Dephlegmators

[Usge]

Thanks Rad...I think you are right! That's what it felt like too. Had the same experience on my boka. Not making anymore mods...before testing with low-wines/wash. I've just got a few leaks to plug up first.

[myles]

I still cant help feeling that a solution to this is not the inputs to the dephlegmator at all, but the outputs.

Because of the pressure differences, the fast flow from the liebig is 'sucking' the contents out of the dephlegmator when they are combined. So don't combine them.

Run a seperate output line from the dephlegmator. Or add in a small chamber in the return path so that the dephlegmator output can drip into the coolant return path. By controlling your output paths you can feed the dephlegmator with full pressure and still have a very slow flow through it.

All my condensers run on a fully pressurised supply with flow control on the outputs. The only time there are problems are when trying to combining the return paths. I now have my low flow rate return paths on individual lines back to the supply tank.

Add in a coil wrapped around a hot vapour path so that the portion of coolant that will eventualy get to the dephlegmator has been preheated, and it might help.

You don't really want all the liebig output to be hot - just the bit that feeds into the dephlegmator.

The alternative is to actually feed your liebig output into a propper header tank remote from the column completely, and run a seperate supply line from the tank to your dephlegmator. Sort of like a charentais still but with the vapour path heating the coolant that is destined for the dephlegmator.

[Usge]

That actually makes sense myles, and it jibes with what little I read about it in terms of commercial operation/design. Some of them apparently use a separate heated water source that is monitored, and pre-heated before going into dephlegm. In that regard, I'm not using a tank for my water source. I'm using a faucet — it does have hot/cold water though. In regards to siphoning out...I'm sure you are right. But, my current mods seem to be working ok in that regard so far. Since cutting down my dephleg to 2x2...here's what I've observed so far:

First, by reducing the condenser size, it heats and cools much faster when the flowrate is changed. This is inherent as there is much less water volume to start with. I re-built the head, and the input is at the bottom...controlled by needle valve coming in, and the output is the top. When there is little flow out the top...it's full, but not pressurized. At faster flow rates..it "is" pressurized. On my test run of this using just 3 gals of 10%....I didn't have any siphoning or other issues in terms of getting or keeping or controlling water flow through the dephelgm. It worked perfectly (ie., I could make very fine adjustments and could see the water stream change coming out the overflow tube). I took the liebig out of the loop entirely to get rid of all the complications that go with it (ie., valves, extra lines etc) and just ran a "T" off my faucet with full flow to both lines. This keeps the feed line going to the needle valve on the bottom of the dephlegm pressurized and ready to go...even for very small adjustments. Any backpressure from the line goes out the other side of the T at the faucet. This still requires some some initial setup in getting flow set, dephlegm full, etc. But, this seems to solve the issue you were talking about..without all the complications. The drawback...is not having heated input from the liebig. But, as you said..there are other ways to accomplish this as well.

As to that point...pre-heated water....what I'm finding so far is that cutting the dephlegm down has made it possible to run more flow and/or cooler water to start with. In fact, as I said...at the very start when the vapor came up to temp under full boil...I had to really flow a LOT of water through it to get it to stop dripping completely. Later..my observations were that it was "very" sensitive. If I made small changes in the needle valve slow..it would send the temp gauge on the water diving or climbing. In that regard...I think Rad is right...that part of that instability was coming from just not having enough alc available in the pot to really stabilize things. So, still more tests to come and I'll certainly be posted results here, but it seems to be heating up/cooling fine now as it is. The bigger question is can I stabilize it? I could get it up to temp easy now....on my last run. But, holding it so the water output temp stabilized was more difficult....possibly as Rad suggested because of the fact that I just wasn't running that much alc.

[Usge]

So, the report:

Just finished a spirit run on low-wines...using the new mods (ie,. cut down sq, 2in, shotgun dephlegm, needle on input, flowing cold water to it).
The therm reading for the output water was handy, and good feedback. It's easy enough to just monitor the speed/flow and abv of distillate to know when you are getting it right...but I thought the readings were very interesting given my preconceived notions going into this that the water needed to be 180F or so for this to work properly. Not the case.

