FP's experiments discussion

Horst: Regarding vold fraction and its implications,

Fleischmann was very well avare of the issue as referred in the previous post, ref

FP's experiments discussion

Quote from Robert Horst

Much of the same material is covered in the Lumanauw MS Thesis which you can freely access. This reference also covers the details of bubble formation and combination and talks about gas holdup that causes layers of “froth.” (See p. 92)

D. Lumanauw, Hydrogen bubble characterization in alkaline water electrolysis, 2000

https://tspace.library.utoront…/1807/14070/1/MQ54129.pdf

Thanks a lot, Robert. Suggesting this thesis, you provided the second fundamental contribution to this discussion, in addition to the link to the "IMRA time lapse" video.

Figure 4.14, showing the froth structure model, is very enlightening and should definitively close the long controversy about the build-up of foam inside the F&P cells.

Your considerations are interesting too, but let me add a couple of observations.

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In the 1992 paper, the long steady increase in voltage at constant current is due to increasing bubble volume. By using a constant current source, bubbles increase resistance which increases voltage which in turn creates more bubbles in a positive feedback loop until eventual thermal runaway.

The positive feedback mechanism you have described applies for sure in the last part of the experimental evolution of each cell, after the start of boiling on the hottest spots of the electrode surfaces, when water temperature is about 70°C. I doubt it could have affected the previous period of slow increase, because before the water starts to boil, the amount of bubbles produced is strictly related to the current, which is constant. The slow voltage increase in this period is probably due to the dilution of the electrolyte caused by the daily filling up of pure heavy water, to compensate for the loss due to electrolysis. As noted by Wilson, part of this loss can be attributed to the liquid entrained in the gas stream at the exit.

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The Fleischmann graph in Fig. 8C shows the lowest power as .862 W at 200 ma which would make V0 = 4.31 V.

There is probably a typo. It should be .882 W in Figure 6C.

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The enthalpy calculation starts when the cell is supposed to be half empty. During the last 10 minutes, the average power is 37.5W at .5A which makes the average voltage 75V. We can assume conservatively that the voltage ramps linearly during that time from 50V to the final value of 100V.

I would suggest to avoid guessing the trend of cell voltage on the basis of the info contained on page 16 of the F&P paper (1). Unless you know the real trend from the original data logging, it's impossible to know what happened in the last 10 minutes. Moreover, we don't even know the cell to which the data of page 16 refer.

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Using 1.54V for V0, if the start of the last half-cell boil off is 50V, then at that time Vratio = 1.54/50 = .031. Using equation (B1), the void fraction at that time is .95 (only 5% liquid).

This is an interesting approach for a first rough estimation, but we should consider that the Maxwell relationship was derived for a homogeneous distribution of bubbles, which is not the case of the F&P cells, especially during the last minutes of the boil-off. Actually, during this period of time, the videos show a lower thin transparent (i.e. mostly liquid) layer whose thickness progressively reduces to zero. Therefore, the voltage increase may also depend from a strong increase in current density, as shown in Figure 1.3 of the Lumanauw thesis.

(1) http://lenr-canr.org/acrobat/Fleischmancalorimetra.pdf

Quote from oystla

The original issue Ascoli have raised wrt how much water was boiled off in the last 10 minutes is only intersting wrt how much excess heat there really are at elevated temperatures: Very high, medium or low excess ?

Answer: NO excess. ZERO. Even the 10 minutes period has no sense, it's a pure invention.

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Also to note: Fleischmann was very well aware of pitfalls and possible issues, and answered and investigated all criticism they were presented.

Well, looking at this letters to Miles written from England while the experiment we are talking about was underway in France, it seems that he was very active in asking others to answer the criticisms to his work:

So, MF left to himself only the Olympian introduction and conclusions of a collective response to the criticisms raised by only one person.

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But the evidence of excess heat persisted even at their later work, as presented in the Icarus paper [2], They even state in this one “Foam rise in the calorimeter at the boiling temperature has been minimized.”

The major evidence in this paper is that its authors have disavowed the previous MF declarations about the absence of foam in the F&P open cells.

