3" Pot Still Take Off Rate Problem

[angus_young]

Hi guys,

Newbie here but have been reading the forum for more than 6 months to learn and learn. I just bought a 3" pot still from Mile Hi, you can see the photo at the bottom. It was supposed to be an upgrade for my 2" dual purpose tower, I was hoping to do faster stripping runs but nothing changed. I do 5 gallon mashes, mostly UJSM or rum and, abv is around %10-11.

Here are the details of my setup: 8 gallons milk can, pot still tower is 22" tall. Condenser is 36", liebig is 22" (this is where the actual cooling water travels)
3/4" inner tube surrounded by a 1 1/4" jacket. I heard most of you are collecting about 4lt/hr during the stripping run. With this setup I collect 2lt/hr I am using a 65.000 BTU burner and recirculating 60 gallons of water with a pump. I even use a heat diffuser plate on the burner. Water is entering from the bottom of the condenser and exiting from the top. I adjust the water so the top 6" of the condenser becomes hot, this is to not cause vapor collapsing issues. I have insulated the tower also. I threw a couple of copper fittings in the kettle, also used a copper scrubby at the end of the condenser since I had some vapor huffing issues during the first run. Now I don't see any vapor escaping but the take off rate is so slow for a stripping run. I crank up my burner, temperature is around 196F at the top of the tower right before the condenser ( I don't really pay attention to temp) but I still spend 3 hours to strip a 5 gallon wash. Mash is boiling like crazy in the kettle. I am desperately looking for more advice from you masters? Am I doing something wrong or is this what I can get from a 3" pot still?

Thanks in advance and thanks for reading my post.

[kimbodious]

Check all your triclamp connections for vapour leaks, also check the thermometer bung for vapour leaks.
196F head temp, from the temperature chart, is indicating your output would be up around 60%ABV

[pfshine]

How thick is you diffuser plate and what type of metal is it? This might be your problem, have you tried running without it?

[angus_young]

Thanks for the advice kimbodious, I made sure triclamp was tight but will double check everything again. I can't smell anything uncommon around the bung but also don't know what is the best way to check vapor leaks.

Pfshine, first time I ran this tower without a scrubby and the diffuser, all I got was huffing and vapor escaping from the end of the condenser. During the second strip run I used the scrubby and the diffuser, no huffing this time but slow take off rate. Diffuser is 10 " long and smaller than bottom of my kettle which is 13". It is 1/16 of an inch thick.

Forgot to mention, there is no packing in the column also I distill in a small garage, no wind in the room.

Thanks!

[StillerBoy]

I adjust the water so the top 6" of the condenser becomes hot,

On a short liebig (22"), running 6" hot is on the hot side, thereby reducing your ability to use higher input power.. have you tried running it cooler, like 2 -3" hot.. the liebig is the issue with not being able to knock down the vapours faster.. 3/4" inner with an 1 1/4" outer is 1/2" space which will requires lots of water flow..

On my 3" concentric, I strip 7 gal of corn shine of 10% in just slightly over 1.5 hr, from start to finish with 5500 watts a start, and 2800 watts during the strip..

Mars

[ShineRunner]

Seems to me that your diffuser plate is soaking up too much heat. Make sure everything is seated and touching as much as possible. If you’re able to run faster without the plate, to the point of overpowering your condenser, there’s your problem. Run without the plate but turn your power down a bit and you should be golden.

Your Liebig is your weak point and I would also agree with stillerboy that you should try to run a little shorter hot section of the Liebig since it’s on the short side.

SR

[angus_young]

Thanks a lot for all the advice! I really appreciate it. Next time I will remove the diffuser plate and give more power. I will also make sure hot section will be 2-3" at the top of the condenser. Hopefully this will fix the problem. I will let you guys know in a couple of weeks since I have nothing in the fermenter yet.

Stillerboy stripping 7gal in 1.5 hours is really amazing. I was hoping for a similar result from my new tower but it didn't happen. I was thinking if I can't strip fast after trying the tricks you guys told me, maybe I can go with a single spirit run since my tower will give me high ABV distillate. Since I am more into whiskey and rum, it might be suitable.

Thanks,

[ShineRunner]

I think the column doesn’t make any difference for you. A 2” or even 1” column would give you the same output. Your problem is your short Liebig, IMO. The “diameter for speed, height for purity” theory only works for reflux stills. A pot still really doesn’t matter what size the column is if your condenser can’t handle the vapor that’s getting pushed to it.

If you’re overpowering your condenser, putting the plate under it just cuts the heat that’s getting to your wash. If you want to try to get more out of the condenser, you’re likely going to have to slow the vapor down as much as possible so that the little bit of surface area available can work. There are some threads out there, but I’ve seen a couple of options.

I run a shotgun, but when I was using my Liebig, I was under the impression that the scrubbie needed to be on the “business” end. To me, that means the vapor end. It needs to slow the vapor down so that it can condense. You could stuff it up there with a dowel and leave a long piece of stainless wire attached to retrieve it. Another option is a twisted ribbon of copper, but I think a scrubbie would be better. Not sure.

As for making whiskey with your “tower,” I’m not sure what that is. But, if you’re talking about a reflux rig, then you can certainly try it. If you like what it makes, then go for it. Search for a thread by Odin called “making pure whiskey,” or something like that. Pot stills are the best tool for the job because they transfer more flavor. I wouldn’t compromise my product because I didn’t have the right tools. But in the end, it’s your product. If you’re happy with it- then enjoy!

SR

[Bushman]

The “diameter for speed, height for purity” theory only works for reflux stills. A pot still really doesn’t matter what size the column is if your condenser can’t handle the vapor that’s getting pushed to it.

+1

[StillerBoy]

You will need to learn how to dial your unit in.. to dial in a unit,you have to play with the heat input, water flow rate and take off rate.. those three items all work together.. depending on the mash/wash you are running, each one will require a different dial in setting.. keeping notes of each different mash/wash will assist you in setup quicker for each run..

Your propane heater may not be giving your the rated performance stated, and/or your diffuser plate, with propane, will reduced the performance of the burner also.. diffuser plates are best used with hot plate elements, really not required with propane..

So play around with the advise provided and see what happen..

Mars

[angus_young]

ShineRunner thanks for the valuable info! I was under the impression that 3" was going to give me more speed, at least that's what I was told by Mile Hi.

I ran a 5.5 gallon, %9 abv rum wash tonight. I didn't use the diffuser plate; I added 3 small copper scrubbies in the condenser. The total length of the scrubbies was about 10 inches. I cranked up the propane burner and dialed my cooling water accordingly, collected until %20 abv and from start to finish it took 1 hour 50 minutes. Compared to a 3 hour run, I think this was a success.

Thanks a lot for all of the help and suggestions. You guys are life savers and I really appreciate your knowledge. It turns out I learn a new thing with every new run!

[HDNB]

turn up the water . huffing wont hurt a strip run. (or a spirit run imho, but some say it would induce smearing)

make a bigger ID liebig, it will slow the vapour speed and increase cooling surface. maybe a 1" would fit inside that big shell?

[Antler24]

When I do strips runs (not often anymore) I crank the power to max, and open the coolant flow almost all the way. When it starts running I ease the cooling flow back enough that the low wines coming off warm to the touch.

[bronctoad]

Guys he not saying he over powering his liebig . the OP is controlling his water flow to increase output temp.
If there are no leaks, and not lots of unintended reflux, the output being low would have to be heat imput? wouldn't it
just guessing maybe its a burner problem?
bronctoad




whoops guess I need to read all the post in a row
missed your 2nd one there stillerboy sorry for the repeat.