First off, the only rough spot in this is the very beginning...ie. coming up to boil...under high heat...with full pot of alc. The little 2 incher has a tough time knocking that down. I have to "really" turn the wick up, even with the needle valve wide open. I had to reduce the heat to the pot, and increase flow from the source (faucet) dramatically to get it to stop dripping distillate. After getting there, I was able to hold it for about 40 mins.

The dephlegm was very responsive after that. Once I was ready to start taking distillate off...I started by first lowering the waterflow rate from the faucet back down. This got it dripping. I then adjusted the needle valve from there. It took a bit of fiddling...but basically, the distillate starting coming over when the water temp was about 110-120F. The distillate would stream at about 130F at the start. And that number "rose" as the run went on. In other words...the idea that the temp in the dephlegm needs to remain the same...(ie., 180F) is not the case at all. And if you think about the basic theory of alc vs water boiling points...you'll understand why. It rises as the alc is depleted. Therefore..the cooling that is needed will change, and the dephlegm will require increasing temps over the course of the run to keep the flow-rate of distillate the same. You "could" do this with pre-heated water by controlling flow-rate (up to a point), to keep everything within closer tollerances, a more narrow range. But, you'd have to know up front...what temp range you need..and make sure the water is not above that temp, or you are screwed. Throughout the run, increasing water flow would slow distillate flowrate, and also raise abv as expected. (and visa-versa). I tried to keep it right at 90%...and had to make several adjustments along the way.

As far as water temps go, early in the run, 140F water temp, would see the distillate stream. By the middle run, that number was 150F. And later in the run, 160F. I ran between 150-160F most of the run. Only at the end...when I hit the tails wall...did I have to go higher. I think by the time I got to 180F, it was pretty much all tails at that point anyway...so I just turned off the dephlgm and flushed them out. So, at least temp wise...things were very different than I had anticipated. But, it made sense after the fact. Throughout the run, I had flow through the dephlegm. The needle valve indeed was the key to getting a handle on that. However you do it, you just have to keep the water behind it (feeding it), pressurized and ready to go. The only real issue with how it worked was at the very beginning...under full boil when the vapor temp comes up. It took quite a lot to get that knocked completely down. In the end, it was a combination of reducing heat, and adjusting flow..that got things back more in line.

The entire experience left me feeling that perhaps I went to far. If I had it all to do over, maybe I'd make the dephlgm 2.5" instead of 2 (initially it was 3.75"). But, I think at some point it starts to be a catch 22...where the more you fix the part up front..the more fiddly you'll make it on the back end (ie., having to adjust flow down so low that it becomes hard to stabilize). I'll stick with this for now...and just remember to flow LOTS of water through it when it first comes up.

The run stats are posted over in the flute thread (including vapor and water temp readings at each collection point)

That's it for now.

[myles]

The entire experience left me feeling that perhaps I went to far. If I had it all to do over, maybe I'd make the dephlgm 2.5" instead of 2 (initially it was 3.75"). That's it for now.

I think you are wrong. By the sound of it you have this dephlegmator pretty well sorted.

I think on this type of still you really are better off designing to do a specific job. Build your dephlegmator to run the still, and above it mount a second one that you only run when you want 100% reflux. Run the second one at full bore to knock down everything when that is required, and then switch it off and drain it.

[Usge]

Thanks myles. That's a pretty cool idea. Particularly if there was a way to setup a loop from the water routing of the first, to drive the 2nd...by just opening a valve (ie., rather than having to use a separate water source/drain).

[LWTCS]

Yep that was Myles.

[myles]

There is always more than one way of doing things. I know that the industry method is to use warm coolant but I think it has been established now that with appropriate sized condensers and good control of coolant flow rate, then you can manage with cold coolant.

I know that I run all of my condensers on full pressure cold coolant and each one has an independent flow control on its output.

We are trying to do 2 completely different tasks here. One is to provide 100% reflux, and the other is to provide partial reflux. Now I am sure that with good coolant management it is possible but WHY BOTHER. To me it seems logical to design the condenser to do each job properly. Now you can do this with double outlet heights if you feed from the bottom, or you can cascade 2 independent condensers one above the other.

