I just suggested the following as the construction of the latest hotCat to MFMP:
Here is a section drawing of the end of the new hotCat as I see it ( https://drive.google.com/file/d/0B5Pc25a4cOM2WXBNRjE2bDVVT1U/view?usp=sharing ). I believe IH would have used as many off-the-shelf components as possible. I think the outer 2cm tube is a custom cast tube that used a 3/4" threaded rod as the OD and something like a 5/8" rod as the interior for the cast. For replications, a standard Coorstek tube without the ridges could be used to start - they probably did this themselves before going to the custom cast tube. So, here is the Coorstek catalog of their standard cast and extruded tubes ( http://www.coorstek.com/resource-library/library/8510-1031_tubes_rods.pdf ). The fillers may be high alumina fillers like those from Vitcast: http://www.vitcas.com/insulating-castable ; I believe the large tubes on the end to be thermally insulating supports for the hot central 2 cm tube. Referencing the 4mm bore called out in the report, it means that the core tube for the hotCat is 4mm ID. This will not open to a bigger tube - they are not made that way - it is 4mm uniform all the way through. I believe the central tube is a 4mm ID cast tube with a closed end (probably the rounded one). I will go out on a limb and say that I believe the inside of this tube is probably sealed with an alpha alumina coating ( http://www.azom.com/article.aspx?ArticleID=3560 ) and fired. Then they probably created a Ni-Fe2O3 powder slurry with an organic binder such as PVA and coated the inside of this central tube with the powder. Then they fired this at about 800C with the tube open to burn out the PVA binder and sinter the Ni to the alumina tube inner wall. The heater coils are wrapped around the OD of the center tube, with the wires leads insulated with alumina beads, and the wires are cemented to this tube with something like MTI's high alumina adhesive ( http://www.mtixtl.com/1650c3000fhi-purityaluminaadhesiveforbondingandrepairinghightemperaturefurnace… <http://www.mtixtl.com/1650c3000fhi-purityaluminaadhesiveforbondingandrepairinghightemperaturefurnacequart.aspx%C2%A0>;). This center tube assembly is probably then fired in an oven to cure the glue which should completely coat the wire. Then I believe this tube assembly is coated with something like the Vitcast 1400 INS-H and pushed into the outer long tube and the assembly is fired again in an oven. Then the ends are sort of cast on by placing the large alumina rings over the tube ends and filling with something like the Vitcast 1200 INS as an insulating support. I think the plug for the center tube is made from a 1 cm piece of Coorstek 0.156" OD tube that has a 0.94" ID which is used to cement in a sheathed thermocouple. You would have to be very careful to pick a thermocouple type that is appropriate for up to 1500C. The thermocouple sheath is cemented into the plug with something like the MTI adhesive. If you go through the thought experiment of constructing a hotCat of your own, it will give you some insight into what the IH team may have done. Here are some of my other thoughts: - I believe the coils are 3-phase to create a moving magnetic field to circulate an interior plasma when it emerges. - I believe the active powder is sintered onto the inside of the central tube - almost like a catalytic converter. - I think what Rossi added in the beginning is primarily hydride - maybe some Ni powder was added for obfuscation. You can't take this for "starting material" for comparison to an ash (which they didn't get either). It is probably just a consumable + obfuscation. - I think what came out at the end of the experiment (thought to be ash) was some left over loose slag and debris - it is not representative of the active material which is sintered to the inside of the central tube. This debris cannot be used as representative of active powder ash because the real active powder is still inside the central tube. - The heater wires and the termination wires are probably different materials and the actual heater wire coils are fully encapsulated with a high alumina cement. Maybe the ends are terminated in inconel for interconnection. Bob Higgins
