3" Graham oops/Dimroth coil for VM reflux column

[tiramisu]

How much 3/8' copper tube or sst should I buy to make my coil 3" coil?

Looks like common lengths are 10, 20 and 50 feet.
Will the 20 footer be adequate?

Trying to search this one is painful.
I'm sure plenty of you have been here before me.

Thanks
T

[Yummyrum]

I’m guessing you’re talking about the reflux condenser . In which case it is called a Dimroth not a Graham

A Graham condenser usually has the vapour run through the coil and is surrounded in water .

Anyway , just a bit of napkin math . A single coil of 3/8 that will just fit inside a 3” would be just under 7” long .

So say it was going to be about 12” long , and each coil was evenly spaced by 3/8” , then you would need about 15 turns .A little over 8’ .

[tiramisu]

@Yummyrum... dimroth it is... Inner coil and outer coil.
Thanks for getting me thinking about it right.

c = pi(r)^2 = 7"

Outer Coil (3" diameter)

12" = coils / (3/8 + 1/4 (gap ) )
12 = coils / .625
19.2 = coils

length = 19.2 coils * 7" = 134.4

Inner coil (1 3/4" diameter )

3 (outer) - 6/8 (tubing) - 1/4 (gap) - 1/4 (gap)
24/8 - 6/8 - 2/8 - 2/8 = 14/8 = 1 3/4

c = pi* (.875)^2 = 2.4

length = 19.2 * 2.4 = 46

1.75 - 6/8 = 1

probably want to run a straight length right up the middle

1 foot

So theoretically 20 feet of 3/8 is fine assuming you don't kink the copper trying to twist the inner coil.....

[tiramisu]

If is assume a 1/4" gap from the outside.
I need to wrap the outside coil around a 1 3/4 pipe and the inner around a 1" pipe.

[OtisT]

If Electric, what is your max input power level?

Are you using city water? (Consistent temp and pressure throughout the run.)

I can knock down (barely) 5500W with only 11’ of 1/4” copper tubing coiled. (City water, 3.5 lpm flow rate). You can get a lot more flow through the 3/8, so if you have a consistent flow of cool water and can run at or above 1 gallon per minute, you should be able to get by with 10’ or less of 3/8” copper.

I’m getting close to testing some 3/8” coils in my new condenser, so I should have some stats on 3/8” coils to share in about a month.

Otis

[Tropic]

c = pi(r)^2 = 7"

Area = pi X radius squared

Did you mean
Circumference = pi X diameter

[tiramisu]

If Electric, what is your max input power level?

Are you using city water? (Consistent temp and pressure throughout the run.)

I can knock down (barely) 5500W with only 11’ of 1/4” copper tubing coiled. (City water, 3.5 lpm flow rate). You can get a lot more flow through the 3/8, so if you have a consistent flow of cool water and can run at or above 1 gallon per minute, you should be able to get by with 10’ or less of 3/8” copper.

I’m getting close to testing some 3/8” coils in my new condenser, so I should have some stats on 3/8” coils to share in about a month.

Otis

I read your old post on twisting 1/4 and am a bit concerned about kinking the 3/8"

I also have a 240w 5500 element on the shelf for my beer keg and will be using city water.

It continues to surprise/concern me how much water is required for cooling.
I suppose I shouldn't be surprised that cooling down 5kw of power takes a metric boatload of water.

My ceiling height is 102" and my planned still height is 97"
with the steam head being about 58"

So the extra 2" would definitely be nice to have.

image.png (3.96 KiB) Viewed 1032 times

How long does a stripping run take you?
How much power can you put into your spirits runs for neutral? for pot?

This guy has been getting lots of minor criticism for his still ( I think it is pretty ) but his cooling
seems very effective - running a small cube freezer overnight (I am tempted).

[attachment=0]image.png[/attachment]

[The Baker]

If you run a straight bit up the middle you may well have a Davies condenser.

I did that to my liebig condenser to make a Davies condenser (water outside and inside, vapour in the middle)
because the condenser I was given had too big a tube in the middle, it was originally used for a different purpose.
Haven't tried it yet.

Geoff