Continuous Column Stripping Plates

Bolverk

Howdy all,

I'm working on my steam injection 4" continuous column (8 plates at 4" spacing (9 if i can fit them)) and I'm stuck on the stripping plates.... I've got a serious case of decision paralysis.

It looks like some Russians have had great success with dual flows but I can't get any details on the plate specs. Perfs with a downcomer also look like a solid option, but again it doesn't seem like anyone has worked out the hole size, how many, and down comer size to maximize a 4in columns capability... only extrapolating off larger setups (That I can find).

I picked up some 16g ss sieve plate with .25 hole on .375 offset spacing but after cutting them out to 4" it's like 58% open and I don't think my 4500w element is going to be enough to hold up that up long enough to strip the alcohol out.

I'm thinking about 44 3/16 (.1875)" holes with a 3/4 (.75)" downcomer. I'm willing to make just about anything, I just need a decent starting point.

Can I get your guys thoughts on how I should proceed?

Thanks,

DeltaArtisan

I bought some custom made 4" copper plates from SD and they have been working extremely well at up to 1.8 liter per minute ish feed rate in with wine at 13% alcohol ish and 30 to 55% alcohol out depending on how much power and antifoam I used. I don't know the % open you will have to check with Jeff and Larry. I have to review old logs to see that the alcohol volume out was , but that was early on before I really learned how to optimize with heat recovery and anitifoam. I will likely do some more work soon to see how I can optimize them and will share the results.

I moved on to an 8" stripper with 4 procap plates on double crystal dragon spacing and have been running 5 to 8 ish Liters per minute with 13% input and 71% alcohol output. It runs well but antifoam mixing is key to good performance

Bolverk

So the new plan is 24 holes spaced at 5/8" I'm going to start at 3/16" (4.7mm) with a 3/4 downcomer and just keep increasing the size of the holes until I get the performance I want. Based on what I've seen of the SD stripping plates I'm more inline with their design but I'm keep the holes a bit further apart to allow me to increase the hole sizes.

Smaug

@Bolverk said: So the new plan is 24 holes spaced at 5/8" I'm going to start at 3/16" (4.7mm) with a 3/4 downcomer and just keep increasing the size of the holes until I get the performance I want. Based on what I've seen of the SD stripping plates I'm more inline with their design but I'm keep the holes a bit further apart to allow me to increase the hole sizes.

I feel like that should work nicely. If you don't have enough power to keep the plates loaded then simply fill a hole or two etc.

Bolverk

My only concern is that 3/16 (4.7mm) will still be too big for my 4500w... I guess I could start with 1/8 (3.1mm).

grim

Always wondered if you could stack two plates per tray, and rotate the plates to open/close the hole diameter.

Your openings wouldn't be perfect circles, but you'd have a variable open % tray.

punkin

Ace thinking.

Smaug

@grim said: Always wondered if you could stack two plates per tray, and rotate the plates to open/close the hole diameter.

Your openings wouldn't be perfect circles, but you'd have a variable open % tray.

Yeah I think when incorporating a wier, just a smaller diameter top plate or a (somewhat) matching top plate with a keyway notch out that allows the top plate to articulate for adjustment would be not too difficult to engineer.

Nice going as always @grim. Sometimes the obvious just needs to be said out loud.

Bolverk

Grim, That's pretty brilliant!

Sadly the hole size decision was made for me when my last 1/8 bit broke halfway through. So all the holes are 3/16

punkin

It would work the same if your holes were big as an orange.

Probs even as big as a grapefruit...... :))

Bolverk

Yeah probably not a whole lot of a difference between the 1/18 and 3/16, I just didn't want to over shoot it and make the plates useless

punkin

Just meant the adjustable theory.

Alex

Good day!

Just would like to share my experience, my present 6" column has 20 plates, 8mm holes with downcomers, finally downcomers pipes have been shorted (Pic #4) for better performance.

Previously I use to work on 4" column (last Pic) with 6mm and 8mm holes, just perforated plates without downcomers.

Actually it showed no difference in quality, depend of power (kwt) which you can supply to your steam generator.

Bolverk

Hey @Alex, I'm glad you commented. Your video here is actually what I'm loosely basing my still off of. Especially the bottom end with your steam non return setup.

https://www.youtube.com/watch?v=aeldFqWt_rE

6-8mm holes is what is looking like will be needed.

So the plan is 6 stripping plates below the feed with 24 3/16 (4.7mm) holes (I'll up these to 1/4 (6.3mm) if need be) but I'm adding a 3/4 (19mm) downcomer that will sit in the liquid bed of the plate below and 2 standard bubble cap plates above the feed.

