Simple Brick Furnace

Discussion in 'Furnaces and their construction' started by oldironfarmer, Mar 30, 2018.

  1. oldironfarmer

    oldironfarmer Silver Banner Member

    Made a level gauge for my pressurized oil storage tank. Nothing fancy but I finally realized I should have a clip on one so I could move it to the oil level, clip it on, and then measure the number of quarts used directly. Clip is not the final solution.

    Jason and joe yard like this.
  2. Jason

    Jason Gold Banner Member

    The simple solutions are the best.
  3. oldironfarmer

    oldironfarmer Silver Banner Member

    Is that a gauge/handle?
  4. Peedee

    Peedee Silver

    In my extensive experience of getting product approval I don't think the chaps at UL are going to like what you did there Jason ;)

    Your sight tube is typical of what we use on fuel oil tanks here except the top is open to the air and a plunge valve on the bottom is used to stabilise the level (In case the tube gets knocked and 30,000 litres of fuel oil departs south bound!)
  5. Jason

    Jason Gold Banner Member

    I never noticed the UL on that thing. Who would think UL has anything to do with refrigerant? Last time I looked, that r22 can was about 700bucks. 2020 is coming guys, then say goodbye to this stuff! I quit buying the stuff last year. Too expensive to have sitting around waiting on someone to need it.
  6. oldironfarmer

    oldironfarmer Silver Banner Member

    UL approved my gauge.

    But Uncle Leon approves of anything that doesn't keep him from his beer.
  7. oldironfarmer

    oldironfarmer Silver Banner Member

    Inspected the 2,600F wall brick after two more iron pours. Satanite has turned to glass, and brick is shrinking (melting). But it looks like it still has a few more heats in it.



    I really need a round plinth. but my aluminum oxide floor protection is holding up well.
  8. OMM

    OMM Silver Banner Member

    To what temperature is Satanite good to? I’ve been holding out pretty hard on buying any refractory until I see what I get. I was told it’s 3200 F brick. And I’m holding my breath on its condition.

    Andy, I’m thinking along the same Avenue you have went but building smaller than a 55 gallon drum. I am also thinking just using Rockwool on the backside of the brick. Thoughts?
  9. Melterskelter

    Melterskelter Silver

    Could you somehow draw and arrow or two on your pics to show where the satanite has glassified? I am surprised it has done so, as I have not yet seen it glassify in my furnace despite being only on 2600 wool. Maybe your fire is hotter?

  10. OMM

    OMM Silver Banner Member

    Jason, I do like your set up. I do have a scrap small duel tank 5 gallon air compressor that I think would suit my needs for tanks. I think 2 1/2 gallons per fuel might suit my needs initially.

    Andy, with your larger furnace, how much fuel would you go through per melt? Or per session?
  11. oldironfarmer

    oldironfarmer Silver Banner Member

    High Temperature Tools & Refractory state Satanite is good to 3,200F.

    Mineral wool should be good to 1,200Fso as long as you don't have gas leakage through gaps in the brick it should hold up fine.

    I really don't know how much fuel I'm using. It is immaterial to me, so long as I can get enough air in to burn it all (flames not roaring out the flue) and I'm currently air limited. With my leaf blower on low I have my damper wide open and burn around 3 quarts in 20 minutes to melt 5 lbs of aluminum, that's my stainless steel crucible full, 4" IDx6" deep. I made a level gauge so I could evaluate fuel usage but always, and I mean always forget to check it after I've poured.

    It think bigger is better because more good insulation keeps the exterior cooler. When you start with a small exterior you are limited on interior space. For burning oil I also like a large interior space to give whatever oil flow I'm burning more time to stay in the firebox.
  12. oldironfarmer

    oldironfarmer Silver Banner Member

    I'm not too good with computers so forgive me.


    Initial flame impingement is upper right in the picture, burner is off the picture top right. This brick is getting the first bounce, and the flame impingement area does not have full combustion and gets deposits of contaminants. So this may be the hottest area.
    Melterskelter likes this.
  13. oldironfarmer

    oldironfarmer Silver Banner Member

    Still haven't replaced any brick, although several of the wall brick have horizontal cracks through, so the top part is just resting on the bottom.

    Hit a small milestone this morning. 400 melts now on the new furnace. Maybe it's not new?

    Tobho Mott likes this.
  14. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I think 400 melts is a major milestone for any furnace. How many heat cycles would you estimate? With IFB, I think you will find heat damage to be relatively superficial with respect to insulating properties but more serious to mechanical properties, meaning they will still serve their purpose well if you leave them in place but if you handle them, they may fall apart. Contact with metal and fluxes on the other hand cause more extensive deterioration. Still, very small job to replace them for the next 400 melts.

  15. Melterskelter

    Melterskelter Silver

    I do think Kelly is right to be thinking of heat cycles as a major determinant of furnace life. I have recently changed practices due to (belated) recognition of the degrading effects of heat cycling.

    Time and weather considerations have nudged me to simply turn off my furnace and let it stand open in hopes of cooling off my chimney to a safe handling temperature so it can be stowed until the next melt. But at times I have heard sharp pings while I work in the vicinity of the cooling furnace and I know that cold air is tying the various refractory surfaces in knots.
    The pings have to mean a good sized crack in something and thousands of silent micro cracks have to be ongoing.

    So, I added safe-handling handles to my chimney so that I can put on welding gloves and pull off the 500-degree chimney and put a disc of wool over the vent and plug the tuyere with wool. That’s what I did last time. No pings. And the cooling rate must be many times slower. Now, if there were just a practical way to ramp the temperature up...

    Anyway, I feel like I have been neglecting the importance of slowing the cool-down rate of the furnace. Confession over, I feel better. ;-)

  16. oldironfarmer

    oldironfarmer Silver Banner Member

    I imagine about 1/4 on the melts were in a hot furnace rather than cold start, putting it at around 300 heat cycles.

    I do try to close the lid to let the furnace wait or cool down.

    Slow warmup is very practical if you choose to spend the time to warm up slowly.
  17. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Yah, there's this tendency for people to gage their foundry furnace and burner performance around shortest melt cycles.......without a doubt, it's rapid and extreme temp cycles that are the hardest on a foundry furnace......and often times, the fuel source is (free) WMO or WVO. To me, the difference between 20 & 30 minute melt time is meaningless and I'd take the 400 melts over the 10 minute difference every time.....but to each his own. If you can simultaneously achieve both, I say all the power to you.

    To me it's sort of like bench racing your dyno don't race dynos and if it doesn't get you around the track any faster, what good is it? Sure, you can melt something faster, but how are your castings doing?

  18. Tobho Mott

    Tobho Mott Silver Banner Member

    Wow, impressive notes, good idea. I try to slow cool my furnace too. I stuff the vent hole and tuyere of the new one with scraps of fiber blanket when a session ends; once I peeked inside a few hours later and my plinth was still glowing. But I must admit, I have never considered trying for a slow heat-up. Usually I just block the vent of the big furnace with a couple of ordinary old red clay bricks and leave it at that, but the new furnace is much more fragile.


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