Distillation Generator

So this thing turns as the water on the bottom of the disc evaporates causing the top of the disc to be heavier?

Yes. Perhaps not all that powerfully, but yes, it is intended to turn. Maybe it only winds up a clock or something.

Yes could we see the animation of the operation....?

No, you may not, since I do not have an animation, and I am not a cartoonist. Use your imagination, and I don't care if I get a C- for a grade on this homework.

Did you make that? Clever!

What is the power source for the evaporation, solar?

Solar illumination, sorry I did not make that more clear. Light shines on the left side, shaded on the right side where the water is added. Could be somewhat focused light, but not necessary, I think.

Seems like it would have to be really huge, like enormous, to get any useful work....Have you considered oxen?

Yeah, but who wants to follow those oxen around and around all day?

It depends on what magnitude classifies as "useful" work. It could be that 10 W is a significant amount of power, such that in one day it might be possible to store as much as 80 W-hr. Surely that will power a few LED lights, and keep a cell phone charged, while potable water is being supplied from a questionable source.

Obviously there would be a real limit to size of this thing, based on the need to tilt the axis, if nothing else. No tilt equates with no driving force for rotation of the disc, and then the distillation would also shut down. I cannot see this thing being more than a few meters in radius. Under the conditions of a 2.5 m radius, with 2/3 open to sunlight, a 45 degree tilt, the surface would be near normal to sunlight only at high latitudes in summer.

13 m² active area (2/3), at 45° off vertical, and say 30° latitude in summer, where the sun is only about 15-20 degrees off vertical, we have cosine(35°) to factor in.

This reduces effective area to approximately 10 m², at about 800-900 W/m² average incident power. I see a thermal power of upwards of 8 kW. That should distill a substantial quantity of water over a solar day. Thus we should harvest about 64 kWhr thermal. 2246 kJ/kg is heat of vaporization at atmospheric pressure. 2246 kJ/L production is not far off. 2246 kJ/8kW gives 281 s/L or about 0.214 L/m production. This amounts to 102.5 L/day. Not bad. I have no idea of the work done by the rotating wheel, obviously a lot less than the mass of water evaporated falling through 5 m.

Sounds like a combination of distillation using a form of the radiometer effect to produce an electric current.

I always wanted to scale one of these up. It runs on water evaporation as well.

Let's get real crazy!

If you can just find a way to connect them all to a single output shaft...................

You might be able to , wait for it,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,........................save the world.

Yeah, then I would show up, stumble, and knock the entire thing over.

My buddy found our IR thermometer probe that the reactor lid sent flying. It was about 25 ft away sitting under a John Deere. Still inside the barn, but I was impressed.

I think this next run, we better turn on the water pump.

To avoid the accident, have a water level alarm.. when it gets too low, have an Arduino or RPi with a WiFi shield or hat send a text to your cell phone. Pretty cheap and easy to do these days.

Or a float switch if there's room?

Right! You can't really have an alarm without a sensor to activate it.

Perfectly viable suggestion, and thanks. Do you have size and part number of the one in the pic? I originally considered this, then thought I needed a tighter control band, but a tight control band does not work with the pump in inhibit mode.

Same web site you suggested, in polypropylene, good to 210 °F, less expensive, can go through reactor side wall, instead of lid dome. 1/2"-20 threads bulkhead. Probably good enough, and far less complicated than load cell arrangement for pump control.

SM-1100-PP horizontal float switch. Good to excellent reliability, I expect.

"Whoever is spared personal pain must feel himself called to help in diminishing the pain of others. We must all carry our share of the misery which lies upon the world." -- Albert Schweitzer

Sorry, I just grabbed an image for illustration and can't find that specific one again.

They're pretty generic.

no problem, I found it in the link to the image.

https://www.amazon.com/Uxcell-Water-Liquid-Stainless-Switch/dp/B006Z968LK

they work well. i use one in a steam genererator

I suppose we could add another shield (Wifi) to the Arduino Mega that is being used for controlling reactor pump, and send text alerts every ten minutes when water level is low and is not reset by pump. Buddy failed to enable the pump switch on reactor stand panel. It is handy to have a pump inhibit switch when setting things up.