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And the Lonchampt precise replication paper also prove excess heat [3]

It only proves that Lonchampt precisely replicated also the F&P errors.

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So the Hypothesis of Ascoli that F&P where wrong in the 2,5 moles of water the last 10 minutes is I consider weak.

Weak is a unexpected good progress. You are on the right track.

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But I will not discard the possibility that the water level may have been somewhat lover, But even 50% lower water content would still result in significant levels of excess heat, i.e. the F&P hypothesis of increased excess heat at higher temperatures would still hold.

There is a much simpler method to estimate how much water was present at the beginning of the last 10 minutes, assuming that you know which last 10 minutes of which cell you are talking about. Find out how much electric energy was fed in this period, remove the heat lost by radiation, calculate how much water could have evaporated by the remaining heat and you get best possible estimate.

Quote from THHuxleynew

My claim that you refer to is that water that has been "boiled" - transitioned to vapour state - could still leave the cell calorimetric boundary in a condensed (liquid) state.

I recall you said this would be in the form of droplets being pushed up by vapor pressure. I pointed out this is impossible for several reasons, which you ignored, mainly:

The vapor pressure is a tiny fraction higher than 1 atm. It cannot push anything. The cell outlet is far too wide for it to build up any measurable pressure.

It would have to lose so much water the droplets moving up would be readily visible. There would be macroscopic quantities of water moving up.

No liquid water falls out of the top of the cell onto the surroundings. (Yes, they did check for that.)

Most important: The energy balance is zero during calibrations. How could your mechanism only work with Pd-D2O in cells that produced excess heat before and after the boil off event?

To be blunt, your hypothesis is impossible nonsense.

Quote from THHuxleynew

The many F&P reported cal tests never entered boil-off mode. I'm happy to take such calibration evidence if you can find it anywhere in F&P's published output?

The Pd-H blanks did enter boil off mode, and so did Biberian's. Furthermore many of the Pd-D cells did not work. They boiled off without producing excess heat before, during or after the event. I am sure this was reported by P&F, and I am also sure they told me, in person, and described it at conferences. But I cannot find the papers describing it. My search programs do not always work, and I do not have every paper in electronic format. So, you will have to take my word for it.

Do you really, seriously think that two of the most accomplished electrochemists of the 20th century would not calibrate?

Quote from JedRothwell

My search programs do not always work, and I do not have every paper in electronic format.

Some of the papers from F&P and Biberian describe how water is left in the bottom of the cell during calibrations, because it stops boiling the moment the liquid falls below the cathode. I am sure this is in some of the papers but it is not something I can search for with a simple search technique. (Electronic searching has its limits. AI will help in the future.)

Quote from JedRothwell

Some of the papers from F&P and Biberian describe how water is left in the bottom of the cell during calibrations, because it stops boiling the moment the liquid falls below the cathode. I am sure this is in some of the papers but it is not something I can search for with a simple search technique. (Electronic searching has its limits. AI will help in the future.)

AI will tell you that the cells used in the experiments for which water is left on the bottom, because liquid falls below the cathode, are of the model shown in Figure 1 of the 1992 F&P paper, where the cathode is suspended above the Kel-F support, but that the four cells used in the 1992 experiment were different and the electrodes were resting on the support (1).

On request, the AI will also explain why in this last model of cell the liquid cannot fall below the cathode.

(1) FP's experiments discussion

Ascoli, "The major evidence in this paper is that its authors have disavowed the previous MF declarations about the absence of foam in the F&P open cells."

Well, NO, they have always been aware of foam and bubbles , as described by Fleischmann [ 1]

"We once had a batch of D2O that foamed badly. We traced this back to the Girdler-Sulfide process used by AECL (Atomic Energy of Canada Ltd.)."

“

[1] http://lenr-canr.org/acrobat/Fleischmanlettersfroa.pdf

Ascoli: "There is a much simpler method to estimate how much water was present at the beginning of the last 10 minutes......"

