IMPROVEMENTS IN FURNACES
Year: 1879

page_text: LETTERS PATENT to William Pinkney, of Egglestone, in the County of
Durham, Engineer, for the Invention of "IMPROVEMENTS IN FURNACES."
PROVISIONAL SPECIFICATION left by the said William Pinkney at the
Office of the Commissioners of Patents on the 9th May 1879:
"
WILLIAM PINKNEY, of Egglestone, in the County of Durham, Engineer. IM-
PROVEMENTS IN FURNACES."
My Invention relates to the furnaces of steam boilers and to other furnaces, and
consists of arrangements whereby part of the air passing to the fire is heated, and
when heated is directed partly into the body of the furnace, and partly among the
inflamable but unburnt gases passing therefrom, which gases are thereby consumed
instead of being allowed to pass by the chimney into the atmosphere as usual.
In applying my Invention to puddling furnace and other similar furnaces, and to
the furnaces of marine and egg-ended boilers, and Lancashire, Cornish, or Galloway
boilers, and other similar boilers, I form around the fire hole door a casing having
at the outer and lower part an opening or openings for the admission of air, and
having at the upper and inner part an opening or openings for the exit of the air,
which becomes heated in passing through the said casing, the inlet openings being
provided with doors or slides by which the amount of air allowed to pass away
may be regulated, and I use hollow fire bars (preferably formed in halves) which
bars are open at their front ends to the atmosphere, and communicate at their rear
ends either directly or by means of a flue with a hollow fire bridge formed at the
back of the furnace, which fire bridge is perforated at the upper part and is
provided with an inlet or inlets for cold air; the said inlet or inlets being covered
by doors or slides by which the entrance of the cold air may be regulated as
required; I also arrange doors or slides before the open ends of the fire bars by
which the amount of air entering them may be regulated. For convenience in
stoking I leave a slit between the lower part of the fire door, or the lower part of
the casing around the said door and the upper part of the fire bars, through which
slit the poker may be introduced without opening the door when it is necessary to
stir the fire. I provide the lower part of the fire bridge with a door to admit of

page_text: access to the interior of the said fire bridge when necessary. The action of this
arrangement is as follows:-The air entering the fire door casing becomes heated
and descends from the exit apertures of the said casing into the fire. The air
entering by the hollow fire bar passes from them into the fire bridge, becoming
heated in its passage, and escapes therefrom by the apertures in the upper part
thereof, and on escaping meets and mixes with the inflamable gases passing over
the said bridge and insures their combustion.
When it is necessary or desirable to have a dead plate in front of the fire bars,
and flush with the lower part of the fire door or the fire door casing, I form at the
under part of the said bars and near their front ends orifices for the entrance of air,
the said orifices being provided with doors or slides for the purpose hereinbefore
described.
In applying my Invention to vertical boilers I dispense with the fire bridge, and
instead of it I form a chamber at the back of the fire place with which chamber the
hollow fire bars communicate, and I form flues at the sides of the fire place and an
annular chamber beneath the boiler, the said flues forming communications between
the said back chamber and the said annular chamber, which is perforated to allow
of the passage therefrom into the furnace of the air which has become heated in
passing through the hollow fire bars, and back chamber, and side flues. I prefer to
leave a slit or opening between the lower part of the door or door casing and the
fire bars for the purpose hereinbefore described. The said door casing is provided
with inlet and outlet apertures, the former being covered by doors or slides as in
the arrangement hereinbefore described.
In applying my Invention to the furnaces of locomotive engines, I so arrange the
front and back plates of the fire door that air may enter beneath the front or outer
plate, and pass up between it and the inner or back plate, over which it passes into
the fire box, the said air being thus heated before entering the fire box.
The space below the front plate of the fire door, through which space air enters, is
provided with doors or slides for the purpose hereinbefore described; I use hollow
fire bars at the under sides, and near the front ends of which are formed mouth-
pieces, the said mouthpieces being preferably so arranged as to face in the direction
in which the engine runs, which mouthpieces I provide with doors or slides for the
purpose herein before described. At the back of the fire box below the boiler tubes
I form a chamber with which the hollow fire bars communicate, and I form in the
said chamber apertures through which the air entering by the fire bars passes out
into the fire box, meeting and mixing with the inflamable gases as they enter the
tubes, and thus insuring the combustion of the said gases.
By my Invention the draught is quickened, smoke is prevented or much lessened,
fuel is economized, and the labour of stoking is greatly reduced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Pinkney in the Great Seal Patent Office on the 8th
November 1879.
