Microwave Still?

triggernum5 · Post by **triggernum5** » Sat Apr 21, 2007 10:48 am

I've got what I need to rig up anywhere from 1-4kW microwave heating capacity, AND THE KNOWLEGE NEEDED TO DO IT PROPERLY!! I figure its the best idea for a burn-free element, and was wondering if anybody wanted to set me straight before I put quite a bit of effort into the build.. I don't see any dilemmas attached, but its a relatively new idea..
Note: This has nothing to do with standard microwave ovens, I'm not quite that retarded..

bushido · Post by **bushido** » Sat Apr 21, 2007 12:42 pm

Very interesting Trigg, never even gave this any thought before. How/what are you using as an emitter? How are you going to avoid cycling, you cannot just emit at 100%. I would like to hear more details, I find this very interesting. I have to give it some thought before I ask stupid questions

I will follow your thread closely and see what I can figure out. I am electronic tech by trade. This will be enticing!

triggernum5 · Post by **triggernum5** » Sat Apr 21, 2007 3:09 pm

I find this very interesting. I have to give it some thought before I ask stupid questions

I too have to give it more thought before I answer stupidly.. I have a few options.. I'm a physics guy, so I've been collecting for a long time.. I have more than a few magnetrons, transformers, bigass caps etc kicking around.. I also have a few wads or 2% thoriated tungsten, access to high vacuum LOW temperature conditions, but Beryllium I'd have to harvest somewhere.. My only reason to go the DIY magnetron route though would be to jack up to ~10GHz optimization, but its not really feasible to expect results even as good as the standard @2.4GHx.. I kinda lied when I said this had nothing to do with microwave ovens.. I meant I wasn't about to be a crackhead that just busts the doors off..

The salvaged magnetrons seemed like a prettier idea when you mentioned cycling.. With 2 - 6 @ 700-1500 watts each I could cycle without a problem, but I'll need to find a pretty remarkable way to isolate the fields if I intend to run more than 1 at a time.. 2 seems doable..
I've blown up more than my share of microwaves, but nothing EM related even came close to the shear destructive power of a bottle of champagne inside one.. That blew the unit into itty bitty pieces of schrappnel.. Its a good thing I 'realized' a small danger was present, because if not for precautions based on that, I'd be dead via the HUGE danger that actually was present..

bushido · Post by **bushido** » Sat Apr 21, 2007 5:39 pm

are you on a 50 or 60 MHz cycle in your area (north america or overseas?)?
I could see 2 emitters working in conjunction with a micro-processor controller quite easily. You would have to measure start up and run down time of each emitter so they do not over power your circuit (thinking cheap here) as one cycles down and the other up simultaneously.
The other problem, though not a large one, would be the ability to hold the temp constant at certain ranges, eg., 170* for meth perk, though I could see using a cycle program to get around this.
Though my trade is ET, I do not do it for a living, so though I may be able to flow chart and design, some of my knowledge will be out of date. I will try to contribute where I can Trigg.
I can't believe you would nuke a bottle of bubbly. I hope it was at least spumante

Avatar · Post by **Avatar** » Sat Apr 21, 2007 6:21 pm

What about using an induction element instead of the magnetron?
It would have to be safer than microwaves which could turn your gonads into stop-nads and/or fry your eyeballs.

triggernum5 · Post by **triggernum5** » Sat Apr 21, 2007 7:05 pm

Bushido, you and I are totally on the same page.. I'm experienced in control programming etc, and figured that would be part no matter what I did.. I'm on 60Hz (Well, 59.75).. As far a draw ups go, I'm proficient enough unless you come up with a concept that eludes me.. I'm not planning on using much post WWII technology anyways either..

