Bokakobs slanted plate coloumn

[nimrod77]

Hi guys,
I'm a new hand at all this and I am going to build my own still. I have access to all the equipment you could imagine for metal working at work! Has anyone tried the slanted plate coloumn design by the great Bokakob? Looks interesting as it apears to not need any packing?! Is my assumption correct on this or am I looking at the plans wrong?
If I read the plans correctly you top it with a EL head of bokakobs design aswell....
Any guidance in this would be great. If there are people out there with this still, how does it go? Good purity? No nastyness involved?
Thanks all!!
Nimrod

[Grayson_Stewart]

Looks like a neat toy to build if you want to invest alot of money and time, but I would think it would be near impossible to ever clean out completely if you boiled it over, would be concerned about the pressure build up in case of a blockage, doesn't lend itself to the dual role of pot stilling and nuetral spirits as it would become a reflux collumn by the end of the run, would really hate to have to deal with all those bolts, and with 10 to 15 plate levels you would need at 20 to 30 EL plates soldered in. Those plates aren't a piece of cake to solder unless you have a really good tight fit.

Copper mesh would cost you only about $20 US max, takes about 5 minutes to stuff a collumn full of rolled mesh, can be cleaned with a ten minute soak then a rinse, take 10 seconds to shove the mesh out with a broom handle to be in pot still mode.

An EL head wouldn't be bad at all, I've made and used them. Just depends on what you like for the column.

[Eth&All]

Build the Bokakob Mini-Still instead. It will produce 95% alcohol, is tried-and-true, and is easier to build. Go to Yahoo New Distillers group and look in the files section.

Eth&All

[decoy]

I havent made one yet its going to be my first reflux still.
I think it his idea on an angeld plate still has posibilities here is my modification to his still makeing it a bit easyer make in my opinion
A few guys offerd some intresting sugestions or chnages to make that you can take a look at.

http://homedistiller.org/forum/viewtopic.php?t=1731

[nimrod77]

Thanks for the responces guys.
I have a couple of excelent welders that I can get to do the job for me (amazing what a carton of piss can get you
I was thinking of making the whole thing modular as in the plans, but instead of bolting it together individualy with bots & nuts, I would make some "tie rods" out of rod and run a die over the end. This would hold the entire assy together with only 6 rods & 6 nuts. I guess it might be a big job though....
I was thinking that I may just do the mini still design, with a 1.5m coloumn including the coil. Would a 30cm long double helix coil be big enough for this still with a 1.15 packing height? (5cm for the plate & reflux tube/themometer point).
Thanks again guys
Nimrod
This is the design that I am planning on for the head. Is this the "mini still design that everyone is talking about??

[OldStormy]

Hi Nimrod,
Puzzled as to why you need the overflow tube when the collection plate can do the same job as in the original design. Not suggesting it won't work but why add to the complexity?
Cheers,
OldStormy

[nimrod77]

I'm not 100% sure what I will use for the final design.
This was the one that I found of Bokakobs. I have read that this one was a "more refined" version of his design with the reflux pipe.
Any coments welcome!

P.S I have just been given some 55mm copper pipe to use for the coloumn. Is this a good size to use? How would I work out the HETP's for the plated design above??
Thanks again for the input guys!

[nimrod77]

Hey guys?
Still learning here, do you need to have a hole in the top cap for a vent (where the condensor coil pipes come out of the top of the still) if your not going to put a thermometer in there??
Cheers guys!
Nimrod

P.S. Sorry for all the posts

[OldStormy]

Hi again Nimrod,
The internal overflow pipe as shown in your diagram should turn down to ensure the return condensate falls into the middle of the column. As you have indicated it, a fair amount would travel along the underside of the pipe and run down the inside wall of the column which I gather from others is not the optimum reflux action.
You need the top of the condenser open to stop pressurising the still and going BOOM.
Cheers,
OldStormy

[knuklehead]

OldStormy is right, if it doesn't turn down you will get channeling where the distillant just runs down the wall of the column and not actually through the packing. I think thatis the point of the line to place the dripping reflux. If you relied on the plate to over flow you would have the same problem.

