The Flow Of Gases In Furnaces

PREFACE TO THE FRENCH EDITION

THE researches of Professor Groume-Grjimailo bring to us a
new idea. Conceptions of this character are very rarely presented
to us in the numerous publications of the day, and we sincerely
compliment the author in that he has opened the way for us into
a very broad field which merits our careful consideration. He
has set forth a principle in regard to the circulation of the hot
gases within furnaces—a very simple principle, but one that has
not heretofore been recognized. We have always considered that
gases, by reason of their absolute elasticity, completely fill the
chamber in which they are enclosed. Then, by a process of
unconscious induction, without any sound basis, we conclude that
in circulating through a series of successive chambers or flues,
they fill equally the entire cross-section of those chambers through
which they pass and that their current sweeps uniformly through
all the passages or flues which are open to them in proportion to the
area of these passages. Perhaps we should not formulate this
erroneous principle in such exact terms; nevertheless, we pro-
ceed as though we firmly believed that it was correct. And it
certainly follows, notably in the construction of furnaces, that
very serious errors are made. Professor Groume-Grjimailo cites
numerous examples of these errors.
A phenomenon is more readily understood when it is compared
with something that we have always before us. Wo see a stream
of water flowing in its bed, resting upon the soil and bounded upon
three sides by the surface of the ground. Its upper surface is
separated from the atmospheric air above by a horizontal plane,
the position of which is not fixed and which varies in accordance
with the volume of water flowing. The hot gases in a furnace
tend to circulate in exactly the same manner, with this single
difference, that the plane of separation is below, and the profile
of the bed of the stream is formed by the roof and the walls of the
furnace. As this comparison shows, we have heretofore errone-
ously considered that the flame filled the entire furnace and heated