Load cell control was set to ±25 g, with enable at -25 (low alarm), and switch off at +25. This represents about 2.5 mm level change in reactor.

I had considered a float switch, and might retro-fit one in as a safety mechanism, as suggested by others in our group, and I see that Lyndoor® Industries has also recommended this practice.

I think it should look like this....

That way even if it doesn't work it'll look damned impressive....!

Certainly, there are no shoestrings in their budget. I might consider something like that for the next gen, submerged arc reactor, but that is still on the drawing board as LER-2. I expect we will forego painting, insulating and sound-proofing and lead lining the interior wall of the barn, and also will leave off the white caps, masks, and Tyvek™ suits.

Right now, LER-2 will be a simple experiment with carbon arc electrodes, and a welder power supply. We will record volts and amps in DC arc mode (I hope), otherwise I will be scratching my noggin about power factor all day. Time to boiling under controlled resistive heating only versus time to boiling with submerged arc.

Didn't a university somewhere come up with something to this effect that relies on bacterial spores that grow when wet, and shrink when dry, to make muscle motion?

Supposedly, that slows down pond or lake water loss, since the entire surface is not able to couple with dry air.

Hint: Sterling engine.

Stirling.

OOps, my bad.

Tomayto - Tomahto

Potayto - Spud

If you mounted a magnet on the top and a magnet on the bottom, and a coil of wire on the top and a coil on the top, would this produce an alternating current ?

In theory yes. Practically however the amplitude and frequency would be likely be somewhat "wild" and need to be synchronised to be useful in any electro-mechanical system.

I think in this case, the solar is not helping the process, rather just functioning as a limit.

Assume best case scenario, that the solar dries the wheel instantly at the bottom of rotation, and that the mister saturates the wheel at the top of rotation, getting none on the dry side. Is that not the case for an ideal water wheel?

Power available will be limited to (density) x (acceleration due gravity) x (flow rate) x (effective difference in height start to finish) x (various real world inefficiencies)...

Flow rate in this case is limited by the evaporation rate. Water has a fairly high specific heat. If you have a perfect solar collector and there is no change in temperature, i.e. the water just goes from liquid to vapor, assuming 1000 watts/meter, for ever meter on the drying side, you could evaporate a gram of water in a little longer than 2.2 seconds.

So if your water tank provides an effective height of 1 meter then for every meter of solar collection area, unless I have miscarried a zero somewhere...

....you are limited to a little less than 1/100th of a watt ( these numbers scale with additional water tank height and with solar collection area, so long as the ability to evaporate water does not outrun the ability to supply that flowrate)....and you still have to use more energy filling the tank than you will get out in return.

.

Far better would be to get cheap solar panels and a battery.

Clearly there are better ways to desalinate and filter and disinfect this water. Media and Carbon filtration followed by membrane capacitive desalinization (tunable) is the lowest specific energy input purification method. Now, if the wheel is arbitrary large, and the solar input is one or more linearly focused bands, of arbitrary power (due to collector field), whether or not the heat is from a resistive heating element under the disk or light and heat focused on the disc, it will work. Light may help sanitize things a bit, if the intensity is high enough (and still not vaporize the disc itself).

Wait, this is for desalination and purification, not as a power source? I guess I was confused.

Well, it has already been poo pooed as not great at either. The initial intention was to have a little of both. I like the idea of sending vapor high aloft, and letting gravity take care of the generation part once condensate is formed.

You could double dip this one and use the mass change in the disc to generate some power and the head developed by the altitude change of the condensate. However, I would use the two mechanical sources to drive a lift pump to get the feed water to the disc or increase condensate discharge pressure to make it an energy neutral water supply.

