Building a 2" VM Still in SS, thoughts about design

[vman]

Hi everybody! Been reading here for awhile now, and i am finally starting on building my very own VM Still.
Been researching a bit, but need some sort of confirmation on my design before i start up building!
First image: The whole still :


Head:



I have also seen on a Norwegian forum that some put another ring ing the column. Under the outlet. Like this:


Any thoughts about this?
Any feedback and comments are good
Planning on taking some pictures along the way of production. Have my hands on a 300 L SS heater tank that i`m going to cut up and weld togeher soon, the still connection is going to be a "quick" connection for easy access. Also going to add tubes in the tank for easy internal washing after coocking
As packing i am going to use SS scrubbers.

[astrangebrew]

Hey Vman,

You didn’t say the tube diameter (or I missed it) Judging from the other dimensions I assume 50mm. If so, you are somewhat over powered (your vapour velocity will be too fast) - if you are thinking 75mm – OK but you might want to consider a bit more column height. Really depends what you want to do.
The second ring is most likely intended as a “turbulator” (not the only way to do it). It converts the laminar flow to turbulent flow which improves the vapour split at the upstream “T”.

Cheers
SB

[astrangebrew]

OK MY BAD I didn't look at the title

[new_moonshiner]

the 120 cm is = to almost 4 feet of packing if im reading this right .. which would do the job . I would exchange the SS scrubbers for Copper ones though , ( not copper plated) or better still i would use mesh packing rolled up nice and uniform .. But thats just me .

[The Baker]

Would it be better (and this is not a suggestion, I really would like an answer from someone who knows more about VM stills and stills in general than I do);
would it be better to have the outlet tube a bit bigger? Say inch-and-a-half?
And if so would it be best for the tap and the tube after the tap to be inch-and-a-half too, or could you reduce the diameter to inch, just before the tap?

I have a pot still at the moment and it is a real challenge to use it well; but I am thinking about a reflux still for making vodka from feints and unsucessful batches, and maybe from sugar ferments for liqueurs and schnapps.
It seems that a VM still is pretty much thought of now as the most efficient of the simpler reflux stills; would anyone have other thoughts on that?

Thanks for your simple and clear drawing, too, that's really helpful.

[HookLine]

I don't think you would need both centring collars, just the bottom one.

Would it be better (and this is not a suggestion, I really would like an answer from someone who knows more about VM stills and stills in general than I do);
would it be better to have the outlet tube a bit bigger? Say inch-and-a-half?
And if so would it be best for the tap and the tube after the tap to be inch-and-a-half too, or could you reduce the diameter to inch, just before the tap?

I have a 2' column, with a 1" take-off port, that reduces straight away down to 3/4", and I get good take-off rates. Going bigger (1.5") is certainly not going to be a problem, except it will cost a little more.

[The Baker]

I don't think you would need both centring collars, just the bottom one.

Would it be better (and this is not a suggestion, I really would like an answer from someone who knows more about VM stills and stills in general than I do);
would it be better to have the outlet tube a bit bigger? Say inch-and-a-half?
And if so would it be best for the tap and the tube after the tap to be inch-and-a-half too, or could you reduce the diameter to inch, just before the tap?

I have a 2' column, with a 1" take-off port, that reduces straight away down to 3/4", and I get good take-off rates. Going bigger (1.5") is certainly not going to be a problem, except it will cost a little more.

Thanks, hook.
Do you think the bigger takeoff would give much or any advantage? If so I would check out the different costs and if it seemed worthwhile I might get the biger one.

[plonker]

Hi baker, FWIW, I have been using 1 1/2 inch take off, from a 2 inch column and 1 1/2 inch after the gate. I find its a little too big, and tends to get a bit of a surge from the collasping vapour when it hits the liebig. I am currently converting it to a 1 inch take off and 1 inch after the gate..

[vman]

Started on the tank today. Cut of a piece of a 300L tank and welded together the piece with a flat plate on the bottom, volume on the new tank is about 65L.
I also welded on connections for the heater element, and for drain connection.
The element consist of "two" elements. One 2kW and one 1kW.
Planning on running the still with 2kW and using the second one for heating up.
You guys thing 2kW is about right for my column? I surely think 1kW is too litle?
I also found the pipe that i am going to use for my column. Its 2" SS. Still going for the 1" outlet, and 1" after the valve, to the 90 bend.

Thanks for the feedback!
Going to just weld in the lower sentering ring in my column, and drop the top one.
Also planning on making a bushing in peek at the top of my column, to center the cooling coil.
Forgot to take pictures today, sorry for that. But will take some tomorrow, when i start on the column!

EDIT: Just woundering how accurate the thermometer has to be? The one i have bought now just show whole degres, thinking about bying another one
and put on the outside of the column, under the insulation, what to do think about that?

