Photos of Offset-Head style Stills
The Offset-Head still (sometimes refered to as the Nixon-Stone) is capable of producing 96% pure alcohol. The design is
available either at http://www.gin-vodka.com
Some of the photos here show the design modified in a number of ways ...
|JourneyMans Vapour Management Still Head
||As per Nixon & McCaws "The Compleat Distiller" at http://www.amphora-society.com|
Attached is a picture of my new Vapor-Management still head.
It sits on top of a copper-scrubber-packed column and a standard
coiled-copper reflux condenser goes on top. (2" tubing for column
and reflux condenser.)
The safety bypass is on the back of the head / not in this picture
- EXTREMELY IMPORTANT.
Here's the design criteria:
- position thermocouple as close to distillate valve as possible
The probe active area is at the tip. It's positioned about 1/8" away, and
centered on, the valve input.
- Use a cork gasket and flange assembly to insulate the head from any cooling
effects of the reflux condenser.
- Get the distillate valve input out of the constricted/high-speed area between
the head and reflux condenser to eliminate any venturi effects through the Leibig.
- Angle the distillate valve downward to eliminate pooling of any distillate that
may condense there. (There shouldn't be any because:)
- Attach the distillate valve directly to the head to keep the valve as hot as possible.
Mike explains a bit more about how the Vapour Management head works ...
If you feed vapour to the middle point of a horizontal tube, then it will split into two streams.
If the cross-sectional area of one arm of the tube is A and the other is B, then the vapour will divide in that ratio, A/B.
You can control that cross-sectional area by means of gate valves, and this is useful for some applications.
If you feed vapour into the middle point of a vertical tube, density now becomes a factor and this can be used to control the behaviour of a distilling column depending on the composition of the vapour inside.
First thing to note is that vapour rises in a distillation column not because if convection, as some think, but because it is pushed by vapour generated in the boiler. All vapour in a distillation column therefore rises at the same rate no matter what its density, and at a rate determined by the power pumped into the boiler.
When vapour meets the middle point of the vertical tube, some will be driven further up the column and some will enter the tube. In practise, this middle feed point is sealed off by a gate valve in a side arm during stabilisation of the column, and the vertical tube comprises the path up to the top condenser and the path down to the product condenser. It is a 'kinked' vertical tube fed with vapor at its middle point. When the gate valve is opened, vapour enters the side arm and, if it is less dense than air, will try to rise. If it is denser than air then it falls. It cannot rise in the side arm as that arm only goes down, but can fall as it points down to the product condenser and collecting vessel. The gate valve controls amount that can enter the side arm.
The relative densities of steam at 100C, air at room temperature, and ethanol vapor at 78C are 0.6/1.0/1.6
If the vapour in the column is ethanol, then it will fall down through the product arm, and if it is steam then it will continue up to the top condenser.
The changeover point, when the vapor in the column is the same density as air, if when the vapour comprises 45.5% ethanol and 54.5% steam. The volume of vapour falling down through the side arm therefore tails off and finally stops as the vapour mix in the column approaches and then reaches this point.
As this represents the onset of tails, the side arm being at the top of the column, a vapour management still automatically stops delivering product before it is contaminated with a significant amount of tails. It is also the reason why you cannot test the operation of such a still using steam alone. Subsequent collection of tails can be done by turning off the top condenser, blocking that path with a rag in the top vent, and fully opening the gate valve. A rag is recommended for blocking the top vent as a gate valve would present the possibility that both gate valves could be closed together, sealing the whole still.
I made the still from the Nixon-Stone design outlined in the great
Making pure corn whiskey
A professional guide for amateur and micro distillers
By Ian Smiley
I highly recommend this book - it has great descriptions, information
almost all information I needed to build the still
I made a few modifications to the design - the main one being the size
the copper pipe used to build the column/condenser. The book's design is
for 1 1/4" pipe, I used 2" copper pipe, which almost doubles the volume of
the column. Also, I am converting a 316 stainless steel drum for the
boiler, rather than using a hot water service as suggested. A few other
modifications have been made, outlined below.
