Compound Still: disruption of equilibrium??

[Harold]

1. When operating a Compound Still and liquid is collected, and it is [suspected] that collection occurred too rapidly thus [possibly] causing a total disruption in equilibrium, can the still be put back into total reflux mode and allowed to remain in total reflux for at least an hour before collecting again?

2. By placing the system back in total reflux mode for an hour, would this not reestablish “equilibrium” so that collection can begin once again but this time more slowly?

[rad14701]

Yes...

[NineInchNails]

I've read where a lot of people equalize for anywhere from 15, 30, 45 or 60 minutes. Probably something you can play with. I'm sure longer is better, but at what point are you wasting energy for a tiny % benefit?

[Harold]

NIN,

I have no idea. I'm doing my best to read between the lines. The book I am following stated that it takes at least an hour for equilibration. Until I learn more through experience, I suppose I will need to follow the "Letter of the Law" and go with the book's program. Actually, I have two books that say the same thing. This is new ground for me. My past experience has only been that of the Pot Still.

[humbledore]

If you can, build a refluxing still and try running it. Use a simple sugar wash. If you have a thermometer up top you can see the steady temps once equalized . If you take off liquid too fast you can see the temp jump. My point in saying this is that with close monitoring you can get it back under control quickly, which is most likely not "total disruption of equilibrium". It's just a bit of a balancing act between heat input and takeoff rate but it does not require constant adjustment.

[Harold]

If you can, build a refluxing still and try running it. Use a simple sugar wash. If you have a thermometer up top you can see the steady temps once equalized . If you take off liquid too fast you can see the temp jump. My point in saying this is that with close monitoring you can get it back under control quickly, which is most likely not "total disruption of equilibrium". It's just a bit of a balancing act between heat input and takeoff rate but it does not require constant adjustment.

I really need to take a picture of the still and post it. They call this a Hybrid Still. It can be used as three different stills:

Pot
Fractional Reflux
Compound

I am using it as a Fractionating Still (I think) but the reflux condenser is on top of the column so does that make it a Compound or Fractional Reflux Still? As you can tell, I know very little about this apparatus.

[humbledore]

If you post a picture it would help. Generally if you have a condenser on top of the column it's there to produce reflux in the column. But there are several still types that do that.

[Harold]

I will need to travel a short distance in order to take pictures. In the meantime, I will post the following sketch that I did of my setup which will give you an idea of what I have. It shouldn't take too long to post real images.

[humbledore]

Looks like it is from milehidistilling.com? Or at least that is a similar model to what they sell.

[Harold]

Not the best images but they will have to do.

[Harold]

Here's one of the condenser on top.

[Odin]

The moment you start collecting, you are disrupting equilibrium. If you do it too fast, you will lose out on distillation cycles and get a less pure/lower abv product.

Equilibrium is when you are heating, but not collecting, thus giving lower boiling point alcohols the time to find a spot at the top, closest to take-off. Then, by slowly bleeding them off, you lower the lower bp concentration, thus leaving you with cleaner hearts.

How long it takes to stabilize? Good question. Depends on the wash (how much heads present), the efficiency of your still (how many re-distillations) and a few other things.

When I run my rig, I see temperature drop for around 22 minutes after I start equilibrium. That's on a 40 liter 8.5% rye based UJ for instance. Since I run SPP packing, which is very efficient, I can imagine scrubbers need more time. How much more I don't know. Is there a direct relationship towards energy input and the amount of re-distillations? I can easily imagine that ...

Odin.

[humbledore]

Is that a plastic hose on the end of the leibig condenser where the product comes off? Seems like you've been here a while, did you get the speech about plastics being a no-no? And rubber bungs, stoppers, gaskets, etc. I'm sure someone other than me will chime in on that.

Looks like a CM still to me. Which means you control reflux by your cooling water flow. Read this if you haven't:

http://homedistiller.org/forum/viewtopi ... 60&t=13360

[rad14701]

Yep, that's a jacketed Cooling Management reflux column that can also be run as a pot still... Those temperatures in the diagram are merely a snapshot during a run, not constants, as they will change throughout the run...

[emptyglass]

Big Bert has one of these stills. Maybe he could give you some tips as to how he runs it. If he doesn't chime in, you could send him a PM.
Rad was right with his first reply.

[Harold]

Hi EmptyGlass,

I would love to talk to Big Bert if he has a rig like mine and if he's willing to talk to me. There is no doubt that I am harvesting a good product but I really don't know the *proper* procedures/method for operating this rig. I have several questions ..... some being simply, e.g., "How often is the rig to be cleaned (to include copper scrubbers)? How often are CU scrubbers to be *replaced* with new scrubbers? and What cleaning materials and methods should I use"? Then I have some very specific, pointed questions regarding temp and collection. I think all these questions and answers are best handled using multiple PMs.

