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Another StillDragon Continuous Design

I know there's a few SD customers operating and designing continuous systems here in Australia/New Zealand and overseas, and here is one that was shown to me by one of my customers.

A few stillers came together to develop and implement this for stripping wine feedstock. I'll let one of them explain;

After a few melt downs and trialling of jet sizes we got it going as a continuous stripper, returning between 75 and 89% ABV from wine. You'll see the alcometer in the parrot of the attached picture. There is so much flavour in the spirit that it will make a fantastic brandy. The rig in the picture could process 40 litres of wine per hour, by increasing the power in the pot to 7.2 KW and 3.6 KW in the RIMS tube we should be able to do a bit over 70 LPH. The next part is to do a complete distillation by taking off the ethanol and the flavour components off part of the way up the column with feints out the top.

This weekend I'll be trialling the Continuous still with Ethanol out option. The number of bubble plates may be altered depending on just how hard we can drive it.

Yep, 70 L/h!

I'm hoping for some video or some better pictures of the unit in operation and will keep the members here updated where i can.

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Continuous still after 1st trial.jpg
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Continuous Still with Ethanol Out.jpg
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  • More please.

    StillDragon North America - Your StillDragon® Distributor for North America

  • I hope to get more.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • How is the feed stock speed regulated?

    StillDragon North America - Your StillDragon® Distributor for North America

  • Does the RIMS setup run like a primary boiler or only a liquid pre-heater?

  • edited July 2015

    He mentioned by sizing the jets correctly. What i have posted above is pretty much all the info i have at this stage. hopefully one of the guys will chip in and explain a little more.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • edited July 2015

    Just finished another weekend adding to the development of the continuous still. Getting my head around the balancing act of temperatures to get the highest ABV coming out Murphy struck as I went to make a cuppa. The jet was blocked by something and the flow stopped, the pressure relief valve on the RIMS was still set a little too high so the wine inside went to steam and it got hot enough to melt the solder, blowing off the valve and pumping a stream of wine out. Fortunately this saved the element from burning out.

    Over the weekend several things became obvious.

    1. Have an over temp alarm on the RIMS tube that cuts power to the element.
    2. Recover the heat from the spent wash. Preheated wash gives a more stable operation of the RIMS tube as the controller doesn't need to cover such a wide range.
    3. Use a fuzzy logic controller as these learn when to turn on and off the element so there is less hunting done by the controller to home in on the set temperature.
    4. Have temperature sensors in the pot, RIMS tube, injection point, at above in the column and after the reflux condensor.
    5. Insulate the column as the operation can be upset by varying reflux caused by winds.
    6. Mount the RIMS tube on an angle so that you can replace an element without having to break apart the column.
    7. Mount the jet on a 2 inch endcap that clamps to a ferrule on the side of the injection module so that jets can be easily changed or inspected.

    It became obvious that getting the stripping operation perfected first before going to pulling off clean ethanol was the way to go. There are so many variables you don't want to jump in too far.

    For stripping it was best to have the pot around 94C, the output of the RIMS at 95C and above the reflux condensor around 79-81C.
    We were about 300 metres above sea level, so you'll need to adjust for that.
    If the pot goes over 94 there is too much water in the vapour going up so ABV drops.
    At 95 or more out of the RIMS the alcohol flashes to vapour immediately on leaving the jet, giving a higher ABV as the heat in the column doesn't drop as much.
    The picture is of the continuous stripper delivering around 82% ABV.

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  • So what is your bottoms ABV at 94°? It seems quite low. By my calcs that's over 7% and your feed temp is higher??
    I don't understand. Pot is the boiler/steam generater and RIMS is the injection preheat?

    Could you add a few more rectification plates between the injection point and deph to get your take off ABV back up again?

    When I heard about changing the injector size to control flow rate I thought "Cool. Simple and easy, but what if it blocks?"
    I figured on wine it was fine, guess not. Maybe an inline filter.
    Does the injector have to 'spray' for it to work?

  • Hi jacksonbrowne, The waste wash is about 0.2%. We tested this with some lab gear. We boiled water in the unit and found that the boiling point of water was 97C (1000 ft altitude and whatever the barometric pressure was at the time. We rinsed it out and then boiled the waste wash. After calculating the difference it worked out to near 0.2%. BTW, the wine is around 14% ABV. The ABV in the pot will vary depending on how much wine condenses and falls back to the pot, how fine the atomisation of the jet is, the temperature of the wine at the jet and how much reflux there is on the reflux condensor.

    The pot is the vapour generator, any wash that falls back to the pot boils off again. The RIMS tube preheats the wine. This week I'll be rigging up a heat exchanger to extract heat from the waste wash to preheat the wine.

    We have an inline filter but there are components in the wine that can build up on hot surfaces and then be released. I haven't examined the jet yet as it's a long drive back home and I'm now at work. It will be interesting to find out what blocked it. We plan to use a cyclonic filter for the next run and have a flow meter on the wine line with an automatic shutdown if the flow stops.

    The finer the atomisation of the spray is, if everything else is right, gives a higher ABV as the alcohol component of the wine flashes to vapour immediately after leaving the jet.

  • @ElectricEd said: For stripping it was best to have the pot around 94C

    is the bit I didn't get. It's still 3° under your water boiling point which I would guess is over 4%.
    If the pot is boiling at 94° and the over flow is going to drain... Typo or am I misunderstanding?

