I. VERTICAL REGENERATORS
The ordinary vertical regenerator is so constructed that it
should work in a rational manner; that is, the high-temperature
gases descend regularly and subdivide among the vertical passes
according to their temperature, while the air and gas which is
being heated subdivides into the ascending passes in the same
manner. This is why the idea of Schenwelder, of dividing each
of the checker chambers into two compartments, in order to secure
uniform working, is fundamentally wrong. He introduced into
regenerator construction a superfluous complication, and for this
reason his design has been abandoned.
Nevertheless, it should not be concluded from the above that
any sort of a vertical regenerator will always work in a regular
manner. Vertical regenerators have an inherent tendency to
work uniformly, but poor design may cause them to work in a
very irregular fashion.
For example, Fig. 50 shows a very common form of regenerator,
in which the current of
gas from the vertical flues
leading to the ports is
jetted upon the top of the
checkerwork. It is very
evident that in this case
it will be impossible to
secure uniform operation.
The checkerwork can only
work in a uniform man-
ner when sufficient space
is provided below the
arch over the chamber for
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the velocity of the gases to become zero or very close to zero.
The eddies, which are formed under too low an arch, disturb the
gas distribution and prevent the furnace from working uniformly.
In order to secure uniform results it is necessary to provide suf-
ficient space to absorb these eddy currents, in order that the
gases may enter the checkerwork with a very low velocity below
the arch over the chamber. As an example of a very good type
of regenerator we have shown the chamber of a 40-ton open-hearth
furnace at tho, plant of the Pennsylvania Steel Co., Fig. 51.