Improvements in the Fire Boxes or Combustion Chambers of Steam Boilers, more particularly those of Locomotive Engines for Effect- ing a more Perfect Combustion of the Fuel and Increasing the Heating Surface thereof.
Year: 1898

page_text: Date of Application, 14th Dec., 1898
Complete Specification Left, 12th Sept., 1899-Accepted, 14th Oct., 1899
Improvements in the Fire Boxes or Combustion Chambers of Steam
Boilers, more particularly those of Locomotive Engines for Effect-
ing a more Perfect Combustion of the Fuel and Increasing the
Heating Surface thereof.
I, JOSEF HENTSCHEL, of XI Simmeringer Hauptstrasse No. 57, Vienna,
Austria, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
Many attempts have been made for obtaining a combustion of fuel perfectly
free from smoke in locomotive engines and other boilers but no perfectly satis-
factory results have hitherto been obtained therefrom, as the apparatus or
arrangements employed have been, on the one hand, too complicated and exces-
sively sensitive, and liable to get out of order, while on the other hand they
required very careful attention.
The present invention relates to an improved construction of such fire boxes
or combustion chambers for the above named purpose which is distinguished
from those heretofore proposed mainly by its great simplicity and efficiency.
The essential feature of the invention consists in introducing the air required
for combustion entirely above the fuel on the fire grate and causing it by a baffle
to pass entirely downward through the fuel and grate.
The gases generated from the freshly fed fuel are in consequence hereof forced
to pass down through the lowermost incandescent layer of fuel, and are there
forced to enter into more or less perfect combustion with the air supply.
As by this arrangement the grate bars are subjected directly to the great heat
of combustion and are not cooled by the cool air supply entering from below,
as in ordinary furnaces, I construct the bars as tubes through which water from
the boiler is made to circulate, whereby at the same time the heating surface of
the boiler is greatly increased.
In carrying out my said invention I arrange across the inner part of the fire
box or combustion chamber a hollow transverse partition, constituting the before
mentioned baffle, and constructed of boiler plate, and whose interior com-
municates at top with the upper part of the water space of the boiler.
This partition extends down to below the inner end of the fire grate, which
latter is formed of a series of tubular bars inclining downwards from the front
end where they are made by any suitable means to communicate with the lower
part of the water space of the boiler, while at the inner end they are fixed to the
transverse partition so as to communicate with the lower part of the water space
thereof.
By this means an effective water circulation is set up through the tubular
bars and hollow baffle whereby they are protected from excessive heating, while
they afford a greatly increased heating surface to the boiler.
The circulation through the tubular bars may be facilitated by the insertion
of inner tubes therein.

page_text: The air required for combustion being admitted in regulated quantity through
the fire door above the fuel on the grate, it is forced by the hollow partition or
baffle to pass downward through the fuel and fire grate into the ash pit, whence
the combustion gases pass to the space behind the baffle and thence through the
fire tubes or internal flue of the boiler on their way to the uptake.
When applying the invention to the furnaces of existing boilers it is advisable
to protect the plates thereof forming the bottom of the ashpit against the great
heat of the flames and gases striking downwards from the grate, by means of a
layer of refractory material, such as a mixture of asbestos, graphite, fireclay and
water glass.
With new boilers on the other hand, the bottom of the ash pit is formed as
a water space communicating with the other water spaces of the boiler so as to
produce a circulation therein, and thus affording a still greater heating surface
for the boiler.
Dated this 14th day of December 1898.
ABEL & IMRAY,
Agents for the Applicant.
Improvements in the Fire Boxes or Combustion Chambers of Steam
Boilers, more particularly those of Locomotive Engines for Effect-
ing a more Perfect Combustion of the Fuel and Increasing the
Heating Surface thereof.
I, JOSEF HENTSCHEL, of XI Simmeringer Haupstrasse No. 57, Vienna,
Austria, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
-
Many attempts have been made, for obtaining a combustion of fuel perfectly
free from smoke in locomotive engines and other boilers but no perfectly satis-
factory results have hitherto been obtained therefrom, as the apparatus or
arrangements employed have been on the one hand too complicated and exces-
sively sensitive and liable to get out of order while ou the other hand they
required very careful attention."
The present invention relates to an improved construction of such fire-boxes
or combustion chambers for the above named purpose which is distinguished
from those heretofore proposed mainly by its great simplicity and efficiency.
The essential feature of the invention consists in introducing the air required
for combustion entirely above the fuel on the fire grate and causing it by a baffle
to pass entirely downward through the fuel and grate.
The gases generated from the freshly fed fuel are in consequence hereof forced
to pass down through the lowermost incandescent layer of fuel, and are there
forced to enter into more or less perfect combustion with the air supply.
As by this arrangement the grate bars are subjected directly to the great heat
of combustion and are not cooled by the cool air supply entering from below,
as in ordinary furnaces, I construct the bars as tubes through which water fron
the boiler is made to circulate, whereby at the same time the heating surface of
the boiler is greatly increased.
On the accompanying drawings are shewn by way of example some arrange-
ments for carrying out my said invention. Fig. 1 shews a longitudinal section
through the fire-box of a locomotive boiler, Fig. 2 shews a sectional plan, Fig. 3
shews a longitudinal section similar to Fig. 1 somewhat modified, and Fig. 4

page_text: shews a longitudianl section of the combustion chamber of an internally flued
boiler.
In all the arrangements a is the baffle or partition formed as a water space
and extending across the inner part of the fire box 6 of the locomotive Figs. 1
to 3 or combustion chamber c of the internal flued boiler Fig. 4.
The water space of this baffle is open at top and communicates there with the
upper water space of boiler.
The furnace bars are formed as tubes connected at their inner open ends to
the baffle a so as to communicate with the water space thereof while the front
open ends are connected either to the front water space e of the boiler as at
Figs. 1, 2 and 3, or to a transverse tube f connected at the ends to the side
water-spaces of the boiler in the case of the internal flued boiler Fig. 4.
For producing an effective circulation of the water through the tubular fire
bars they may have circulation tubes & inserted in them in the known manner.
The stoking of the fire is effected through the furnace door y through which
the air supply for the combustion also enters; for regulating the latter the
furnace door may be arranged to slide laterally so that it can be kept open to a
greater or less extent. The ashpit door h is always closed, and serves, as does also
the door i, only for the removal of the ashes.
As with this construction of fire box the flames strike downwards through the
fire grate, I prefer, in existing boilers, to line the bottom of the ash pit, as also
the inner end thereof with a refractory material, as shewn at Fig. 3, for which
purpose a mixture of asbestos, graphite, fireclay and water glass is best used, as
this mass is light, elastic and very refractory. In new boilers, on the other
hand, the ash pit bottom is also made to constitute a water space of the boiler,
as shewn in Fig. 1; in the case of internal flued boilers where the furnace is
inside the flue, as at Fig. 4, the ash pit bottom of course always constitutes a
water space.
By forming the ash pit bottom as a water space in the case of locomotive
boilers the heating surface of the boiler is still farther increased.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I claim is
A construction of fire box or combustion chamber for steam boilers, wherein
the air supply for combustion is introduced entirely above the fire grate and is
forced by a hollow transverse partition or baffle such as a through which the
water circulates, to pass downward through the fire grate and the fuel thereon,
the bars of the firegrate being constructed as water tubes and serving as
additional heating surface for the boiler, substantially as described.
Dated this 12th day of September 1899.
ABEL & IMRAY,
Agents for the Applicant.