Twin Column VM still

[TheMechwarrior]

Too late for data analysis I'm of to bed. Gut feel is twin versus single column results in no significant difference in overall run time. There was however a LOT of differences in the operation of the VM still in dual column mode. Basically the gate valve is redundant, all you need is on/off control here.
In single column I ran the gate valve at ~20% open. In dual column mode I had to fully open the gate valve AND lift the reflux condenses 90mm or 50% out :scared-eek: .

I tried lifting the condensers and restricting coolant flow, nothing I tried would increase my volumetric output.

Run details on the morrow, time for sleep now.

PS I should add that the heating element used in my previous run was 2.4kW and the borrowed element was 2.2kW so another variable to throw in to the mix.

Cheers,

Mech.

[Kimbo]

Too late for data analysis I'm of to bed. Gut feel is twin versus single column results in no significant difference in overall run time. There was however a LOT of differences in the operation of the VM still in dual column mode. Basically the gate valve is redundant, all you need is on/off control here.
In single column I ran the gate valve at ~20% open. In dual column mode I had to fully open the gate valve AND lift the reflux condenses 90mm or 50% out :scared-eek: .

I tried lifting the condensers and restricting coolant flow, nothing I tried would increase my volumetric output.

Run details on the morrow, time for sleep now.

PS I should add that the heating element used in my previous run was 2.4kW and the borrowed element was 2.2kW so another variable to throw in to the mix.

Cheers,

Mech.

I think you hit the nail on the head there mech, with the extra column, you will need extra power because the vapour speed will now be halved. It's the same effect if you just increased the column diameter.
I would put in an additional element..... Possibly on a controller. ;-)

[zombie]

That is exactly what I have just been learning. Vapor speed is directly proportional to input power. If your rig was running on full element power for one column you would have to double that power when adding double the column area to maintain the same vapor speed in each.

Just throw some more money at it, and all is well. Just like women. (mine anyway) :romance-kisscheek:

[SBB]

That top one looks like it leaves a LOT to be desired even for short term use.

[TheMechwarrior]

And the results are in folks, if you compare the 2 runs you can see the overall collection rate is damn near identical at 35mL/min overall.
What I've worked out since and what I should have done initially was a simple calculation, if I want double what my 2" still delivers (output rate) then I need 2 columns (tick) and 2 x 2400W (Doh).
I can hear some out there thinking "Man just go 3inch, simpler", the twin 2" column is a cheaper path for me to take as I already have all the 2" bits to make this happen.

So, I'll be buying 2 new heating elements from FSD to power this baby. I have access to a second circuit nearby so I can spread out the love.

Stay tuned folks, this aint over yet ;-)

Results of single column versus twin column VM still.
In the top run you can see I missed the start of the tails, was chatting to a mate.
Basically with my setup the moment the vapour temp goes 0.1oC above stable I know to start changing jars!


Cheers,

Mech.

[zombie]

Like the "stick to it" attitude.
On a side note... What software did you use for those pretty charts? That is real nice for posting results.

One other... The Picts you posted (f your rig) are real dark, and maybe I am the only one but I really can't see what you have done. Could you please post some other Picts?
Thanks for sharing it.

[TheMechwarrior]

I used Microsoft Excel for the brewlog mate. :handgestures-thumbupleft:

The pics are a little dark, sorry about that. Shitty old camera/phone. I'll take some better pics with a decent camera tonight if I get a chance.

What I've learnt here is: :-B
1. Clearly there was no bottleneck in existing single column
2. Therefore adding a second column resulted in no reduction in run-time
3. Increasing the available column volume from 2.43L to 4.83L or the equivalent of a 2.83" column resulted in a drop in vapour speed
4. Increasing column size without increasing power changes nothing
5. To cut my run times in half I need double the boiler power and a column(s) that can handle it. Not forgetting the cooling water side of things.

[Yummyrum]

Mech ...how did the separation of fores and heads seen to br compared to a single column.
Just wondering here about the smearing issue brought up due to possable variations between the two columns due to packing , reflux ratio differences ?.

[TheMechwarrior]

Yummy,

I'll test the jars out tonight and let you know.

I've been running the single and double column VM like a dumb fire missile, fire and forget!
I ran it 2200W from start to finish.

Just an update for folks following this thread...
1. I've ordered 2 x 2400W heating elements
2. I'm modifying my keg to accommodate the new elements - no drain line at this time.
3. I've ordered a few 3" tri-seal components as I have a 1500mm and 300mm section of 3" tube arriving today...
4. Twin 2" column VM versus 3" VM column @ 4800W run comparisons to follow :)

Cheers,

Mech.

[TheMechwarrior]

Sorry Yummy,

No grading of the cuts for you tonight, I've come down with a head cold. :teasing-nutkick: :violin:
Good thing I have all this home-made health tonic/elixir right here to see me through to a quick recovery.

PS, 3" stainless arrived today, just waiting on my ferrules, clamps and seals and I'll also have a much larger condenser coil to wind. Find times ahead, I love winding those things, so purdy.

Mech.

[TheMechwarrior]

Mech ...how did the separation of fores and heads seen to br compared to a single column.
Just wondering here about the smearing issue brought up due to possable variations between the two columns due to packing , reflux ratio differences ?.

Just quickly Yummy, my nose cleared up for a bit last night so I got a chance to grade the cuts.
Jars 1 through 5 had decreasing levels of heads
Jars 6 though 10 were hearts
Jars 11 through 14 were increasing levels of tails.

So out of 7.7L I had 3.3L hearts.
Heads and tails evenly split either side.

My sampling during the prior single column run was not superb so I can't really compare the 2 in terms of cuts.

I'll do another single column run soon and slow my vapour rate down to the "optimum 12-18" (~half power) and see what difference this makes to the amount of heads/hearts/tails.

Cheers,

Mech.

[TheMechwarrior]

Ah, that was a nice trip down memory lane.

I think it's time to build a new dedicated neutral setup.
I still have the 3" column sitting here doing nothing so it makes sense to use it even though I'd like to try a 4" solution.
The biggest issues really are just the source/type and amount of packing and the reflux condensers.

Even though once set you never have to touch the gate valve on a VM it's a pain in the arse needing a ladder to make adjustments between full reflux and product mode.
With that in mind I'm liking the valveless VM and condenser controlled VM concepts.

I'm travelling for the next few days so while I'm away I'll sketch it all up and see what it looks like on my return Sunday.

If proceeding I'll start a new build log for it.

Cheers for now.

Mech.

[WTDist]

interesting thread.

look forward to the new one :handgestures-thumbupleft: