Dry bottom plate

[blond.chap]

Just a quick question for the bubbler runners, do any of you have a bottom plate which loads correctly?

I've noticed on all of my runs the bottom plate stays dry through the entire run, even if I do manage to get some liquid up to the downcomer height, the vapour still bypasses through the downcomer and spits the liquid out of the way. I figured it was a quirk of my build, but watching ByB's still on Saturday, his bottom plate stays pretty much dry as well.

My only explanation (pure theory), is that at the bottom plate there is about 60% ethanol, 40% water, while above that there is more like 10% water, so the flow rate on the bottom plate is higher, meaning that vapour speed is higher, so the vapour is overcoming the liquid lock and spitting it out. I'm guessing that an inline thumper would helps with this, my other thought was putting a plate below the bottom one with some larger holes might provide a condensation surface and reduce the flow rate.

Does anyone else have a suggestion on what might be going on and/or how to resolve it?

For the record:
- 4" columns on both
- My bubbler uses 3/4" downcomers in 1" caps
- ByB's has 3/4" J-types;
- No significant differences between plates in either
- I run on 2.4kW, ByB has 2.4 to 4.8 and even on full it didn't load

[Linno]

Hey B.C

Have you tried running it less than 2.4 to see if you can slow the vapour down enough to load the bottom plate properly.

[SBB]

Never had the problem, my bottom plate only goes dry at the very end of a run.

[bt1]

Howdy,

if I over power the still it gets flaky, dries, refills dries etc.

Can play around with his to check by varying heat.

bt1

[Sam.]

You running perf plates?

My FSD single cap design has no problem at all

[Yummyrum]

Sorry Blondie, not in th bubbler club yet but thought worth mentioning that Old Dog and Kentucky shiner had issues with ddry bottom plates when OD made the first perfplate bubbler.
After much time it was discovered that wall to plate gap was too much and vapour was bypassing the holes .
Tighter plates fixed as did soldering in the first plate

[blond.chap]

Thanks for the replies everyone.

Yep we both run perforated plates. Starting slow to get the liquid level up sounds pretty plausible, I've been restricted by not having a controller (to be resolved soon), but that's definitely worth trying. I'll bug ByB to try and see if all of his plates load.

You running perf plates?

My FSD single cap design has no problem at all

Is that a touch of smugness I detect? Don't worry, I'm already jealous.

Cheers for the input Yummy, my plates are soldered in, so there's a full seal.

[BackyardBrewer]

We can always try your still on my boiler with dual controllers and vice versa to see how we go as a test but with my bottom plate I get the weakest load. I think of my column as a pyramid upside down. It goes from great on the top to OK on the second and third, meh on the fourth and pretty flat on the bottom.

No run for probably two weeks so I'm going to do some adjustments in the mean time on levels of the plates and and see if that makes a difference. I think cups on the down comers is in my future too.

[blond.chap]

Yep, I'll take you up on that.

Any reason you're thinking of cups now? I've just converted all of my cups into Js, mainly because my shoddy cup construction was flooding the column.

btw, you should probably update your avatar, its upside down...

[Aussiedownunder01]

Yep, I'll take you up on that.

Any reason you're thinking of cups now? I've just converted all of my cups into Js, mainly because my shoddy cup construction was flooding the column.

btw, you should probably update your avatar, its upside down...

Don't suppose you have a photo of the new jss

[blond.chap]

There are some pics on the latest post here:
http://www.aussiedistiller.com.au/viewtopic.php?f=36&t=3751

Mid construction at the moment, so haven't run with them yet.

[Sam.]

Is that a touch of smugness I detect? Don't worry, I'm already jealous.

Cheers for the input Yummy, my plates are soldered in, so there's a full seal.

:laughing-rolling: Wasnt try to but oh well :D

What if you built a bubble cap for the bottom plate? :handgestures-thumbupleft:

How big is the wall gap in yours BC?

[blond.chap]

Not a bad idea, if the power adjustment thing doesn't work I'll try that.

My plates are slightly wider than the inner pipe, before I soldered them there was a constant leak from the triclamps.

[bluess57]

Yep I have the "problem".
BTW, my bottom plate is soldered in, all others are removable.
I've got a bubble cap plate I can put in below my column and I've still had the problem on the bottom plate in the column.
I attribute it to column being off vertical as I run on gas outside on pavers and sometime the vertical setup has been off.

Also last run I washed the column with water to pre-fill the J trap and got loading on the plate.

[deejay]

yep had the same problem then i built a controller and problem solved :handgestures-thumbupleft: cheers

[Linno]

yep had the same problem then i built a controller and problem solved :handgestures-thumbupleft: cheers

i have caps and havent had this issue with any plates but i have seen the spittin that blonde was refering to and it was as a result of too much power. the cap had very little action but the vapour coming up the downcomer was spitting the liquid out of the way as described. also can you have a cup on the bottom perf plate instead of a j trap??

[blond.chap]

I had cups on each plate initially and didn't have any joy.

Sounds like the first thing to try is to muck around with the power so the liquid locks all fill, then set to operating power for the run. Failing that I'll put a bubble cap in as the bottom plate.

Thanks for all the help everyone, I appreciate the input