Steam heating for a copper pot still?

[phenol 90]

Hi folks,

New to sign up to the group although I've been reading through plenty of the posts and resources. I just posted a welcome note, but here's a bit more about where I am at.

Oh yeah, pleased to meet you!

I've got a question for anyone out there who may be able to answer it. I've posted this in the yahoo distillers group too just in case anyone comes across it again.

I'm weighing up all the different heating options and was curious as to whether anyone has ever used or built a steam heating system operating through an internal coil in their still?


I'm designing a 20 gallon copper pot still modeled on a traditional single malt whiskey still. I have a 60 gallon copper tank from a water heater that is going to get cut up, stripped of all soldering and lead and rebuilt to size and specs.

The issue of burning the wash with the heating source, whether it be direct fired or internal is what has got me losing sleep at the moment. A lot of people out there have discussed that immersion elements and direct fired heating can or will burn all-grain worts (wash).


I'm a long time all grain home brewer with a decent set up in operation and will be continuing down the malted barley path. Because of this, the heat and burn factor seems a major design issue I need to consider.


I'm aware of the heat baths that some people are using but want to keep the flames away from the still which will be located indoors. The rough plan that I currently have is that I could direct fire a steam heating unit (water filled keg with pressure relief valve) outside the still location that pipes into the still, coils around inside, and then recycles back out to the unit. The pipes running from the heating unit would be insulated to retain heat and travel distance would be kept to a minimum.


So again, has anyone seen, used, designed and/or built anything along these lines before?


Any comments or advice would be much appreciated.


Hope this makes sense.

Thanks in advance,

Phenol 90.

[schnell]

your water heater tank probably doesn't have any lead solder on it. (unless its really really old)

i doubt many folks have messed with steam coils. there's some challenges with pressure and condensate return. they are usually used on much larger equipment (commercial).

direct steam injection is an alternative that takes alot less engineering, but it'll tend to be adding water to the boiler as injected steam. this has been done in the past by smaller operators.

if you don't distill on the grains I think you shouldn't have to many problems with a direct fired still. other folks may not agree though.

[Slow & Steady]

I have seen steam heated stills in Scotland. All that I have seen so far were using internal heat transfer units. All separated the wash from the grain previous to fermentation. I have fermented on the grain then separated previous to distillation and I have distilled on the grain. I don't like distilling on the grain as the post distillation clean up and the nuisance of a grain laden hot slop make disposal a bit problematic. A boiled out distillers beer will disappear into the ground when poured out but if you pour a grain laden hot slop on the ground it is going to be there for a good long time. If you apply heat to fast to a grain laden wash you get a very nasty puking wash that is no fun to clean up after, although a grain cleared wash can still puke it isn't such a pain in the arse to clean up after.

S&S

[Hillbilly Rebel]

If you are in the area, visit Woodford Reserves Distillery outside of Frankfort, KY. That is what they use to heat their commercial size pot stills.

[Tater]

Mash was stirred till ready to cap and run to keep from sticking way it was done in small scale stills around here. Ones who didnt do that made steam boilers and steam heated it . Like other post said this added some water condensed back into still .Way they worked around that was have bigger still and thumper .A home made boiler outta a 55 gallon barrel would drive a 100 gallon still and 75 gallon thumper.and 35 to 55 gallon puke barrel usally they were wood .So smaller scale for hobby shouldn't be to hard to build. Been planning on one day doing that very thing myself.Was the preferred way by several of old shinner ive know .

[MashMan]

Mash was stirred till ready to cap and run to keep from sticking way it was done in small scale stills around here. Ones who didnt do that made steam boilers and steam heated it . Like other post said this added some water condensed back into still .Way they worked around that was have bigger still and thumper .A home made boiler outta a 55 gallon barrel would drive a 100 gallon still and 75 gallon thumper.and 35 to 55 gallon puke barrel usally they were wood .So smaller scale for hobby shouldn't be to hard to build. Been planning on one day doing that very thing myself.Was the preferred way by several of old shinner ive know .