If both are designed to run on cold coolant and are appropriately sized, then there is no reason why they can't have a common supply with a simple inlet valve on the second. I would still have my flow control on the output though.

This is different but simmilar in principle, although it also used power management. This is an earlier incarnation of my VM column


Ignore the secondary condenser and instead notice the two gate valves on the reflux condenser? I used to run this in a way that some folks have disagreed with, but I found it worked for what I wanted at the time.

My controller is calibrated. I had one coolant flow valve preset so that I could equalise the column at a preset power level (700 watts in my case). The other coolant valve was switched off. I would then increase the power slightly and bleed off the heads through the secondary liebig on the air vent. Yes I know the arguments against it but it does work.

Once the heads taste was gone I would open the second coolant valve which would instantly kill the output. Then with boiler power set to optimum, i would reduce the coolant flow, restabilise the column and take off the hearts. I never bothered extracting the tails at all.

Multi tube dephlegmators are very efficient and this probably would not work with them. 2 independent condensers though is a different issue and it is one that I intend to look at further.

[Usge]

myles,
You mean like this? (overall height is 4 inches (2 x 2 x2)

3-way valve would work too...IF you can find the right kind with "T" flow. I've bought several...that claimed to have this flow pattern but were actually "L" patterns.

[LWTCS]

I like that.

[guittarmaster]

That could be pretty cool to see done but i suspect it may be cheaper to go the route i went with the "Y" and separate control valves for the flow rate and duel exhaust out.. just my 2cents thought

GM

[myles]

myles,
You mean like this? (overall height is 4 inches (2 x 2 x2)

DoubleShotgun.jpg

3-way valve would work too...IF you can find the right kind with "T" flow. I've bought several...that claimed to have this flow pattern but were actually "L" patterns.

Very close but I actually was thinking of this



With the coolant this way then when not in use the upper dephlegmator will empty.

[LWTCS]

************************
edit for thoughts

[Usge]

myles,
Maybe a dumb question..or something I'm just not seeing, but afaik, the purpose of using a valve on ouput to the bottom module would be to restrict flow "just enough" to pressurize the bottom and get water to flow into the top module. That way, there would still be flow to the bottom module...and you'd need "just enough" pressure there to get water into the top module for additional cooling area because it would be counterproductive to restrict flow to the bottom more than was needed simply to fill the top. (you'd loose cooling in the bottom to add cooling in the top, instead of multiplying the cooling factor as intended/desired) From there, having the output at the top means...it has to fill first before draining...and would do so regardless of the flow rate coming in. Mine also uses one less valve

In your design... I think you'd need to restrict flow at output on the bottom module a good deal in order to keep enough pressure to push it up to the top. No? From there you'd need to flow even more than the open drain at the bottom before it would start to fill the top module? You'd be trading the cooling at the bottom, for the top. I sort of approached this problem as ...divert only what is necessary, minimal, from the bottom to feed the top so that you gain "overall". (note: I can see however that having it drain completely, would probably make it more responsive once you shut it down...where as mine..watever water was in there, would stay and have to heat up)

Seeing this issue, I thought initially that it might be more efficient...to approach this the other way around...ie., use the top...to fill the bottom. That would have gravity working for us..and not require restricting output flow on one to feed the other (ie., it would allow more flow to both places). ? But was put off from it because it would throw vapor readings off (ie., taking a reading from below the bottom module that was not always in use).

Also to reiterate one could use any sort of condensor design for the auxillary module...ie., use just a jacket (ie., liebig) or even just a coil wrapped around the outside of the tube ..etc. to provide enough extra cooling.

[Usge]

Here's a simpler approach someone had mentioned earlier.
,
When the needle output valve is open..the water drains at that level. If you close that valve, the water then rises to the higher level. When you start with it full (middle valve closed), to run in full reflux. Then, just open the middle valve so it drains from lower...effectively shortening the shotgun.

