The solar furnace

And other alternative energy stuff

 What is it?:

 A C/Ku-band (aka "big dish") satellite receiver dish converted to collect solar energy and heat water. The parabolic collector that reflected radio waves to a single concentrated point now reflects sunlight to a "boiler" at this point. To follow the sun's arc the dish is controlled by two linear actuators to give it up/down-east/west movement. The actuators are controlled by the tracking system that also monitors the system temperature and parks the dish when the maximum temperature of 200Deg F is reached.

The story:

One night I was searching for ways to increase my Bluetooth range at the house when I stumbled upon this site: "The Light Sharpener"  It starts to get pretty interesting at about page 13.

So it was time to blow the moss off the old ten footer in my back yard and get to making hot stuff.

De-funked. Lovely isn't it?

This thing has been pressure washed so many times the screen mesh that was embedded is now exposed. I was originally concerned about any texture coming through but when I got the 5mil material in my hands it was obvious that wouldn't be a problem.

Materials from McMaster Carr. The 3M Blue72 is a contact adhesive that only needs to be applied to one of the surfaces being bonded. The sheeting is a 5mil metallized polyester [PET] film. The Speedhide primer didn't get used.

My neighbor Jim lent me some tools and a little paper hanging know how. I cut 9" strips and used 8" reference lines off the center vertical seam.

The two tubes you see glued into the edge will be for the tracking optics. I decided to have one for each axis so one wont affect the other when doing fine tweaking. (and failing, learning, etc.)

The first few pieces go on fast. Gotta watch where you stand, YEEEEOW! Lots of tedious trimming ahead. I ran out of adhesive a few more rows up since I didn't see that little adjustment on the can for flow, oops.

Using the old feed horn mount as a jig to build the collector.


Tomorrow I'll try to score some Blue72 locally. Need to start thinking about plumbing too.

The Blue72 had to be ordered as I suspected. But it's McMaster Carr wich means it will probably be on my doorstep by the time I wake up in the morning. (yes they are so fast it's freakin' scary)

Content removed: I scrapped my original tracker design for the system from AnalogGuy. Didn't want anybody wasting time on junk. I will reconfigure it later as a "shadow hoop" style for a PV setup.

I went ahead and dialed it in for a quick test with some cardboard. WOW! I knew it would work but WWOOWW!! It's obvious I need to keep a close eye on things during the debugging stages, probably even a cover.

Here's a little quick test video:

Finishing up the collector. I figured overkill wouldn't hurt in this area so all connections are welded. The thinwall tube inside the collector is just a short section to help promote crossflow and purge air, the rest of the system is black pipe.

And tomorrow I hook up the garden hose for some quick testing.

You can see the clouds coming in the background, I literally had minutes to try it with the hose. I had about a 1/4" stream coming out at bathwater temp. It was obvious the collector needed to be lower.




Here's the revised collector and if the rain keeps up it may get revised again.

So do you believe in Deja-vu? This one was a wow for me. Back when I first quit drinking 21+ years ago I had lots of strange dreams. Most were written off as me working out issues. But, I specifically remember dreaming about me working on this thing. And then waking up thinking "WTF was that thing I was working on and why did I have one?" . Then as I was spraying paint on it last night it hit me "THAT'S IT!" my freakin' heart jumped. That little chunk of a dream stuck with me because I like to think I can identify more mechanical/industrial widgets than most people and that thing left me clueless at the time. Well no wonder, I hadn't designed it yet!

Tomorrow we're supposed to get more sun. Hopefully I can at least get some inlet/outlet temps with vid to show the stream. Then I need to clear a space in the shed for the tank and get some solid numbers with a circulating system.