I wanted to see if I could get a solid stream of steam. If not steam, at least a good flow of hot water. Perhaps a insanely large tea maker. My hope was that if I could get steam, I can turn a small turbine. I looked again at the feed horn. I decided to pull off all the stuff that might melt. It was a actually a rather nice looking piece of machined aluminum. If I wasn’t so intent on making this solar thingmabob, I could see it being a very Star Wars candle holder or wine goblet. Since this piece fits perfectly into the holder (as it was sort of designed to be there), it will be used as the mount for my steam chamber. My thought is this, if I can get the water to flow slowly enough, and get a tube hot enough, once the water hits it, it will flash to steam. I bought some 1/4 in coper tubing, some brass fittiings and a 6 inch 1/2 in. diameter metal pipe. I made a coil with the brass tubing that flows in a spiral towards the center of cone on the horn. The idea being that the cool water starts on the outside and warms up as it moves towards the center. Then water is then directed up into the larger metal pipe. The pipe will is in the focal point, so it should be the hottest object on there. Man this is hard to write as nothing has a real name.
The pain here was coiling the tubing without kinking it. All in all I did pretty well, I only ended up with one kink. Once the coil was finished, I fitted it to the horn and attached the pipe. I pushed the coil down into the horn so it followed the contour of the piece. With everything in place it held together remarkably well. I then spray painted the thing with black grill paint. I don’t know if it will get grill hot or not, but if it was how enough to boil water, I figured I should use something a little more robust than standard spray paint.
I took everything over to the dish and screwed it on and got it attached to the hose. I had an interesting problem. I had a hard time getting a gentle steady stream. Even at a low flow it was almost too fast. I figured that I could use 2 taps for the flow adjustment. I wanted to use one for the coarse adjustment, then one for the fine. I really had not thought this through I guess, but once the water built up between the first and second tap, it had the same force through the contraption. There was too much pressure from the house I suppose. They say electronics is like water flowing through a pipe. I suppose I could have just built a water divider and send the rest to um… the ground (via a sprinkler).
Once I got the stream slow enough I aimed the dish towards the sun. My method for testing the tempature was highly scientific. I did not have a thermometer for the metal so I would occasionally touch it (Bio temp sensor). Once it got hotter than I wanted to touch I knew it was on the right track. The water that was coming out was getting warmer and warmer. It too eventually got hotter than I wanted to touch. I let it go for a while. I turned off the water and after a couple of minutes it started to sputter and dribble, then I got steam. I turned the water back on. While there was steam coming off of the water, I never got just a jet of steam. I think that this is mainly due to the pressure of the water. I will do more testing at some point in the future. This is a fun experimenters toy.
In the future I will sand out all the texture that was built into the dish. I think that the combination of the texture and the somewhat sloppy job of putting the aluminum on is softening the focus of the dish. Also, the dish was designed to allow a wide vertical capture area. This means that the focus point is more of an oval than a round point.