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im wondering if anyone has tried steam distillation or vacuum distillation id be interested to know the drawbacks and benefits thx guys

Welcome to the forum ... If you do have experience using those methods we do hope you post it, if and when you can...
If not post your trials and tribulations during your educational journey...

Happy Stillin

FS

My limited experience with vacuum distillation, began and ended with a sucked flat corny keg.
I'm too afraid of steam heat to use it the real distillers do.
In my opinion anything over 1psi is too dangerous for me to be playing with.
Indirect steam injection works great for cooking corn and might be safely used for distilling.

IMHDO the D is for drunk, It will definitely lower the abv when used for distilling.
The problem is, 212f steam heat isn't very efficient at heating a water/alcohol mix to boiling.
For cooking at 200f or below, steam injection is very good.

shadylane wrote:IMHDO the D is for drunk, It will definitely lower the abv when used for distilling.
The problem is, 212f steam heat isn't very efficient at heating a water/alcohol mix to boiling.
For cooking at 200f or below, steam injection is very good.

I use steam injection for distilling on the grain and it works very well. It does lower your ABV. It takes about 15% of your initial volume on condensed steam to bring the mash to a boil. If you started with 10 gallons of mash, you would have to inject about 1.5 gallons of water to get it boiling. So if you had an 8% abv to start, you might be looking at 7% abv with steam injection. I think it is perfect for stripping runs on the grain.

From a safety standpoint, steam injection is just like running a thumper. The steam is actually incredibly efficient at heating your mash because when steam bubbles enter your mash, they collapse and condense and give up their energy while they change phase from vapor steam to liquid water. The inefficiencies in my system come from the fact that none of my rig is insulated. I heat water in a keg with an internal element, make steam, pipe it into the bottom of another keg filled with mash and a still attached. The kegs radiate a good bit of heat from their sides, and since my copper steam lines aren't insulated, some of the steam condenses in the pipe that carries it, lowering efficiency.

The old Carolina Steamer Stills used direct steam injection and worked quite well with no real concern of scorching the mash.

My little 1gallon pot still was actually the steam generator for a 5 gallon steamer still in it's previous life. That still worked really well too. I simply went bigger and stopped using it. I thought it came up to temp pretty quick, and distilling on the grain isn't a bad thing. I should probably go dig that thing out and start using it again.

The only real drawback I'm aware of is the steam dilutes the mash and lowers abv slightly. It's not a huge issue, and may be worth it to distill on the grain.

Steam injecton distilling is tried and tested.

In my ideal still room all my stills would be steam heated and my strip still would most definitely be steam injected. Don't forget that once you get past heat up, injecting steam does NOT dilute your product abv.

Yes there is dilution of the boiler charge on warm up, but it is easy enough to factor this in to your calculations.

That's true that once you are boiling, it doesn't dilute your product abv if you are only running it as a simple pot still. Running a reflux rig with steam injection isn't ideal though because you are condensing more steam into the mash than you are giving off in alcohol vapor. It wouldn't be good to set it up in full reflux for 30 minutes while you were injecting steam. It does work great for stripping thick, grain-in mashes.

myles wrote:Don't forget that once you get past heat up, injecting steam does NOT dilute your product abv.

Hi Myles,

Please help me understand your statement.

I think the only way to prevent dilution, of the product abv, is to insure that all of the injected steam condenses in the boiler charge.

How do you do that?

DeepSouth wrote: Running a reflux rig with steam injection isn't ideal though because you are condensing more steam into the mash than you are giving off in alcohol vapor. It wouldn't be good to set it up in full reflux for 30 minutes while you were injecting steam.

Hi DeepSouth,

Help me understand your statement.

I think that the column of a reflux still could knock down the additional water that is introduced into the vapor when injecting steam. However, I think the column would need to be longer, than otherwise, in order to handle the additional water.

