IMPROVEMENTS IN THE FURNACES OF STEAM BOILERS
Year: 1880

page_text: LETTERS PATENT to Carl Pieper, Civil Engineer and Patent Agent, of
109-110, Gneisenau Strasse, Berlin, S. W. Prussia, for an Invention of
"IMPROVEMENTS IN THE FURNACES OF STEAM BOILERS." A communication
from Adolf Knaudt, Manufacturer, of Essen on the Ruhr, Prussia.
COMPLETE SPECIFICATION filed by the said Carl Pieper at the Office of the
Commissioners of Patents on the 21st April 1880.
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CARL PIEPER, Civil Engineer and Patent Agent, of 109-110, Gneisenau Strasse,
Berlin, S.W. Prussia. "IMPROVEMENTS IN THE FURNACES OF STEAM- BOILERS.'
A communication from Adolf Knaudt, Manufacturer, of Essen on the Ruhr,
Prussia.
On account of the advantages which hot air presents in comparison with cold air
for the purpose of supporting the combustion of fuel, it has repeatedly been tried
to heat by means of special apparatuses the air introduced into the furnaces of
steam-boilers; but the arrangements of this kind which have actually come into
use are too complicated for the purpose, and have found but little favour.
More recently a different arrangement has been applied, consisting in a sort of
retort or tube of fireproof material placed above or behind the grate, tho air circu-
lating lengthwise around this tube, and subsequently passing through the same
from its front end, together with the combustion-gases.
The object of this Invention is to arrange the inside furnace of a steam-boiler in
such a manner that combustible gases may be produced from the fuel lying on the
grate, and that the air serving to support the combustion of these gases is heated
in channels surrounding the furnace, and thereupon conducted in numerous jets into
the inside of the furnace or combustion space proper.
For this purpose the fire-box or flue c, which is to serve as furnace, is made of
corrugated plates, and provided inside with a lining of fireproof bricks, as shown
on the annexed Sheet of Drawings in Figures 1 and 2. The outer surface of the
lining is in contact with the projecting bends of the corrugations of the flue. A
series of peripherical channels c is thereby formed between the lining and the
corrugated plates. These channels communicate by their lower ends with the
ash-pit, and by means of holes m provided for in the lining with the interior of
the furnace. The lining rests on the beams d. o is a grate of ordinary design,
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page_text: and h an opening through which the fuel is introduced into the furnace during the
regular working of the boiler, the fuel being thrown in a thick layer on the grate,
and heaped up inside of the opening so as to keep it closed; i is a door which is
used only for lighting the fire and for clearing the grate from slags.
The air which has to maintain the combustion is forced by a blowing-apparatus
into the closed ash-pit. A part of the same thence passes upward through the
grate and into the fuel; and, as the latter forms a thick layer, as has already
been stated, its combustion will not be complete, so that combustible gases are
produced. The other part of the air enters into the channels c, is heated by the
contact with the hot living &, and then passes through the holes m into the inside
of the furnace for causing the combustion of the gases generated from the fuel,
and whose oxydation has not been completed.
While in the described furnace each channel e communicates by holes m with
the interior of the furnace. The channels e' of the front part of the furnace, shown
by Figs. 3 and 4, have no direct communication of this kind, but they are connected
with each other and with the first channel e by recesses p, so that the air may
pass from one channel e¹ to the other, and into the said channel e, whence it enters
into the furnace. The channels e in Figs. 3 and 4 are alike to those of Figs. 1
and 2.
A modification of this arrangement consists in causing one or more channels c'
to alternate with any number of channels e.
Having thus described the nature and object of this Invention, and the manner
in which it is to be carried out in practice as communicated to me by the inventor,'
I hereby claim as new and essential feature of the same,-
In a flue or a fire-box of a steam-boiler, which flue or fire-box is made of
corrugated plates, a lining of fire-proof bricks arranged in such a manner as to be
in contact with the projecting bends of the corrugations, the channels thereby
formed being open towards the ash-pit and communicating with the interior of the
fire-box, or partly with the latter and partly with each other, by means of holes
in the lining, substantially us and for the purpose specified.
In witness whereof, I have hereunto set my hand and seal, this Nineteenth
day of April, in the year of our Lord One thousand eight hundred and
eighty.
CARL PIEPER. (L.S.)