Pope's 10-plate Continuous Column

[pope]

I came across an air powered diaphragm pump and that’s my top pick so far I think, I emailed a couple other pump makers to ask about performance under these conditions. The 3/8” air powered one I found uses 100 psi service to pump 1 cfm/gallon Up to 1/16” particle size, so should be good here. Problem is it’s expensive.

I’ve thought about gravity with a grant mounted above the top of the column, it and the main reservoir would need a mixer to keep the slurry consistent... I’d still need to get the mash to the grant and keep the liquid level fairly constant to keep the pressure on the feed line consistent right? Other problem is the column will be about 8’ tall so there’s not a ton of space above it. If I had a basement I’d have a little more in the way of options there. Not ruling any pump/gravity feed options out at this point.

[hellbilly007]

Have you ruled out a peristaltic pump? With a consistency of a flour/cornmeal slurry it shouldn't be a problem for a peristaltic pump, by theory anyways

[The Baker]

Have you ruled a peristaltic pump? With a consistency of a flour/cornmeal slurry it shouldn't be a problem for a peristaltic pump, by theory anyways

If you have contacts in the right places you might get one that is perfectly satisfactory but is no longer suitable in an operating theatre.

Geoff

[pope]

I hadn’t because I didn’t even know about them! Those things are crazy. I’ll definitely look into that more too.

[Yummyrum]

I’ve been looking at Parasteltic pumps for a while too Pope .
There seems to be a lot of the same on Ebay etc around the $50 Aud range that have a choice of DC motor or stepper motor ... both can be fairly easily controlled . Problem is they have a max capacity of only around 500mls / min
. And while thats about the rate I’m pushing with around 3Kw , its far from the mark in regards to what you are hoping to push through and I want to up power too .

Seems if you want bigger , it suddenly gets commercial/ industrial grade /size and you’re looking around the $300 mark + controller .

I did think about using a bank of smaller ones in parallel , but it was mentioned elsewhere that pumps in parallel don’t combine well.... IE 1+1 only = about 1.5 not 2 . Not sure how much truth is in that .

So I’m seriously considering building one. It’s just a piece of silicone hose in a semi-circle with a couple of rollers to squish it through . How hard can it be LOL .

[RC Al]

Since your only moving wash, how about an everyday dirty water sump pump, i just bought one that handles upto 3/4" solids for $89au
From what i can tell its an impellor design, there would be Stainless versions out there if the plastic idea dosent float your boat

[pope]

Yummy you could have two injection points so they are just separate feed lines. But yea I noticed that too, I found a 90 gph parasteltic pump but it’s $408.

An air powered diaphragm is looking good - Yamada pumps are like $295 to $380 for 3.4 and 13.5 gpm respectively. With the stronger pump you could get fermenter mixing action through a tee and a couple valves. But damn.

The sump pump idea sounds like a steal! 3/4” solids??

[pope]

Okay I should've called this "Plates & Pumps".

First, I drilled a f*ck ton of holes yesterday... didn't take that long but its tedious. One or two 1/4" holes over-bored and one downcomer hole drifted a little but I think on that one solder will pick up the slack.

[pope]

As for pumps, we've talked impeller sump, brew impeller, flex impeller, parasteltic, diaphragm, and grant/gravity aka no pump.

I've skimmed some internet searches and I think the really solid contenders are:

Brew Impeller - Chugger Max ~$250+ 17 gpm, 1/8 hp, no wording re: solids
Impeller sump - Grundfos ~$210 1/3 hp, no gpm but 3/8" solids handling rating
Flex Impeller - Enoitalia Euro 20 ~$380 1/2 hp 4.4 gpm, no wording re: solids (this has 1.5" tc fittings so its a better built pump than the others)
Parasteltic - Simply pumps PM312 ~$132 1.27 lpm 12vdc (all others are 120/240vac), 'can pump high particulate content slurries', needs controller (+$$), a little worried about viscosity and head height limiting flow too much
Diaphragm - Yamada NDP-15 series ~ $380, 13.5 gpm 1/32" solids. the NDP-5 is $280 and 3.4 gpm but I am thinking the extra flow could return to the fermenter and drive mixing action. This runs on a compressor at 1 gallon per cfm, so I could get my head height and flow (~.5-.7 gpm) no problem.
Gravity - ?? - I would need to rig a grant above the top of the column and keep it topped up; cheapest option would be bucket refill

I am actually thinking the grundfos sump could work well, it would warm the fermenter a bit over time, there should be sufficient overflow that I can pop on a tee and two valves to create a whirlpool stirring action. It also allows for a fermenter to be something more flat-bottomed like my 50-gal stainless stock pot with no ports. But I wanted to lay out all the options and see what the community thinks. Biggest concern with the sump pump is how much ferment will get left behind, but I can tilt the pot at the end of the run too, maybe I hand feed the last gallon like I'm making foie gras.