[Barney Fife]

When you start with it full (middle valve closed), to run in full reflux. Then, just open the middle valve so it drains from lower...effectively shortening the shotgun.

I like this! Sweet and simple.... And, we can add another take-off and valve at the bottom, or a three-way valve at the input, to drain the dephleg when we get into the tails collection, where we simply want to run flat out and collect as quickly as possible.

I senses a modifications coming soons, to me own dephlegs....!

[Usge]

.... And, we can add another take-off and valve at the bottom, or a three-way valve at the input, to drain the dephleg when we get into the tails collection, where we simply want to run flat out and collect as quickly as possible.....!

You can also drain it from the bottom for tails collection without adding another valve by using a one way control needle valve (which is what I have on mine). It controls the flow in one direction only, and has a check valve that allows drain/back flow in the other. So, long as there is pressure on the valve...it only flows in. When you release the pressure on the valve (ie., stop or slow the water flow going to it, the water will drain out. Like you said..a 3 way would work as well.

I got mine here:

http://www.mcmaster.com/#flow-control-n ... es/=d16otv" onclick="window.open(this.href);return false;" rel="nofollow

[myles]

Its funny the way the brain fills in the missing details. There are many ways to solve this cooling issue.

I started from the premiss that the flow rate in the second condenser would be much higher than in the first. I was taking it for granted that the outlet pipes would both be smaller than the inlet ones because I would want the condensers to be pressurised to ensure that they were always full when in use.

When I looked at your diagram I interpreted the valve to be the flow control for the bottom condenser and nothing to do with the top one. I 'visualised' the solution that you were thinking of, to be that you would have the top condenser full of hot water when not in use due to the (not shown) flow control valve on the top output. Open that valve for 100% reflux and the top condenser would purge the hot water and fill with cold. In the process it would also increase the flow rate through the lower condenser.

I pecieved a possible solution to be independent chambers so that the flow rates could be different (permitting a smaller top condenser) and so that the top chamber could be empty when not in use. My mind immediately fitted a float type automatic bleed valve to purge the air out of the top chamber.

Your next illustration with the central drain would work just fine if you would fit your flow control to the input and have the valve shown as an open/ shut type gate. Any attempt to use the indicated valve as a flow control, would result in varying heights of coolant due to changes in back pressure. Also with the valve open you would be at maximum flow rate and as you close the valve to use the top chamber, you would also reduce the flow rate. To me this would be counter intuitive. I would want to do the reverse, increase the flow rate when going for 100% reflux.

[Usge]

Okay, Been a while but thought I'd dig this one back up. I found a bad leak in the top of my shotgun dephlegmator ....that is sealed up. So, I have to tear everything apart to rebuild it again. Thought it might be a good time/chance to revisit some of the things here and maybe pickup some mods and go threw some thoughts.

My goal is:

— to have a dephlegmator that at full tilt..will knock down everything my stove can throw at it. (that's about 1200-1500watts worth of power).
currently it mostly does this...drips a bit at full tilt when running low abv

— that will operate within in regards to vapor/distillate flow within the full range of a new 3-way T port ball valve (ie. not just off-on within the first micro portions of the valve being opened)
currently it does not really do this with the needle valve on the input flowing cold water to it.

I reckon there's some math somewhere that might be a help in finding those parameters? But, those are mainly my goals.

I plan on eliminating the liebig product condenser and replacing it with a shotgun...that will be tied to the dephlegmator via the T port 3 way ball-valve. The shotgun product condenser shall be such a length..that it can a) knock down everything that can be thrown at it (1200-1500watts) while at the same time b) works in concert/harmony with the dephlegmator by feeding it via it's output such that it achieves the above goals. In other words, it needs to keep the dephlegmator happy and operating within the full range of the ball-valve while still knocking down everything that is thrown at it.

