Improvements in and connected with Furnace Fronts for Steam Boilers.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with Furnace Fronts for Steam
Boilers.
I, JAMES HOWDEN, of 8, Scotland Street, in the County of Glasgow, North
Britain, Engineer, do hereby declare the nature of this invention to be as
follows, that is to say :-
My said invention has for its object to improve the construction of furnace
fronts, and of parts connected therewith, for steam boilers, the improvements
being designed principally for application with either "forced" or "suction
draught and with arrangements for heating the air.
In carrying out my invention I construct a hollow furnace front with vertical
inner and outer disk-like plates of steel or wrought iron, which are connected
partly by a curved shell plate bolted or riveted to them by means of flanges or of
angle iron and extending round the lower part. Various openings are cut or formed
in the vertical plates, such as those for the fire door and ashpit. A fire-door
passage is formed by a shell of steel or iron fixed between the vertical plates, and
an outer door is arranged, having fixed to it by studs an inner perforated air box.
The air enters the door passage through ports in its top, over which ports is fitted
a sliding valve plate; and this valve plate is made with or has in connection with
it vertical parts sliding against the inner vertical plate and controlling openings in
that plate into boxes fixed on the inside of the plate, these boxes, of which there
is one occupying the upper part of the furnace front, and two one on each side of
the fire door, have perforated inner sides, and they receive and distribute the
entering air. The upper part of the furnace front is in communication with the
casing or casings in which the air is heated. The passage of air to the lower part
of the furnace front and thence into the ashpit is controlled by valves at each side
of the fire-door passage.
An annular flanged piece or ring of steel or iron, cast or wrought is riveted or
otherwise fixed to the inner vertical plate to facilitate the adapting and fixing of
the furnace front to the furnace mouth. Or a casting may be substituted for more
or less of the inner vertical plate or of parts connecting the inner vertical plate to
the outer vertical plate. Or the entire furnace front may be built up of separate
plates or parts all or some of which may be cast or rolled.
The improved arrangement of the air-inlet valves and boxes hereinbefore
described is applicable with a furnace front entirely of cast iron or with one built
up in any suitable manner.
Dated this Fourteenth day of March 1896.
EDMUND HUNT,
Applicant's Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with Furnace Fronts for Steam
Boilers.
I, JAMES HOWDEN of 8 Scotland Street in the County of Glasgow North-
Britain Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :-
My said invention has for its object to improve the construction of furnace
fronts, and of parts connected therewith, for steam boilers the improvements being
designed principally for application with either "forced" or suction draught and
with arrangements for heating the air.
In carrying out my invention I employ a hollow furnace front having openings
for the fire door and ashpit and communicating with the casing or casings in which
the air to be forced or sucked into the furnace is heated. The air enters the fire-
door passage, the space in the furnace above the bars, and the ashpit through ports
controlled by valves, and for its better distribution in the fire-door passage, and in
the space in the furnace above the bars, perforated air boxes are placed there,
through which the air must pass.
And in order that my said invention and the manner of performing the same
may be properly understood, I hereunto append a sheet of explanatory drawings,
to be hereinafter referred to, and showing various modifications of my improved
furnace fronts for steam boilers.
Figure, 1, of the drawings is a front elevation of one modification of my
improved furnace front, Figure 2 being a horizontal section, Figure 3 a transverse
vertical section, and Figure 4, a longitudinal vertical section of the same.
Figures, 5, and 6, are respectively a transverse vertical section, and a longitudinal
vertical section of a second modification of my improved furnace front.
Figures, 7, and 8, are respectively a transverse vertical section and a longitudinal
vertical section of a third modification of my improved furnace front.
In these drawings the same reference letters and numerals are used to mark the
same or like parts wherever they are repeated.
