DIY Chilled Conical/Keg Fermenter

[CenCalWorthog]

Damn, that looks great... you have a lot of skill and a lot of time!

 

[Islandboy85]

Did you ever get pictures of the project completed Yuri?

 

[Yuri_Rage]

It's not done yet. I powder coated it tonight. Like a dummy, I used some flammable tape to mask a portion of the top, then set it in the oven upside down, very close to the heating elements. As a result, there's some smoke and ash in the coating that make it look...artistic?

Fortunately, it's just cosmetic damage. The coating is intact, and I really only needed to coat the legs since they're the only parts that aren't stainless. Also, the entire thing will likely be covered with insulation, so it's not a big deal. Still, I feel dumb.

I hope to do some more tomorrow so you can begin to see the method to my madness.

 

[Islandboy85]

Just turn it a little bit, put it in the corner, and no one will know about the little carbon streak you've got there

 

[LooyvilleLarry]

You have an oven that is big enough to put that thing in? Wow, that ups the tool ante a bit.

 

[ScubaSteve]

So is the color going to change from salmon pink to something more awesome?

 

[Sawdustguy]

Yuri, did you really powder coat it at home? Man, I wish I had your toys and knew how to use them. This motivates me to take a TIG welding class.

 

[bendavanza]

I think that's a copper color like he used in his brewery. Probably just did not photograph well.

 

[tomije87]

Looks great! How tall does it measure?

 

[Yuri_Rage]

It's copper colored. If anything, the color is a bit too brown for copper. It definitely doesn't look pink (neither in real life nor on my monitor).

Yes, I powder coated it at home in a self-built oven that is 3'x3'x5'. See my brew hut thread for some DIY powder coating that turned out well. This was my first major powder coating blunder in several years! The other side has an even bigger scar. Oops.

The fermenter is 44" tall.

 

[Yuri_Rage]

Ok, here's what I have so far:

It's the guts from my kegerator brazed onto a measured length of copper tubing. There are no leaks, and it seems to get quite cold. However, I think I massively overcharged it with a careless bit of impatience. More to come for sure.

 

[arturo7]

You are running a refrigerant through the copper?

 

[Yuri_Rage]

Yes - R134, per the kegerator's design specs.

 

[arturo7]

Have you had any training on refrigeration systems? Isn't there specialized gear involved with charging the system?

Just want to see if this is feasible for an average Joe DIY'er like me.

 

[Yuri_Rage]

I've had no formal training. I know how to braze, and I understand refrigeration concepts. Technically, you should have a licensed repair facility evacuate and charge the system. WalMart sells R134. That's all I have to say about that.

 

[bendavanza]

Yuri
Did you weld from the outside and if so, how did you go about making a smooth surface inside? There must be a plan for a thermowell somewhere? I know you're not finished and we appreciate the incremental updates.

 

[Yuri_Rage]

I purged the entire keg with argon during welding.

A temp sensor will be incorporated into the lid.

 

[RonRock]

That poor, poor Kegerator. So brave to sacrifice itself for such a noble cause.

You're the man Yuri!

 

[CodeRage]

Hey Yuri, when you modified the refrigeration system what was your process? More often than not they crimp the service ports, did you find some kind of hi/lo attachments for the R134a? Did you pull a vacuum on the system prior to charging?

If it is overcharged that compressor isn't going to like it

 

[humann_brewing]

That is saaaweeet!

 

[lamarguy]

More often than not they crimp the service ports, did you find some kind of hi/lo attachments for the R134a?

You need to install an access valve for no-serviceable A/C systems. They make piercing (solderless) and solder type access valves. From the picture, it looks like Yuri soldered in a valve.

 

[Cpt_Kirks]

Have you had any training on refrigeration systems? Isn't there specialized gear involved with charging the system?

Just want to see if this is feasible for an average Joe DIY'er like me.

Well, not to be mean (maybe a little), but about any monkey can do refrigeration work. There is not that much too it. I have known drooling idiots who have made a very good living doing it.

That being said,

THIS HAS TO BE THE COOLEST PROJECT ON THE SITE!!!

:rockin:

 

[CodeRage]

You need to install an access valve for no-serviceable A/C systems. They make piercing (solderless) and solder type access valves. From the picture, it looks like Yuri soldered in a valve.

Sweet! Thanks, Something like that may be in my future

 

[klyph]

Way cool project. I love when the old-but-good stuff gets bumped so new guys like me can enjoy it.

 

[mmurray]

FYI, that is called a Schrader Valve and usually on the compressor like Yuri has used a 1/4" valve will work fine.

Also, you can usually find cheap A/C evac pumps on ebay. I bought mine for $9.99 and all you do is hook it to an air compressor and it will pull a vaccum in around 10 minutes... Then let it sit for another 10 minutes and if your gauges haven't moved then you are good as gold.

Yuri, I would suggest spending the $10 and evacuating the system... the moisture and high head pressures will definitly shorten the life of that compressor... and those compressors (provided all the plumbing is the same as original) only use 5oz. of R134. What I do is place a full can (hooded to my gagues) on a scale and start the fill... once 5 oz. are in I close the valve and it's done!

