Otis’ 4” VM/CM Column Build

[OtisT]

I’ve been running my 4” column as a Cooling Management (CM) system for the last year, and it was good to learn and get used to running a CM. That said, I am extremely happy to have finally completed the 4” Vapor Management (VM) head so that I can go back to running VM. I’ve been staring at those damn cut stainless parts for over a year and I’m glad that is finally done. Thanks to my good friend Larry for getting this welded up.
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I wanted a low profile VM port due to my current shed’s height limitations and here is what I came up with. This is the new head before I cleaned and passivated the stainless.

4” x 2” low profile VM Head

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Below is a closeup of the upper section of the column in VM configuration.
I made a short 1/2” copper extender for the thermometer port so the thermometer probe does not get liquid reflux running down on it.
The valve is a 1” stainless gate valve.
I run that PC as a Dephlegmator when in CM mode. Here is that build: viewtopic.php?f=17&t=81513
The top of the PC is open. I have a 4”x 2” reducer clamped on there now.

My 4” column configured for VM

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The pic below is just a wider view showing the shotgun PC attached. I typically add a spool or two to lower my PC to where I want my collection jars. Next on my build list is a jar shelf that mounts to the shotgun so I can safely run with the PC at any height.

Upper section of the 4” VM Configuration

Otis

[Yummyrum]

I like that Otis .
What packing are you using ?

[OtisT]

Thanks Yummy. For packing I have been running this 1/2” - 1/4” Cinder Rock. I started with 3/4” minus cinder rock and ran that through a 1/2” screen to remove the larger rocks. I took the smaller rocks from the first pass and ran those through a 1/4” screen, and I am using the rocks that did not pass through that smaller 1/4” screen.

1/2” to 1/4” cinder rock

I only have 5500w and that seems a bit under powered for the 4” now. Not even close to flooding this thing, so I want to try swapping out my current rocks for the smaller rocks that passed through the 1/4” screen. I am hoping to get a little bump in ABV with the switch. I’d like to get rid of the smallest of the small rocks in this batch though, so I am looking for a 3/16” screen to grade these one more time. This is what I hope to be running with soon, once I find that 3/16” screen to pull out the smallest bits.

1/4” minus cinder rock

Otis

[ThomasBrewer]

https://www.mcmaster.com/mesh/opening-s ... size~3-16/

[zapata]

Nice build, I likey. I wonder if switching to a 3" column would help give the proof bump you're looking for? In theory it would better match your element, have a better diameter / height ratio, keep HETP low through better liquid distribution, and allow you to play around with the very wet almost flooded state that seems to work well for at least some with lava. Some 3" 304 exhaust tubing soldered/welded to a drilled endcap (link) would have it done for $75ish and not lose any height in adapters.
https://www.glaciertanks.com/tri-clamp- ... utout.html

Just a thought, the head is sweet, good work.

[OtisT]

Thanks Zapata. I do have a 3” column and it works great on my boiler. I’m having fun building and trying 4” at this height. I don’t plan on being in my current place for more than a few years and expect to have some height to grow into then. Building is my therapy, and I need a lot of that these days. Otis

[Salt Must Flow]

OtisT, try checking out some kitty litter scoopers and measure the gaps. I just measured one here and the gaps are .2" which is really close to 3/16" like you are looking for. That's what I used to sift my lava rock with for my 3" VM still. It worked very well.

[OtisT]

Great idea there SMF. The stainless scooper I use does have 3/16”+ wide slots. Once I clean the hell of of this thing, I think it could do the trick. It’s gonna let a lot more through than a square screen because the holes are 3/16” wide but elongated over an inch. Time for some cleaning. Otis

[Salt Must Flow]

Great idea there SMF. The stainless scooper I use does have 3/16”+ wide slots. Once I clean the hell of of this thing, I think it could do the trick. It’s gonna let a lot more through than a square screen because the holes are 3/16” wide but elongated over an inch. Time for some cleaning. Otis

Yup, my lava rock has a good amount of elongated pieces that wouldn't have otherwise passed through.

Your reflux condenser looks really interesting. I'll have to take a closer look at that and how it works.

[StillerBoy]

Beautiful work Otis, my complements to your skills..

Building is my therapy, and I need a lot of that these days. Otis

I do believe we are of the same view on therapy of building, plus assisting others in their journey in the hobby..

Beautiful work..

Mars

[OtisT]

Thank you Mars.

