washer, etc. This way I can clean or replace the sending lines and ensure that the main is protected.

http://www.pall.com/main/biopharmaceuticals/product.page?id=32890

I think I paid about $50-60 per capsule, which seems like cheap and worthwhile insurance to me.

SD

[Elevation_Beer]

Thank you all for the replies!

Anyone else willing to chime in?

Thanks,

Christian

[TGTimm]

There is always a chance for contaminants to enter your gas lines, so filtration isn't a stupid idea. I'm still not too worried about anything surviving in the lines before the primary regulator, and not too worried about the main trunks. The biggest risk of contamination, 'though, is at the delivery end. As someone mentioned above, a slight change in temperature--or just plain ol' diffusion--can result in ambient air and the bugs it carries entering your lines--after the filter. To prevent this, or at least minimize the risk, I've been using these QDs: http://emurdock.com/3003ssfosterquic...ectsocket.aspx Like the QD on a compressor air line, they shut off when disconnected, preventing unwanted gasses and critters from sneaking into the lines.

Good quality check valves also help keep crud--especially beer--out of the lines. I've rebuilt too many regulators because someone forgot to remove the drop line from the fermenter/bright tank carb stone before turning the regulator down to below the pressure in the tank.

Since the CO2 delivery drop lines are post-point-of-use regulator, the pressure is very low in these lines (0-2 bar, max) and I can easily see microbes surviving in them.

[cpelz]

Hey Timm-

Do you have a source for good quality check valves? I did some cursory poking around for alternatives to the draft line ones but didn't turn up anything.

[TGTimm]

Quality check valves? No, but I have found some that usually work.

We use Norgren in-line check valves. They're plastic with a John Guest style push-fit on each end. The one I have in hand is model # T51Y0004, with 1/4" OD fittings. They're available in various sizes. We source them from Kaman Ind. These work about as well as anything I've found. Obviously the plastic housing can't handle much heat, so low-temp cleaning and sanitizing is needed.

The absolute best functioning check valves I've found are the ones used in our Zahm & Nagel stone housings. These are the little rubber nipple style, also found in some draft equipment. Sure, the little rubber bits wear out pretty quickly, but they're cheap and easy to replace. If I could find the proper SS housings for using them in-line, I'd be very happy.

[brundage]

We started putting SS check valves in all our CO2 stones. I think they're from McMaster. Not cheap, but not exactly expensive, especially after tracking two bad batches to the CO2 feed (beer backed up in the line). Put some thought about how you will clean your gas lines before running a system.