Condenser control still

[Popcorn Fan]

I have one of these in 2 inch, I think people are over thinking it. It is very easy to move it by hand, it only takes 2 seconds to move it.

[Azframer]

I read this whole thread and I noticed you where thinking of how to get clearance for coil to allow product to get to take-off. I think you need to solder 2 wires to the coil not to pipe (to hard to do). Place them far enough apart so they will elevate and be to the side of take-off hole. They will allow easier sliding most likely. New to this but it is what I see.
Edit = use 12 gauge wire.

[MuleKicker]

Manu is a respected builder. He has video of this model in action. It works fine from what I can see.

[Azframer]

Manu is a respected builder. He has video of this model in action. It works fine from what I can see.

MK I know that, he didn't sound like he was totally pleased with the solution to the problem. I am no means trying to say he is not a great builder don't get me wrong. Please don't take it wrong.

[manu de hanoi]

I read this whole thread and I noticed you where thinking of how to get clearance for coil to allow product to get to take-off. I think you need to solder 2 wires to the coil not to pipe (to hard to do). Place them far enough apart so they will elevate and be to the side of take-off hole. They will allow easier sliding most likely. New to this but it is what I see.
Edit = use 12 gauge wire.

2 rails is a good idea

[Azframer]

I read this whole thread and I noticed you where thinking of how to get clearance for coil to allow product to get to take-off. I think you need to solder 2 wires to the coil not to pipe (to hard to do). Place them far enough apart so they will elevate and be to the side of take-off hole. They will allow easier sliding most likely. New to this but it is what I see.
Edit = use 12 gauge wire.

2 rails is a good idea

Thanks man that meens a lot coming from you.

[The Baker]

Well, not much less simple...(than the rail).

I was thinking that you could have a sort of extendable tube, with the condenser in the extending part....

Should be neat and with some overlap the extending part would need no other support.

Just an idea I had, I won't be offended if no-one likes it...

[Yunus]

Got a photo?

Sure do. Only change I am going to make is to insulate the column all the way to the take out port. When the wind picked up the flow decreased, I think insulation will stop that.

[manu de hanoi]

The control on this still isnt too great for now, prolly because too much condensation occurs at the tip of the coil and too little at the bottom. The result is that a small change in the coil position gives a big change in distillate output. Control was more satisfying with the 3" prototype. I think I know too little about the repartition of the quantity of heat exchanging along the coil. I don't quite know yet how to make a coil that would condense less on the tip and more near the water output/input. Suggestions are welcome

[LWTCS]

Cold fingers are less efficiant,,,,but maybe a tear drop or wedge shape so that more surface area is closer to the front. Maybe an expansion chamber to slow vapor might mitigate the less efficiant cold finger????????

[Azframer]

Reverse the coil turn it around cut the in and out lines off solder some 180 turns on so your in and out runs through the center of the coil. You will have better coolant towards the bottom. Right?

[Popcorn Fan]

Manu,

I copied your design as soon as you posted it and have been running it for quite a few runs now, it is in 2 inch stainless.

One thing I have found to overcome the problem is to put less water through the condensor, it makes the output warmer but it does give you more range of adjustment. I have no problem pulling 95% over a wood fire although I normally go for 93% as it's a hell of a lot faster.

One thing I was thinking about was a stainless coil, it would be a lot less efficient than copper but here annealed stainless 1/4 is $6.00 a meter.

For me though I think I'll stick with what i have got, if I want I can pull 95% all day so for me why spend extra cash to do something that won't improve quality? A stainless coil may make it a little easier to adjust but for me personally it's not worth the mucking around.

For you though being into design and stuff it might be worth playing with. Same with the adjustment of the condensor, for me moving it by hand is not a problem but I have seen a lot of people talking about lots of modifications.

I think what you have come up with so far is a great design that works really well. Personally I think it is the best design I have ever come across for simplicity of design and effectiveness.

[Popcorn Fan]

Yunus,

Nearly forgot, nice looking still

She'll last you a lifetime

[HookLine]

I think the answer is mostly in the spacing between the individual coils.

At the tip end (the end the vapour first hits) start with maybe 25-30 mm spacing between the coils, then gradually reduce that distance to normal spacing (3-4 mm) for the last 50-75 mm of the condenser.

Also, reversing the direction of coolant flow from normal, so coolant goes in the top end and out the tip end, will give a more gradual thermal gradient along the condenser.

Something like this:

Condenser for Manu CM Still.gif (4.21 KiB) Viewed 3297 times

[manu de hanoi]

Thanks hook, the inflow being where you draw it certainly helps, however spacing the coils wouldnt help because the quality of control depends on the number of coils per distance (each coil is like one product output speed ), so longer and more distant coil would actually degrade control, for the same resolution(=n coils) we'd have more tubing.

