sounds like the Les Case system I have now. Tube in a tube. It can get messy (and costly- fluid costs) if you develop leak somewhere. When I was running it, I needed to run at a bout 60ml/ min to keep the delta T DOWN. The problem is if you have the delta T too high the properties of the oil (heat cap., viscosity,...) start to confuse things.----- at least for me. In the Case system, you had H (or D) flowing through the smaller sample tube at the center. But it was fairly robust and had about 200 ml of sample in the inner tube. (Note: Case reduced/produced the material in situ from an metal organic) It looks like he was running at around 200-300 C) D2
Date: Thu, 25 Jul 2013 21:57:16 -0500 From: [email protected] To: [email protected] Subject: [Vo]:Kitamura much improved Kitamura et al. have been working on gas loaded Pd and Ni for some time, originally in a replication of Arata's Zr+Pd alloy. Kitamura's experiment looks much better to me than it did last year. They finally made a precision flowmeter. It holds a much larger sample of powder. It is about time they scaled up the sample size. It can be run at high temperature with reasonable accuracy. I think they are now getting more heat from the Ni alloys than Pd. They get 20 to 30 W from Ni. It only works at high temperatures, as I recall around 300 deg C. One lesson from the last few years is that if you want to make Ni work, you need a high temperature. I have a few concerns about the calorimetry, but that is probably because I am unfamiliar with some aspects of it, to wit: They are using oil instead of water as the working fluid. It is a good choice for such high temperatures, but I have not used it myself so I can't judge. I am a little concerned about a curve they showed from the manufacturer of heat capacity and viscosity at different temperatures. It varies a great deal. You have to trust the manufacturer on this. The flow rate is only 20 ml/min. That would be too slow with water. I don't know about oil. They measure the temperature on the outside of a small copper pipe. I guess that should work but I don't see why they did not use a T. Again . . . maybe that is not a good idea with oil? I have heard the stuff leaks out of seals, pumps and Ts. On the plus side: They used several other temperature sensors on the cell wall. They were well calibrated and they all agree on the power levels. The recovery rate is 88% as I recall. That's high. The whole thing is insulated in a vacuum jacket (like a giant Dewar). The calibration seems rock steady, and the calibration curve is linear. These people have been dealing with this for a while so they have probably answered all concerns. McKubre asked Kitamura to estimate the error as a percent of input but Kitamura could not. Perhaps he misunderstood the question. McKubre said it was a "good job" despite this. U. Missouri intends to upload the slides from this conference, with permission from the authors. I expect Kitamura will grant permission. This is one you should look at. - Jed
