Compact Dimroth as Product Condenser

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NEGaxSEGa
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Compact Dimroth as Product Condenser

Post by NEGaxSEGa »

In building a pot still based on a 1/4 barrel keg, I'm looking for ways to use the copper that I already own. As such, I'm thinking about adding a dimroth product condenser to use up a coil of 3/8" copper and hopefully make my still compact. The still will be run on a propane burner. I may opt to use a bigger, element-driven keg still later. Here's the plan, so far:

As I said above, I'll be running coolant through a coil of 3/8" copper. I'll use a single wound condenser with the return through the middle so that in and out are at the same end of the condenser. I plan to place the coil inside a piece of 1 1/2' copper pipe about 14" long, connected to my lyne arm via a 1/2" -> 1 1/2" reducer. The coolant in and out will penetrate via a couple of T's above the reducer. I chose the condenser housing diameter because it seems to give me a decent amount of vapor contact (stepping up to 2" seems like it would increase the empty space too much), and I think a single wound is all I'll be able to fit inside a housing that size. Running the return up (or down) through the coil is meant to give me a little more contact, and a little more opportunity for turbulence.

So for anyone who's built, or thought about building, one of these, what was your experience? Am I thinking about this condenser correctly? I've played around with the condenser calculator on the parent site, but it seems better suited to sizing up a graham or liebig than a dimroth.
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Danespirit
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Re: Compact Dimroth as Product Condenser

Post by Danespirit »

The first thing to ask yourself is .."How much power will I fire the boiler up with?".
As I read it, it will be sitting on a gas burner for now....going electric is the plan later.
However, I think 14" (350 mm) with a single wound coil, won't quite cut it as a PC.
If you're going with that single coil, I'd recommend a total length of the condenser around 500 mm or just short of 17".
Now I know my coils are RC not PC and made with 6 mm copper piping, compared to your 9,5 mm tubing.
However, maybe you can use my post for what it's worth?
Here you are: http://homedistiller.org/forum/viewtopi ... 87&t=52290
Please keep in mind that I've deliberately made them that short, because of their intended purpose...I just want some reflux going..not cool the product.
Btw...a Graham or a Dimroth... The only difference is the path of the coolant. The Graham has a flow around the coil, opposed to the Dimroth where it's actually in the coil.
A Allihn is basically just a Liebig with a crimped inner tube, whereas the shotgun condenser is a whole different animal.
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Re: Compact Dimroth as Product Condenser

Post by Pikey »

I think That's the wrong way round Danespirit - Graham has the product flowing through it and acts like a coiled liebig. The Dimroth has the cooling water flowing through it and gives more opportunity for the product vapours in the jacket to contact the coolant. (Much easier to clean the outside of teh coil than the inside !)

I run one and this will knock down 2.5 kw using around 1.2 Litres water per minute. It would knock down more, but I don't have any more power in my element :
DSC_0941 resize.jpg
DSC_0943 resize.jpg
DSC_0948 resize.jpg
The coil is wound around a 10mm copper tube which also acts as a bit of a cold finger and the whole lot fits in a 1" tube.

The orientation shown means that there are no perforations and the top of the offset tube is left open. I get no vapour escape, provided my water is running aright!

Hope that helps :)
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Danespirit
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Re: Compact Dimroth as Product Condenser

Post by Danespirit »

Pikey wrote:I think That's the wrong way round Danespirit - Graham has the product flowing through it and acts like a coiled liebig. The Dimroth has the cooling water flowing through it and gives more opportunity for the product vapours in the jacket to contact the coolant. (Much easier to clean the outside of teh coil than the inside !
As I wrote Pikey :wink:
The only difference is the path of the coolant. The Graham has a flow around the coil, opposed to the Dimroth where it's actually in the coil.
https://en.wikipedia.org/wiki/Condenser_(laboratory" onclick="window.open(this.href);return false;" rel="nofollow)
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cranky
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Re: Compact Dimroth as Product Condenser

Post by cranky »

I have Dimroths for both RC and PC on my flute but can also use the PC on my big CM. Mine are really overkill though :roll: and a bit different than what you are making. I find the condenser calculators on the parent site result in way overkill. My RC is made from (I think) 54" of half inch CSST in a 3 - 3.3" tube 7 inches long. My PC is the same thing only two sections to make a 14 long condenser. I do have a short liebig I can add on if I ever felt the need but have never needed to use it on anything, my double Dimroth will knock down everything 5500W will throw at it and then some and that's all I need. I will say that CSST has a whole lot of surface area and thin walled so heat transfers real easy so your results may vary.
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Re: Compact Dimroth as Product Condenser

Post by Pikey »

Danespirit wrote:
Pikey wrote:I think That's the wrong way round Danespirit - Graham has the product flowing through it and acts like a coiled liebig. The Dimroth has the cooling water flowing through it and gives more opportunity for the product vapours in the jacket to contact the coolant. (Much easier to clean the outside of teh coil than the inside !
As I wrote Pikey :wink:
The only difference is the path of the coolant. The Graham has a flow around the coil, opposed to the Dimroth where it's actually in the coil.
https://en.wikipedia.org/wiki/Condenser_(laboratory" onclick="window.open(this.href);return false;" rel="nofollow)
Yes ok mate - My bad ! :oops:
NEGaxSEGa
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Re: Compact Dimroth as Product Condenser

Post by NEGaxSEGa »

Danespirit wrote:The first thing to ask yourself is .."How much power will I fire the boiler up with?".
As I read it, it will be sitting on a gas burner for now....going electric is the plan later.
However, I think 14" (350 mm) with a single wound coil, won't quite cut it as a PC.
If you're going with that single coil, I'd recommend a total length of the condenser around 500 mm or just short of 17".
Now I know my coils are RC not PC and made with 6 mm copper piping, compared to your 9,5 mm tubing.
However, maybe you can use my post for what it's worth?
Here you are: http://homedistiller.org/forum/viewtopi ... 87&t=52290
Please keep in mind that I've deliberately made them that short, because of their intended purpose...I just want some reflux going..not cool the product.
Btw...a Graham or a Dimroth... The only difference is the path of the coolant. The Graham has a flow around the coil, opposed to the Dimroth where it's actually in the coil.
A Allihn is basically just a Liebig with a crimped inner tube, whereas the shotgun condenser is a whole different animal.
That's helpful, thanks. I thought 14" might be a bit too short, but I figure the correct length is somewhere in that ballpark. I'll have enough pipe to lengthen it to 18", which sounds like it'll be enough. Any longer than that, and a liebig seems like it'd be easier and just as practical.

I've read through your thread several times, and I plan to replicate that approach.

One flaw I see in my original post is that I can't possibly run my coolant inlet and outlet into the tubing above the reducer. They won't fit, unless I enlarge the tubing there. Any issue with running them through the wall of the reducer or the housing of the condenser?
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Danespirit
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Re: Compact Dimroth as Product Condenser

Post by Danespirit »

As I wrote, my coils are only reflux coils (RC) and not product condensers (PC).
I recommended somewhere around 17" (500 mm) for a PC, so your 18", will do the job...for sure..
Please share some pictures of your build.
I hope my thread could help you on your way.
Because the same process goes for larger diameter tubing, too. The only difference is, they are a bit harder to wrap around...due to the larger wall thickness.
Should you have any problems, however, annealing helps a lot. A simple blowtorch will do..or a gas burner/weedburner.
Copper conducts heat very well.
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