IMPROVEMENTS IN APPARATUS USED FOR HEATING STEAM BOILERS
Year: 1876

page_text: LETTERS PATENT to Joseph Firth, of St. John's, Dewsbury, in the County of
York, Builder, for the Invention of "IMPROVEMENTS IN APPARATUS USED FOR
HEATING STEAM BOILERS."
Sealed the 7th November 1876, and dated the 13th June 1876.
PROVISIONAL SPECIFICATION left by the said Joseph Firth at the Office
of the Commissioners of Patents on the 13th June 1876.
JOSEPH FIRTH, of St. John's, Dewsbury, in the County of York, Builder. "IM-
PROVEMENTS IN APPARATUS USED FOR HEATING STEAM BOILERS."
This Invention relates to the heating of steam boilers by the combustion of gases
produced in gas generators separate from the steam boiler furnaces or combustion
chambers. The gas generator I employ is in many respects similar to that used
with the well known Siemens' furnace. The fuel is fed through openings fitted
with lids into a hopper, from which it passes on to an inclined plane and thence on
to a grate vertically above which is a brick arch to radiate heat on to the top of
the fuel.
The gases produced in the generator are led off by a vertical flue of brickwork,
from the top of which they are conducted by a downward flue to a horizontal flue
leading to a valve chamber from which flues pass to the steam boiler furnace. A
damper is placed in the upright flue from the generator to shut off gas from the
steam boiler furnace whenever required. From the horizontal gas flue leading to
the valve chamber there is also a branch flue leading to the chimney of the steam
boiler furnace; this flue is ordinarily closed by a damper, but in case of the water
level getting too low in the boiler, or on other emergency, the gas can be led
directly to and consumed in the chimney or the flue leading to it. This connection
of the gas flue with the chimney also allows of any tar which may collect in the
gas flues being from time to time burnt off and carried away directly by the
chimney. At the top of the gas generator I also form a man-hole, covered with a
loose lid to avoid all possibility of injury to the generator in case of the gas
becoming ignited in the gas flues before arriving at the boiler furnace.
The steam
boiler, if it be a cylindrical one without interval flues, I mount above the top of

page_text: two pairs of what are known as regenerators and form a flue or combustion
chamber below the whole of the lower half of the boiler. One pair of regenerators
serve for heating the gas and the air with which it is to enter into combustion as
they pass to one end of the flue beneath the boiler, whilst the other pair of
regenerators is heated by the gases escaping from the opposite end of the flue.
passing through them on their way to the chimney, and these chambers when
sufficiently heated serve in turn as heating chambers for the gas and air, when the
products of combustion are led off to the chimney through the first pair of chambers
as is well understood.
The streams of gas and air after being conducted through either pair of regene-
rators are led off by four or other number of flues from each regenerator, and the
air flues and gas flues are brought together in pairs at different heights into one.
or other end of the flue or combustion chamber below the boiler. The boiler is
supported by brickwork resting upon the crowns of the arches of two of the
regenerators, and on the crown of the arch covering the space by which the pairs
of regenerators are separated one from the other.
In place of the arrangement above described the regenerators may be dispensed
with and gas and air flues be similarly led into one end of the combustion chamber
or flue below the boiler, whilst the products of combustion are led off from the
opposite end of this flue to the chimney. Or, if the boiler is constructed with
internal flues the gas and air may be led into one end of the flues, whilst the
products of combustion are led off from the opposite end to flues leading along both
sides of the exterior of the boiler to a flue below the boiler and from thence to the
chimney.
By heating steam boilers in the manner above described the production of smoke
is entirely avoided whilst at the same time there is a great saving of fuel, and as
a greater heat can readily be obtained in the boiler furnace more steam can be
generated with a given size of boiler, consequently there will be a saving of outlay
in the number of boilers required and the boiler flues will remain comparatively
clean as the ash from the solid fuel will remain in the gas generator.
Boilers already set can, if the regenerators are not used, be readily adapted to
being heated in the manner above described without disturbing the setting of the
boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Firth in the Great Seal Patent Office on the 12th December
1876.