Hiya Tater,
I have often wondered about using direct steam to fire a boiler myself it would be awesome for any wash with solids, my mash tun is heated by steam and I use it to heat and cook everything, it would be so easy to use my setup to direct feed steam into a boiler.

so lets say you were doing a steam injected strippin run and as the run progressed the wash in the boiler %alc decreased and the %water from steam increased, which should be less volume gain than the volume loss from spirit collected. is there going to be an increased volume collected at lower %alc because of the dilution of the wash? having trouble getting my head around this, on the other hand I cant help think that not much would change

Anyone have an opinion i would love to hear it.

cheers
mashman

[Tater]

Not sure what ya mean by a stripping run with this kind of setup. If first run aint up to proof it goes into thumper next run .

[MashMan]

oh man I never explain myself properly, I'm talking about a boiler only no thumper.

[Tater]

Id think there be more water added to wash from steam as alcohol percents drops.

[MashMan]

ok I get that. but what do you think about the %alc collected over the whole run compared to external heat source?

[Hawke]

I'm going to say the overall ABV of the distillate is going to be lower by maybe 10%.
Instead of collecting at 40%, you would get 36% average.
You could probably cut this gap a little by having a full head of steam before diverting it to the pot.

[myles]

I think there are three basic steam options although I may be wrong.

1. Pass the steam through a coil in the boiler.

2. Put the steam in a sealed pressurised jacket around the boiler.

3. Sit the boiler in a water bath with most of the surface exposed to steam.

I think the best is option 2. It gives you an increased temperature gradient into the boiler - I have NOT tried it. I did try option 3. It is the easiest and I have no doubt it works fine if you can have your still outside. I tried it indoors and the escaping steam turned my still room into a sauna.

I have kept my option 3 boiler, it but switched the liquid to propylene glycol instead of water. First run should be today.

Option 1 seems fine for remote boiler opperation and is probably what I would use if I was going to heat with solid fuel like wood.

[MashMan]

Ok myles keep us posted on the outcome.

I'm going to do some minor plumbing mods in the next week or so and do some comparative strippin runs on molasses wash, external propane heat vs option 4 direct steam injection into the wash and see what the overall abv difference is. I'm going to use two 1" reducers screwed into the electric element sockets of my boiler with 300mm of 1/2" tube with 2mm holes for steam to enter boiler. This will be conected to my steam generator.
will do as tater suggested and have a full head of steam before it enters the boiler.

will give an update as it happens.

[phenol 90]

Right on!

Some interesting posts so far. It's good to see some discussion centered on the various options of steam heating as I've found it difficult to find much on this.

Here's a link to a similar post made on the yahoo new distillers forum:

http://groups.yahoo.com/group/new_disti ... sage/36552" onclick="window.open(this.href);return false;" rel="nofollow

I'm now thinking I'll go electric with an immersion ellement in terms of heating. Reason being, it seems that there is no need to worry about burning an all grain wash with an internal ellement providing one is not distilling on the actual grains and filters correctly.

This was why I was considering an internal steam heating coil as an option as I don't want to direct fire the still due to inside set up and safety concerns. Also, it would appear that steam heating with an internal coil is not a very energy efficient method. At least that is what I have learn't thus far.

Wonder what the options are for efficiently heating 50 -70 litres (13 - 19 gallons) with an electric immersion ellement. Could I avoid the cost of having a three phase power outlet installed. Any ideas? Perhaps I need to start a new thread as this is different to the current topic of steam heating.

Anyhow, great to hear about the different options people are using with steam heating...

[myles]

It is very easy to be seduced by the steam / double boiler / indirect heating option. I know because I was

I am persisting with it because I went to a lot of trouble to make an insulated double boiler and I hate giving in. The reality is that I very rarely will actually NEED it. Sure I ferment mostly fruit, and am partial to grappa style clear brandies, but I generally take the time to settle and rack off. Its not often that I actually distill thick washes. I keep meaning to but it is extra work.

