Cupola furnace
| # | Colour | Name | Matches |
|---|---|---|---|
| 1 | any Refractory bricks | game:refractorybricks-good-tier* | |
| 2 | Cupola Furnace Core | iiex:furnace-cupolacore-*-n | |
| 3 | Iron Tap | iiex:furnace-irontap-e | |
| 4 | Slag Tap | iiex:furnace-slagtap-w | |
| 5 | Tuyere | iiex:furnace-tuyere-* | |
| 6 | Tall Hopper | iiex:hopper-tall-w | |
| 7 | Reserved space (kept clear) | exlib:structurefiller | |
| 8 | Empty (air, or a pile of coal, or a charge Pile) | *:@(air|coalpile|furnace-chargepile) | |
| 9 | Empty (air, or a pile of coal, or a charge Pile, or a solidified Metal) | *:@(air|coalpile|furnace-chargepile|hearthmetal-.*) | |
| 10 | Empty (air) | game:air |
Materials
| Block | Cells |
|---|---|
| any Refractory bricks | 52 |
| Cupola Furnace Core | 1 |
| Iron Tap | 1 |
| Slag Tap | 1 |
| Tuyere | 1 |
| Tall Hopper | 1 |
Facings and connectors
- Cupola Furnace Core turns with the structure; segment 4 of its code names the face.
- Iron Tap turns with the structure; segment 3 of its code names the face.
- Slag Tap turns with the structure; segment 3 of its code names the face.
- Tall Hopper turns with the structure; segment 3 of its code names the face.
- Connectors on the north face: cell 0,2,-1.
What it does
The cupola remelts pig and scrap into cast iron. It is the same machine as the Cold blast furnace running different data: the raceway, the columns, the melt, the taps and the extinguish rules are all inherited unchanged. What differs is what it eats and what it makes.
It takes Pig Iron, Pig Iron Chunk, Pig Iron Shot and iron or steel scrap directly, layered with fuel, with no prepared burden of any kind, and it melts them at 1200 C, which is well inside what a plain charge reaches on cold blast. Remelting scrap is an iron-age job; reducing ore is not.
Building it
- Place the core first. It is the hearth grate at the bottom centre, and the build hangs off it.
- Ctrl plus shift plus right-click it for the build outline and the shopping list.
- Lay the walls course by course, leaving the shaft hollow.
- Set the single tuyere two courses above the base.
- Set the iron tap and the slag tap at opposite ends of the hearth course, one course above the base.
- Set the tall hopper on the shaft's side, four courses up.
- Keep laying until the outline reports complete.
It is a smaller build than the blast furnace and it is the same shape of build: same anchor, same outline gesture, same tap and tuyere rules, same refractory in any tier. The core's side variant fixes the facing and the layout turns with it.
The charge
A cupola pile counts metal units rather than items. One block of pile takes 3000 units of metal on top of its fuel, and a whole pig is 375 units, a chunk 25 and a bit 5, so one block of pile is 8 pigs, 120 chunks or 600 bits against about half its height in fuel.
Charge in alternating rounds through the hopper, fuel then metal, exactly as the blast furnace is charged.
A cupola is slower than a blast furnace and the pacing is geometry rather than a constant: one tuyere burns less carbon, and the same carbon rate is stretched over a far denser pile. Two cupolas roughly keep pace with one blast furnace, drifting with how hard each is blown.
The first run
- Put a canal start under each tap's spout.
- Charge the shaft in rounds until it is full.
- Start the blower. The cupola draws 12 L/s through its single tuyere at the reference fuel fraction, and asks the same pressure as the blast furnace.
- Break a tap's plug out with an empty hand, then hold a torch to the open tap.
- Cast iron runs out of the lower notch and slag out of the upper one.
What goes wrong
It says Firing and renders nothing. Ore burden was charged into it. Burden in a cupola burns, counts toward the fire and converts to nothing, and pins the furnace in the Firing state. Dig it out and charge metal.
The pile looks like fuel all the way up. Pig and scrap draw as fuel in the shaft wall until their own art lands. The block info is the accurate read.
The pool filled and the furnace stalled. The cupola has one pool cell against the blast furnace's three, so 640 units fills it. Tap more often.
It goes out faster than expected. A shaft burns until its carbon is gone and there is no fuel clock. A pile that is mostly metal and thin on fuel runs a short campaign.