inline stripping flange

[Stew8]

Likewise, a great post, I’ve cut a 3” hole in the stainless lid and I’m making time to progress the stripper..,

[Evil Wizard]

Yeah silicone defoamer is usually added to the boiler but we don't always have a boiler in a continuous setup. I guess put a couple drops in wherever your element is and it should float there. I haven't honestly tried this myself in a continuous since I'm just doing sugar runs for now.

[Yummyrum]

I read somewhere that the commercial guys inject it ( de-foaming agent ) at a metered rate at the feed point .
It would be a very small injection rate concidering how little we stick in a boiler full normally .

[Seb]

Hello everybody, please can you tell me which of these boiler wash outlet design is better?

[OtisT]

I read somewhere that the commercial guys inject it ( de-foaming agent ) at a metered rate at the feed point .
It would be a very small injection rate concidering how little we stick in a boiler full normally .

This will take some work, feeding micro amounts of that stuff at a metered rate. The silicone de-foaming agent I currently have is a 10% concentration and the quantity needed for an entire boiler full is measured in drops. Maybe I can find a more diluted product that will help control a slow dose better.

As a starting point I’m thinking of a sight glass just above the wash input ( to see foaming) and a small hole in the column above that sight glass for inserting a borosilicate glass eye dropper. (And a plug for the hole when not in use.) Once I understand the rate, I can think about a more automated solution.

This rabbit hole is getting deeper.

[OtisT]

IMG_20180709_101747.jpg

Hello everybody, please can you tell me which of these boiler wash outlet design is better?

Hi Seb. My opinion is based solely on reading, so consider the source......

As drawn, both will work the same. You will want the ability to adjust the height of the output tee, to tune your system for the varying amount of pressure you will be dealing with.

I think the lower straight pipe would be better for two reasons. First, there are no permenant tubes in your boiler to deal with (cleaning, internal element clearance, etc.). Second, that lower port would be more useful for other purposes if this experiment fails. I plan to make an auto drain that simply clamps onto an existing ferrule port.

Otis

[Seb]

I think the lower straight pipe would be better for two reasons. First, there are no permenant tubes in your boiler to deal with (cleaning, internal element clearance, etc.). Second, that lower port would be more useful for other purposes if this experiment fails. I plan to make an auto drain that simply clamps onto an existing ferrule port.

Otis

Thanks Otis.

[Seb]

Hi,

I am new in this forum, however not new in the distilling. I used to do it long time ago and recently after some time of watching the forum I am just about to start again.
It looks like this moment is perfect to enter the forum as I always was using the continuously run column.
Now that I saw that there are more people interested in that I would be happy to share some of my experiences.
First of all I must admit that in continoous disilling there is much more engineering than art. Hoever there is still plenty of enjoyment.
The invention presented by absinthe is great and very helpfull. Still there are some ways of improvement which are simple and reliable (don't bother with any valves):
1. Install a liebig type heat exchanger to preheat the wash by means of spent one coming out from the boiler. Assuming that you pump into the column 10 litres/h of wash you can save (gain) practically 0,8 kW of heating power, and the same time getting spent wash going out in acceptable temperature of 40 deg. C - which doesn't evolve to much smell.
2. You may use really small boiler (intead of keg you can use a household kettle with a volume not bigger than 1 - 2 litres). The great advantage is that you don't have to heat up the big amount of liquid at the start up.
3. The best is to use a feed pump (for example peristaltic) and then after the start up and getting the column running in stable conditions you may go to sleep (of course I would not advise it). On the other hand this is where the beauty is - the installation may be small but still capable to process any amount of wash in one (long) run.
4. If you are afraid of loosing alcohol with the spent wash you may install a stripping section of the column below the feedeng point. This is quite importan when one would like to make a "second strip" using feed of more than 40% of alcohol.

I hope my post is sent and received correctly (this is my firs time) but if yes and moreover if there is anybody interested please let me know and I will try to make a drawing of the installation I used to run for years an with a great success.

Gentlemen. I am about to build a continuous still based on this model, more or less. But in my case it will be a column of 4 inches in diameter x 118 inches in height. As a boiler I have the choice between a 30 litres beer keg or a 10 litres beer keg. I feel a bit strange to use such a small keg like the 10l one, it's only 10 inches large x 10 inches high and only 5 litres of wash would boil inside. The 30 litres feels more adequate to me but following Andre, the smaller the better. What would you chose? My heating source is direct fire with free biomass, no concerns about consumption.

[Stew8]

In theory this works, I built it and it failed ..and in hind sight it’s obvious - not enough heat....so I’ve disassembled it to play with on a rainy day.

In my view here is the crux of the problem; (sorry it’s metric)
if you’re collecting say 60ml a minute at 80% ABV that’s about 50ml a minute at 100%
If my wash is 10% I’ll need to feed 500ml (1 pint) a minute, to get a run rate (above). The wash needs to heat up to 80c from room temperature around 20c.

