still design idea

[tomgndallas]

I was sitting watching my t500 run, and since it can be a little boring, i decided to make this visio file of an idea i had...



masters, please prepare to throw your darts!

3 foot, 3 inch copper tower, with a 6 plate tree. top condensor is 6 inches, will most likely be a double coil. product passes through a graham on the way out. first 12 inches is open to allow for copper packing or maybe some rachig rings? I dunno yet. I think the length may be a little short, maybe a 4 footer would be better.

[Prairiepiss]

Have you been researching the flute builds? If not you should. What are you going to use as a boiler to feed that beast? Shotgun on top would probably better suit it.

[tomgndallas]

some here and there, the thing is there is so much information and experimentation, it is difficult to wade through it all.

if I ever build this thing, i would feed it with either a beer keg or get a hillbillstill 8 gallon and put a heating element in it.

I am not sold on the 3 inch, it is expensive, so 2 inch may be a better way to go, something like 40 inches total length, i could look into the shotgun, and then do a 4 inch spacing on the plates, with either 1/8 or 1/16th holes. would have to research that more.

anywho, was just doing a mental excercise to test out the concept.

[mash rookie]

some here and there, the thing is there is so much information and experimentation, it is difficult to wade through it all.

if I ever build this thing, i would feed it with either a beer keg or get a hillbillstill 8 gallon and put a heating element in it.

I am not sold on the 3 inch, it is expensive, so 2 inch may be a better way to go, something like 40 inches total length, i could look into the shotgun, and then do a 4 inch spacing on the plates, with either 1/8 or 1/16th holes. would have to research that more.

anywho, was just doing a mental excercise to test out the concept.

Nice drawing of a typical plated flute Tom. Plans and details are already out there for you. 1/16 is better than 1/8". Coil condenser will work if it is large enough and you can push enough water through it. Surface area for vapor contact is critical at the speeds that flutes run at. That is the main reason to build a shotgun.

Dont bother trying to build a two inch flute. That has been tried with little success.

MR

[tomgndallas]

well i guess if i wanted to go flutey i better go to 3 inches. I was planning on having Mike at Hillbilly take my still spirits column, cut it and weld up one of his connector flanges. i think he has something that would step up to 3 inch, then i could make plates if i wanted. i wanted to mate this to my T500 boiler, just not sure it would be a great idea to put all that weight on it.

i had posted the following on another thread...better suited here.

off topic but related...

we are talking boiler size to column ratio, is there a rough figure for that? or are you simply just calculating the total volume of the twins and figuring boiler size? 2 big ass 8 inch monsters would definitely require a big boiler.

Also previous reading told me that column lenth is 20 x diameter. So for a 2 inch reflux you would need 40 inch column. this twinstill at 8 inch would need the 8 foot and another 5 1/3rd feet, right?

in my case, if i went to 3 inches on the column, i would need a 5 foot length? this does not seem right to me.

any rules of thumb for leibig or graham size and length?

tried searching the google hd, not that successful so far on these ratios other than length to diameter

[tomgndallas]

more thoughts on design, been reading the last two days...

so if i stuck to the 2 inch, i could do 40 inches length, have a t step it to 3/8, run it through a ball valve then reduce to 1/4 inch through the condenser to the output. i will try to wind an 8 inch double coil for the top, and do a 1.5 inch graham condensor at 16 inches total length.

comments? basically a vm still column sitting on the glorified coffee pot t500 boiler, which i can easily load almost 30 liters into.

[tomgndallas]

this would be a much simpler design to start out with. would be going from a t500 CM type to a home built VM type with T500 boiler...



I would think I would be able to get a better spirit run, better seperation, good purity and it would run maybe a little faster??


nobody loves me everybody hates me going to the garden to eat some worms, SOME WORMS!

hehe

[maheel]

are you looking for neutral or flavoured spirit ?

a bok build is about as simple as they get if your looking for neutral

[tomgndallas]

I generally make vodka, so yes neutrals. looking for better performance overall.

[tomgndallas]

any thoughts on size ratios masters?

I have yet to really receive some clear cut guidance here, if there is any...

to reiterate my questions

ratio of column diameter to length of column roughly 1:2?
boiler size to column volume - about 1:1? For instance a 40 inch x 2 column would be around 112 cubic inches, translates to 1.8 liters volume distillate, so 20 liter boiler.
- my thoughts here is that you need to be able to at least keep up with the column volumn so that you can get full reflux of distillate?
boiler size, column volume, heater wattage guideline...I have either an 1800 or 2 KW running my still, research yielded mixed results.
- research on HD has shown that this wattage should be fine, but is there a rule of thumb?
insulating the column should account for losses due to conduction and the increased column length. The T500 stock column is only 23.5 inches in length, the one I will build will be around 40 inches, so I will be coming close to double the length.

ratio of size of leibig or graham to column size?

- for instance if I have a 40 inch column, would a 18 inch graham fairly tightly wound with 1/4 inch, with a 1.5 inch cooling jacket be sufficient? I think definitely so.

ratio of reflux condenser size to total column volume?

- I have seen folks post they are using 8 inch double wound cooling coils, but have also read caution on over cooling. I am thinking of stepping mine down to 6 inches, double wound.
- thoughts?


I would like for this thread to one day help out the novices, hence the reason I am trying to consolidate as much engineering information into one spot, and get some confidence on my design ideas.

Cheers and good morning gents!

Tom G

[rad14701]

The Height:Diameter ratios are only relevant for 2" or under...

As for the boiler size to column size, there are a few possible variables... For a plated column you need to consider the amount of liquid on top of each plate more than vapor in the free space... You will want a fair amount more alcohol in in the boiler than on the plates, otherwise you will end up playing still jockey throughout the run because the boiler temperature will rise too quickly...

Is there a hard and true figure for that...??? Probably not... You need to run by gut instinct and the seat of your pants... Personally, at the start of a run I'd want at least ten times as much alcohol in the boiler as on the plates...

Example using purely random volumes... If a plated column holds a total of 500ml of liquid on top of the plates I'd want about 5 liters of alcohol in the boiler at the start of my run... So for a 10% wash I'd need a 50 liter initial boiler charge...

Now, for a reflux column filled with structured packing I'd be comfortable cutting that volume in half, to 25 liters, because the structured packing would hold less liquid... Call it BevNap science or years of practical common sense, whichever you like, but I doubt you'd go wrong with those numbers... Of course someone else might toss out different numbers... You might be able to go lower, but I wouldn't consider going much lower myself... So, for me at least, it's more about alcohol/fluid retention volume than physical volume with regard to a ratio...

I wouldn't start crunching a bunch of physics numbers about to come up with an answer because I'm not into putting that much effort into coming up with an exact answer that probably wouldn't be far from my estimation... To do so would require additional variables like boiler head space and a whole slew of others that push more towards theoretical than practical...

[tomgndallas]

that was a great reply Rad, I think I feel much more comfortable with my design....

one last question on the VM...it needs a vent port in the top? I guess this makes sense so you don't overpressurize the column when boiling. I was thinking you could just leave the take off valve at the split cracked to relieve any excess pressure.

I will try to read up more on this, saw it in a thread last night, just wanted to follow up.

Tom G