Year: 1887

page_text: I, ARTHUR SCHREIBER, of 2 Sachsenalle, Dresden, Saxony, in the Empire of
Germany, Engineer, do hereby declare the nature of my said invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
The object of my invention is to effect improvements in the form and arrangement
of fire bars, and other parts of furnaces, for steam boilers and other purposes.
My invention relates to furnaces fitted with transverse fire bars, and formed with
an air passage at the back of the furnace in front of the bridge.
The front part of the furnace, for a short distance from the dead plate, is made
level, from whence the bars are made to rise in a curve, to the back of the furnace.
The latter bars are also raised at their centres, above the level of their ends,
and the lower edges of their webs are curved forward, for the purpose of
assisting the entrance of air from the ash pit.
An inverted bridge is built in the flue, a short distance behind the ordinary bridge,
to deflect and mix the heated gases, and render the combustion more perfect.
And in order that my said invention may be particularly described and ascertained,
reference is hereby made to the accompanying drawings, in which similar letters of
reference indicate corresponding parts.
Fig. 1 is a sectional elevation of my improved furnace, as fitted in the fire tube of
a steam boiler.
Fig. 2 is a transverse section of the same.
Fig. 3 is a horizontal section of one of the flues shewn in Figs. 1 and 2.
Fig. 4 is a front view of one half of a bar, drawn to a larger scale.
Fig. 5 is a cross-section of 4 bars, drawn to the same scale as Fig. 4.
Fig. 6 is a plan view, shewing the method of placing the bars together.
Fig. 7 is a sectional elevation, shewing the application of my invention to an
externally-fired steam boiler.
a is the ordinary dead plate. From 6 to c (Figs. 1 and 7) the bars are laid
horizontally, both longitudinally and transversely, and the sectional form of these
bars is shown in Fig. 1, and also at b¹, Fig. 5. From c to d the bars are made to rise

page_text: in a curve, both longitudinally and transversely. The sectional form of these bars is
shewn at c', Fig. 5. The longitudinal curve is shewn in Figs. 1 and 7. The
transverse curve is shewn in Figs. 2 and 4. The transverse rise of the bars, at their
centres, is graduated from a straight line at c to the before mentioned curve towards
the back of the furnace.
The lower edges of the curved bars, are formed as shewn in Fig. 1, and also as
shewn at e e, Fig. 5, to assist and direct the entrance of air from the ash pit.
Horizontal grooves ff, are formed in the upper parts of the fire bars, and vertical
grooves g g are also formed on one face, which thus provide distance pieces and air
passages between the bars, and horizontal air passages in their upper surfaces.
The bridge is built in the flue so as to leave a passage for the air, to supply the
necessary oxygen to the heated gases, and inflame the carbonic oxide by mixing
therewith; and, for effecting a more thorough intermixture of the gases the inverted
bridge is built in the flue, a short distance from the ordinary bridge h.
The fire bars are supported, in fire-tube boilers, in the manner shewn in
Figs. 1, 2 and 3. Angle irons k k are bent to fit the tube, the web being cut away
at 7, to facilitate the removal of ashes. The upper ends of the angle irons kk, are
fitted with brackets m m, carrying rails nn, which form the supports for the bars.
o is a cross rail which prevents, the bars falling over. backwards.
The fuel is laid thinly over the raised portions of the bars, and the smoke and
other unconsumed gases from the lower parts of the bars, ascend to and mix with the
flames from the more highly heated incandescent fuel in the centre.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what I
claim is
1. In the construction of steam boiler and other furnaces, the application and use
of fire bars, curved and arched, longitudinally and transversely, and otherwise
arranged substantially as herein before described and shewn on the drawings.
2. The manufacture and use of curved fire bars, either with or without the curved
lower edge e, and formed with air channels fg, substantially as herein before described
and shewn on the drawings.
3. The method of and means and appliances for supporting the fire bars in fire
tube boilers, substantially as herein before described and shewn on the drawings.
4. The general construction, arrangement and combination of the several and
respective parts, together forming my improvements in smokeless furnaces,
substantially as herein before described and shewn on the drawings.