I'm running my first glass column (CM with 2x33in of copper scrubbers) as I type this and WOW it's an eye-opening experience to see what's going on inside that column. It's like little waves shooting up the flooded portion of the packing.
One interesting thing I've noticed is that the "waves" seem to move faster through the less densely packed portions of the column (I didn't notice a lightly packed section of scrubbers until I started running the thing, and I'm not stopping now).
Brutal wrote:On to what googe is saying, do you have a way to rig that column up with just a sieve plate at the bottom? It could be made into an aquatic environment purely! It would have to be without a drain (in the plate) and I'm not sure how easy that would be to control.
My column sort-of has this already.
The column and gasket sit in the channel and On the other side is a 2in flange for connecting to the boiler.
There's about 3in of column between the plate and the beginning of the scrubbers. When the packing starts to flood with liquid the plate retains much of the falling liquid, with hot vapor blasting up through as it tries to return to the boiler (Reminds me of some flute videos I've seen, but retaining alot more liquid).
At first I was thinking of drilling it out completely, but after reading this thread I might keep it the way it is.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Fri Mar 27, 2015 3:23 pm
by Kegg_jam
skow69 wrote:
It turned out that there was too much pressure in the boiler, so I shut down, removed the
6" old school scrubbie, and fluffed up the top foot or so of packing. On restart, the flood grew from the bottom, just the same.
Ok, this has been nagging at me for a while and has got my spidey senses going. The idea of pressure in the boiler....
How much pressure? How did you know you had it? How much is too much? Is the Aquatic Environment also a pressure inducing environment?
I've been able to duplicate your experience with just plain old scrubbers in a 36" column.... but how tight is too tight for packing?
Re: Environmentally Aquatic Fluidized Bedding
Posted: Sat Mar 28, 2015 2:44 am
by skow69
I could tell it was too much pressure because it started leaking through the crappy seal I had between the boiler and column.
If you have a 36 inch column that is full of water I would think that the pressure in your boiler is probably pretty close to 36 inches of water column which is about 1 1/3 psi. And that would be the maximum you could get as long as the stillhead vents to the atmosphere above the packing. I'd say as long as it isn't leaking it's not a problem, assuming your boiler is robust enough that it won't explode below 2 psi. [Har.]
Sorry for the confusion. I should have spelled that out in the first place.
EDIT: And I now have a positive seal at the boiler.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 4:17 am
by skow69
Well, I've made 4 more runs and have not been able to flood the column. Mar. 5 was the first run with real SPP. That one flooded totally for a short time, then receded to ~half aquatic for half the run, then dried out to normal drippy reflux. Except, that is, for the dancing geysers on top. I always get that. Anyway, for the next run, Mar. 10, the packing didn't change, all I did was rinse it. I filled the boiler to the same level (+/- a couple ounces), and I calculated the dilution for 27% ABV like usual (+/- a couple %, maybe). I got no liquid in the packing at all. I even shut down and stuffed the SPP in tighter -- no aqua. I don't understand what made the difference and it bugs the hell out of me.
I screwed with things some on the two runs after that, but the column didn't flood. On the next run, Mar. 25, I took the SPP out and mixed it together with my old faux spp to fill in the gaps. Then I tamped the mixture into the column as tight as I could. It was still not hard to blow through.
That run is on the video.
You can follow the aquatic frontier as it climbs the column. At 0:40 there is a whif of smoke from an excellent cigar. At 2:30 you get a look at the floor while I adjust the power down. At 2:50 the flood starts to recede. At 3:45 I cranked the power back up to max. The aquatic environment slunk back into the boiler and hid like a frightened turtle.
I should mention that the SPP I am using is not the right size for my column. IIRC I should have SPP made from .015" wire. This is .022". The length and diameter are similarly oversize. I knew this when I got it, but 1) The right size is not commercially available, 2) The price was right, and 3) It's as good a reason as any to build another column. Anyway, the point was that I am not unhappy with the SPP. I didn't expect it to perform as well as it does in a properly sized column.
Now I'm curious about Brutal's idea for putting a perf plate at the bottom. I should be able to do that for the next run, prolly this week.
So the idea is that the plate will not restrict the rising vapor, but will prevent some of the liquid reflux from leaving the column, right? I mean, we are not making a distillation tray so much as building a dam, right? Does that mean that we have less of a fractionating column and more of a lake? It occurs to me that maybe there is a difference between reflux clinging to waybitchin packing in sufficient quantities to fill the column, and plugging the drain so it fills up like a sink. Or maybe not. Maybe it works out the same either way.
Come to think of it, we still haven't seen any hard evidence that this aquatic environment is any more efficient than a well packed "dry" column.
I need something to measure. Some way to gauge efficiency that results in a number for comparison.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 4:37 am
by googe
Have a look at "detonation wave".
