Rossi Lugano/early demo's revisited. (technical)

Just a comparison. I have been wondering where the hockey stick really comes into play.

Edit: Fixed the W/cm² from the older diagram.

(The area of the Lugano reactor Main Tube (excluding Caps) is about 125.7 cm², assuming an un-ribbed tube).

Thanks, LDM.

I am hoping that it may be possible to estimate the input power to temperature curve for my next device. Since I have no other data, I am using the total emissivity of alumina for the Durapot.

(The alumina data you supplied above is for my knowledge base, as I believe it to be at least as good, if not better, than anything else compiled).

In theory, if the radiant and convective power of a regular cylinder at a particular temperature can be estimated by standard calculations, then the reverse should be true; that is, that the combined radiant and convective power should be equal to the input power at steady state and therefore the temperature at a given input power should be calculable for any particular cylinder dimensions and material. I have compiled a theoretical temperature vs input curve for my upcoming cylinder heater. Once completed, I will compare the theoretical curve to the experimental curve.

If I purchase the Aremco Pyro Paint (seems to be $100 US per pint, plus shipping), I may coat the Durapot devices and compare the emissivity changes. I am heading into the wilderness again soon, so I am not sure how much I will get done on the device testing before then.

I hope to cast the coil I wound recently into Durapot today. It will be complicated due to being an unsupported coil (not wound around anything) in a fairly tight space. There are plenty of ways to mess up the coil alignment and wrap spacing while pouring in the wet Durapot. I may also have to rob thermocouples from other experiments, since I think I have run out of new thermocouple wire. Two thermocouples will be cast in: one on the outer skin and one inside at the center.

Thermocouples found. Wires prepared for casting.

Hoping for the best when the Durapot gets poured in...

...And the Durapot seems to have gone in without a hitch. Find out in a couple days if any wires touch that aren't supposed to.

I added an extra 1 mm on the top, so the bubbles and little bits that floated to the top when vibrated can be cleaned off once it sets (before heat curing).

The outer thermocouple is bent up a bunch on purpose, to help it stay stuck in so close to the surface. Only 4.5 mm clearance between coils and the outside, so no room to get too fancy.

In the meantime, which thermocouple quick connects to scavenge from which device...?

LDM , what IR bandwidth is your alumina data referring to? 7.5 to 13 micron (Optris range)? 8-14 micron?

Notice below that the Durapot 8-14 micron emissivity drops with temperature, while the in-band alumina emissivity increases with temperature.

I wonder what the Durapot broadband IR pattern is doing differently? The material is thermally conductive (for a ceramic, anyways).

And... it's alive!

At least until I power it up anyways.

Still needs to sit overnight before warming it up in the oven for the dry-out.
The dark, elongated spot in the center is the outer thermocouple tip, so that turned out perfectly.

Quote from Alan Smith

Best to let that heat-soak at 60-70C for another day if you have time, then bake if you need to.

Per instructions, will air dry 16 to 24 hours, dry at 225 F (107 C) for two hours , then bake at 600 to 900 F (316 to 482 C) for full strength and water resistance.

After it cools, I can attach thermocouple protection sheaths and mini connectors, and the electrical quick connects, and think about firing it up. This should be a fairly low voltage coil, so I may want to fiddle with the power supply, maybe put a rectifier in line. Depends on how sensitive it is to the dial. In theory it should get to about 860 C external at around 65 V.

THHuxleynew ,

It is tricky to get a simple demo of the Lugano effect. It is fairly easy to test the IR spectral vs total emissivity, but a clean COP example is a bit harder. I earlier hoped that a square would be easy to deal with, but it turned out to have a complex temperature distribution no matter how much I tried to even it out. A smooth cylinder is indeed better. Although there will be some inaccuracies due to not being 100 % pure alumina (likely the total emissivity is a bit higher for Durapot, which means it will radiate a bit more than calculated [conservative]), this device should be able to produce a 'COP' of about 4.5 to nearly 5.0 (using the Lugano Protocol) without burning out. Even better, this version has fairly weak convection compared to radiant power, so a 'COP' of 3 should be possible even when ignoring convection.

