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New Stainless Condenser Build


HedgeBird

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When I originally built our 150 gallon / 4 plate still I also built a 6" x 5' tube in shell condenser to go with it. The original condenser was all copper and had the vapor going through 23 inside tubes and the cooling water in the shell. For a typical distillation run we where going though about 300+ gallons of cooling water. This water is recaptured and used for cleaning and as the mash water for the next run; but as we are only mashing 150 gallons this meant half the collected condenser water was just dumped down the drain.

New condenser is all stainless, 6" x 8.5' (makes the old one look tiny in comparison) has 16 inside tubes, has the cooling water going through the tubes and the vapor though the shell. We also added about 11 internal baffles to force the vapor on a longer path and prevent vapor/condensate from dropping straight down the tube. Big thanks to whoever it was about a year ago who shared pictures of their condenser build and pointed me in the direction or swapping the vapor and coolant and the trick of adding baffles!

We ran it yesterday for the first time and are pretty pleased with the results. Big improvement on water usage and a very noticeable impact on the clarity and oiliness of our distillate, particularity in the feints we are collecting. We now need to get a more sensitive valve to control the cooling water flow as we are using so little and and the current ball valve does not work well for making very small adjustments to the flow. We also need to replace our hoses to ones with a higher heat rating as the water leaving the condenser is now so hot.

I was going to add photos to the post, but the forum keeps telling me I am not allowed so here is a link to the gallery. Starts with a picture of our original condenser, then images of the build in progress and then a few of the new unit in place on the still. Total planning/design time was about 8 hrs, fab and welding was about 10 hrs. Internal plates where laser cut.

http://imgur.com/a/79Jat

Cheers!

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We used about 240 gallons yesterday, but with the current ball valve in place on the water input we are just not able to get the flow as slow as we want it. I have a gate valve on the way that I think should solve this problem, but if not I will look into a needle valve. Most of the current hosing is also only rated to 160F so I don't want to push the exit water past that until I get it replaced. We use an old water meter on the input to give a visual on the flow and keep track of the gallons used. I think it was the cheapest (and coolest looking) flow meter I could find back when I did the control panel.

I do have an adjustable (140F-240F range) thermostatically controlled valve I might try plumbing in place. For those that automate their condenser water flow are you using the condensers outlet water temp as the input variable to control the flow rate? If so, what temperature do you maintain on the outlet? Anyone using parrot temp to control condenser water flow?

post-3967-0-69321700-1455907247_thumb.jp

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I maintain the temp by monitoring the distillate and controlling the heat input. We recirculate from a 1500 gallon tank and pump wide open. When I was dumping the water I would check the exit temp of the water compared to the distillate temp. Then throttled the water down until the distillate started to warm, at that point open the water valve a little. The point being, I was paying for every gallon of water down the drain and wanted enough to cool but not waste the water.

I will have to add some chilling effect to the tank as we move towards summer.

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A really easy way to monitor the water flow rate is with a cheap plastic flow meter that looks like those on MIG gas.

When you can see the flow you might find the current ball valve is good enough to fine tune. I also have dial type of water meter with a little spinning wheel to gauge the flow rate but the plastic tapered tube with "floating" ball is much easier.

You obviously like DIY. I have a cheap PID controller and a washing machine valve to keep temperature constant. You could put the electric valve in parallel with the current ball valve, open ball valve so you don't have quite enough cooling flow. Put sensor in condensate and when condensate gets too hot the electric valve opens to add more cooling. Very quickly the PID will work out how long to keep valve open.

Alternatively you could buy an expensive variable flow electric valve but I like a base flow from the ball valve in case the electric fails and condenser overheats.

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Very nice, thanks for sharing. How much vapor are you condensing ?

Did you notice any difference in the product when using stainless tubes vs copper you were using earlier

When I originally built our 150 gallon / 4 plate still I also built a 6" x 5' tube in shell condenser to go with it. The original condenser was all copper and had the vapor going through 23 inside tubes and the cooling water in the shell. For a typical distillation run we where going though about 300+ gallons of cooling water. This water is recaptured and used for cleaning and as the mash water for the next run; but as we are only mashing 150 gallons this meant half the collected condenser water was just dumped down the drain.

