Twin Column VM still

[TheMechwarrior]

That price is dirt cheap where I come from:
1. 3 part ball valve kit - easy on spares
2. Ferrule/NPT/BSP end included
3. Sanitary design
4. PTFE seals
5. Flush fitting
6. Stainless 304 or 316 options
7. Option to mount an actuator

I could have gone for a 2" through hull option but that option was going to cost a lot more using local supplies.
If you know of a cheaper place to buy sanitary tank bottom valves please let me know.

As far as becoming a trader goes I'm not so sure about the market on that one. The Chinese government are subsidising business postage so anyone in the world can get their hands on cheap parts. The opportunity is in the value adding, putting together kits of proven concepts. That I could see working, for now I'm too busy building up my knowledge about this hobby.

[zombie]

Just found you are correct on the price. http://www.buyfittingsonline.com/3piecefullport.aspx

My cost 107.99 + shipping It just looked high cause I didn't read... 2"

[Sam.]

Seeming no one else has brought it up, are you planning on running both columns exactly the same to take off from the one output?

If this is the case are you plumbing both RC's the same so they have the same flow at the same temp?

Also unless both columns have the exact same packing they will act differently, if you have one delivering more reflux than the other you may find it harder to determine your cuts due to smearing. Also if they aren't both perfectly matched opening the valve will affect them both at different rates.

My thoughts anyway

[TheMechwarrior]

Both columns are identical, height, packing etc. As much as humanly possibly anyway. Both columns share a common vapour off-take. So with the one gate valve closed both columns will equilibrate. Reflux control is going to a little trickyer using a single reflux coil for each with differences in coil inlet and outlet flows etc.

Might be better to join the reflux heads of the column via a shotgun?

Still keen to try it as is, but your point about potential variability is noted. My supplies will be here next week so I will report the results then.

[zombie]

Both columns are identical, height, packing etc. As much as humanly possibly anyway. Both columns share a common vapour off-take. So with the one gate valve closed both columns will equilibrate. Reflux control is going to a little trickyer using a single reflux coil for each with differences in coil inlet and outlet flows etc.

Might be better to join the reflux heads of the column via a shotgun?

Still keen to try it as is, but your point about potential variability is noted. My supplies will be here next week so I will report the results then.

Single shotgun is where I thought you were going. That makes the most sense. Even if there are slight differences that should negate as the columns are running I would think.

[TheMechwarrior]

Thanks for the reply.

On my drive home tonight I considered the single condenser and thought it might create more problems than it solves.
I would then need to ensure I returned an equal volume of condensate back to each column, not sure how easy that would be compared to the other option of running 2 dedicated reflux condensers.

[zombie]

That's why you have all the legos, and I'm playing with sticks, and rocks.
You're right.

[TheMechwarrior]

Funniest zombie ever!
I haven't completely dismissed the idea, just pondering the complexities and looking for ways to make it work. Ideas are a plenty.

[zombie]

I know all about ideas a plenty... My brain case is like a chips ahoy bag.

[Sam.]

You could buy or build a 3 inch column and solve all your problems :handgestures-thumbupleft:

[Yummyrum]

You could buy or build a 3 inch column and solve all your problems :handgestures-thumbupleft:

Sam ,
Where's the challenge in that :laughing-rolling:

[Sam.]

You could buy or build a 3 inch column and solve all your problems :handgestures-thumbupleft:

Sam ,
Where's the challenge in that :laughing-rolling:

There is probably a reason most people run a single column ;-)

Be interesting to see how this runs when complete tho :handgestures-thumbupleft:

[zombie]

How about a simple plate to control/divert each columns reflux.

[TheMechwarrior]

Right enough banter, she's getting a run today! Will post a pic of the setup just as soon as its ready.

[TheMechwarrior]

Zombie, a lot like what I had in mind! It's a similar solution employed on multi effect falling film evaporator. Off to cleanin and buildin I go :)

[zombie]

Yeah cool. A multi falling effectulator. That's what I meant.

Serious tho I can't wait to see your results. Especially your take off rate. I would think it may trick you into running slower than needed.
Full speed ahead Clark! Damn the torpedoes.

[TheMechwarrior]

caboom!...smoke and darkness...

Slight delay folks as I pull it all apart and drain the leg and replace the blown old style keg king heating element. I only got 4 runs out of it. Borrowed a newer model from a mate. I'll be ordering a FSD heater tonight.

[TheMechwarrior]

Just as the twin columns reached temp and went into full reflux I found my bottom 2" seal leaking :(. Power off while I let it cool a little so I can fix my fancy screen mesh 2" seal. Looks like I'm in for a long night.

[Yummyrum]

Let the force be with you .....all this bad shit must mean it will be a good result...hows that for logic ....power on Mech :handgestures-thumbupleft:

[TheMechwarrior]

I love your attitude!

With my newly found downtime I'll provide everyone with some photo and detail updates. A the end of this exercise if it works I'll provide a simplified build version as this was jury rigged for proof of concept.

So...I now have 3 cooling loops my pump needs to manage.
They are all connected in a counter-current series, with cooling inlet at the base of the Liebig and out in to the new second reflux condenser and finally on to the original column reflux condenser. This final condenser has a temperature probe attached.

Cooling water flow in/out of the system is 1L/min in this configuration.

Album link for full sized images: https://imageshack.com/a/ARAq/1

First delay, heating element went pop:
Old style KK element at the top and the new style at the bottom, both leave a bit to be desired for long term use.


Second delay, needed a new (180mm) reflux coil for the second column
And here she is :D


Here she is in operation:
Full size link: http://imageshack.com/a/img822/2886/z7z3.jpg


Another angle:
Full size link: http://imageshack.com/a/img40/6700/gkec.jpg


Cheers for now,

Mech.