[HookLine]

Few more comments:

Make sure the packing does not touch the bottom of the centring collar, leave 30 mm or so clearance between them.

Leave 4-5 cm between the bottom of the coil condenser and the top of the take off port.

35 cm for the overall coil length is overkill. Half that length will work very well. 6 mm copper tube is a very efficient heat exchanger. Use the extra space for more packing.

As you probably figured already, one advantage of also using the second centring collar above the take-off port is that it reduces the column to take-off port ratio, which raises the maximum possible flow rate down the take off arm. Which would also make the bigger take-off port & valve of no real value.

I prefer to keep the distance between the column and valve as short as reasonably practical. On mine it is about 110 mm to the centre of the valve.

•••••

Do you think the bigger takeoff would give much or any advantage? If so I would check out the different costs and if it seemed worthwhile I might get the biger one.

It will give you a faster maximum take-off rate, i.e. with the valve wide open during normal VM operation. But on mine the 3/4" gate valve is only opened about a third, maximum, during a run, and I get above a litre an hour of nice clean stuff.

Hi baker, FWIW, I have been using 1 1/2 inch take off, from a 2 inch column and 1 1/2 inch after the gate. I find its a little too big, and tends to get a bit of a surge from the collasping vapour when it hits the liebig. I am currently converting it to a 1 inch take off and 1 inch after the gate.

That's interesting. Let us know how that mod turns out. Might be worth trying to reduce it after the gate first, see if that fixes it.

One disadvantage of going bigger is that bigger valves and fittings cost more, sometimes quite a bit more.

•••••

The element consist of "two" elements. One 2kW and one 1kW.
Planning on running the still with 2kW and using the second one for heating up.
You guys thing 2kW is about right for my column? I surely think 1kW is too litle?

A little slow. I run around 1400 w for a 2" column. Some run faster, some run slower. I can get over a litre an hour.

Also planning on making a bushing in peek at the top of my column, to center the cooling coil.

If you have a centring collar you do not need to worry so much about that, though it should improve he effectiveness of the coil condenser a bit. Only reason I ever centred mine were to get the condensate back to the centre as much as possible.

Just woundering how accurate the thermometer has to be? The one i have bought now just show whole degres, thinking about bying another one

Get one that reads in tenths of a degree.

[vman]

Hi. Thanks for your reply!
But unfortunately it's a little late.
The coil is already made, and the column is welded
Welded in just the lower centring collar. and with some clearance to the collar i get a total packing height of about 110-115 cm. Hope it`s enough for my 2kW element !?

I will have to get another thermometer thats more finely tuned, is it okay to just have it against the outer wall off the pipe under the insulation? is that accurate enough?

The bushings is also made already so

Here's some pictures:


The tank: Going to weld on some adjustable feet soon.

[astrangebrew]

Hi Vman,

The aussies are going to get all over you on the size of your picture files (they get shafted on the size of download files & it really costs them) Try to keep them around 100K. See if you can resize them or maybe a moderator could help

What material did you use for the spacers and cap on that nice reflux coil? (great winding job). Nice welding too!

Cheers
SB

[vman]

Oh, sorry bout that! Will resize them when i get home
The material i used for the spacers and cap is called PEEK

Thanks!
Hoping to get some feedback on my packing height/heat input soon

The liebig cooler and down pipe is going to be connected by a gyrolok connection for easy assembly/deassembly

[HookLine]

The material i used for the spacers and cap is called PEEK

Do you have some good safety data on that material for use with high temp, high strength ethanol? If not, then it cannot be considered safe, until otherwise proven.

You can just use small diameter copper capillary tubing (3mm or so, from air con parts stores), or small flat copper tabs, around the outside of the main coils to keep coils centred.

Otherwise, looking good.

[vman]

No problem to use peek in contact with chemicals!
We use this at work all the time, at wery high temps and in conctact with much worse things than ethanol.

In my attachment you can see that peek is set as resistant to Ethanol | 96%

My first run wil probably be next weekend.
Going to weld up the final pieces after this weekend.

[rad14701]

That chart gives a much better overview than the MSDS does... As long as it is as resistant to vapor as it is for liquid then it should alright... Gonna keep a copy of that chart handy...

[HookLine]

vman

According to the otherwise good chart you linked to there is no data on the compatibility of PEEK with ethyl acetate, methanol, isopropanol, and propanol, all of which are present in the alcohol distillation process, to some degree.

Furthermore, while they give data for 96% ethanol, they do not give the temperature ranges these data are valid for, an important factor in our application. Nor do they give the concentrations the data are valid for ethyl acetate, methanol, and propanol (though this is unlikely to be a problem as these chemicals are usually only found in small concentrations in beverage alcohol distillation).

