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Flooding Packed Section

Hey guys wondering if running a perf plate at each end of my packed section is causing issues as I'm not getting much bubble action on my top plate

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  • The filter discs are known to have some flooding issues at higher reflux ratios. Perf plates should be ok?

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

  • what are you using in your packed section ?and is it tightly packed or loose ?

  • Tightly packed ss scrubbies was using perf plates but it flooded by top section

    Now using old cap plates without caps and have flooded the top again this new rc is awsome haha

  • Also flooded my procap plates 4800 have dropped back to 2400w for now

  • Could be flooding from the bottom up.
    Were the plates correctly sized? Do they have down comers?
    Do you have sight glasses installed to see top and bottom?

    @Clickeral said: I'm not getting much bubble action on my top plate.

    Does that mean flooding? Sounds more like a bad plate design.
    You could probably give more info

  • Ill do a proper writeup tonight

  • You'll be the first to flood Procaps. I tried with a tap running over them and couldn't do it.

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

  • Think it was because I foooded the packed section so the vapour had nowhere to go

  • Same thing happened to me a couple of weeks ago. Was my first go with a packed section. I had it over procap 4" plates on 3600w. Felt like the packed section was filling with liquid that wasn't dropping through the screen below the packed section to the next plate. Then it all seemed to drop from the packed section at once and flooded the tee's. I freaked the first time and killed the power and let the column drain.

    Flooded again a couple of times as I was trying different temps and RC flows. Gave up and put it on the too hard basket. My thoughts were to try a spacer between the top of the packed section and the RC and also to try a wider mesh on the bottom of the packed section.

    I am currently just running neutral on plates alone until I get some time to understand it a bit more.

  • @yurgle said: Same thing happened to me a couple of weeks ago. Was my first go with a packed section. I had it over procap 4" plates on 3600w. Felt like the packed section was filling with liquid that wasn't dropping through the screen below the packed section to the next plate. Then it all seemed to drop from the packed section at once and flooded the tee's. I freaked the first time and killed the power and let the column drain.

    Flooded again a couple of times as I was trying different temps and RC flows. Gave up and put it on the too hard basket. My thoughts were to try a spacer between the top of the packed section and the RC and also to try a wider mesh on the bottom of the packed section.

    I am currently just running neutral on plates alone until I get some time to understand it a bit more.

    Tried the spacer between the rc and the packed section it just filled up with distillate :(

    I was orginally running two perf plates each end of the packing and that flooded

    Seems the packed section just won't drain fast enough with 4800w going through it and full reflux on the SUPER RC

    The normal RC the output just comes out

    Will have to have a rethink how i run my vodka runs or get my power controller going

    2400w isn't enough to keep 6plates and the packed setion going

  • edited March 2016

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    I put a sight glass in under the RC to see if it flooded

    The colour is from one of the copper plates, this was at the end of my run

    I had another sg at the bottom of the packed section and it didn't seem to drain very well

    When I first packed it drained no issue so may need to repack to allow some drainage

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  • Put up a photo of your packing and also, more importantly your packing retainer.
    Show us one of your perf plates too.

  • edited March 2016

    Here's mine. 500mm packed with s/steel pads

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  • Im only new to this and had a problem on my last run and brought it down to an over packed,packed section. Every time I finish a run I pull out the s/s packaging and rinse with warm water.i have only ever used 11 scrubbers in a 510mm 2" and was loosely packed but on my last run I jammed in 16 s/s scrubbers and I had my top plate on my baby crystal dragon flood and now matter what i did,lower power, raise power, it wouldn't change. So I turned it off and removed the scrubbers and repackaged it loosely back to 11 and fired it back up and it was back to normal and it ran fine. It might have nothing to do with what your problem.

  • The filter discs can cause the issue at higher power levels. Some people have made a retainer of 1/2" stainless mesh and that solves the issue.

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

  • There's your problem.
    A perf plate should also have some way to drain like a down comer.

  • edited March 2016

    If you do a search on aliexpress for "tri-clamp filter", you'll find an excellent tri-clamp filter plate. I bought one, works a treat... little bit expensive but makes reconfiguring a hybrid column much easier.

    May be @punkin could look into stocking a few if he can source them?

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  • Even that would be too much restriction for me.
    If you actually do the testing you'll see how little it takes to cause a bottom up flood when you push the column.
    I have custom laser cut ones made up that are a bit more like a spider web. Very open but still OK for SPP.

  • @jacksonbrown hey mate what size holes did you put in yours. I run a laser cutter and made mine out of 0.55mm 316 stainless with 4 mm holes.

  • I'll see if I can find the cam file.
    The SSP I was trialling was 4.5 mm I think so nothing bigger than that.
    I looks like a New York sewer cap.
    I've don't like that SSP stuff anymore. So a simple cross in a disk would do it.
    I also have some reflux directing discs that work well and do the same thing with rolled packing.

  • Remember the packed section will be what sets max power for the column. No matter what packing I used I ended up with a simple wire grid that was just enough to hold up 1 stainless scrubber and that scrubber held up the rest of the packing.

    I never took the packing out to clean it, just flushed it through in situ.

  • I find that the scrubbies hold themselves in the 4" section - no need for a plate

  • I just run an empty bubble plate on my 1500mm packed 4" section took almost 6 kW to flood the plate below it. It holds 80-90 SS scribbles.

  • edited March 2016

    @crozdog said: I find that the scrubbies hold themselves in the 4" section - no need for a plate

    Mine hold until I push that last one in

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    Cleaning copper residue is a PITA

    Might have to run less water through the Super RC next run and try to prevent flooding

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  • edited March 2016

    @Johnboy said: I just run an empty bubble plate on my 1500mm packed 4" section took almost 6 kW to flood the plate below it. It holds 80-90 SS scribbles.

    I only run one plate under my packed section just so I can see what's happening it works out to 18 plates. Could the pressure imbalance between packed and plated section be creating a lock preventing the liquid from dropping or is that not an issue?

  • You don't need the bubble plate on top of packed section

  • edited March 2016

    I agree with @jacksonbrown. The perforated plate should have a dedicated downcomer area. This larger area will reduce the vapour velocity moving upwards, which will entrain less liquid and allow the reflux to move down the column.

  • @Anro said: I agree with jacksonbrown. The perforated plate should have a dedicated downcomer area. This larger area will reduce the vapour velocity moving upwards, which will entrain less liquid and allow the reflux to move down the column.

    Tried that and it flooded worse then with the setup in the pics below

    Seems I will have to have another go next time with just the RC ontop of the packed section

  • Flooding occurs when your upflow velocity is too big and then the vapour entrains the liquid that tries to flow down the column. If the downcomer is not the issue, maybe your packing density it too high. By introducing a packing into a column, one reduces the space available for the vapour to flow upwards. The liquid that is also present in this space reduces the available space even more, which increases the vapour flow again. I think Jez commented on how the number of packing material affect the performance of the baby crystal dragon. Maybe try and reduce your packing material, i.e. packing it looser.

  • @jacksonbrown

    Hey mate what do you mean by reflux directing disc's ? Do you have a pic?

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