Abstract: A mixing chamber for mixing hot blast exiting from a hot blast stove with cold blast from a supply thereof to provide a uniform blast mixture adapted to be introduced into a blast furnace. The chamber comprises an open ended tubular member defining openings at opposite ends thereof, one of these openings being an entry into the tubular member and the other being an exit therefrom. The entry is adapted to have introduced therethrough hot blast exiting from a hot blast stove while the exit is adapted to communicate with the blast furnace. The tubular member is provided with a pair of diametrically opposed passageways therethrough, each of which is oriented tangentially with respect to the inner surface of the tubular member.