If Robert’s points were not devastating enough, there is more. >From Ahern: “The calibrations stopped at 500C for a foolish if not deceptive reason… blackbody radiation was absorbed by the alumina to a greater extent at lower temperatures. If the power was increased to achieve temperatures of 1200 - 1400C they would have observed the same excess energy [in the dummy as in the active reactor]!
Note: “The dummy reactor was switched on at 12:20 PM of 24 February 2014 by
Andrea Rossi who gradually brought it to the power level requested by us.
Rossi later intervened to switch off the dummy, and in the following
subsequent operations on the E-Cat.” (from page 6 of the original, before
being edited out)
Hmmm… Rossi Intervened in the calibration way back at the start of the
testing ? So he was directing everything both at the start, during
calibration and at the end, during isotope removal - it would seem… so much
for an independent report. As Aretha sez: who’s zoomin’ who?
From: Robert Lynn
-Max average Ecat temp recorded in test 1412°C, 2.8kW heat
output.
- 20mm diameter, 200mm long, thermal conductivity of alumina
6W/m/K at 1400°C means for 1mm wall thickness would have 40°C through-wall
temp differential, for 2mm would be 80°C.
-So assuming 1mm wall thickness (probably conservative) the
internal reactor temp is at least 1450°C
Through wall temperature differentials like that induce
large stresses as external surface is subject to tensile stress and inner
wall subject to compressive stress.
http://www.ceramics.nist.gov/srd/summary/scdaos.htm
Alumina at 1400°C has thermal expansion of 8.5e-6/K, tensile
strength of 22MPa, 343GPa elastic modulus so 40K temp difference means 33MPa
compressive stress at inner surface and 33MPa tensile at outer surface. It
would crack and break letting oxygen in, particularly if made thicker walls.
The external surface crenellations would create stress concentrators that
would only make this worse.
Resistive heating wires inside the alumina tube must
necessarily be a lot hotter than 1450°C in order to push 900W heat into
reactor. But there are no non-refractory heating wires that can survive
such high temperatures. Refractorys can't handle oxygen exposure, and in
some cases are no good with lithium or hydrogen. The wires have to be
joined to non=refractory wires before they contact air and yet at those
joints must not melt the non-refractory wire either. I am also not aware of
electrical feed-throughs that can handle such high temperatures.
1455°C Ni melting point, but nano particles of metal have
depressed melting points.
http://en.wikipedia.org/wiki/Melting-point_depression
The fuel/reaction particles as the source of all the heat
would need to be at a temperature far above the internal reactor surface
temp of 1450°C, probably at least 50-100°C higher, in order to
radiate/convect the heat away to the walls.
So at 1450°C we can expect that the Ni fuel particles are
much hotter, and liquid, making for rapid mixing. Forget special
crystalline structures created by secret processes. LENR in a liquid matrix
seems to run counter to a lot of theories.
Lithium vapour pressure at 1450°C is around 5-10 bar, with
approximately .01g of lithium in reactor and perhaps 20-30mL volume that
means nearly all lithium is in vapour state or as Li liquid condensate on
relatively cooler reactor walls. This reactor is mostly nickel droplets in
lithium gas (the hydrogen will all diffuse away through porous sintered
alumina rapidly at such high temperatures, but perhaps is useful to create
reducing conditions initially).
This internal lithium vapour pressure would also add to the
physical stress on the alumina - probably 5-10MPa, which would likely cause
a failure given any other stresses (such as aforementioned heat flux induced
differential expansion stresses).
Nickel vapour pressure is around 1Pa at 1500°C, so in a
month long test we can expect that along with liquid state of Ni fuel
droplets' continual evaporation and condensation, dissolving in lithium
condensate of Ni within the reactor vessel will lead to steady mixing
between the droplets.
Li + Ni vapour will condense into a thin layer on the cool
walls of the reactor - basically acting as a lithium heat pipe and create
very consistent all-over temperatures. Perhaps with small drops of lithium
condensing and rolling down sides with some dissolved Ni, or otherwise
simply leaving a thin coating of Ni and Li on walls.
Alumina is strongly attacked by liquid lithium reacting with
it to form new compounds - I would expect it to be quickly consuming the
available lithium in the slightly porous alumina.
And we do see that Nickel "ash" has very little Lithium
(.03%, down from 1.17%)
Basically all fuel should end up very homogenous.
Liquid Nickel dissolves alumina and oxygen to a small
degree- about 1.8% and 1.6 % respectively, but only 0-.05% aluminium in
analysed ash - that probably indicates something in error
http://docs.sadrnezhaad.com/papers/176%20(Interaction%20Crucible%20NiTi).pdf
If there is a secondary smaller sealed reactor vessel within
the alumina tube then if must be even hotter.
So so questions that need to be answered:
1/ Why isn't there more aluminium in ash given claimed
temperatures?
2/ How does theory deal with liquid Ni as the LENR matrix?
3/ How do heater wires survive these temps without melting -
it is well beyond temps that non-refractory metals can withstand,
particularly given that they must be a lot hotter than the reactor itself,
and refractory metal wires would fail at external joints. Not to mention
non-leaking feed-throughs of heater wires into reactor while maintaining
seal integrity is probably not possible at such high temps due to
differential thermal expansion of metal vs ceramic and limited strength of
materials.
4/ If within the reactor itself how do heater wires survive
exposure to 1450°C lithium without dissolving/disintegrating.
5/ Given claimed heat flux and internal pressure why didn't
alumina tube fail?
PS: can anyone calculate hydrogen diffusion rates through
the alumina tube?
http://onlinelibrary.wiley.com/doi/10.1111/j.1151-2916.1979.tb19114.x/abstra
ct
quoted eqn+units in this abstract aren't clear to me.
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