SMF. Thank you for the suggestion. Just ran my 3.5 gallons of rock through the scooper. The gap is a bit big, so I had to run the material through three times quickly to keep the 2.5 gallons of material I need to fill my current max height of 45”. I wish I had more material to be more select but I have enough for now and it looks better. I’m gonna clean this rock up for my next neutral run. Here is a link to that condenser build. viewtopic.php?f=17&t=81513

Thanks again.

Cat poop grade rock

Otis

[squigglefunk]

thats a bad mama jamma

[OtisT]

I finally washed my new packing and was able to get in a cleaning/test run today. I can’t tell you all how excited I am to finally have this new head and to be able to run my column like a VM again. And I’m very happy with the results.

I ran 5 gallons of 28% feints. That would be 5.4 liters at 93%.
Running the column within an inch if the ceiling, I was able to get 52” of packed rock.
I love this space saving head.

It took a shoe horn to get 52” of packing

I let the still settle in at 5000w under full reflex. 3.5 lpm cooling for just warm output.
I took samples at various takeoff rates:

Turns open / 100ml time / 150 ml time / temp / abv
3 / 5:35 / 8:50 / 170.5F / 95%
5 / 2:35 / 4:00 / 170.5F / 95%
7 / 2:00 / 3:00 / 171-F / 95%
9 / 1:36 / 2:35 / 172- / 95%
11 / 1:35 /2:30 / 172- / 95%
Full / 1:28 / 2:17 / 172- / 95%
My 2nd and 3rd liters came in at 94.5%
(The abv’s were all done together after the run. I brought them all to the same temp, rights at 60F so I think this is accurate.)

I had collected 1.5 liters by the time I had taken all my samples. Around 2 liter collected the still flooded. I collected a sample
While flooding and it was 94.5% abv. After collecting I shut down to add back 2” of rock that had settled with the flood.

5000w flood

I powered up to 4,800 watts under full reflux for 5 minutes then began collecting again. It flooded a liter collected later and my rocks settled another inch.” After a brief shutdown I powered up to 4,000w for the rest of the run. Output dropped significantly after 3 liters collected so I stopped there.

It was a fun day breaking in the new rocks so I can run some neutral soon. A few surprises today. I did not think I would hit 95% abv. I did not think I could maintain the max abv with the 1” valve fully open. I was surprised it flooded, and surprised it took so long to flood when it did.

I could hear the flood coming before it showed up. I had a piece of paper on top of the column so I could see it get wet if any vapor was escaping. When the flood was working its way up the column, airflow was huffing at the top of the column causing the paper to rattle. That’s what I noticed first. Then I could hear it in the column once I knew what to listen for. I could hear it rise until it showed as a flood in my sight glass. I think I could use a bottom screen with more open space.

All in all, a fun day. Otis

Still in and Chillin

[OtisT]

I hope to fix my flooding issue. I have a theory to test that I hope will work.

I was able to run the column at full power without flooding when I used the larger grade of rocks, but my ABV was lower by comparison. Using the smaller rocks at high power, a flood would start at the base of the column and work its way up. I think I may get the best of both worlds if it had better drainage in the bottom 12” of the column, where most of the separation takes place. I realize I may just be moving the issue 12” up the column, but I hope not. Here is what I plan to try.
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Same baseplate. Maybe drill these out a bit bigger if this test fails. It did work for me, as is, with the larger rock.

4” Filter Plate at the base of packed column

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To keep rocks from plugging the holes, there are two layers of 1/8” copper mesh on top of the screen plate before Rocks are put in.

1/8” copper mesh, two layers

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The bottom 12” was packed with the coarse grade rock followed by a layer of copper mesh, topped with 40” of the finer grade rock.

Two grades of cinder rock

Copper mesh between grades of rock

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I should have a lot of neutral low wines to test with in a few weeks. Can’t wait to give it a try.

Otis

[Salt Must Flow]

I've been through EXACTLY what you're going through. To fix the issues I was having with low ABV, flooding, etc... was to get rid of absolutely any restrictions, remove any perforated plate, ditch the wire screen and support a few rolls of copper mesh then Lava Rock over top with this type of support:

Just Dremel away the interior of a PTFE gasket and Bob's your uncle.

I sized the Lava Rock for my 3" VM I believe the same way you did (same size). I kept the smaller bits and sieved them again to get a more uniform size. I recently attempted to try using the smaller Lava Rock to see if it would work the same if not better than the original size that worked perfectly. It didn't. After a while I could hear a sizzle sound in the column then later it flooded. It would not run at the same power setting (2750W) as the larger size Lava Rock. My point in this little story is that if removing the restriction/restrictions doesn't solve your problem, it could also be the small rock that's the problem and you should stick with the larger size rock.