Learning from @Mickiboi's epic thread, my hope is that by removing the boiler from the equation (doing the non return steam setup in @Alex's video), it will be less susceptible to the pressure issues a reboiler has. Also, by using plates that are more specifically designed for the larger volume of liquid. (ei higher turn down ratio than bubble caps and what I also hope is a wider operation range than just the dual flow perfs) i can overcome the column spacing issue like in @Alex's video as I'll be doing 4" spacing because of a physical height limitation.

@grim posted this chart on page 5 of @Mickiboi's thread and I'm kinda obsessed...

What does it take to get build a small rig capable of these kind of volumes?

I dunno if it work like I think/hope, but I gotta try it...

grim

That approach of using the threaded rod for the plate assembly is probably the most flexible way to R&D this.

For a long time, we were obsessed with capturing that plate in a way that prevented any leakage between the plate and the wall.

In this application, that gap is entirely manageable. Really, who cares. Sealing the plate to the column wall? Don't bother.

The physical downcomer tube limits flexibility though, I'd imagine you want to be able to easily vary the plate distance to find optimal performance - that's something that's impossible to do when you are using triclamp spool or tees.

I have a huge triclamp spool, 8" diameter, 10 feet long, a bunch of stainless threaded rod, and a bag of nuts and washers. I've been dying to get some time to hang a tree of plates like this.

grim

Still trying to find the link to that paper/textbook. I know I have that full PDF somewhere.

I loved those tables, because for the first time we were seeing column diameters that we were familiar with, and not some 28 foot wide petroleum column.

Alex

Hi @Bolverk!

You plan to set 6 plates below feed and 2 above, do you also plan to have condenser (we call it deflegmator) above the column? Chart (you added) is mentioned Reflux Ratio 2, that means 2 top plates of the column will work on rectification mode, I have no experience to work with 8 plates only, previously I thought, that short column can not evaporate alcohol completely, however it could work with rectifying plates and return reflux ratio.

Shortly will post on YouTube my latest version of Continuous Columns (with 2 columns), they are high, but may be some ideas could be helpful for your space limitation.

grim

From the tables I posted, where the stripping column has plates above the feed, there is absolutely a partial condenser used to generate a specific amount of reflux.

Reflux ratio can be used to increase the ABV output of a stripping column, however it is at the expense of requiring more energy input.

This introduces far more complexity in control, it also requires larger column diameters as you increase the amount of liquid in the column above and beyond the feed.

Bolverk

@grim, I 100% agree a plate tree would have been best for r&d... I wish I would have thought of that in the beginning, but I already had the plates cut to 107mm for so I'm kinda stuck with these for now, my goal now is to try to tune the plates to work at 4" (going the CD route).

Dude, you've got to post pics when you get around to that build!

And tanks for trying to find that, I went deep down the rabbit hole looking at academic paper on column design and while I didn't find that specific doc I did learn a few things lol.

Smaug

Thanks for contributing to the discussion @Alex.

Bolverk

Hey @Alex,

Yes I'll be running at dephlag at the top above the rectification plates.

I think that's part of where tuning the plates come in... it will have enough active area to flash most of the alcohol but still drain fast enough to prevent flooding.

I assume this is not going to be an easy column to get dialed in.

Bolverk

My hope/theory is that with the steam under 3-5 PSI it will be entering the column at around 225- 230f, so thats about 6-8% more efficiency than at 212f and that will help off set some of the 20% more heat needed with using reflux. On top of that I plan to recover as much heat as I possibly can. Overall I think/hope it'll be a wash in the end.

No one is really doing anything like this on a small scall (that I've seen), so I'm glad to be the guinea pig.

My fun budget is pretty small so I just keep buying parts every payday and adding to the still. It "should" be done in about 6-8 weeks.

Alex

it is not latest version

https://www.youtube.com/watch?v=HZQ9QPNIRGI

in my latest version I use small 24V pump to loop the remaining "tails" and return them in to mash for secondary evaporation.

Alex

@Bolverk said: My hope/theory is that with the steam under 3-5 PSI it will be entering the column at around 225- 230f, so thats about 6-8% more efficiency than at 212f and that will help off set some of the 20% more heat needed with using reflux. On top of that I plan to recover as much heat as I possibly can. Overall I think/hope it'll be a wash in the end.

I think you need to adjust heat according to wort exhausts temperature, important to have completely evaporation of alcohol and the remaining heat will be more then enough for reflux process

Bolverk

That's going to be the challenge....

My understanding is that running a continous with rectification is that you want to balance the column on top vapor temp, but at the same time you want to keep your bottoms temps above 212f.

