Durable reactor with replaceable core

1st Official Post

    Seeing the issues that continue with Nichrome / Kanthal wired ceramic cores. I suggest we try to design and build a more durable reactor that allows replacement and/or renovation of the core, with relatively little maintenance on the "furnace" portion. At stage of replications it may be time, since I see a lot of effort in building the heating elements and whole reactors over and over. Combined with the great difficulty in changing the formulation within the reactor core itself.


    Here is a preliminary vision of how both issues might be addressed. Using quartz halogen lamps (they are used in movie projectors and in ceramic cooktop stoves today, as well as in lighting). An array of such lamps could surround concentrically a central reactor core made of aluminum oxide (perhaps with a layer of refractory pigment such as carbon or zirconium carbide to enhance absorption of thermal photons.... or the central core could be essentially transparent (pure optical apphire for example, big money I'm sure) to a broad range of wavelengths, to increase transmission to the internal contents.


    Clearly such lamp filaments can be driven to much higher heat than Nichrome / Kanthal. Actually about 3 times the temperature. Especially with the halogen+xenon gases in the bulb, which prevent the filament from sublimating, allow much higher color temperature exceeding 4000 K with long life, or at lower temperatures (read more IR) with very long life. The latter IR rich bulbs would best be replacement types for a ceramic cooktop stove-- in halogen bulbs the content of halogen is changed depending on the tungsten filament operating temperatures.


    To direct the radiant energy toward the central core, I suggest initially white, temperature tolerant ceramic, such as pyroceram surrounding the circle of lamps. However, the lack of strong conductivity might be an issue there since the lamps themselves can only tolerate so much heat (this tolerance is far higher than ordinary light bulbs, but probably not above a dull red for the housing... just a guess). Another more ideal reflector might be a heat tolerant metal, either stainless or Inconel, either of which could be fan or liquid cooled. For optimum reflection, an idealized future version might have a rhodium or other precious metal coating facing the lamps and the core --- I recall that these coating are very rugged, heat and corrosion resistant, and I am fairly certain they are broad band. These reflective coatings have been seen in the xenon discharge lamps used on larger theatre projectors and in heliocopter lights. Such a coating is fairly thin (microns), so not as expensive as one might imagine.


    So, a concentric to the core outer cylinder with a substantial number of quartz/halogen lamps arrayed around the inside. These lamps would be shielded so as not to heat one another, with the open side facing inward to the core. The lamps could be selected so that their length fully illuminated the full length of the "active" portion of the core. The core would extend beyond each end of the reactor furnace out to a distance to allow relatively cool connections, as we presently see in some of the replication designs. The outer portion, if designed and built well, should allow hundreds of 36 hour trials without so much as an occasional burned out bulb. My hope then would be that the excellent efforts of the replicators and other more exploratory efforts could be concentrated on the active material rather than on the "furnace" portion.


    I welcome any and all comments. I hope we can successfully get somewhere with newer ideas.


    Thanks,
    Longview

    Why not have the quartz heating tubes in a planar array and place the reactor tube at the focus of a parabolic reflector? That should focus the IR onto the reactor without having to have the quartz tubes in physical contact.


    Other option which is a little more tricky is to have a quartz heater tube in the centre and have a fuel cylinder surrounding it. Then all the IR radiated from the tube should be absorbed by the fuel canister. Unfortunately that would require a dual cylinder shaped fuel canister.


    There was some discussion that either electric or magnetic fields had some part in generating the reaction, not just heat. I haven't seen any answer one way or the other but you still might need a coil to generate the field.

    Quote from GlowFish

    Why not have the quartz heating tubes in a planar array and place the reactor tube at the focus of a parabolic reflector? That should focus the IR onto the reactor without having to have the quartz tubes in physical contact.


    There was some discussion that either electric or magnetic fields had some part in generating the reaction, not just heat. I haven't seen any answer one way or the other but you still might need a coil to generate the fields.


    I had imagined that the quartz lamps would be up to a cm from each other, allowing a shield between them. But, I like your idea, since it makes the whole construction quite easy. I guess a planar array would still have to have spot welded shields to keep the tubes from heating one another too much, particularly if the array were fairly dense with bulbs. The parabola would be very easy to make, since the focus is a line rather than a point, the paraboloidal cylinder is the form needed in that case. The whole thing might look like a flat plate on which the thing could stand, with the wiring and any coolants and gas connections coming in a the bottom "straight" sides. The paraboloid would form sort of a roof and the sides can be just straight polished stainless sheet. The reactor core would be inserted through holes in the straight sides at the exact focus of the paraboloid.


