IMPROVEMENT
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Sigismund Schuman at the
Office of the Commissioners of Patents on the 18th September 1883.
SIGISMUND SCHUMAN, of Glasgow, in the county of Lanark,
IN BOILER FURNACES,"
"IMPROVEMENTS
The object of this Invention is to effect more complete combustion of the fuel
consumed in the furnaces of steam boilers thereby preventing the emission of
smoke. To that end such furnaces are fitted with the improved appliances
hereinafter described.
According to one modification of the Invention as adapted for the furnaces of
Cornish, Lancashire or other boilers having horizontal flues, a considerable space is
left between the ordinary fire grate and the bridge, and in this space are fitted a
series of shaped air ducts or tubes which may be formed of cast iron or of fire
brick or fire-clay and which rise vertically in front of the bridge and at the upper
end rest on the bridge.
These air ducts convey hot air to the back of the bridge from an air space
formed below and at the inner end of the fire grate, the air being warmed in
passing along below the grate and being directed and partially confined by means
of an oscillating door or doors. The air ducts or tubes are formed with flanges or
projecting lips which form a continuation of the fire grate, and on which part of
the incandescent fuel may rest, and the ducts or tubes are fitted at some distance
apart to leave between them open channels which also serve for conveying hot air
over the bridge. Below the air ducts and channels is fitted a transverse steam
pipe on which are a series of nozzles arranged to direct jets of steam upwards into
the ducts and channels, and over these jets may be fitted curved spray plates
which tend to spread the steam, and also prevent the choking up of the steam jets
by dust.
The steam which is taken from the boiler at any convenient point by a pipe may
be superheated by leading the supply pipe in close proimity [sic] to the fire-grate,

page_text: and it is directed into the ducts and channels partly with the object of injecting
currents of the heated air through them, and partly that by its decomposition in
passing through the incandescent fuel and through the highly heated air ducts in
front of the bridge, and by the combustion of the resulting gases, the smoke and
unburnt particles of fuel passing over the bridge may be consumed.
Beyond the ordinary bridge and within the flue is built a wall composed of fire
bricks or blocks of refractory material which are so disposed as to leave between
them a large number of interstices or openings through which the hot gases from
the furnace may pass. This perforated wall is heated to incandescence by the
flame and escaping hot gases. When the fire is freshly charged with coal, the
smoke produced mingles with the heated air, led in by the ducts and channels and
striking against this perforated wall which acts as a heat regenerator is caused to
burn.
A second bridge is built or formed at some distance behind this regenerator,
and in the combustion chamber which is formed between them any smoke passing
through the interstices of the regenerator is consumed, air being supplied in a
heated state by a few of the air ducts which are carried over the fire bridge and
extend to or beyond the regenerator. A second regenerator of similar construction
is in some cases fitted behind the first and between it and the second bridge; and
one or more of the hot air ducts may be carried back to or beyond this wall.
The amount and the period of admission of steam to the ducts and channels
may be controlled by a valve fitted in the supply pipe, but by a further
improvement the admission of steam is controlled automatically by the opening
and closing of the furnace door. For this purpose the steam supply pipe is led in
close proximity to the door and is fitted with a valve which is operated by a lever
or handle resting on the door or on a projection on it. A very limited quantity of
steam is however supplied independently of the action of the door, the amount
being regulated by a separate cock or valve.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Sigismund Schuman in the Patent Office on the 17th March 1884.
SIGISMUND SCHUMAN, of Glasgow, in the county of Lanark,
"IMPROVEMENTS
IN BOILER FURNACES,"
The object of my said Invention is to effect more complete combustion of the
fuel consumed in the furnaces of steam boilers thereby preventing the emission of
smoke. To that end such furnaces are fitted with the improved appliances
hereinafter described and illustrated in the accompanying drawings. In the
drawings figure 1 is an end elevation partly in section; figure 2 a longitudinal
vertical section; and figure 3 a horizontal section of a two flued boiler, showing
my improvements applied. Figures 4 and 5 are a front elevation and a sectional
side elevation of details.
According to one modification of the Invention as adapted for the furnaces of
Cornish, Lancashire, or other boilers having horizontal flues F, a considerable space
is left between the ordinary fire-grate A, and the bridge B, and in this space are
fitted a series of L shaped air ducts or tubes C which may be formed of cast iron
or of fire-brick or fire clay and which rise vertically in front of the bridge B, and
and at the upper end rest on the bridge.
