Copper brazed stainless heat exchanger question

[jgmillr1]

Sorry if this is a dumb and obvious question but I figured I'd rather get confirmation and than copper poisoning. Spent the last hour unsuccessfully googling for the answer. I called the manufacturer but was not able to get through to anyone.

I bought a 30-plate wort 304 stainless heat exchanger that is brazed together with copper. You can see the copper brazing between stainless plates on the outside of the exchanger but the inside appears to be pure stainless. Though, it is difficult to look clearly into the 1/2" ports.

Can anyone confirm that there is no exposed copper on the interior of these stainless heat exchangers? I realize it makes sense that there should be no copper in contact with the liquid, otherwise there is no point in having it be made with stainless.

As an aside, I am using this to chill wine and since it is much more acidic than beer, it should not come in contact with copper.

Thanks in advance.

 

[beermanpete]

I doubt the copper in NOT exposed to the interior. How much exposure depends on how well the heat exchanger is made. You can get a nickel brazed heat exchanger but they likely cost more.

 

[IslandLizard]

There is copper brazing in the interior. Plate chillers like those are not designed to leave acidic (or even alkaline) fluids inside for lengths of time.

I doubt much copper will be released during 15-45 minutes of chilling a kettle of hot beer wort. Been using one for 9 years and it still hasn't fallen apart.
In that application, after use, rinse out well, and drain thoroughly. Treat with sanitizer, drain well again, and shake out, or bake in oven at [Edit] 250-450F for an hour or 2 (with the pizza or bread) to sanitize.

 

[jgmillr1]

Thanks for the tips on cleaning it and the nickel brazing option. Once I got into better light, the copper was clearly visible inside the heat exchanger. So, I returned the copper unit and ordered a nickel-brazed 316 stainless one from Duda.

 

[IslandLizard]

Ah, good to hear you found one.

But now you got me curious, how exactly are you planning to use this chiller?
For example, many brewers use a cold plate or coils to chill their beer, mainly when dispensing on location.

On the cleaning points there are a lot of ways to do it. We typically recirculate boiling wort through the chiller for 5-10 minutes to sanitize it before we start chilling.

 

[jgmillr1]

The whole project is to bottle sparkling wine more efficiently. I planning on using the heat exchanger to cool the wine from a room temperature tank to a carbonator on it's way to a counter pressure bottle filler. It needs to be cold to reach the 5+ volumes of CO2 necessary for wine at a reasonable pressure. The flow rate of the wine is only up to 1 gal per minute, so that allows me cool it inline rather than having to cool and entire tank down. The chiller is a 1.5ton glycol unit which should be more than sufficient.

 

[IslandLizard]

Wow, that's a much more advanced application than I imagined!

Must be quite some operation. How many gallons do you process like that?

 

[jgmillr1]

The system should be capable of bottling a maximum of 30 gallons of sparkling wine per hour. I'm figuring we'll produce upwards of 1200 bottles this year.

 

[mabrungard]

For wort handling, exposed copper poses NO danger to the wort or the drinker. Yeast metabolizes and sequesters virtually all free copper ions. The State of California worried about this same thing and did a bunch of testing and finally confirmed the result I mention. However, for the application that you're contemplating, its pretty clear that the acidic wine would place a quantity of copper into solution and there wouldn't be any opportunity for yeast to do their cleansing.

 

[jgmillr1]

Just closing out the thread I'm case someone searches it later.

I got some John Guest 3/8" flare fittings (didn't know they made those!) and hooked them up to the input/ouputs to the carbonator.

The nickel brazed 316 stainless heat exchanger is hooked up with 1/2" brass hydraulic quick disconnects for the glycol chilling. Finally ready to roll.