Lampshade, if you want to learn more about steam engineering, this website is a good resource. It has tons of information, and there is even a section on steam injection.

http://www.spiraxsarco.com/Resources/Pa ... ction.aspx" onclick="window.open(this.href);return false;" rel="nofollow

If you ran it way too hard, it is possible for the steam bubbles to not have time to fully condense into the mash and for some of them to continue rising up through the mash and up the column as water vapor. However, if you have a good design for your steam injector (mine is designed like a sparge pipe as shown in the figure on the link above), then the steam will fully condense in your mash and none will escape up the column. Because steam has a higher latent heat of vaporization (i.e. amount of energy transferred per unit weight during liquid to vapor or vapor to liquid phase change) than an alcohol water mixture, a given mass of steam condensing in the mash will actually boil off a LARGER mass of alcohol-water mixture. If you take into account the densities of water and alcohol, if you are already at a boil, 1 gallon of water that has been added as condensed steam will actually boil off more than 1 gallon of a water-alcohol mixture.

As far as reflux goes, say you have a dephlegmator and were running full reflux, sending everything back to the boiler. You are continually adding heat in the form of condensing steam, but none of the vapor that is being produced is allowed to escape and be collected. So the %abv in the mash will continue to be further and further diluted. If you were trying to get your reflux column equalized and compress the heads, you'll have a hard time. As the abv in the boiler is becoming more and more dilute, so is the vapor that is being produced, which may pose a problem for column equalization while you are trying to compress heads.

The real benefit of steam injection is the ability to distill thick mashes that would scorch under other heating methods. It is also much cheaper to build a steam injection system than a steam jacketed system, and the only pressure in the system should be due to the height of liquid in the still boiler. A keg still with 24" of liquid in the boiler would operate at less than 1 psi for a steam injection system.

Thanks, DeepSouth,

The picture you referred to shows a temperature sensor and controller. Do you do that?

Also, do you use steam injection with a reflux rig? If so, do you switch to electric heating during the equilibrium phase?

What kind of fittings do you use to inject the steam?

lamp

No, I don't use any kind of temperature sensor. I heat the water and make steam in one keg with an internal electric heating element. I have a phase angle controller for the element. This allows me to control the amount of steam produced. I have a 4 plated flute. I send water to the dephlegmator initially, just to get liquid on the plates stacked up, but I don't run full reflux for any extended period of time. Once the plates are loaded, I can run it without much reflux at all.

This picture should give you an idea of how it is setup. I have a central keg with the internal element. The keg on the left is the mash cooker, and the keg on the right is the still boiler. The steam injection plumbing is identical on the mash cooker and still boiler. I have a blowoff/bypass valve for the steam. I leave the valve open during water heat up and when steam starts coming out I close the valve and let it pass into the still. You can definitely hear it. The collapsing steam bubbles in the mash make a lot of noise.

Yeah, it wouldn't hurt to have one, but it is under the same pressure as all the thumpers people run. Literally less than 1 psi. When you run one, you can hear it working the whole time. If it isn't making noise, then you've got a problem.

DeepSouth wrote:Yeah, it wouldn't hurt to have one, but it is under the same pressure as all the thumpers people run. Literally less than 1 psi. When you run one, you can hear it working the whole time. If it isn't making noise, then you've got a problem.

Your right, direct steam injection is basically a thumper.
For the folks that are thinking about using direct steam injection, here's my 2 cents worth.
I use a 15 psi steam rated relief valve, with a home made manometer that measures and limits the pressure to under 1psi.
Also there's a manual valve that can be opened to vent pressure or a vacuum.

edited:
I use a manometer on every pot I use.
Shit happens, holes and outlets plug-up.

My steam kettle is simmilar in principle to the one shown above. Just gass powered and shrouded. I also have a valve on the outlet line so mine has a 3 bar psv between the 2 valves.

Mine was set up so I can deliberately close both valves to build up pressure to empty the keg in the conventional way. My drain system has a dip tube to the bottom of the keg, just like a keg spear. My psv also has a gauge on it for a visual pressure indication. thats an old photo as it now has a fancy concrete insulation on the shroud

Here's some pic's taken before I replaced the hose with flexible copper tubing.

On the subject of using direct steam injection for reflux still operation, a quick calculation shows that 3kW = 1g/s = 4.7L/hr, for 2300J/g of latent heat. So more than a gallon of water is added for every hour of operation (minus what you condense, of course). Even super-heated steam (like from a flash boiler) will not do much better.

waster wrote:On the subject of using direct steam injection for reflux still operation, a quick calculation shows that 3kW = 1g/s = 4.7L/hr, for 2300J/g of latent heat. So more than a gallon of water is added for every hour of operation (minus what you condense, of course). Even super-heated steam (like from a flash boiler) will not do much better.

