StillSmart

OK, I'm just about ready for a new project and thought maybe we could make it a collaborative effort.

My plan is to build a still using a 30l or 50l vessel, perhaps a keg, with a heat exchange coil fed from a small condensing boiler and/or solar water heater panel thereby seriously reducing the power consumption by feeding hot water to the small boiler.

Another advantage to this type of still would be that the max temp of the heating 'element' would e 100oC so less chance of off flavours caused by burnt solids from the wash.
( got my thinking cap on now )

The idea being that the volume of water to be heated for the heat exchange coil would be relatively small and with a suitable condenser fitted to the coil outlet the exiting vapour would be returned to the small boiler.

Thing is, I have no idea about the mechanics of such things as heat exchange coils, what size boiler would be required, would it need a circulation pump, am I talking through my arse?

Anyone want to pitch in expertise, experience, drawings, plans, etc?

AM

Don't think about it!!!

It's far to hard - in the industrial steam heated applications they use highly pressurised steam which is a lot hotter than 100 deg C. Pressurized steam is something that I would not recommend in your lovely workshop.

Now if you want to stop scorching then a glycol jacket on you boiler may be worth a crack.

Aidan,

Have a look at this thread.

http://www.artisan-distiller.net/phpBB3 ... =45#p92277

Aiden,

I agree with Brian.

I'm no expert in this either, but thinking of basic physical mechanics;

1. To use a small condensing boiler specifically for this purpose will probably be less efficient then a direct heat source, as nothing is 100% efficient. If the heat source were to be a by-product of something else then I can see then benefit. ie a loop feed from the back of your central heating boiler, AGA, Rayburn etc

2. I don't know of a domestic water solar system that will generate heat to 100degC to produce the temperature you aspire to. There are commercial systems but the costs and specific requirements and pressures of these are prohibitive for a domestic system.

3. Dependant on piping arrangements, hot fluid rising and cold fluid falling, it will almost be a given that a circulatory pump of some description will be required.

For an idea of power required the best and closest item I can think of would be the power and steam effort required to heat your thumper. This is basically what you will be achieving, with the exception that it will be a closed system.

A few of the other regulars have steam wand's and the like for mashing, they will be better placed than I for a confirmation of the power requirements to achieve these temperatures.

You can make a solar hot water system that is not steam.... there are a number of systems that can be home built... just big box panels Mother Earth Magazine would have plans i bet if you can't find em on the net..

All depends on your available time and if you have good access to the sun and cheap surplus parts ....

There are instructables on the net as well for this .... worth a look

I replied earlier but it seems to have got lost.

I agree with the above. If I had steam available I would use it without question, at about 120 deg C. But I would be using the steam to heat everything in the brewery and still room - probably from a gas fired boiler.

But to generate steam for 1 still only is probably not economically viable. You can get standalone electric jacketed steam boilers, but they have an element inside the jacket.

For the circulating system you proposed, you could use pumped glycol. I believe there are pumps that can cope with glycol at about 110 deg C. Circulating at just 100 deg C is not really worth doing, you need to increase the thermal gradient.

Just try sitting a can of water inside a pot of water on the stove and see how long the inner container takes to come to the boil.

That's the entire point about using steam - the increased thermal gradient. Even steam at 100 deg C releases more energy than just water at 100 deg C but lifting the temperature 10 to 20 degrees higher makes a huge difference.

On my glycol boiler I intend to run it at about 115 to 118 degrees as it starts to degrade above 121 degrees.

Interesting project Aidan but if anyone doesn't need a rig like that it's you. Probably all the more reason for you to want one.

I was thinking of something on the lines of a stainless steel amazingstill.

Although very slow, it gives high quality product but I stopped using mine as soon as I learned of the dangers of plastics.

A beer makers type copper worm fitted to the lid of a large SS stockpot so it fits into a 10L stockpot inside, plastic tube running from the coil to an insulated tub of water, a 300w aquarium heater (or 2) modded to give 55'C and a small pump.

It taking multiple days per litre of product is no never mind if other stills are available.

You could use a hot water bath?
It seems high pressure steam has been knocked on the head due to energy input, and the fact that steam starts at 100c and goes up from there, scorching is possible.
Even a flash boiler would have trouble, although safer, they are power hungry, and lots of condensate.
Glycol has merit, but the enclosed systems, pumps and plumbing cost lots.