The column is made from 2" Copper, and is 1200mm
long. I've put a BSP tube join (male and female) between the column and
head, which is made from brass, so I can easily remove the head. At the
bottom of the column, there is another male 2" brass BSP tube fitting,
goes into the female 2" stainless steel BSP socket welded to the top of
boiler - so I can remove the column as well. The brass threaded fittings
are known as a 2" Brass BSP Tube bush and come as
male or female fitting, which gets soldered onto the end of
The boiler is a 60L 316 Stainless drum, which Jan put me on to (thanks
Jan!!!!), and I've put 2 x 1380 watt elements in it.
The elements were very easy to put in. I made the holes using a 32mm
'chassis punch' which creates the hole by two 'jaws' pulling together
through the metal wall. The elements are 'replacement' elements for the
Still Spirits still. If you order them for this purpose, you will also need
to ensure that you also order the aluminium nuts and power leads.
Inside the boiler, you can see the hole above where the socket for column
attachment is welded, and the 70mm stainless steel rod across the hole to
keep the scrubbers in. The rod is 4mm wide s/s, and spot welded either side
of the inside of the lid over the hole.
Again this is made from 2" copper pipe. Above and
below the T, there is a 50mm section of tube. On the bottom section, a
Female BSP tube bush is soldered, and this screws on to the top of the
column. The top section has a 2" copper tube cap, with a 40mm
pipe, attached to a series of compression fittings and adapters, eventually
to hold the 3mm stainless steel probe of the digital thermometer, via the
3mm brass compression fitting.
Horizontally out of the T, there is a 40mm section of 2" pipe, going to
elbow, then a 370mm vertical section for the condenser to go in. At the
bottom of the elbow, another 40mm of 3/8" copper pipe is soldered
the horizontal pipe/elbow join (for strength). The top of this piece is
flush with the inside of the pipe/elbow join, and it is here the product
goes down through the needle valve, and eventually to the waiting
Inside the 50mm section of pipe below the T, with the BSP fitting that
screws onto the column, I have also made another modification - a angled
copper plate to direct the reflux flow down the center of the column - On
the photo you can also see the 'lip' I bent in the middle of it.
Note: In the broken down photos of the head and head and column,
horizontal section going from the T to the elbow in the head is quite a lot
longer than 40mm. This photo was taken before I shortened it, to decrease
the tipping effect of having a full condenser a long way from the
The condenser coil is made from 3/16" copper pipe, which was wound
to form the coils. I modified the condenser design so it is longer than the
design in the book, and also has a smaller internal coil at the top within
the main condenser coil, so any vapours reaching the top of the condenser in
theory get condensed rather than escaping. This removes the need for a
scrubber poked down the middle of the coil, as is often suggested with the
standard coil design. The intake pipe goes down 120mm inside the main coil,
then coils around itself back to the top to form this internal coil. This
then wraps around itself again, forming the main coil which extends all the
way down the condenser (360mm), and the returns through the middle of it
The hoses running to and from the condeser coil are 133mm clear PVC tube,
and connect to the condenser with a brass nipple-3/16" compression
fitting. The inlet attaches to the kitchen tap with a hose
The still stands 2.05 meters all up, bottom of drum to top of
condenser, but collapses down into pieces. The head can also attach directly
to the lid without the column, to use as a pot still for beer stripping.
I have 13mm Armaflex insulation on the column to insulate it. I thought I
may have to cut the insulation, but I managed to slip it over the male tube
fitting, so was able to keep it 100% whole!
I also made velcro straps which go around the column to hold the condenser
hoses to the column, keeping everything nice and neat.
It took 18 small stainless steel scrubbers to fill the column.
Running time, purity
Heat up: The boiler took 1:00 hour to heat a 25L
13.1% wash to boiling.
Reflux: Total reflux was 80mL/minute
Purity: 96% at 15 mL/minute (first run - will test
Condenser: The bottom 100mm of the condenser out coils
were used (covered in condensate); The bottom 3 coils of the inner coil
(inside top 100mm) were also used. Flow rate was 600mL/minute.