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 5:17 am
by Kegg_jam
Dang! That just sounds cool. Detonation Wave! Kapow...!
If I had a metal band I'd call it Detonation Wave for sure....
Maybe I should cut back on the coffee or my heart is going to be emitting a Detonation Wave..
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 7:35 am
by humbledore
Skow I don't see why you say you had no column flooding. That thing was going batshit crazy in the early part of the video. Hard to believe how high it was jumping, the SPP was jumping with it. What volume is your boiler? I know you said keg in here somewhere. On the plates, it is vapor pressure that keeps it loaded. I made some 4" plates that were 11% open and they failed to really load, I went to 8% open and they worked (3/32 holes). I'd rather walk it in from "too much open" than start with "too much closed". Also not sure how it would work with the SPP. Odin had something to say about a packed column over plates in his epic SPP thread, I don't want to quote him wrong but he said it starved the column of liquid.
Edit: I found a packed column worked extremely well over plates...but there was space in between them, at least 4".
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 7:57 am
by cranky
I just love watching that column. It looks like everything in there is dancing. Wish I had some good input for this thread but all I do is stare at it ind go "DAMN THAT'S COOL!!!" I use a plate with holes in it at the bottom of my boka more as a packing retainer than anything else but couldn't tell you much about it other than I get insanely pure spirits when I get everything dialed in. It would be nice to see whats going on in there.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 8:56 am
by skow69
googe wrote:Have a look at "detonation wave".
People who live in glass columns don't throw detonations.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 10:46 am
by DAD300
i,ll get a better look at the video later, but it looks good.
Question. This was all during 100% reflux? Opening the takeoff will slow the violence at the top.
You still need something other than spp on top. Something as a buffer between the hot spp and the reflux. A transition zone...
About the wire diameter...there is a corrolation between the wire dia and the design. So .22 wire wound more open would have the same pass through as .15 wound tighter.
Russian use that fine wire because that's what they get for free. I have used .15, .22 and .32 in 2" column with little dif. The smaller the bits, the less put through with slightly better HETP.
What kind of abv are you starting with and getting to?
Re: Environmentally Aquatic Fluidized Bedding
Posted: Thu Apr 02, 2015 1:00 pm
by carbohydratesn
Man, I love videos of glass columns with SPP. That's pretty great!
I've been having a lot of success with a slightly loose SS scrubber on top of the SPP and a very tightly wound, flat, fat disk of a scrubber on the bottom. One scrubber, pulled into a long thin rope and pulled around itself, tight. It takes some squeezing to get it in the column, but it does a great job of holding some of the fluid up while letting gases pass through.
Humbledore--you are right. What I meant is that I could not maintain the flood. It would climb the column but then recede.
DAD--Yes, all at full reflux. The flood dropped before I could get to takeoff.
I usually have a scrubbie on top to trap the loose packing. After that last run I found about 1/4 cup of packing had blown up through the 3/8" reflux return tube into the LM trap. Surprised me.
My ABV is at or very near azeotrope. I haven't weighed it to verify, but the parrot always shows ~100 on the LM side and ~95 on the VM side. 27% charge. I have been gradually reducing the equilibration period, looking for the limit, since I started using the faux spp. I'm down to no fixed minimum, just whatever is convenient, usually like 5 to 15 minutes. (Remember this is a pretty tall column, 44" of packing, 1 1/2" dia.) I will start being more rigorous about that as we (hopefully) find ways to compare conditions.
I made (actually started) another run to test the "plate". [I want to make a distinction, here. "Plate" sounds like a distillation tray (ala Flute) which this isn't because there is no liquid bed for vapor to bubble up thru. No mingling. So this is just a packing retainer.] I drilled 49 eighth-inch holes in a copper disk and put between the column and boiler. That makes 0.60 sq.in. of open area out of 1.77 total, or 34%.
The flood became impossible to lose. I had to reduce power to 800 watts, from 1800 without the retainer. I waited 15 minutes to see if the head temp would come down. It never did, so I collected 4 oz. to fill the parrot, which read 94% on the LM side. Shut down.
I take this as evidence that a restriction to hold up the liquid is not a direction I want to go. I will remove it and carry on. I won't post the video because it's just the usual vapor streaaming up through a flooded column, which is kind of getting to be old hat. [Har!]
Skol
skow
Re: Environmentally Aquatic Fluidized Bedding
Posted: Fri Apr 03, 2015 4:05 pm
by Brutal
Its possible that the flood falls because the alcohol % in the column rises. The lower boiling point alc mixture weighs less. Maybe at the beginning more h20 is being pushed up there and pools more easily?
Re: Environmentally Aquatic Fluidized Bedding
Posted: Sat Apr 04, 2015 1:16 am
by skow69
Brutal--maybe. Would require more brain power than I have available tonight.
