Dephlegmator not needed to reflux?

[fiery creations]

Having trouble driving my flute. Today I did my first neutral spirit run with it fully assembled, using all 10 bubble plates. I have no idea why, but I seemed to be only reaching 92/93% ABV. I started with 15 gallons of 30% low wines.

I put it into full reflux for 30 minutes, and then began choking off water to the dephlegmator. It got down to a point where even with it completely off I was getting almost no output. So I left it off and cranked up the heat input a little at a time until I started collecting. Even with it off I seemed to be getting plenty of reflux. The top plate was loaded and bubbling away.

In a tall plated still, is passive reflux enough?

First jar of fores was 95%+. 1/4 turn on the needle valved stopped output so I cranked the heat a little. ABV dropped to 92%. I went back and forth between no water to the deph (using power to control output) and more power with 1/4 turn on the needle valve. It was such a fine line between completely flooding the top plate. Like a half of an amp of power fine.


I know a lot comes with experience but I'm not sure what to be shooting for. The least amount of power required to keep the top plate loaded, not using the deph at all? Like I said I had plenty of passive reflux happening with it completely off. As much power + more deph water as possible to knock it down without flooding the plate? Neither option seemed to increase ABV.


Not sure if I'm overthinking this, but I'm bummed I don't seem to be reaching azeotrope after a major PITA to get it somewhere to run with all 10 plates, when with half the plates it was absolutely pissing out azeo. Same ABV boiler charge. Advice?

It did seem to give me some realllly neutral smelling product. But why no azeo then? Furthermore, I went from what smelled like fores straight to hearts. Is this from using sodium bicarb to clean it up? I was NOT expecting my distillate to go from cloudy tails to crystal clear from using it. What exactly is taking place there? I was left with some gross orange powder at the bottom of my low wines. Was that ok to run?

[shadylane]

A plated still is the wrong tool for making azeo.
A packed column would work better.

[fiery creations]

A plated still is the wrong tool for making azeo.
A packed column would work better.

Right on, thanks for the tip. Any advice on the questions relating to what I'm using? If I'm getting so much passive reflux at the top with the dephlegmator shut off that the plates fully loaded, is there any reason to turn it on and increase power?

[The Booze Pipe]

It’s my understanding that neutral and azeo can be two different things. But that’s debatable ha. If you’re getting good separation in the column, and producing a neutral distillate, you’re good to go. No need for azeo.
But ya, a better tool for the job is a packed column. Unless you added 10 more plates

[Sporacle]

Generally speaking all plates should be loaded evenly.
The purpose of the dephlegmator is to partially condense vapour to enable the plates to load correctly.
You should be able to balance your output and ABV with power and flow.
Flow control requires a needle valve.
The amount of flow through the dephlegmator is fairly minimal in my experience, hence the requirement for a needle valve.

Plated columns take time to react input changes especially flow, this is due to the volume of water in the dephlegmator has to change temperature in order for the change to be enacted.

As Shady said it's not the right tool for a neutral, a packed column would serve you better.
Having said that 10 plates should get you a reasonably clean product.

My advice is slow down your adjustments and get a needle valve if you don't have one

[shadylane]

Any advice on the questions relating to what I'm using? If I'm getting so much passive reflux at the top with the dephlegmator shut off that the plates fully loaded, is there any reason to turn it on and increase power?

Sounds like the dephleg has too large of thermal mass.
Got any pics of the rig?

[fiery creations]

Any advice on the questions relating to what I'm using? If I'm getting so much passive reflux at the top with the dephlegmator shut off that the plates fully loaded, is there any reason to turn it on and increase power?

Sounds like the dephleg has too large of thermal mass.
Got any pics of the rig?

Sure do. Don't laugh, part of these reason I'm bummed it didn't give the the results I expected was because of how much effort and money it was to get some privacy for it to run outside...