Do you really NEED steam? I would love to go down the route of a wood fired steam generater feeding a 30psi jacketed boiler but am not sure I could justify the need for it.

I keep redesigning my sauna with the still hidden in a false wall, but am dubious about if I would ever actually build it, Nice idea though.

[Tater]

even on a hobby still id go large on pipe from boiler to still and still to thumper .if i was gonna use a beer keg as boiler id go at least two in tubing. and make sure theres some kind of safety blow off pointed away from ya

[Hutch-]

I ferment mostly fruit, and am partial to grappa style clear brandies, but I generally take the time to settle and rack off. Its not often that I actually distill thick washes. I keep meaning to but it is extra work.

Do you really NEED steam? I would love to go down the route of a wood fired steam generater feeding a 30psi jacketed boiler but am not sure I could justify the need for it.

This situation fits mine exactly. My biggest concern is how to build a jacket around the boiler to retain the steam.

[Tater]

As in my fruit recipe posted I remove seed and skins and ferment only pulp on peaches plums ect..I run this wash with a lp fired burner .I use lots of copper pieces in still and watch my heat. And so far haven't had a problem with scorching. Only time I have scorched fruit when stilling was some pear I was making and had chunks in it .Went to grinding apples and pears after freezing and haven't had a problem with them since then..

[azeo]

Electric is clean and easy, but costly if doing alot. I run two elements for a still that can take up to 60L, A large surface area jam preserver 1500W element, for the simmering, and additional 2kW jug/kettle one for bringing up to the boil. Only the occaisonal problem with the 2kW, and sometimes have knocked it back a bit with a power controller for muddy or starchy washes.

I'm also keen on the steam idea to help reduce the burning affect of direct heat from a wood fire, although with care, fires are ok, who's cooked dinner out in the woods? It's the way things used to be done.

In effect one is making two stills, and the flake stand then becomes the wash boiler... with this in mind a whole host of ideas can spring forth, from simple, to boiler making and heat exchanger masterpieces, with anything in between, It's also worth looking at steam engine design as once you only have to "roast" water, all manner of schemes to extract maximum heat from the source can be cooked up. The most important issue is it would be best to have the system non-pressurised, the steam path as short as possible, and the condensed water from heating the wash boiler returning to the steam boiler as warm as possible.

All possible, in fact the steam path could be so short as to have the wash boiler sitting in the steam boiler exposed to the steam, but not in the water, as in previous descriptions, pot in pot. All you need is a flange on the wash pot, a matching lip or flange on the boiler pot, and a side fed, open top reflux column returning condensed steam to the bottom of the boiler pot so as to have a water lock.

For the excess steam from the boiler after heating wash, and the steam rising from a connecting tube, think reflux column operating at 100% to return water back to the boiler and it'll be a closed cycle, non pressurised (unless you want to put a weighed valve, or spring safety valve on top of the steam boiler reflux column to increase pressure - not really worth the risk though - a boiler explosion will kill, easily). In fact, if the system was really efficient, or the wash pot could absorb enough energy from the steam to boil properly, and the right amount of steam was being produced, *no* excess steam would result, the wash pot would be condensing it all.

For a longer path, they could be separated, even with a dividing wall, and looking at pictures of distilleries that often seems to be what one sees between the wash boiler and the condensor.

For a quick test, it could be worth making a flake stand to put wash in, with a half height coil, sealed lid , run water or glycol or similar in the original still, and the steam directly to the flake stand, mount the column and condensor off the original still onto the flake stand lid, put wash or water in the flake stand, cover everything in insulation, and let her rip! Make sure your boiler doesn't run dry as at this stage, unless your "flake stand" wash boiler is high enough to return the condensate via a vented return pipe to the boiler. I should draw up some good sketches, like they say, a picture....

