DIY cleanable plate chiller for $30?

Hi Everyone - this is my first post on this board... hoping to make a fine impression and to run a few of my DIY ideas by the experts

Lately I've been thinking about building a plate chiller that can be easily disassembled, cleaned, and then reassembled in a a matter of minutes. It has taken me a little while to grasp exactly how a plate chiller works, but now that I have done my homework, I believe that a DIY build is not only possible, but would be really cheap too.

I have never held a plate chiller like the shirron in my hands, but I gather that they are a) built from small gauge stainless steel b) brazed together c) and have convoluted plates to help break apart laminar flow.

I propose to build a chiller having a) alternating aluminum plates and b) sandwiched rubber gaskets controlling the fluid path. The plates would all be sandwiched between two large gauge plates (could be steel), which are wider than the chilling plates. Bolts connecting the top and bottom plate would hold the whole thing together. The top plate would need to be a material making it easy to attach fittings to (i.e. inlet and outlet hoses), or would have to be thick enough to accommodate NPT threads tapped into holes drilled through the material.

I was inspired by the larger HVAC plate heat exchangers, which use stainless steel plates and rubber o-ring type gaskets to seal the gaps between plates.

Sheet aluminum is inexpensive and malleable (easily to convolute). Sheets of rubber, cork, and other gasket material is also available for cheap as well.

Have any of you tried to build something similar to what I am suggesting? Can you see any stumbling blocks that I might encounter?

I don't have much in the way of a workshop...a hand drill and bits, a dremel, etc. Is it difficult to drill and cut thin aluminum sheeting?

Cheers

Thin aluminum is easy to cut (think gutters). What you'll probably run into is that getting a very clean, straight edge is going to be next to impossible with tin snips. This will require a large shear. you will need this smooth edge in order to get an adequate seal.

Another thing, you will want to use teflon gaskets most likely. Rubber at high temps isn't really your friend. Silicone wold work, but in order to get an adequate seal over such a large surface (unless your plates are VERY flat) you will want something that won't squeeze out under compression, and I suspect that silicone would do just that, but I may be wrong.

Also, you will want to use a very heavy gauge metal for the front and back plates I suspect, or else use some angle stock around the edges that is very flat. Even if you put a lot of bolts in it getting even clamping pressure on your gaskets is going to be difficult without eliminating as much flex as possible from these plates.

As far as the fluid connections, I would look into soldering them onto the faces of the plates with silver solder. Look up the keg tool, then use that type of solder joint with a 1/2" coupler and screw the appropriate fitting into it.

Finally, convoluting the plates so they all match and still have nice flat edges will be tricky. If they don't match you run the risk of pinching them, and once again without the flat edges clamping will be tough.

I'm not trying to discourage you, and sorry if I sounded like a negative Nancy. I'm behind you 100% on this, so keep the ideas flowing, and keep me posted on how it proceeds. I think that this is a great idea, as long as you can source the materials cheap enough.

Light gauge aluminum 14 to 16 can easily be cut if you get accesss to a table saw with a sharp fine tooth carbide blade with some wax stick lube.
Your idea sounds good able to take apart and clean but sealing up
and leak proof may be a challenge. I would make it out of copper.

Has anyone attempted to make their own like the op was thinking?

Sabco. $789. https://brewmagic.com/products/plate-pro-sanitary-wort-chiller/

Might offer some inspiration/guidance ...

We've got two paraflow heat exchangers, one for the 1,300L and one for the 2,600L kits. Apart from size they look and function exactly like the sabco one linked. They CANNOT be disassembled in minutes to clean and you've got to keep the tension very high (but even) to prevent leaks. Getting them back together is a dark art and you'll be tweaking them with a spanner for a week afterwards until it is right again. If you've ever been so bold as to strip one down you'll be in for a treat as they are absolutely filthy. We run 500micro filters before them, but even so they are absolutely filthy things.

We flush them with hot water both ways after each brew and they get a couple of hours of clean in place using chlorinated caustic at 2.5% after all brewing is done for the day with periodic recirculated hot caustic and nitric acid alternated monthly. Even when they are completely clean, they are usually full of crystalline deposits/material.

Chlorinated caustic is a contentious choice as while they flush 'clean' there can be significant wort build up at the entry and exit points (these deposit as a syrup at the points of entry and exit as the heat differential is highest at these points) and the pH of this deposit can be enough to liberate the chlorine which quickly eats the metal.

Praise be to the power of peracetic acid is all I can say. That and continual use with hot wort recirculating means they never realise their true foul potential. I would hate to use one for home brew because of how infrequently it would be used and how long it would be sat between uses. They also hold on to a not insignificant amount of liquid, usual practice is to push peracetic through the whole collection and chilling apparatus to sanitise the fermenter then open the kettle, chasing the whole lot with wort discarding the first 30L to drain through the bottom port.

That said, I use a brazed heat exchanger off of a domestic hot water heater for my home brew kit and don't have any problems. That gets similar treatment, but I can always boil, bake or fry the thing if I felt really hard done by. Filtration is key. You will quickly ruin your life sending bitty wort to it.