I understand a packed column is better. I still have my 2" but couldn't stand the slow output. I went to 10 plates to get "neutral enough." It seems to be as clean as my packed column, I'm just confused why when I ran it with half the plates I was getting azeo with fast output but this time nothing seemed to reach it.

[fiery creations]

It’s my understanding that neutral and azeo can be two different things. But that’s debatable ha. If you’re getting good separation in the column, and producing a neutral distillate, you’re good to go. No need for azeo.
But ya, a better tool for the job is a packed column. Unless you added 10 more plates

I guess that's true. If it tastes neutral and good it shouldn't matter. Guess I'm just scratching my head wondering why, and if the dephlegmator is even necessary in this configuration.

Generally speaking all plates should be loaded evenly.
The purpose of the dephlegmator is to partially condense vapour to enable the plates to load correctly.
You should be able to balance your output and ABV with power and flow.
Flow control requires a needle valve.
The amount of flow through the dephlegmator is fairly minimal in my experience, hence the requirement for a needle valve.

Plated columns take time to react input changes especially flow, this is due to the volume of water in the dephlegmator has to change temperature in order for the change to be enacted.

As Shady said it's not the right tool for a neutral, a packed column would serve you better.
Having said that 10 plates should get you a reasonably clean product.

My advice is slow down your adjustments and get a needle valve if you don't have one

Have a needle valve. 1/4 turn was max I could open it, and it required pumping up the power. With it completely shut off it was still refluxing like crazy through the top sight glass. Guessing because it's so far away the passive reflux is enormous? I spent over an hour waiting 5-10 minutes between each adjustment.


Main question is, if I'm getting a ton of reflux at the top with the dephlegmator completely off, and all plates are loaded fairly evenly, should I even bump up the power and turn the deph on? I tried both ways and couldn't tell any difference in practice, just want to make sure there isn't something I'm unaware of happening here.

[Sporacle]

You'll get reflux from the dephlegmator with it shut off initially until the water temp matches the vapour temp.

I didn't realise that it's SS, I would look at insulating everything.
What was the ambient temperature?

So turn the flow to full on the dephlegmator
Power your still up until you have your plates loaded and bubbling away happily.
Decrease your water flow until you have product flow
Continue to decrease water flow and measure your takeoff rate and ABV
If your plates drop out then increase your power, wait and recheck.
If you have a good needle valve and a power controller then there is no reason why you shouldn't be able to run the still efficiently

[Yummyrum]

Are they Perforated (sieve) plates or Bubble caps ?
Sieve plates will always need a defleg to keep them loaded . Bubble caps do tend to stay loaded . As the plate liquid level is set by the downcomer height.

If you run it with forced reflux , ( using the defleg) you should be able to run it at a higher takeoff rate for the same purity as if you are just running with passive reflux


How cold is it out there in the tent .
I agree with Sporicale and would expect it to behave differently if you wrap a blanket around it ( with peek holes here and there to see a few windows).

[fiery creations]

Are they Perforated (sieve) plates or Bubble caps ?
Sieve plates will always need a defleg to keep them loaded . Bubble caps do tend to stay loaded . As the plate liquid level is set by the downcomer height.

If you run it with forced reflux , ( using the defleg) you should be able to run it at a higher takeoff rate for the same purity as if you are just running with passive reflux


How cold is it out there in the tent .
I agree with Sporicale and would expect it to behave differently if you wrap a blanket around it ( with peek holes here and there to see a few windows).

It was about 50F outside. They are bubble plates.

1) So turn the flow to full on the dephlegmator
2) Power your still up until you have your plates loaded and bubbling away happily.
3)Decrease your water flow until you have product flow
4)Continue to decrease water flow and measure your takeoff rate and ABV
If your plates drop out then increase your power, wait and recheck.
If you have a good needle valve and a power controller then there is no reason why you shouldn't be able to run the still efficiently

That was my exact procedure. But at step 4, I had to completely shut it off to get product flow. And the plates didn't drop out. I left it this way for a good 30-60 minutes. The shutoff deph kept refluxing despite zero water flow through it.