A steam heated mash tun sounds like the perfect candidate already.....

[MashMan]

[quot="azeo"] A steam heated mash tun sounds like the perfect candidate already.....[/quote]

Hi azeo, I have been using a steam heated 50l keg mash tun for a long time. The hole in the top was sized to allow my 25l boiler to fit in snugly, the 25l boiler has a swaged line around it about 6in from the top which it sits and seals on, there is enough space between the bottom of the boiler and the mash tun to allow about 10l of condensate to collect before it touches the boiler. I use this setup for my fruit washes, peaches, apples, apricots etc. it works unreal. the steam generator can be gas or electric heated, using electric with pints controller I can do a fast strippin run with almost zero steam leakage, nearly 100% condensed, i think the heat transfer is fairly efficient with the large surface area of the boiler.
unfortunately 25l is a bit small for low abv fruit washes 50l would be much better, which is why (as per my prior posts) later this week i am going to run a couple of comparitive 50l molasses runs, one externaly propane heated and the other direct steam into the wash just to see what the abv difference is as well as wash volume gained or lossed.

If anyone can give me the heads up on posting pics (i think i worked it out?) i'll see what I can do.

cheers.

[Hillbilly Rebel]

In a way, anyone with a thumper is doing a steam heat. After all, it is the vapor from the still that is heating the mash/low wines in the thumper. A simple experimentation would be to add a second thumper and use your still as the boiler with water in it and your raw mash in the first thumper.

[azeo]

HI Mashman, sounds like a great setup, be good to see some pics - their could weel be a cunning way to use your existing setup to do larger washes. It's much easier to upload pics now, using the the "upload attachment" tab below the erply window. Still getting familiar with it, but it seems to have worked for me ok .I put my pictures for posting in an easily found directory and a program like "Irfan View" can be used to shrink the file to a reasonable size and convert any bmp to jpg format. Windows programs can do the same thing but I prefer tried and true that works for me, many other ways though.

Hi HillyBilly, nice idea and easy to test, I wonder if it would work well for a spirit run, or add yet another thumper, I think Tater may have descibed this earlier... If one turns everything around and stacks the thumpers on top of each other, you get a steam driven column plate still...

Cheers folks

[muckanic]

I'm now thinking I'll go electric with an immersion ellement in terms of heating. Reason being, it seems that there is no need to worry about burning an all grain wash with an internal ellement providing one is not distilling on the actual grains and filters correctly.

This was why I was considering an internal steam heating coil as an option as I don't want to direct fire the still due to inside set up and safety concerns. Also, it would appear that steam heating with an internal coil is not a very energy efficient method.

Who said the heat exchanger has to carry steam? Boiling water would support alcohol distillation nearly as well.

Wonder what the options are for efficiently heating 50 -70 litres (13 - 19 gallons) with an electric immersion ellement. Could I avoid the cost of having a three phase power outlet installed. Any ideas?

I can just boil 50L of beer, with the lid partially on, with a 2400W element (ie, pulling 10 amps straight out of the wall). What most brewers do when they want more oomph is to run dual elements, making sure they are plugged into different circuits if necessary to avoid blowing the fuses. My place has two 15A power fuses, and there is always the slightly dodgy option of tapping into the higher-rated stove or hot water service circuits.

However, we're talking distilling and not beer here. You probably don't need 2400W once the wash has been brought up to temperature. The main advantage of more electrical oomph is a shorter waiting time. Also, seeing you have a nice conductive copper boiler, why not sit it inside a double boiler and heat that with an immersion element? An immersed element is way more efficient than an external hotplate of the same wattage, because it doesn't lose heat to its surroundings.

As I have opined before, I reckon a quick n dirty way to go is to sit the inner boiler completely inside the outer boiler, place a lid on, and have a column sticking up through. This reduces steam and hence heat losses, and saves mucking around with attaching flanges, lips and the like to the two boilers.

