Hot Blast
a stream of air forced through a furnace and heated to 500° or 600°. The combustible gases from the stack are generally used to heat the For this purpose a kind of oven is built near the top of the stack,sur mounted by a kind of chimney which draws off a portion of the inflamed gas.
In this oven is a series of pipes through which the air is forced before it enters the stack. The hot blast effects a saving of heat, and accomplishes the reduction of the most refractory ores in less time and with a less expenditure of fuel than the cold blast.