Like your method? Take pictures of some old fuzzy videos, interpret light shining on the cells as foam, disregard the differente behaviour of of calibration cells, blank cells vs cells exhibiting excess heat, assume F&P lacked knowledge or disregarded obvious artifacts of droplet carry over, foam,...

Ascoli:"...seems that he was very active in asking others to answer the criticisms to his work":

No, Fleischmann answerred critisism of his own work, and let others answer critisism of their work, like Mckubre answer ciritism of Mckubre's work.

FP's experiments discussion

Quote from Robert Horst

As the void fraction increases, the conductance from anode to cathode decreases (in other words, the resistance increases). The 1992 paper omits the void fraction in the enthalpy calculation which is a serious error as shown below. This term of art should have been well known to a leading electrochemist like Fleischmann.

In the 1992 paper, the long steady increase in voltage at constant current is due to increasing bubble volume. By using a constant current source, bubbles increase resistance which increases voltage which in turn creates more bubbles in a positive feedback loop until eventual thermal runaway.

.

.

.

e = (1-Vratio)/(1+Vratio/2) (Equation B1)

where e is the void fraction and Vratio = V0/V

.

.

the void fraction at that time is .95 (only 5% liquid).

This means that the enthalpy calculation should have been based on 5% full instead of 50% full and the calculation is off by about a factor of 10.

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Again, Fleischmann where very well avare of the role of vold fraction and ITS implication on the voltage, as referred to in my prevoius posts.

Also, the void fraction you explain above would we in the path of electricity between the anode and the cathode.

The highest void fraction would be in the shortest distance between the anode and cathode, and Gradually reduced void fraction further away to achieve same resistance over the longer path of electricity.

And If the cathode exhibited film Boiling, your analysis would be wrong, but the consequence the same, increased voltage, as stated by Fleischmann at several occations.

The void fraction may therefore be much lower elsewhere in the cell, i.e higher water content in the cell, than your analysis shows, i.e. 50% filled cell at the start of the last 10 minutes is still possible.

FP's experiments discussion

Quote from Ascoli65

There is probably a typo. It should be .882 W in Figure 6C.

I would suggest to avoid guessing the trend of cell voltage on the basis of the info contained on page 16 of the F&P paper (1). Unless you know the real trend from the original data logging, it's impossible to know what happened in the last 10 minutes. Moreover, we don't even know the cell to which the data of page 16 refer.

This is an interesting approach for a first rough estimation, but we should consider that the Maxwell relationship was derived for a homogeneous distribution of bubbles, which is not the case of the F&P cells, especially during the last minutes of the boil-off. Actually, during this period of time, the videos show a lower thin transparent (i.e. mostly liquid) layer whose thickness progressively reduces to zero. Therefore, the voltage increase may also depend from a strong increase in current density, as shown in Figure 1.3 of the Lumanauw thesis.

You are right that the .862 was a typo. Using .882 W, that calculation would change V0 from 4.31 to 4.41.

Also, you are correct that we have no way to know the exact voltage at the beginning of the final 10 minute period. In the graphs of Fig 6, the width of the vertical voltage line represents about 50 minutes according to my measurements - it is certainly more than 10 minutes. However, in all four graphs you can clearly see that it hits 50V before the last jog of the vertical line to the right, meaning that the last 10 minute period must start at 50V or more. Using 50 is still conservative.

I did find a math error though. We cannot use 1.54V for V0 because of the way I assumed the same current for the initial and final conductance. Instead, we need to use the minimum voltage that could drive .5A. In Fig 6C, that is at power 3.355W or 6.71V. Rerunning the numbers, that changes the result to being off by a factor of 2.7 instead of 10. The COP comes to 1.83 and the results are not so clear. There are still several other errors, like using 10 min in the calculation while the text says it took 11 min, the overestimate of enthalpy out due to remaining liquid after boil off, the uncertainty in the voltages, and the distribution of the bubbles. But it still seems pretty clear that the paper calculation of excess energy is way off due to omitting any consideration of void fraction.

As you say, this is still just a rough estimate due to the fact that the bubbles will not be evenly distributed throughout the remaining liquid.

Quote from oystla

Again, Fleischmann where very well avare of the role of vold fraction and ITS implication on the voltage, as referred to in my prevoius posts.