Good luck and awesome build!!!

 

[mmurray]

In fact here is one from Harbor Freight for $16... It's simple and low buck... handy for the occasional job around the house. You can use this on R134a and R22 systems...
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96677&xcamp=google&utm_source=googlebase&utm_medium=cpc&zmam=33951326&zmas=12&zmac=112&zmap=96677

 

[WortMonger]

Wow, just wow! I read this thread every time I see updates since its inception. I was told this wouldn't work... so I am glad I am seeing it done Proof pudding anyone? Yuri is Da-Man!

 

[Yuri_Rage]

Thanks for all the replies. I hope to have some test data soon.

I bought the 1/4" Schrader service fitting at McMaster. Everything is brazed with StaySilv 15 - with good, clean copper, no flux is required. I've heard a bunch about the evils of soldering HVAC lines - all sorts of horror stories concerning acid flux, weak joints, deterioration, etc. So, I purged the system with argon (nitrogen also works) and brazed it rather than using solder.

I pulled a vacuum with a hand operated vacuum pump. It took a while, but I think it was pretty effective. The kegerator's placard called for 2.1 oz, and I kept the overall system volume pretty close to the same. However, I didn't have fine enough flow control over the R134, and I quickly overcharged the crap out of it. I will purge and carefully recharge before running the compressor for any length of time.

 

[CodeRage]

I pulled a vacuum with a hand operated vacuum pump. It took a while, but I think it was pretty effective. The kegerator's placard called for 2.1 oz, and I kept the overall system volume pretty close to the same. However, I didn't have fine enough flow control over the R134, and I quickly overcharged the crap out of it. I will purge and carefully recharge before running the compressor for any length of time.

Yeah, I bet I know where that hand pump came from......








the brake bleeder right?

Again, that's just too cool. Thanks for filling in the gaps!

 

[WortMonger]

Well, all I can say is mine would be wrapped in Reflectix and shot with truck bed liner, lol. That is one sexy beast Yuri! Everyone I talked to said it would run constantly and not work, so once again thanks for actually doing it. I cannot wait to see how this "Beer-Bot" turns out. That's what I think when I see it, an R2 unit with a big.. uh-hum.. package. Watch out for Sand People!

 

[Yuri_Rage]

After a careful recharge to within 0.1 oz of the original spec, I think I'm on to something. I'm seeing coolant line temperatures around 15° F. Guess I need some insulation now!

 

[klyph]

Wicked bad. I need to tear the guts out of a mini fridge for a fermentation chamber.

 

[RonRock]

Wouldn't your refrigerant charge amount change with the copper line opposed to the original coil? Unless the copper line had the same volume as the original. I can't tell from the picture, but I'm sure you don't want the line frozen back to the compressor, it will freeze the valves. Without knowing for sure how much charge this should take, You could go by your gage set and temps. Or I'd think even better would be a sight glass in-line. I think you can get them at an AC supply. That will let you see how the system is working. Charge, air, moister in system.
As far as the vacuum, you should leave the system under vacuum for at least 1/2 hour and then close valves to check for system leaks and cook out any moisture. May not be exactly to HVAC procedure specs. But a start in the direction.
You probably already know all this, but if not maybe helpful.

 

[ikonis]

Pure awesomeness... makes me wish I could weld and/or powdercoat!

 

[Yuri_Rage]

Wouldn't your refrigerant charge amount change with the copper line opposed to the original coil?

That's why I put a bit of effort into making sure that the new DIY line has nearly the same volume as the old one.

 

[RonRock]

Yeah, I should have edited. I went back a couple pages and read that after post. Still might help someone, looks like others are considering your plan.

 

[Yuri_Rage]

I'm finding that charging is a bit finicky. The charge volume is so low that a very slight change in R134 by weight (0.1 oz) makes a significant enough change in system pressure to result in a big difference in performance. I'm pretty sure I have things ironed out now, and the line temperature is a bit higher as a result - around 30° F.

I put a bit of bubble wrap around the fermenter and directed a fan across the condenser to dissipate the heat produced. With over 10 gallons of water in the fermenter and scant insulation, I'm not sure that I'll see a measurable temperature change before I go to bed, but it's worth a try. Eventually, I plan on using some foam insulation wrap to make a cylinder that will fit over the entire keg.

 

[CodeRage]

Yuri, I'm sure you have considered this but...
What about flattening out the evaporator coil a bit and brazing/silver solder it to the fermenter wall for better thermal transfer? It looks to me like it is pulling most of the heat out of the air. The frozen condensation on the coils is going to make it that much more inefficient. If they were bonded to the fermenter wall you may not have this problem.

 

[Yuri_Rage]

Yup, I'm definitely considering doing a bit of hammer forming and further brazing. I never intended those zip ties to be permanent. I had to prove I could make it work, first!

 

[bhatchable]

so how did the water test work out?