[pope]

So far, I am getting rejection on the Chugger Max ('slurry acts as sandpaper and erodes the pump') and Enoitalia pumps, though the Enoitalia rep didn't read my first message, saw 'distilling', and told me they don't have 'explosion-proof pumps' rated for abv over 18%, so I had to reiterate my slurry composition. The forum needs a facepalm emoji.

[pope]

Obviously people have a lot on their minds today but since I've had the time (I make soap so work's not too slow but I have more time than usual), I wanted to post an update - all ten plates and downcomers are finished, I've welded on my three sight glass ferrules (a little grinding and polishing left), I added 1" tc ferrules at a 15 degree down slope angle for rtd probes on compression fittings. Overkill but it'll look cool and I can check the temp on three plates and clean without as many issues as a threaded fitting would give me.

I need to source sight glasses still and have a few more welds to do for input and output points, but I did also order a pump. After a lot of research and suggestions here I went with an air driven diaphragm pump, it's not rated for large solids but I'm pumping grain not abrasives so while I'm confident it will handle a flour based fermentation slurry, I will be push testing it with cornmeal slurry as well. I can't find flour at the moment but I'm sure it'll show up on the shelves before I finish my build.

Being in the shop is a nice break from the 10,000 lbs of uncertainty weighing on everyone right now, keeping my hands busy has felt good and feels like one productive thing I can definitively do. Looks like I have some parts to wait for still but I am closing in on at least testing the column in the coming weeks.

[pope]

Closing in on this with all the time I’ve got on this ‘stay at home’, the base and drain/steam injection site is almost finished.

[The Baker]

I like the built-in stand.
I have a piece of stainless tube a bit bigger than that which could be used as a thumper one day....

Geoff

[pope]

Mini thumper! This is a 4” x 12” tube. I have a 5-gal mini keg I use for small spirit runs but I’d still love to build a thumper attachment for it one day, never built a proper thumper.

[The Baker]

Mine is 4 inches x 28 inches.
It has screw on four inch fittings each end with end plates and smaller tubes emerging, and a maybe one inch pipe welded in near one end.
It used to be part of a milking machine set-up and originally had a big paper filter in it.
Got it for ten or fifteen dollars maybe twenty years ago....

Geoff

[stevea]

I've used peristaltics for mash and wash. If there are any solids, they can accumulate at the pump "pinch point" and clog. If there are solids that can settle out, then you have to be very careful to low-slope the upward tubing and/or keep the flow rate higher than the settling rate. With solids, any stop/restart is almost certain to clog. Even the high-temp tubing gets bad kinks after a day of hot liquid use. There is an odd trade-off - smaller diameter tubing is a negative wrt particle size, BUT the smaller tubing has a higher flow velocity - so less "silting". My *opinion* is that all these problems are less likely in fermented wash than mash. Also the peristaltics "slip" when solids are present (even flour). So if you adjust the pump to deliver 1l/minute of water, it might only deliver 0.9l/min of wash.

The ideal is a positive displacement pump. Diaphragm pumps are good at delivery, and not too pricey, but the output is "pulse-y" (peristaltics are pulse-y too). What that does to the column dynamics is a mystery to me. For some reason 98% of all the diaphragm pumps I see are air-operate - so you need to factor in a compressor. Air power is very inefficient - you need a compressor motor ~3x the pump rating. Lobe pumps, & external screw pumps and "Moyno" pumps are smooth, can deliver solids, but most are too large, and way too pricey.

A lot of craft distilleries, and wineries transferring skin+seed 'must' use flexible impeller pumps. I *think* that or the diaphragm are your best bets.

Hope I contributed little to your excellent project Pope. Best wishes

[LWTCS]

100% stevea.
Stumpy prefers the flexible impeller.

[pope]

I think a flex impeller is probably best but I was having a hard time finding something for this scale that was reasonable. I’ll find out later today how the AODD works!

[LWTCS]

Yeah the FI is kinda spendy.

[pope]

Found one that would drive the particle size I’m planning on for about 3.5k and probably 100x the flow rate I need.

[LWTCS]

Oh jeeze...

[pope]

Yea the issue for this nano scale is particle size, and I have a feeling lots of pumps will work for flour and fine solids but on paper no one is going to tell me ‘yes this 1/4” id pump will work for your needs’. Go bigger on your flow rate and the available pumps and cornmeal or even fine cracked corn would be no issue. But for me, worst case washes should do just fine in my pump and I’ll just make single malt, rum, and neutral.

[pope]

Finished the base and top over the last couple days, I may be coming up short on hose adapters for the weekend until I get my hands on more argon. Looking at about ~8’ tall so far, plus my existing 4 to 2” concentric reducer and 2” lyne arm and shotgun condensers. I’m thinking about using chains around the lyne arm of the condenser to steady it to the garage rafters.

Birdwatchers tonight, I supposedly am getting flour on Tuesday to make a flour ferment. Monday is more argon and I can make my hose adapters for the base. I’ve got the parts for one 20 x 2” heat exchanger so I might do that and switch the product condenser horizontal so I can run the mash through it.