New condenser is all stainless, 6" x 8.5' (makes the old one look tiny in comparison) has 16 inside tubes, has the cooling water going through the tubes and the vapor though the shell. We also added about 11 internal baffles to force the vapor on a longer path and prevent vapor/condensate from dropping straight down the tube. Big thanks to whoever it was about a year ago who shared pictures of their condenser build and pointed me in the direction or swapping the vapor and coolant and the trick of adding baffles!

We ran it yesterday for the first time and are pretty pleased with the results. Big improvement on water usage and a very noticeable impact on the clarity and oiliness of our distillate, particularity in the feints we are collecting. We now need to get a more sensitive valve to control the cooling water flow as we are using so little and and the current ball valve does not work well for making very small adjustments to the flow. We also need to replace our hoses to ones with a higher heat rating as the water leaving the condenser is now so hot.

I was going to add photos to the post, but the forum keeps telling me I am not allowed so here is a link to the gallery. Starts with a picture of our original condenser, then images of the build in progress and then a few of the new unit in place on the still. Total planning/design time was about 8 hrs, fab and welding was about 10 hrs. Internal plates where laser cut.

http://imgur.com/a/79Jat

Cheers!

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With hot vapor on the outside of the shotgun tubes you get extra cooling to the air, but as Hedgebird mentioned those baffles are very important with a slow moving vapor.

I tried to swap sides with a wort heat exchanger and without baffles I could feel that the hot took a short cut straight to other end and left quite a bit of cooling surface unutilized.

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Very nice, thanks for sharing. How much vapor are you condensing ?

Did you notice any difference in the product when using stainless tubes vs copper you were using earlier

Our still is 150 gallon capacity and fully steam jacketed. On a typical run we are collecting something like 40 gallons of distillate. (we do a pretty a-typical distillation process here) We are hoping to be able to change out our water lines this week so we can run at the higher temp and get a true idea of how efficient we can be.

We have absolutely noticed a difference in the product with the new condenser. Previously our spirits always had oils that would float on the surface and sometimes a slight blue tint (copper salts) particularly in the foreshots and tails. This is with us always flushing the condenser after each run and regular cleaning. Now you have to look very hard to find any oil floating on the surface. The spirit is much cleaner with no noticable negative impact on taste/odor.

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Hats off to you HedgeBird, awesome build and a beautiful shotgun condenser ! Very interesting with swapping the vapor for coolant pathway, I've never seen that before.

Just did some quick searching, and it looks like credit for that idea should go to Southernhighlander.

In this thread he gives a ton of great info that I was able to directly implement on this build. Specifically swapping the vapor/cooling sides, adding baffles, extending the baffles past half way, sloping the baffles, etc. It also looks like user Falling Rock was the first to bring the problems with copper condensers to my attention in the same thread.

http://adiforums.com/index.php?showtopic=5692&page=1

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With hot vapor on the outside of the shotgun tubes you get extra cooling to the air, but as Hedgebird mentioned those baffles are very important with a slow moving vapor.

I tried to swap sides with a wort heat exchanger and without baffles I could feel that the hot took a short cut straight to other end and left quite a bit of cooling surface unutilized.

Oddly enough two days after I got this new condenser installed I gave a tour to a guy who worked for a company that has made shell/tube heat exchanges in the past. I mentioned the changes we had made with this one including the baffles and he told me about ones they made that used a continuous screw of metal that forced the hot liquid to move in a very long downward spiral and not just back and forth over baffles. I guess this provides ever more length and a very even/smooth flow. Probably not something we can do in our shop but seems like a great idea!

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Nice!

Any worries about not having easy access to the shell to ensure proper cleaning?

Not really. The old condenser was totally sealed with no access to either the shell or tube. With this one we can at least easily remove the tri-clamp end caps to access the tubes. Even so I can't really imagine trying to clean it with anything other than a liquid we pump though it and do not expect to ever remove the end caps unless something goes really wrong.

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....he told me about ones they made that used a continuous screw of metal that forced the hot liquid to move in a very long downward spiral and not just back and forth over baffles. I guess this provides ever more length and a very even/smooth flow. Probably not something we can do in our shop but seems like a great idea!

That "smooth flow" is not the best for heat exchange. The more turbulent the flow the better

Depending on the number of baffles you have you may get better heat transfer than with a spiral because the vapor is constantly changing direction and creating more turbulence.

Another place to increase turbulence is inside the shotgun tubes, get a strip of metal and bend it into short zig-zags and put inside the tubes to make the water (or vapor) and this will increase the heat transfer.

The insert could be a spiral but the zig-zag is probably better.

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