IMPROVEMENTS IN AND CONNECTED WITH FURNACES FOR MELTING GLASS, ALSO APPLICABLE TO OTHER FURNACES.” PROVISIONAL SPECIFICATION
Year: 1880

page_text: LETTERS PATENT to David Warren and James Warren, of the Firm of
Messieurs Thomas Warren and Sons, Milton Glass Works, Glasgow, in the
County of Lanark, North Britain, for an Invention of "IMPROVEMENTS IN
AND CONNECTED WITH FURNACES FOR MELTING GLASS, ALSO APPLICABLE TO
OTHER FURNACES.”
PROVISIONAL SPECIFICATION left by the said David Warren and James
Warren at the Office of the Commissioners of Patents on the 11th December
1880.
DAVID WARREN and JAMES WARREN, of the Firm of Messieurs Thomas Warren
and Sons, Milton Glass Works, Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN AND CONNECTED WITH FURNACES FOR MELTING GLASS, ALSO
APPLICABLE TO OTHER FURNACES."
This Invention relates to certain improvements in and connected with furnaces
for melting glass, also applicable to other furnaces of the reverberatory class, and it
has for its object to effect more complete combustion of the fuel or gases generated
and obtain increased heat therefrom, while the reverberatory flame at an extremely
high temperature is directed with great energy on the molten glass or other
material under treatment, and thereby time and fuel are economised in the heating
or melting process.
The Invention consists essentially in introducing a blast of heated air at one or
more points in the crown or roof of the furnace to combine with the flame from
the fire-grates, and create a most intense heat directly over the surface of the glass
or other material on the hearth. In glass furnaces and other reverberatory furnaces
hitherto in use, and in which a blast of air has been employed to force combustion, the
air has been admitted either above or through the fire-grate, and the oxidised flame
is usually carried over the bridge into the melting furnace, after it has parted with
a considerable amount of its heat both to the bridge and to the upper surface or
crown of the furnace from which it reverberates. By this means the bridge and
upper part of the furnace are crumbled and worn away unduly and require periodic

page_text: renewal or repair, whilst the flame cannot be well directed over the entire surface
of the molten material, and a great part of its heat is lost and passes away to the
chimney. By introducing the heated air at sufficient velocity through the crown
of the furnace, the flame strikes the molten material at the moment of combination
of the hot gases and air, or when the temperature is at its highest point, the main
part of the heat being utilised effectively. The crown of the furnace is also kept
comparatively cool, and the flame passing from the fire-grate to the hearth is of
much lower temperature than usual.
Under one modification of the improvements as applied to a glass furnace, the
arched crown of the furnace is pierced with a number of opening, which are
preferably formed by leaving out bricks in building the arch or crown. These
openings may however be fitted with nozzles of refractory material, and be directed
vertically downwards or towards the centre of the arch. A single large flue or a
series of flues leading into these openings are formed above the arch or crown, and
these flues are heated preferably by waste heat from a hot flue formed above, and
through which the waste products of combustion are led from the furnace. The
air flues or passages are thus heated by waste hot gases passing above them, and
also by radiation or absorption of heat from the crown of the furnace. The air for
supplying the furnace is forced through these flues by a "Root's" blower or other
blowing engine, and is sufficiently heated in its passage to the furnace.
The admission of the heated air to the furnace may be controlled partly by
regulating the speed or power of the blowing engine, and partly by the opening or
closing of sliding or other plates or valves, which would be operated by handles or
levers outside to partially cover or uncover the inlet air orifices.
"
"
The reverberatory flame is led in the usual way from fire-grates on each side,
which are preferably close furnaces fed automatically by a Frisby or other
automatic feeding apparatus from below, no air being admitted excepting as much
through the fire-grate as is necessary to maintain slow combustion.
In combination with the improved furnace described part of the residual hot
gases or flame may be directed through flues or openings into calcining chambers
outside, in which the raw materials for the manufacture of glass may be roasted or
prepared for the subsequent melting process, as is common in connection with the
older constructions of glass furnaces.
In applying the improvements to other furnaces, as for treating iron or steel, or
for calcining ores, or for the preparation of soda ash and similar substances, the
arrangement and construction of the furnace may be substantially as described,
with the heated air forced in either from above or from the side, but with the
hearth and other parts arranged as usual to suit the special circumstances.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Warren and James Warren in the Great Seal Patent
Office on the 10th June 1881.
DAVID WARREN and JAMES WARREN, of the Firm of Messieurs Thomas Warren
and Sons, Milton Glass Works, Glasgow, in the County of Lanark, North Britain.
"IMPROVEMENTS IN AND CONNECTED WITH FURNACES FOR MELTING GLASS, ALSO
APPLICABLE TO OTHER FURNACES."