Something like that, and it might even turn out to be of some use in a nearly water-less place. That way when someone (finally) tells me: " Hie thee to a water-less place", I can fetch my kit and go in confidence.

you also have to take into account the vapor pressure since the atmophere inside the unit will be saturated with steam. this will take even more energy to evaporate.

Perhaps you are right, but some de-coupling of the left from the right is easily possible, merely using a light blocking baffle, and it could be gray to black to prevent condensation from taking place on the right half.

Hopefully, the vapor flow upwards could be aided by some chimney effect, such that condensation would want to induce partial vacuum at the top where the condenser would be (far aloft).

OK, one can get more power out of the water wheel effect, but remember we are in a nearly arid to arid setting in this thought experiment. We do not have an infinite or even extensive source of water to run through.

We are not in Cambodia.

I cannot see why it would turn one way instead of the other. Which makes the rotation unilkely.

However, if you managed to capture the energy from the evaporation, the maximum output power you could get should be less that 30% of the power evaporating water (Carnot machine theoretical efficiency). You can make the numbers with the water output flow.

Finally, this force will need to overcome parasitics. Test parasitics building a homemade mechanism that would make the systems move using gravitational force, by changing the weight until it matches.

Make the numbers and see if your idea is likely to work in theory.

Wet and heavy one half, less wet to dry on the other half. It rotates clockwise.

I suspect that the mechanical output would be 1/3 times 1/3 potential energy (Frictionless, ideal) since the evaporation effect means that almost no water makes it to the bottom of the disk. Only half the water mass makes it half the travel.

I suspect also that the complexity would cause a compromise to both objectives purely through trying to combine them.

There are many simple survival methods to use plastic sheeting as a tunnel with a slight incline. Aus soldiers used same in desert places for potable water. No moving parts, scalable to needed output, easily packed away for re-location.

If you want electrical energy, then why not thermo-electric effect? expensive set-up, but highly reliable. My first discovery was Russian miners using on kerosene lamp chimneys to charge their batteries for work next day.

Everyone is missing that at minimum, 1/3 of the disk on the right side is shaded, and this could be extended to half the disc. Water loading is such that about 5% of the water drips off the bottom edge of disc, while surface tension retains the rest.

Evaporation should be inhibited by humidity build up on right side of disc being dosed with water. Evaporation should be complete within 20% rotation of the exposed side (about 60°). I am sure this will have a role to play in any energy extraction of the rotating disc.

Perhaps a better ploy would be to arbitrarily increase the height of the insulated vapor column, with a flat plate condenser (air-cooled in that case, natural draft) at the top, then let the head height drive a small turbine, when the top reservoir is full.

This thing would be ungainly, but it can still work, and is relatively simple to make.

You could incorporate an absorption system into the mix....maybe you could reduce this to it's simplest form....?

http://www.waterworld.com/articles/wwi/print/volume-28/issue-3/regional-spotlight-latin-america/solar-powered-water-desalination-heats.html

Truly an excellent system they have put forth in Chile! God bless the vintners of Chile!

Reclamation of any part of the Atacama Desert would be a Herculean achievement the like of which has not been seen in recent years, but of which much has been dreamed.

This far surpasses the simple system I has sketched up, and will dance circles around it in terms of output, simply due to focus. Upgrading the energy source to one of higher intensity makes the side processes possible in a major way. Now, they will modularize this so that cookies will be cut, and deserts will bloom.

..."In the HCPVT system, instead of heating a building, the 90° Celsius water will be used to heat salty water that is passed through a porous membrane distillation system where it is vaporized and desalinated. IBM estimates that such a system could provide 30-40 litres of drinkable water per square meter of receiver area per day, while still generating electricity with a more than 25% yield, or two kilowatt hours per day."...

That's pretty impressive results...

Interesting concept in that it captures a hydrologic cycle in a fairly compact space. However, I think that money in versus power out would doom it economically.

Some efficiency might be gained by aligning the axes of the housing, the disk's geometry, and the disk's rotation. (And perhaps by a solar tracking scheme, but that might add too much complexity.)

more efficiency can be gained by running the saline thru a black copper pipe coil before it hits the wheel therefore it will gain heat from the sun for ease in evaporation.