    Sounds a bit like a spray dryer. What's your background?
    If you're already adding a flow meter why not use the feed back on a control valve to look after the flow rate?
    Have you considered multiple nozzles? So if one blocks you've got a few more to keep the flow going.
    Interesting stuff. I did a heap of regen stuff on HD using SD 2" shotguns as heat exchangers.

  • The pot is boiling off the alcohol that falls into it, not the water. If the water is hot enough to be boiling, then the steam going up lowers the ABV of the product. My backgound is in electronics and control systems. I suppose it is a bit like a spray dryer. The water component in the pot is made up from the parts of the wine that don't go over the top. It's purpose is to return any of the lighter components as a vapour to the column. When the whole rig is running properly there is hardly any alcohol getting to the pot. One reason for the temperature difference could be the position of the sensor which is at the drain point. I'll have to check that. The double nozzle idea is good, I'll look for some finer jets. It means that an alarm will have to be raise if the flow drops to half.

  • edited July 2015

    Im intrigued by the jet concept. Is the pre-heater boiling or superheating the wash and then pushing vapor through the jet/injector? Or is it simply preheating and using the pump pressure to "spray" the wash in? Not understanding how your rims temp could be 95c with a 14% wash, without superheating under pressure.

    I'm asking because the design as posted should actually be less efficient than your numbers suggest, so if you are getting good numbers out of it, there has got to be a wildcard in this mix that's doing it. From what I can see, it's got to be the jet/spray/injection approach.

    Your injection point at the bottom of the plate stack runs somewhat counter to the accepted approach for a stripping column, which is what I think would cause this to be less efficient.

    So if you are getting less than quarter of a percent in your waste stream, gotta figure out what's making the magic.

  • edited July 2015

    The RIMS tube heats the wine to 95C and then goes to the jet. Because the jet points upward you can see it from the plateless bubble tee window above. When it's at 95C the cone spray nearly disappears around its periphery. The watery components of the wine then appear running down the sides of the column and in the window. Above the marbles below there is a stainless lid from a Fowlers Vacola jar that fits nicely into the column. It has 9 holes in it to spread the descending liquids over the hot marbles, providing another place for the alcohols to vaporise and rise up again. Its interesting that real world trials coming from a wildcard approach differ from theoretical prognostications.
    It doesn't seem strange to me, if you are injecting a 14% ABV wash at 95C into a hot column it seems obvious that the alcohol has to suddenly vaporise and go upward. Any alcohol that falls down will be reheated either by the marbles or by the liquid in the pot, it will vaporise and go upward.
    The tricky balancing act is to get the temperatures right at the different places in the column and pot.

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  • edited July 2015

    With very careful balancing of the temperatures, this is the best that I could get...

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  • Tough to see in that picture, even zoomed. Is the nozzle spraying liquid or wet vapor?

  • I took a heap of pictures from all angles and that's the best one. I need a light inside the bubble tee and a polarising filter. The jet is spraying wine at around 95C, the alcohol is turning to vapour around the periphery of the spray cone, the cone looses visibility at this point and you can see liquid running down the walls of the column and around the window.

  • edited December 2015

    We visited a distillery in Northern Victoria that belongs to a fellow we met a few weeks ago. Among other things he has a 3 column continuous still that can produce 1000 litres of 96% grape spirit per hour. It uses steam injection from the bottom of each column with the wine being introduced from a bit over halfway up the first column. The superheated steam flashes the descending wine alcohols to vapour which continues into the second column. Fusel oils are removed in the first few plates in the second column, ethanol is taken off about halfway up the third column with methanol taken near the top.
    It's made me re-think my design. Steam injection gets around the problem of blocked jets.

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    Now that's a still 2.jpg
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  • Struth! Those columns are massive!

  • It always impresses me to know how they keep those beasts fed.

    Can you imagine the fermentation capacity to run those columns? And the amount of fermentation material coming in the front door? I would imagine you would require a few semi loads every single day to make efficient use of that equipment.

  • edited January 2016

    The concrete wall to the left is the end of 8 (if I remember correctly) 130,000 litre tanks to hold the spirit. There are more underground tanks to hold the wine with a total of around 1.4 million litres. They take excess wine from the wineries in bulk tankers. I went to the top of one of the spirit tanks and had a man-hole opened. The spirit was about 400 mm from the top and was the cleanest smelling and smoothest tasting grape spirit I've ever tried.
    This is the third column where the spirit is taken off and the heads and fore-shots come out the top.

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  • Goes into the local fortifieds?

  • Yes. It used to be owned by McWilliams, they used it to fortify their ports and sherries.

  • :D my wife was drinking that last night.
    Didn't get the name off the column maker did you?

  • No, but I'll ask the owner if he knows. I've left his business card at home so I'll have to get back to you on that one.

  • @electriced did Dawid tell you the story of how they used to run marathons keeping the columns balanced during the runs? Amazing stuff.

  • Hi yurgle, yes every 15 minutes to keep it in balance. So you know Dawid too? Were you at the fed uni course?

  • i met him through my day job in commercial bulk spirits and I was on the 5 day course at starward about a year ago with frank Vriesekoop - is that the one?

  • I did the 2015 course in December and met Frank Vriesekoop too. A great bloke and Peter Aldred is also.

  • Was it at starward again? Frigging freezing when I was there! Yes they are both great guys

  • Yes, at Starward (New World Distillery) at Essendon Airport. Very sensible of them because Essendon Airport is federal land so they don't get hammered with state laws. :)

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