Our said Invention relates to certain improvements in and connected with
furnaces for melting glass, also applicable to other furnaces of the reverberatory
class, and it has for its object to effect more complete combustion of the fuel
or gases generated, and obtain increased heat therefrom, while the reverberatory
flame at an extremely high temperature is directed with great energy on the molten
glass or other material under treatment, and thereby time and fuel are economised
in the heating or melting process.
The Invention consists essentially in introducing a blast of heated air at one or
more points in the crown or roof of the furnace to combine with the flame from
the fire-grates, and create a most intense heat directly over the surface of the glass
or other material on the hearth.
In glass furnaces and other reverberatory furnaces hitherto in use, and in which
a blast of air has been employed to force combustion, the air has been admitted
either above or through the fire-grate, and the oxidised flame is usually carried
over the bridge into the melting furnace after it has parted with a considerable
amount of its heat, both to the bridge and to the upper surface or crown of the
furnace from which it reverberates. By this means the bridge and upper part of
the furnace are crumbled and worn away unduly, and require periodic renewal or
repair, whilst the flame cannot be well directed over the entire surface of the
molten material, and a great part of its heat is lost and passes away to the
chimney. By introducing the heated air at sufficient velocity through the crown
of the furnace, the flame strikes the molten material at the moment of combination
of the hot gases and air, or when the temperature is at its highest point, the main
part of the heat being utilized effectively. The crown of the furnace is also kept
comparatively cool, and the flame passing from the fire-grate to the hearth is of
much lower temperature than usual.
Under a modification of the improvements as applied to a glass furnace, the
arched crown of the furnace is pierced with a number of openings, which are
preferably formed by leaving out bricks in building the arch or crown. These
openings may, however, be fitted with nozzles of refractory material, and be directed
vertically downwards or towards the centre of the arch. A single large flue or a
series of flues leading into these openings is or are formed above the arch or crown,
and these flues are heated, preferably, by waste heat from a hot flue formed above,
and through which the waste products of combustion are led from the furnace.
The air flues or passages are thus heated by waste hot gases passing above
them, and also by radiation or absorption of heat from the crown of the furnace.
The air for supplying the furnace is forced through these flues by a "Root's
blower or other blowing engine, and is sufficiently heated in its passage to the
furnace.
The reverberatory flame is led into the glass furnace in the usual way from a
fire-grate or fire-grates on each end or side, which are preferably close furnaces fed

page_text: automatically by a "Frisbie " or other automatic feeding apparatus from below,
little air being admitted excepting as much through the fire-grate as is necessary to
maintain slow combustion.
In applying the improvements to other furnaces, as for treating iron or steel or
for calcining ores, or for the preparation of soda ash and similar substances, the
arrangement and construction of the furnace may be substantially as described,
with heated air forced in either from above or from the sides, but with the hearth
and other parts, such as calcining chambers, arranged as usual to suit the special
circumstances.
And in order that our said Invention, and the manner in which the same is to
be performed may be more fully understood, we shall now describe the two Sheets
of explanatory Drawings which we have hereunto appended for that purpose, and
which represent modifiactions of onr improvements as applied to a glass furnace
and a steel furnace. The same reference letters are used in these Drawings to
indicate the same or like parts where repeated.
Figure 1, on Sheet 1, of the Drawings is a transverse vertical section, and
Figure 2 is a longitudinal vertical section of part of a glass furnace constructed in
accordance with our Invention. Figure 3 is a horizontal section of part of the
same furnace, taken as at the line 1--1, in Figure 1, to show the hot air flues and
air openings in the crown of the furnace, and Figure 4 is a horizontal section
taken as at the line 2--2, in Figure 2, and showing the construction of the flues
through which the hot waste gases pass from the furnace to the chimney, and also
showing a calcining chamber fitted in connection with the furnace.
Figure 5 on Sheet 2 of the Drawings is a longitudinal vertical section, partly
broken away, of a steel melting or smelting furnace constructed in accordance with
our Invention. Figure 6 is a transverse vertical section of the same, and Figure 7
is a horizontal section on the line 3--3 in Figure 5 of part of the furnace.
Referring to Sheet 1 of these Drawings, our improved glass furnace is formed
with the usual tank T in which the glass is melted over a strong bed T' of refractory
material kept cool by a series of horizontal air flues f, having an inlet at f¹ from
the "cave over which the furnace is built, and discharging at f² near the bridge.
A slow combustion furnace F or cupola built with close walls and roof F¹ of fire-
brick or similar refractory material is formed at each end of the glass furnace or
tank T, and from each of these close furnaces the hot gases or flames pass over a
bridge B, and play over the surface of the glass, the bridge being built hollow or
with air flues or spaces b, through which a strong draught is maintained.