Also, the void fraction you explain above would we in the path of electricity between the anode and the cathode.

The highest void fraction would be in the shortest distance between the anode and cathode, and Gradually reduced void fraction further away to achieve same resistance over the longer path of electricity.

And If the cathode exhibited film Boiling, your analysis would be wrong, but the consequence the same, increased voltage, as stated by Fleischmann at several occations.

The void fraction may therefore be much lower elsewhere in the cell, i.e higher water content in the cell, than your analysis shows, i.e. 50% filled cell at the start of the last 10 minutes is still possible.

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It is true that the calculation assumes that bubbles between anode and cathode have about the same distribution as elsewhere. But the cell construction has the anode surrounding the cathode, and the bubbles need to rise up to fill most of the area above the cathode to exit. It is clearly just an estimate, but seems unlikely to be wrong by factors of 2 or more which would be needed to make the paper's conclusion correct.

Regarding film boiling, I do not see how that could increase the resistance by that much. Do you have a reference?

Also remember that the high voltage and resistance starts a full day before the final 10 minute period. If it started to boil then, the liquid would boil off long before the final 10 minutes.

And if the cell is boiling furiously, the bubbles are displacing liquid and you can no longer use the liquid levels (even if correctly measured in the videos) to determine the liquid volume. The paper completely ignores this factor.

Huxley, "Also remember that the high voltage and resistance starts a full day before the final 10 minute period."

A day before ?

I did a similar analysis as Lonchampt at one point, and found some 15% excess from last fill of cell to cell was dry:

For last refill of cell 1, the cell was at approx. 19 Volts at araound 12:00, and the cell was dry at 22:25...,, ref.

FP's experiments discussion

Horst: "Regarding film boiling, I do not see how that could increase the resistance by that much. Do you have a reference? "

Assuming there is LENR happening in the cathode, it should get very hot, and I believe could create film Boiling, a gaseous layer on the cathode should increase the resistance a fair amount. How much? Depends on the conditions I would think, like gas layer thickness.

Also there is another indication of hot cathodes in live cells:

After the current was turned off the cathodes had high temperatures for hours, while blank cells dropped off immediately.

Regarding possible carry over during Boiling, here is one comment from Fleischmann on that issue:

"Douglas Morrison first of all raises the question whether parts of the cell contents may have been expelled as droplets during the later stages of intense heating. This is readily answered by titrating the residual cell contents: based on our earlier work about 95% of the residual lithium deuteroxide is recovered; some is undoubtedly lost in the reaction of this “aggressive” species with the glass components to form residues which cannot be titrated."

Ref.

http://coldfusioncommunity.net…eischmann-and-pons-reply/

Quote from Ascoli65

Let me provide a contribution to clarify this issue.

The mechanism you are talking about is one of the potential way in which the energy balance of the cell could have been affected by the larger phenomenon of liquid entrainment. But this entrainment is the wrong interpretation of the results of the boil-off experiments.

There are several mechanisms that could cause liquid entrainment. This is a tentative list (I would ask you and others to suggest possible integrations or improvements):

A – microdroplets produced by the electrolytic gas bubbles at the moment of their formation or when they exit the water;

B – droplets, produced as above but by the water vapor, whose dimension depends on the intensity of boiling;

C – foam which build up on the water surface and that, when the level is close to the top, could overflow from the cell;

D – and finally droplets produced by the vaporization/condensation mechanism mentioned in your comment.

In A, B and C mechanisms, droplets and foam contain some salt, so that both the enthalpy balance and the salt inventory are affected. On the contrary, mechanism D produces droplets which does not contain salt, so it affects the energy balance, but not the salt inventory.

As for the period of occurring:

A -- is always present (but becomes negligible with respect to B after its beginning);

B -- begins when water temperature is close to the boiling point and the vapor bubbles formed on the electrodes are allowed to surface without condensing in the water mass;

C -- could occur in some occasions at the beginning of B mechanism if the cell is almost full;

D – condensation of boiled water should happen above the water level after the beginning of B, but at that point the water level is still high (not so much empty space above it) and temperature is close to boiling point, so it seems to me that it is a rare and negligible mechanism.