I don't understand that. What do you mean by "more than a gallon of water is added for every hour of operation?" Where is this water added? To the boiler charge, perhaps? And what is the relevance for reflux still operation?

As you probably have guessed by now, I'm really struggling with this concept. As I envision steam injection, steam is introduced in the bottom of the boiler charge: Some steam is condensed (thereby adding water to the charge) and some steam rises and makes its way to the column. If the rig is a reflux still, the column condenses the steam and the water falls back into the charge. If the rig is, instead, a pot still, then the steam is also condensed, but, instead of falling back into the charge, goes out as part of the product (thereby lowering the ABV).

Is my description correct? Or, instead, does all of the steam condense in the charge and none rises to the column. If that is the case, how does one control the injection so that none of the steam rises into the column?

Deepsouth, excellent link. Thank you.

I've been making gin by combining the botanicals and neutral in my thumper and using the primary boiler for a steam generator. An idea I got from Myles, in fact. It works great.

My question for all of you is what do you use for the sparge pipe or nozzle?

And do you think all of the steam is being condensed before it escapes thru the top of the still charge?

EDIT: typing while lampshade posted.

From what I gather from the paper deepsouth linked to, the things you do to increase the amount of steam that gets condensed are;
Maximize the level of liquid above the nozzle.
Use a sparge pipe or nozzle that makes small bubbles, and
Keep the steam pressure as low as possible.

The question, then, would be How to tell how much is being condensed. I think you could calculate it from the changes in volume in the different containers. It would take some thought. One of these guys probably has it figured out.

Seeing as how the boiler charge would be below the boiling temp of water. I would imagine all the steam would be condensed.

lampshade, yes--I think people who build direct steam injection intend for ALL the injected steam to condense by the time the bubbles reach the surface of the boiler. Not sure how easy it is to ensure that .... My calculation is for reflux because: everything else being equal I might run a pot still at 1-2kW and add just a couple of liters of water to the boiler charge for each hour of operation. Another way of looking at it, simplified, is that for a 3:1 reflux ratio run, I'll need to run at the same power as a pot still for 3-4 times longer OR at 3-4 times the power with the same duration. Basically, the energy needed for a potstill run is 1/RR compared to a reflux run on the same wash.

I'm just guessing here--never tried direct steam injection, a flash steam boiler, or any other steamy option.

When I use steam injection in the mash cooker, I can see the top of the liquid because it's an open vessel. I use the steam injection to bring my mash water to a boil. I'll start with about 8.5 gallons of water and by the time the water is boiling it is close to 9.5-10 gallons. When the mash water is around room temperature, the bubbles never escape all the way to the surface. The largest temperature gradient exists upon initial heat up so the steam bubbles have the best chance of fully condensing.

The sound changes as the water continues to heat up. The way the bubbles collapse definitely changes as the temperature gradient changes between the steam and mash water. I have a short video of the rig running I'll try to upload. When it starts out it is really loud and sounds almost like a pack of firecrackers going off. When it is boiling the steam injection sounds like a dull roar.

[img]http://i1064.photobucket.com/albums/u364/dwrich1020/Mobile%20Uploads/IMG_20141213_175525842_zps942ed25f.jpg[/img]

[img]http://i1064.photobucket.com/albums/u364/dwrich1020/Mobile%20Uploads/IMG_20141213_175502262_zpsf8b4a158.jpg[/img]

[img]http://i1064.photobucket.com/albums/u364/dwrich1020/Mobile%20Uploads/IMG_20141213_175325086_HDR_zps64f90607.jpg[/img]

My injector is just 1/2" copper pipe. I crimped the end but it isn't completely closed. There are a total of sixteen 1/16" holes. I read somewhere that the total area of the holes in a sparge style injector needs to be roughly equal to the cross sectional area of the pipe. I have 8 holes angled downward in one direction and 8 angled downward the other direction. The angle between the holes is about 90 degrees. If straight up was 0 degrees, the holes are roughly at 135 degrees and 225 degrees.