Dephlegmator:
As it last stood....my delph was being fed only cold water from separate line. At 3" long, it easily knocked down everything the stove could throw at it (full heat), but was overpowering to the point that even micro adjustments on a needle valve would not control distillate flow. Cut down to 2" it could barley hold it's mud with the stove at full tilt (it would drip a bit), but allowed for more headroom in operation when setting it for the rest of the run. It still only operated within the last bit of the range of the needle valve however (out of 30 clicks...it worked only within the range of the first 10 to set anything but a drip). So, now I have to think about my options here. Obviously, going hotter on my dephleg would mean more operational range for my water flow. But, would be at the expense of full reflux capability. My current design seems to be just a bit off in both areas (how to fix that?).

I've got lots of things to consider here. First..I can keep it the way it is..maybe extend it a fraction. Or, I could widen the holes and go with fewer, larger tubes...in hopes that it would slow down the distillate just a bit? (ie, four 3/8" ID?) Or I could go with different design entirely...ie., original design...ie., a 1" tube about 4-6" long inside reversed internal ftg reducers, etc.? The only thing I'm afraid of there...is starting from scratch...I wouldn't be leveraging at least as far as I've gotten with what I have. Suggestions are welcome. All of the above would be run off the product shotgun condenser output.

I'll reiterate the goal here...I want to be able to put it under full reflux with the T valve set to 100% flow to the delph....then operational range somewhere between 1/4 to 1/2 way (ie., such that it's flowing distillate and still returning/refluxing enough to fill the plates). This coordinated of course with the heat. The way the T valve works is it balances flow between 2 different locations from one source. So, as I shut the side to the delph...it is opening the side for the product condenser output such that they always stay in balance (this as opposed to having 2 different valves to balance). This should help a bit in that under full reflux..since there is nothing hitting the product condenser...the output should be cold/er. The, as you reduce flow to the depleg and vapor starts to hit the product condenser..it should warm up a but..ie., the more that flows, the warmer it will get. This should also help in the other direction. This also negates the need for a manifold, or other complicated water routing.

Having prefaced all that...here's what I have in mind....looking for critique, advice...math, etc. I'm thinking of maybe extending the tubes in the current dephleg design...maybe 1/8 or so (a fraction) in hopes to take care of the drippy distillate at full tilt, and using the output from a 12" long 2" with four or five 3/8 ID tubes shotgun product condenser via a 3-way T flow valve to feed it. Maybe that needs to be shorter..to run higher water temp? Or maybe not...to make sure it can knock everything down (math? opinions?) I have a secondary thermometer that I used to have inline monitoring the dephlegm's exit water output temp. While that was interesting...I'm wondering if perhaps it might be better placed in this new setup...inline to monitor the temp of the water "feeding" the dephleg (iel., the water output of the product condenser's)? What 'ch'all think? From there..I plan on using tri-clamp/ferrules on the bottom of the dephleg head. I'm also replacing the ftg/90 degrees at the top which leaked some..with a one piece full turn unit. I also plan on hard soldering the tubes in the shotgun this time where it's been leaking with 15 silv with copper/phos (no solder) at 1100 degrees (ie., it has to turn "red" before it will even melt). The only problem is..stuff is very hard to flow..it mostly just 'melts' and you scrub it around. But, it won't come unglued when I solder other things around it.

Anyway, thoughts on this would be more than welcome!!!!!

And to myles...I know in another thread you had mentioned was there any constant one could use for approximating correct operational size for a shotgun depleg....and I think that depends on quite a few variables. But, having now rebuilt this thing 3x over...I think its safe to say that it's somwehre around "square" (ie., 4x4, 3x3, 2x2).

U

[myles]

Thanks for the info. On a previous build I tried a variation of a dephlegmator with 7 coils wrapped around the outside of a section of 2" tube. Probably about 3" long by 2" open bore and it certainly did work for partial reflux, with quite good control too. Just a variation of the clasic open bore type deplegmator, but real easy and cheaper to build than using reducing fittings and larger bore tube for the outer shell.



I intend to use something simmilar above my thumper to fill the second chamber that holds 3 bubble caps. As I also wish to achieve 100% reflux - which this can not do on its own - I am going to combine it with a single coil inside the 2". This is selectable and will only be used for when I wish full reflux.

For a bit of variety I am using a single coil - enhanced with a copper plate helix, to spiral the vapour path. Thanks to decoy for the illustration that follows.