And of course they cover their arses by stating that:

The reader is cautioned, however, that Curbell Plastics, Inc. cannot guarantee the accuracy or
completeness of this information, and it is the customer’s responsibility to determine the suitability of specific products in any given application.

[vman]

You are a hard man to convince HookLine!
Here`s another chart that contains ethyl acetate, methanol, isopropanol, and propanol.
Is states it`s resistance at only at 20 degrees. But i cannot find any chart that goes over.
But as i previously said PEEK is a well known material, and we use it much at work!
Seeing that it`s resistant to all these gasses at 200°C i think it will cope with some
Ethanol just fine

Sulphur dioxide gas 200 °C (420 °F) A
Hydrogen sulphide gas 200 °C (420 °F) A
Carbon monoxide gas 200 °C (420 °F) A
Ammonia gas 200 °C (420 °F) A
Methane 200 °C (420 °F) A
Sodium hydroxide solution 200 °C (420 °F) A
Phosphoric acid (50%) 200 °C (420 °F) A
Ethylene glycol (50%) 140 °C (284 °F)

[HookLine]

You are a hard man to convince HookLine!
Here`s another chart that contains ethyl acetate, methanol, isopropanol, and propanol.
Is states it`s resistance at only at 20 degrees. But i cannot find any chart that goes over.
But as i previously said PEEK is a well known material, and we use it much at work!
Seeing that it`s resistant to all these gasses at 200°C i think it will cope with some
Ethanol just fine

More complicated than that. A material may be able to cope with a wide range of different potential solvents and temperatures, but that does not tell you if it is okay for high strength, high temp ethanol.

For example, PTFE is practically inert against a huge range of substances. But don't use it with halogens.

You need test results for the specific material/solvent interaction.

[vman]

The finished column and tank

First test run is probably going to be on friday..
The column is to be insulated off course

Sorry for the bad quality pictures. Taken with my phone..

[HookLine]

Looking good.

[vman]

Thanks!
Going to put up some more hq pictures of the parts/welds as soon as i get it fully assemled at home.


When it comes to firing it up, i am a bit unsecure.
Planning to try and follow this guide
http://homedistiller.org/forum/viewtopi ... 07&start=0

Hope it`s the correct way ?
And is it sufficient to insulate the column up to the outtake, and then out to the valve? Or do i need to insulate
after the valve also?

The packing i am going to use:

[vman]

Just tested the packing with a magnet, and it was magnetic
Altho is said SS at the wrapping. What could it be? Safe to use?

[rad14701]

Just tested the packing with a magnet, and it was magnetic
Altho is said SS at the wrapping. What could it be? Safe to use?

My SS scrubbers are also magnetic but haven't discolored after about two years of use... They looked identical to yours when new...

[HookLine]

Even 'non-magnetic' stainless can become a bit magnetic when worked/machined. Sit one of the scrubbers half in/half out of a dish of plain water. Leave for a few days. If there is no rust, then it is almost certainly stainless.

Chances are there is nothing wrong with your scrubbers.

[vman]

Thanks!
They are stainless indeed, tested at work. Have now bought quite a lot of them

[vman]

Tested the still this weekend, and it worked great!
The good stuff came at 77.2 Degrees about 4 cm off the column,
It did not smell anything, and tested it to 95% at 20 degrees!

So all in all i am very pleased with the column, just thinking about stuff to make it even better now!
After the picture was taken, i also insulated the whole way down to the boiler.

[HookLine]

Congrats. That one looks like a keeper. May there be many more successful runs with it.

Gonna build a separate pot still head for the boiler and try some flavoured runs? (Even if you don't do flavoured spirits, a simple pot head is still very useful for stripping your sugar washes.)

[plonker]

Hey vman, can you list your amounts of heads, hearts and tails for your still? I have noticed a change in my cuts since going from 1 1/2 inch to 1 inch...

Cheers

Plonker

[vman]

Hey vman, can you list your amounts of heads, hearts and tails for your still? I have noticed a change in my cuts since going from 1 1/2 inch to 1 inch...

Cheers
Plonker

Will post after some later runs, as i dont have the exact numbers for this run.
In addition to the Wash i also added some old product from someone else and redistilled it.
But some numbers will come up eventually. The next run will probably be in 14 days or so.

What change did you see?


@HookLine

Thanks!

Yes, i am planning on building a pot still next week, also in stainless. Going to cut up an old CM and make one out of the parts.
But i cant really find some good drawings for a good potstill. Have tried searching, but couldn`t find any drawings..
Looked at the one you rebuilt tho, and it looks nice!

So, i someone could have helped me with finding some good drawings, i would be forever grateful!