It occurs to me that the retainer/restrictor/dam might have value in a different still. Didn't want to give it a bad rap. I had to reduce power cuz the boiling liquid on top was up into the horizontal pipe and sounding pretty scary. RC was still knocking it all down but the reflux return line (3/8") was overloaded or blocked by the boiling liquid or...yadda yadda. Just didn't need the complication.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Sat Apr 04, 2015 2:42 pm
by cranky
Thank you Skow69, I have a 1.5" X 42" (packed section) Boka packed with lava rock with a retainer plate that has as many 1/4" holes as I could fit. I reach azeo. on it and now seeing your video I can see what is going on inside. I can hear what is going on but thanks to your video and description I can now understand exactly whats happening.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Mon Apr 06, 2015 12:08 am
by skow69
That's awesome, cranky. I've taken so much from this community it just tickles the hell out of me when I can actually help somebody.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Tue Apr 07, 2015 1:10 pm
by DAD300
skow69, I see this experimenting as all good.
The idea that the plate held the aquatic environment with less power sounds like a positive step to me. It would seem a step in finding the right power vs vapor speed to balance the flood.
I've had conversations about equilibrium and stacking the column while using SPP also. Once the vapor passes through 40 theoretical plates, you're stacking 95% pure "something" at the top. And holding that pure a vapor at the top, probably renders refluxing for purity unnecessary. And may be causing the pressure (although small) that induces the shock wave effect.
SPP's mass transfers the heat a lot better than other packings or physical plates. I have had trouble measuring a one degree dif from bottom to top of a 36" column. If the packing is that hot, reflux will not penetrate it. My only fix was to remove the insulation from the top third of the column, have Scrubbie in the top and a bigger void before the takeoff.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Tue Apr 07, 2015 2:47 pm
by carbohydratesn
My only fix was to remove the insulation from the top third of the column, have Scrubbie in the top and a bigger void before the takeoff.
Well it's good to hear that helps things - a side effect of adding a stainless head to my bok is that I'm going to gain about a foot of empty space above my packing, instead of the few inches I have now. I'll pay attention to how that helps with things, I have a feeling it'll make maintaining an aquatic environment without actually flooding a *lot* easier.
Have you tried running it with no insulation on the column at all? How do you think that changes things vs. only having the top 1/3 uninsulated? I can't think of any benefits to leaving 2/3 of the insulation on, but I don't have thermometers up and down my column, or nearly as much experience as some of y'all. Subjectively, an uninsulated column has felt like it runs better than a partially insulated one, for me. Is it that you can establish a narrower temperature gradient that way?
Re: Environmentally Aquatic Fluidized Bedding
Posted: Tue Apr 07, 2015 4:46 pm
by DAD300
I can get a gradient with partial insulation. I think blocking the wind is as or more important than insulating the whole thing.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Tue Apr 07, 2015 5:54 pm
by carbohydratesn
That is definitely a good reason, didn't even think of that - I might try some insulation again, now that I've gotten the hang of it. That extra stability could be nice. Thanks!
Re: Environmentally Aquatic Fluidized Bedding
Posted: Sun May 24, 2015 4:05 pm
by cranky
Skoow69,
I have been working on a couple of glass setups the past few months and just finished the 2nd one, although the first was disassembled to do it. The wife bought me a 50" long 95mm (roughly 3.5" ID) Borosilicate tube which I just got up and running a few days ago. I am running lava rock instead of SPP so my observations may not apply but I just did the cleaning runs and on the sacrificial runs there was no surging (or pressure wave/detonation wave or whatever people are calling it). When I run my 1.5" boka I can hear exactly what your video shows happening, namely this surging, so I am wondering is this a phenomenon associated with smaller diameter columns or something else? I also ran the first sac run with no packing whatsoever just a retainer plate that has a bunch of roughly .22" diam holes with one 3/8" hole in the center. This plate will hold an inch or two of fluid by itself if run hard but I observed that the vapor passing through this retainer plate was actually swelling in (I think) a clockwise direction at about the same rate as the surging you observed. I am just wondering if you or any other member has observed this swirling and I wonder if this is the cause of the wave.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Sun May 24, 2015 8:48 pm
by InglisHill
Cool Skow, fkn cool!
Re: Environmentally Aquatic Fluidized Bedding
Posted: Mon May 25, 2015 11:49 am
by skow69
DAD300 wrote:skow69, I see this experimenting as all good.
The idea that the plate held the aquatic environment with less power sounds like a positive step to me. It would seem a step in finding the right power vs vapor speed to balance the flood. I see what you mean. In this case I took it out because it brought the ABV down too much and I didn't want to spend the time refluxing to bring it back up. I thought it was interesting that the fully flooded column was so much less efficient than partially. Which is not to say that the flooding itself was necessarily the cause. I had to reduce power also, and the ABV is the result of the whole interrelated package.