    I have always been wary of having completely unregulated variables in a "witches brew" type of experiment. The role or lack of role for the magnetic, electrostatic and variations on them (chopping dimmers etc) has been something that needs to be controllable. With a "durable reactor" those other variables can be added and manipulated much more easily-- with the bonus that we get away from one or more "unknowns". Wires can be attached via the cool outside, and conduct via ceramic ring standoffs into the core, and can be quite readily changed in configuration. Once the fields can be manipulated as intentional variables, we're on our way to understanding their role, if any. Further, we than can optimize the level, rise-time, polarity, frequency etc. It surely is not likely that 50 or 60 Hz is the "perfect" number, or that some feeble switching noise from a dimmer is the "final answer", such serendipity rarely if ever happens.


    Thanks for your interest, Glowfish


    Longview

    Much of the replication work is intended to imitate the Lugano experiment, and there is a highly COP-o-centric thinking, as one want the possibility to easilly compute input power and compare to the output. But for the recent experiments, where the output energy is not really evaluated at all, but only a differential is of interest, that is the difference between the dummy/calibration run and the active run in terms of measured temperature, then the input power is simply a book keeping index, and not important on absolute values.


    What I mean with this is, that any ol' form of heating the reactor - no matter how inefficient it is, as long as it is controlled and can be same for the calibration run as for the active run - would be OK from an experimental perspective.


    So sure, why not use a truckload of photons instead. It will be more expensive than a sturdy coil, and it would be worth trying. Deviating from the dog-bone and Lugano setup, there are other reasonable geometries that can be explored, and ways to deploy EM fields. The question is then if this is a replication of Lugano.


    In my thinking, making a successfull run first with something allready shown to give result and changing setup later is a good approach. Also consider the reason WHY the 0.7mm Kanthal A1 wire would snap - granted that each turn in the coil is duely seperated - could be due to a surge in heat in the generator, maybe the solution is to go with Kanthal APM (slightly better thermal limit) and with a sturdier thickness, say 1mm. Or why not with the SiC adverticed by MFMP.


    In terms of easy deployment and maintainance, having a SS tube with the active fuel inserted into the alumina reactor goes a long way to improve "rationality" in this. The reactor stays the same, you just deploy next experiment with a new SS tube.


    So my 25 cent worth would be to stick with current paradigm, and when some real measure of success is found, expand and elaborate on geometries, energy souorces etc.



    ?( BTW what happened to Brian Ahern and his oven experiment? The silence indicate 1 of 3 possibilities: 1. He has not yet started. 2. He succeeded and is now silently continuing, seeking fame and fortune. 3. He failed utterly and does not feel like discussing it.


    One fourth alternative is that the info is out there, and I just did not pay enough attention. X/

    Using a SS tube, could even be implemented in a paraboloidal setup. One drawback of SS tube is that it will conduct the heat and radiate it in all directions, including down the tube and out into the adjacent "connection" zones. Further SS can easily short windings itself, so a layer of refractory insulation would be needed.


    Was there some idea of two concentric SS tubes with the windings between them, that is on the inner tube, and surrounded by the outer tube?


    But since the SS tube itself can then short the windings... then one has to add two concentric refractory tubes or ceramic fabric to surround the winding layer. Now we are still at coil winding to winding issues, and possible expansion differentials, if they might be important. A coil of any alloy in air is likely to suffer some surface oxidation, so the whole thing should ideally be in an inert atmosphere or a partial vacuum with inert gas... getting us closer the a quartz / xenon / halogen lamp, but with only a fraction of the temperature capabilities.


    A nicely oxidized SS or Inconel tube at the focus of a paraboloidal, or concentric setup... no coils, no layers, if one thnks they can run without ceramic, or the ceramic inside the metal tube essentially for support. With something like that one might be able to make a complete changeout in just a matter of a few minutes, by sliding out the old ceramic and sliding in the new and resecuring the gas or whatever other connections.