I've been without sleep for 26 hours and the run is finally over. I'm going to bed with hopes I will get some guidance from Big Bert by tomorrow.

[emptyglass]

The answers to all your questions are right here, you just need to look.
I suggested using the PM system to contact Big Bert, but you are not annoying anyone discussing it here, after all that's why we all come, to learn and share. I'm sure there will be others that would benefit from what you learn about your still. They cant do that via PMs

[pounsfos]

hoq quickly you get into equilibrium depends on how efficient your column is and how high

it takes my stil about 7-10 mins to reach equilibreum

my old still use to take about 45 mins......

the more packing, and the more efficient the packing is will help shorten the time frame

but if you disrupt equilibreum, just close the valve and let it settle again

[Bushman]

but if you disrupt equilibreum, just close the valve and let it settle again

No valve on a CM still. Early readings and books written prior to 2009 suggests an hour for your still to reach equalibrium, we now know that that isn't always the case as we have improved on the designs. I always let mine go a minimum of 30 -40 min. depending on the product.
We do not promote plastic at anytime touching the vapor or product as was mentioned you have plastic lines for collection. Having said that a lot of micro distilleries in our area are using a food grade plastic lines. When I ask them most say that it is not in contact with the product that long but my fear is over time that would break down thus needing constant monitoring.
On your reflux water lines I would switch the water in to the bottom and water out at the top.
As you will find out after a few runs with a CM still you can have great control but it takes time to learn. Things take a moment to react so make small adjustments to the water pressure in when starting to collect and then wait a few minutes to make another adjustment if needed otherwise you can over compensate and start collecting to fast and loose equalibrium.

[Prairiepiss]

Reading the cm mod thread. Link in my signature. Mite help you along.

Where is your thermometer mounted?
If it is above the reflux condenser. You will never be able to use it to determine if the column has equalized.
If it below the condenser. Then you would be able to see the temps equalize.

Depending how you have you cooling water routed? This can also give you temp swings. The still starts chasing temps around if the reflux condenser is fed by the product condenser output. Can be remedied with the more from the cm mod thread.

Basic operation.

Heat up like a normal pot still.
As soon as the top gets to hot to the touch. Start flow to the reflux condenser. And turn the heat down to where it runs best. Allow it to reflux for anywhere from 30 min to an hour. Up to you. Now slowly decrease the flow through the reflux condenser. Until you start getting product off. Adjust to get the takeoff speed you want. Slow 3 drips a second. Will achieve a higher ABV. While a faster takeoff will provide a lower ABV.

Optional to take it back into 100% reflux after the fores are taken off. To restack the column.

It will take some experimenting on your part to figure out how best to run this still. Mainly because for best results you need to use both cm cooling management and pm power management. Finding the best settings for coolant flow and heat input isn't a given. You need to find what's best for you and your still. Different washes will also need a little tweaking.

I personaly don't use a thermometer on my cm still. I do have a parrot and use a alcohol meter to gauge what is happening.

[Harold]

Reading the cm mod thread. Link in my signature. Mite help you along.

Where is your thermometer mounted?

My thermometer is located above the reflux condenser. Looks like I need to modify my column to relocate thermometer.

I do not have a heating element. I use gas heat.

[Harold]

but if you disrupt equilibreum, just close the valve and let it settle again

1. No valve on a CM still.

2. On your reflux water lines I would switch the water in to the bottom and water out at the top.

1. Yes, the books I am reading mention a valve. This caused me concern. Their writings strongly suggest, without the books ever saying so, that the System they are describing is a "CLOSED CIRCUIT SYSTEM". In their diagrammatic illustrations, there was no mention nor provision for a safety relief valve. My understanding of a "Closed System" is one that allows nothing to enter or exit. Applying heat to a closed system invites disaster unless there is a way to manage internal pressure increase. Am I to assume that internal pressure is supposed to somehow be "regulated" by water-flow to the reflux condenser?

There is no valve on my unit. I have been controlling discharge of distillate (from no discharge to a slow drip) by the amount of water flowing through the reflux condenser. My system is not a Closed System. Increasing water flow to the reflex condenser will prevent product discharge ..... but the system is not "closed". When sniffing the discharge tube during full reflux mode, odors can be detected in the absence of distillates. Careful decrease in water flow will allow passage of small amounts of vapor that will condense in the Liebeg and I have found this to be easily metered albeit a slow lag-time between the time of adjustment to the time of discharge. Though I am controlling water to the condenser with the accommodations I currently enjoy, I would love to have a very nice large stainless metering valve in line between water source and reflux condenser.

2. I am glad you mentioned positions of water-in and water-out on the reflux head and the need for a separate water source to each condenser. I had already decided to make those change. It just makes good sense to have the ability to independently control each condenser. Assembly instructions were poor and contrary to correct setup.

