Column height vs. packing

[shadylane]

Curious, why would you prefer a CM with running water? Aren't CM stills more stably operated using a low pressure water pump in comparison to well water for instance? I know many use water pressure regulators too. I figured a CM would be better suited if one had to recirculate water. Well pumps kick on & off often which plays hell with providing consistent water flow & pressure.

Let me rephrase that.
When I said running water, I was thinking Municiple water that was of constant temp and pressure.

[Salt Must Flow]

Curious, why would you prefer a CM with running water? Aren't CM stills more stably operated using a low pressure water pump in comparison to well water for instance? I know many use water pressure regulators too. I figured a CM would be better suited if one had to recirculate water. Well pumps kick on & off often which plays hell with providing consistent water flow & pressure.

Let me rephrase that.
When I said running water, I was thinking Municiple water that was of constant temp and pressure.

Ahhh city water. That makes more sense. Do CM stills use less water during a run than other stills? I imagine they might, but marginally so. VM still has advantages over other designs.

[Renhoekk]

I gave that a try awhile back just to see what happened.
A tall empty glass column didn't do nothing.
And the same column with a defleg was like driving with the brakes on.

I’m kinda jealous you had a big glass column to play with. Some people relax by watching fish swim in a tank; I like to watch ethanol-water vapor dance

[shadylane]

I’m kinda jealous you had a big glass column to play with. Some people relax by watching fish swim in a tank; I like to watch ethanol-water vapor dance

Here's a link to one of my glass column builds.
viewtopic.php?t=78254

[shadylane]

Do CM stills use less water during a run than other stills? I imagine they might, but marginally so. VM still has advantages over other designs.

Ya a CM uses the least water of all the other designs.
A CM still head can also be made shorter than the other options.
That leaves room for a longer column before you have to start cutting holes in the ceiling.
If I was making neutral only, I think a LM would be a good choice.

[rockymars]

My 2 cents worth.
The scoria that looks like black glass with bubble holes, works better than the red soft stuff.
Get a big bag and sort through it.

I believe it is the black stuff. I’m still fancying the idea of laying in with a hammer, sounds like more fun

[rockymars]

Don't make up your mind too fast.
A lot depends on the cooling water source, if you have running water then I'd prefer a CM.
If you are limited to using recirculated water, then a LM, VM or CCVM would be a better option.

I have municipal water at a good pressure, but I don’t want to waste so much. I’ll probably using a recirc system.

[rockymars]

VM stills aren't affected by fluctuating water pressure/flow at all. It actually helps with a VM if the water temp is consistent. If the water starts to heat up (while recirculating), I imagine the flow might eventually need to increase over time with a VM or any other type of still. I put a thermowell in the output of my reflux condenser and I set a temp alarm with a digital thermometer so I can maintain the minimum flow rate to optimize water usage. The flow rate does go up & down, but never exceeds the set temp because I monitor it. Hell I even monitor the exiting water temp to my product condenser just so I know that it is operating in the range I determined.

I was thinking along these lines. I’m a curious bugger so I was going to install thermos, just for kicks. But would also serve a purpose in my cooling system. I was thinking of slowly feeding ice into my recirc system to avoid large temperature swings in the condenser. The thermometer at the condenser outlet will be my guide (and there will be a thermometer in my tank too).

[rockymars]

Ya a CM uses the least water of all the other designs.
A CM still head can also be made shorter than the other options.
That leaves room for a longer column before you have to start cutting holes in the ceiling.
If I was making neutral only, I think a LM would be a good choice.

Good to know and food for though. Ceiling height is actually a limitation in my case. Being in a rental, there won’t be cutting of any ceilings

I’m using a 35L Digiboil for my homebrewing. It’s on the tall side (28”), ceiling height a tad over 93”. Leaving about 4” at the top for cooling water connection and space to work if needed, I’m left with 61” for the entire column, including head. For a 48” column I’ll be left with 13 inches for the head. That sounds a bit low, esp. if I want to push column height up to 5’ as was suggested earlier.