JOSEPH FIRTH, of St. John's, Dewsbury, in the County of York, Builder.
PROVEMENTS IN APPARATUS USED FOR HEATING STEAM BOILERS."
"
IM-
This Invention relates to the heating of steam boilers by the combustion of gases
produced in gas generatiors separate from the steam boiler furnaces or combustion
chambers.
Figures 1, 2, 3, 4, 5, and 6 represent my arrangement for heating steam boilers
where regenerators are employed together with the generator for the combustible
gases to be employed therein."
Figure 1 is a longitudinal section through the boiler furnace or combustion
chamber and regenerators.
Figure 2 is a part elevation of boiler end with dotted lines shewing gas and air
flues leading from regenerators to the boiler furnace or combustion chamber, also
transverse section through the regenerators, valve chamber, and valves, and the
generator.
Figure 3 is a plan of regenerator foundations with valve seats and channels
or passages from the gas and air valves to the regenerators, and part plan of
chimney flue.

page_text: Figure 4 is a sectional plan of top of regenerator arches shewing openings for the
outlet of gas and air from the regenerators to the upright flues leading to the boiler
furnace or combustion chamber.
Figure 5 is a sectional plan shewing top of boiler end and side portions of the
boiler furnace or combustion chamber and the flues which supply the boiler furnace
or combustion chamber with gas and air in combination.
Figure 6 is a side elevation shewing part of boiler, the outside of brickwork of
boiler furnace or combustion chamber with the ironwork for bolting the same
strongly together, and a longitudinal section of valve chamber and valve, sections
of channels or passages for supply of gas to valve, for supply of gas from valve to
regenerators, and sections of chimney flue.
Similar letters indicate similar parts in all the Figures.
A is the boiler, which is cylindrical without internal flues, which I mount above
the top of two pairs of regenerators marked B1, B2, B3, B4, each consisting of a
chamber built of fire-brick, which chambers are filled with fire-bricks or other
refractory material c¹, c², c³, c, in such a manner as to leave small spaces between
the bricks. These regenerators are arched over at the top, and with the arch D
covering the space by which the pairs of regenerators are separated one from the
other support the bed a of the boiler furnace or combustion chamber which extends
below the whole of the lower half or more of the boiler.
Communications are established between the top of the four regenerators B¹, B³,
B³, B, and the boiler furnace or combustion chamber E in the following manner :-
The regenerator B¹ communicates with the boiler furnace or combustion chamber at
the point C through the passages F, F, F, F, while the regenerator B2 communi-
cates with the boiler furnace or combustion chamber at the same point C through
the passages F, F2, F2, F2; in a similar manner the regenerator B³ communicates
at the point C with the boiler furnace or combustion chamber through the passages
F, F, F, F, whilst the regenerator B* communicates with the boiler furnace or
combustion chamber at the same point C¹ through the passages F, F, F, F¹
At these points C and C¹ the passages F¹ and F, as also those F and F, are
separated from each other by vertical division walls till they reach the various
levels indicated in Figure 2. Each of the regenerators B1, B2, B3, B4, is provided
below the loosely piled brickwork c¹, c, c, c, with openings G², G², G³, G; by
means of these the regenerators B1 and B' communicate alternately with the hori-
zontal gas flue H leading from the gas generator, which will be hereafter described,
and with the passage I leading to the chimney.
These alternate communications are regulated by the reversing valves h and i in
the following manner-If the valve h is in the position indicated in Figure 6 then
combustible gas from the generator will pass through the channel or passage J and
will enter the regenerator B¹ through the aperture G¹; if at the same time the
valve i is in the same position as h then atmospheric air will enter into the
regenerator B through the channel or passage Js and aperture G².