[Bushman]

There is no valve on my unit. I have been controlling discharge of distillate (from no discharge to a slow drip) by the amount of water flowing through the reflux condenser. My system is not a Closed System. Increasing water flow to the reflex condenser will prevent product discharge ..... but the system is not "closed". When sniffing the discharge tube during full reflux mode, odors can be detected in the absence of distillates. Careful decrease in water flow will allow passage of small amounts of vapor that will condense in the Liebeg and I have found this to be easily metered albeit a slow lag-time between the time of adjustment to the time of discharge. Though I am controlling water to the condenser with the accommodations I currently enjoy
Correct
2. I am glad you mentioned positions of water-in and water-out on the reflux head and the need for a separate water source to each condenser. I had already decided to make those change. It just makes good sense to have the ability to independently control each condenser. Assembly instructions were poor and contrary to correct setup.
This configuration will be more efficient

[Big Bert]

Hi Harold,it looks like one of MHs units, the boys have all given good advice. The way I run mine is to get the boiler temp. up slowly( takes me 1 1/2 hrs) till it reaches 80 C then I turn down the heat source a little to try to hold it there, it will continue to rise but at a slower rate. I run the coolant to the reflux and PC in separate lines,in at the bottom out at the top, both valved at the bottom, while the boiler is heating I run a small amount of water thru the reflux and non thru the PC,when the head temp reaches 80c you will note that a small amount of liquid and steam coming out the PC ,I then crank the water flow to the reflux camber up putting it in full reflux for 20 to 30 minutes ,then turn on the coolant to the PC and turn down the flow to the reflux ( slowly ,make small adjustment till the head temp rises once again to 78c) this should give you a flow rate of about 2 lts an hour at 180 plus with no problem,it should run this way for at least 4to 5 hrs with no more adjustments. The boiler temp will rise over this time at a slow rate up to around 95c ( over the 4/5 hrs) and the head temp will rise to 80/82c ,this will drop the proof to around 170, at this time I shut it down, one can continue to collect at a lower proof and use it in the next wash,I don't .Flow rate of the cooling water will depend on the temp of your water.
I have a few of these units and this is how I run them (2"-3") both the same. It is possible to run at a faster flow rate per hour( up to 4 lts per hour) by running the boiler temps higher and increasing the water flow to the reflux camber but it will cost you a little on the proof. If you take your time you will get great product at a slower rate but it will get you drunker faster.
Works for me
BB

[Big Bert]

Hi again, almost forgot at the end of the run after the unit has cooled down I remove the tower from the boiler and reverse flush it with cool water,then let it stand on end with both ends open to the air to dry out. The cooper or SS packing is good till the copper turns black,then pull the packing,clean tower with hot water,repack with new and get back at it.
Works for me.
BB

[Harold]

From reading quite a few posts, I have noticed that some individuals do not dilute 60%-70% or even 80% abv before beginning a spirit run. I was under the impression that anything above 50% should be diluted when making a spirit run.

Is this safe?

I do the following:

1. Clearing run in Pot Still, and throw away foreshots, then collect everything until the first sign of cloudy runoff.
2. Double back in Pot Still, collect and throw away foreshots, then collect everything having no appreciable off taste.
3. Cut “double-run” with distilled water to 45%-50% ETOH (measured with refractometers)
4. Place “double-run” in CM (cooling management) system


1. Allow temp to rise in column to 160F (72.2C) and then apply water flow to reflux condenser. Slowly increase or decrease water flow to reflux condenser until temp stabilizes at 167F-168F (76C-75.5C) and maintain temp for one hour.

2. Slowly decrease water flow to reflux condenser, in steps if necessary, until temp rises to 170F (76.6C). Hold that temp, as best as possible, using CM at reflux condenser. Collect “drip-flow” (80 to 100 drops/min) until drippings slow to 12-14 drops/min. Totally discard collection.

3. Lower reflux condenser temp to 168F (75.5C). Allow system to reflux for 30 minutes.

4. After 30 min, allow temp to increase to 170F (75.5C). Hold at that temp and collect until there is either no foul taste/smell OR until drippings slow to 12-14 drops/min. Put system back into reflux mode for at least 45 minutes.

5. After 45 minutes of reflux, slow water flow and attempt to stabilize temp at 171F (77.2C). Discard anything with off-taste and then increase temp to 172.5 (78.05C) and begin collecting at a rate of ~100 drops/min. Continue collecting until dripping rate slows to 15 drops/min, then save all collection. Slightly lower temp several degrees, and place system in reflux for at least 45 minutes.

6. After 45 minutes of reflux, increase temp to 173F (78.3C), check for “off-taste” and discard “off-taste” if present. Continue collection at “full bore” and save collection until rate falls below 80 drops/min. Place system back into reflux.