Shifting half a litre of wash 60C in a minute takes more power than I have at the moment.
Using the calculators (below) I could raise 500ml 60c in a minute with 2kw heater, which is more than my current heating element in the boiler.
http://processheatingservices.com/water ... alculator/

The new design will need to have a preheating boiler that basically supplies the wash at 80c and will have little impact on the tempterature of the still itself. As I’ve found, feeding “cold” wash into the top of the column rapidly reduces temperatures both in the column and in the boiler itself.

The joys of experimentation

[Stew8]

Just ordered a 9kw gas ring.

[Seb]

In theory this works, I built it and it failed.... Just ordered a 9kw gas ring.

I missed this thread. Stew, how is it working now?

[Lummel]

About pre-heating your wash, I would design it in such way that the wash is heated by the bottom product leaving the boiler. You could recover a lot of heat that way.

Edit: this was already mentioned above, missed it, my bad.

[Stew8]

Not had time to play, life is in the way but I’ll get there. It’s a cold dark winter in the frozen waste lands of the north
I’m sure some in the highlands may disagree.

[The Baker]

About pre-heating your wash, I would design it in such way that the wash is heated by the bottom product leaving the boiler. You could recover a lot of heat that way.

Edit: this was already mentioned above, missed it, my bad.

Charentais still. Google it, lots of pics.

Geoff

[Seb]

In theory this works, I built it and it failed ..and in hind sight it’s obvious - not enough heat....so I’ve disassembled it to play with on a rainy day.

In my view here is the crux of the problem; (sorry it’s metric)
if you’re collecting say 60ml a minute at 80% ABV that’s about 50ml a minute at 100%
If my wash is 10% I’ll need to feed 500ml (1 pint) a minute, to get a run rate (above). The wash needs to heat up to 80c from room temperature around 20c.

Shifting half a litre of wash 60C in a minute takes more power than I have at the moment.
Using the calculators (below) I could raise 500ml 60c in a minute with 2kw heater, which is more than my current heating element in the boiler.
http://processheatingservices.com/water ... alculator/

The new design will need to have a preheating boiler that basically supplies the wash at 80c and will have little impact on the tempterature of the still itself. As I’ve found, feeding “cold” wash into the top of the column rapidly reduces temperatures both in the column and in the boiler itself.

The joys of experimentation

And now that it's more than a year, did you get some results? I plan to do that but with direct biomass fire, so there should be no power problem.

[Seb]

Hello everyone. If I use the boiled wash pouring out of the boiler wash outlet to preheat my wash, one litre per minute of nearly boiling wash will preheat one litre of wash. Same in same out as it's the wash entering the boiler that pushes the boiled wash away. What temeprature will be the preheated wash? Do you just make an average betweeh the 25ºC of the wash and the ~95ºC of the boiled wash to get the temperature, namely 60ºC?

[still_stirrin]

...Same in same out as it's the wash entering the boiler that pushes the boiled wash away. What temeprature will be the preheated wash?...

You need to balance the heat transfer equation, ie - heat out of the draining liquid + ambient losses = heat transferred to the incoming wash.

If the mass flows are equal and you assume the coefficient of heat for the draining liquid and the incoming liquid are the same (a good, not great assumption), then the heat transfer says the temperature changes for the liquids should be equal, or nearly equal because of the heat loss to the ambient air.

So, if you measure the temperature of the draining liquid as it drains, and you measure the temperature of the draining liquid after the preheat heat exchanger, and you measure the temperature of the incoming liquid’s reservoir, you can predict the temperature rise of the incoming liquid through the preheat HEX. But, it’ll be close..because of the inefficiency of loss to the ambient.

Now, one assumption which may be askew is that the coefficient of heat for the draining liquid and the incoming new wash will be the same...they probably won’t because of the alcohol being boiled off. But to approximate the continuous process and simplify the equations, I would make that assumption.

Another tricky assumption is that the mass flows (which is required for the heat transfer equations) can be assumed to be equal when their “volumetric” flows are equal. This may be a grave assumption except that they are both liquid “fluids” such that their densities are very, very nearly equal...at least within the accuracy of the accummulated measurement errors. So again, I would assume the mass flows to be equal if the volumetric flow rates were equal.
ss

[Evil Wizard]

It seems from my experience that it is much easier for the incoming wash to gather heat from the alcohol vapour but there is so much more heat in the exiting boiler water. Its actually difficult to gather it all without a large dephlagmator. Im ordering a 19" long 6" deflag with another 8" deflag for secondary water cooling to prevent steaming up the room.

