I agree the coil is imbedded within the alumina shell Maybe the end caps are heat sinks?
I still think the unit works off induction from the coil On Tue, Oct 14, 2014 at 11:15 AM, Bob Higgins <[email protected]> wrote: > Robert, I think a lot of your observations are spot on. I would like to > continue discussion of the likely construction of the latest IH hotCat. > You are likely correct that the corrosion of liquid and vapor phase lithium > would be terrible for use of a metal reactor vessel. That is probably why > they switched to alumina. > > Alumina is a wonderful ceramic from a thermal, mechanical, and electrical > properties standpoint. Its only drawback is that it has to be fired at a > very high temperature to form it, but Coors has been doing it for decades. > It is high thermal conductivity, very low electrical conductivity (a good > dielectric), and extremely chemically stable. It is mechanically tough, > even in thin wafers (it has been used as a substrate for hybrid electronic > circuits also for decades). > > One thing that strikes me is that heater wires at this temperature have 2 > related constraints: a) they must be sealed away from oxygen, and b) there > must be a good way to remove the heat from the wire to prevent hot spots > from run-away temperature rise. Regarding a) - long before these wires > melt, they will oxidize and burn up in oxygen. Usually this means that the > wires must be sealed inside a ceramic oxide to prevent exposing the hot > metal heater wire to free oxygen. For b), it is necessary to spread the > heat from the wire. This is usually done by bonding the wire to another > ceramic body, usually with a refractory cement. > > Now lets consider the issue of using a refractory cement to bond the > heater wire to the inside of a ceramic tube. You would need to have the > coils pre-formed and slipped inside such a tube and then paint them inside > with the refractory ceramic. This would be very painful. Instead, I > imagine a central alumina tube with the heater wires wrapped on its > outside. This could then be painted with a refractory cement to seal out > the oxygen and help thermally spread the wire's heat over the ceramic tube. > > Normally such refractory cements have an organic binder that dries in air > at room temperature. They also contain both low temperature glass and > ceramic fibers. As the cement is heated, it would first drive off any > organic. Then the glass melts and further binds the joint. Then as > temperature gets hotter the glass wicks into the ceramic fiber and a > glass-ceramic hybrid is formed. The joint can be air tight at basically > all temperatures until the ceramic itself melts. > > Also, because we are talking about 3-phase coils, there will be > cross-overs of the wire that must be brought out to the ends of the > reactor. These will have to be very carefully managed so as not to short. > This is another practical reason why I believe the coils must be created > wound on the outside of an alumina tube; that tube being coaxially internal > to the alumina tube that is visible on the outside. Probably after a first > heating of the coil (either self-heating or having been placed in a curing > furnace), the inner alumina tube with the wrapped coils could be coated > with a similar refractory cement and slipped (glued) inside the outer > tube. Imperfect cement contact between the inner and outer alumina tubes > could cause the appearance of uneven heating on the outside tube. > > Another point has to do with how the heat is conveyed from a LENR > reaction. Since the LENR reaction is likely a nano-scale event, heat must > be conveyed from the reaction in a way that doesn't make the NAE the > hottest spot. Otherwise, none of the reported melt-downs would be possible > - the NAE would evaporate itself before it could create enough heat to melt > the macro apparatus. This implies that the heat is conveyed from the NAE > by photons - not such high energy that they readily escape the reactor, but > high enough that it can penetrate through a mm or so of the surrounding > materials (which could be LENR powder), depositing heat as the photons are > attenuated in penetration. The important take-away is that the NAE cannot > be the hottest spot - it must heat its surroundings more than itself. > Given this, it is possible that the heat from the LENR is being absorbed in > the alumina in a distributed way, causing the LENR powder to be largely the > same temperature as the surrounding ceramic. I don't believe it is > necessary or probable that the core must be much higher temperature than > the shell. > > Can we refocus this thread into discussion about the construction of the > latest reactor? For example: > > - Why do we think the end caps are so big? Are they part of a lower > temperature insulated mounting system? > - Why do we think the 3-phase drive is used? > - What else? > > Bob Higgins > > On Sun, Oct 12, 2014 at 9:43 PM, Robert Lynn < > [email protected]> wrote: > >> 1% lithium in 1g fuel, so 0.01g, boils at 1342°C. At 1 bar,1342°C would >> fill about 180mL volume, reactor volume probably about 30-50mL so will be >> filled with lithium gas under pressure - operating as a heat-pipe to >> equalise pressure. >> >> I have just realised that we can probably infer the existence of an inner >> reactor vessel because we see helical wires or wire shadows of only one >> angle - we can't see both sides of wire helix through an open core because >> there is an inner core vessel in the way. I had thought there was no such >> vessel, so my conclusion about the wires being hotter no longer stands up. >> The wire temperatures are electrically controlled to alter the amount of >> radiative heat flux that leaves the inner vessel - a crude method of >> controlling heat flux that suggests great improvements in COP if better >> methods of heat flux control are employed (high temp coolant fluid or >> moveable insulating shields). >> >> That inner vessel must be crazy hot! around 300°C higher than the >> already hot outer wall in order to radiate the heat to the outer wall and >> hot wires; eg if Ø20mm outer wall is at 1200°C (approx max given revised >> COP of around 2 from temp reading that is obviously in error due to >> non-melting of inconel, though could be significantly lower) then an inner >> alumina tube of Ø12mm outer diameter radiating 1kW would need to be more >> than 1500°C surface temperature (Actually higher given hot wires >> surrounding it), so again it seems temperature within vessel must be up to >> range where nickel is melted and lithium is gas at 5-10bar. >> >> I wonder if that smaller hotter inner tube and translucence of outer >> alumina tube is what is screwing up the thermographic calorimetry? If the >> camera is picking up the inner tube at 300°C temp higher than the outer >> then the exterior tube temp might only be 1100°C and the COP could be a lot >> lower >> >>