Either CM, horizontal reflux coil, or some kind of offset head, would be needed but I don’t think I’ll get to 5’ either way.

EDIT: above assumes I’m going to operating discreetly indoors. I don’t have a shed or garage, but do have a carport with ample headroom. Will just have to shield my operations from the prying eyes of neighbours, but that makes me nervous.

[StillerBoy]

VM stills aren't affected by fluctuating water pressure/flow at all. It actually helps with a VM if the water temp is consistent.

All reflux column setup are affected by fluctuating water flow, and similarly all reflux column setup are improved operationally with stable inlet water temp..

Fluctuating water flow create a temperature imbalance in the column due to temperature changes of the distillate returning, similarly, so does an inconstant inlet water temp fluctuation..

Mars

[Salt Must Flow]

VM stills aren't affected by fluctuating water pressure/flow at all. It actually helps with a VM if the water temp is consistent.

All reflux column setup are affected by fluctuating water flow, and similarly all reflux column setup are improved operationally with stable inlet water temp..

Fluctuating water flow create a temperature imbalance in the column due to temperature changes of the distillate returning, similarly, so does an inconstant inlet water temp fluctuation..

Mars

Not really. Dephlegmators for instance are totally thrown off by fluctuating flow rate & pressure. CM could be considered similar. VM on the other hand is not affected by common household fluctuations. While monitoring the exiting water temp, I can see that the water temp can rise and drop a bit due to fluctuating flow rate/pressure, but the amount of reflux is not affected. The takeoff rate is not affected. The % ABV is not affected. Other than the small change in water temp, fundamentally the still is not affected.

[Twisted Brick]

VM stills aren't affected by fluctuating water pressure/flow at all. It actually helps with a VM if the water temp is consistent.

All reflux column setup are affected by fluctuating water flow, and similarly all reflux column setup are improved operationally with stable inlet water temp..

Fluctuating water flow create a temperature imbalance in the column due to temperature changes of the distillate returning, similarly, so does an inconstant inlet water temp fluctuation..

Mars

This makes sense given the best tool for regulating coolant flow to a reflux condenser is a needle valve, especially when the condenser is made out of copper.

[StillerBoy]

This makes sense given the best tool for regulating coolant flow to a reflux condenser is a needle valve,

Absolutely.. which why a needle valve is recommenced with flow rate issues, but not for pressure issues as that's totally different.. Unfortunately.. some can't relate to the differences..

Unfortunately not only is there misunderstanding in how a reflux condenser is affected by water flow rate, but the takeoff rate and the ABV thrown in the mix, creating more confusion..

Mars

[Salt Must Flow]

This makes sense given the best tool for regulating coolant flow to a reflux condenser is a needle valve,

Absolutely.. which why a needle valve is recommenced with flow rate issues, but not for pressure issues as that's totally different.. Unfortunately.. some can't relate to the differences..

Unfortunately not only is there misunderstanding in how a reflux condenser is affected by water flow rate, but the takeoff rate and the ABV thrown in the mix, creating more confusion..

Mars

You are entitled to believe what you want, but you have failed to explain how a VM column and it's function is negatively affected by normal fluctuations with a home water system other than your assertion that "fluctuating water flow create a temperature imbalance in the column due to temperature changes of the distillate returning". Causing what exactly to be negatively affected? How significant do you claim this impacts what exits the still? It is undetectable even if your assertion were true.

I wouldn't expect anyone to be stressed to use a water pressure regulator or flow regulator unless they have reasonable evidence to believe not using one will impact the quality of what exits the still or how it functions. As I said, normal fluctuations with water flow/pressure doesn't affect a VM like it does dephlegmators, CM and the like. It's just an observable, repeatable and verifiable fact.

[StillerBoy]

but you have failed to explain how a VM column and it's function is negatively affected by normal fluctuations

Causing what exactly to be negatively affected?