I suspect that the differences between the Durapot surface and the alumina surface are overall fairly minor. On the other hand, alumina paint will bring the radiant characteritics into the arena of well-studied, rather than the somewhat unknown range of the Durapot 810 material. For this reason, perhaps the Professors can be forgiven if the pure alumina paint was used. If they used zirconia paint instead... then there is no acceptable excuse.

Below is my estimate for the cylinder performance. It will be interesting to see how close this estimate is to the real thing (assuming the coil didn't do anything strange under the Durapot, etc.). The coil is a little shorter than it was laying down, but maybe gravity squished it (evenly I hope).

The 'COP' will be higher than Lugano because this cylinder doesn't have additional cooler caps and rods bringing down the overall temperature of the entire device, and the input wire is low resistance continuing right into the cylinder instead of glowing wires extending out into the rods like the Lugano device.

Quote from Alan Smith

You heater wire (I am sure you are aware) will fail rapidly if you take the temperature up past 1350C. My advice is to take plenty of measurements while it lasts. Good luck!

Thanks. That's why there are two thermocouples embedded in this test unit, once on the surface and one in the core.

The Slab 1 test failed at 1345 C internal temperature (875 C external).

Slab 2 has made several excursions to ~1150 C internal (990-1000 C external), using the same wire as this cylinder. The thermocouple was placed between two coils, 2.5 mm from each, for better wire temperature management in that version.

The main thing is that the wires get a lot hotter than the outside, and to keep them in a safe range.

Hopefully, since the wires in the cylinder are in their entirety closer to the outside surface than previous versions, they can be kept to a reasonable temperature. The Slab units had the coils fairly close to the outside, but only only the outside facing parts of the coils. The cylinder has a constant coil distance to the outside everywhere on the device (about 4 mm).

To get a 'COP' of 5 will probably require me to push the capability of the coils to the edge. It really depends on how the coil reacts in real life compared to my estimates, and how finicky the voltage adjustments get at higher temperatures. There might not be much of an adjustment between 800 C and 900 C.

It will also be interesting to see how much hotter the core gets compared to the outside. We discussed that for pages and pages once regarding Lugano.

Another interesting thing to see will be how the core temperature overtakes the surface temperature. This will be grossly comparable to the Zhang Hang (Jiang replication) test and some other test where the core temp overcomes the external T (Stepanov?) as a "proof" of LENR.

Quote from Alan Smith

I must confess I don't remember that discussion...

Almost best forgotten anyways... The gist of it was for and against "the Kanthal wires should have melted if either the internal reaction or just the wires were heating the outside to 1410 C for 20 days".

Quote from LDM

....

Then you will able to calculate back, after subtracting from the coil power the calculated convective power, the broad band emissivities for Durapot.

Using the established surface temperatures for the Durapot, you then also can adjust the in band emissivities of your pyrometer to match the established surface temperatures.

This will give you the in band emissivities to be used with your pyrometer when measuring the surface temperatures of Durapot.

That would answer some of the questions about the characteristics of Durapot.

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I was thinking more about what the spectral emissivity profile shape looks like.

Since the Durapot is designed to be a thermal conductor, then the only place to conduct heat to is the surface in these heater experiments. Then, if Durapot is a poor broad band emitter, all that improved conduction is for naught.

There is no indication from Cotronics (the manufacturer) that the radiant power characteristics of Durapot are considered. I suspect that they suspect that the Durapot will pot some electronic thing, and if need be, a proper heat sink will be attached.

Improved heat conduction could be accomplished with just smaller particles and lesser inclination to make voids compared to some other ceramic materials. In this case the broad band spectral emissivity might only be slightly changed from typical alumina.

If the additives are used to change heat conduction by some effect other than (or in addition to) modifying the porosity/density of the material, then the broad band spectral emissivity might be quite different than alumina.

Device wired up.

I am going to add a bridge rectifier, since the voltage steps will otherwise be very close together on my SSVR rig.

The rectifier to be used, shown below, is for a 94 A Chevy alternator, and is plenty strong for this job.

(The red leads are for voltmeter connections)