[nimrod77]

Hey all,
How much 1/4" pipe would I need to make the 30cm long double helix condenser that I am planning? Is 10m long enough for the condenser and some left over to make the other fittings??
Cheers all!
Nimrod

P.S. Just looking around, is a 30cm long condeser overkill? would say a 15cm condensor do the same job?
Cheers

[nimrod77]

Anybody?? bueler??

[Grayson_Stewart]

What is the diameter along the centerline of the inner and then the outer coils?

[Guest]

1" id on the inner coil, and 1 3/4" id on the outer coil. Is 15 cm long condensor long enough?
Thanks
Nimrod

[Eth&All]

Nimrod,

You will only need 10' of 1/4" tubing to make a 5" double-helix coil (plenty adequate) for your Mini-still. Please check other recent threads on this topic of how much is needed - and how to wind it. Also go to Yahoo group - New Distillers and in the Files section is a more up-to-date photo and directions provided by the designer himself. Do more research!

[Grayson_Stewart]

3.1415 x 1" = length of one inner coil = 3.14"
3.1415 x 1.75" = length of one outer coil = 5.49"

For a 5" long coil there would be 5"/.25" individual coils, or 20 coils of each.

[20 x 3.14"] + [20 x 5.49"] = 172.6"

172.6" / 12" = 14.38 ft of tubing required.

This does not account for the run of tubing used to reach the inlet and exit water supply.

1" = 2.54 cm

[Guest]

Thanks grayson, Much apreciated.

[OldStormy]

Hi to the experienced guys,
Advice please. I am considering building an eliptical plate still a la Bokakob but am querying the location of the thermometer as shown on his mini still diagram as it is in the column packing. I would have though just below the collection plate but above the packing would have been better, ie. in the vapour.
Comments please.
Cheers,
OldStormy

[jbrew9999]

Yes, put it above the packing but below the first plate. And there has been some talk of avoiding putting it in the path of the dripping reflux so maybe put it off center or less than half way in.

Also I recommend that your head separates from your column so that you have at least a chance at cleaning flux off of the lower plate.

And don't worry about cutting perfect eliptical plates to solder inside of the head. Just cut diagonal slits in the head and slide rectangular plates into the slits. The rectangular plates can come from a piece of scrap pipe, cut open and beaten flat.

[nimrod77]

Just wondering on the top end cap for the size of the vent hole, is 1/4" big enough?
Cheers

[jbrew9999]

You don't need a cap at all. But if you want one anyway, the hole is just there as a safety precaution so I guess 1/4" would be fine.

[Guest]

My advice (i.e. Alex's advice):

Plate: How will you know how *deep* to cut the slit for the plate? Depth matters so as to not obstruct vapor path! Do the math or email me for a template to help understand. Angle of plate isn't important as long as takeoff tube is submerged by condensate. Top plate and bottom plate should overlap by at least 1/4". Next, the vertical spacing between the bottom of the top plate...and the top of the bottom plate...should be *at least* 1/4". Top plate should be 1/16th (or more) smaller diameter than the coil.

Vent: NO cap at all. Top must be open. Condenser should stop all vapors. Wrap coil with copper packing material, plus, stuff inside coil with same. No vapors should escape.

Thermometer placement: 1/3rd of the way down the packing - just as the picture & instructions of the Mini-Still indicate. This will give you time to adjust to temp changes in column (ie. the content temp and therefore timing of cuts). If thermometer is placed higher and temp rises, by then tails will be in distillate - too late! You gain nothing by having it above packing. Alex made many tests to confirm this.

Flux: use water soluble, then hot water will remove it. Pre-clean column pipe and plates before soldering, then all to remove is the flux with a hot bath, then water test-run.

Just my $0.02, but info from the designer himself. Do as you wish. Mini-Still is great.

