On Tue, Jul 5, 2011 at 11:26 PM, Harry Veeder <hlvee...@yahoo.com> wrote:
> Assuming the boiling is always happening at the same pressure, you can > extend the horizontal line B-C to the temperature axis and treat that as the > temperature of boiling. Wet steam is present only AT the temperature of > boiling. As long as the temperature of the vapour is just above the boiling > temperature then you can be sure it is dry steam, even if it is only a tenth > of degree above the boiling temperature. > > Perhaps, but we don't know that it is a tenth of a degree above the boiling temperature. If it were, then when it reaches point C, you should see an increase in the temperature by 0.1C, but there is no indication of such an increase. And then the ecat would be operating on the steep gradient between points C and D. It would have to be stable to a fraction of a per cent for the temperature to remain so perfectly constant. That seems impossible. The perfectly regulated temperature is much better evidence that the steam is at the boiling point than the absolute measurements of the temperature and pressure are that the steam is 0.1C above the boiling.
