Another keg furnace

Discussion in 'Furnaces and their construction' started by joe yard, Feb 16, 2018.

  1. joe yard

    joe yard Silver

    I made it out to the shop a couple of times to work on the burner. The pictures explain as to what I have done. I drilled the exhaust tubing and used 1/8 inch N.P.T. fittings to hang the siphon nozzle. The spacers and lock collars are made from ½ inch nuts. This centered the nozzle nicely while taking up a small amount of space in the tube. The forward lock nut/ collar acts as a burner stop when against the furnace.
    The blower and burner are to be mounted on a slide to allow it to be slid back to just outside the furnace while remaining firmly bolted to the frame. The siphon nozzle will have a 15 psi air brush paint sprayer compressor to supply air. The fuel will be supplied at a positive pressure not over 10 psi.

    Joe
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    Mark's castings likes this.
  2. Jason

    Jason Gold

    That is looking really pro there Joe. Where'd you score that nice blower? My ketchup bottle plenum is some real low class junk. I gotta do something about that one of these days.:oops:
     
  3. joe yard

    joe yard Silver

    It was out of an old civil service transmitter built in the 50s. It runs rather slow but puts out quite a bit of air. It is very quiet.
    The output on the blower is 2.5 inch. I used a standard exhaust adapter to bring it down to 2 inch.
    Joe
     
  4. Jason

    Jason Gold

    Last edited: Sep 11, 2019
  5. joe yard

    joe yard Silver

    Yes, it is a very well built blower. The motor is enclosed with a wrap around type frame that works as a heat sink. The blower housing is made of aluminum with what looks to be a white metal impeller, running at 1600 rpm.
    This is the last part of the furnace to complete. I am very happy with the lift style type furnace.
    This one has taken a very long time to complete. There were many problems but all have worked out. If i was to start over. It would take 1/4 the time. The bore is a bit small at just over 10 inches. I am wondering how it will do on oil.
    The eventual plan is to use natural gas. I have not tried it yet but I am thinking I can inject the gas at the intake of the blower and use the impeller to mix the fuel air while using the light vacuum off the intake to help pull the gas from the line. I don’t know if it will work but it will be an interesting winter experiment.
    Joe
     
  6. PatJ

    PatJ Silver

    Looks good Joe.
    Nice work.
    That is a seriously heavy-duty looking blower.
    .
     
  7. Jason

    Jason Gold

    Go for it Joe. I'd like to see you work the natural gas angle. If you ever have that blower opened up, take photos of it. I bet it wouldn't be that hard to reproduce if we could get some patterns of it made. After all, WE CAST METAL around here. DUH! I'll make mine in BRONZE!:p
     
  8. joe yard

    joe yard Silver

    Jason
    The next time I make it out to the shop I will take some measurements and pictures. It is easily disassembled down too the original aluminum castings.
    It will be interesting to try natural gas. With a bit of luck. That will be a spring, summer endeavor.
    The blower is made very tight so I do not think it would be difficult to prevent gas leaks within the blower. I would have to remake the adapter tube holding the siphon nozzle gas tight.
    Once things are where they will be placed permanently. If I can get the Natural gas burner to the work properly. I will probably just use gas all the time.
    Joe
     
    Jason likes this.
  9. joe yard

    joe yard Silver

    I made it out to the shop today and made a slide to hold the blower and burner. It will allow the burner to be easily removed from the direct chamber heat when not in use .
    The pictures explain it best.
    Time got away and I did not get a chance to measure the blower.

    Joe P1030908.JPG P1030910.JPG P1030911.JPG P1030912.JPG P1030914.JPG
     

    Attached Files:

  10. joe yard

    joe yard Silver

    A few more hours in the shop has the furnace very near finished.
    I have completed the blower slide, installed a shelf for the small compressor to set on and bolted it down. I installed a lid lift lever with detent to hold it open.
    The next part will complete the furnace build with the exception of the igniter. It will consist of plumbing the air and fuel line. Then wiring the switches and plugs to control the pump and compressor.
    The type of ignition is the last part of the puzzle.
    I plan on burning used motor oil at approximately 3 gallons an hour. This is 1 quart every 5 minutes. If I burn diesel I can light the diesel with a spark igniter. After this first 5 minutes. I think the chamber under the pith should be hot enough to sustain a motor oil burn. If not I might place several tungsten tig rods that would heat very quickly in the front of the burner. A propane preheat is also a thought. Just because it is easy for now. When the foundry is completed. I will install a natural gas line that will be used to preheat the furnace and quite probably be the primary fuel during the melt.
    I have been working on and off at cleaning and arranging the back room of the shop with the intent of moving and sorting the stuff from the eternal shed of junk. This shed will then be modified to become the foundry building.
    The building will require structural modification, wiring, lighting and ventilation. I do not think I will be up and running at 100% before spring. I do plan on making a few test runs of the furnace before it is moved into its final resting place in the shed.

