The question of continuous versus intermittent draft has also come up in
reconstructions of the Tatara iron smelting process in Japan. The initial
experiments to revise the process (in the late 1960s?) were done with
centrifugal blowers. They were easier on the operators than the traditional
Tatara bellows, which two men stomped on with their feet while hanging onto
ropes from the frame.
Apparently, continuous draft was not as good. Now the reconstructed Tatara
furnace in Shimane Prefecture (supported by Hitachi, I believe) has a pair of
BIG Chinese box bellows run by eccentric cranks and piston rods off a large
(7 horsepower?) electric motor with a speed control. They pump at about the
breathing rate of a person and one can see the flames of the furnace wax and
wane with the pumping. I was fortunate to be invited by Ryu Murakami of the
Nara National Research Institute for Cultural property to visit the Tatara
Furnace last February, and we saw the end of the process -- where the furnace
wall is pulled down and the bloom is revealed.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|