If you run it with forced reflux , ( using the defleg) you should be able to run it at a higher takeoff rate for the same purity as if you are just running with passive reflux

If I opened it up more than 1/4 turn I had to up the power a ton to get and product, which also caused the top section to start flooding. I spent the majority of this run doing small inputs and then waiting for an effect. I really don't think it was any type of "lag."


From what I'm gathering reflux is reflux. Whether forced with the dephlegmator or passive from a tall column and cold ambient temps. Since this output seemed identical with each and I couldn't put more power in without flooding it, I guess it doesn't make a difference which way I run it.

[Sporacle]

which also caused the top section to start flooding

Can you give us a definition of your flooding, was the entire sight glass liquid top to bottom or was it around halfway?
Where was the liquid level in relation to the comers?

[Setsumi]

Use enough energy/power to run your reflux condenser.

[Saltbush Bill]

Remove a few plates, try with 6 or 7 and see if there is a difference or not.
Bubble plates will stay loaded with very minimal reflux from my understanding/ what I have been told.
In a cold climate with a tall column you may be able to run without any forced reflux at all.
I'm only guessing at some of this because I live in a hot climate, and use perforated plates which behave differently.
I've made clean enough spirt to make a good gin using only 5 plates and clean strip from a wash like SSS.
If your top plates are already flooded it's pointless to add more power.....but I think you already know that.

[Swamptrout]

How big is the boiler? My guess is the boiler charge for that many plates is on the low side.

I run the same size charge on my 4 plate still and it runs OK, if i borrow my brothers big boiler and double the charge it runs excellent.

The additional volume gained by the extra 6 tees is going to be substantial.

Also what power are you throwing at it ?

[Swedish Pride]

How do you judge that you have a ton of reflux without the RC on?

I'm going to go out on a limb and assume that it's because the plates stay loaded?
It's how your comments reads to me if that's wrong I'm sorry the next bit will not apply at all.

Full disclosure, I've never ran caps, I have sieve plates, with all that said, here is my understanding of it.

Caps don't drain so you will always have them loaded even with the RC off, with the RC off they would work like shallow inline thumpers.

You'll need the RC on to force reflux thus running it like a plater.
If it floods back off on the power.

I made neutral last weekend, just 3 plates and a 2ft packed section .

Try removing the plates from the top half of the assembly, fill it with ss scrubbies and give it another go, bet you it will be closer to what you want.

Then try to remove enough sections so you can run it inside, running in that setup will get old soon.

Best of luck with it

[Saltbush Bill]

my first neutral spirit run

Does this mean you are running straight wash or low wines,, most folk running plated columns run straight wash.
Would just be handy to clarify that.

[MooseMan]

He's running 15 gal of 30% low wines Bill.

Disclaimer, I don't own and have never run a plater, but the below sentence from Swedish Prides post, stands out to me considering the OP is running a big tall stainless column, uninsulated, in cold air.

"Caps don't drain so you will always have them loaded even with the RC off, with the RC off they would work like shallow inline thumpers"

[Saltbush Bill]

Thanks Moose I seem to have somehow skipped over that part more than once.
If that is the case I'd be inclined to try running straight wash as an experiment to see what happens.
Plated colums also dislike breezes, especially cold breezes.
My guess is that ,that one is getting plenty of breeze in its current location.
At least that holds true of the perf plate columns that Ive owned and run.

[Stilljoy McFlavour]

I run my 4 x 4” bubble plates with a 2” deflag; it hardly requires flow. My needle valve is usually less then 1/8 of a turn open when taking off product. I can turn the deflag off entirely but then takeoff speed is slower (because less power input ).

Btw, it is still a flavored product, however when running with more power and limiting take off speed by increasing flow to the defleg, I am able to push purity close to 96%. In this case take off volume is less then 1 liter/hour as opposed to approximately 2-3 liter during a regular run.