In any case, summing up all these mechanisms of liquid entrainment, their effect on the energy balance is negligible and cannot explain the alleged excess heat claimed in the F&P paper. With this respect I was wrong when, in September (1), I concluded that the entire excess heat "was easily attributable to the underestimation of the liquid content in the steam".

I was basing my explanation mainly on the deductions of Morrison, who seems to have never doubt the timing proposed by F&P. In fact in his critiques posted on May 1993 (2), he wrote: "there is the assumption that ALL the liquid present in the tube 600 seconds before dryness, was boiled off. That is none of it was carried out as a liquid, from the test tube. Now the video shows that there is highly turbulent motion. And as Kreysa et al. [3] showed, 74 seconds after the palladium becomes dry, temperatures of a few hundred degrees can be reached. Thus it is reasonable to expect that with such a chaotic system, some fraction of the liquid is blown out of the test tube as liquid and therefore should not be counted. The existence of such a fraction is omitted from the simple Fleischmann and Pons calculation. And no attempt to measure this fraction is described."

As shown above, Morrison suggested an explanation based on liquid entrainment without objecting the 600 s period reported in the F&P paper, but this is not the right way to explain the excess heat calculated by F&P. I found my alternative explanation in two steps.

The first step concerned the timing. It happened by chances: trying to synchronize the images of the "1992 Four-cell Boil-Off" video with the events indicated on Fig.8 of the F&P paper, it appeared a first clear discrepancy, as illustrated in the jpeg posted on October 20 (3). My interpretation was still erroneously because it was still based on liquid entrainment, in this case of foam. However the timing was already modified with respect to the F&P assumption.

The second step, arrived a few days after, on October 31, when it resulted from a simple calculation that the electric energy fed to the cell during the boiling period was sufficient for vaporizing all the water, without considering any liquid loss due to entrainment (4).

This explanation, coupled with the "foam issue", provides the most obvious and simple interpretation of the results reported in the F&P paper of the 1992 experiment. It doesn't imply that no entrainment occurred during that experiment, but this entrainment is no more necessary and can be neglected. It could have amounted to a few percent of the water loss. In reality, almost all the water left the cell as dry steam thanks to the electric energy fed into the cell and this interpretation also comply with the exact salt balance claimed by MF.

(1) FP's experiments discussion

(2) https://groups.google.com/foru…on/_fke9KWvOWE/discussion

[email protected]

(3) FP's experiments discussion

(4) FP's experiments discussion

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No-one is saying here that entrainment (of the different types possible) needs to happen. Only that if the apparent heat balance is wrong, entrainment is one possible reason for the discrepancy. LENR is another, as is mismearurement due to wrong chracterisation of water level. Before reaching for LENR all the mundane possibilities such as entrainment need to be considered and ruled out (that means careful sympathetic consideration, rather than blanket dismissal). Thus it is fair to give mundane mechanisms here the same careful and sympathetic attention that people on this site would most likely give to an LENR hypothesis.

More generally, the F&P experiment had very different condition at different times, so all these arguments need to restricted to specific conditions where they can more accurately be estimated, and not generalised over other conditions - as some the the argument above appears to be doing.

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This topic has been flogged to the point of exhaustion, and since contests between the unproven and the improbable seldom bear any edible fruit, suggest that you guys call it a day.

I agree completely. And my earlier point was that if LENR could be reliably and reproducibly demonstrated to produce substantial and significant amounts of excess heat for sufficient time and/or could self run for significant time, none of these arguments would make sense and neither would lack of acceptance of funding by the general scientific community. Vague and arguable results won't cut it after all these years. Same applied to Steorn and same applies to BLP/Mills.

Quote from seven_of_twenty

And my earlier point was that if LENR could be reliably and reproducibly demonstrated to produce substantial and significant amounts of excess heat for sufficient time and/or could self run for significant time,

Define sufficient time and significant time.

We've discussed that many times. What's your thoughts on it? And what would it depend on mainly?