WILLIAM PINKNEY, of Egglestone, in the County of Durham, Engineer. "IM-
PROVEMENTS IN FURNACES."
My Invention relates to the furnaces of steam boilers and to other furnaces, and
consists of arrangements whereby part of the air passing to the fire is heated, and
when heated is directed partly into the body of the furnace and partly among the
inflammable but unburnt gases passing therefrom, which gases are thereby consumed
instead of being allowed to pass by the chimney into the atmosphere as usual.
In applying my Invention to puddling furnaces and other similar furnaces,"
and to the furnaces of marine and egg-ended boilers and Lancashire, Cornish,
or Galloway boilers, and other similar boilers, I form around the fire hole
door a casing having at the outer end lower part an opening or openings for the
admission of air, and having at the upper and inner part an opening or openings
for the exit of the air which becomes heated in passing through the said casing, the
inlet openings being provided with doors or slides by which the amount of air
allowed to pass may be regulated, and I use hollow fire bars (preferably formed in
halves), which bars are open at their front ends to the atmosphere and communicate
at their rear ends either directly or by means of a flue with a hollow fire bridge
formed at the back of the furnace, which fire bridge is perforated at the upper part
and is provided in the case of metallurgical furnaces with an inlet or inlets for cold
air, the said inlet or inlets being covered by doors or slides by which the entrance
of the cold air may be regulated as required. I also arrange doors or slides before
the front ends of the fire bars by which the amount of air entering them may be
regulated. For convenience in stoking I leave a slit between the lower part of the
fire door or the lower part of the casing around the said door and the upper part
of the fire bars, through which slit the poker may be introduced without opening
the door when it is necessary to stir the fire. I provide the lower part of the fire
bridge with a door or doors to admit of access to the interior of the said fire bridge
and the flue beyond it when necessary.
Figure 1 of the accompanying Drawings is an elevation of part of a metallurgical
furnace to which my Invention is applied; Figure 2 is a vertical section taken on
the liue 1, Figure 1; Figure 3 is a horizontal section taken on the line 2, Figure 1;
and Figure 4 is a vertical section taken on the line 3, Figure 3. In these and in
the other Figures of the Drawings the same letters and figures of reference indicate
the same parts. A is the fire door casing and a' is the fire door; a, a, are the
inlet openings by which air passes into the said casing; a³ is the outlet opening by
which the air passes from the casing into the furnace; and at is the sliding door or
plate by which the amount of air entering the casing is regulated, the said plate
having openings a³, a³, formed in it, and being supported by pins a, a, passing
through slots a, a, which admit of the said plate being slidden so as to bring the
openings a, a, in it over or partly over the openings a, a, in the casing A; B, B,
are the hollow fire bars, which I prefer to cast in halves, as shown; b¹ is the flap
by which the openings at the front ends of the said bars may be closed or partly
closed, as required. The said flap is jointed at the upper parts by pins 62, b³,
formed thereon and passing through eyes or staples 63, 63; b is a ratchet formed on
or affixed to one of the said pins; and b is a bolt capable of sliding vertically in
staples 6, 66, the lower end of which bolt engaging with the teeth of the said
ratchet holds the said flap at the inclination necessary to admit the required amount
of air to the furnace bars, the said flap being liberated by raising the bolt 65 when
it is required to shut off the supply of air to the bars B, B; C is the flue with
which the said bars communicate at their rear ends, and D is the hollow fire bridge.

page_text: with which the flue C communicates; d' is a perforated plate forming the top of
the fire bridge, through which the air entering by the fire bars passes out into the
furnace; d² is the inlet for cold air covered by a sliding plate d³; d' is a door, by
removing which access may be gained to the interior of the fire bridge D when
necessary; E is the slit between the lower part of the fire door casing and the
upper part of the fire bars, through which slit the poker may be introduced to stir
the fire, without opening the fire door.
The action of this arrangement is as follows:-When the sliding plate a' and the
flap bare adjusted so as to uncover the openings a², a², in the fire door casing A
and fire bars B, B, air enters the said casing and becomes heated in passing through
it, and descends from the exit aperture a³ into the furnace. Air also enters by the
hollow fire bars B, B, and passes from them into the flue C, and thence into the
fire bridge D, becoming heated in its passage and escapes therefrom by the
apertures in the plate , and on escaping meets and mixes with the inflammable
gases passing over the said bridge and insures their combustion. When it is
necessary or desirable to have a dead plate in front of the fire bars and flush with
the lower part of the fire door or fire door casing, I form the front ends of the said
fire bars so that the openings therein may be below the said dead plate, the said
openings being provided with doors or slides for the purpose herein before described;
Figure 5 of the accompanying Drawings is a longitudinal section of a portion of a
furnace in which the fire bars are thus arranged. In this Figure, 67 is the front
end of one of the bars, and 68 is the dead plate. The flap 61 by which the mouths
of the bars may be closed, or partly closed, is retained in the required position by
the pawl or catch b° which engages with the teeth of the ratchet b¹.
