DESIGN OF OPEN-HEARTH FURNACES
this point. The reactions here are complex, as certain hydro-
carbons dissociate in the checkers, as well as C02. A further
increment of moisture occurs in certain elements of the charge,
and an open-hearth furnace is not particularly efficient as a dryer.
At the same time, moisture is carried in by the air supply. All of
this water leaves the regenerator for the stack as highly super-
, of F.arnaces of Each Size
0 10 20 30 40 50 60 W 80 90 100 200
Tons, Nominal Capacity of Firraac.e
FIG. 161.—Graphical Comparison of Air Valve Areas of Various Open-hearth
heated steam, and its amount is considerable, particularly with
large furnaces. In " The Heat Balance of the Open-Hearth/'
by Sidney Cornell (Chemical and Metallurgical Engineering, May,
1913), the weight of moisture passing in the flue gases was given
as about 26 per cent of the weight of ingots produced. The water
seals in the valves increased the amount of moisture in the pro-
ducer gas 1 per cent.
The water seal depends upon its water supply, and a very slight