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Internal Plate Bypassing

Anyone familiar with the mechanisms of these? (Examples being any of the German stills) I've played around with the external ones, they mostly work and mostly look like total garbage too. I understand what is essentially happening (openin/closing some sort of opening on or near the plate) but haven't gotten a chance to play around and investigate.

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  • Like the old Time-Life commercials used to say - "It's in the book!"

    here is a pic:

    image

  • Yep found those on the net before, was seein if anyone had any extra insight or is it really all that simple... Which seems to be the case. I'm actually slightly more interested in the gaskets used now. I know the levers move with much ease

  • Harry had posted a heap of ideas over on Artisan a while back. It'd be worth your look from memory

  • It's that simple, any way you drain the liquid off the plate will work just as well as any other.

  • I can definitely attest to those side draining mechanisms being rather terrible. Experienced plate flooding and uneven levels in the other plates. But that column was horrible in general. I definitely want something draining off the actual plate. Building the mechanism above probably wouldn't be awfully hard, it's more figuring out a good way to stop vapor leaking

    @crozdog any chance you remember the thread? I haven't been on that forum too much

  • It varies dependent on perforated plates or bubble cap plates.

    With perforated plates if you provide a reasonable size vapour bypass the plate just dumps its contents. That can be done with an external bypass.

    With Bubble cap plates you need to remove enough of the liquid to break the plate seal. On some they just lift a single cap off the plate and that seems to do the trick.

  • edited October 2015

    I could imagine a few ways to come up with a creative seal that doesn't include the need for a gasket.

    Tapered joint and plug, where the plug is a solid piece of copper. But this really risks seizing which wouldn't be a good time.

    Flat circular section with a good amount of metal overlap to a hole below, the circular plate should probably be weighted to ensure sealing, but I think the liquid weight alone would lock the seal to the plate. Of course you would need to ensure a superior level of flatness on both surfaces.

    You don't even need to limit yourself to "up and down", which seems like the most common approach. I could imagine a number of different ways you could make a slide work just as well, where you open the bypass by simply pulling out a rod, or pushing it back in. In this model you could utilize a nice compression fitting as your vapor seal. Unlock, pull out, relock, done. Seems so much easier than dealing with the number of mechanical connections, linkages, etc you need with a rotating mechanism.

    The only gasket material I'd use in a column would be teflon, and that isn't soft enough to provide any realistic benefit over a metal to metal surface.

    Realistically, a small amount of weep isn't a problem, which is why some of these mechanisms look downright crude.

  • I still think magnetic would be the go. Little, strong, teflon coated magnets could be employed in a variety of up/down or in/out ways.

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  • It doesn't really need to seal, does it? Slight weeping is inconsequential when the down comer is streaming anyway. The pressure from the plate underneath will help out too. Bubbles are more likely.

    What is the benefit to taking out plates anyway? Can't we achieve similar results by cutting the flow the dephl right back?

  • I should have specified leaking from the side of the column where the lever meets the column wall. That makes the magnet idea pretty intriguing

    It gives one the ability to fine tune characteristics of the product coming out. A single plate can make a lot of difference so you can imagine what several can do. The still I'm designing is currently 8 plate (12" so I'm not pulling things apart) so what if I only want to run to 2-4 for a whiskey or rum? Having the ability to turn plates on and off is great for R&D, I'll add as many tools as I can to the toolbox.

  • edited October 2015

    @Kill_Devil_Spirit_Co said: crozdog any chance you remember the thread? I haven't been on that forum too much

    It took a bit of digging but here is the thread, what you want is about half way in through to the end.

  • more exact link...

    Now, you could just enlarge one bubble cap hole (might need to tighten the bubble cap down on a washer or something for it to function correctly and be the right height)..

    However a better idea I would say is that if you swaged or formed or dimpled or whatever the bubble plate so that it was somewhat like a funnel, it would drain the plate quickly and completely when lifted, and allow the cap to sit at exactly the same height as the other caps.

  • edited October 2015

    I liked my idea about using lengths of interconnected chain and only dealing with a single penetration from above. The connection between drains is by small sections of chain, with the length of chain between each plate incrementally getting shorter from top to bottom.

    By pulling the chain/lever upwards, you will disable a single plate at a time, starting from the top plate, going downwards, one by one. If you maintain equal spacing, you'll simply disable all plates at once with a small upward pull.

    The only requirement is that the chain path is aligned up and down, and you have enough play to account for all plates (plate spacing at top plates is probably the issue).

    The chain difference from plate to plate really only needs to be 1/8-1/4" or so to be effective, so 8 plates requires 1-2 inches of upward pull to disable all plates. Use something like a small stainless rod and compression fitting with teflon ferrule. Loosen, adjust, tighten.

    You can use something as simple as stainless ball chain (think dogtags). Assembly could be very easy. You would need to connect each plate from bottom to top as you assemble the column. The chain would very easily pass through the dephlegmator tubing as well.

    The real problem with this approach is potential misalignment if you get angry with the chain and the stoppers flop around like wind chimes. Also, you'd need to weight the drains to provide some sort of positive pressure to seal better.