Interesting use of the word "negatively".. Where in my statement posted did I say such.. I merely stated that all reflux column condensers are affected by water flow rate and water inlet temp.. a plain and simple fact..

Also interesting is your use of the word(s) to change the intent of the statement, your a real artist at that..

Mars

[rubberduck71]

I’m using a 35L Digiboil for my homebrewing. It’s on the tall side (28”), ceiling height a tad over 93”. Leaving about 4” at the top for cooling water connection and space to work if needed, I’m left with 61” for the entire column, including head. For a 48” column I’ll be left with 13 inches for the head. That sounds a bit low, esp. if I want to push column height up to 5’ as was suggested earlier.

Rock, I too use a 35L digiboil. Here's a pic with the stainless lid. I added a 2"x3' SS spool & pack it with copper mesh. I actually had enough space to add the copper dome (adds about another foot). Now it's about the same height as me (6'3") where the water lines bend over the cardboard dowel hung by bungee cords from my basement joists.

Stripping runs are 3-4 hrs with 7 gal boiler charge @1500w/120v. Spirit runs with 7 gal can take up to 10 hrs! I use a Brewhaus voltage controller with just the 1000w element ~80v.

[Salt Must Flow]

but you have failed to explain how a VM column and it's function is negatively affected by normal fluctuations

Causing what exactly to be negatively affected?

Interesting use of the word "negatively".. Where in my statement posted did I say such.. I merely stated that all reflux column condensers are affected by water flow rate and water inlet temp.. a plain and simple fact..

Also interesting is your use of the word(s) to change the intent of the statement, your a real artist at that..

Mars

Actually that's you projecting. This was your claim:

fluctuating water flow create a temperature imbalance in the column due to temperature changes of the distillate returning

So as I asked previously ... exactly what were you inferring? It's like pulling teeth to get you to back up your claims. Now you're trying to wiggle out of it by your obfuscation, redirection and trying to change the story.

[shadylane]

VM still has advantages over other designs.

A VM also has some disadvantages compared to a CM or LM.

A VM needs a large valve to control the take off and the reflux condenser is tall.
It doesn't have the ability to be run at low reflux ratios like a CM or LM can.
At best on a VM can only take off half the alcohol and the other half is condensed as reflux.
That's why a VM takeoff isn't used above plates, because the excess reflux would flood the plates.

The reflux condenser for a LM can be mounted almost horizontally is needed.
Last but not least, a LM can be run without a product condenser.

[Yummyrum]

A VM also has some disadvantages compared to a CM or LM.

True , but only if you want to use it as a stripping device ........It's a reflux head , not a Pot still head and can't ever be used as one .

A VM needs a large valve to control the take off and the reflux condenser is tall.

No it doesn't . only when folk try to use it for stripping ....it's not a stripping still. when used as a reflux head , a valve about 1/3 diameter of the head is quite OK .

It doesn't have the ability to be run at low reflux ratios like a CM or LM can.

Correct , but who needs too when making Neutral or using it on 3 or 4 plates to make flavoured stuff .

At best on a VM can only take off half the alcohol and the other half is condensed as reflux.

Correct . that as good as it will do if the valve is the same diameter as the Column .Again , it's not a stripping head so shouldn't be a problem .

That's why a VM takeoff isn't used above plates, because the excess reflux would flood the plates.

Now that makes no sense Shady . I and quite a few others use VM above plates and it works very well . As far as flooding the plates , the same power under full reflux with all heads CM,LM,VM will produce the same amount of reflux .How does a VM flood more easily ?
If it Floods with a VM , it will flood with a CM . Turn the power down .

The reflux condenser for a LM can be mounted almost horizontally is needed.
Last but not least, a LM can be run without a product condenser.