7. After 45min to 1 hour of reflux, increase temp to 174F (78.7C) and begin collection. Taste-test frequently. Collect until conjures become noticeable. Switch collection container and begin collecting conjures until conjures become stronger but not repugnant. Shut down system. Run is over.

*NOTE* Because my thermometer is mounted above the condenser, I begin to realize strong conjures most anytime my temp rises to 175F (79.4C). I make every effort to keep my temp at 174F (78.7C) with an occasional spike to 175F (79.4C). I attribute the short-lasting-spike to my well-pump kicking on which increases momentary water flow.

This is how I have been operating my CM system.

Any suggestions for improvement?

I am switching to a re-circulating system and an electric submersible water pump (which will keep water-pressure constant); I don't like wasting well-water. Keeping re-circulated water cold in Alaska will never be an issue. We have plenty of snow to cool the water.

Any precise instructions/directions for installing a thermometer below the condenser would be greatly appreciated. I have no idea what is involved in installing a thermometer or any idea what fittings are required. Illustrations or drawings would be appreciated.

[Odin]

Always dilute to 30/40%.

Odin.

[Big Bert]

Jees, Harold that sounds like a lot of work,I have a few cm stills and I have no problem running at plus 180 proof on a singal run and it is clear and pure,no off taste or smell,then I cut to 105 proof and filter .i always lose about 5 points on the filtering so I end up with 100 proof that tastes like water with a kick. If I am going to run it through my flavour cage I cut it back to 40 proof and collect all( I find there is no heads or tails just all hearts) . I guess we all do things a little differant which is good, if we all did the same thing God forbid we would all be drinking beer and I would have to quite drinking. If you ever run that still with the gin basket I would like to know how it works,I have a setup smiler to it and mine works well.
Best of luck
BB

[Big Bert]

PS, I have also put a flute plate between the boiler and the basket and have used a screen instead of the plate and filled the basket(4x2) adaptor half full of ceramic rings, both help to drive the proof up.
Works for me

BB

[Harold]

Jees, Harold that sounds like a lot of work,I have a few cm stills and I have no problem running at plus 180 proof on a singal run and it is clear and pure,no off taste or smell,then I cut to 105 proof and filter .i always lose about 5 points on the filtering so I end up with 100 proof that tastes like water with a kick. If I am going to run it through my flavour cage I cut it back to 40 proof and collect all( I find there is no heads or tails just all hearts) . I guess we all do things a little differant which is good, if we all did the same thing God forbid we would all be drinking beer and I would have to quite drinking. If you ever run that still with the gin basket I would like to know how it works,I have a setup smiler to it and mine works well.
Best of luck
BB

Good Evening BB,

I seem to have a propensity for “leaping before I look”. There were “Visions of Grandeur” when purchasing this unit coupled with high expectations, but then came reality. After jumping head-first and buying this CM Still, I decided that I should buy a book ….. in fact several books which came close to comprehensively addressed CM. It was only then did I come to realized, base on what I was reading, that CM requires far more time and care than ever imagined. I stress, Based On What I Was Reading.

When following directions from each book, the CM Still performed magnificently. I was very surprised when I distilled a LARGE quantity of nasty foreshots otherwise thought to have been removed during my double run in the Pot Still. So, reflux definitely did its job. I was careful, vigilant, and obedient. However, despite the product having been distilled twice in the Pot Still and once in the CM Still, the distillate (after having been cut to 100%) was “HOT” and that was a big disappointment. I decided to re-distill the product ONE MORE TIME using CM. This took over twenty hours. Once again I got about half-a-pint of nasty foreshots. Again I was very surprised. Based on readings from my refractometer, each CM run produced 80% ETOH (160 proof). Again I cut to 100 proof and again the product was HOT but not as much as before. I ended up with a little over two gallons of 100 proof after cutting. I attribute the product being HOT to the possible presence of Ethyl Acetate. But Ethyl Acetate should have been the first to cross over as foreshots and especially so when using reflux. The one thing I have yet to try is filtration. Aside from that, I’m at a loss.

So, not only does it sound like work (as you have stated), it is work and requires many hours of attention. I have resigned to the fact that this system requires hours and hours of attention. Having said all that, I should neverf discount the possibility that I am at fault somewhere along the way. Modifications are being made, e.g., re-arranging the hose on the reflux condenser. I have operated the still only three times. After the first and second run I washed the cooker but I have not wash the column and packing.

Can I be picking up “bad stuff” because I haven’t scrubbed the column and packing? I’ve been thinking about using a citric acid wash to clean the column and packing. I’ve even considered removing the packing and washing each roll individually. What thoughts do you have on that method of cleaning? Is this over-kill?

Oh, and by the way, when the product was cut with distilled water and run the second time through the CM Still, at first (after the product was cut to 100 proof) the product was very mild with no burn, what so ever, but the longer it stands in jars the hotter it becomes.

Why is it getting hotter?