Movable Coiled Dephlegmator Column Control

[DAD300]

halfbaked and I shared a moment the other day where we discussed this concept. That and another post/conversation about the impossibility of getting a true 50/50 (reflux vs takeoff) split from the Condenser Controlled VM made me want a dephlegmator/CM Still. But just for an instant.

We use the term Reflux Condenser to mean a condenser that returns 100% of all the vapor that engages it. i.e. the reflux condenser in a LM or VM design.

A Dephlegmator is a device arranged for the partial condensation of a vapor stream. The vapor stream flows vertically upwards through the Dephlegmator and the condensate (condensed vapor) runs back down under the influence of gravity. The vapor stream and condensate thus move countercurrently and are in direct contact with each other.

My desire for a dephlegmator passed when I realized their pitfalls. The traditional dephlegmator inhibits the total volume of the vapor flow. Example: a 4" dia column with a 4" dia dephleg on top has a number of small pipes reducing the vapor flow cross section. So, with the dephlegmator turned off, you still have a vapor restriction. At best it speeds the vapor passing through it and makes it harder for the Product Condenser to cope.

The BIG idea being this would work on a plated or packed column with less fabrication. I could also see it conserving water, as I could dial in just enough water to get 100% reflux more accurately than the Condenser Controlled VM.

So, the drawing below, makes for a movable dephlegmator. Not only can you control the water flow through it for a partial condensation, but you could move it in & out of the vapor path while changing the water flow. Allowing for less than a 50% reflux and less speeding of the vapor.

[heartcut]

Good concept. Might consider having the dephlegmator vertical with the takeoff on the branch.

[googe]

Wouldn't you still get some reflux, the passing vapor would brush past the end of the coil, and/or the coil would cool the out tube/ tee section?. I'd imagine you might get some small pooling to, a slight angel might help?. Is the vapor speeding up on a standard deflag the main reason you thought of this.

[heartcut]

It's like Manu's concept. The thing that caught me is, with the condensor vertical and adjustable, you could pull it up for a reflux coil or lower it into the vapor path for a dephlegmator. My coiled dephlegmator is adjustable, but not that far. Hmmm.

[DAD300]

heartcut, that would be the normal config for a Condenser Controlled VM...I have been running that for years, see the link in my sig block. But some have questioned the ability of the CC VM to get to a 1:1 reflux ratio. This could get less than a 1:1.

Also, if the dephleg is in above the vapor path, fixed you can never get it completely out of the vapor path.

Yes, it's another Condenser Controlled still design, using Cooling Management like a normal dephlegmator over a platted still.

This gives you the option of removing all or part of the vapor congestion. You could run it at 100% reflux, reduce water flow for any percentage to zero, remove it from the vapor path for zero reflux and no vapor speed increase!

Want to reconfig as a pot still with no induced reflux? Want to do it during a run? Turn the water off and move the coil out of vapor path in seconds.

It the water is turned down to zero, there would be no condensing going on even if the coil is left in the vapor path.

Yes, in this drawing there could be some pooling if the coil is moved into a true 90 deg elbow. Some angle would stop that or a plate on the end of the coil...

Years ago I saw something similar in a "Y" config, but the coil was not movable. One branch the takeoff and one the reflux coil. It was an attempt to get a true 1:1 reflux ratio. Then the added a vapor valve to divert the vapor to either branch of the "Y".

[heartcut]

DAD, can your VM coil be adjusted so it's completely below the takeoff?

[DAD300]

Yes, in the CC VM the reflux coil attains 100% reflux with no physical valve.

This coil will also.

[bellybuster]

You would need a cap attached to the coil or the vapour will just go past the coil and out when the waters turned off instead of thru the product condenser.
I have a similar idea rolling around but need to mess some morebefore revealing.

[DAD300]

Yes, a cap in the "T" could serve as an adjustment point allowing you to screw the coil in and out and serve as the vapor barrier.

[acfixer69]

The Y concept was a great idea by Decoy (I think) I don't think he ever built it though. Can't wait to see how this turns out Dad.

That was Manu di Hanoi. He manufactures them and are a proven winner. http://www.youtube.com/watch?v=2vJn0lp-IP0" onclick="window.open(this.href);return false;" rel="nofollow

AC

[heartcut]

A cap on the T with threaded in compression fittings and teflon ferrules works well, easy to adjust and the coil stays where it's put. Teaches you not to tug on the hot tube, too.

[bellybuster]

I love these threads because I want to rebuild my Nixon Stone into something a bit more versatile. However, I'm failing to see the benefit over the other condenser controlled still you already put together. Unless close to zero reflux is the benefit. True pot still mode.

[DAD300]

bellybuster... I think there are two benefits. You could go to pot still mode just by turning off the water and the adjustment would be on the side and more reachable for some with tall columns.

The Movable Coiled Dephlegmator will not only reach 100% reflux with min water flow (I think the tube dephleg comparison proves that), it can be finely adjusted to zero reflux, while running. And I think it will improve the capabilities of any existing Product Condenser by keeping vapor speed down.

I'll beat an old drum...I can make this dephlegmator from SS Flex pipe and a "T" in a few minutes. The fabrication of this dephleg is as simple as it can get. I see someone putting this over a plated column soon!

I won't change my CC VM. In fact I'm just finishing a 4"x 40" "E" sized SPP packed version. I love the simplicity of it. But I thought this concept might show the value or explain the CC VM better.

And it might add value to someone else's design. Like a super simple plate...with a super simple dephleg over it.

[googe]

How is it sealed when it's slid out of the vapor path?, I mean, how do you slide it in and out in a sealed section?.

[Hound Dog]

DAD, instead of moving the condenser in the T, wouldn't it be easier to just put a valve on it and control the coolant flow going through it? Making it a CM? Shut off the coolant and, Bingo, pot still mode.

[DAD300]

Hound Dog, Yes it is meant to have a vale for coolant flow like a fixed dephleg, but also to be movable to get it out of the vapor path, either partially or completely.

If there is minimal water flow and it is moved back, the seal won't need to be air tight, just vapor tight. Like the top of a normal reflux coil doesn't have to be sealed on an LM or VM. Envision a PTFE flexible gasket at the rear of the coil.

[Prairiepiss]

I would say that you would want the condenser tube angled up a bit. So that any condensation on the coils. Would run back to the column.

[Hound Dog]

Hound Dog, Yes it is meant to have a vale for coolant flow like a fixed dephleg, but also to be movable to get it out of the vapor path, either partially or completely.

If there is minimal water flow and it is moved back, the seal won't need to be air tight, just vapor tight. Like the top of a normal reflux coil doesn't have to be sealed on an LM or VM. Envision a PTFE flexible gasket at the rear of the coil.

Yes, I guess you're right, its not that hard really. Much PTFE material has come down in price these days too. Like I use a solid chunk of it threaded into a fitting and drilled out to hold my thermometer probe. You could make it snug to your tubing and it will still slide. Its not like Teflon is known for being sticky.

[googe]

You'd have to make one and try it dad, to get a true feeling of if it would work better, and compare to your normal deflag. how it runs, take off differences, build time and skill level ect ect. Like these new ideas, keeps this hobby moving!.