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Full text of "The Flow Of Gases In Furnaces"

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without encountering any obstruction to delay it and flows into
the space below the dome. Accordingly, the rising column of
flaming gases passes upward without filling the combustion
chamber and is surrounded by an atmosphere of unburned rela-
tively colder gases, through which it passes. Direct observation
of the combustion of blast furnace gas in the Cowper hot-blast
stove shows that, as the ratio between the gas and the air supply
approaches the theoretical requirements, combustion ceases to
be silent and becomes noisy. The flame commences to jet out
around the gas burner in bursts, indicating a temporary extinguish-
ment of the flame in the combustion chamber, which is immediately
filled with a comparatively cold explosive mixture.

Everything indicates that the correct location for the combus-
tion chamber of the Cowper stove is the dome or space above the
checkerwork. The streams of flame which are produced cannot
pass directly out of this chamber, but are held under the dome,
heating its walls from below. The dome forms a permanent
firebox for their combustion. Below the dome of the Cowper
stove, therefore, there is a stationary hot zone, which burns those
portions of the gases which have not been utilized in the combus-
tion chamber, as soon as they come into contact with the heated
chamber. For these reasons the construction of a Cowper stove
with the combustion chamber
located elsewhere than in
the dome is fundamentally

However, if the gas and
the air are simply introduced
above the checkerwork of
the stove, as is shown in
Fig. 72, there is evidently
danger that a portion of the
cold gas and air, in place of
entering into the reaction of
combustion and forming a
flame, will drop down to the
bottom of the stove, through                        FIG. 72.

the checker openings, just as

a heavy liquid will sink downward through a light liquid. In
order to prevent this occurrence, which is undesirable and