I know this is an old thread but maybe I'll get lucky - does having a roughly vertical pipe eliminate solids in the steam injection arm? I used to try steam cooking my grains (no still heating though, I did a lot of mesh bag straining and ran it on propane). Made a nice little pinwheel shape with a bunch of vertical holes to let steam escape upward into the mash. It would sit at the bottom of the pot and I'd bubble steam into it... worked nice but the steam wand flooded constantly. I soldered on a threaded fitting to the end and capped it with a stainless plug, but it was kind of a mess and by the end of the run half the holes were plugged anyway. I'm thinking of building another arm, this time with a tri-clamp fitting to deliver it through the top of my keg boiler at a near-vertical angle. Planning to do a ton of 1/16" holes into a 3/4" pipe.

When your run is done, how dirty is the inside of your steam injection pipe?

pope wrote: ↑Fri Sep 20, 2019 12:42 pm I know this is an old thread but maybe I'll get lucky - does having a roughly vertical pipe eliminate solids in the steam injection arm? I used to try steam cooking my grains (no still heating though, I did a lot of mesh bag straining and ran it on propane). Made a nice little pinwheel shape with a bunch of vertical holes to let steam escape upward into the mash. It would sit at the bottom of the pot and I'd bubble steam into it... worked nice but the steam wand flooded constantly. I soldered on a threaded fitting to the end and capped it with a stainless plug, but it was kind of a mess and by the end of the run half the holes were plugged anyway. I'm thinking of building another arm, this time with a tri-clamp fitting to deliver it through the top of my keg boiler at a near-vertical angle. Planning to do a ton of 1/16" holes into a 3/4" pipe.

When your run is done, how dirty is the inside of your steam injection pipe?

Dunno how skilled you are at fabricating?
But if you were able to fab up a steam eductor head and install into your cooker on an tangential orientation you could also insure good agitation/heat distribution as well. Mount low and horizontally to insure that all of your steam gets knocked down.

pope wrote: ↑Fri Sep 20, 2019 12:42 pm Planning to do a ton of 1/16" holes into a 3/4" pipe.

1/16" size hole in the 3/4" end pipe might just be on the small size.. I use stream to strip my AG with and the down pipe is 1" off 1 1/2" from the boiler, with foot piece being 3/4" and use 5/16" holes spaced about 1/2" apart on a 4 lines across the pipe on the down size.. never had a problem with holes plugging, and heat up is very fast less than 10 min to heat a 6 gal mash..

for the thumper I use the same setup except the foot piece has 3/16" holes on a 3/4" pipe of the sample pattern.. and that heats the thumper real fast, less than 4 min..

Mars

I ran it for the first time last night, my steam wand/arm is drilled through both sides of the pipe with the 1/16 in roughly 3/8 spacing with 45 degree offset, the result was a spiral of holes - lots of holes, not sure how many. Way less than it takes to equal the square inches of a 3/4" pipe opening. The bottom is crimped but poorly so there is room for steam to escape (roughly two 1/4" diameter openings, more teardrop than round). I clamp the steam arm to the top of the keg with an off-center 1-1/2" tc fitting, the result is the tip of the arm comes 1/2" shy of touching the drain hole in the bottom center of the keg. Steam holes come up about 8" off the bottom of the boiler, so I figured 7+ gallons of charge will keep them covered.

Once the boiler charged, the heat up was very quick! For 8 gallons it took maybe 15 minutes to first drops. I did notice my head temp seemed a little higher than normal stripping runs, but my yield seemed good - I didn't have reliable measurements to compare abv with the low wine yield, but I have a more precise batch in the fermenter and will have another go next week.

I've separately been considering a chugger pump for agitation, with an inlet and outlet on opposite sides of the keg wall about 4-6" up from the bottom of the volume. I am moving pretty much to only flours so while they're too thick for direct heat with an element, they're not too thick for a chugger to keep them moving, especially once they heat up and become less viscous and are steam-diluted.

FWIW re: dirty steam pipe, it rinsed clean up to the liquid line in the boiler, but the fine flour bubbles inside cooked onto the outside of the steam wand. Cleaning this AM it wipes off easy enough with a sponge, but that wasn't anticipated.