[MashMan]

Hi azeo, pics as requested, these were taken when the steam conversion of the mash tun took place, quite a while ago now and since then
things have changed a lot ( does it ever stop) boiler, tun and copper line fully insulated, drains in mash tun as well as boilers, electric as well as gas, up off the floor etc etc.

This is the steam inlet ring that sits in the bottom of the mash tun.

Here it is slipped into the s/s compression fitting that is welded into the side of the keg.

This is the mock up with the 25l boiler in the mash tun, now a double boiler.

This is the steam generator outlet, tri clamp block off plate two 13mm holes one for the outlet with compression fitting, the other for the pressure relief valve.

These are the parts for my relief valve, simple and failsafe, tri clamp block of plate, copper tap washer with hole drilled through centre for screw, s/s spring from keg valve cut down, copper bucket for spring to sit in made from 1" tube, 2 1/2" screw to hold it all together,
if tri clamp plate warps when welding on compression fitting use thin cardboard gasket under copper valve for perfect seal.
used a pressure gauge to set valve at 100kpa, which is one 5th of what keg is rated at.
Once boiler is up to steam it takes 45min to boil an all grain brew, less than 30min for the 25l boiler.

will give an update by next weekend on the steam boiled 50l keg mollasses run.

cheers.

[phenol 90]

Great photos mashman, can't wait to see the follow up.

Who said the heat exchanger has to carry steam? Boiling water would support alcohol distillation nearly as well.

Fair point muckanic. I'm certainly not suggesting that steam is the only substance that could be transferred through the internal pipe (heat exchanger) to heat the wash, though. Nevertheless, it is the approach that the majority of distilleries in Scotland adopt for heating their wash and spirit. Given this, I was interested in whether anyone had attempted to replicate the process as I was unable to find any posts detailing such. Therefore the title of this thread.

As I have opined before, I reckon a quick n dirty way to go is to sit the inner boiler completely inside the outer boiler, place a lid on, and have a column sticking up through.

Interesting to see the variety of discussion rolling on about steam-heating and alternative ways of fashioning an approach to this. A double boiler makes sense, but I think in my case I'll be hard pressed to find a pot big enough to jacket my still in. It's going to be low and wide. Picture a very scaled down (70 litre) version of the traditional Scottish Whisky still, such as those displayed on the parent site. I could build something from scratch perhaps...

Anyway, I'm going with a low-density 2,400 watt screw-in electric immersion element inside the boiler, although.......all this talk about steam heating is getting me to think that way again, at least for the challenge. Maybe on another project later on down the track, don't want to get ahead of myself .

Cheers,

Phenol

[muckanic]

This is the steam inlet ring that sits in the bottom of the mash tun.

It's a bit hard to see how many holes you have in it but, as I have speculated before, that sort of thing could also function as a manifold for draining the mash tun when sparging beer. I take it you use a separate drainage system? Does the steam dilute the mash much (assuming you are mashing in at at least 40C)?

[HookLine]

Wonder what the options are for efficiently heating 50 -70 litres (13 - 19 gallons) with an electric immersion ellement. Could I avoid the cost of having a three phase power outlet installed. Any ideas?

...and there is always the slightly dodgy option of tapping into the higher-rated stove or hot water service circuits.

Definitely not recommended.

However, we're talking distilling and not beer here. You probably don't need 2400W once the wash has been brought up to temperature. The main advantage of more electrical oomph is a shorter waiting time.

My boiler has a 2400 w element, and it takes about 75 minutes to boil up 40 litres of 40%, from a starting temp of about 25-27 C. A little slow, but 2400 w is a very convenient size element in Australia/New Zealand, as you can plug it into any standard power socket (10 amp) in those two countries.

An immersed element is way more efficient than an external hotplate of the same wattage, because it doesn't lose heat to its surroundings.

Big plus of immersion elements.

