VM, CM, and LM confusion

[Prairiepiss]

The take off rates are more dependent on the diameter of the column. But a 2" reflux still making a neutral take off rate should be between 1 and 3 drips a second.

[Greg1234]

What is run time for 10 gal wash for 2 " column ?

[myles]

You could reasonably expect to run a 2" column on 1.5kW @ 0.75 litre/ hour

[Greg1234]

Guys so is that means since 3 inch pipe has double surface area I could expect double output ? Like around 1.5 l/h ? I got keg and Blichmann burner so heat output is not an issue ...

[Prairiepiss]

Close to but not always the case. The 3" will defiantly be faster.

[myles]

Guys so is that means since 3 inch pipe has double surface area I could expect double output ? Like around 1.5 l/h ? I got keg and Blichmann burner so heat output is not an issue ...

Here are some generic guidelines but your individual rig could be faster or slower dependent on how you run it.

2" - 1.5kW - 0.75 litres/hour
3" - 2.5 to 3kW - 2.5 up to 3.8 litres/hour
4" - 4.5 to 5 kW - 4+ litres per hour

These are just for basic, out of the box, scrubbie packed columns.

Not everyone wants ultimate speed. You can run a 3" x 42" scrubbie packed column at just 1 litre per hour if you wants the purest product possible.

[Greg1234]

Thanks myles that is what I was looking for I think now I will have to go to the scrap yard for supplies I think 3 inch is what I will be after ...

[holliday]

Just wondering in a vm setup what valves are appropriate for the line to your take off and is the condenser directly above the column capped? If not how does opening your valve direct the vapor to the take off?

[rad14701]

Just wondering in a vm setup what valves are appropriate for the line to your take off and is the condenser directly above the column capped? If not how does opening your valve direct the vapor to the take off?

If the reflux condenser section is capped it must have a vent hole for safety reasons... If you don't understand how VM works then you should do a bit more research into VM theory here in the forums and the parent site...

[holliday]

I knew capping it was dangerous I just don't understand what makes the vapor go to you liebig instead of just keep cycling through your condenser and back down your column.

[Sparhawk]

Simple fluid mechanics, you have opened a path of lesser resistance. Vapor like liquid is lazy and will take the path of least resistance. There are also some thermodynamic's involved regarding the temperature diference in the take off path, but I dropped that class years ago.

Some of it will still be condensed and sent back down the column continuing the reflux action.

[Prairiepiss]

The alcohol vapor being heavier then the water vapor. Wants to take the takeoff path. And the water vapor continues up to the condenser. So the two like to solitary at the takeoff. That's why many like to reduce the size ay the take off. To aid or help with the split. Along with all kinds of other things. Like path of least resistance.

[RumRunnerGuy]

Great thread, very informative for a rookie

[Rooster Cogburn]

Thanks for this info, as a noob builder, I was confused on these terms also.

[HyperandDrunk]

New guys here with some question regarding the VM-reflux type.

Can I use a 1/4" pipe and valve for the product output or is it to small in diameter?

Does the VM still have a slower output than a water managed still?

Can it theoretically produce constant 95% ABV ethanol '?

Thanks!

[DAD300]

Wow...your reading way back in the archives.

1/4" is too small for anything. Maybe a small reflux coil...but the flow will be minimal.

Go look here for some VM data http://homedistiller.org/forum/viewtopi ... 17&t=41579

A proper VM is the easiest and cheapest to build and will outproduce the volume, of any other at 95% ABV.

[HyperandDrunk]

Wow...your reading way back in the archives.

1/4" is too small for anything. Maybe a small reflux coil...but the flow will be minimal.

Go look here for some VM data http://homedistiller.org/forum/viewtopi ... 17&t=41579

A proper VM is the easiest and cheapest to build and will outproduce the volume, of any other at 95% ABV.

Ah.

Thanks a lot for the information and link. I really do appreciate it!

[shadylane]

I saw your diagram and I like it a lot. I was thinking maybe it would be a good idea to add slanted plates under the condenser on the VM setup. What do you think?

Bokakob - VM Still.jpg

This is a response to a old post.
I'll start by thanking Propaniac for sharing info.
But I couldn't help noticing.
In the image, the bottom slant plate is shown upside down.

