On Mon, Jul 18, 2011 at 9:46 AM, Jed Rothwell <[email protected]> wrote:
> Abd ul-Rahman Lomax wrote: > > Jed, this is dead wrong. This is obvious. Suppose you have *almost* full >> vaporization, not all the water is boiling, so water level in the E-Cat will >> rise. >> > Almost full vaporization is a degree or two below boiling. That's my point. > > > > Eventually, some will spill out. What is the temperature of this water? >> It's the same temperature as the vapor before! No change in temperature will >> occur. >> > > No, is it significantly cooler, unless it is boiling vigorously, and it > wouldn't be. > > > Basically, if there is constant heat, flow rate can be varied over a >> considerable range and the temperature will remain constant. As long as the >> chamber doesn't run dry, temperature will be nailed to the boiling point of >> water. And as long as the flow rate is low enough that *some water boils*, >> the temperature will remain the same. >> > > It would cool because cold water would be coming in replacing the boiling > water which flows out. As you yourself say, it would be impossible to hold > it right at the knife edge just above boiling, with just enough heat to keep > it boiling while hot water flows out. > > When you have boiling water inside plus some headspace filled with steam > (like a mostly-full teapot), then you have some space to work with and you > can increase or decrease the power to lower or raise the water level. This > is what you do when boiling vegetables. When it is overflowing with a > constant stream of cold water coming in, you can't do that. > > This is the result you see in the data from several of the high-temperature > flow calorimeters used in Italian experiments. The temperature tends to hang > around just below boiling, because it is overflowing. > > Close-to-boiling is a difficult domain for calorimetry. If you insist on > doing this, I recommend reflux calorimetry. It is also better to increase > the flow rate, which Rossi has done on some occasions. These other tests > prove that the steam tests were right, as I said -- and as Rossi and Levi > said. > I don't even think you believe the nonsense you write. You just spew words that sound sorta right so that you can make a pretence of continuing to support the unsupportable. Then you put your fingers in your ears when people (on your side) try to set you straight. Anything between 600W and 5 kW (for Krivit's ecat) produces a mixture of steam and boiling water at the boiling point. That's not a knife edge. What you (pretend to) claim -- that it is all boiled all the time giving a completely stable power output -- *that's* a knife edge. This is really so basic and simple, that I don't believe an accomplished person such as yourself, doesn't understand it. It must be a pretence. > > At Defkalion they leave it in liquid state at all times, which is better in > many ways. > Unfortunately all the better tests are hidden from the public. Another certain technique is to turn off the power and have it run in heat > after death. Julian Brown reported that Rossi turned off the input power for > "a while." That's not heat after death; that's thermal mass. Say it takes 300C in the ecat to just boil the water, and 1500C to boil all the water. At any temperature in between the output is gonna be at the boiling point. Then if you goose it for a while to bring the temp up to 400C or so, it will take a little while to cool off to 300. And in that time the temperature will stay at the boiling point. Simple. > I asked him how long is a while? How many minutes and seconds? He did not > know, but he estimated 2 minutes. It is a shame he did not use a video > camera or write down the duration. It is hard to estimate, but I think > boiling should have stopped, and the temperature should have fallen rapidly > after a minute or so. I say this because the specific heat of iron and > copper is about 10 times lower than water so there is not much thermal mass, > and an immense amount of energy is removed by boiling. Look at how slow it heats up in the early stage, and how slow it cools off (below boiling) in the January demo to get an idea of the thermal mass. The temperature range while the temperature is at boiling point is much larger than the 80C or so in the heating up and cooling off phases. So, the time to cool off could easily be longer (up to 7 times longer) depending on how close to complete vaporization you start at. So this "heat after death" proves nothing. > Boiling stops quickly when you turn off the flame on a gas stove. > Not so quickly with an electric stove though. > > If it continues boiling for 5 minutes without input I am sure that would be > proof of anomalous heat. Not a chance. That's a fraction of the time it takes to cool from boiling to ambient. So the power would have to start from much less than double the boiling onset power, and still far away from complete vaporization to explain it with thermal mass. > I did a test boiling 2 L of water the other day in a pot with a glass cover > and a K-type thermocouple. Less than a minute after cutting off the heat the > boiling stopped, and 5 min. later the water temperature was down several > degrees and the headspace down ~5 deg C. That was the case even though the > metal pot was pretty heavy and of course much hotter than boiling > temperature. > If you start from a power just above the boiling onset, then it does not take long. What if you could double the input power beyond what it takes to start the boiling. (That would be difficult to identify.) Then it would take longer. And if you wrapped it in insulation and used a much larger ratio of pot to water, you might have a relevant comparison. But what to expect from someone who learns his physics by making pasta, or from other people who make pasta? > > It is a shame Brown did not observe heat after death for 5 or 10 minutes. > It would be so easy to prove anomalous heat, and yet it is always a shame that it's not done. Rossi can't be too clever.
