On Fri, Jun 24, 2011 at 1:56 PM, Jed Rothwell <[email protected]> wrote:
> ** > Joshua Cude wrote: > > If it was overflowing that would be obvious from the temperature. >> > > How? If part of the water was converted to steam, then the water/steam > mixture would be at 100C. > > > With this flow configuration, in my experience it would around ~95°C as > soon as the feed water starts overflowing. > I'm not familiar with your experience, so this means nothing to me. You only get a stable water/steam mixture in a closed vessel (a teapot). > Why? If it takes say 1 kW to raise the temperature of the flowing water to 100C, and then you supply 1.5 kW (using only and electric heater), then only part of the flowing water will get converted to steam, and you will have to have a mixture of liquid and gas coming out. What other possibility is there? Again, in my experience, with a closed vessel the temperature is just below > 100°C: ~99°C. With a flow system like this, it would be very hard to > manually adjust the flow rate to keep it close to 99°C, to mimic a teapot. > (You could do it with computerized controls.) > Again, your experience is no help here. If the power is just above what's necessary to bring the water to the bp, then you must have a mixture of steam and liquid, and it must be at the bp. Not hard at all. It's hard to get anything else. > > When the cell is first heating up, the feed water overflows. > It's not overflowing. It's simply flowing through a conduit. The temperature rises. You can easily tell when water stops coming through > and it converts entirely to steam. > As soon as it starts boiling, things get very turbulent. Steam is 1700 times the volume of water for the same mass, so it's gonna push things around. It's gonna push all the water ahead of it out, and convert the unboiled water behind it to a fine mist. If 1% of the water (by mass) changes phase, the fluid is 95% gas, with a fine mist entrained in it. This looks like steam, and that's Rossi's ace in the hole. Because uncritical people like you, are so eager to believe in it, that you simply accept it. >>> It is not pressurized, so the temperature will be just over 100°C. > You don't need pressure to increase the temperature of dry steam above > 100C. > > It only goes up to ~101°C in Rossi's test, as you see on the screen. > That's because there is liquid water mixed with it. > > If vessel produces more heat than is needed to boil away the water, the >> vessel itself will get hotter, and radiate into the surroundings. >> > > If the vessel gets hotter, the water will boil earlier in its path > through the device, and the steam will have to get through this hotter > device. > > > A little. That's why you see the numbers on Rossi's screen fluctuate, > occassionally going up to ~102°C. > It's perfectly flat. There is far more fluctuation on the heating and cooling gradients, where the water is liquid with a higher heat capacity. Gas heats up when it passes a hot element. And not just a little. > > That's true but I was referring to the shape of the vessel preventing > unboiled water from leaving. Mostly preventing it. > The fluid is pumped through it. There is nothing preventing water from going through it. You're not making any sense. > > Pumping fluids through boilers is also something people have been doing for > a long time. It is well understood. > Yes, but not by you, evidently.
