The Flow Of Gases In Furnaces

RELATION BETWEEN THE HEAD AND PRESSURE 37

So that, in the regenerator chamber, neglecting the resistance due
to surface friction, the pressure of the air will increase to

5.16-0.85 = 4 mm 31 of water.

The foregoing considerations being kept in mind, the working con-
ditions within the open-hearth furnace may be analyzed.

Fig. 23 shows a model reproducing the longitudinal vertical
section of an open-hearth furnace. This model is placed between
two sheets of glass and
immersed in a glass
tank filled with water;
colored kerosene is cir-
culated through the
model. The mechanics
of the circulation of
the gases within this
type of furnace are
clearly shown: the re-
generators by heating
the air and the gas
produce a positive hy-
drostatic pressure. It
is this pressure which
impresses their veloci-
ties upon the gases in
motion; it is com-
pletely absorbed in
overcoming the friction
in the uptakes, etc.,
and in producing the
velocity with which the
gases enter the heating
chamber of the furnace.
In the heating cham-
ber, the gases have a
very small velocity, and their hydrostatic pressure is, on the
average, equal to the pressure of the atmosphere, which must
be the case, by reason of the number of working doors and
openings.

The descent of the light gas through the uptakes and regen-

FIG. 23.