I guess bubble plates just don’t require a lot of additional reflux

[greggn]

Got any pics of the rig?

Sure do.

Please tell me that you have that column supported in some way. Have you tested its stability with an empty boiler ? I'm a little concerned that you could remove enough volume during a run to make that tip.

[shadylane]

Main question is, if I'm getting a ton of reflux at the top with the dephlegmator completely off, and all plates are loaded fairly evenly, should I even bump up the power and turn the deph on? I tried both ways and couldn't tell any difference in practice, just want to make sure there isn't something I'm unaware of happening here.

Two possibilities, one the deph has a leak, or more likely the def is too effective.
It's going to take time for the water in the deph to get hot.
Set the water flow to a fast drip or at most a trickle and wait.

[haggy]

fiery,

First Concern - 30% abv in the boiler

Dephlegmator not needed to reflux?
Post by fiery creations » Sat Apr 06, 2024 4:21 pm

Having trouble driving my flute. Today I did my first neutral spirit run with it fully assembled, using all 10 bubble plates. I have no idea why, but I seemed to be only reaching 92/93% ABV. I started with 15 gallons of 30% low wines.

First jar of fores was 95%+. 1/4 turn on the needle valved stopped output so I cranked the heat a little. ABV dropped to 92%.

With a low wine of 30% abv in the boiler, the vapor flow up the column is significantly increased vs a 10% abv wash. So the bubble cap plates can be flooded at a lower power input. I researched many bubble cap posts and found a relationship where flooding starts vs the power input vs boiler abv. From Page 2 of the following thread, here is that relationship:

viewtopic.php?t=88352&start=30

You see that the 4" column line at 30% abv can have flooding at about 2400 watts. Now, you have not said what watts ( or amps you were running ), but you probably were just under 2400 watts. Then when you raised the power a little, you saw flooding. ( as represented by the product abv dropping from 95+% to 92/93%. ) Flooding causes entrainment of lower abv liquid from a plate carried up to the above plate and diluting the abv in the above plate. This happening on all plates can reduce the overall product abv.

So run a wash next and you can run higher watts - or lower watts - and not have entrainment.


Second Concern - Turning the cooling water ( cw ) on and off

I went back and forth between no water to the deph (using power to control output) and more power with 1/4 turn on the needle valve.

Have a needle valve. 1/4 turn was max I could open it, and it required pumping up the power. With it completely shut off it was still refluxing like crazy through the top sight glass. Guessing because it's so far away the passive reflux is enormous? I spent over an hour waiting 5-10 minutes between each adjustment.

As Sporacle said,
It is conceivable that the water in the shell of the defleg can still condense the vapor coming into its tubes for a good period of time after the cw is shut off. The water in the shell is stagnant, so the heat transfer is at a low rate. The temperature difference for heat transfer starts at about 110 F and as water heats up decreases to about 20-30 F while still cold enough to condense vapor. It could take 10 minutes for this water to heat up.

So turning the cw valve on and off every 5-10 minutes, could replenish the cold water temperature in the defleg shell and keep condensing all or much of the vapor. As Shadylane said, "Set the water flow to a fast drip or at most a trickle and wait."

I can get you in the ballpark with an estimate of the cw flow rate required, see the end of this post.

And +1 on this from Mooseman:
"Caps don't drain so you will always have them loaded even with the RC off, with the RC off they would work like shallow inline thumpers"


Third Concern - Not enough information given in the post

To really understand what is happening, we need to know:

What was the product take-off rate in L/hr?
What watts were run and change to what level?
What was the cooling water flow rate and exit temperature?
How much does the cw flow rate change vs cw valve setting?
Did you try a 1/8 valve setting?
What are the defleg tube dimensions and how many tubes?
Did the cw valve leak? Was no flow coming out?

Once you get several runs under your belt and know your still, all this data is not needed. But, for just starting now, it would be very helpful.