As I see it I'm going to need to balance the heat input, wash input, and amout of reflux all without flooding AND keeping bottoms waste to a minimum

Alex

Actually we need to control only one Ballance - amount of heat and feed of the mash, in order to reach bottom temp above 212F (according to pressure, that why we have pressure sensor). if you have reached 212F, no need to increase more heat, as the remaining heat is more then enough for reflux process, top vapor temp is uncontrolled, water stream in dephlegmator should be enough to return all vapors, water feed of the steam generator should be auto. reflux proof you can control by taking out amount of product, less taken more proof, nut risk of flooding reflux part.

I have posted one more video with English comments, it is latest combination of my continuous column with reflux mode.

probably it will be final design, as it showed a good results, only steam generator should be replaced by the electrode system.

https://www.youtube.com/watch?v=lBVenlvo4Nk

Bolverk

I think I understand...

So fire up the element at a fixed power and put in wash (preheated) until the temp start to go below 212, then back off to maintain at say 213. Then increase reflux to my desired output abv (for me this will be 60-65%)?

Alex

exactly! first start with water feed (instead of mash) adjust and fix power, when reached 212 with normal atmosphere pressure, change feed to mash, pressure in column will increase due to density of mush, therefore bottom temp should be higher then 212, keep reflux full return with ratio 0 for a some period of time, then adjust to your desired output abv.

in such system it is much easier to control output product stable abv "by liquid" instead of "by steam", those you do not need to control Top temperature.

Smaug

@Bolverk said: That's going to be the challenge....

My understanding is that running a continous with rectification is that you want to balance the column on top vapor temp, but at the same time you want to keep your bottoms temps above 212f.

As I see it I'm going to need to balance the heat input, wash input, and amout of reflux all without flooding AND keeping bottoms waste to a minimum

@Bolverk, here at SD we are using the head temp of the beer column to control the beer feed rate rather than effluent temps.

Since we run a two column still we don't rely on any temps from the spirit side to govern the beer feed.

I feel I may have confused you in previous posts here and about with respect to temp control points on the still? Having the spirit section mounted to the top of the beer column is not quite the same as what we typically do here at SD. Nothing wrong with that by the way. Its just that the theory behind running the still is a bit different.

Also, each target temp (at the top of the beer column) can render a different result ( flavor profile) in the finished spirit. One degree difference makes a difference.

We have found that 91C thru 97C at the top of the beer column still provides plenty of heat at the base to ensure that no alcohol goes down the drain and provides additional operating range as well as the ability to easily manipulate and influence the flavor profile of the finished spirit.

We have also found that 10 plates can indeed render out all usable alcohol. I believe some of the lads here have had good success with even less plates. I digress.

I personally like 95 C best on the 4"

So we have a temp control point at the top of the beer column. This is the primary driver.

For additional tools to manipulate the operating range we have a control point in the reboiler. Then another control point just above Dephlegmator # 1 which essentially sits directly on top of the reboiler. And then the last major control point above Dephlegmator # 2 which ensures a slow trickle of heads constituents to the heads condenser. The remaining vapor is knocked down and pulled off as liquid at the preferred plate level according to the desired flavor profile and ABV. Those product draws can be installed at any plate level. All of this to ensure the widest possible operating range that gives the operator the ability to have multiple ways to influence the flavor profile of the finished spirit.

Anyway, I guess my point is to have discussions that the do not pigeon hole the topic or operating principle into an absolute way of thinking when in this case there are multiple ways to solve the problem.

I'll pipe down now as not to convolute the discussion and detract from Alex's information sharing.

Bolverk

Thanks @Alex.

@Smaug, thanks. no the confusion came from someone else. I see what you're saying that is/was my understanding until I tried to do this single column idea.

I guess what I'm building more closely emulates the beer column at micthers and fingerlakes and therefore was thinking I'd need to emulate their operating procedures... ie maintaining a head temp from 195-205. This "should" by default mean my bottom temp is over 212 if your findings of 91-97c for the SD beer column carry over to this type of design as well.

Since the beer is actually the liquid going through the dephlag the beer feed rate would be tied to the reflux rate. I assumed I'd have to find that balance of feed rate and reflux to heat input.

I could put the dephlag on a tee'd off beer feed to give me more control over the reflux independently of the beer feed.

Alex

@Smaug said: I'll pipe down now as not to convolute the discussion and detract from Alex's information sharing.

Good day @Smaug,

Could you please advise me where I can find your two column run process or any drawing, it is really interesting how you set up columns and which method of product outcome do you use.

Thank you in advance