I’ve done some blacksmithing as a hobby. The two most common ways of heating the metal are a gas furnace and a coal forge. The forge normally has some sort of forced air coming from the bottom to feed the fire. The coal starts burning real smoky like, but then turns to coke and burns hotter the more air you force through it. Typically you pile some coal around the sides of the fire so it converts to coke then you scoop it into the fire as needed. Also it produces a waste product called clinker that builds up at the bottom of the fire at the tuyere (the nozzle or grate the air is forced through). It’s kind of like stone or metal and it needs to be cleaned out to keep the fire going.
I’ve done some blacksmithing as a hobby. The two most common ways of heating the metal are a gas furnace and a coal forge. The forge normally has some sort of forced air coming from the bottom to feed the fire. The coal starts burning real smoky like, but then turns to coke and burns hotter the more air you force through it. Typically you pile some coal around the sides of the fire so it converts to coke then you scoop it into the fire as needed. Also it produces a waste product called clinker that builds up at the bottom of the fire at the tuyere (the nozzle or grate the air is forced through). It’s kind of like stone or metal and it needs to be cleaned out to keep the fire going.
Fun fact for those who don’t know. You can forge metal with a wood fire if you have forced air.
There are also ways to build a clay oven so that it has a natural updraft, giving it that forced air. It’s actually how people used to fire pottery.
Other than that, you can also use charcoal, which burns hotter with forced air.
Also, a hairdryer puts out enough air to forge with *unless you’re running a ribbon burner set-up. But if you are, you likely know that already.
-A fellow hobbyist blacksmith
*Edit to add a word.
Most smithing was done for centuries with charcoal.