If the
regenerators B¹ and B have been previously heated by the hot products of com-
bustion passing through them then the currents of air and gas in passing up through
the small spaces between the bricks will become heated. Arrived at the top of the
regenerators they will be conducted through the passages F¹ and F to the point C,
where on rising up between the vertical division walls to the different levels shewn
on Figure 2 they will unite, and on being ignited will evolve an intensely hot
flame, which passes across the boiler furnace or combustion chamber and imparts
its heat to the boiler. Arrived at the other end of the boiler furnace or combustion
chamber the hot product of combustion pass downwards through the passages F's
and F into the regenerators B³ and B*; here on passing downwards through the
mass of loosely piled bricks these latter absorb the greater part of the heat of the
gases, and they issue in a comparatively cold state through the apertures G³ and G
into the channels or passages Js and J, whence the reversing valves h and i being
in the position indicated they are conducted through the flue I to the chimney
shaft, when by the continued passage of the hot products of combustion the regene-

page_text: rators B³ and B* have become heated to a considerable degrce the position of the
valves h and i is reversed by means of the levers X, X; combustible gas will now
enter into the regenerator B*, and atmospheric air into the regenerator B³. These
currents of gas and air on passing up through the regenerators will become heated,
and on emerging from them at the point C will mix, will become ignited, and the
hot products of combustion after traversing across the boiler furnace or combustion
chamber will pass down at C through the regenerators B1 and B2, imparting to
them the greater part of their heat, and thus each pair of regenerators will serve
alternately to absorb the heat from the products of combustion and then give off
this same heat again to the gas and air serving to produce this combustion.
The boiler is supported by blocks of fire-brick work K, K, K, resting upon the
crowns of the arches of the regenerators B and B and on the crown of the
arch D, covering the space by which the regenerators are separated one from the
other. Through the latter of these blocks of fire-brick passes the blow-off pipe L
by which the boiler is emptied when required. Upon the top of the boiler is placed
the man-hole M for access into boiler.
The combustible gases are produced in the gas generators by the partial com-
bustion of fuel which is fed through the hoppers N. From these hoppers the fuel
passes on to an inclined plane O of fire-brick or other refractory material, and
thence on to a fire-grate P vertically above which is the fire-brick arch Q, which
when heated serves to radiate heat on to the top of the fresh fuel. The com-
bustible gases thus produced are led off by the vertical flue of brickwork R, from
the top of which they are conducted by a downward flue S to the horizontal flue H
leading to the valve h from which channels or passages pass to the boiler, furnace,
or combustion chamber, as already described. A damper U is placed in the upright
flue from the generator to shut off the gas from the steam boiler when required.
The lids of the valves h and i, which are raised and lowered by means of levers,
pullies, and chains, also assist in regulating the supply of gas and air respectively.
From the horizontal gas flue H leading to the valve chamber there is also the branch
upright flue V leading to the chimney flue. This branch fluc is ordinarily closed
by the damper W, but in case of the water level getting too low in the boiler, or
any other emergency, the gas can be led directly to and consumed in the chimney or
the flue I leading to it. This connection of the gas flue with the chimney also allows
of any tar which may collect in the horizontal gas flue H being from time to time
burnt off and carried away directly by the chimney. At the top of the gas
generator I also form a man-hole covered with a loose lid Y to avoid all possibility
of injury to the generator in case of the gas becoming ignited in the gas flues
before arriving at the boiler furnace or combustion chamber.
Figures 7, 8, 9, and 10 represent one of my arrangements for heating steam
boilers where regenerators are not employed.
Figure 7 is a plan of valve seats, hot air flues, and channels or passages leading
from gas and air valves to the boiler furnace or combustion chamber.
Figure 8 is a transverse section of boiler and boiler furnace or combustion
chamber.
Figure 9 is a section shewing gas and air valves, channels or passages to gas
and air valves, and from gas and air valves to boiler and side elevation showing
part of boiler, the outside of boiler, furnace, or combustion chamber with dotted
lines indicating channel or passage by which hot air is supplied to the air valve.
Figure 10 is a transverse section of valve chamber, gas valve channels, or
passages for supply of gas from valve to boiler, furnace, or combustion chamber,
supply of hot air to air valve and from air valve to boiler, furnace, or combustion
chamber, also end elevation of outside of boiler, furnace, and part of boiler end.