In the modification shown in Figures, 1, 2, 3, and 4, of the drawings the bollow
front is constructed with a vertical inner disk-like plate, A and a vertical outer
disk-like plate, B, of steel or wrought iron, which are connected partly by a curved
shell plate, C, bolted or riveted to them by means of angle irons, D, or it might be
by flanges and extending round the lower part. Openings E, and G, are cut or
formed in the vertical plates, A and B, for the fire door E 1, and ashpit G 1. A
fire-door passage is formed by a shell, J, of steel or iron fixed between the vertical
plates, A and B, and the outer door has fixed to it by studs K, an inner perforated
air box L. The air enters the door passage through ports, M, in its top over
which ports is fitted a sliding valve-plate, N; and this valve plate, N, is made
with or has in connection with it vertical parts P, sliding against the inner vertical
plate, A, and controlling openings, Q, Q1 and Q2, in that plate, into boxes fixed
on the inside of the plate, these boxes of which there is one, R, occupying the
upper part of the furnace front, and two, R 1, and R 2, one on each side of the fire
door E1, have perforated inner sides and they receive and distribute the entering
air. The valve plate N, P, is moved by means of a spindle, N 1, and crank
handle, N 2, the spindle having on it an arm N 3, engaging with a projection N 4,
on the valve. The spindle, N°1, turns in bearings in the plates, A, and, B, and the
handle, N 2, is outside the outer one.
The upper part of the furnace front is in communication with the casing or

page_text: casings, S, in which the air is heated. The passage of air to the lower part of the
furnace front and thence into the ashpit, G 1, is controlled by valves, G 2, at each
side of the fire-door passage, these valves being moved by means of crank
handles, G 3, outside the outer plate, B.
An annular flanged piece or ring, T, of steel or iron cast or wrought is riveted
or otherwise fixed to the inner vertical plate, A, to facilitate the adapting and
fixing of the furnace front to the furnace mouth. Or a casting may be substituted
for more or less of the inner vertical plate, A, or of parts connecting the inner
vertical plate to the outer vertical plate, B. Or the entire furnace front may be
built up of separate plates or parts all or some of which may be cast or rolled.
The improved arrangement of the air-inlet valves and boxes hereinbefore
described is applicable with a furnace front entirely of cast iron or with one built
up in any suitable manner.
In the modification shown in Figures, 5, and 6, the ports M, Q, Q1, and Q2,.
are controlled by three separate valves NP, P 1, and P 2, instead of by one valve
piece as in the modification previously described. The valve piece, NP, is moved
horizontally and the valve pieces P 1, and P 2, are moved vertically between
guides, P 3, by links, P 4, and bell cranks, P 5, moved by means of an arm N 3,.
on a spindle, N 1, provided with a crank bandle, N 2. Parts of this modification
which are not described are constructed and arranged similarly to the corresponding
parts of the modification previously described.
In the modification shown in Figures, 7, and 8, a small auxiliary chamber is
formed between the plates, A, and B, by a flanged piece, V, which partly encircles
the fire-passage shell, J, and the ports M, Q, Q1, and Q2, communicate with this
chamber. This auxiliary chamber has three openings, V 1, on its top communi-
cating with the air casing, S, and these openings are controlled by a valve, N,
moved by means of a spindle N 1, au arm N 3, and a crank handle, N 2. Air
enters by the top openings, V 1, into the chamber, and passes thence by the
ports M, Q, Q1, and Q2, to the spaces above and below the fire bars V 2. Parts
of this modification, which are not described, are constructed and arranged
similarly to the corresponding parts of the modification first described.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. The construction, arrangement and combination of parts constituting the
improved furnace fronts for steam boilers, substantially as herein before described
with reference to Figures, 1, 2, 3, and 4, of the accompanying drawings.
2. The construction arrangement and combination of parts constituting the
improved furnace fronts for steam boilers, substantially as herein before described
with reference to Figures 5 and 6 of the accompanying drawings.
3. The construction arrangement and combination of parts constituting the.
improved furnace fronts for steam boilers, substantially as herein before described
with reference to Figures 7 and 8 of the accompanying drawings.
4. In a furnace front for a steam boiler, a series of openings or ports, controlled
by a valve or valves adjustable from the outside of the furnace front, the said
ports or openings communicating with the casing for introducing heated air, with
the furnace asbpit, and with perforated distribution boxes in the upper internal
part of the furnace or fire space, and in the passage to the fire space, substantially
as hereinbefore described and shown in the accompanying drawings.
Dated this Fourteenth day of December 1896.
EDMUND HUNT,
Applicant's Agent..