Currently im breaking 22.8 Lph of vodka output at 62%abv. Basically 100L of wash to 20L of vodka in 60 min on 10750 watts. My unit is only 5 feet tall and has an 18" square footprint. Im very pleased with how ive spent the last 3 years in my garage.

[Yankle]

Hi E W, do you have a picture or clip of the latest striper?
thanks, yankle

[Evil Wizard]

As requested, here are some pics of the latest 6" continuous stripper build. I'll be replacing the boiler exit heat exchanger to a copper shotgun when I find a new garage to work in.

[Yummyrum]

Thanks for sharing Evil wizard . Thats an impressive looking setup ..... but how it works is clear as mud

Any chance of a diagram as to what you have there and why

[Seb]

This is probably a stupid question but do you think the third design will work as well as the previous ones?
It's much simpler. There is no vent either.

[Yummyrum]

They will all work Seb . The underlying principle is to have a fluid lock between the boiler and the atmosphere .
This is my first attempt . I was using a 10% Feints mix . the waste was exiting very smoothly . I wondered why do we need a vent ?

Then I got excited and tried a Rum wash . Well it all turned to shit real quick as the Rum foamed and pucked and when the wash had made it to the re-boiler it was still nasty . I had sticky Rum Dunder splurting out the vent making a right o'l mess

So I quickly jambed a pipe I had lying about to save the day .

Now the reality is that its next to impossible to get a continuous stripper to work alone simply by using the Vapour (PC) Pre-heater as there just isn't quite enough energy available to heat the wash .This is a sad reality to all those that think they can follow one of the many "simple" designs that are floating around the forums ....it is also why you rarely here of any success building a continuous stripper .The principle looks good in paper but in reality it won't work .
So I added a Bottoms heat recovery Heat exchanger as well to give the wash an extra boost . This pic will probably confuse the hell out of you as you can't see whats inside the HX but its basically the same principle as the first as regards to exiting wash .

Basically there still wasn't enough heat gain so I tried my 6' Liebig as a HX . It worked very well except that all the interconnecting hoses and various HX heights caused surge boiling. You can see the waste wash exiting the the end of the liebig . I could have connected the input of the liebig straight to the bottom of the re-boiler but I didn't simply because I already had it as it was . But basically the waste in the liebig acts as a fluid lock .

[Yummyrum]

So I rearranged all the whole thing . Lowered the Vapour HX so it was closer to the Bottoms HX .
Replaced the Bottoms Liebig HX for two smaller condensers in series.

You can see the waste pipe is again setting the final boiler level in the boiler and again I could have feed the bottoms HX straight from the bottom of the re-boiler and used the waste pipe height to set exit level in boiler .

Incidentally this set up worked a treat and I was able to strip a Sugar wash very well with it. There was no erratic behavior.
Basically I was stripping using 3300w @ 5.4 l/h @ 56% ABV
I am hoping to do a build topic soon as it hopefully will contain more detail of the nightmares involved in getting these bastards to work .
Then I intend to revisit Rum with this using anti-foam

[Seb]

Thanks Yummyrum. I understand that you struggled to get the wash preheated enough before entering the boiler. I had this exact same doubt for what I plan to be a 5l/hour @ azeo from wash. If I have to inject 14ml of wash per second into the boiler, it has to get there very hot. So I am planning to put a wash preheating coil directly in the furnace (cane biomass fire, mandatory), well not too directly but close enough to get the wash near boiling when pumped into the boiler. It's crazy but is there another way? There would be a continuous flow pumping in this coil: water before and after running the wash so that it never burns until the whole set cools down. I dont understand the set up of your pics, but I understand you solved this in a less crazy way. Do you think that instead of installing the coil straight in the furnace I put it in a bain marie on top of the fire, I will still get the wash preheated enough?

[Yummyrum]

Seb , the main issue with a continuous stripper is that the boiler power and the feed rate mist match each other perfectly 100% of the time .If not then the column will crash needing to be basically shut down and restarted or run with a very low output AVB .

As an example , I was running on Electricity , it was running smooth as , then suddenly , the sun went down , my neighbours huge grid feed solar array stopped feeding and my power dropped .... next thing , the column colapses and it takes me around 15 miuates to get it all stable again .

I can’t possibly see how you are going to run this with a fire under it ..... it just won’t be stable enough .
My only thoughts are if you can use your fire to run a steam generator and somehow regulate the steam so that you can feed it into the stripping column . I’d imagine you would need a bypass valve to vent the surplus steam the column wasn’t needing ..... how you would regulate it , I don’t know .

