collection rate

[firefly]

Hi, currently doing a 25L neutral wash run in a reflux still on propane burner..
Trying to collect 10-15ml per minute but it just seems impossible if I aim for 78-79 degrees....
If I keep the heat at 81 or close to 82....I get 10-12 ml per minute....
Been trying to adjust water flow, heat etc...for the last 2 hours and cant get a rate of 10-15ml and keep it at 78 degrees...

So....if I collect the spirit at 81 degrees.....I get a good flow and the alcohol is at 84%......Is it ok to collect at 81-82 degrees????

[HookLine]

What diameter and height is your column?

What packing are you using?

What is the heat input?

What product output rate and %abv do you get at 79ºC?

Is there any difference in the smell and taste of the product at 82 and 79C (after diluting it to approx. 40%)?

[firefly]

Im using the PS II from brewhaus
Using copper mesh
Heat source....propane
Last run I kept it at 79 degrees and the alcohol was at 92%.....but it took over 12 hours.....which is about 3-4 ml per minute!!!

Im still distilling as we speak....the smell(or lack of) seems good enough to me...also tasted it and it seems ok......(at 84%)

Did not dilute yet....out of distilled water for now....

[CoopsOz]

Is it ok to collect at 81-82 degrees????

Yes, this is why cutting by taste is so important. It is all relative to the accuracy of your thermometer and placement in the still. As long as it remains steady, whether it is 79D or 81D it is ok.

[firefly]

Ok thanks coops ...at 81-82.....my rate is at 10-12 ml per minute....
gonna keep it like that for now...thanks again

[SloppyJoe]

I'd like to ask... Why wouldn't it be ok to run at ~81?

I've read all the stuff on the home site but I can't remember anything about distilling too hot... will go back and read more but if you guys could answer why it might be bad to go too hot it'd be helpful as well.

Edit: Ahh.. After reading for a few minutes... I notice that 2-propanol begins to vaporize around 82.. I suppose that's when the tails start?

[firefly]

it says this
Propanol (rubbing alcohol) 82C

so seeing I was at 81-82....im just wondering what i will be drinking???


So im collecting only tails since the beginning....

[HookLine]

Just been checking the liquid/vapour/temperature tables, and the %abv/temps you give sound right. So the issue is the take-off rate.

The PS 2 is a 2" internal reflux still (aka 'cooling management', that uses the two crossed cooling pipes at the top), is that correct? I have never used one of those, but my understanding is that cooling management is harder to control than liquid or vapour management, in particular they are hard to get above about 92-93% abv. So it might just be an inherent limit in the still design. They might only give above 90% if you reduce the take-off rate right down by increasing the reflux coolant flow (which will also get the temp down).

You also might be running the propane a little hard, try reducing that down.

And what Coops said about the exact temperature reading being a bit different for each still, and taste/smell being important.

The lack of smell is a good sign. But if you want to hit 95% at 10-15 ml/min in a 2" column, you might have to go to a LM or VM still.

[HookLine]

it says this
Propanol (rubbing alcohol) 82C

so seeing I was at 81-82....im just wondering what i will be drinking???


So im collecting only tails since the beginning....

If you are hitting propanol, your nose will let you know.

[firefly]

Thanks Hook....I just lowered the heat.....ill see what happens....
and yes, the still you described is the one im using.....


Not sure what propanol would smell like....but if I am in fact collecting it....and I drink it once diluted.....will it be alright????

[HookLine]

Thanks Hook....I just lowered the heat.....ill see what happens....
and yes, the still you described is the one im using.....

Not sure what propanol would smell like....but if I am in fact collecting it....and I drink it once diluted.....will it be alright????

You only have to keep the wash just turning over, a gentle simmer. The more heat you put up the column the harder it is to get the reflux balance right, and the less effective the separation inside the column. It is a trade off between separation and take-off rate.

Propanol 2, which is the first propanol to come off, at just over 82ºC, is also known as isopropanol, isopropyl alcohol, or 'rubbing alcohol'. It is the same stuff used in the sterile swabs they wipe your skin with just before giving you an injection. It is a classic hospital smell. Buy a small bottle of pure isopropanol from your local electronics supplier (it is used for cleaning CDs, circuit boards, etc) and have a smell. You'll never forget it.

No, you don't want to drink propanol 2, it is definitely poisonous. But given its smell you won't be voluntarily drinking anything with much propanol in it, and the amount in your drinkable product would be virtually nil anyway. If your product tastes and smells okay, I wouldn't worry about it. (Assuming, of course, your nose and tongue work okay.)