Figure 5a of the accompanying Drawings is a front elevation; Figure 6 is a
transverse section, and Figure 7 is a longitudinal section of the furnace of an egg-
ended boiler, showing the application of my Invention thereto. As the combustion
of the gases in furnaces constructed according to my Invention is much more com-
plete than in ordinary furnaces I prefer to have return flues instead of mere flash
flues, except in the case of very long boilers, in order that the great increase of heat
obtained by the use of my furnaces may be thoroughly utilized; Figure 8 is a trans-
verse section of the furnace of an egg ended boiler with return flues. The only
points of difference between this arrangement and that hereinbefore described with
reference to Figures 1, 2, 3, and 4, are that the fire bars communicate directly with
the fire bridge, that the front ends of the said bars are provided with a sliding
plate having openings b, b, formed in it instead of with a hinged flap, and that the
door for admitting cold air to the fire bridge is dispensed with.
Figure 9 is an end elevation of a double flued Cornish boiler to which my
Invention is applied, the fire door casing and the flap covering the fire bridge
being removed from one of the furnaces; Figure 10 is a longitudinal section of part
of the said boiler, the section being taken on the line 4 Figure 9. In this arrange-
ment the flap covering the outer ends of the fire bars is adjusted so as to cover or
uncover the openings in the said bars by sliding it longitudinally in the eyes or
staples 63, 63. The plate b¹ covering the openings a² in the casing A is similarly
arranged. The bearers supporting the fire bars and fire bridge have feet d³, d³,
formed on them, and are connected by rods do, do, which prevent the shifting of the
said bridge. A door or shutter d is placed under the fire bridge beyond the
opening therein to admit of access to the flue beyond it; and lugs 610, 610, having
holes formed in them are cast on the underside of each half of the fire bars, through
which holes pins are passed, which prevent the said half bars from being warped
by the heat of the fire on them. In other respects this arrangement is similar to
those herein before described.
Figure 11 is a front elevation, and Figure 12 is a section taken on the line 5,
Figure 11, of part of a marine boiler, the furnaces of which are constructed
according to my Invention. The fire door casing and flap covering the fire bars are
omitted from one of the furnaces in the elevation in order the better to show the
arrangement of fire bars each of which is formed with a branch 6¹¹ near its rear

page_text: end, through which a current of air passes when the sliding plate 6' is adjusted so
as to admit air to the said bars. The said plate in this arrangement is supported
by and slides in grooved brackets or guides 612, 612.
In applying my Invention to vertical boilers I dispense with the fire bridge, and
instead of it I form a chamber at the back of the fire place, with which chamber
the hollow fire bars communicate; and I form flues at the sides of the fire place
and an annular chamber beneath the boiler, the said flues forming communications
between the said back chamber and the said annular chamber, which is perforated,
to allow of the passage therefrom into the furnace of the air which has become
heated in passing through the hollow fire bars and back chamber and side flues.
I prefer to leave a slit or opening between the lower part of the door or door
casing and the fire bars for the purpose herein before described. The said door
casing is provided with inlet and outlet apertures, the former being covered by
doors or slides, as in the arrangement hereinbefore described.
Figure 13 is a front elevation of a vertical boiler and furnace to which my
Invention is applied; Figure 14 is a longitudinal section of the said furnace taken
on the line 6, Figure 13; Figure 15 is a transverse section thereof taken on the
line 7, Figure 14, the portion of the boiler shown in Figures 14 and 15 being in
elevation; Figures 16 and 17 are horizontal sections taken respectively on the lines
8 and 9, Figure 13. F is the chamber formed at the back of the fire place with
which the hollow bars B, B, communicate; G, G, are the flues formed at the sides
of the fire place; and H is the annular chamber with which the flues G, G, com-
municate by means of short flues g¹, g₁; h', ', are the openings formed in the
annular chamber H, through which the heated air from the fire bars B, B,
chamber F, and flues G, G, g¹, gl, pass to and mingle with the gases from the fuel
as they enter the tubes of the boiler. The arrangement of the fire door casing is
similar to that herein before described.