    Another issue is that SS tube is not at all a transducer of radio frequency, microwave, light, UV or x-rays. Whereas the ceramic can often transmit some of those fairly well. A metallic electrical conductor can be a decent microwave waveguide, although SS is probably good only for a very short length in that regards since it is a relatively poor electrical conductor. So microwave energy could be pumped in from the end with a conducting waveguide or coaxial cable, then essentially shorted / terminated within the reactor. Diameter and wavelength become important in that scenario. One would want the energy to be absorbed in the reactor rather than reflected back to the klystron, magenetron or whatever generator.


    Speaking of a possible "best" for transmitting radiant photons at a focus: I see that Saint-Gobain out of Milford NH in the US has sapphire tubes of sufficient diameter and length for any of our applications.


    http://www.crystals.saint-goba…/Sapphire_Tubes_Rods.aspx


    Maximum temperature approaching the 2000 oC MP, extreme chemical resistance, including fluorine gas, High UV, visible and IR transmission. The tubes are available in the "as grown" unground form, which I am sure is much less expensive than the diamond lapped, optically perfected product. I guess I should mention here that sapphire is the monocrystalline form of Al2O3, which is also the content of sintered alumina ceramic. So, for most purposes, other than transparency, high grade alumina is likely to be a match for sapphire.


    But, coming back to what may be affordable, I see that GE has for decades made transparent alumina, originally used in their "Lucalox" bulbs --that is the inner bulb in arc based lamps now being phased out in streetlamp use after a 50 year successful run. Apparently that transparent ceramic material is now largely off patent and may be more widely marketed. See "transparent ceramics" in the "never to be trusted for controversial information" online encyclopedia.


    Thanks as before for your interest FreeThinker,


    Longview

    Some time ago, when beginning to draw up plans for reactor heated by three to four quartz lamps, I hesitated for two reasons:


    1. Concern that the lamps would fail in the high heat.
    2. Deviation from the imitated experiment.


    Nevertheless, it seems worth pursuing.


    Problematically, it may be that hotspots would still develop in a lamp heated system.


    If only we understood the mechanism(s) behind hotspot development. This thought has recently dominated my nightly dreams.

    Quote from me356

    I think that SiC element is step forward.
    Replacing heating wire makes construction much easier.


    I guess that a SiC element can even replace ceramic tube.


    Looking at the Cole-Parmer "Nabertherm" tube furnace give a maximum operating temperature of 1500 C. Seems good enough for the foreseeable future. I also see a Farhenheit number that converts out to 1550 degrees C (possibly the absolute maximum that Nabertherm left as a margin of safety in specifying 1500. Anyway, it is good news.


    http://kanthal.com/en/products…carbide-heating-elements/


    I see at this Kanthal site (above) that their maximum temp is 1625 C. It keeps getting better!


    And at another Kanthal page I see that in air the MoSi2 type heaters good to 1850 degrees C. That should be enough.
    Curiously the rating in hydrogen in down in the 1200 C range.... so no direct heating with that element at least.

    Perhaps many have seen this: an extensive list of values and the references for physical parameters of SiC.


    http://www.ioffe.ru/SVA/NSM/Semicond/SiC/basic.html


    It is interesting and informative. I notice that not one of the parameters for increased mass of electrons is over one. Perhaps that might signal a good omen for reliabilty in strong LENR environments, that is if W-L-S are right. Essentially SiC might not be capable of providing "heavy electrons" hence no ULM neutrons, so SiC itself should not degrade by isotopic and elemental transmutations :nuke: .


    {After the Lipinski UGC patent app., I have a lot of doubt about the role of heavy electrons, anyway.]

    Looking to the future a bit. The heater elements made of SiC or perhaps the ones of MoSi2 could be used in a Durable Reactor. One configuration might have the linear elements arrayed concentrically around and parallel to the core. A core of sintered alumina, capable of 2000 C still seems good, due to its ruggedness and chemical inertness and possible translucency (see earlier post about sapphire and alumina). The MoSi2 may already be available as a coil of modest diameter, judging from the few that are pictured at the Kanthal website. Appropriate high temperature reflectors and insulation could complete the picture. The main idea there being to make sure that the energy input is not so high that it makes it difficult to reach a credible COP.

    Quote from me356

    On the other hand, it is possible that normal resistor wire is needed for LENR.
    It is likely that SiC elements can't produce similar EM field.


    Parallel conductors having an high amp running through them give rise to an electro magnetic force trying to pull the together inducing stress in the conductors. Also when heated there is a coefficient of expansion that will expand the metal with increased temperature (very small, but still). I surmise that the same goes for these kanthal coils.


