Simple New 'Differential Calorimetric' Reactor Design.

  • No transients, in fact no difference between control and test at all. It may be that dissolving the LiAlH4 in Hexane so that it coated the orther ingredients as it dried denatured it too much. I do have another set up where I can control the hydrogen pressure but haven't used it this time. What's in the tube (which gets flushed with hydrogen before sealing) stays in there. The only thing I do in these type of tests is put a little chip of magnesium right at the bottom of the tube with wadding between it and the fuel proper. This is to mop up any stray oxygen.


    I have a different batch of fuel brewing now, So many more tests planned, this is a simple and fast system.


    Attached is a picture of the steel 'variable pressure' fuel containers in an original Mk1 Reactor. These were sold, but I have another pair that can be used in the current apparatus. They are fitted with silver-brazed 4mm OD gas/vacuum pipes (also stainless) which thanks to the very poor thermal conductivity of stainless steel can be coupled up with high-temperature silicon-rubber tubing. This kind of tubing is ok for pressures between 1mB and 3.0Bar, but for higher pressures could be fitted with suitable connectors for up to 6Bar - 84psi.


    As you can see, the tubes fit into the 'hot cores' of the reactor, where they nudge up against a pair of thermocouples in the heart of the system. There is increased interest in monitoring Hydrogen pressure in fuel tubes, since this can be used to trigger reactions and also as the best indicator of the degree of hydrogen take-up (hydrogen loading) of the fuel.

  • Interesting photo; it's hard to believe that the tubing there would be capable of keeping the hydrogen sealed. (EDIT: I don't mean in a bad way)


    I previously made that question because according to certain theories the formation of compact hydrogen species (for example Hydrino, DDL, UDH, etc. etc.) can be accompanied by short-lived exothermic effects in addition of possibly a decrease in hydrogen pressure (a consequence of the phase transition of the hydrogen atoms). These can be of course also be the result of standard chemical reactions or plain absorption of hydrogen into the Ni powder, but the latter (especially) is supposed to be slightly endothermic and not very deep at pressures near atmospheric.


    Once these species are formed then a suitable impulse or some other sort of excitation would be needed to trigger nuclear reactions within it, but it's possible that (although not directly known if) very high temperatures may be capable of this too.


    So my point is, with all possible caveats, that anomalous short-lived fluctuations in temperature and pressure decrease may be a sign that a more substantial reaction is ready to get triggered. If you're not seeing anything at all then the system is probably inert. In some systems the trigger is also what causes the hydrogen to transition to a more active form, but it's not the case of these tubes, at least if you're only increasing temperatures monotonically.

  • For simple differential thermometry, consider wiring two thermocouples in series, with the polarity reversed. The output of the series string will then be proportional to the temperature difference between the two junctions. It is necessary to use a pair of thermocouples that are closely matched across the entire expected temperature range. as an alternative, the system can be calibrated with the two junctions at the same temperature, so the output vs temperature will give a calibration curve for post-correction of the data.


    For details, see http://www.nutechengineers.com/dtmwt.html

    There are at least two ways to get well-matched thermocouples. One is to pay the extra money to get matched pairs from the supplier, and the other is to make your own. Use from wire that came off the same roll, and preferably wire that came off immediately adjacent during unrolling.


    Making your own thermocouples is easy. For wire bigger than about 24 gauge, bare about 1/4 inch of the wire from the insulation. Give the bare wires about 1.5 to 2 full twists. Get your oxy-acetylene torch to a neutral flame and weld the wires into a bead. For small gauge wires, it takes less than one second, so slowly pass the wire through the flame without stopping. It takes some practice, but practice only uses about 1 cm per try.


    For wire smaller than about 20 gauge, I have had excellent success with a Variac (at least 5 amp rating). Run one of the Variac leads to a scratch pad. The scratch pad is a steel or copper or stainless steel plate about 5 cm X 5 cm X .3 cm thick with a hole drilled or tapped for the Variac lead. Bare and twist both ends of the thermocouple wires. Attach the other Variac lead to one end of the thermocouple (alligator clips work for this), and physically scratch the other end of the wires across the scratch pad. Try it several times and you will get a good feeling for the correct Variac setting for each size thermocouple wire. Attach a piece of tape as a pointer for each wire size. I have made good thermocouples with wire as small as 40 gauge with this technique. This might work with a voltage regulated power supply, but I have never tried it.


    Now go pat yourself on the back for saving money compared to buying pre-made thermocouples, but of course you have to have the acetylene torch and/or Variac. I've only made type K thermocouples this way, so I can't speak for the ability to make other types.

    Dan

  • The post above shows the two-channel H-Bridges in position, and the scope trace from the output of one channel. Nice clean square-wave AC 720-730 Hz, [email protected] per channel, channel temperatures matched to +/- 1C after 60 minutes from cold (849, 851C).