In applying my Invention to the furnaces of locomotive engines I so arrange the
front and back plates of the fire door that air may enter beneath the front or outer
plate, and pass up between it and the inner or back plate over which it passes into
the fire box, the said air being thus heated before entering the fire box. The space
below the front plate of the fire door, through which space air enters, is provided
with a door or flap for the purpose hereinbefore described. I use hollow fire bars
at the under sides, and near the front ends of which are formed mouth pieces, the
said mouth pieces being, preferably, so arranged as to face in the direction in which
the engine runs, which mouth pieces I provide with a flap, or doors, or slides, for
the purpose herein before described. At the back of the fire box below the boiler
tubes I form a chamber with which the hollow fire bars communicate, and I form
in the said chamber apertures through which the air entering by the fire bars
passes out into the fire box, ineeting and mixing with the inflammable gases as
they enter the tubes, and thus ensuring the combustion of the said gases.
Figure 18 of the accompanying Drawings is a longitudinal section of part of tho
boiler and the fire box of a locomotive engine, showing the application of my
Invention thereto, and Figure 19 is a section taken on the line 10, Figure 18. a
is the outer plate; and a* is the inner plate of the fire door. To the lower part of
the plate al a flap a is jointed at a¹º, a¹o, by opening which air may be allowed to
enter under the plate a', the air so entering passing up between the plates a¹, and
a*, and over the said plate a* into the fire. The flap a³ may be kept open to the
required extent by passing a chain attached thereto over a hook projecting from
the plate a', as illustrated in Figures 20 and 21, Figure 20 being an enlarged
front view of the said door and flap, and Figure 21, a vertical section of the front
plate of the said door and the flap; or any other suitable arrangement may be
used. 61, 61, are the mouth pieces formed on the under sides of the fire bars B,
the said mouthpieces being carried by a flap b" jointed at 615, and connected by a
lever 616 to a rod 617, which passes through and projects above the foot plate;
618, 618, are teeth formed on the said rod, by engaging one of which teeth with a
tooth 61 affixed to the foot plate, the said flap 61 may be kept open to the required

page_text: extent; I is the chamber into, which the air, entering by the fire bars passes; and
,, are the apertures whence the said air issues to mingle with the gases from
the fire as they enter the tubes; is a flap by raising which any dust which may
collect in the chamber I may be discharged.
Instead of forming the chamber I at the back of the fire box the rear ends of the
bars may be turned up so as to direct the air passing through them to the boiler
flues. Figure 22 is a plan of a fire bar thus formed; and Figure 23 is an elevation
of one half such bar.
By my Invention the draught is quickened, smoke is prevented, or much
lessened, fuel is economized, and the labour of stoking is greatly reduced.
Having thus described the nature of my Invention of "Improvements in
Furnaces" and the manner in which it is to be performed, I wish it to be under-
stood that I do not limit myself to the precise details herein before described, as
they may be varied without departing from the nature of my said Invention.
But I claim as my said Invention,-
Firstly. The combination with a furnace in which hollow fire bars communi-
cating with a hollow perforated fire bridge are used, of a hollow fire door casing in
which openings are formed for the entrance and exit of air, essentially as herein-
before described and illustrated in Figures 1, 2, 3, 5ª, 7, 9, 10, 11, and 12 of the
accompanying Drawings.
Secondly. The improvements in the furnaces of vertical steam boilers herein-
before described, with reference to Figures 13, 14, 15, 16, and 17 of the accom-
panying Drawings, that is to say, arranging in the said furnaces hollow fire bars
which communicate with flues or chambers by which heated air is caused to pass
to and mingle with the gases from the fire as they enter the flue or flues of the
boiler, essentially as described.
Thirdly. The combination with a furnace of a vertical steam boiler, of a hollow
fire door casing in which openings are formed for the entrance and exit of air,
essentially as hereinbefore described and illustrated in Figures 13, 14, and 16 of
the accompanying Drawings.
Fourthly. The use in the furnaces of locomotive engines provided with arrange-
ments for directing heated air to and causing it to mingle with the gases from the
fire as they enter the boiler flues of a fire hole door, the plates of which are so
arranged that air may be allowed to enter under the outer plate and pass between
it and the back plate, and pass over the said back plate into the furnace, essentially
as hereinbefore described and illustrated in Figures 18, 20, and 21 of the accom-
panying Drawings.
In witness whereof, I, the said William Pinkney, have hereunto set my hand
and seal, this Sixth day of November, in the year of our Lord One
thousand eight hundred and seventy-nine.