Can you go back and get some of those numbers? Or next run, try to get this information, then we can better diagnose any problems.


____________________________________

You have received some good info in this thread. To summarize;

+1 on the number of plates. Six or seven might be enough to get a good neutral.

And +1 Try to get around a 1 L/hr +_ product rate for neutral. Reflux rate will be good (high). For more flavor, go to 2 to 2.5 L/hr product rate and get a lower reflux ratio.

And +1 Run a wash next time. Try to run at 3000 to 3300 watts for a neutral. Less power 2600 to 2800 watts for more flavor.

Also, Check and calibrate your cw flow rate vs valve setting off line to see that relationship and how much the cw flow rate changes vs valve setting.

Your Next Run
For your CM column, I estimate you will need about 400 -800 ml/min cw flow rate for a neutral product run to get about 1 L/hr product rate at 3300 watts using wash. For a flavored spirit run, three bubble cap plates and 2.0 L/hr product rate at 2800 watts using wash would only require about a 200-350 ml/min cw flow rate.

haggy

[fiery creations]

which also caused the top section to start flooding

Can you give us a definition of your flooding, was the entire sight glass liquid top to bottom or was it around halfway?
Where was the liquid level in relation to the comers?

It was about halfway up the sight glass before I was able to correct it.

Remove a few plates, try with 6 or 7 and see if there is a difference or not.
Bubble plates will stay loaded with very minimal reflux from my understanding/ what I have been told.
In a cold climate with a tall column you may be able to run without any forced reflux at all.
I'm only guessing at some of this because I live in a hot climate, and use perforated plates which behave differently.
I've made clean enough spirt to make a good gin using only 5 plates and clean strip from a wash like SSS.
If your top plates are already flooded it's pointless to add more power.....but I think you already know that.

I used old UJSM for my spirit run and with 6 plates it was pouring out azeo quick. I'll have to try running more SSS through it in that config to see if it's neutral enough. If it is, it sucks I spent so much on a bunch of useless sections.

How big is the boiler? My guess is the boiler charge for that many plates is on the low side.

I run the same size charge on my 4 plate still and it runs OK, if i borrow my brothers big boiler and double the charge it runs excellent.

The additional volume gained by the extra 6 tees is going to be substantial.

Also what power are you throwing at it ?

26gal boiler, only charged to 15 gal. I ended up using 25A with the needle valved cracked 1/4 turn for the last half of the run. More power/water flooded.

How do you judge that you have a ton of reflux without the RC on?

I'm going to go out on a limb and assume that it's because the plates stay loaded?
It's how your comments reads to me if that's wrong I'm sorry the next bit will not apply at all.

Full disclosure, I've never ran caps, I have sieve plates, with all that said, here is my understanding of it.

Caps don't drain so you will always have them loaded even with the RC off, with the RC off they would work like shallow inline thumpers.

You'll need the RC on to force reflux thus running it like a plater.
If it floods back off on the power.

I made neutral last weekend, just 3 plates and a 2ft packed section .

Try removing the plates from the top half of the assembly, fill it with ss scrubbies and give it another go, bet you it will be closer to what you want.

Then try to remove enough sections so you can run it inside, running in that setup will get old soon.

Best of luck with it

Because I could physically look in the top sight glass and see it raining down.

Got any pics of the rig?

Sure do.

Please tell me that you have that column supported in some way. Have you tested its stability with an empty boiler ? I'm a little concerned that you could remove enough volume during a run to make that tip.

No. I set it up empty and short of me completely falling into it empty to knock it over, it was fine.

[fiery creations]

fiery,

First Concern - 30% abv in the boiler

Dephlegmator not needed to reflux?
Post by fiery creations » Sat Apr 06, 2024 4:21 pm

Having trouble driving my flute. Today I did my first neutral spirit run with it fully assembled, using all 10 bubble plates. I have no idea why, but I seemed to be only reaching 92/93% ABV. I started with 15 gallons of 30% low wines.