[emow54]

Some spiffy CAD drawings would be just the ticket... Did I read somewhere that someone was going to try to make some for the Wiki...??? If so, links to them would work great... Your images do get the point across, however, BW Redneck... I'm sure they'll help folks get their head around the different concepts...

Where's the image of that "scurge" Super Reflux design...???

If someone were to provide a mark-up with diameters, lengths, etc for the columns I would be willing to draft them up in AutoCAD. I would consider it my contribution for others helping my plan it out.

[rad14701]

Some spiffy CAD drawings would be just the ticket... Did I read somewhere that someone was going to try to make some for the Wiki...??? If so, links to them would work great... Your images do get the point across, however, BW Redneck... I'm sure they'll help folks get their head around the different concepts...

Where's the image of that "scurge" Super Reflux design...???

If someone were to provide a mark-up with diameters, lengths, etc for the columns I would be willing to draft them up in AutoCAD. I would consider it my contribution for others helping my plan it out.

This has turned out to be quite the zombie topic... Samohon drew up some very nice examples of various design types several years ago... Unfortunately, he and his talents disappeared a year or two ago without warning and nobody has heard from him since...

[Bushman]

Rad you are right about Samohon, his graphics were the best. Since retiring I did not have access to the photoshop and rendering software I had a work. I have good CAD software at home but it lacks the top market rendering ability. Here is a link to a thread I started on the different reflux operations and parts.
http://homedistiller.org/forum/viewtopi ... 17&t=47262

[emow54]

My offer still stands to draw, detail and even render some images for anyone.

[Bushman]

My offer still stands to draw, detail and even render some images for anyone.

I think that is a nice offer, I have done the same although retired I do not have AutoCAD at home I do have Rhinoceros which is a 3D CAD program that can be saved into almost any platform. I have done some Solid models and then in the software done a roll-out to a 2D cut pattern. It lays it out all but the tabs that need adding.

[Contaminator]

What do call a design where a part of the fully condensed liquid is returned to either the boiler or just below the packing?
Are there flaws to such a design and is it recommended?

[Yummyrum]

Inefficient is the best name I can think of for such a still .
Why spend energy boiling wash if it is simply going to be returned directly back to the boiler to be reboiled again .

Sending reflux back to the boiler via the packing on the other hand , is efficient because something useful results ...the purity of the spirit is raised as it climbs up the packing .

And as purity increases , so does the separating of various fractions increase . This means we can remove the foreshots , heads and hearts then tails consecutively in more defined amounts compared to if we had no reflux action happening in the packing .

[Contaminator]

Interesting answer. I still protest !! lol. Sending condenced spirit below the packing should in my mind increase the separation.
Think of it. Plates or rather trays uses a floodbed in order to cool each drip before it all turns into vapour for the next level. I'm thinking that the internal reflux within a packed column could further be enhanced. You are most probably right about the boiler. I now see how meaningless it would be. Doing everything over again for no apparent reason. But sending it into a bubble cap tray below the flood line , straight into the liquid and then have packing above should help separate water faster. At least I will test and compare. Anything for re search.

[bluefish_dist]

You need the returned spirit to make a reflux still work. The liquid coming down the column provides a cooling effect on the raising spirit. That heat transfer from hot vapor to cold liquid helps establish the temperature gradient necessary for separation.

If you return that liquid below the packing or plates, the still would act more like a packed column on a pot still. There would be nothing to cool the raising vapor other than the ambient cooling of the column. If the column had plates they probably would not even load.

The short answer is it wouldn’t work very well if at all as a reflux still.

[Contaminator]

Thank you. I now see how the temp inside the column os more important. It was a good answer

[luva69r]

What type is this Still, if the column is packed and the off-take is controlled by a ball valve with a restrictor that only allows for 2 drips per second on a spirit run?

[Saltbush Bill]

LM " Liquid Management. The amount/speed of the spirit leaving the still is being managed /controlled .. in turn that dictates how much spirit is being refluxed..or in other words how much reflux there is....or another way ...what the reflux Ratio is.
Most LM reflux stills use a needle valve to restrict or increase spirit flow. The type in the diagram uses a restricter nozzle arrangement. I'm told they come with 2 different interchangeable sized nozzles.
Ive never personally run that exact still, but I'm told that for a small commercially available refux still they are one of the better ones.
Not good for Brown spirits but fine for vodka / neutral style drinks.