Another swet point I can mention is the fact that I have more than 10kW at my disposal 120/220V both going into that area without even re-wiring.. Geez, since I've been thinking about this, I've even been thinking about adaptaion to home heating for Pete's sake..
Avatar, why you gotta be that guy who points out the simpler likely more effective solution when I'm thinking along the lines of "If I cuold just perfect my anti-matter containment, then I could ditch that boring old nuclear idea..":) <JK>

Edit BTW, in response to Avatar's point about safety, I have to take this oportunity to stress something he probably already knows since he pointed out the eye danger.. And that is MICROWAVES ARE NOT RADIOACTIVE, AND THE TERM RADIATION IS DISTORTED IN INTERPRETATION, They are simply LOWER energy light waves in between IR heat and radiowaves.. Most molecules just really like to boogey under microwave radiation due to resonance (Like pushing a bus-stop sign back/forth, timing is everything).. A standing-wave radio antenna of equal power will actually melt ice faster, cause its funny funny stuff.. (Thats why I wanted to jump up to the 10GHz range).. Your eyes are very vulnerable to microwaves.. The nads might be too I suppose since they dangle for purposes of lower temperature.. Also, THEY DO NOT COOK FROM INSIDE OUT.. I realize that is obvious to most ppl, but it baffles me how many ppl are followers of this plain sight faulty logic

nanosleep · Post by **nanosleep** » Sat Apr 21, 2007 9:38 pm

How are you planning to couple the microwaves into the boiler? Waveguide? How are you controlling the SWR in the waveguide? Whats your generation device? How much reflected power can you have before your generation device goes *poof*? How do you impedence match the waveguide to the boiler? Do you worry about various resonant modes in the boiler? How do you shield your boiler to avoid 'leaking' signal? How do you protect your against vapor moving up the waveguild and condensing in your generation device? I'm assuming your generation device requires a few thousand volts. How do you do this safely?

How much waste heat are you producing to generate the microwaves? How much of this waste heat cannot be delivered to the boiler? How much usable heat via microwaves are you putting into the boiler? You may find out that only a small fraction of your input power is getting converted to microwaves.

Yes it's a cool idea, but I think a simple heating element will be much more efficient and definitely cheaper! What benefits do microwaves provide?

triggernum5 · Post by **triggernum5** » Sat Apr 21, 2007 11:32 pm

http://www.invention.net/nadolski.htm" onclick="window.open(this.href);return false;" rel="nofollow
My general goal would be to end up with a modified version of this I found a few days ago.. I don't have any answers to your questions yet, its still in the infancy of brainstorming but I figure with a few rolls of duct tape and my Red Green style ingenuity, I'll be able to get something solid enough in theory that I won't even need to test anything along the way before I fire it up in the dynamite shed behind the orphanage that the nuns run..

<JK>
I realize the idea could go 'poof' as quickly as my home and/or life if I hit a barrier, but as I see it, even if I come to that barrier late in the game I'll still have the makings of the biggest ray-gun I've ever built..

Avatar · Post by **Avatar** » Sun Apr 22, 2007 1:09 am

And if it doesn't work out, you will have the makings for THE BIGGEST MICROWAVE CANNON IN THE WOOOORRRRLLLLD.

Oh yeah...

possum · Post by **possum** » Sun Apr 22, 2007 8:36 am

Bear with me if this seems stupid.
microwaves of a certian frequency/wave length can excite and heat water.

What about pure ethanol.
Some plastic containers are not heated at all, or are barely influenced in my Microwave oven.

I dont have the refrence materials on me, but might (various)alcohols or water absorb/ be thermally excited with certian wavelengths ? I'm not trying to get into Quantum physics/Quantum Physical chemistry here, but it might apply...I just hopr it is nearly an inconsequential consideration...But I don't know..
It is worth pondering a bit

triggernum5 · Post by **triggernum5** » Sun Apr 22, 2007 9:37 am

Nope, not the biggest in the world.. One guy who I believe graduated last year apparently rigged up 40kW, and accidentally fried everything on his boat.. I know he put alot of thought into it, so even if the story was BS I still gotta aplaud him..
Possum you are right ETOH has more degrees of freedom than H20 though, so without even tuning it into some crazy freq. that could possibly bust the azeotropic barrier (didn't think about that before I typed it btw) it should perform better than blackbody heat.. Here is a basic absorbstion diagram.. Granted it isn't in the realm of my wavelength (That would be normal IR heat if I'm not mistaken), but it shows how a molecule reacts to energy (And how much energy is typically reflected!).. The water will transfer energy to the ETOH even if the MW's don't harmonize well at all (which I'm optimistic about)..

masonjar · Post by **masonjar** » Tue May 01, 2007 5:22 am

Microwaves do not heat water because of resonance. This is a scientific myth.