With my 3" VM running at 50% power (2750W) I get 3.2 LPH takeoff of azeo with my 1" gate valve open 6 full turns. I could probably push it harder & faster, but I haven't tried yet. Your 4" clearly should be capable of MUCH faster takeoff rate than mine. When running my 3" at 100% reflux at 5500W it would NOT flood and had no indication of any sizzling sound at all. It just sounds like 'hhhhhhhhhhh'. I use a Stethoscope to listen to the column too so it's very easy to detect. This leads me to believe that the size of the larger Lava Rock is NOT your problem and the flooding is caused by your restrictions at the base of the column and the smaller size rock. Also when my smaller Lava Rock flooded, the sizzling sound started approx 17" from the top of the column, accumulated and was later visible in my sight glass. When I very first started distilling, the restriction at the base of my column caused flooding, it started at the bottom and took much longer before it showed up at the top of the column.

I think your problem is very simple. Ditch that perforated plate and use the original larger Lava Rock. Personally, I wouldn't even bother drilling out the holes in the plate unless you really want to test it out.

[Salt Must Flow]

I don't know if this data will help, but I recently stripped an 8% ABV sugar wash with my VM. My 1" gate valve was wide open at 5500W and takeoff was 4.6 LPH at 70% ABV. I don't know if this data (takeoff rate) would in way translate to a spirit run. My thought is maybe in the future you might benefit with a large gate valve. Just a thought.

Next time you're at Lowes, check out the pipe insulation and there should be soft, rubbery, almost neoprene pipe insulation. That stuff works amazing and surprisingly much better than the polyethylene foam insulation. Works better than multiple layers of Reflectix too.

[Oatmeal]

I've been wondering about this project. Thanks for the update.

[drmiller100]

With marbles on a normal reflux still my 3 inch will flood first at the bottom.
Very coarse 1/4 inch mesh shaped into a bowl at the bottom helped tremendously.
4000 watts on 3 inch.

As a stripper I had to go to 4 inch which is almost double for the same horsepower.

[Salt Must Flow]

With marbles on a normal reflux still my 3 inch will flood first at the bottom.
Very coarse 1/4 inch mesh shaped into a bowl at the bottom helped tremendously.
4000 watts on 3 inch.

As a stripper I had to go to 4 inch which is almost double for the same horsepower.

For real? You do a spirit run at 4000W? I never considered running that high of power. I'd love to know what your takeoff rate is and the % ABV. I haven't pushed at all that high. I hate the taste of tails so tend to back off.

[drmiller100]

With marbles on a normal reflux still my 3 inch will flood first at the bottom.
Very coarse 1/4 inch mesh shaped into a bowl at the bottom helped tremendously.
4000 watts on 3 inch.

As a stripper I had to go to 4 inch which is almost double for the same horsepower.

For real? You do a spirit run at 4000W? I never considered running that high of power. I'd love to know what your takeoff rate is and the % ABV. I haven't pushed at all that high. I hate the taste of tails so tend to back off.

I only make fuel stills. Should have clarified. Sorry.

My big continuous still makes 2 to 2.5 gallons of 95 percent per hour from 10 percent beer.

Absolutely horrid tasting.

[Chauncey]

Probably not far from the bottled gns products available from the distributors here...like Mohawk etc etc. The horror.


Otis, stellar work!

[OtisT]

As suggested, I’m going to build a new bottom plate so I can run the finer grade rock without (much) flooding.

I recently completed back to back distillations with the two different rock sizes. Results below.

Some things were the same for each run
* 8 gallons of 22% low wines - expecting to collect 6 liters total per run
* 52” of total packing height over a filter plate
* 3 liters/hour collection rate: 7 turns open

Fine grade rock distillation run
* 52” of packing: 40” of fine grade over 12” of course grade rock
* 94% ABV product (172.5F)
* Flooding at high power. Ran collection at 4000W

Flooding. The column would flood from the top at 5500w at full reflux. It would run without top flooding at 5000W. After ~15 minutes of operation at 5000W the column flooded, and I’m guessing from the bottom. Power was lowered to 4000W for the remainder of the run with no further flooding. As suggested, I need a more open bottom plate to prevent flooding from below.

Course grade rock distillation run
* 52” of coarse grade rock packing
* 92% ABV product (174F)
* 5500W, no flooding

Most of the run was done at 5500W. I temporarily dropped power to 4000W during the run to collect a sample for run ABV comparisons. (No difference in ABV between the two power settings.)