Eth&All

[OldStormy]

Hi Guys,
Thanks for the info. jbrew, I had already perceived the problem of the thermometer in the way of condensate - thanks for your response. Eth&All, thanks for the detailed response, very appreciated. I understand the placement of the thermometer a little better now as well as the top plate size.
Cheers,
OldStormy

[jbrew9999]

Alex is talking about soldering the top plate to the condenser. That is why it has to be smaller than the diameter of the coil. You could also just cut a slit for the top plate and install it just like the bottom plate. That way you wouldn't have to worry about what orientation your coil is in in the column. (the weight of your cooling hoses might want to spin the condenser into a certain position. That must be why Alex has that cut-out in the top of the mini-still for the coil tubes to sit in. Either method will work. His restricts the direction your cooling hoses come off the column but makes the lower plate easier to clean. Mine method allows your condeser to spin freely in the head and you don't have to cut any circular plates.

If you do solder the upper plate to the coil, make sure you position the coil so that any condensate that forms on it will hit the plate otherwise condensate from the coil on the 'high-side' of the plate might miss the plate completely and drip right back down the column.

[Guest]

>You could also just cut a slit for the top plate and install it just like the bottom plate. That way you wouldn't have to worry about what orientation your coil is in in the column. (the weight of your cooling hoses might want to spin the condenser into a certain position. That must be why Alex has that cut-out in the top of the mini-still for the coil tubes to sit in. Either method will work.

Orientation is important when soldering on top plate to coil, as described (it's job is to direct condensate to the lower plate). But weight of cooling hose.....I can't imagine that! The weight is minimal with 1/4" I.D. tubing and the amount of water in the hose is trivial (it barely flows out!) so no issue with pulling. If 1/4" copper tubing is wound as double helix coil onto a 1/2" pipe for a mandrel, then it will barely fit inside the 1.5" column (no slop). No way it will turn inside column once hoses are lined out to water supply. There's nothing tugging at it to make it move. This would be an issue if coil is substantially smaller than column; hmmmm - no it wouldn't either! It should be wrapped in copper gauze (e.g. coil in 2" column) there's just no pull on the coil at all from hoses. Cut-outs only put coil lower in the column if desired (careful of vertical spacing of plates!) because the intake/outflow tubing part of the coil sit on top of the column. Cut outs make it sit down flush (but not necessary).

>His restricts the direction your cooling hoses come off the column but makes the lower plate easier to clean. Mine method allows your condeser to spin freely in the head and you don't have to cut any circular plates.

I just can't see the [restricts] problem you describe and I have fed water from left and right and behind. Again, clear vinyl tubing is teeny amount of weight. Not sure of what spinning is all about. Water can be fed from any direction.

If you cut another slot for soldering in upper plate (instead of attaching to coil), do the math good!!!! Hope you don't get it in too deep, nor too close to lower plate. But yes, it does work just as good. Also, be sure to bend down center notch in lower plate before soldering in the upper plate!!!!!!!

>If you do solder the upper plate to the coil, make sure you position the coil so that any condensate that forms on it will hit the plate otherwise condensate from the coil on the 'high-side' of the plate might miss the plate completely and drip right back down the column.

Maybe, but there's a whole lot of dripping going right back down the column anyway - reflux! Condensate follows the circular coil right down to the plate.

Not making a troublesome disagreement, but what you describe doesn't sound like MiniStill I know (like in the picture). Just my advice from actually building/using the MiniStill. Nice discussion! - Eth&All

[Grayson_Stewart]

Orientation is important when soldering on top plate to coil, as described (it's job is to direct condensate to the lower plate). But weight of cooling hose.....I can't imagine that! The weight is minimal with 1/4" I.D. tubing and the amount of water in the hose is trivial (it barely flows out!) so no issue with pulling.

Huh? Faster water flow weighs more than sedentary water?