If you then have surplus steam , you could use that to pre-heat the wash through a heat exchanger .You then could adjust the steam to the pre-heater to maintain a constant feed temp .
Just thoughts

[Seb]

Yummy, I will regulate by VM, basically this one:

vapor-management-reflux-still-design-VM-300x231.png (87.1 KiB) Viewed 5950 times

More heat? More reflux. This still is meant for fuel ethanol, it has to be money efficient. I have to use cane biomass fire as it's the only thinkable way here and for money reasons I can't use a steam generator. Electricity even less. After some hours running it we should be able find the fine tune, just as they do it for cachaça. I will make the 4" packed column 3 meters high so that the worse that can happen is the collapse you are talking about by lack of energy and in case of excess of energy it should avoid low abv ethanol or at least reducing that possibiliy thanks to this height.
It comes down to inject mash at a rate of 14ml per second (or 50 litres per hour, 8 hours a day) and make sure it all boils and to handle that so that we collect ethanol at the other end. To achieve this constant boiling we will feed the fire continuously.
Do you think the wash preheating coil put in a pan of boiling water is enough? It is certainly much safer than direct contact with fire, but is it efficent? The coil is 20 metres of 3/8.

[cayars]

Something like this is in my plans for spring about 6 to 7 months out.

I was wondering about 2 possible easy ways to heat the mash. Would it be possible to put a worm directly inside the boiler that you pump fresh mash through on the way to the top of the column. Or perhaps a coil soldered to the outside of the keg to transfer heat from the keg itself? You would loose heat on the copper tubing coming out of the boiler going to the top of the tower but it would still be very warm.

So basically a wort chiller type thing used for heating vs cooling but using the heat energy already inside the boiler. Seems like this could be easier than trying to harness condenser or boiler exit water to pre-heat with. If it got to hot it should be easy to knock the temp down.

Thoughts?

[Yummyrum]

To answer Seb and cayars .
You need the wash going into a continuous stripper to be close to 80°C ... a little higher is even better .
You basically need it almost but not quite boiling . It needs to be this critical temp so that when it hits the packing ( which is also close to this temp.... well its a bit hotter ) it will instantly phase change on contact keeping the equilibrium constant in the packing .

When running wash through a heat exchanger that on one side has wash at around 20°C and boiling water at 100°C on the other , the best you can expect to raise the temp of the wash is around 50-60°C . It is way short of the mark.
Sure you can inject wash at lower temps but you have to reduce the feed rate significantly so that the up rising steam from the boiler has enough energy to maintain column equilibrium as well as still provide energy to cause the initial phase change on contact with the packing top .... but.... the amount of alcohol released verses the upcoming steam is so low that the strip has a really low AVB ..... read about 20% verses 55% ... IE ... its not efficient at all . .

The real heat available is from the condensing vapour . It's hard to believe but there is almost enough heat transfered from the condensing stripped vapour to rase the incoming wash up to about 70°C

So all thats needed is to raise it another 10°and its ready for injection . .

So your thinking , well if its close to 80°C already and and you can just feed it at a reduced rate , surely thats close enough .

Well sadly no . See now you have reduced the feed rate . There is no longer quite so much alc vapour going through the Vapour heat exchanger .... so there is less heat energy being transferred to the incoming wash .
You get a chasing your tail effect and before you know it , your feed temp is spiralling down to a column crash .

This is where that extra 10°C of wash heating gets you to the happy place .
Now if you run that 70°C from your vapour heat exchanger through your boiler or bottoms heat exchanger , you now have 70°C on one side of it and 100°C on the other and the output is now around 80-83°C .... bloody perfect .

So the reality is that one form of wash pre-heating on its own is not sufficient to maintain stable condition and a combination of both vapour heat gain and waste heat must be used .

So basically a wort chiller type thing used for heating vs cooling but using the heat energy already inside the boiler. Seems like this could be easier than trying to harness condenser or boiler exit water to pre-heat with. If it got to hot it should be easy to knock the temp down.

Cayars , I wondered about this too . It would be tricky to het the length of the coil right to match the wash flow through it . I think it would be easily possible to get the wash boiling which as you say could be mixed with cold wash to temper back to ideal temp .

What concerns me though is that the boiling wash will be under some pressure due to it being in a predominantly gaseous state as its behind a mixing valve .
Is an interesting idea that I’m sure could work but it sure would take a lot of trial and error to get the coil right .

[The Baker]

Something like this is in my plans for spring about 6 to 7 months out.

I was wondering about 2 possible easy ways to heat the mash. Would it be possible to put a worm directly inside the boiler that you pump fresh mash through on the way to the top of the column. Or perhaps a coil soldered to the outside of the keg to transfer heat from the keg itself? You would loose heat on the copper tubing coming out of the boiler going to the top of the tower but it would still be very warm.

So basically a wort chiller type thing used for heating vs cooling but using the heat energy already inside the boiler. Seems like this could be easier than trying to harness condenser or boiler exit water to pre-heat with. If it got to hot it should be easy to knock the temp down.

Thoughts?

Look up on the web, Armagnac Still.
and find a diagram.

Geoff