Mine isn't that impressive It is just a single coil with stagered 1/2 circle deflectors.



I tried the full disks in a continuous spiral first, but thought the pitch angle was a bit tight on the dry run. They have now been cut into 180 degree sections and will be fitted on alternate coils, overlapped slightly, to provide a more gentle vapour path. The coil was wound on a 1.25" mandrell in 1/4" tube.

I think there is real potential for using 2 condensers. 1 the right size for fine control when used as a dephlegmator, assisted by a secondary for when you wish total reflux. In the shotgun style this could easily be achieved by having 2 output levels to control the effective length of the condenser. Will be interested to hear how you get on.

[The Baker]

First let me say I am not very knowledgable about all this.

But....

If we can take it as a given that the Dephlegmator is of sufficient capacity to do anything wanted of it;
And given a supply of water at a, preferably, constant temperature (so that you did not have to make adjustments):

All you would need to do to lessen the cooling ability of the dephlegmator would be to reduce the flow of water (and thus reduce the cooling effect of the water.).
Perhaps by using a constantly variable pump.
Or more likely with a simple tap before the dephleg. that would bypass an easily controllable amount of the water.
A temperature guage in the main (return) water flow after the dephleg. could be useful.

Particularly for an existing set-up this should be cheap
(cost almost nothing, maybe even a plastic garden tap and some plastic tube or garden hose....)
and would save you having to re-arrange the copper-work!

[LWTCS]

All you would need to do to lessen the cooling ability of the dephlegmator would be to reduce the flow of water (and thus reduce the cooling effect of the water.).
Perhaps by using a constantly variable pump.
Or more likely with a simple tap before the dephleg. that would bypass an easily controllable amount of the water.

My feelings also...But certainly there is more than one way to skin the cat

[Usge]

Yes, what you say makes sense....I've already tried it. There is a needle valve on the input which controls the rate of water that goes through it, as well as a Y valve on the faucet for it's own flow adjustment up to the needle valve. The 3" delph would only start dripping distillate if you turned the water "off". The 2" version would allow a very, very tiny bit of water flow through the delph to maintain sort of a dribble/stream rate. The needle valve goes from 0-9...4x around (4 rings). I had it on 5 of the first rung. So, there was only a tiny, tiny trickle of water going through it. That tiny of a flow rate of water is near impossible to maintain. I need a little wider operating range here....a little more flow of water going through for the same amount of reflux. And I need slightly more (very slightly) knock down on the top.

The Y valve on the sink also could be controlled...to vary waterflow. It was not running off the product condensor. For the first part of the run...I had to turn the water up all the way...and it still dripped through just a bit on highest heat levels. After that...I turned the water level from the sink down..fiddled with the "Y" valve until I had enough flow to the product condenser...and then used the needle valve on the delph for it's input. As I said...at that range/heat, etc., I was using only the very first opening portion of the needle valve . The water pressure would vary from faucet..and occasionally stop (siphoned out the other side of the "Y" becuase the flow from that side was much greater going to the product liebig). Lots and lots and lots of fiddling.

What I'd "like" to have...is everything working "together"....ie., the output flow of water from the product condenser shotgun...is just right amount that the 3 way T valve will operate within its full range of motion to control the delph. ie...all the way open...full reflux. Somewhere between 1/4 and 1/2 setting...being a full product flow rate with enough reflux to keep the plates full. Increasing the waterflow from the facuet to the product condenser for more overall flow is always an option. But, I would imagine there might be a way to figure this out up front so that everything works together. Right now...I've got the worst of both worlds....not quite enough knockdown power for full reflux...and too much for general running/operation of the dephleg...such that only a tiny fraction of water ...which is difficult to control..is used. It's better than the first round for sure. But, its still not right.

As far as taking it down....I've got to take it completely apart anyway to get to the leak to fix it. Nows the time to think about it.

[Usge]

All you would need to do to lessen the cooling ability of the dephlegmator would be to reduce the flow of water (and thus reduce the cooling effect of the water.).
Perhaps by using a constantly variable pump.
Or more likely with a simple tap before the dephleg. that would bypass an easily controllable amount of the water.