Or just a clock mechanism on the rotating disc, to shift the orientation of the axis to the sun? I don't see the disc spinning more than a few rpm at best.

So what happens to all that salt that is left behind on the wheel? Don’t you think that will impede the process on several fronts?

Yes, it would, one has to have a slip-stream bleeding off the bottom of the wheel constantly, ever so small, since the main feed is also small.

The only way this thing gains any usefulness is if the vapor column were very high (100-200m), and water (as condensate) could be stored on a hill above, but OH SNAP, we are in the middle of a flat, arid landscape.

I guess we better know how to make strong towers, and pipes too.

Reading all the way down thru the comments and finally JS just started to touch the main point in #40.

Any rotating system that is meant to produce power comes down to two things. Torque and RPM (T x RPM = power).

So zooming out and looking at this concept high level the overarching question is: how fast will the widget spin and how hard is it to turn?

If a disk is a slow Turner, then hope it has lots of inertia.

Or if disk is lightweight, it better spin really fast.

Otherwise you won't get any work out of the system regardless of the plethora of nuances on angle, fluid, sun orientation etc. which are effectively just tweaks on efficiency.

This thought experiment is about ready to go back on the "bone pile".

I was thinking large somewhat heavy disc, then the bearings become an issue, perhaps.

Note that the disc is geared up very high by the time we reach the generator/alternator.

Stirling engine is more fun to toy with anyway.

What is chilling the disk?

Evaporation prevents the left side from getting too hot, but I do see the need to cool the transition zone before splashing water to it.

Not every place has a high dew point, or wet bulb point. I suppose one can relay on cooler air in the shady zone to cure the problem once disk drops to the wet bulb temperature rather quickly.

Or maybe it won't work at all, if there is some sort of humidity "lock" in the system, and that results in no transfer of water vapor out of the system.

I see that it might be important to have a minimal amount of air flow, to maintain wet bulb condition on the shaded portion.

It is a good idea but which should be tried out experimentally. Light on one side of the plate will cause heating which will start movement of water molecules in a convection and to me this convection will be too feeble to start the wheel rotating. First where will the forces rotating the wheel originate? I will assume that the rising of the warmed molecules and the replacement from below (a convection) is the source of force and therefor the wheel should constructed like an impact turbine not solid. The second part is about achieving distillation. That means that the water will be raised to 100 degree celcius in the device to make steam. Look at the insulation of the sides of the container to achieve this. A more difficult issue is how to top up cold water to replace the distillate.

If the wheel is suitably large, there is less water on the left (lighted) portion than on the right (shaded) portion where water is being loaded. This results in a moment imbalance, and rotation of the wheel is natural.

Curious about the wheel itself. Is it thick/thin, a plate/drum, mesh/solid ? I am trying to picture the surface area for condensation/evaporation to take place.

....and something I might have missed...what is the prime purpose of this device, where will it be sited - who will use it and operate it - mobile or fixed - and so on ??

• Site - outdoors only
• disc profile is thin compared to diameter by conservation of materials.
• disc is basically a laminated plate, with some type of felt like material on it
• Greater surface area should slightly improve rotation speed, I guess.
• The prime purpose of the device is as a thought experiment on a slow day to be quite honest.
• Secondary purpose would be generate enough electricity out of cheap materials to charge a cell phone, run a light or two (LED), and also keep a radio playing, and at the same time, provide clean safe drinking water.

That's really easy, just use the mass/energy calculation for Horse Power that Watts settled on: 32,572 ft lb/minute. So if you are talking about moving the wheel with water condensate weight, you need to factor how much water you are moving into/out of the wheel and the lift height. So 1 horsepower(745.7 watts in electricity) means moving 32,572 pounds of water one foot in a minute, thats a lot of water to boil! How big is your wheel?

So when you say small generator, how small do you mean? I think that you would need a gigantic system to do any useful work with the condensate. However, if you used the steam.............