If 1/4" copper tubing is wound as double helix coil onto a 1/2" pipe for a mandrel, then it will barely fit inside the 1.5" column (no slop). No way it will turn inside column once hoses are lined out to water supply. There's nothing tugging at it to make it move.

You take a filled 3/4" garden hose and attach it to the end of your 1/4" tubing and see if 6 feet or more of garden hose swaying in a catenary arch like a power line doesn't have to be adjusted, rotated, moved, and lined up and the garden hose then tied off to something throughout a run.

Cut-outs only put coil lower in the column if desired

Wouldn't it just be easier to cut off another inch or so to achieve whatever elevation change is required for the coil??

If you cut another slot for soldering in upper plate (instead of attaching to coil), do the math good!!!! Hope you don't get it in too deep, nor too close to lower plate.

What math? Just wrap a string around the column on a slant and trace out a cut line for the top plate....move down whatever depth you desire and repeat with the string for the bottom plate cut. And if Bokokob reads this, I claim copyrights to the string idea

Maybe, but there's a whole lot of dripping going right back down the column anyway - reflux!

Sure is, and if you don't have a upper plate attached to the column by soldering in place that leakage back down the column will prevent you from ever knowing the true total distilate output thereby affecting the reflux ratio you could calculate. Also, you would never be able to use the detuned column as an efficient pot still head or for stripping runs.

[Guest]

Stewart if you want to run a water hose to the top of your column, go right ahead. Yeah I'd say that would pull over the Eiffel tower. But 3/8" O.D. (1/4" I.D.) vinyl supply lines ain't gonna move anything on a Mini-Still no matter which way they're pointing or how full of water they are.

The other points you made...gee, ...I don't know what to say! But hey, that's what forums are for - to exchange ideas. Thanks for comments.

Mini-Still builders - good luck building & using, and hope you like it. It's a dandy little thing that kicks butt. Build it however you want!!

[jbrew9999]

Thanks for the support, Grayson.


Eth&All,
Please note that the stability (structural) of the column is not only affected by the weight of the cooling hoses but also the lenth of the column,and the sturdiness of the boiler top (lid or bowl).

[manu de hanoi]

advice : calculate the height of water your steam will have to go through, that will give you the pressure in your boiler-----> your joints ( flour paste for example) might not hold the pressure.

[scree]

3.1415 x 1" = length of one inner coil = 3.14"
3.1415 x 1.75" = length of one outer coil = 5.49"

For a 5" long coil there would be 5"/.25" individual coils, or 20 coils of each.

[20 x 3.14"] + [20 x 5.49"] = 172.6"

172.6" / 12" = 14.38 ft of tubing required.

This does not account for the run of tubing used to reach the inlet and exit water supply.

1" = 2.54 cm

I basically did the same exercise except I worked backwards instead.
I figured on using 20' of 1/4" tubing.
Diameter x pi for the outer coil + diameter x pi for the inside coil.
I figured 2 turns per inch rather than 4 to allow for 1/4" spacing. For a 5" coil, it would take 10 turns for each coil.
In this case if I wanted 10' of tubing, I would add 3.14" to 5.49" for a factor of 8.63".
10' or 120" divided by 8.63" would give the number of wraps.
120/8.63= 13 wraps with about 8" remaining for connections or 12 wraps with around 16" for connections.
12 wraps would make a 6" condenser.
In my case, with a 3" outer coil and 2" inner, for 20' of tubing, it took 17 wraps for each coil or just over 8".

I notched the top of the head to fit the tubes. With a spot of solder they don't rub and the condenser is kept centered.

I wanted a lid to keep out dust as well as protect the ceiling in the shed from hot air.( Speaking of hot air...) Anyways,
I used a flat piece of thin copper sheeting for the lid. I soldered a finger (dead finger?) to the bottom of the lid that sets in the middle of the condenser. The finger has a good 1/2" of clearance, so it is not a tight fit at all. The whole thing is very light and unobstructed so that with any rise in pressure, it will work as a relief valve.