When I heard about these tests, I suggest they sparge the steam into a bucked. (You would not need a 55 gallon drum at this power level.) It turns out my message arrived after the tests were complete. That's a shame.
Here is the procedure I suggested: 1. Weigh the container. 2. Add water, weigh it again. 3. Measure temperature of the water in the container. 4. When full steam production is reached, insert the end of the hose to bottom of the container. (This should be a short hose.) 5. Hold it for a short, measured time, say 5 or 10 minutes. (This is important -- a long test does not work.) 6. Remove hose. Measure the temperature again, and weigh everything again. 7. The increase in weight and temperature gives the full enthalpy and the extent to which the steam was "wet." Here is what Mats Lewan wrote to me today: "The mass [of water in the bucket] was about 5 kg, including some vapor that was condensed in the bucket (the hose was kept under water). Impossible of course to say exactly how much was condensed in the tube and how much in the bucket. We did not measure the temperature. I cannot see that this could give much information as the bucket in no way is an isolated system. We have a completely uncontrolled loss of heat from the bucket." He also mentioned that the hose is long, as you see in the video. I wrote back: "You did a pretty good job! If you have a chance to do it again, the trick is to measure the mass and temperature of the water in bucket *over a short period of time*, say 5 or 10 minutes, close to the start of the test. The reasons is -- as you say -- there is uncontrolled heat loss from the bucket. So, you start when the temperature difference between the bucket and the room air is small. And you continue for only a short while, so that not much heat is lost. Stir the bucket vigorously to be sure the water temperature is uniform. The heat lost in the hose is a problem, so it is better to do this test with a short hose. It is not the most accurate method, but it is a good back up, or secondary confirmation, of your primary method." People here who are complaining about wet versus dry steam should note that the heat required to heat the water to boiling exceeds input power by a small margin, and you can see for yourself there was steam coming out of the end of the long hose. I realize there are claims that wet steam can have only 1/20th as much enthalpy as dry steam, but even at that ratio there is still significant heat from this test. In any case, the engineering textbooks disagree with that hypothesis. I am sure the enthalpy of that steam was reasonably close to the amount estimated by Lewan. If he had used the RH meter used previously, the skeptics would not have believed him any case, even though various experts has said that meter is fine for this purpose. The sparge test would have underestimated the enthalpy by a large fraction, with such a long hose. Anyway, there have been plenty of other tests previously with both flowing water and steam, and there will plenty more tests in the future. - Jed
