The advanced furnace

Hastelloy wants 950 to 1,000 K and 25,000 to 30,000 kPa – a window of only 50 Kelvin. With simple pumps and hysteresis the furnace easily swings beyond it. The advanced furnace brings its own inlets and outlets that the chip can meter finely.

What sets it apart#

StructureAdvancedFurnace (advanced furnace) needs power (100 W, plus up to 100 W per valve, the further it is open) and has On. On top of that two valves of its own:

You know everything else from the simple furnace: Temperature, Pressure, RecipeHash, Open, Activate, Combustion – and Mode as a mere display. And only here do the superalloys succeed. They are dearer too: a superalloy ingot needs 4 units of melt, every other ingot only 1.

Using Setting: two P controllers#

Instead of on and off, the chip sets the valves proportionally to the deviation – as with the P controller:

sub outflow press P_SET
mul outflow outflow KP
clamp outflow outflow 0 LITRE_MAX

If the pressure is 2,500 kPa above the target, the outlet opens to 2,500 · 0.02 = 50 litres per tick. If it is below, the value turns negative and clamp makes 0 of it. The same holds the other way round for the temperature: the colder, the more fuel.

clamp matters here: the valves only know 0 to 100. A P controller without a limit would write nonsense at a large deviation.

Removing the exhaust#

The outlet pushes furnace gas into the output line. That line has to be able to take it – if it leads into a full tank, pressure builds up in the furnace despite the open outlet. Plan the exhaust line with a tank or a vent to the outside, and keep an eye on its pressure.

For the window a light reports whether all four limits are kept. A second light reports when the furnace can no longer be reached.

sge window temp T_MIN
sle tmp temp T_MAX
and window window tmp