I'll give you those

[shadylane]

... I and quite a few others use VM above plates and it works very well . As far as flooding the plates , the same power under full reflux with all heads CM,LM,VM will produce the same amount of reflux .How does a VM flood more easily ?
If it Floods with a VM , it will flood with a CM . Turn the power down .

A VM takeoff above plates is rarer than hen's teeth or frog's fur.
I don't have to turn the power down on a CM to avoid flooding.
If needed, I can turn the reflux down farther than possible with a VM.

[Yummyrum]

... I and quite a few others use VM above plates and it works very well . As far as flooding the plates , the same power under full reflux with all heads CM,LM,VM will produce the same amount of reflux .How does a VM flood more easily ?
If it Floods with a VM , it will flood with a CM . Turn the power down .

A VM takeoff above plates is rarer than hen's teeth or frog's fur.

OK , I'll accept that Shady I think Me ,Setsumi and Bluefish are a minority .... If there are more of you out there , stand up ..... Please

Shady , for what it's worth , I totally agree with you that a CM or even an LM is more versatile than a VM , but for me , with variable cooling and heating conditions , VM rules



But getting back to the plated still thing , I'm still not sure what you are talking about regarding flooding . I never get flooding in my plated still while I'm doing a run so I find the whole concept a strange point to discuss .

Like sure , if I turn the power up so high that I get flooding , I would have been smearing tails through at about half that power , but it's waaaay above the power I'd normally run my hearts at . So surely you are not talking about during the "normal part of a run .

Are you referring to cranking up the power once the hearts are done to strip out tails ?
Because that's something I don't bother with because I hate the Bastards and prefer to leave them in the boiler .

But then again , If I really wanted to reap those scanty mofos , I'd crank power until I saw a reason not too go any higher . ....... And then maybe I'd wish I had perfect heat and cooling conditions that I could run a CM and crank it a bit higher .

[shadylane]

Are you referring to cranking up the power once the hearts are done to strip out tails ?
Because that's something I don't bother with because I hate the Bastards and prefer to leave them in the boiler

I hate tails also.
I used to waste time trying to extract the most alcohol.
Now adjustments are made to draw off the forshots and heads.
But once the hearts have started, no more changes are made to power or reflux.
I just let the CM do its thing and the output slowly stops, I shut off the power and drain the pot.

We agree mostly, I'm just arguing about the differences for the sake of the argument.
I hate tails enough, that I now always do stripping runs, to get rid of some before I do a spirit run.
That's an advantage to a CM or a well designed LM. It can be used as anything from a potstill to 100% reflux with only the turn of a needle valve.

[StillerBoy]

That's an advantage to a CM or a well designed LM. It can be used as anything from a potstill to 100% reflux with only the turn of a needle valve.

In agreement on that statement..

Both are good, but the LM is my workhorse, especially in hybrid mode for flavor..

Mars

[OtisT]

I just finished a new modular column head and condenser that switches between VM and CM. I feel lucky for getting the best of both worlds. Otis

[bluefish_dist]

CM’s do offer the advantage of 0 to 100% reflux. A VM can’t do that. But I never found I even wanted to run a 1:1 reflux rate. I bought big valves so I could, but usually ran them less than half open. If I wanted a lower proof, I changed the number of plates or inches of packing instead of trying to detune my column using reflux rate.

A VM is limited in size due to having to have a larger take off valve which may not scale as easily as a CM. This is really a non issue at the hobby size. I ran a 2” valve on my 6” column and was able to produce from 130 proof up to 190+ depending on the column/plates I was using. I would argue my VM was no taller than a CM. I used a Thor’s hammer style condenser which added maybe 6” above my takeoff.

Imho a CM requires a more stable water supply than a VM. All the reflux condenser has to do on a VM is condense the vapor. On a CM the flow rate and temperature control your rate of reflux, swings in flow or temp can cause big swings in reflux rate. On a VM the only change would be how far the liquid falls before being reboiled. I doubt most operators would even notice the difference unless there were huge swings in cooling flow or temperature.

