In the given figure of a rotary melting furnace, what does the question mark depict?
(a) Steel shell
(b) Exhaust box
(c) Refractory lining
(d) Molten metal
I had been asked this question during an online interview.
I'm obligated to ask this question of Rotory Melting Furnace topic in chapter Metal Furnace and Practice of Casting-Forming-Welding II