    I don't know, the system runs vertical, therefore it seems more elegant to me to look for a vertical solution, rather than requiring so many horizontal appendages to solve. The alignment necessary between the plate, the drain, the lever, and the wall needs to be very precise, unless you use a sloppy linkage.

  • It would also solve for both the crystal dragon and the stainless tee plates...

  • I found this somewhere through all the digging on the artisan forum. Man do people get bitter easily over there. Anyway...

    image

    image.jpg
    685 x 267 - 13K
  • edited October 2015

    Surprised those fancy Germans came up with such a crude mechanism? Single o-ring seal? That o-ring is a wear item and needs frequent inspection, and the torque on that stem needs to be precise. You know, death and all.

    First I heard some information about V-somebody that made me do a doubletake, and now the fancy Germans are shown to be pretty pedestrian. I would have imagined sealed Bearings, shaft seals and wipers.

    Whats this world coming to. Next somebody is going to tell us that one big bubble cap is magic!

  • @grim said:

    First I heard some information about V-somebody that made me do a doubletake, and now the fancy Germans are shown to be pretty pedestrian. I would have imagined sealed Bearings, shaft seals and wipers.

    That's what had me. Was expecting the utmost most intricacy and got this in return haha. At the same time, is it really much different than the seals between the agitator shafts and the boiler ceiling? Those still irk me a little too.

  • did you see Rednose's and harry's ideas on page 3?

  • Yeah I went through everything, thank you again for finding all that. Lots to ponder now

  • There’s actually a bit more going on with that o-ring design than first meets the eye.
    Gland design can get pretty complicated but this is only a low pressure app.
    I went through all that stuff designing a hydraulic sausage pump a few years back.
    I can’t seem to find the document that I was using back then but there are a few good ones around.
    If it’s designed right that system will work fine. Tension is not an issue as it’s provided by the o-ring itself. That threaded piece is tightened to metal on metal.
    The o-ring just fills the void that is left.
    The trick is to get the right size o-ring in the right material and match it to the correct groove.

    What's the problem with external valves?

  • edited October 2015

    @jacksonbrown said:
    What is the benefit to taking out plates anyway? Can't we achieve similar results by cutting the flow the dephl right back?

    Main reasons.
    1. By pass a plate that is fouled or blocked
    2. Run a different product on the same column on consecutive runs without physically removing plates
    3. Run different products on the same column during different parts of the SAME RUN.

    You can in principle produce any product on a column at the appropriate reflux ratios, but speed and quality is variable. Your quality may be easier to control by reducing the plate count and increasing the reflux ratio.

    So yes you can adjust the dephlegmator flow, but it does have knock on consequences. It is sometimes more convenient to adjust the plate number.

  • I had horrible experiences with plate flooding and unven plate levels when using the external valves. Then again that still sucked (and still does to this day). And to be superficial, in my opinion, they're ugly as f...

  • Sounds like a lot of this distilling stuff runs into the same issues.
    A sound concept gets written of due to shit house execution.
    Personally I'm exploring the reflux control idea a lot more but if you really want to disable specific plates what about using correctly sized, horizontal dump valves, designed with minimum dead leg and perhaps positioned at the back of the column so there not as visible?? If I really couldn't handle valves then I would probably look at perf plates and change the downcomer design to just a single tube that can be dropped so that it is level with the plate surface.

  • The problem is there is a kind of positive feedback thing going on with plates and passive feedback. They form a lower bound on the ABV you can get out. You'd imagine with zero active reflux, you'd be able to get down near pot levels, but something is going on with the plate liquid (perhaps upward moving vapor actually enriching the liquid on the plate as it passes through).

    Hence the approaches to either use a drain to remove the liquid, or give the vapor some lower resistance path to follow.

  • I just don't think we have good enough control over reflux the way things are done at the moment.
    My column looses a couple hundred watts just to passive reflux. You don't see many craft guys insulating their columns though.

  • edited October 2015

    @jacksonbrown said: If I really couldn't handle valves then I would probably look at perf plates and change the downcomer design to just a single tube that can be dropped so that it is level with the plate surface.

    if you are penetrating the column to adjust the height of the downcommer you might as well disable the plate. Unless you actually want to be able to change the depth of the liquid on the plates.

    Disabling perforated plates is really easy. You just need a vapour by pass to equalise the pressure on both sides of the plate and the plate will promptly dump its contents. That is easiest to do with a simple external valve hidden behind the column.

  • @jacksonbrown said: I just don't think we have good enough control over reflux the way things are done at the moment.
    My column looses a couple hundred watts just to passive reflux. You don't see many craft guys insulating their columns though.

    glass columns have far better insulation than the Stainless Tee versions, my dash loaded the plates with reflux from the bottom up, and the CD loads from the top down... now it could be the heat capacity of the stainless contributing at teh beginning, but there is definitely more heat conducted away from a stainless still body..

  • edited October 2015

    You ain't kidding. The other day I was playing with water, just for kicks (the bain marie discussion), and was boiling water in water, but the using pyrex lab glassware as the inner vessel. I couldn't get the inner vessel to boil, zip, nothing. I was tempted to dump a bottle of bad gift wine and try that, but it was clear there were better ways to use my evening.

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