Post by **schnell** » Tue May 01, 2007 8:02 am

that was an ir absorbtion spectrum above, which corresponds to vibrational modes.

i believe the microwave frequencies excite electron energy level transitions.

triggernum5 · Post by **triggernum5** » Tue May 01, 2007 9:53 am

True, 2.45GHz is well below the resonant frequency of water vapour, (and liquid water has no resonant frequency.. Liquids have a broad absorbtion spectrum though, so lotsa frequencies jostle them..
(Actually, if MW's were tuned to the resonant frequency of water vapour then all the energy would act at the very surface, and probably char your food.. Higher than 2.45GHz would be preferrable for liquids though given their viscosity/convection..
Problem I'm facing is suitable waveguide.. I thought what I had could work, and maybe it can, but I'd be a wee bit uncomfortable about it to say the least.. Waveguide ain't cheap (if you can even get a dealer to quote it), and making your own for a sustained operation would probably be questioned by a tazmanian devil whacked on PCP..
I'm really hoping somebody has ideas on sources

masonjar · Post by **masonjar** » Tue May 01, 2007 11:54 am

I'm not so sure that impedance matching matters much in this case. Look at the microwave oven - the load is different every time you turn it on because you put a different object in there. Microwaves with a turntable are constantly changing their impedance as observed by the output of the waveguide. Therefore, there will always be standing waves in a microwave, you just can't allow them to become so intense that arching will occur. This is why you're always supposed to put a glass of water in the microwave when cooking something small - to lower the impedance of the load and absorb some of the microwave energy. In the case of a still there will always be a very large glass of water in the chamber. As for matching the impedance of the waveguide to the magnetron, it's a little bit more important, but on a microwave oven this is already done for you. Besides there will always be standing waves inside this waveguide anyway since magnetrons are not very accurate and produce other microwaves besides just 2.45 GHz and the reflections from the oven chamber are going to travel back into the magnetron anyway. The key is to not let the standing waves anywhere in the system build up to the point that the electric field can ionize the air. The microwave heating system is pretty crude and forgiving compared to a radio transmitter and antenna system where the transistors in the output stage will fry due to the slightest overvoltage or overcurrent. A magnetron is a chunk of metal and isn't nearly as sensitive.

I'm also curious about how you will shield the system. Stainless steel is not a very good conductor and copper is rather expensive. You will have to contain the entire system with at least a conducting mesh that has no hole with a diameter (or circumference?) larger than the wavelength you produce, otherwise you will have microwave leaks. You may want to rent or borrow a spectrum analyzer to make sure you have it sealed up well. As for vapors getting into the magnetron - I'd try to avoid that and isolate it from the vapors with some glass or something - but make sure the glass won't absorb more energy than it can dissipate.

I wouldn't worry too much about energy waste since no still is anywhere close to a model of energy efficiency anyway. And yes, all this work is probably not worth it when a 1kW heater element only costs $10-$15.

hornedrhodent · Post by **hornedrhodent** » Fri May 04, 2007 4:15 am

masonjar wrote: And yes, all this work is probably not worth it when a 1kW heater element only costs $10-$15.

How many dollars is FUN worth?

masonjar · Post by **masonjar** » Fri May 04, 2007 9:57 pm

Fun is worth $33.17US.

Point taken. It wasn't my intention to discourage. This project isn't exactly for the faint of heart though, considering the high voltage and the risk of microwave leaks. I do think it's a neat idea, and most of my post was trying to suggest that the impedance matching probably isn't as critical as nanosleep alluded.

