figuring out a reflux still.

[onon]

I am borrowing a friend’s reflux still and trying to wrap my head around how it is different from what I have used. Here is a diagram of it. Anyone used something like this before. I’ve only run a still a couple of times, and am a beginner. I understand that after cutting the methanol, I would set the reflux back to the riser, so it goes around, but at what point/temperature do I switch it to pour out?

[Sporacle]

viewtopic.php?t=91232

Here's a link on the still type, check the links that Yummy posted as to the still type
Temperature and Methanol can easily be searched
Cheers

[Salt Must Flow]

I really don't like the thought of having a needle valve on the line that returns the reflux back to the column. It looks like it would be an absolute nightmare to get tuned in and REALLY easy to cause the offset portion to flood back through the tee.

This would be an easy way to improve that still. I'd get rid of the 2nd needle valve and have that copper tubing run through the cap and serve as a standpipe. Now all you have to do is adjust your take-off rate with the needle valve and the rest of the reflux would automatically be returned to the column.

Offset LM Fix 01.png

Another way would be to heat the joint joining both tees and pivot the offset head a bit. Remove that 2nd needle valve. The cap on the bottom of the offset tee would need just a little bit of work, but this is only one way to modify this. Now all you have to do is adjust your take-off rate with the needle valve and the rest of the reflux would automatically be returned to the column.

Offset LM Fix.png

Be sure that the top of the reflux condenser is vented to atmosphere. It must be vented to eliminate the possibility of pressure buildup.

[onon]

Thank Sporacle, I will read up. I still do not have an adequate idea of what the story is. It is not my still, so If I can work it as it is, that would be best.

[Salt Must Flow]

onon, do the drawings I posted help you to understand how the returned reflux and the take-off rate is handled with your still?

If you want to operate that still 'as is' then you would have to adjust both needle valves. Adjust the take-off rate with the left needle valve. Adjust the returning reflux with the right needle valve. That's the easy answer.

In reality, what would happen if the right needle valve is turned off? Well the offset head will flood and spill back into the column through the tee.

What would happen if the right needle valve isn't open enough and cannot return the reflux as fast as reflux is being produced? Well the offset head could flood and spill back into the column through the tee.

What would happen if the right needle valve is open too much? The vast majority of the reflux will be returned to the column and can starve the other take-off needle valve and the take-off rate will be very low.

I'd recommend adjusting the right needle valve 'just right' That's a vague recommendation isn't it? Yup considering there's no way for this still, in its current configuration, to automatically return reflux to the column. It will be a BLIND balancing act adjusting needle valve without being able to judge what is happening. It could also cause smearing of your still's output if a relatively large volume of reflux is collected before being returned to the column.

[OtisT]

Hi Onon. When doing your research on how to run this still, you will want to search for LM or Liquid Management. That is the type of column you have there.

I agree with SMFs concerns with tuning that column while running. (It will be hard to find the right balance between takeoff and return flows.). It will be harder because of the dual valves, but doable. This may not be as big of a concern as thought, depending on what is inside that offset head. Is there a weir inside that separates the two valve inputs? If there is, you could simply open the return valve all the way and run it like a traditional LM offset head rig.

Good luck.

[Salt Must Flow]

Is there a weir inside that separates the two valve inputs? If there is, you could simply open the return valve all the way and run it like a traditional LM offset head rig.

EXACTLY! I did not consider that possibility. Good call.

[drmiller100]

If you regulate the reflux only and collect the overflow you only have to tune it once for any given heat.

In other words you don't have to adjust as the wash loses alcohol.
I believe the puddle at the bottom should be designed to be a minimum to reduce smearing of the heads

[onon]

Is there a weir inside that separates the two valve inputs? If there is, you could simply open the return valve all the way and run it like a traditional LM offset head rig.

Good luck.

I've been sidetracked by other concerns, but time is on my side and I prefer to understand what the story is before I run it. Thanks for all the links to background information for beginners like me.

Could I leave the reflux valve open all the way to facilitate the reflux, or close it all the way to simulate a pot still?

I am not sure what the weir is that you are talking about. A barrier that divides the two needle valves?

[Salt Must Flow]

Yes a weir would like a little wall that divides the two ports. It allows any excess reflux to automatically dump back to the column. The only way to know is to take a look inside to see exactly what you are working with.

If running in pot still mode, you would want to close the valve that returns the reflux and fully open the 'take-off' needle valve.

[onon]

Thanks for all of the information available on this site, and the helpful suggestions. This is my second time running a still, and the first reflux. Just beginning to grasp what the story is. I ran it twice, for 20 gallons of sugar mash my son had started last summer. I had to run the mash to free up the four carboys I need for making hard cider. It's that season again.

Used it like a pot still to get the head, a quart jar. I opened up the reflux valve to run the heart, and closed it again for the tails. I twice forgot to initially turn on the water, so the methanol dissipated into the aether. In the first run, I collected the first half gallon ending @ 90%, 80°C, and the second ending at @ 80%, 80°C. Another gallon saw the alcohol slide down to 30% by 93°C. Because of a wild and crazy canning season, I was left without jars, so I collected the second batch in a Corny keg. Nice. I forgot about it for 2 hours. The run took 3 hours from start to finish, as I cut the tails off to save on time.

The reflux worked, as far as I can tell: 92%

[Salt Must Flow]

If the boiler is loaded with a fermented sugar wash then the objective is to do a stripping run as fast as you can (in pot still mode with no reflux returned to the column). Most strip until their total collected low wines is 40% ABV or even a bit lower. You don't make cuts, you aren't concerned about heads, etc...

Once your stripping runs is done, load the boiler with your total collected low wines. They should be 40% ABV or lower. Now you do a 'spirit run' slow and steady with reflux. Collect in multiple jars and do your cuts.

[onon]

Thanks for the Info, Next time.

[Yummyrum]

While looking for something else , I stumbled across the original plans for this still and its dodgy companion .
These are the original plans I found and almost built one if these myself .

https://www.slideshare.net/mrhempAThotm ... -apparatus

[Opdog]

Wow. I haven’t seen that book in years! That was the first thing I found about this hobby back in the day. I remember thinking “That looks like a pain in the ass. I’ll just stick with the pot still”. Then I made a Boka. I never said I was smart.

[onon]

I found a freely accessible version: https://moonshine-still.com/still.pdf

[Yummyrum]

Thankyou so much onon .