    Have you tried to apply the same ampere to the coil as is, without the reactor, to see if it can handle that stress? That in itself might be instructive.


    In your reactor the coil plastered with Al203 mortar (or similar) leaving less room for these expansions and compressions. Possibly it could be useful to have the coil loose, protected by an outer alumina shell (like MFMP dogbone in Lugano?), but so as to be able to compress/expand as the heat and current rise. I will go that way in my own experiments, whenever I get ready to "go".


    :lenr:

    • Official Post

    Did you get to do any experiments?


    Quote from FreethinkerLenr2

    Parallel conductors having an high amp running through them give rise to an electro magnetic force trying to pull the together inducing stress in the conductors. Also when heated there is a coefficient of expansion that will expand the metal with increased temperature (very small, but still). I surmise that the same goes for these kanthal coils.


    Have you tried to apply the same ampere to the coil as is, without the reactor, to see if it can handle that stress? That in itself might be instructive.


    In your reactor the coil plastered with Al203 mortar (or similar) leaving less room for these expansions and compressions. Possibly it could be useful to have the coil loose, protected by an outer alumina shell (like MFMP dogbone in Lugano?), but so as to be able to compress/expand as the heat and current rise. I will go that way in my own experiments, whenever I get ready to "go".


    I hadn't seen this ancient thread before, but it seems to parallel the thought processes behind our design for the 'Model T' reactor at lookingforheat. In actual fact using 0.9mm diameter Kanthal wire we seem to have very little problem with either expansion effects or inductive forces 'collapsing' the coils together while under power at up to 60V 10A AC. We use a coil tightly wrapped around the outside of a Quartz tube which is in turn a good fit into a bored hole in an Alumina foam. Coil life can easily extend beyond 100 hours. Biggest problem is that when using the replaceable core system in its simplest form you cannot easily run samples in a controlled atmosphere but depend on the atmosphere in the fuel core when it is sealed. We have ways around the problem now, but as ever more choice means more complexity, as shown in the photos on our website.

    • Official Post

    I have tried this. Actually there seems to be some confusion over the conductivity issue- I have recently seen a paper where the conductivity of alumina ceramics goes DOWN with increasing temperature. But that is not my experience so far.


    What I did was put a stainless wire electrode (in the form of a small coil (in intimate contact with the fuel) inside the ceramic fuel core, and wrap a ground connection coil around the outside. I then coupled it up to a lab-grade 3000V supply. There was zero conductivity through the tube wall until we got to 500C (using external heat) and then the current gradually went up until the system was pulling 3 watts. The HT supply gave up at this point, and the current dropped to about 30mA at 1000V. This was a pure glow discharge inside the core- which I proved by reversing the polarity-which gave zero current flow.


    The big problem with using the method you suggest is supplying the initial heat - conductivity is so low that it would need a big mother of a PSU to supply it. However, I have just laid on 400V 3-phase in the LFH lab, so we might have a little more headroom in the voltage department to play with.

    Quote from Alan Smith

    I wonder if Silicon Carbide would work?


    MFMP's "Bang!" experiment in late 2015 used a silicon carbide heater made as a sample for Bob Greenyer by a company in India, I believe. It has the capability of very high temperature and long life, but it is bulky and fragile. Of course, when the experiment ruptured, the SiC heater was shattered. But, it was clear that SiC works and doesn't rely on the conductivity existing only when the ceramic is hot.


    In these ceramic heaters, one of the core difficulties is the electrical contact. I believe the SiC heater MFMP used had silver paint for the contact with a compression contact to get to Cu wires. In ceramics with conductivity only at high temperature, you would have to design your contact such that it was cool enough that the contact metal didn't melt, but hot enough that there was conductivity in the ceramic.

    These materials require a "soft start" circuit to limit current until the resistance increases with temperature. These are not that complex to make, but the current handling capacity of the circuit needs to be adequate in case of failure (SSRs often fail closed for example).


    New (recent) model cars actually limit the alternator turn on with soft start cirtcuits to avoid loading the cold engine excessively (increasing emissions) and prevent squealing/slipping of cold drive belts, since the alternator is a significant horsepower load on an engine, and can exceed 10 hp at full output in high amperage designs typical of new cars.

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