I've thought about alternative distilling methods myself - like applying a vacuum pump directly to the mouth of a carboy without applying any heat at all. When the pressure falls below a certain point it should start boiling at room temperature. Then on the other side of the pump the vapor should condense again after returning to standard pressure. I haven't looked into it any further than just the thought though.

hornedrhodent · Post by **hornedrhodent** » Sat May 05, 2007 3:21 am

masonjar wrote:Fun is worth $33.17US.

I've thought about alternative distilling methods myself - like applying a vacuum pump directly to the mouth of a carboy without applying any heat at all. When the pressure falls below a certain point it should start boiling at room temperature. Then on the other side of the pump the vapor should condense again after returning to standard pressure. I haven't looked into it any further than just the thought though.

Try putting the condense inside the boiler so that the heat is reused. I like the idea but getting a vacuum pump which doesn't add any nasties to the distillate or fail due to being lubricated with ethanol could be a problem!

triggernum5 · Post by **triggernum5** » Sat May 05, 2007 1:00 pm

The one thing I wasn'y sure about was the waveguide I'd need to locate the power electronics safely, and actually contain the energy without idiot jimmy-rigs.. Looking into it a bit, its not seeming feasible.. I was hoping to come up with something with extreme minimal scorching.. Nobody can deny that a soup bowl from a microwave is less likely to have burn on the bottom than a pot on the stove..

MikeyT · Post by **MikeyT** » Sun May 06, 2007 6:19 am

[quote="schnell"]that was an ir absorbtion spectrum above, which corresponds to vibrational modes.

Household microwave ovens are tuned to the resonant frequency of the water molecule. i.e.- the wavelength of one cycle will be on the order of the diameter of a water molecule. This causes the waves to be 'trapped' inside of a molecule and bounce around which raised the electrons of the molecule to a higher energy state. Higher electron energy state = higher temperature.

triggernum5 · Post by **triggernum5** » Sun May 06, 2007 7:51 am

No, nicrowaves are not tuned to the resonant frequency of water.. Water doesn't have a resonant frequency.. This sums it up pretty well:
Q: Aren't these ovens tuned to a special frequency so they only heat water?

A: No. The usual operating frequency of a microwave oven is far below the resonant frequency of water vapor... and liquid water doesn't have a resonant frequency. Also, the radio energy in a microwave oven can heat many other substances besides H2O. Water isn't special. For example, drops of grease on a plastic microwave dish will be heated far hotter than 100C, and this causes the mysterious scarring which frequently occurs on plastic utensils. Any molecule which is "polar" and has positive and negative ends will be rotated back and forth to align with the changing e-field of the radio waves in the oven. The vibrating electric field of the radio waves vibrates the oil and water molecules and any other polar molecules within the food. Jostling molecules equals heat! Microwave ovens have difficulty melting ice, presumably because the water molecules are bound together and cannot be easily rotated by the e-fields.
If liquid water had a narrow resonant frequency, and if the oven was tuned to this frequency, then the water would be far more opaque to the wave energy. The water in the food's thin surface would absorb all the energy, and only the outside surface of foods would be heated. The thin outer surface of meat would become a blast of steam, and the inside would remain ice cold. [Perhaps the oven would act like a normal electric oven, charring the outside but only heating the inside very slowly.] But because water does not resonate with the microwave frequency, the waves can travel an inch or so into the meat before being absorbed. Microwave ovens heat a thick layer of meat, not a thin layer.
Another note: single H2O molecules have a sharp resonant frequency, but liquid water does not. In order to have a distinct resonance, a water molecule must be alone in space, not bound to billions of identical neigbors. The bonding to neighboring water molecules spoils the sharp resonance and greatly widens the frequency band. Liquid water has a huge, wide absorption band, not a single resonant frequency. In other words, water absorbs all short radio waves. Typical microwave ovens don't even use the best frequency. They should be up around 10GHz frequency rather than the usual 2GHz, but that would make the microwave tube more expensive.