[muckanic]

My boiler has a 2400 w element, and it takes about 75 minutes to boil up 40 litres of 40%, from a starting temp of about 25-27 C. A little slow, but 2400 w is a very convenient size element in Australia/New Zealand, as you can plug it into any standard power socket (10 amp) in those two countries.

Even with 2400W elements, I still like to use 15A cable and fittings for a bit of wriggle room. The gotcha there is the wider earth pin having to fit into the wall outlet, so one or the other must be modified. Prolly illegal, voids the insurance and all that sort of stuff, but possibly not so significant in the grand scheme of things ...

[HookLine]

Even with 2400W elements, I still like to use 15A cable and fittings for a bit of wriggle room. The gotcha there is the wider earth pin having to fit into the wall outlet, so one or the other must be modified. Prolly illegal, voids the insurance and all that sort of stuff, but possibly not so significant in the grand scheme of things ...

Standard 10 amp cable can actually carry a much higher load safely (but it is not recommended you actually do it!). All standard power cables are de-rated, meaning the capacity they are legally allowed to carry is a lot lower than they can actually safely carry. It is done because the electrical authorities know from long experience some damn fool somewhere will load up the poor old cable well above its rated working limit, and also to allow for temperature effects on the cable's carrying capacity (higher temp = reduced capacity).

IIRC, the standard 2.5mm^2 power cable that is used in Australia/NZ for the built in wiring in your house is actually capable of safely carrying 27 amps continuously, and the breaker/fuse for the standard power circuits (with 10 amp outlets) is rated at 20 amps. So there is a large margin of safety built into the whole system.

Really would not be messing with the 15 amp earth pins, they are incompatible with 10 amp sockets for a very good reason. Any approved 10 amp cable/plug/outlet will safely carry 10 amps continuously, there is no real advantage in using 15 amp for 10 amp loads. The cable might feel a little warm when running at maximum rated capacity, but that is normal and quite safe. Just do not have the cable all tightly wound together, as this can cause the heat to build up. Leave plenty of space around the cable for the heat to dissipate off easily. Also keep any extension cords as short as possible, to keep electrical resistance down.

Many household extension cords are only rated for 7.5 amps, so watch out for that. It will clearly state the carrying capacity on the label.

[MashMan]

This is the steam inlet ring that sits in the bottom of the mash tun.

It's a bit hard to see how many holes you have in it but, as I have speculated before, that sort of thing could also function as a manifold for draining the mash tun when sparging beer. I take it you use a separate drainage system? Does the steam dilute the mash much (assuming you are mashing in at at least 40C)?

Hi muckanic, I guess I do things a little different than whats considered "normal" I do have a s/s braid that fits in the same place as the steam ring, I can use it for both steam and drain but its not often that i dont ferment on "some" grain. I find the braid doesn't work well with corn, the starch gets into it where it doesn't get exposed to enzymes and clags up the braid/pipe.
The pics I posted are from a while ago, the tun now has a 1 1/2" drain in it,I guess my tun is a cooker more than anything else, I usually cook up 3 or 4 batches one after the other, drained grain and all into a bop, the faster its out of the cooker the sooner the next batch is going.The bop has a large volume compared to surface area so no fancy insulation is needed. I find batch after batch into bop with no insulation leaves me enough time for a good clean up after a day of cookin and the temp is (well this time of year anyway) almost low enough to add enzymes/malt etc otherwise 18m of 3/4" copper immersion chiller works great just keep stirin.
once converted I drain off wort, divide between 2 fermenters and add about 1/6th of the grain to each fermenter this way my fermenter is not 1/3rd full of grain and I find I get a better product/flavour than fermenting wort only. the remaining grain is sparged and this water is used when next cooking.
when cooking corn for example I lose somewhere between 6 and 8L of water from the boiler but wouldn't gain that much in the cooker as its lid aint to fancy, anyways its no big deal after a batch or two you know what to expect.

cheers.