A hot water bath, double boiler style never tops 100c (unless your in the hills), and can be heated conventionaly. Not too hard to make, and if your a bit of a scrounger, even cheaper.
Relatively safe too.

I haven't posted it on this forum yet but I will put it in the Build Your Own section later. My glycol boiler is a double boiler as described just above.

The outer boiler is a big old aluminium pot with a 3kW element. I insulated this. The inner used to be a stainless 20 litre stock pot, but I am building a new copper inner pot for it.

It is easy to get the glycol to 130 degrees centigrade - this is the equivalent of 3 bar steam - but at atmospheric pressure.

However I would not go higher than 118 with a target of 115 degrees C, because I have found that the glycol starts to degrade at 121.

For the home builder I have to recommend glycol. It gives you the increased thermal gradient with no pressure problems, is easy to use and easy to build for.

The copper inner sounds nice Miles.
I guess the added temp that glycol can run at would be a benifit on some products.

I guess if the lower cost of using water is out weighed by a need to reach higher temps than water can give then glycol would be the go to medium.

Ideas need to get tossed about to test their advisability and do-ability This is obviously one horse that will not run. Not for me anyway

Perhaps this thread will spur other useful and more practical development ideas.

AM

emptyglass wrote:The copper inner sounds nice Miles.
I guess the added temp that glycol can run at would be a benifit on some products.

I guess if the lower cost of using water is out weighed by a need to reach higher temps than water can give then glycol would be the go to medium.

Let me just qualify this a bit. If I could distil outdoors and the steam leakage between the inner and outer pots was not an issue, then I would use a simple double boiler with water and steam as the thermal fluid.

Use such a device indoors however, and all you do is to convert your still room into a sauna.

For indoor, indirect heating, glycol is a decent self build alternative. I reserve mine for use when there are some sort of solids in the boiler, and could not use a standard immersion heater.
In the future it will be used for gin and also as a strip boiler for fruit pulp. I will let the fermenter settle, rack off the clear wash into containers and then strip the rest as an alternative to using a fruit press to extract the fluids.

aidanmac wrote:OK, I'm just about ready for a new project and thought maybe we could make it a collaborative effort.

My plan is to build a still using a 30l or 50l vessel, perhaps a keg, with a heat exchange coil fed from a small condensing boiler and/or solar water heater panel thereby seriously reducing the power consumption by feeding hot water to the small boiler.

Another advantage to this type of still would be that the max temp of the heating 'element' would e 100oC so less chance of off flavours caused by burnt solids from the wash.
( got my thinking cap on now )

The idea being that the volume of water to be heated for the heat exchange coil would be relatively small and with a suitable condenser fitted to the coil outlet the exiting vapour would be returned to the small boiler.

Thing is, I have no idea about the mechanics of such things as heat exchange coils, what size boiler would be required, would it need a circulation pump, am I talking through my arse?

Anyone want to pitch in expertise, experience, drawings, plans, etc?

AM

Hello friend thread is bit old but have you got the solar vessel system? Even I am searching for similar set up so please share your own experience.

Sorry Raul, I should have posted something here to indicate that the idea was abandoned on advice from other more knowledgable members who advised against such a project on the basis of safety.

AM

aidanmac wrote:OK, I'm just about ready for a new project and thought maybe we could make it a collaborative effort.

My plan is to build a still using a 30l or 50l vessel, perhaps a keg, with a heat exchange coil fed from a ] condensing boiler and/or solar panels water heater panel thereby seriously reducing the power consumption by feeding hot water to the small boiler.

Another advantage to this type of still would be that the max temp of the heating 'element' would e 100oC so less chance of off flavours caused by burnt solids from the wash.
( got my thinking cap on now )

The idea being that the volume of water to be heated for the heat exchange coil would be relatively small and with a suitable condenser fitted to the coil outlet the exiting vapour would be returned to the small boiler.

Thing is, I have no idea about the mechanics of such things as heat exchange coils, what size boiler would be required, would it need a circulation pump, am I talking through my arse?

Anyone want to pitch in expertise, experience, drawings, plans, etc?

AM

It is great idea.. I am bit worried about expense.. Here there is very less sunshine available so it is hard to use solar water heater.