I think we have to play on the loop diameter or perhaps tube diameter

[Manback]

I think Hook is right about spacing manu - greater spacing would result in the same size condenser taking greater length.. and therefore coarser control of the reflux..

[manu de hanoi]

I think Hook is right about spacing manu - greater spacing would result in the same size condenser taking greater length.. and therefore coarser control of the reflux..

no no, the condensate runs down along the loops, you're adding distance but make each step bigger. Better control requires distance, but also more and smaller steps

[Manback]

Yup but that would resolve the problem. Think of it this way.

With loops close together, a small adjustment (lets say 1cm) would result in maybe 5" of extra coil being in the take-off area.

With a more spaced configuration, a 1cm adjustment might only put half that much condenser in the take-off area.


No?

[manu de hanoi]

Yup but that would resolve the problem. Think of it this way.

With loops close together, a small adjustment (lets say 1cm) would result in maybe 5" of extra coil being in the take-off area.

With a more spaced configuration, a 1cm adjustment might only put half that much condenser in the take-off area.


No?

no, because the output doent change, which is ultimately what we care about. imagine you have a bad picture with big pixels, enlarging the picture wont improve the quality

[Yunus]

Manu, Are you saying that a reduced surface area per length is the key to more fine control? If so what about something like this.


It would have the normal coil that covers the entire tube to prevent vapor from getting to the atmosphere but have the uncoiled part might provide finer control. Some vapor would always get past the uncoiled part but some would not.

Just tossing out an idea here, I really don't understand the science of it well enough.

[manu de hanoi]

Manu, Are you saying that a reduced surface area per length is the key to more fine control? .

reduced surface per loop is. If you look at your drawing, because the glove of the condenser is on a slope, all the condensate on the tip would fall as reflux until the 1st loop, so you wouldnt get more control.

[Popcorn Fan]

Now I am getting confused.......

[HookLine]

Understand what you are saying, Manu, and you may be right. Have you experimented with a widely spaced coil?

Also, not sure I got the coolant flow direction right in the drawing. The important point is just that it is worth swapping the direction of coolant flow to see if that helps at all.

[MuleKicker]

im thinking this is happening, cause the vapor front hits the tip of the coil first. right? could you use some kind of difuser to "spread" the vapor out? This doesnt sound right out loud... I have a thought in my head that I cant get out right.
yeah, a wider spaced coil may deffinately help. Maybe wider spaced at the tip, and as you get closer to the other end, wind the coils closer together?

[squidd]

Manu, Are you saying that a reduced surface area per length is the key to more fine control? .

reduced surface per loop is

So maybe wind the coil on a conical form, so that it is tapered ?
Like a fir tree lying on its side.

squidd

[manu de hanoi]

Understand what you are saying, Manu, and you may be right. Have you experimented with a widely spaced coil?

havent , i'd be more inclined to try 4mm tubing, or wrapping the first few loops with a strip of copper foil (or aluminium) to make it less heat conductive

[Yunus]

What about a Stainless steel condenser. Yes it would be less efficient but that is the point is it not?

Trying to find the happy medium so that it's efficient enough but not so efficient that we lack control.

So basically Manu designed a still that is TOO efficient

[HookLine]

havent

easy experiment to run

doing the coil in stainless is a good idea too

not sure 4 mm will be less efficient, probably be more efficient, thinner tube walls, more perimeter (heat exchange surface) per CSA (coolant volume), but will have lower maximum coolant flow rate

a conical wind is an interesting possibility, maybe combined with some stretching out for the first half or so

Trying to find the happy medium so that it's efficient enough but not so efficient that we lack control.

that's it...

[manu de hanoi]

more perimeter (heat exchange surface) per CSA (coolant volume)

on the other hand bigger tubing means more total heat exchange surface...If we consider that a part of the condenser is not used (otherwise the output would be better distributed along the length of the condenser), that leaves us room to shrink the total surface of the condenser. Can be done the loop diameter way, the insulation way (aluminium foil, tubing thickness) or tubing diameter way.
-loop diameter way: yes a conical (hard to do) or a smaller diameter for the few loops at the tip
-insulation: the quick and dirty way, some tests would bring useful answers
-tubing diameter: not a sure shot

[squidd]

more perimeter (heat exchange surface) per CSA (coolant volume)

-loop diameter way: yes a conical (hard to do) or a smaller diameter for the few loops at the tip

Smaller D for a few loops at the tip:
Essentially a two step control, Lo and Hi.
Also reduced coolant flow or increased back pressure.

Conical:
Progressive control throughout. Proper taper ratio would need to be established.
Not sure why it would be hard to wind - turn a tapered wood form on a lathe.

squidd