    More to come!
    Joe
     

    Attached Files:

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  11. Petee716

    Petee716 Gold Banner Member

    That's some pretty good progress Joe. It's all coming together now. I generally preheat with diesel and compared to motor oil it definitely lights way easier than oil would. I get it hot with diesel and then just switch the fuel lines on the burner once it's hot. But I don't think my application would light diesel reliably with an electric igniter. Maybe it should, and maybe others can because their nozzle is different than mine or they're doing something "right" that I'm not doing, but I need at least some sustained flame to get my diesel going whether it be with a bernzomatic plumbers torch or an oily rag. Only for a second or two, but it needs more than a sustained spark would provide methinks. Even after I've got it started on diesel for a minute or two I can sometimes get a flameout, but by then the chamber is just hot enough that a short burst of an unatomized stream of diesel will auto-ignite and give me the sustained flame I need to restart. I'm running a siphon nozzle so I can just turn my atomization air off for a second to get a fresh squirt of diesel. Your pump may not allow that, I don't know.
    Propane or natural gas are entirely different. I don't really need to tell you that, but propane lights like magic in the furnace compared to diesel and the electric ignitor will probably work just fine. I have sometimes preheated with propane. The propane is not integrated into my oil burner. I tried that before and ended up overheating the oil's siphon nozzle o-ring due to lack of airflow through the nozzle, so I have a separate burner for propane which I just switch out with my oil burner once the furnace is hot. That's very easy for me. Again, your setup is different so you can't just switch the burners out, but you don't have to worry about an o-ring overheating. (You might have other issues like coking, but that's another matter. Just make sure you can easily access your nozzle for removal and servicing).
    The good news is that it doesn't take more than a few minutes to get the bore hot enough to sustain atomized waste oil regardless of what you're preheating with.
    Self igniters for waste oil are common on stuff like commercial made heaters, and they work. I have no idea how they work and at this point I'm not going down that rabbit hole to make one work in my application. I can make diesel work just fine for preheating with my setup, but propane or NG seem like the easier choice for what you have planned.
    Just my 2 cents.

    Pete
     
  12. joe yard

    joe yard Silver

    Pete i typed a 1 page post then lost it. no sleep last night. I will respond later to your post.
    Joe
     
  13. Jason

    Jason Gold

    This board is usually pretty good about saving what ya type, next time it happens, open the same page on your phone and it might still be there just greyed out.
    Unless of course you have one of those fancy flip phones... :p

    Hey Joe... How you making that thing go up and down? Looks like crank power. Do you have to be king kong to yank your crank? I need a dewax chamber that does that on a switch. (project for the new year)
     
  14. joe yard

    joe yard Silver

    I was using Wordperfect to edit my righting prior to posting. I thought I had copied it ready to past so I cleared the document just to find I had not copied the file.
    Years ago I was experimenting with an everything burner. It had a pressure spray nozzle that would light with a spark. It would light diesel and kerosene even if the ambient temperature was below freezing. If I used oil even when thinned with Diesel or kerosene required heating to light. I don't like the idea of preheating the oil but I do like the idea of a propane.
    I have to cut this one short, wife calls.

    Joe
     
  15. joe yard

    joe yard Silver

    Jason
    It is a light duty boat hoist. I wanted to check the amount of force it took to turn the handle before I got back with you.
    It took 5Lb or just under to lift the furnace. New the hoist had a 12" handle. I cut it down to 8" to fit the furnace. The pictures I posted two post back, do not show the boat hoist. The crank that is in one of the pictures is the lid lift lever. It can only be used when the body is in the full down position. The lever has a detent in the handle that locks in the up or down position.
    I was at the shop most of today and worked mostly on the fuel system.
    There is not a lot of progress to show. I have to pickup some plumbing fittings before I can put much more together. I have a 12' X ½" hydraulic hose I will be using to deliver fuel to the furnace. The fuel system will be in the building with the furnace. They will be separated from each other by a heat shield partition wall.
    I am using a siphon nozzle.
    I will put an electric fuel shut off valve on the nozzle line near the burner.
    There is quite a bit of fuel up stream after the pump. It goes through the filter, flow control valve and 12' line before it gets to the burner. With it being a siphon nozzle I am concerned it might pull from this reservoir if the compressor is running.
    I will be putting a ball valve at the fuel tank as a mechanical shut off.
    I am wiring it so any time the blower is running. The compressor is running. The compressor can be ran with the blower off independent of the blower.
    The compressor is a low pressure, diaphragm type. Made for paint sprayers.
    Built to run continuously clean 20 - 25 Psi air forever. I want to keep the nozzle and the fuel in it cool when not in the furnace. During cool down I will run air through the nozzle to clear and cool it.
    When the burner is slid backed out or the furnace. A metal plate drops down and acts as a heat shield between the furnace and the burner.
    With some luck. I hope not to be unclogging a nozzle very often.
    I am going to try very hard to maintain the flammable motor oil based mix. It will be reasonably filtered and dry.
    The black circle is the lid lift leaver. The red circle is the boat hoist that lifts the furnace cylinder and lid together.

    Joe

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