Going forward
I’m going to build a new bottom plate so I can run the smaller rock. I want the higher ABV and don’t want to worry about when the flood may come due to that bottom restriction. The small rock will still flood with too much reflux, but at least that comes from the top and is easier to see and deal with.

Otis

[drmiller100]

I'm very puzzled as to why you can't reach azeo.
50 inches of about any packing should easily reach azeo on full reflux.

[StillerBoy]

Otis.. if you are using the perforated ss plate shown in the picture.. it will flood on you cause it's restricting distillate return, thereby your ABV level..

Mars

[Salt Must Flow]

Otis I totally understand thinking that the smaller rock would have more surface area and 'should' perform better. That is precisely what I tried and my 3" flooded over and over, couldn't even run at the same power that the larger rock does and the larger rock maxed out ABV.

Here's a theory. Have you really listened close to the sound that your column makes while using the larger rock? It should be making a 'hhhhhhhhhhh' sound from top to bottom. I wonder if it is making a sizzling sound, but not actually entirely flooding. That could be causing the lower ABV. That's happened to me with other packing like stainless scrubbers if they were packed slightly too tight. When I hear sizzling I always get lower ABV. Whenever I got lower ABV I also always hear sizzling. Larger column requires larger rock. I've read posts about column diameter and the size of lava rock required. I went with that recommendation for my 3" and it works flawlessly, but NOT with smaller rock. It appears you're using the exact same size in your 4" that I use in my 3" and maybe that's the problem. My theory is maybe you need slightly larger Lava Rock.

I bought a pretty inexpensive stethoscope on Amazon so I could listen easier, more effectively and I haven't regretted the purchase.

[OtisT]

I'm very puzzled as to why you can't reach azeo.
50 inches of about any packing should easily reach azeo on full reflux.

My understanding is that the larger the column diameter, the more height that is required to reach the same level of separation.

[OtisT]

Otis.. if you are using the perforated ss plate shown in the picture.. it will flood on you cause it's restricting distillate return, thereby your ABV level..

Mars

Yes I am using that plate. It only floods when combined with the smaller rocks. I do plan to replace it. I guess you did not read the thread.

[OtisT]

Otis I totally understand thinking that the smaller rock would have more surface area and 'should' perform better. That is precisely what I tried and my 3" flooded over and over, couldn't even run at the same power that the larger rock does and the larger rock maxed out ABV.

If by perform better you mean produce a higher ABV, then yes the smaller rock should and did perform better. I pulled 2% better ABV with the small rocks at the same production rate.

I do listen to the column when running. I may have to pick up a stethoscope. Way cheaper than a glass column. I was running an extra fan on myself during these recent runs, to hot, so I could not hear the flooding as well this time as the previous time I ran it.

[Salt Must Flow]

Otis I totally understand thinking that the smaller rock would have more surface area and 'should' perform better. That is precisely what I tried and my 3" flooded over and over, couldn't even run at the same power that the larger rock does and the larger rock maxed out ABV.

If by perform better you mean produce a higher ABV, then yes the smaller rock should and did perform better. I pulled 2% better ABV with the small rocks at the same production rate.

I do listen to the column when running. I may have to pick up a stethoscope. Way cheaper than a glass column. I was running an extra fan on myself during these recent runs, to hot, so I could not hear the flooding as well this time as the previous time I ran it.

I get what you're saying, but you did say that you got 94% at 4000W (lower power) with the small rock and 92% at 5500W (higher power) with the larger rock. This kinda correlates if you think about it. Small rock can't handle it at lower power and the larger rock can't handle it with higher power. I believe your larger diameter column needs larger rock. 2" can use the smaller rock. 3" can use the larger rock you're using and that's a proven fact. Your column is likely 3 times the cross-sectional area as 3" without me doing the math to confirm. It only makes sense to me that you need larger rock.

[Yummyrum]

What always gets me is that 4"is 4x the area as 2" .
So is it not the equivalent of 4 x 2" columns in parallel or side by side ?

If a 2" column can run with 2kw , then 4 of these would use a total of 8kw .

If each column can produce say 95% without flooding @ say 1l/hr then surely four in parallel would be producing a combined output of 4l/hr @ 95% .

So why is it when we take away the pipes and combine 4 x 2" columns into one 4" column , that it all turns to shit and floods and makes low abv and needs to be taller and need different size packing ?????