Direct melt furnace question

[julianf]

I've been attempting to clear up the garage...

Too much scrap alloy to bother with a crucible. I'll be there forever.

So, direct melt units -

What stops the solids just sinking down to the bottom of the pool where the heat of the flame is somewhat shielded? I mean, I understand about conduction, but is this how they work?

Or do they have some sort of weir, so they constantly overflow whilst new material is added?


The scrap I have is clean, but thin. If I don't submerge it a bit, and just hit it with a direct flame, I think it will just oxidize away no matter how reducing a flame I use (its 5005 alloy offcuts from work)

I'm aware it's not a prime casting alloy, but it's what I constantly produce. I can't be bothered to weigh it in and swap for something else at present. Maybe I should but I don't think it will happen.


Basically I just want a "box" where I chuck it in and get out some sort of sensible lumps that I can then load to a crucible later or, better still, just pour direct from the "box" into molds.

@8ob -

Did your contraption ever see proper use? How did you find it?


Thank you

 

[jsf55]

The idea is too heat the bricks and not the metal as it oxidises and burns off, with the rotary i used too run you always found the heavier elements at the end of the pour

 

[julianf]

Thank you.

If you're heating the bricks, I don't entirely understand how that doesn't become a batch, rather than continuous process?

Or are you saying to heat the bricks, let that radiate to the solids, and, as they become liquid, they drain off out of the way, as more product is constantly loaded?

I can't see that I'll be rotating anything. This is low level bodgery...



My general concern is that my scrap is mostly between 1.5 and 3mm thick. Without a pool to dunk it into, I fear most of it turning to slag.

I don't have loads and loads but probably over 100kg. Too much for batch melting in my a20 crucible.

 

[Erie Fred]

Get a bigger crucible.

Open hearth furnace in steelmaking put's the fire on the ceiling, to radiate
into the pool below.
Rotary hearth furnace IIRC is much like a cement kiln.