First jar of fores was 95%+. 1/4 turn on the needle valved stopped output so I cranked the heat a little. ABV dropped to 92%.

With a low wine of 30% abv in the boiler, the vapor flow up the column is significantly increased vs a 10% abv wash. So the bubble cap plates can be flooded at a lower power input. I researched many bubble cap posts and found a relationship where flooding starts vs the power input vs boiler abv. From Page 2 of the following thread, here is that relationship:

viewtopic.php?t=88352&start=30



image.png


You see that the 4" column line at 30% abv can have flooding at about 2400 watts. Now, you have not said what watts ( or amps you were running ), but you probably were just under 2400 watts. Then when you raised the power a little, you saw flooding. ( as represented by the product abv dropping from 95+% to 92/93%. ) Flooding causes entrainment of lower abv liquid from a plate carried up to the above plate and diluting the abv in the above plate. This happening on all plates can reduce the overall product abv.

So run a wash next and you can run higher watts - or lower watts - and not have entrainment.


Second Concern - Turning the cooling water ( cw ) on and off

I went back and forth between no water to the deph (using power to control output) and more power with 1/4 turn on the needle valve.

Have a needle valve. 1/4 turn was max I could open it, and it required pumping up the power. With it completely shut off it was still refluxing like crazy through the top sight glass. Guessing because it's so far away the passive reflux is enormous? I spent over an hour waiting 5-10 minutes between each adjustment.

As Sporacle said,
It is conceivable that the water in the shell of the defleg can still condense the vapor coming into its tubes for a good period of time after the cw is shut off. The water in the shell is stagnant, so the heat transfer is at a low rate. The temperature difference for heat transfer starts at about 110 F and as water heats up decreases to about 20-30 F while still cold enough to condense vapor. It could take 10 minutes for this water to heat up.

So turning the cw valve on and off every 5-10 minutes, could replenish the cold water temperature in the defleg shell and keep condensing all or much of the vapor. As Shadylane said, "Set the water flow to a fast drip or at most a trickle and wait."

I can get you in the ballpark with an estimate of the cw flow rate required, see the end of this post.

And +1 on this from Mooseman:
"Caps don't drain so you will always have them loaded even with the RC off, with the RC off they would work like shallow inline thumpers"


Third Concern - Not enough information given in the post

To really understand what is happening, we need to know:

What was the product take-off rate in L/hr?
What watts were run and change to what level?
What was the cooling water flow rate and exit temperature?
How much does the cw flow rate change vs cw valve setting?
Did you try a 1/8 valve setting?
What are the defleg tube dimensions and how many tubes?
Did the cw valve leak? Was no flow coming out?

Once you get several runs under your belt and know your still, all this data is not needed. But, for just starting now, it would be very helpful.

Can you go back and get some of those numbers? Or next run, try to get this information, then we can better diagnose any problems.


____________________________________

You have received some good info in this thread. To summarize;

+1 on the number of plates. Six or seven might be enough to get a good neutral.

And +1 Try to get around a 1 L/hr +_ product rate for neutral. Reflux rate will be good (high). For more flavor, go to 2 to 2.5 L/hr product rate and get a lower reflux ratio.

And +1 Run a wash next time. Try to run at 3000 to 3500 watts for a neutral. Less power 2600 to 2800 watts for more flavor.

Also, Check and calibrate your cw flow rate vs valve setting off line to see that relationship and how much the cw flow rate changes vs valve setting.

Your Next Run
For your CM column, I estimate you will need about 500 -900 ml/min cw flow rate for a neutral product run to get about 1 L/hr product rate at 3500 watts using wash. For a flavored spirit run, three bubble cap plates and 2.0 L/hr product rate at 2800 watts using wash would only require about a 200-350 ml/min cw flow rate.

haggy

Phenomenal reply, thanks! I'll try to answer with what I can.

