metal cylinder that is lined with bricks used to remove impurities from iron. High air pressure is pushed through the bottom to make the process of purification faster.
Tall, tapering, material cylinder, lined with heat-resistant (refractory) bricks, which lowers iron-ore (such as haematite or magnetite) into pig iron. Its title refers to the questionable environment along with other gases (often mixed with oil and tar) required from the bottom through the heated ore to accelerate its decrease.
a furnace for smelting of iron from iron-oxide ores; burning is intensified by a great time of environment
The reason why the frictional resistance would be further increased is the very simple one that the increase in the rate of production implies directly a corresponding increase in the quantity of blast forced through, and hence in the velocity of the rising gases, because the chemical work of the blast furnace needs a certain quantity of blast for each ton of iron made.