Yes internal thermocouple would be in trouble and Inconel wires marginal. To be clear I mean thermocouples externally attached to the dogbone body.
To discus the 'science' behind the dispute between Rossi and Industrial Heat
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I was just thinking that crap steel those shelving brackets holding up the reactor is made of probably has a lower melting point than the thermocouple. A little dab of insulation between the reactor and the metal won't help much. If Galvanized, then sure must stink like danger.
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....was just thinking that crap steel those shelving brackets holding up the reactor is made of probably has a lower melting point than the thermocouple. A little dab of insulation between the reactor and the metal won't help much. If Galvanized, then sure must stink like danger
Very unlikely to be a problem. A point contact with a relatively large surface-area steel strip in cool air would have to be at welding torch temperature to have much effect. And that stuff is not normally galvanised but powder-coated - which is itself a 'hot' process. Very few volatiles involved.
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Since we are now in the "speculation" area:
WARNING - this is speculativeIH will of course know whether the heating element is SiC with weird NTC resistance, since they made the reactor. If it is not SiC we really only have setup change from Wye (dummy) to Delta (active) to explain the figures in the report - unless they made a mistake and just got them wrong! If there is this change I'd reckon it quite likely that it goes with clamp saturation - possible depending on clamp type and exact current waveform in active test.
Reversed clamp etc would of course give X3 input power but there is no way this can be compatible with the data, since however you slice it the thermography error must lead to a significantly lower reactor temperature than that measured. Emissivity is variable with exact material, and so the derating could be less than the "best guess" calculations indicate if band emissivity values are different, but it is still considerable. Extra evidence for lower temp (a bit flakey since photo color is vague) is the reactor body color when hot, and the fact that 1500C internal would probably melt stuff. But none of this is certain, whereas the thermography error is certain.
So: clamp saturation + Thermography - yes. Thermography alone - yes.Reversed clamp or other X3 power input error is only possible if you can find some large COP reduction from another error - no way the thermography issue could give less than COP increase of X2 even with unknowns, and the reactor cannot be endothermic.
Incidentally - one of the additional things that can ONLY be explained by the Thermography error is the COP acceleration. This is exactly matched by thermography error, and no other mechanism would give this large difference. (Clamp saturation has the right behaviour but would be softer).
Finally - since we are being highly speculative. I suspect that clamp reversal or 1 phase power measurement might have been a miscalculation here that was detected by the testers and corrected. It is just not sensible to make these reactors 3 phase - so much more complexity for no reason. But the extra complexity adds electrical mis-measurement possibilities. Anyway - this will never be known. Remember Rossi was used to having a setup with an autonmatic X2.5 COP from using average meter measurement of a 1 phase controlled triode output. PCE-830s stopped that. The X3 COP from a reversed clamp would have got him back to comfortable levels of output power...
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Thomas said..1500C internal would probably melt stuff. But none of this is certain.
Not certain indeed. 1500C is tolerable for a pure Alumina dogbone reactor of the kind that was used, generally they will hold up (in the absence of internal pressure) to 1600C+. Been there, done that.
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Not certain indeed. 1500C is tolerable for a pure Alumina dogbone reactor of the kind that was used, generally they will hold up (in the absence of internal pressure) to 1600C+. Been there, done that.
The issue is the heater, not the reactor - and since we don't know what it was, we cannot say whether it would melt at 1500C. Hence "uncertain".
Tom
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Typical R/T curve of Kanthal SiC. Maybe this helps to eliminate the SiC theory.
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Exactly, just like alumina. And "black" means emissivity=1. So you were agreeing all the time: all's well that ends well.
YOU have not understood nothing and maybe that you are NOT able to see the photographs ! Are you blind ?
The "black" Alumina is emitting a lot more then the alumina pipes meaning that the alumina pipes have LOW emissivity.And.... O Dear ! You look like a little baby ! One day away (working) and you already start saying again your LIES !
What are you chatting about the a 3kW input (we already discussed your presumptuous analysis and discarded it !) and discarded TC measurement ?!! Have you EVER tried to make a good thermal contact on Alumina ? IF you don't know Alumina is a very good thermal insulator and making a good thermal contact on an external part of a pipe is extremely critical. LOOK AT MFMP.... -
YOU have not understood nothing and maybe that you are NOT able to see the photographs !
Triple negations in one sentence! Must be a record! -
I don't volunteer that lightly
Oh I see so YOU are not a Scientist doing all that for the sake of true ! You are explicitly connected to IH or at least in a state of psychological subjection. So THAT why you are here.I see that any time somebody give you an answer you mess up things in order to select what is good for you (and IH) and hide what is in contrast with what you write.
We all know the T^4 law even IR thermometers manufactures know that law and invert it to convert the energy measured by the bolometers in to temperature. When one wants to calculate the energy again the two emissivity factors in the formulas cancel ! -
Triple negations in one sentence! Must be a record!
I was meaning that Mr. AndreaS. has not understood the topic he was writing about, because, probably he was not able to see the photographs.... -
Extra evidence for lower temp (a bit flakey since photo color is vague)
A further issue with trying to derive anything from the apparent color temperature in those photographs without a display reading: there are no statements linking the photographs to a particular point in time in the test. They could just as well be from the beginning, when the device was still heating up, as from the time of peak output. What the photos tell us is that the reactor got hot enough to glow at some point, which is not a very useful detail. -
Quote from Thomas Clark
I don't take (volunteering to be consultant for IH) lightly
Quote from randombitioOh I see so YOU are not a Scientist doing all that for the sake of true ! You are explicitly connected to IH or at least in a state of psychological subjection.