In this arrangement combustible gas from the generator will pass through the
horizontal gas flue H to the gas valve h, thence along the channel or passage J¹
through the apertures F¹, FI, F, F, in the arch of the channel or passage J¹ to
the boiler, furnace, or combustion chamber into which it is discharged at different
levels, as shewn in Figure 2; J³, Js, are air flues, which are formed in the bed of

page_text: the boiler, furnace, or combustion chamber E, and are separated from the latter by
air-tight fire-clay divisions. These air flues communicate with the outer atmosphere
at the further end of the boiler, and the supply of cold air to the air flues is
regulated by the damper Z. The air on its passage through the air flues J³, J³, to the
air valve becomes heated by the hot flame in the boiler, furnace, or combustion
chamber. From the air valve i the heated air passes along the channel or passage
J2 through the apertures F2, F2, F2, F2, in the arch of the channel or passage J2 to
the boiler, furnace, or combustion chamber into which it is discharged at different
levels in the manner shewn in Figure 2. At these points the gas and air unite,
and on being ignited will evolve an intensely hot flame, which passes across the
boiler, furnace, or combustion chamber, imparting its heat to the boiler and to the
air in the flues J³, Js. The products of combustion are then led off by the flue to
the chimney, which is not shown on the Drawings. Where regenerators are not
employed, and there being therefore no necessity to reverse the currents, the
reversing levers are not required, the quantities of gas and air respectively passing
through the valves and i being regulated by raising and lowering the valve lids
by means of levers, pulleys, and chains.
Figures 11 and 12 represent my arrangement for heating steam boilers which are
constructed with internal flues.
Figure 11 is a longitudinal section of the boiler, part of valve chamber, arch,
vertical flues leading from gas and air valves to boiler, internal flue of boiler, loosely
piled fire-bricks, bottom and end flue of boiler and damper leading from bottom flue
of boiler to chimney flue.
Figure 12 is a transverse section of boiler, shewing internal tubular flues, with
loosely piled fire-bricks, side flues, bottom flue, and flues by which hot air is
supplied to the air valve.
In applying my arrangement for heating steam boilers to those which are con-
structed with internal tubular flues the arrangements for the supply of combustible
gas and air are precisely the same as those last described, excepting that instead of
discharging the gas and air in four or more pairs of jets at different levels into the
combustion chamber below the boiler I discharge them in two pairs at the same
level, one pair into each internal tubular flue, at which points the gas and air unite,
and on being ignited will evolve an intensely hot flame, which passing along the
internal tubular flues B amongst the loosely piled brickwork Cx with which these
flues are partially or entirely filled imparts its heat to that portion of the boiler;
the products of combustion are led off from the opposite end along the flues C, C, on
both sides of the exterior of the boiler, imparting heat to that portion of the boiler
and to the air in the flues J3, J³, and thence to the flue D below the boiler, and
thence to the chimney flue, the entrance to which is controlled by the damper E.
Boilers already set can if the regenerators are not employed be readily adapted to
being heated in the manner above described without disturbing the setting of the
boilers.
Having thus described the nature of my Invention, and the best means I am
acquainted with of performing the same, I wish it to be understood that I do not
confine myself to the precise details of the various arrangements as shown on the
accompanying Drawings, but what I claim is,-
First. The heating of steam boilers by means of combustible gas and air in
combination discharged at different levels in four or more pairs of jets into each
end alternately of the boiler, furnace, or combustion chamber, extending below the
whole of the lower half or more of the cylindrical boiler without internal flues.
Second.. The heating of atmospheric air to be used in combination with com-
bustible gas by means of flues in the bed of the furnace or combustion chamber
separated therefrom by air-tight fire-clay divisions.
Third. The heating of steam boilers constructed with internal tubular flues, with
gas and air in combination, which passes amongst loosely piled brickwork with
which the internal flues are partially or wholly filled, which brickwork on becoming

page_text: heated serves to intensify the heat passing through it, heating the atmospheric air
which is required to support combustion in the manner previously mentioned.
In witness whereof, I, the said Joseph Firth, have hereunto set my hand and
seal, this Thirteenth day of November, in the year of our Lord One
thousand eight hundred and seventy-six.