[pope]

Welded up the lyne arm and vapor condenser yesterday, brazed together the 3x3/8 copper to the plates for a 3' x 1.5" stainless jacket. The idea is to minimally knock vapor to liquid, then the liquid will catch in the horizontal hx. I've got some vinyl and silicone tubing to cut and crimp still, but that's not a ton of work. Pictures to come!

I should be able to do a cleaning run this afternoon...

No vinegar here but I'll be making a citric acid solution to pump in the top.

[pope]

Finished enough to run. Not even sure what to say, it was a trip for sure. Lots to improve on but in went a 50# sugars' worth BW wash, out came 65% low wines in 2-3 hours. Yield was low for a few reasons. I'll do a write up but if there are any questions I'll be sure to answer in my post.

[Yummyrum]

Good stuff Pope
Look forward to your story ... pics

[pope]

I'll take some pics to back up my story! Honestly it'd be damn near impossible to explain everything without writing a novel if I didn't take pictures.

[LWTCS]

"A trip"?
As in you running around like a one handed paper hanger?
Or, a trip as in ........

[pope]

To review, the system is 10x 8" tall chambers on a 4" pipe with the 1/4" perf holes, 3/4" downcomers, and the condensers are a 1.5"x36" with 3x3/8" copper inners as a vapor condenser, and a 2"x24" with 3x1/2" copper inners as a horizontal low wines to wash heat exchanger. The pump is an air-driven double diaphragm to move the mash slurry/wash through the system to an injection point at the top of the column. Steam injects from a boiler system at the bottom of the column and waste drains out just a few inches below that.

The whole thing ran best with the bottom plate temp at ~207-210F, and the top vapor temp at ~189-192F. ABV seemed to stay around 55-65% regardless, my aggregate abv was 61.7% and my yield was ~4 gal. I should have had like 5.1-5.2 gal but I had a fair amount of splashing and I assume that I had tails losses when running at 205-207F which happened for solid portions of the operation.

Challenges:

1) The oscillation of the diaphragm pump at a low air flow meant some pressure fluctuation, with my current parrot that meant a decent amount of sputtering, spitting, and surging. My hydrometer even ejected, bounced on concrete, and somehow is intact, call it a pilot batch miracle. I think that solving the pump by increasing flow and adding a recirc tee valve situation will help - I can return excess flow back to the fermenter which will help with stirring when I try something more viscous than birdwatchers. For the parrot I'd love some suggestions.

2) Bottom plate temp fluctuation, mostly due to flow, also stabilized when I elevated the waste hose above the bottom plate, so that it ran in a flooded state. That way the steam was boiling the waste and creating a big boil situation, and that seemed to balance things out. I'll do some plumbing arrangements in 3 below, that will include addressing waste exit elevation.

3) Not enough heat. Even with a 2kw preheater on the boiler refill and 11kw in the main boil, without recycling the waste liquid heat, there's a massive thermal loss there. Also insulating the column will be a big help. The dual exchange at the bottom will cycle water through two horizontal hx's, 2"x36" ss tubes with 3x1/2" copper insides. The waste wash/slurry will go through one counter to cold water, the now hot water will flow counter to the incoming wash/slurry on the second one. I'll hard plumb a tc elevator to bring the waste up above the bottom plate where it enters the horizontal heat exchanger.

4) Low wines exchanger drainage - at the end of the run having a small valve on the middle bottom of the HX would allow me to empty it rather than having to dilute with flushing water or leave low wines in the HX. This is a pretty easy fix, drilling the hole without perforating the inner tubes will be the trickiest part.

That's my main set of pinch points for now. I think that if I insulate, rebuild the parrot situation, build bottoms hx, add the low wines hx drain valve, I'll be able to find a new set of pinch points on the next round.

Pros:

Start up time ~15-20 minutes, shut down time is just flushing the system with a few gallons of water and turning off some switches and valves, maybe 5-10 minutes. Speed is great, I got through three 15-gallon pot still charges in 1/3 the time, 1/2 the power consumption, and way less set up, tear down, and cleaning effort. Plus the low wines are double strength of a typical stripping run. The whole thing was fun. I think the speed is also a con though, I won't get to run this often, but it sure is fun to build, tweak, and run!

Pics:

Injection site on left above topmost plate:

From top to bottom: Thermowell in fluid zone of bottom plate, steam entry, waste exit:

Vapor condenser descending on right, horizontal low wines/wash hx:

Low Wines exit, u-bend to maintain back pressure, parrot. Originally the parrot had an uppermost vent hole, then a thermowell hole (I cork this for running the continuous), then the hydrometer port which at 3/4" is too small and the flow pushes up the hydrometer. Need to rebuild the parrot:

[pope]

LOL Larry it's just been kind of nuts that I actually built this and it works, just a head trip that it really ran well at all.