Using a bubble plate with only internal reflux

[ThomasBrewer]

I have a modular still that can be configured as a pot still, or a CM reflux still with a few plates. In pot still mode and with a single plate installed, there's a bit of internal reflux, enough to fill a bubble plate as the column gets up to temperature. Shortly into the run, without a reflux condenser to bring much ethanol down, the contents of liquid on the plate should basically be water. Am I doing myself any favors by keeping the plate in the column as a sort of "thumper" when doing a pot still spirit run, or am I likely to smear tails into my hearts for the whole run (or some other issue I haven't contemplated)?

Thanks for any pointers.

[LWTCS]

With a single plate the liquid bed will not be "mostly water".
With a single plate and no reflux condenser you're not going to drag tails up prematurely (relative to the ABV boost).

None of it matters. Run your rig every which a way you can so that you'll understand how your outfit behaves.

[acfixer69]

No to your question on the temporary plate fill. Yes you are not likely to smear you will until it dries and it becomes a pot still again.

[ThomasBrewer]

With a single plate the liquid bed will not be "mostly water".
With a single plate and no reflux condenser you're not going to drag tails up prematurely (relative to the ABV boost).

None of it matters. Run your rig every which a way you can so that you'll understand how your outfit behaves.

Thanks. My thought process was that the liquid bed would consist mostly of higher boiling point mixtures since that's all it's really being being fed without a reflux condenser.

I went a little too deep into the tails with my 9% UJSM stripping runs and came out with 6 gal of only 30%. I was hoping for a bit of an ABV boost akin to using a thumper so I didn't need two cases of jars for making cuts.

[ThomasBrewer]

No to your question on the temporary plate fill. Yes you are not likely to smear you will until it dries and it becomes a pot still again.

I'm thinking it will never really dry out though, right? Not until the feed from the boiler reaches the BP of water, and then you're [past] done anyway?

[acfixer69]

If nothing is refluxing liquid back it all goes up as vapor.

[Oatmeal]

I went a little too deep into the tails with my 9% UJSM stripping runs and came out with 6 gal of only 30%. I was hoping for a bit of an ABV boost akin to using a thumper so I didn't need two cases of jars for making cuts.

? 30% is pretty good on stripping if yer looking for flavor on a spirit run?

[ThomasBrewer]

I went a little too deep into the tails with my 9% UJSM stripping runs and came out with 6 gal of only 30%. I was hoping for a bit of an ABV boost akin to using a thumper so I didn't need two cases of jars for making cuts.

? 30% is pretty good on stripping if yer looking for flavor on a spirit run?

I definitely am looking for flavor, so I guess that was a happy accident. I've seen a lot of folks boast running a 40-45% strip into the boiler.

[Yummyrum]

. I've seen a lot of folks boast running a 40-45% strip into the boiler.

Won’t get any thumps up around here for doing that

We don’t recommend anything above 40% for safety reasons and preferably closer to 30% abv

[LWTCS]

With only a single plate and no forced reflux I'll behave very much like a pot still with a few percentage points more of an ABV boost.
You'll still see the classic higher ABV at the start of the run and then the steady decline as the run progresses.

[ThomasBrewer]

I had a chance to run the rig this morning. The plate filled during startup, overflowed into the downcomer for a while during heads collection, and remained just below the level of the downcomer(~80%) the entire run. The column has some uninsulated sections, so there was a small amount of reflux returning to the plate throughout the run.

Using the bubble plate seemed to really help with concentrating fores and heads, but tails seemed to come in a lot sooner than usual. Whether that was due to the plate, or increasing the power to keep the collection rate constant, is unknown.

Boiler Charge - 6gal @ 30%
Startup - 5500W

Power reduced to 15% (30ml/min) - 4 pints collected, heads faded out quickly after 3rd jar
Power increased to 20% (50ml/min) - 12 pints collected
Power increased to 25% to keep 50ml/min - 3 pints collected
Power increased to 30% to keep 50ml/min - 3 pints collected
Power increased to 37% to keep 50ml/min - 2.5 pints collected

Connected parrot after tails were obvious, and tails collected until 20% for feints.

Before Airing (preliminary testing off the still):

Heads - 4 pints
Hearts ~ 9 pints
Tails ~ 11.5 pints

All told, it was an interesting run. The plate never dried out. Thinking critically, there's no way that happens with simple wet steam. You'll always have some feed steam condensing when interacting with the tray full of a higher boiling point liquid. If the tray reaches 212F, there's no alcohol left in the boiler. The small amount internal reflux present also ensured this.