I've had conversations about equilibrium and stacking the column while using SPP also. Once the vapor passes through 40 theoretical plates, you're stacking 95% pure "something" at the top. And holding that pure a vapor at the top, probably renders refluxing for purity unnecessary. And may be causing the pressure (although small) that induces the shock wave effect.
SPP's mass transfers the heat a lot better than other packings or physical plates. I have had trouble measuring a one degree dif from bottom to top of a 36" column. If the packing is that hot, reflux will not penetrate it. My only fix was to remove the insulation from the top third of the column, have Scrubbie in the top and a bigger void before the takeoff. I would like to explore that. Do you remember what that temperature was? Did you draw any product and test the ABV? Did you try just reducing the power? What effect did that have?
Re: Environmentally Aquatic Fluidized Bedding
Posted: Mon May 25, 2015 12:10 pm
by skow69
Regarding the temperature gradient, I'm thinking that the temp at the bottom will be determined by the ABV in the boiler, raised by one distillation, that being the boil that got the vapor out of the pot. The temp at the top will be determined by the ABV of the product available at the output. So the goal would be the maximum difference between the two, regardless of where in the column the change occurs. Does that sound right, or is there something else going on?
Re: Environmentally Aquatic Fluidized Bedding
Posted: Mon May 25, 2015 12:43 pm
by skow69
Cranky,
1 Holy shit that's a big hunk of glass!
2 You must be a really good shot to space those .22 cal holes evenly.
3 I assume you're running the new column on the same boiler as the old one. I would bet the failure to fluidize is just the ratio of power to column volume. It would take a lot more power to fill the 3 1/2" column than the old 1 1/2" boka. Good thing you have an understanding wife, cuz it sounds like she needs to get you some bigassed heating elements now.
4 I haven't noticed any swirling, but then I haven't been looking for it. I will be next time.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Mon May 25, 2015 3:42 pm
by cranky
skow69 wrote:Cranky,
1 Holy shit that's a big hunk of glass!
Yes it is but it isn't as heavy as 7 dollar store mugs stacked on top of each other and it was a lot cheaper than copper. It came from an outfit down your way, maybe the same one you got your tube from
skow69 wrote:2 You must be a really good shot to space those .22 cal holes evenly.
I am one hell of a shot actually when I drilled the holes I happened to have a #2 drill bit, which is .2210, and I figured that would be good enough
skow69 wrote:3 I assume you're running the new column on the same boiler as the old one. I would bet the failure to fluidize is just the ratio of power to column volume. It would take a lot more power to fill the 3 1/2" column than the old 1 1/2" boka. Good thing you have an understanding wife, cuz it sounds like she needs to get you some bigassed heating elements now.
Yes, 15.5 gallon keg, 5500W element. I actually didn't have any trouble maintaining a fluidized bed but it didn't do that shockwave thing yours was doing. I could easily maintain the flood as high in the column as I wanted right up to the point I shut it down. I was just playing around during the cleaning runs and I need to learn to run a CM rather than a boka and try to figure out this whole fluidized bed thing but I have 20 gallons of Birdwatches waiting to go as soon as I have time to play. My wife is very understanding but in all honesty the neutral is for her and the big ass column will let me spend more time doing things she wants me to do rather than running
skow69 wrote:4 I haven't noticed any swirling, but then I haven't been looking for it. I will be next time.
Once I had the packing in the swirling wasn't visible, it was very noticeable when I I had an inch of fluid on top of the packing retainer and no packing. I'm thinking the swirling is probably caused by the turbulence of the vapor abruptly squeezing down to 2" to exit the keg then abruptly expanding to 3.5" in the column. It was actually quite interesting to watch. I kind of wish I trusted youtube enough to post a video to show what I'm talking about. I also kind of wish I had taken a video but unfortunately I didn't.
Re: Environmentally Aquatic Fluidized Bedding
Posted: Tue May 26, 2015 1:10 am
by skow69
So you have only run packed with water or vinegar, then, no alcohol, right? That can change all sorts of things when you add alcohol. I'm still surprised you didn't see any bubbles, though. Watch a saucepan boil on the stove. Bubbles form at the bottom, right on the heat source. They rise briskly to the top, and burst through the surface like ... (do I have to say it?) ... farts in a bathtub. More energy makes more bubbles until you get a full rolling boil, but it's still a result of those bubbles that form at the site of energy input. Turn the power down and watch. Fewer and fewer bubbles until you get down to tiny ones that leave the bottom but don't seem to make it to the top. Could it be that your still is running like that? At the lower end of the boil, and the bubbles don't make it high enough to be visible? I think you need either a borosilicate boiler, or another 5500 watt element to test the hypothesis. Or you could run an 8% wash and see what happens.
actually when I drilled the holes I happened to have a #2 drill bit, which is .2210, and I figured that would be good enough