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Thread: Delavan Siphon nozzle issue not working

  1. #41
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    That is some serious brightwork there.

  2. #42
    Thanks in part to the tuning tips I received here, I've pretty much got this sorted.

    Did most of the refractory cure with propane, since it's so much easier to control. Switched over to 50/50 waste oil/Diesel for the last few hours. I'm amazed at how powerful this thing is!

    Thanks again for all the tips!
    https://youtu.be/w8uD00BYLcI

  3. #43
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    Looks like it is running well.

    Is the end of the burner tube red hot, or is that an optical illusion?

  4. #44
    Quote Originally Posted by cjcaster View Post
    Is the end of the burner tube red hot, or is that an optical illusion?
    Somewhere in between.

    When I finished the cure and pulled out the burner, it had a slight glow that was only visible because it was night time. Probably couldn't have seen the glow even in ordinary artificial room light. Not really "red hot", but certainly very warm.

  5. #45
    PS: A few things I've learned already that I would do differently:

    - Running the air and propane lines through the side of the pipe was a needless fiddle. If I ever make another one of these, I'll just run them down the pipe and out the end, fabricating a "plug" with three holes from there.

    - I am certainly going to add a needle valve for controlling the oil flow. The ball valve isn't precise enough to get the flow dialed in exactly right.

    - My poor old compressor was sounding pretty pained by the time this was over. Can't believe it made it through a total of about 11 hours of firing. I also think a bigger one will help. Mine is so small, there is very little air storage. I didn't think to time it, but it felt like it was running about half the time I was doing this. That means I have to run very high pressure, and you could really see it in the burner: The pressure would bleed down and the flame would go down with it, then the compressor would kick in and the flame would come back. Plus, running such high pressure made the control of the air supply needle valve a very touchy business. My theory is that a bigger compressor with a bigger tank will let me run lower pressure and make the adjustment of the air supply needle valve a bit less finicky. Kind of an "HVLP" thing.

    - I did the first half or so of the cure on Propane. Glad I did, too. Controlling the burner on Propane is trivial.

    - Controlling this thing on my 50/50 liquid fuel mix is another thing completely. I was trying to do a gradual heat up, and keeping the burner under control was my only issue. That thing runs like crazy. I have no idea how hot it can get. I don't feel like I got anywhere near the limit. Even when I was doing my final run at 1800F, I had both the air and oil throttled way back.

    - My cheapo Target hair dryer worked well enough. It has a button I taped off that turns off the heating element, so it's just running on the fan. After a number of hours, I started thinking I was pushing it too hard, so I switched over to my ShopVac. I think in ordinary use, where I'm only running this thing for maybe an hour or two max, the hair dryer will be fine.

    - All told, I used the better part of a tank of Propane, and about 2 (might be closer to 2.5) gallons of oil/Diesel mix on this.

    This morning, it was still just a little warm. Looks like it came out ok. There is one small surface crack (too small to photograph) down by the tuyere and another one in the lid. Other than that, I think I'm happy with the way it looks.

    Foundry.jpg

    Here is a video showing the burner in action. This was right near the end of the cure.

    https://youtu.be/g01hTKRbr-M

  6. #46
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    Its a little hard to tell, but I am assuming that the tip of the siphon nozzle and the spin vane are near the end of the burner tube?

    I see from your video why the burner tube is getting hot; it is protruding into the furnace.
    You may have to pull the burner tube back to it does not protrude into the furnace at all, but is completely contained in the tuyere, since I think that sort of heat on the end of the burner tube may cause problems (not positive, but I suspect such).

    I use a pressure regulator for the compressed air, and no needle valve, only a ball valve. When running, the ball valve is 100% open, and the compressed air pressure is controlled with the regulator.
    Regulator similar to this one:
    http://www.homedepot.com/p/Husky-3-8...5HOM/205332108

    I think people try to make these from hardware store parts only, in a bolt together fashion, but the side entry and all those elbows really complicates something that can be built in a much simpler fashion with a fraction of the part count.

    I prefer the pressure regulator with gauge be remote from the burner and not bolted to it, since anything hanging on the side of the burner tends to get damaged over time.

    I can tell you how hot an oil burner will get; they will melt the end right off your temperature probe, and melt any refractory that is not rated for almost 3,000 F.
    When I am melting iron, I can stick a piece of rebar into the melt to stir it, and after about 20 seconds, the end of the steel rebar is gone.

    If you don't have a good graphite crucible, it too will fold up like a waffle (if you try to melt iron).
    I have seen photos of this happening.

    Good luck.

    Edit:
    Also, I generally seal the burner tube to the furnace to prevent any hot gasses blowing out the tuyere, which will definitely melt a pressure gauge.

  7. #47
    Quote Originally Posted by cjcaster View Post
    Also, I generally seal the burner tube to the furnace to prevent any hot gasses blowing out the tuyere, which will definitely melt a pressure gauge.
    Again, thank's for all your advice. Much appreciated.

    I was wondering about the placement of the burner in the foundry:

    BurnerTubePosition.jpg

    I was concerned that I didn't want the oil/flame hitting on the inside of the tuyere, but maybe I should back it out a bit?

    I've got some kaowool coming that I will wrap around the burner next time to try to seal that up a bit. My graphite crucible is in hand, but I still need to figure out something for tongs. I would have thought they would be readily available, but if they are, I haven't found them.

    My objective here is strictly aluminum and brass melting, so hopefully I never have to get to the seriously high temps for ferrous work. (I used 3000 degree refractory.)

  8. #48
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    I would position the burner tube like your diagram on the right, but pull it back about another 1/8" to 1/4".

    Is your nozzle tip and spin vane positioned in the burner tube like the photo below? (the spin van is optional, some use it, some don't; I stopped using one).

    Two photos show a later setup that I currently use, which is no spin vane, but with three fins to center the nozzle in the tube, and allow the nozzle and associated parts to be retracted from the tube.

    You can try the burner with and without the spin vane, and use whichever works best.
    Attached Images Attached Images

  9. #49
    This is my spinvane setup.

    spinvane.jpg

    I'm not sure it's good for much other than centering the nozzle, but it does do that, so I guess that's good enough.

    Next burn I'll try puling the nozzle out a bit and see what we get.

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