My feelings also...But certainly there is more than one way to skin the cat

My main problem is that the current design delph running off a variable water supply already requires to slow/low a flow of water in it's operational range for reliably taking product off and maintaining reflux level...why would I want to lesson it even more? I think my delph still needs to be tuned down a bit for that part of the run....using more water flow to maintain pressure. This issue is counter to the first issue which is....its already cut down to the point that it will barely knock down all the heat. So, if I go much /any shorter...I'm going to be giving up full reflux capability at max flow of water. So, the only thing I could think of...was to break it into 2 stages somehow...or run colder water up front...and warmer water later. Connecting it to the product condenser output seemed logical in that regard...given it would operate this way. ie., in the beginning under full reflux...no vapor would be reaching the product condesner to the water output would be cold coming from the faucet. As it started to take vapor/product off...the product condenser would warm the water and would help with the problem of flow rate at that point.

Possibly...I'll just end up with an even more complicated mess that leaks and doesn't work..and end up scrapping the whole thing for a coil. I guess I'm mainly not understanding why this seems to work fine for the other flutes, without issues of operational range that I know of. Most of them seem to run the ball valves full for full reflux...and about 1/4 or so...to take product off in a stream while still filling the plates. Obviously, 2" doesn't have the same overall volume..but I'm not seeing the reason this can't be scaled down. Missing something somewhere. Maybe few tubes in the shotgun? Or bigger ones? Or ? so its not so sensitive at lower water flow rates.

[myles]

Selectable supplies would work. How about this.



Put a small header tank on your product condenser output, with an overflow to your drain or supply tank to maintain a warm water source. Use that to feed the dephlegmator during normal opperation. A warm supply will give you more control at low flow rates and the gravity feed should provide enough pressure.

For full reflux turn off the warm feed and switch on full pressure cold from your main water supply.

[Usge]

myles, if you are running your dephleg off of your condenser output...it does this automatically. Under full reflux none of the hot vapor is making it to the product condenser...therefore..the water in the product condenser is cool (from tap). When there is vapor reaching the product condenser (less than full reflux), the water in the product condenser begins to heatup. Put it back under full reflux...and the water begins to cool again. It's not as instant as what you laid out, but it does work that way.

[myles]

True Usge, the advantage of the way shown is that when you are taking product, you get a reduced pressure supply to your dephlegmator in comparison to your product condenser. You can run your product condenser at any flow rate you like as the surplus just overflows from the header tank. Reducing the pressure to the dephlegmator will give you a bit more controlability of your dephlegmator temperature. Whether or not you need the control is a whole different issue, and that depends on the individual setups.

My understanding is that these condensers can be TOO efficient. The warm supply and low flow rates that are often reccomended, seem to be just 1 energy efficient mechanism for reducing their thermal efficiency and increasing the level of control. I am sure there are many other alternatives.

[Usge]

Thanks myles. As to control....using OD's latest build as a guide...the 3 way T flow valve...does exactly what you say. It allows different flow/proportions to be attained and balanced automatically between the dephlegmator and the product condenser because it's a "thru" type flow pattern (ie., reducing one side..increases flow on the other). The normal "L" type valves..are imply diverters that are on/off to one side or the other. These are different. It took me a while to find one, and they aren't exactly cheap (even in brass). But, it beats having to use a manifold and controlling 2 separate valves.

So using those mods...product output condenser feeding dephlegm, T flow valves to balance flow, I would have all of those attributes. I would have colder water temps under full reflux and warmer water temps under partial. I would have a way to balance/split the flow between the 2 as needed. The question really is....should I redesign my 2" shotgun or not? given it's current performance. I think most are leaning towards "no". If I make it any less capable...it would make it even harder to reach full reflux. If I make it any more capable..its only going to make the other side of the problem worse, it would most likely mitigate any gains I'd make by using warm/cold water etc. The only other thing I can think that might address both issues would be making it 3" long, with the second, valve switched output drain at 1.5" (1/2 way). This would, at least in theory/thinking, seem to address both sides of the issue...although adding the complication of yet another valve/switch to control. You run it up full for full reflux...then open the middle drain...to lower the water level in it. From there, the T flow 3 way takes over and you have more water flow overhead for any given distillate flow rate. That's the theory. Maybe I can mock something up to test it. Guess it's off to hack and chop and solder . That seems to be the only way to learn things anyway. I'll be back after I build it out and test it.

