Activated alumina is a porous, granular substance that is used as a substrate for catalysts and as an adsorbent for removing water from gases and liquids. Smelter-grade alumina accounts for 90 percent of all alumina produced; it is transported to aluminum plants, where it is electrolyzed into aluminum metal. Calcined alumina is *made into a variety of ceramic products*, including *spark-plug insulators*, integrated-circuit packages, bone and dental implants, laboratory ware, sandpaper grits and grinding wheels, and refractory linings for industrial furnaces. These products exhibit the properties for which alumina is well known, including *low electric conductivity*, *resistance to chemical attack*, *high strength*, *extreme hardness* (9 on the Mohs hardness scale, the highest rating being 10), and *high melting point (approximately 2,050 °C, or 3,700 °F)*.
Sounds like a good choice to me. On Sun, Oct 12, 2014 at 1:41 PM, Axil Axil <[email protected]> wrote: > This method of sealing and the fact that the reactor is not purged of air > means that the hydrogen is bound in a solid as a hydride at all times to > metals in the reactor most likely aluminum or lithium. > > On Sun, Oct 12, 2014 at 1:35 PM, Robert Lynn < > [email protected]> wrote: > >> if there was an inner metal cylinder to contain reactants (particularly >> insanely leak-prone hydrogen at high temperatures) then it would be sealed >> by welding not half assed approaches like alumina glue. Until you have >> worked with hydrogen (I worked with stirling engines containing hydrogen) >> it is hard to appreciate just how disrespectful it is of things like >> hermetically sealed containers and thin walled materials of all types. >> Anyone with similar experience would find the idea of such a small reactor >> with low volume small fuel charge and large thin wall operating for a month >> at 12-1400°C while retaining hydrogen fuel totally unbelievable. >> >> Also alkali metals are nasty on all metals that I am aware of at high >> temperatures - particularly in heat pipe type applications like this - pure >> lithium condenses on cooler wall surfaces, instantly dissolving metal atoms >> from the surface and washing them away to the hot zone where the lithium is >> evaporated. This leads to fast corrosion/eating away of basically all >> metals as they are all slightly soluble in lithium, made worse by elevated >> temperatures. This reactor is a lithium heat pipe, with hot nickel powder >> heat source at the bottom of the tube and lithium washing down the walls >> continually to deposit dissolved atoms at the bottom evaporation zone. >> >> On 13 October 2014 01:18, Stefan Israelsson Tampe < >> [email protected]> wrote: >> >>> Robert I think you make good points, not sure what the inner cylinder is >>> made of and I guess that if it is metal it has to be thin in order >>> to not show up on the weight. There is also the possiblity that eddi >>> current's heat the cyllinder at high temps but then can we keep the >>> wires cold. Also, this is speculative, but we really don't know the >>> inner process if this thing works, can there be a local magnetic field due >>> to the reaction, the thing is the only way I can figure out that the >>> nuclear process is happening without radiation is that the there is a >>> deallocated >>> electron squeezed between the reactants in the nuclear process that >>> mediates the energy and momentum to the outer metal in the reaction in stead >>> of releasing radiation, so there is a movement in the electron, if this >>> is somewhat synchronized locally we might get some magnetics to show up. >>> This >>> is only speculating, but I think that we should be careful whith what we >>> don't know, you seam to find good arguments against inductive heating, and >>> this might leave us with resistive heating and a good evidence that the >>> core is hot due to the reaction and not because of resistive heating. >>> >>> On Sun, Oct 12, 2014 at 6:55 PM, Robert Lynn < >>> [email protected]> wrote: >>> >>>> far above curie limit for Ni, magnetic fields won't move powder >>>> magnetically, only ions, but temps are too low for significant Li or H ions >>>> to exist, and no ionising radiation sources in evidence. >>>> >>>> On 13 October 2014 00:49, Stefan Israelsson Tampe < >>>> [email protected]> wrote: >>>> >>>>> Yes but in that case the core can be hotter then the cables. We don't >>>>> know about the powder, and the changes of magnetic fields inside the core >>>>> could stir the powder around and by changing that behavior you might end >>>>> up >>>>> controlling the reaction rate. Also inductive heating of an inner >>>>> containing cylinder does produce a fast response to the actual cylinder >>>>> which controls the heat radiative environment in there. >>>>> >>>>> On Sun, Oct 12, 2014 at 6:41 PM, Robert Lynn < >>>>> [email protected]> wrote: >>>>> >>>>>> inductive heating only works on conductive materials with sufficient >>>>>> thickness/area through which the changing magnetic flux passes to allow >>>>>> eddy currents to form. With 150Hz pulses Nickel particles of tiny scale >>>>>> would not be affected (like thin motor laminates) - it would only work to >>>>>> heat a secondary metal body that could then heat via radiation (very >>>>>> inefficient, and of no practical benefit). >>>>>> >>>>>> On 13 October 2014 00:35, Stefan Israelsson Tampe < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> How do we know that iti s resistive heating that is taking place? >>>>>>> Bob Greenyer at MFMP sugested that it is an inductive heater this means >>>>>>> that the wires >>>>>>> get a bit cooler then the heated core. >>>>>>> >>>>>>> On Sun, Oct 12, 2014 at 6:24 PM, Robert Lynn < >>>>>>> [email protected]> wrote: >>>>>>> >>>>>>>> Fig 12b. page 26. Only just notice that they say they are >>>>>>>> "inconel" resistance wires. But how can the resistor wire, external >>>>>>>> to the >>>>>>>> reactor, glow more brightly than the reactor itself (implying it is >>>>>>>> hotter)? Also if the reactor external surface is at 1250-1410°C, then >>>>>>>> on >>>>>>>> top of the 30-50°C temperature drop through the walls the resistive >>>>>>>> wire >>>>>>>> would have to be even hotter (up towards 1500°C) in order to be able >>>>>>>> to >>>>>>>> radiate the 900W! And there are no "inconel" metal wires that can >>>>>>>> survive >>>>>>>> such temperatures in air for a month. >>>>>>>> >>>>>>>> http://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html >>>>>>>> >>>>>>>> There is also a mistake in their discussion for these figures, the >>>>>>>> metal resistors within the reactor would necessarily have to be hotter >>>>>>>> than >>>>>>>> the reactor itself if they are to be able to output heat into the >>>>>>>> reactor. >>>>>>>> But then again at >1450°C inconel resistance wires would have turned >>>>>>>> into >>>>>>>> puddles anyway. >>>>>>>> >>>>>>>> The 2mm high fins on the outside, subjected to convective air >>>>>>>> cooling would be 30-50°C colder than the base of the fins due to the >>>>>>>> longer >>>>>>>> conduction path and hence greater temperature drop through the alumina. >>>>>>>> And that should influence the thermography to under-read, but also >>>>>>>> means >>>>>>>> the temperature within the reactor would have to be even higher to >>>>>>>> create >>>>>>>> 1400°C average surface temperature. >>>>>>>> >>>>>>>> So this proves that the thermographic temperature readings are off >>>>>>>> by a very long way - at least 150-200°C too high if inconel wires that >>>>>>>> max-out at about 1300-1350°C were to have survived for a month. We now >>>>>>>> know there is a huge error, we just don't know the source of the >>>>>>>> error, or >>>>>>>> how big the error is. But eg 1210°C vs 1410°C would drop power output >>>>>>>> by >>>>>>>> 40% from that claimed so that the COP would be <2. >>>>>>>> >>>>>>>> With the existence of such a huge error of unknown source the >>>>>>>> claims of power output cannot not be trusted at all. >>>>>>>> >>>>>>>> On the upside, it does however mean that the nickel was not melted, >>>>>>>> and lithium vapour pressure was a lot lower. >>>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