I have no explicit connection to IH. And I can't see why I would be in a state of psychological subjection? I'm certainly not behaving like that when I argue with Dewey here about his bullying and reprehensible behaviour re Frankwtu. In fact I think I'm just not the psychological subjection type - can't say I've ever been in that state.QuoteSo THAT why you are here.I see that any time somebody give you an answer you mess up things in order to select what is good for you (and IH) and hide what is in contrast with what you write.We all know the T^4 law even IR thermometers manufactures know that law and invert it to convert the energy measured by the bolometers in to temperature.
Well over T^4 we both agree - completely - so i can't see any messing things upIQuoteWhen one wants to calculate the energy again the two emissivity factors in the formulas cancel !
If you agree there are now two emissivity factors, not one, we have made progress. If you look at the various references - or eyeball the alumina emissivity spectrum yourself - you will see these two factors are assuredly not the same - so they can't cancel.But - and this is a bit more complex - even if they were the same they would not cancel. The total emissivity scales the output power linearly (obviously). The band emissivity scales the temperature by (roughly - it varies with temperature) - e^-0.5. The output power than varies again as T^4. So the effect of band emissivity on output power is thus roughly e^-2. You see the difference? Square law (roughly) vs linear.
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If you agree there are now two emissivity factors, not one, we have made progress.
No Mr.Clarke NO. The Only progress I see is that you are playing with words and phrases.
When I wrote the two "emissivity factors" I was obviously meaning the in the direct ( E-> T ) end inverse ( T->E) formulas that are of course the same and so CANCEL. -
@randombit0
I think we have now almost reached the end of useful communication. Let me summarise the differences:(1) You think band and total emissivity (defined as I do above) are the same. I and many others think they are in principle different, and specifically different in the case of alumina at high temperatures.
(2) You think that the two places in which emissivity are used are inverse, so that if the emissivity were the same, then they would cancel. This is not true, and perhaps I need to explain what you have done wrong. In the process i will give you the correct relationships (though the E->T one is approximate - there is no precise analytical solution and the exact power varies with temperature).
(E->T) this is how the band emissivity affects the Optris temperature indication. You can check using the Optris instrument, or work out, that here T ~ Eband^-0.5. Anyone with access to the internet can use a black body band radiance calculator to work this out, setting band 7-13um. You will see roughly the power law dependence I indicate.
(T->E) this is untrue. What you mean is:
(E -> P) and
(T->P)
In this case the total emissivity determines the radiated power as P ~ Etot*T^4. This is the definition of total emissivity. And I think we agree here.So if we have Eband = Etot you can see from these two equations that the two things do not cancel - nothing like.
To be fair, I vaguely thought that they should cancel before I started working out the real numbers. That was a long time ago! And I had the humility at that time not to trust "vaguely thought" till I did the precise calculations.
So, for these two points of difference, I can prove what I say is correct, if you have the patience, using web resources like black body radiance calculators.
Best wishes, Tom
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MFMP ε test.
Skip to about 54:40 and run to at least 58:00 to see the best part.External Content youtu.beContent embedded from external sources will not be displayed without your consent.Through the activation of external content, you agree that personal data may be transferred to third party platforms. We have provided more information on this in our privacy policy. -
@Alan Smith
What did you use to heat the alumina to 1600°C? -
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What did you use to heat the alumina to 1600°C?
Big propane torch. But if you aren't too worried about wire life you can just about manage this with Ni-chrome wire protected with Kiln cement.
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MFMP ε test.
Skip to about 54:40 and run to at least 58:00 to see the best part.Thanks Paradigmnoia: This Video shows that the room for (optris readings) interpretations is large, and if somebody does not know how to handle the optris, then he will be way off.
But we don't what happened in Lugano. We know neither what type of Alumina was used nor what optris settings were used a what time of the game.
From this viedo we can only conclude that the low guess of Thomas is way off and very probably also the high readings of the experiment masters.
But keep in mind: Rossis fuel only melts above 1500C and they have identified molten pieces. But this can also easily happen in a local short burst of a runaway reaction.The other interesting point of the video is that 450 Watts for the test seem to be inline with what we read in the Lugano summary.
But 900 Watts give more than 900 C because, may be, alumina is not able to radiate the heat efficiently.This opens a new path for speculations...
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@Wyttenbach
We actually know a lot about the Lugano materials, thanks to a patent application and the Lugano report.
The ribbed cement and caps are surfaced with Durapot 810 alumina base thermal conductive cement, and the rods are commercial tight grain 99.9% alumina.
Surface roughness, porosity, and ribs all increase the emissivity to some degree.I agree there is a fair bit of wiggle room.
For example, in theory, a high percentage (maybe even 100's of watts) of coherent short wave IR caused by a reaction could exit the alumina almost unimpeded in some wavelengths, depending on optical thickness, and not heat the alumina or appear in the IR spectral view band.
The wires would capture some of this, due to a broadband ε of 0.7 for Kanthal to an ε of up to 0.88 of Nichrome, and heat up anyways. This could reduce current input...
But that is of course both speculative and very complicated to model.