These air ducts convey hot air to the back of the bridge B from an air space
formed below and at the inner end of the fire grate A, the air being warmed in
passing along below the grate and being directed and partially confined, if desired,
by means of an oscillating door or doors. The air ducts or tubes C may be formed
with flanges or projecting lips which form a continuation of the fire-grate, and on
which part of the incandescent fuel may rest, but such projections may be
dispensed with. The ducts or tubes C are fitted at some distance apart, or kept
apart by distance pieces, to leave between them open channels which also serve for
conveying hot air over the bridge. Below the air ducts and channels is fitted a
transverse steam pipe G on which are a series of nozzles or orifices arranged to
direct jets of steam upwards into the ducts and channels C, and over these jets may
be fitted curved spray plates which tend to spread the steam and also prevent the
choking up of the steam jets by dust. Over the steam pipe G, openings are
formed, with air ducts into which are fitted open tubes E which direct upwards
the steam and air to meet the flames. The steam, which is taken from the boiler
at any convenient point by a pipe G may be superheated by leading the supply
pipe in close proximity to the fire-grate A, and it is directed into the ducts and
channels C partly with the object of injecting currents of the heated air through
them, and partly that by its decomposition in passing through the incandescent
fuel and through the highly heated air ducts in front of the bridge, and by the
combustion of the resulting gases, the smoke and unburnt particles of fuel passing
over the bridge may be consumed.
Beyond the ordinary bridge B, and within the flue F, is built a wall H
composed of fire-bricks or blocks of refractory material which are so disposed as to
leave between them a large number of interstices or openings h through which
the hot gases from the furnace may pass. This perforated wall is heated to
incandescence by the flame and escaping hot gases. When the fire is freshly
charged with coal, the smoke produced mingles with the heated air led in by the
ducts and channels and striking against this perforated wall, which acts as a heat
regenerator, is caused to burn. The regenerator may be supported on an arch
which may be filled with loose bricks while the boiler is in use, but which may be
conveniently removed for cleaning out the flues.

page_text: A second bridge I is built or formed at some distance behind this regenerator,
and in the combustion chamber which is formed between them any smoke passing
through the interstices of the regenerator H is consumed, air being supplied in a
heated state by a few of the air ducts C which are carried over the fire bridge B
and extend to or beyond the regenerator H. A second regenerator H₁ of similar
construction is, in some cases, fitted behind the first and between it and the second
bridge I; and one or more of the hot air ducts C may be carried back to or beyond
this wall H¹
•
The amount, and the period of admission, of steam to the ducts and channels C
may be controlled by a valve e fitted in the supply pipe G. The admission of
steam may be controlled automatically by the opening and closing of the furnace
door. For this purpose the steam supply pipe is led in close proximity to the
door J of the furnace and is fitted with a valve which is operated by a lever or
handle resting on the door or on a projection on it. A very limited quantity of
steam may however be supplied independently of the action of the door, the amount
being regulated by a separate cock or valve.
In the horizontal section figure 3, one flue F is shown fitted with air tubes over
the bridge, while the other flue shows at one side a number of tubes separated by
L shaped bars C² and also a number of such bars alone. The L shaped bars C¹
which may be used in substitution of the tubes C, or along with them are shown
to a large scale in figures 4 and 5. They are fitted over the bridge B and are
separated by ribs c or distance pieces up between which air passes and is discharged
at orifices c¹ above. A portion of the heated air passes through the recesses or
ducts formed between such bars and passes out at their rear ends at the back of
the bridge B. A steam pipe G is fitted in a transverse opening formed through
the bars C, and is formed with jets or orifices through which steam is injected
through the tubes E which are fitted in sockets formed between pairs of bars."
Having now particularly described the nature of my said Invention, and in what
manner the same is to be performed, I declare that what I claim is,—
First. The arrangement of parts forming the improved boiler furnace herein
described and illustrated.
Second. The arrangement over the fire bridge of a boiler furnace, of the air
ducts, tubes or channels in combination with a steam pipe supplying jets of steam,
substantially as herein described and illustrated.
Third. The arrangement within a boiler furnace flue of a perforated wall or
regenerator fitted behind the fire bridge, substantially as and for the purpose herein
set forth.
In Witness Whereof, I the said Sigismund Schuman have hereunto set my
hand and seal this fifteenth day of March, in the year of our Lord One thousand
Eight hundred and Eighty four.