Efficiency: Of the first run, 93% of alcohol from the wash
All the brass has been treated to get rid of surface lead, as detailed
After the first treatment, it seemed to work well, each step getting
fittings cleaner and more
shiny, BUT.... After taking the fittings out, they went from shiny to dull
with the typical green/blue tarnishing you see on old brass fittings -
took about 3 - 5 minutes. After a bit of experimenting, I found that if I
put them back in the peroxide/vinegar solution, they lost the tarnishing,
and got shiny again. This was the exact same solution - not a re-mix. I
also found that leaving them in there for a longer time (around 12 minutes
total) got them shinier, and also they fizzed in the solution (which
happen the first time). When I took them out, I quickly dried them with
tissue paper toweling, and then with a cotton cloth. After this, they
remained nice and shiny, except for the absolute bottom of the thread
groves, in which I assume a small amount of solution remained. The
went semi light blue colour (about half the intensity of the picture on
mybrewery web site).
|Rob van Leuven's Offset-Head Column
||This is how I fixed the problem of
securing the tower to the top of my urn. The white disc is a painted disc of
MDF clamped down onto the s/s urn top using 4 x 6mm threaded brass rods.
These are fixed to the inset brass strip that secures the curved wooden slats
forming the urn insulation. To seal the urn top I use a length of thin silicon
rubber tubing, slit down its length and threaded round the disc's edge. The
white cord fastened by the needle valve is just a bit of additional 'belt &
Urn is a converted 40 liter SS tea urn. The urn is double skinned and is
insulated between the two walls of SS. There were no elements in the tank
when I obtained it. The two elements are 2400watt and 1500watt for fast boil
Power supply is three 240volt individually switched outlets. One outlet is a
triac controlled. I boil up on full power and then switch off the 2400w and
switch the 1500w to the triac plug and distill under triac control.
The tower is 1200mm x 50mm diam measured from the base of tower to center of
50mm tee. The condenser housing is 40mm diam. The cooling coil is 600mm long
x 8mm diam (about meters of tube to construct the coil).
I think I have about 12ss scrubbers from the base to the top of the reflux
return pipe (12mm diam)
Insulation is 150mm black compressible plumbers foam.
The insulation is held in place by a cotton sleeve fastened with Velcro.
|My Still !
Size : 30 L |
Heat Input : 1800 W
Column : 1.1 m x 1.5 inch diameter
Packing : 12 pot scourers
Condensor : 13 ft of 3/16 copper
Purity : 95%+ at 40 mL/min
Design : Nixon-Stone
Cost : NZ$300 (US$120)
|Tom "the StillPastor"s Still
email : THART@FIRSTPRESABQ.ORG
The pot is a 15.5 gallon beer keg with two 1" threaded inlets welded near
the bottom. This kettle is heated with two water heater elements- each a
1500 W 110 volt element. This may change, I will have to see as time goes
by. Suggestions are welcomed.|
The column is 3" in diameter and stands 1.25 meters tall with an internal
cooling loop at about 1 meters The column is removable and has a
perferated plate at the bottom. The column is also constructed in two
parts, being divided just below the internal coil near the top. The lower
meter of the column is insulated with boiler pipe insulation, and the column
packed with S/S scrubbies up to the internal coil.
The still actually has two heads. The first is the one I originally
constructed, which is a simple pass through, jacketed condenser made of
copper. This condenser is actually design so that water flows both around
and through the consensing tube. It works great. The second is a new
fractionating head also made of copper roughly based on a Nixon/Stone
design. The actual design for this head is here. I
included both heads on this still because I could and I enjoy having
options, besides what else would I do with the old one?
The various valves you see in the pictures are all ball valves to control
the flow of the chilling water, vapor and distillate. I am able to run the
still in a variety of configurations with this set-up and as I said earlier
I enjoy having options to play with.
The top of the column is open to accept the probe for my digital
In addition to my new electric kettle, I also have my original 10 gallon pot
that is double walled and heated with hot water or steam depending on how I
wish to run it. More options.
|Ned Steamgoon's Still
The stillhead is based on Tom Hart's design from the Yahoo Distillers
group (see above) - it is 0.5 metres from the reflux needle valve to the water outlet
tube at the top. The vapour tube from the column and the main tube of the
condenser are 40mm, the outer jacket is 50mm. The inner core is 25mm and its
outlet tube is 12.5mm. Water enters the outer jacket at the top for
counterflow - the outlets of the inner and outer are each controlled by
their own ball valve. With the ball valves half open it does not get warm
any further than about 150mm up from the vapour inlet so it probably needs
be only half as high.|
The main column is 1200mm x 50mm packed with 13 jumbo SS scrubbers. The urn
is rated at 2400 watts. It produces over 1.5 litres per hour at 93%.