In the end, on a hobby level or small commercial, I love the stability of a VM. If I was running a 10-20” column a CM is the only option.

[rockymars]

Rock, I too use a 35L digiboil. Here's a pic with the stainless lid. I added a 2"x3' SS spool & pack it with copper mesh. I actually had enough space to add the copper dome (adds about another foot). Now it's about the same height as me (6'3") where the water lines bend over the cardboard dowel hung by bungee cords from my basement joists.

Stripping runs are 3-4 hrs with 7 gal boiler charge @1500w/120v. Spirit runs with 7 gal can take up to 10 hrs! I use a Brewhaus voltage controller with just the 1000w element ~80v.

Hey rubberduck,
That’s decent numbers you’re getting! The spirit run output is a bit lower than what I’ve seen, but still decent. What sort of ABVs are you getting for your spirit runs?

I bought myself this CM rig, a 20” spool to raise column height, additional copper mesh for packing, and a stainless dome.

Will take ages to arrive from China… Being so modular, it would be easy to convert it to VM, just a few more pieces to purchase once I’ve gotten the hang of this beast. I have more wattage (1900-2400W) at my disposal, but I’m not sure if the shotgun (2”x400mm, 5-tube) will keep up. Only time will tell.

[still_stirrin]

Rocky,

If you really want high purity off your still, ditch the deflag reflux condenser and add a tee with a double coil, or even an concentric condenser on top. Allow your reflux condenser to “do its job” and send any vapors back down the tube. The deflag (shotgun) style will work OK, but whenever worked (as you will with high reflux ratios) it will pass more vapors that you’d prefer returned to the packing.

I suggest looking at the CVVM or even a conventional valved VM design. Bothe work great and regulate the reflux well for a consistent %ABV product off still. CM’s can be tricky to manage to keep the product consistent as it produces.
ss

[howie]

why would you convert it to a VM?
not having a go at any particular style of still, but that CM gives excellent quality product.
especially using a shotgun RC instead of the old cross-thru cooling tubes CM type, the RC uses very little water to achieve full reflux.
when you get used to balancing your rig it will get easy.
once i have set my RC water rate i never have to change it*, i just do small alterations to the power controller if i want to change the output.
i think that the PC shotgun will be ok.
as for for weight, the whole thing gets a bit heavy, especially when refluxing (when both condensers are full of water)
the lid is ok weight wise and will support everything you've got (downward weight)
i just support mine to prevent any sideways flexing, i didn't like the look of it when i had the 4" gin basket on as well

*disclaimer - i have a submersible pump in a 50kL water tank.
other stuff,presuming that's a 2" column?
clark rubber sell pipe insulation, slides on great
https://www.clarkrubber.com.au/products ... 0662319158

[rubberduck71]

Hey rubberduck,
That’s decent numbers you’re getting! The spirit run output is a bit lower than what I’ve seen, but still decent. What sort of ABVs are you getting for your spirit runs?

For whiskeys, it typically starts ~85% & I'll shut it off in the 30-40% range just to collect some tails to add to next batch.
I'm typically making my hearts cut from the jars in 80-85% range, but sometimes I can get decent stuff down to 75 or even 70%. However, all that can vary depending on charge size & what the ratio of low wines/feints/leftover wash that went in.
If I have a full charge (~27L in 35L boiler), I usually get ~4-5L hearts & 5-6L of feints.

I have the kegland reflux head also, but I've only used it 3 times. On my latest rice YLAY run, with a 14L charge, I got 1.9L hearts (~93-94%) + 2.9L feints.

Hope that helps.

[shadylane]

Rocky,

If you really want high purity off your still, ditch the deflag reflux condenser

The column height and packing makes for max purity, not the type of reflux condenser.
Here's how big the coils need on a 4" dephlegmator that can handle 6kw @ 100% reflux.
All you have to do is clamp it on the end of the column and connect the union to the reflux condenser.