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Josh Campbell

Sat Jan 26 2013, 02:07AM

Registered Member #5258 Joined: Sun Jun 10 2012, 10:15PM
Location: Missouri - USA
Posts: 119

Is the idea here to pinch or bend the plasma current forcing it to flow through the plates? It's no tokamak but sounds interesting.

Ash what are the temperature ratings on your high temp NdFeB magnets? Also what is the remanence on them (Br)? I know most normal NdFeB's are around .8 to 1.4 with a curie around 310C. Just asking because I've never seen NdFeB magnets with a curie higher than about 350C to 400C half of the peak gas temp in your average fire. And most loose much of their magnetic force well before curie.

Edit: Even the high temp rated ones seem low when were talking fire:

Still a cool idea!

Ash Small

Sat Jan 26 2013, 10:42AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

2bytes wrote ...

Is the idea here to pinch or bend the plasma current forcing it to flow through the plates? It's no tokamak but sounds interesting.

That's the general idea.

2bytes wrote ...

Ash what are the temperature ratings on your high temp NdFeB magnets? Also what is the remanence on them (Br)?

They are actually SMCo, my mistake. Curie temp is between 750C and 850C, but usable temp is 350-550C.

Grade 28, for example, at 350C has a Br of 1.1T, if I'm reading the table correctly.

Here's the .pdf of the full catalogue:

]smco_combined_120719.pdf[/file]

radhoo

Sat Jan 26 2013, 01:53PM

Registered Member #1938 Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 699

I also wondered how a simple plates-and-plasma-cell would work, so finally got 5minutes to run a quick test. The results are interesting, and this should be researched further. The setup:

Two iron plates, placed in parallel planes at 0.8mm - 1mm apart, using some insulators. Magnets added on both sides, with opposite poles oriented towards the other. So one plate acts like N pole, while the other is south.

Using a small butane torch, plasma was inserted between the plates. The multimeter shows a potential difference of 30mV DC, but with some flame trajectory adjustments, this went up to 100mV. No further measurements where done. I expect the current to be low, and proportional to the "flame size" or quantity of plasma pushed between the plates.

I would try the following:
- using non-ferrous plates.
- using metal plates with opposite electrochemical character, like in a electrochemical battery. This would help attract the ions
- using a radioactive alpha emitter as a ion source
- using stronger magnets
- changing the distance between plates
- adjusting the setup geometry to capture more (or better) of the flame's plasma.

Marko

Sat Jan 26 2013, 04:26PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Hi guys

From what I know, your idea of "drawing current from plasma directly" is basically an MHD generator. It's easiest to imagine it as a linear homo-polar generator, or a railgun in reverse if you want it put that way. Logically, you need plasma to entr the device at very high speed and be highly ionized and conductive in order to provide useful energy output, neither of which is really met by a typical fire.

You could try the idea with salty water for fun though - it should work both as an MHD generator and a pump!

If you still wanted to get it going with flame, perhaps the best shot would be to try it with a super hot hydrogen/oxygen torch and find a way to accelerate the flame as much as possible - you'd basically be making a mini rocket engine, and then extracting the kinetic energy of the plasma by MHD device.

Marko

Proud Mary

Sat Jan 26 2013, 06:00PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Marko wrote ...

You could try the idea with salty water for fun though - it should work both as an MHD generator and a pump!

Michael Faraday first demonstrated MHD in the River Thames in 1831. He showed that electricity was generated when water flowed between copper disks in the field of a horseshoe magnet.

Reaching

Sun Jan 27 2013, 12:07PM

Registered Member #76 Joined: Thu Feb 09 2006, 10:04AM
Location: Hemer, Germany
Posts: 458

Hi. i found this interesting and tried it out by myself. First of all, i was able to get around 1 volt with two 3mm thick metal plates, one out of copper, one out of aluminium. for isolation i used some glimmer pads i found on my table.
In my first test i used 6 neodymium magnets but i found out that they loose magneticity as they heated up and simply fell down. so in my last test i tried it out without magnets at all.

The highest voltage was around 1.069 Volts with the torch full powered and exaxtly aligned.

the last test was really dissapointing. i tried to measure the current but wasnt able to get some results with my multimeter, so i tried to measure the voltage drop with a shunt 100 ohm resistor.. theres simply no current flow i could measure here.

StormInABottle

Sun Jan 27 2013, 01:46PM

Registered Member #9252 Joined: Fri Jan 04 2013, 06:27AM
Location: Andromeda
Posts: 253

Are you kipkay >.>

Conundrum

Sun Jan 27 2013, 02:42PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059

Very interesting, I would speculate that this works by the flame acting as an electron carrier between dissimilar metals.
Easy to test, use two copper plates or other metal and see if it still works.

Re. current, a more feasible method is to charge up a tantalum capacitor bank having first left it shorted to discharge any remaining voltage so as not to bias the test.
Therefore by knowing the capacitance in Farads the resultant energy transfer in Coulombs can be calculated by measuring the time T it takes to charge up to 1 Volt.

Ash Small

Sun Jan 27 2013, 02:59PM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Conundrum wrote ...

Very interesting, I would speculate that this works by the flame acting as an electron carrier between dissimilar metals.

It doesn't seem to work without the magnetic field. Therefore, it seems it works on magnetic deflection, which is the basic theory initially suggested by Patrick.

Reaching

Sun Jan 27 2013, 04:12PM

Registered Member #76 Joined: Thu Feb 09 2006, 10:04AM
Location: Hemer, Germany
Posts: 458

with similiar metals (copper-copper) and similiar test circuit as shown above i was able to get 0,506volts between the plates.. still no current measurable.

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