[new_moonshiner]

I agree with CoopsOz the accuracy of thermometer can throw you off a bit I only use the thermometer to watch the changes not so much the exact temp to run at. once the column stablizes for say 45 minutes or so and the remove the foreshots , the temp of the column should run pretty much one temp through out the run unitill you start hitting close to tails ..thats saying the input power in and water temp stays close to what ya started with. the process is almost automatic .. once you have the takeoff rate set and the water flow set it will sit there and do its own thing my thermometer never moves even one tenth of a degree unless the water starts warming up or the power in changes .. once the temp starts moving around I know the run is almost over im getting close to the tails.. which I dont bother to collect ..One thing I think happens starting out is people over drive the still too much power in .. all you need is just enough power in to make the wash boil nice and steady .. learning to drive the still only comes with time on the still ..

edit didnt see ya already replied Hook ..sorry about that.

[HookLine]

No prob, NM. You gave a pretty good description of the process, and the more the merrier.

After taking the foreshots and heads off, my temp also stays rock solid somewhere between 78.6-78.8, depending on the weather conditions. As soon as the temp starts rising, even just 1-2 tenths of a degree, I know it is almost time to shut it down. I wind the reflux ratio up and run for another 10-15 minutes, then shut down. I used to collect the tails after that, but with my tall reflux column there is so little ethanol left as tails that I don't bother anymore. I keep the heads though.

[firefly]

thanks for all the replies....right now my temp has been steady at 82 and im collecting 10-15ml per minute.....

Last run when I kept it at 78....it took 12 hours to collect 3L (92%)

I just dont wanna get sick or get my friends dizzy drinking my stuff

As for the smell......It smells like alcohol to me.....and I also tasted it at 84% and it tastes pretty good but strong.......

[new_moonshiner]

84 percent is = 168 proof .. yep that would be a tad on the strong side..lol

[firefly]

....still tastes good tough......


If I make no new posts next week.......could be I have died from drinking rubbing alcohol.....

[byacey]

Somewhere I read Isopropyl alcohol isn't really any more poisonous than ethyl alcohol, but it won't inebriate you, so it has little value for our purposes.
On my pot still, the temperature slowly climbs throughout the hearts until most of the alcohol is gone, and then it rises sharply at the end.

Edit: After doing some further searching it appears isopropyl is listed as bad poison, carcinogen etc. depending who you talk to. Some would even say the same about ethyl alcohol too. At any rate, it won't do you any good, so best avoid it.

[AfricaUnite]

Firefly I run the same still and had the same problem as you, in order to get to the 92%+ ABV range I would have to spend many extra hours running the still. I settled on having a final product in the 87% ABV range, it was the best time/quality trade off for me. I broke my thermometer a long time ago so I cant help you out with temps.

[HookLine]

There you go, Firefly, first hand experience from AfricaUnite.

Like I suspected, you just ran into the limits of the cooling management design (or at least, that particular version of it).

[firefly]

Well....I kept a steady temp of 82-83 and after collecting 3L, I shut everything down.....
Final product was 82%
After mixing with a scotch essence....the spirit was really tasty....

I am really not happy about this column......my 2nd run and im thinking of changing it for something that can perform better...

P.S: if anyone can recommend a place in North America where I can get a better column....feel free to recommend something.....


.

[mtnwalker2]

To get the best results with that column, save money and time, and get a much better final product, Do stripping runs with just the top half of your column. Save enough runs of low wines for a spirit run. Make your cuts as recommended in posts given before.

I have gotten 94%+ with that column doing it this way. Cuts are cleaner and easier to make also.

[Husker]

Well....I kept a steady temp of 82-83 and after collecting 3L, I shut everything down.....
Final product was 82%
After mixing with a scotch essence....the spirit was really tasty....

I am really not happy about this column......my 2nd run and im thinking of changing it for something that can perform better...

P.S: if anyone can recommend a place in North America where I can get a better column....feel free to recommend something.....

.

If you want something better than the internal reflux, you might look in the mini-faq. There is a link to a bokabob inline. NOTE the version described is for the "mini-still" However, you can upconvert the plans to a 2" pipe easily. You would probably want to add 12" to the length of the packing (in the mini-still 1.5" tube, the packing is only 18 to 19".) For a 2" tube, that length is not long enough.

H.

[firefly]

well im still trying to solve this and someone suggested not to insulate the column if using indoor.....I think I read on this site the insulate the boiler and the column and so that's what I did...
I doubt my water temp is the problem as I am connected directly to the faucet and the water is freezing cold up here!!!!!