In anycase its not happening unless a REAALLY cool truck's doors fly open right in front of my house on its way to NASA..

I'm just not playing with waveguide for sustained operation..

masonjar · Post by **masonjar** » Sun May 06, 2007 11:06 am

Household microwave ovens are tuned to the resonant frequency of the water molecule. i.e.- the wavelength of one cycle will be on the order of the diameter of a water molecule. This causes the waves to be 'trapped' inside of a molecule and bounce around which raised the electrons of the molecule to a higher energy state. Higher electron energy state = higher temperature.

Both of your statements are astronomically incorrect. The wavelength of a 2.4GHz microwave is 12.5 cm. Water molecules are quite a bit smaller than that.

It is impossible for a liquid to have resonance - or a solid on a molecular level for that matter. Think of a pendulum. If you lightly push it at its resonant frequency then those little pushes accumulate and it starts oscillating with a large amplitude. If you got another pendulum just like it and connected them with a spring, then it would no longer oscillate with that same rate of little pushes. You would find that there is a slightly faster rate - and also a slightly slower rate that will still cause it to oscillate though. If you connect a third pendulum with another spring, then there will be six frequencies that will excite the system - but the amplitudes of the excitations will be lower than it was when there was just one pendulum. If you keep adding more springs and pendulums, then eventually there will be no resonant peaks, and the system will never oscillate - just jostle around and settle down after each push. Water is like this if you replace the pendulums with water molecules and replace the springs with electric fields.

Water will be heated by applying a HUGE range of frequencies of electromagnetic energy. It's a polar molecule, so it is forced to align with any electric field that it sees - just like the magnet in a compass aligns itself with the earth's magnetic field. If you were to get a second magnet and hold it near the compass, it would align to that field instead. If you were to quickly move your magnet back and forth near the compass then it will move back and forth corresponding to your movements. Since all electromagnetic waves have electric fields that switch polarities, all polar molecules will be forced to align with the changing fields just like the compass did for the magnetic fields. So each water molecule is forced to rotate 180 degrees in one direction, then back to the other - over and over again. You can use very low radio frequencies to move water, and it will heat the water, but it will be very slow since the molecules flip directions much less often. The higher the frequency of the electromagnetic wave, the more often the molecules will rotate and the more electromagnetic energy can be transferred into kinetic rotational energy. If you turn the frequency up very high, then the water molecule doesn't have time to rotate the full 180 degrees before the polarity changes and it becomes less effective for energy transfer unless you also increase the intensity of the electromagnetic wave to force it to rotate all the way. In the end, you have frequencies that are too low to be effective and frequencies that are too high to be efficient, and there is a 'sweet spot' of optimal frequencies. In this sense, it is similar to resonance - but resonance is the wrong word to use for it.

You're also confusing temperature with electron states. They are two separate things but somewhat interconnected. Temperature is kinetic energy - it is the effect of moving mass. Electrons are so tiny and non-massive, they have essentially no effect on the temperature of the atom when they move to a higher state - however, the momentum of the photon does transfer to the atom, causing it to move. That electron kicked into a higher state will then have to emit a photon of exactly the same frequency as the one it absorbed - but in a random direction, which will cause a random motion of the atom. When the nucleus of an atom moves, it has gained kinetic energy and when the nucleus stays in approximately the same region, but gets knocked around back and forth by other atoms, we call this form of kinetic energy 'heat' and we can measure its temperature. An atom can be close to absolute zero and still have excited electrons. Electrons only become excited when they are hit by a photon that happens to be the exact corresponding energy that is the difference between the two electron energy states. This is why atoms only emit and absorb specific lines in the electromagnetic spectrum when viewed through a prism or diffraction grating. Heat (temperature) can transfer from one atom to another by emitting and absorbing photons, and this is called thermal radiation. Heat also can transfer through conduction, which is an atom being physically bumped by another atom, and also by convection, which is when an atom physically moves a long distance as being part of a moving fluid. To illustrate my point about the difference between electron states and temperature, I'll mention that you can actually cool atoms to extremely low temperatures by applying precisely tuned electromagnetic waves. The waves applied are slightly below the frequency required to bump up an electron state such that they only transfer their momentum to atoms moving TOWARD the wave source. The doppler effect raises the apparent frequency seen by the atom and the photon will be absorbed, raising the electron energy state, but reducing the temperature since the momentum transfer from the photon to the atom only acts on atoms moving TOWARD the source, and this gives a net cooling effect. This is called 'laser cooling' and allows us to cool atoms down to 1/10,000 of a degree above absolute zero. But at this temperature the electrons in these atoms are still jumping back and forth between energy states.