[emptyglass]

Guess it's off to hack and chop and solder . That seems to be the only way to learn things anyway. I'll be back after I build it out and test it.

I aplaude your efforts mate.

It's guys like you who make it easy for guys like me.

I wish you and your still yin and yang. I just hope you crack the conbination before I lock in my mistakes with copper and solder.

You gave me an epiphony (or just hit me with a 'piffer tree ). Or did I just have one,,,I'm not sure.
The penny dropped on the "full reflux-no heat for condensor" thing.

As to control....using OD's latest build as a guide...the 3 way T flow valve...does exactly what you say.

Always trust content from OD.

[Usge]

After quite a few setbacks, I finally got the next revision of this done. The shotgun condensers were a BITCH to seal up, but I think I finally have it licked. My hat tip here goes to OD, who's design for the Flute MkII inspired this...and the use of the "T" valve. And to all others who's advice along the way helped me get through all the hurdles to fit the various parts and bits. Special HT to Kentucky Shinner who I sourced the ferrules from and the method for getting them installed.

Starting from the ground up, the entire assembly now attaches via ferrule/tri-clamp so it can be used on top of any 2" tube (also with ferrule fitting). All of the external 1/4" nipples/attachments are hard soldered on. The tubes for all shotguns were also hard soldered into their respective plates. HOwever, once installed, I could never get the piece hot enough to hard solder the plates inside the tube. So, they are soft soldered (hence the problem with it continually coming unglued/leaking while adding the fittings, etc). If I had it to do over there, I would have left more room above and below each shotgun unit to allow for soft soldering the fittings on each end without affecting the integrity of the shotguns when using soft solder. Using water didn't work (the solder melted and started to pull away from the edges). The ferrule was, by comparison, a breeze (thanks again to KS)

The valve setup works perfectly!! and seems adjustable in a more stable way...and has very.short distance between everything. I had to sit and look at it a while before I finally came up with this design for attaching it. I call it the "spider"...(although it does not have 8 legs, it sort of reminded me of one). My thought was how to attach this the most direct way, without a lot of extraneous tubing, manifolds, etc. Again, OD's new design was inspiration for this. So, I soldered one leg directly to the product condenser output, the other side to the input of the dephlegmator on the bottom, and the middle/3rd is to drain. Running water through the condenser...with the handle straight up/down, the water from the condenser goes straight to drain. The more you turn the handle towards the dephlemator...the more water is diverted from the drain side to the dephelgmator. It maintains the entire flow/balance the whole time so there are never any pressure issues and the short distance between everything should help with residual lag when making changes.

After thinking about it a bit..I moved the water input source for the delph and the therm that used to be on the output of the dephlemator to the output of the condenser. This allows temp adjustments of the water going in. As well, when under full reflux, there is no vapor going to the product condenser so the water coming out is cool (same as source). The therm there makes it possible to monitor the water temp and what's going on inside the product condenser before it feed the delph. This should make it easier to dial in the overall water flow setting for optimal operation/results in terms of both delph operation and reflux . Monitoring abv/distillate flow rate from there should give me all the feed back I need. That's the theory anyway . Speaking of which, after much thought, I left the delphegmator at 2" (square) so I could at least know start from where I left off with my last experiment/build.

The deplegmator drains from the top...but I moved the actual output for that below the level of the input. (see the back image). I've yet to test run this other than checking it for water leaks, and fitting. So, we'll still have to see how things go from here. I'm hoping for at least some improvement in basic operation...such that it doesn't require a lot of fiddling. So far it looks promising! The product condenser is five 3/8" tubes inside 2" jacket. This will reduce to a 1/2" coupling/union for output tube to the parrot.

Here's a few pics....(not cleaned up or polished yet):