02-01-2025, 10:15 PM
I fired the steam generator today. The burner was not working well at all. I shut down after a short period and ordered a second blower fan. Previously, when I had the blower on the burner head to force primary air, the burner worked well at LOW outputs. Increasing the output would cause soot to be produced. I could literally see some black soot blowing out of the exhaust port. I also verified soot accumulation on the steam generator tubing. With the blower moved to the underside to provide only secondary air (bypassing the burner head), what I witnessed was a white haze in the exhaust and strong smell of propane. What I believe is happening is the increased pressure in the combustion chamber due to the new blower position is preventing the burner venturi from providing sufficient primary air. So, propane gas is getting forced UP into the combustion chamber from the burner head with the vast majority not mixing with primary air. So, much of the propane gas is just moving through the unit, getting blown out the exhaust ports, and condensing in air to cause the white haze. Makes sense. So, I need to provide a blower for BOTH primary air (on the burner head as before) AND secondary air (on the underside bypassing the burner head). This seems reasonable. Good news is I don't have to do additional fabrication. I just need to keep the blower on the underside, then add a second blower to the burner head as before (I already have the attachment).
(02-02-25) The fan arrived this evening. I'll fire it up when I get a chance - hopefully this weekend. I will also enlarge the exhaust port as removing the steam generator and re-installing is not difficult.
(02-04-25) Nothing material to share. Just thoughts. So far, I can see a final prototype as not terribly difficult to assemble for small production runs. Yeah, of course this assumes I can get the damned thing to even work! So far so good. But the deck is stacked against me. I have no illusions. I'll just keep plugging away slowly and see what unfolds. That noted, I'm liking the basic design right now.
(02/07/25) Not gonna fire the unit today as it's raining. I removed the steam generator yesterday and added an additional exhaust port. I also placed some ceramic fiber on the base of the combustion chamber, then reinforced the seal for the secondary blower (the one on the underside). Everything appears to be ready for the next test.
(02/08/25) Gonna wait till next week for next test. No time this weekend.
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