Sorry for the lecture, it just hurts when I hear people teaching science wrong and I'm compelled to set the record straight.

MikeyT · Post by **MikeyT** » Sun May 06, 2007 2:23 pm

Well, both of you are totally correct. Seems I have been laboring under a mis-conception on how microwaves work for a long time.

If I would have done a Google search first, I wouldn't have made an ass out of myself.

My apologies!

triggernum5 · Post by **triggernum5** » Sun May 06, 2007 2:52 pm

Atleast you didn't accuse me of trying to drink microwaves to gain super-human abilities..

Some of the EM boards I read have some pretty hilarious activists against such things..

possum · Post by **possum** » Sun May 06, 2007 4:53 pm

So, is ethanol suffucienty polar to be heated with, microwaves...that is without a large portion of h2o in the mix ?

triggernum5 · Post by **triggernum5** » Sun May 06, 2007 5:32 pm

Ethanol has both polar and non-polar characteristics, microwaves would heat it.. The conduction of energy from the heated water is all thats needed though.. Kinda like how a plate gets hot because of the food on it..
I came across this in an abstract:
The microwave absorption of certain water soluble polymers (polyethylene glycol, polyvinyl pyrrolidone, proteins, and DNA) in solution is composed of three parts: absorption in the free water, absorption in the substance, and absorption in the hydration layer. Ethanol, sucrose, glycerol, and sodium acetate, which form weak hydrogen bonds or have an ionic nature in aqueous solutions, also have microwave absorption signatures similar to polymers that form hydration layers. The frequency-dependent absorption of the free water and of the hydration layer water is described by a simple Debye relaxation model. The absorption per unit sample volume attributable to the hydration layer is solute concentration dependent, and a simple model is used to describe the dependence. The hydration-layer relaxation time was found to vary from substance to substance and with solute concentration. The relaxation time was also found to be independent of solute length.

Possum, your signature line could easily be the end result of this project, should it end up hapening..

Ricky · Post by **Ricky** » Tue May 22, 2007 3:21 pm

yall are getting way over my head but i use to work on some equipment that had 10000volt twt's that supplied the power. the frequency was 5.56ghz. and the sheilds we used were cork lined. otherwise the eyeballs AND gonads caught hell. i heard that during veitnam guys would stradle these things for about 10sec to kill the squigglies. nothing i know,just something i heard. ecm shop was a long time ago.

MurbinMash · Post by **MurbinMash** » Mon Sep 02, 2024 5:14 pm

So did anyone finish this project? I've been seeing a guy on YouTube that is making fuel out of plastic using several microwave parts and has got a $100,00.00 grant to take it to the next step. I think that if OP is still sitting on these parts and has the will those videos answere almost all of the questions for a plastic still. It's really pretty cool how he has done exactly what you guys are talking about but to turn plastic into petrol. Seems like the only problem he has ran into is that his benzene count is a few percent to high, but you guys wouldn't have that problem with ethanol.
Here's the link to it.

Here's another guy doing the same thing

He has his process in shorts on Ig and youtube is where I first saw him. I'd love to hear about this thing coming to life!

Home Distiller

Microwave Still?

Microwave Still?

microwave

Re: microwave

Re: Microwave Still?