Concern 1- I can try a wash, but it seemed like I would have the best results getting a clean neutral using this setup by stripping and diluting, using bicarb to clean them up. I'm not sure about the watts, I think 5500 (220Vx25A?) is what I settled on with the needle valve at 1/4.

Concern 2- That makes sense. Dephlegmator is pretty heft so I didn't even think it may take a lot longer to heat up. There was a point where it ran for much longer than 10 minutes with it shut off (and power lower) and it was still reflux a ton, seen through the sight glass. It was chilly and breezy outside.

Concern 3-

What was the product take-off rate in L/hr? 5.5LPH is what I settled on with ...

What watts were run and change to what level? 25A with needle valve at 1/4 turn

What was the cooling water flow rate and exit temperature? No thermometer, but it was not warm like all my other runs. One 55 gal drum stayed cool the entire run without having to refill or cool it.

How much does the cw flow rate change vs cw valve setting? It looks fairly precise from what I can see in the clear tube. I have both my RC and PC plumbed back together when they exit so I can't really see exactly what the RC is.

Did you try a 1/8 valve setting? Not really. It seemed so hard to even get 1/4 running smoothly even smaller didn't make sense at the time. But now that I see you guys are saying DRIPS may be all that's needed, I shall.

What are the defleg tube dimensions and how many tubes? Couldn't tell you other than pretty big 4" by 6" section.

Did the cw valve leak? Was no flow coming out? Nope. I make sure everything is leak free before starting it up.




From the specifics being asked I'm wondering if this set up just requires some pretty precise control that I wasn't expecting. 1/4 needle vave turn seemed tiny to be already, but you guys mentioned drips. I can control to 0.1A, so maybe the sweet spot really is just it a narrow window. My old packed column was full blast on RC and just adjusting power to control output. A lot less to mess with. Maybe I'm better off calling the extra sections and plate a waste, and going back to the max plates I can fit inside that were giving me azeo at a good rate.

[fiery creations]

Well, I just did my cuts and I'm pretty bummed. I ended up with just a hair over a gallon of 93%. Sure was a lot of work stripping 3 ~20 gallon washes then doing a spirit run for....a gallon.

I wish my 2" packed column wasn't so damn slow. Anyone got any ideas how to convert my 26 gallon boiler with 4" flange to a packed column that spits out azeo?

[Sporacle]

was about halfway up the sight glass before I was able to correct it.

I have no experience with bubble caps.
Half way or just below halfway on the sight glass is where my plates sit when they are loaded correctly.

Could you describe what you saw when you had your plates loaded and column stabilised?

Plus 5.5 lph is absolutely flying and 5500w is a massive amount of power

[fiery creations]

was about halfway up the sight glass before I was able to correct it.

I have no experience with bubble caps.
Half way or just below halfway on the sight glass is where my plates sit when they are loaded correctly.

Could you describe what you saw when you had your plates loaded and column stabilised?

Plus 5.5 lph is absolutely flying and 5500w is a massive amount of power

Have video but can't figure out how to attach it. Plates were all bubbling away at roughly the height of the caps.


5.5LPH is flying for a 4"?

[Sporacle]

Most people I know run in the vicinity of 2 to 2.5 for a 4 inch.
Now that is for 4 perf plates, not to sure on caps.

My thoughts are that you have to much power and your dephlegmator is struggling due to the amount of vapour it has to handle.

I would try full power till your temp gets up to the top section then go to somewhere between 2700 and 3000w and wait for your plates to load, then dial back the flow until you hit a happy take off rate.

These are all generalisation as I haven't seen you run, Haggy's numbers are usually very close to the mark

I just think you are pushing way to hard and need to dial everything back a bit

Good luck

[Saltbush Bill]

5.5L per hour is a crazy speed, noone I know runs a 4 inch at that speed.
As Sporacle pointed out, 2-2.5 lph is about what they handle well.