Buried furnace idea

Discussion in 'Furnaces and their construction' started by Jimmymmm, Aug 6, 2022.

  1. Jimmymmm

    Jimmymmm Copper

    My wife has finally accepted this as my hobby, and has offered a dedicated place in the backyard for my furnace. As such, I'm trying to play nice and find a way to isolate my mess and keep her happy with a nice backyard. I've been contemplating a new waste oil furnace... and now wondering about burying it up to the lid. This section of the yard is desert landscape with a rocky, sandy topping, and I could easily hide the outcropping lid without any issue.

    My plan is to use a steel shell and Mizzou inner like my current furnace. I typically sandwich kaowool in between for insulation, but wondering if kaowool would be necessary as the surrounding earth may act as an efficient insulator.

    I'm trying to work out the method for air and siphon nozzles since it's underground, but I have a couple of ideas. I would like to bump from 1 to 2 nozzles for this furnace, which makes it a little more difficult, but I'm working on that as well.

    Anyway, I have no idea how effective is ridiculous a buried furnace may be, so I'm looking for feedback on whether this is something worth pursuing. Give it to me straight!
     
  2. Tops

    Tops Silver Banner Member

    I am picturing some sort of metal/mechanical Saguaro cactus where by turning an arm Maxwell Smart style the furnace rises from the ground or lifts the lid... :)

    [​IMG]
     
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  3. It's not a furnace!....it's a high speed Tandoori oven!!!.

    tandoori.jpg
     
    Last edited: Aug 6, 2022
    Jimmymmm and Tops like this.
  4. Tops

    Tops Silver Banner Member

    Mmmmm high-speed Tandori!

    Jimmymmm, how is the weather and soil conditions in your area? My guess is that you will need some separation between surrounding earth and the furnace to be able to feed it air and fuel and care for it.

    I really enjoy these videos of lower-tech foundry work from around the world. I cringe at the lack of safety gear but marvel at how they get the job done.

    [​IMG]
    LOGIC CREATIONS

    49.3K subscribers


    In this video we are presenting an amazing process of rebuilding expired stainless steel casting furnace. Many people requested us to shoot the amazing process of making dead metal melting furnace

     
  5. HT1

    HT1 Gold Banner Member

    Please dont bury your furnace outdoors , there are so many bad things you cant control , and if you have a spill small or big cleaning it out will be a nightmare , you would be so much better served to just hide the thing, if you don't want to put it on wheels and hide it that way consider a fake rock or stump, and no im not advocating buying one, if your in a dry climate, chicken wire and paper Mache, with a good coat of sealer ...;) satanite would look natural , you could have a lovely large rock in your landscape

    https://www.amazon.com/Dekorra-Faux..._1_9?keywords=Faux+Rock&qid=1659875409&sr=8-9


    V/r HT1

    P.S. I cant imagine the back pain involved in lifting a crucible out of a furnace below ground
     
  6. Mantrid

    Mantrid Silver

    put up a timber fence in front of the area, or a wall of high shrub type plants
     
  7. Jimmymmm

    Jimmymmm Copper

    Putting up a wall is the first option, but I want to ensure I look at all my options before going forward.

    The ground here is a fine layer of sand followed by many feet of rock, mostly sandstone. I have very limited garage space so I have been jackhammering some trenches to bury/cover some of my supplies, tools, storage bins containing the metals prepared for future use, as well as other unnamed stuff. It was this that got me thinking I could bury my furnace.

    [​IMG]
    https://imgur.com/a/y5QALR7

    I figured I could fashion an a-frame to winch the furnace out of the ground as necessary. And add some length to my tongs and other tools so I wouldn't have to bend over. And while I love the disguised access via a seguaro, that could be the most challenging part of the project. Well, aside from the burners and airflow.

    Anyway, unless I can come with a good way to implement the seguaro disguise, it probably won't happen. But it keeps the brain sharp to keep thinking about new ideas and ways of doing things.
     
    Last edited: Aug 7, 2022
  8. Tobho Mott

    Tobho Mott Gold Banner Member

    The furnace in Bill Jurgenson's foundry was installed in a pit, with the lid at ground level. Not outdoors though...



    Jeff
     
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  9. HT1

    HT1 Gold Banner Member

    note the steel grate around the furnace, that is a pit furnace below ground level. but it's not in contact with the dirt, so it can be removed and worked on if necessary


    V/r HT1
     
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  10. Tobho Mott

    Tobho Mott Gold Banner Member

    Pictures of the available space around the big furnace in its pit are here:

    http://forums.thehomefoundry.org/index.php?threads/new-member.890/#post-20505

    In a few more years I should be able to expand and upgrade my foundry shed with more room to work and add a similar pit to house Bill's furnace and get it running again. Until then I don't have the space to run it, or for the gantry crane to move big crucibles around. Note, you wouldn't need such a big hole or nearly so many miles of burner plumbing for a sensible hobby sized furnace.

    Jeff
     
  11. Jimmymmm

    Jimmymmm Copper


    Good points. An open space around the furnace makes sense. This would make it much easier for maintenance, as well as manage the air and oil supply lines to the burner. In this case I would still need to insulate between the hotface and shell, but that would let me extract the furnace and run it above ground as well. I just need to remember to weld some loops so I can lift the furnace when necessary.
     
  12. Melterskelter

    Melterskelter Gold Banner Member

    Just thinking through the use of such a setup. I would think you would want to have the combustion air and fuel flow adjustabel from ground level not down in the pit. Given propane's proensity to pool, If you intend to run propane as an initial heating gas, I would want to have provision for excellent air purging of the pit. In fact, I would not use propane for a starter. Running diesel for five minutes and then switching to WO would be much safer and would be so easy. I light my diesel reliably with just a paper towel half soaked in diesel, lit and dropped into the furnace followed by low combustion air flow and turning on the fuel at low level. I definitely would not want to be in that pit if the propane went foomp.

    You likely already had that all figured. But, just saying...

    Denis
     
    Last edited: Aug 8, 2022
  13. Jimmymmm

    Jimmymmm Copper

    I haven't worked out the fuel and air adjustments yet, but you're spot on, they certainly need to be above ground level. I'll work on the overall furnace design, and I expect to work it out then.

    I read about your method awhile back to start the furnace with diesel, and I've been using it successfully ever since. Thanks for that, it made things much easier. I still use propane for my forge, but agree that I don't want to use propane for an underground furnace. I've also had success using pre-heated oil through the nozzle, I may have to revisit that again as well.
     

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