    I am going to have to reduce the number of turns or change to thicker wire for the heaters, btw, since while I have plenty of headroom to increase the current - the H Bridge will handle up to 10A - the max voltage into the H-Bridge is 25. And as you can see from the figures above, circa 120W per channel only gets me to 850C.

  • Alan, unless you are using some kind of temporal-expansion probes, it looks like your switching frequency is actually 724 Hz, not 724 kHz.


    In terms of B-field induction effects, the edge rate is what really matters, not the switching frequency.

  • That's correct, thanks for pointing it out. A typo I will amend :( . As you see btw, nice clean waveform good dV/Dt.

    Alan,


    As I understand it you want to investigate whether varying magnetic fields have some affect on your reaction rate.


    Two things:

    You'd expect the magnitude of such an effect to be prorpotional to the switching frequency, on the grounds that edges are additive. You can always propose more complex mechanisms where some metastable active state is enabled by an edge, but that must be less likely.


    Since this is hypothesised to be dB/dt related it must matter how fast is your edge, and you should characterise this to know what range of frequencies you are using. For that you probably need a scope trace some 100 X expanded...


    Finally - you seem to have a nicely engineered system which can be very sensitive. I'm wondering about the use of iron (if I remember rightly) as your control once you start introducing magnetic fields. The iron will interact significantly with the field. A non-ferromagnetic material would be better - even better still would be an insulator.


    Regards, THH

  • THHuxleynew


    Thank you for your input. I have always considered the importance of using materials with matched ferromagnetism. To that end I have controls based on equivalent weights of both plain Ni and Fe, powders sans hydrogen, of course. What would be the benefit of using a non-ferromagnetic material. as a control? I am not sure I understand that.


    As for the expanded scope traces, been there done that. :) Rising edge amazingly clean and vertical which is I suspect assisted by the relatively low capacitance/inductance of the heater coils and the fuel-tube combination. I think I will need to see what happens to the rising edge when I put the -obviously more inductive - steel tube fuel-holders in place in the cores.

  • I guess the challenge would be keeping all the particles electrically separated and preventing them from sintering, not an easy task. I asked because I tried searching some information about it and found that for the previously mentioned Fe-Ni material a frequency of about 1-2 kHz would have a skin depth in the range of the radius of the metal particles typically used in these experiments. Recalling that there have been suggestions in the past of frequencies along this range being used in more successful experiments I was wondering if there could be any benefit in matching the skin depth effect with particle size.


    But it's just a simple thought I had and any correlation with that piece information is likely coincidental.


    http://i.imgur.com/ttx6PRd.png

  • I think that Rossi's system certainly operates at around 1- 2kHz, plus sum and difference harmonic effects if more than one heater wire is used and they are 'out of synch'.


    To explain - The 3 separate 'phase controller' boxes visible in switch-gear cabinets in the notorious 'Stethoscope' shot from Doral are of a type I am familiar with, and they can each comfortably generate pseudo AC at up to 700Hz. Depending on how you organised things, 3 x 700 = 2100Hz with harmonics above and below is thus possible. There may well be something in this idea, which is why I built the H-bridges, which are happy up to (probably) 5 kHz if required.

  • I remember about that; if I'm correct the idea was that the particles would start moving under the influence of the rotating magnetic field, as in an electric motor. I'm not sure if that would also work with a single coil/phase however. For what I proposed on the other hand the particles would preferably have to be embedded in a dielectric material, which is not what gets typically done in these replications. This idea isn't new: for example I believe that Brian Ahern in his rejected patent had something similar, but with nanoparticles embedded in zirconia. Water was also used in some embodiments.


    EDIT: here's Brian Ahern's abandoned patent application, linked here mainly in reference to the dielectric matrix as in practice he did something different than these replications:

    US 20110233061 A1 - Amplification of energetic reactions

  • Hi, I hope you don't mind me asking this but would you say it's comparable to the DSC PT1000? That's the differential calorimeter we've got in our lab and I'm never quite sure how exact its results are. Also, would you be interested in developing a software that digitizes all the data?

  • snotty


    Welcome! Comparable is a big word. I think the main difference in use would be that this will take a sample up to 10mm in diameter (though preferably less) and 120mm long. Most commercial DSC's only take milligrams.


    Now the calibration phase is coming to an end. both channels are repeatedly and reliably within 1C and 1W of supplied pure DC electrical heat of each other at 1050C. As there is no direct thermal or electrical contact between them I think this is remarkable. 1W makes a 7C difference btw, even at that temperature, though I would not claim that such a simple device is accurate to the 0.1% that this suggests. After all, this is a $500 machine, not a $50k one. IW btw is around 0.6% of the electrical input per channel at 1050c.


    Next step is to push the calibration temperature comparison up to 1250. Beyond that there is no point while I'm using inexpensive k-type thermocouples, they usually die!


    Thank you for your offer of help with sofware design btw, but our asses are clad on that one at least. We (http://www.lookingforheat.com) actually build and sell data loggers to cope with any reasonable requirement. I haven't been using them for calibration but that is simply because there can be many stops and starts involving finding the power inputs