I keep hearing about the stripping runs and doing 3 runs and 1 spirit run doesnt appeal to me right now......

The manufacturer claims 12-15ml/min with 1 run with a spirit of 92%....

Anyway....I will have another look at the the mini-faq again.....

Thanks for the replies.......

[Husker]

I do not run one of these internal reflux stills, so this is an ignorant noob question from me.

How do you hook up the water lines up for these things?

I would think you would have a cold water line, into the bottom of the condenser, with the top of the condenser (warmer) water out. I would think there to be a second "loop" of water (which is NOT dependent upon the condenser water), and this loop would have a set of crossed pipes (or even just a single pipe), at the top of the column. Then you could run the condemner FULL out all the time, and regulate the flow rate in the water loop which goes through the condenser to control the reflux rate.

Is the setup close to what I am imaging? Do other people run their coolant lines like this (or NOT like this). I have no experience, and the instructions I have spent time tracking down on still running, have been for fractionating stills, where you actually "can" have full control over how much (or how little) reflux you dump back into the column.

I would like to see a better set of instructions written up for these internal reflux stills. Something which works, and works well for them. I do not think the how to I wrote for fractionating stills will be a whole lot of help for these stills. But I bet there are people out there who can turn out some pretty neutral product, and have learned how to get the most out of their stills.

H.

[firefly]

Husker.....I think that is exactly what I have

The water goes in to the bottom of the condenser and with a "T" also goes to the top of the column...so I can regulate or close the flow to the column...

Then there is a loop across the column again and the water coming out is again connected with a "T" to join the water coming out of the top of the condenser....

Does it seem clear as I tried to explain it the best I can.....





P.S: the manufacturer just suggested not to insulate the column if distilling indoors.......does this sound correct???

[Husker]

Ok, so you have a pump that feeds a T which splits to the bottom of the condenser, and top of the column. Do you have regulation valve(s) between the T and the input points? I think the only valve "might" be needed for the column side. I think the condenser should simply run wide open all the time.

I had a feeling these things "should" be hooked up like that. However, I have also heard (at least I think so), that some people put the cold water to the bottom of the column, then to the top, THEN to the condenser. To me, that seems foolish/flawed. First off, cooling at the bottom or mid of the column is simply a BAD thing, even if most of those stills are built like that. Now, secondly, you have to control the reflux rate with amount of cooling water. However, if it all is in a closed loop with the condenser, then when you regulate the flow rate of the column water, you are also restricting the flow rate in the condenser (and possibly not having the condenser keep up). I just wanted to know from someone who had this thing working properly, if the setup like I think it should be, is actually the "right" way to do it.

H.

[firefly]

Husker, yes I have a regulation valve and I keep it fully opened.....If I close it somewhat...the temp will rise above 78C

[Husker]

The pix helps, thanks. So even having the reg valve, you pretty much ignore it, and run wide open. The condenser runs wide open also, or has no valve?

I bet when you get more experience with the still, you will find that the regulator valve gets used more. I could be wrong, and it is not that useful, but I would think it should be shut down somewhat when starting, and then gradually opened up more, as the run progresses, and then shut off totally when you get to capturing the tails. However, since I have no practice experience with these internal reflux stills, what I think, MAY actually be exactly opposite of what is really needed to run the still.

H.

[firefly]

As for the valve....it may not be clear on the pic ...but it is attached with a "T" and 1 hose goes to the column and 1 to the condenser.....so I could shut the valve thus having no reflux in the column and all the water going to the condenser or leave it fully opened thus splitting the water to the column and condenser.....
I will take out the column insulation and see if that helps.....

thanks Husker...

[HookLine]

I know it is not the same as your set-up, but just as a comparison, I have a VM column with a coil reflux condenser and a Liebig product condenser. Coolant water first goes into the bottom of the Liebig, out the top, into the coil condenser, (and then lastly out to a collection barrel).

The VAST bulk of the heat exchange in this set-up takes place in the reflux condenser. Barely the top inch of the Liebig gets warm, not even hot. The rate of water flow in this set-up is determined ENTIRELY by the needs of the reflux condenser. The Liebig's cooling needs are tiny by comparison, and the product comes out at the same temp as the coolant in.

With a coolant in temp of about 26-28 ºC, and coolant out of about 45C, and running about 800 w of heat up the column, it uses about 500 ml of coolant a minute.

The Liebig is 800 mm long, which is way overkill for the reflux runs. The reason for it being that big is for when I am doing flat out stripping runs, where it easily copes with 2400 w.