Proper Cleaning of a Duda Diesel PHE

[kotti270]

Hey everybody,

I have a DD B3-23A plate heat exchanger and I was experimenting with different chemicals to clean it without corroding the copper brazing inside.

I've tried 1% caustic as well as PBW recirculating backwards through it at 150F and they both clean just fine. The only drawback is that the cleaning solution after about 10 min turns a slight blueish green color. I'm thinking that it is some sort of chemical reaction between the chemicals and the copper. I am afraid that I am corroding the copper inside which will eventually cause cooling water to enter the wort side.

I am searching for any input on different chemicals that would be safe to clean with, that would not "corrode/disolve" the copper.

Does anybody else have the same problem? Any input from a chemist would be awesome!

Cheers!!

 

[mdr5322]

I just run hot water through it til i see the water come out clear and i put it in star san. haven't had a problem yet and have cooled more than 20 beers with my duda diesel plate chiller. no build really happens if you clean it right away. These plate chillers are food grade products so they're designed to not stick much like non stick pans which like them should be washed with a soft towl to not scratch the teflon later bringing stickage of food. Get what I'm saying? Sanitation is definately a thing to worry about and keep in mind at all times but some people really do go overboard sometimes with it. Just rinse the thing as soon as you're done with it. happy brewing!

 

[mikescooling]

After use I flush with hot water front to back, back to front. And before use I pressure cook it for 15min.

 

[day_trippr]

[...]These plate chillers are food grade products[...]

While I'm the happy owner of a Duda long 40, I'm almost certain that the above is not actually true...

Cheers!

 

[kotti270]

http://www.homebrewersassociation.org/forum/index.php?topic=5733.0


I'm thinking the cleaning solution is taking the oxide off the copper thus taking a thin layer off every time I clean it. Does that make sense?

Thanks,

 

[day_trippr]

Clearly, it's removing copper in some form. And iirc, there are words on Duda's site about being cautious with caustics...

Cheers!

 

[mrklueber]

I have used the Duda Diesel plate for all of three brews now. I flush it with 180F water in both directions immediately after chilling the wort. After the last brew, we ran hot PBW through it and then flushed it again with 180F water. I also run 180F water through it right before using it to cool the wort. So far, no problems.

 

[mpcluever]

I have a dudadiesel chiller and I didn't recall seeing anything about caustic. It DOES warn about CORROSIVE fluids, but sodium hydroxide that I use doesn't react with stainless or copper. http://www.dudadiesel.com/heat_exchangers.php. I rinse with water, then recirculate 180° PBW, then water, then 180° sodium hydroxide, then water. Seems really effective. With just PBW, it turns a slight shade of green even after 3-4 cycles from hop debris.

Regarding just using sanitizer, I've seen what happens in a counterflow chiller when you only rinse with water, then StarSan. NOT anything I want anywhere close to something I'm drinking. Awful. StarSan is not a cleaner and will not remove anything. Sure it will kill the top layer of whatever gunk you have in there, but that's not sufficient for any long term cleaning system.

 

[kotti270]

Thanks for the input mpcluever!

Here's a quick link to check out "Metallurgy for Homebrewers ".
http://www.homebrewersassociation.org/forum/index.php?topic=5733.0

As for the hop debris turning the cleaning solution green, It's a possibility, but I usually back flush with 190F water until discharge is clear. Then I recirculate with at pump backwards with chemicals and then it turns green/blue, but it's not a "natural" green/blue.... it looks like copper oxide dissolved in the solution.

+1, never use starsan to clean with. The best way to sanitize your PHE is to recirculate 200F brewing liquor through it for 30 min to kill everything with heat.

 

[mpcluever]

I'm pretty sure that the green color was hop debris. Small chunks would continue to come out with each cycle. Also, from using an immersion chiller before the plate, wort takes the oxide off fairly well leaving the chiller bright and shiny.

 

[mdr5322]

everyone here is amazingly knowledgable about metals and cleaners and the corrosive aspects of using cleaners on metals. I should have paid more attention in science class I guess. my comment on back flushing til water comes out clear then using starsan was just a suggestion and not meant to be taken as law. anyway, good discussion and good feedback from everyone I love reading it. so in my defense i'll continue doing what im doing cuz it works for me and have never had any issues or lost batches or any weird side effects w the star san since I use it on everything else including the proffessional kitchen I work in. I know its not a cleaner and I dont use it as such. but what common sense tells me is that build up happens when you leave something uncleaned sit out and dry or it gets burned on. the way I see things is hop trub amount is minimal until you get to the bottom of your kettle at which point I stop collecting so no "build up" issues there and from my 10 years of being a chef my experiences w working with sugars such as glucose, the sugar we so desperately desire in our worts is that it caramelizes at 320 F in the absence of WATER which im sure everyone should be familar at this point is what makes up the majority of our beer. Again, no build or burnt stuff for me to worry about. Im no scientist when it comes to what chemicals react to what metals so I give everyone credit for knowing there stuff, kudos! I use soap, hot water, then sanitize. I figure I dont give enough time for build up to happen, so yes, what I do works and makes sense. thank you all let the discussion begin!

 

[day_trippr]

I have a dudadiesel chiller and I didn't recall seeing anything about caustic. It DOES warn about CORROSIVE fluids[...]

Fwiw, you're right, they used corrosives. But caustics are a subset of corrosives, so I'd still consider that a caution, and avoid anything that produces blue-green effluent except for extreme needs...

Cheers!

 

[mpcluever]

Sure, caustics are a corrosive, but not to the chiller itself...