The furnace F is formed with a fire-grate F2 fitted preferably with "Frisbie "
feeding appliances, as indicated at F³, by which dross or solid fuel is fed into the
furnace from below. The flame resulting from the combustion of the fuel in the
furnace is of comparatively low temperature, and in passing over the bridge into
the glass furnace, does not have the injurious effect on the bridge and crown or
arch A which is usual. The hot gases or flames passing over the bridge B and
entering the furnace, are met by strong currents or blasts of heated air, which is
forced in through openings a formed in the crown or arch A of the furnace, and the
hot gases and hot air uniting and being blown down on to the surface of the melting
or molten glass in the tank T produce a most intense heat where required, while
the crown or arch A remains comparatively cool. The air thus supplied to the
glass furnace through the crown A is forced by means of a "Root's" blower or fan
through pipes P passing through the "cave to each side of the furnace, and
entering to the first divisions of long undulating flues a', a¹, formed over the arch A
at each side by a series of longitudinal baffle or division walls a² covered by thin
fire-clay slabs a³ laid or built over them. These flues a¹, a', are open at the
alternate ends, as shown particularly in Figure 3, and are divided by a longitudinal
partition a in the centre, and the air traverses the flues from end to end, as
indicated by the arrows, and towards the centre of the arch A, near which it
escapes through the openings a into the furnace. The air is heated in its course
"

page_text: through these flues a³, a¹, partly by radiant heat from the crown A of the furnace,
but mainly by the heat of the waste hot gases which escape through the working
holes or openings O by which the furnace is charged, and from which the molten
glass is withdrawn. The escaping hot gases are thence directed through archways
or openings g leading into long undulating flues g', over and similar to the air
flues a', as indicated particularly in Figures 1 and 4, and which are also formed by
division walls g² with openings in them to allow of the circulation of the gases, and
covered or roofed over with fire-clay slabs or flat bricks g³. The hot gases circulate
through the flues g³, as indicated by the darts in Figure 4, round the division
walls g² to the centre of the arch, where a longitudinal partition g' separates them,
and the waste gases after parting with a large proportion of their heat to the air
in the flue al beneath, escape by short chimneys G built over the last or central
channels at the termination of each flue, and at opposite ends of the furnace, thence
flowing into the main chimney or stalk S of the glass house, which is carried by
supporting pillars or columns D ranged round the furnace as usual.
The improved glass furnace has the usual calcining chambers C or "arches"
placed preferably at each of the four corners within the glass house, one only being
shown in Figures 2 and 4. Part of the residual hot gases or flames from the glass
furnace F pass by flue openings c into these chambers, and roast, calcine, or prepare
the raw material for the subsequent melting process in the manufacture of the glass.
Doors C and C² are provided for charging the calcining chambers, and with-
drawing the roasted material respectively, and the fumes or waste gaseous products
of combustion are carried away by large flues or flue tubes C³ from the roof leading
into the main chimney S.
In combination with the improved glass furnace the usual annealing ovens or
kilns may also be provided within the glass house, and the waste hot gases there-
from are led to the main chimney S by close flue pipes E.
The improved glass furnace described and shown is susceptible of considerable
modification in arrangement and construction of the various parts without departing
from the essential novel features of forcing or blowing in air through the crown or .
arch, and of heating the air in its course over the arch. The disposition of the air
flues a' and of the heating flues g' may also be varied, as, for example, by ranging
both series of flues horizontally alongside each other so that the air may be heated
by radiation of heat through dividing partitions of refractory material; but the
arrangement of flues shown in the Drawings is preferred, as having the advantage
that whilst the air is heated both from above and below, the arch or crown of the
furnace is partially cooled by the absorption therefrom of heat imparted to the
flowing air.
The heating furnaces F may also be of any other ordinary construction instead
of that shown, and although the improved glass furnace has been described as fitted
with a heating furnace at each end, a single large heating furnace only may be used,
particularly in glass furnaces in which the glass tank is not of large size.
Our present improvements are obviously applicable to glass furnaces of other
constructions than that described in reference to Figures 1 to 4, as, for example, to
furnaces for melting flint glass and the finer varieties of glass, which are usually
melted in pots instead of in a tank or open hearth. In such cases we prefer to
make the furnace circular in plan, and construct it with a "Frisbie " feeding furnace
or similar heating furnace in the centre and fed from below. The glass pots are ranged
radially round the heating furnace and within the arch or crown which covers the
whole. The waste hot gases from the furnace instead of at once escaping by the
usual flue openings to the chimney are made to pass by or through the working
holes and through archways to long undulating flues above the crown and imme-
diately over similar air flues formed between them and the crown of the furnace, as
in the glass furnace shown in the Drawings, the flues however being disposed to
suit the form of the crown in annular rings round the centre of the arch with radial
openings and divisions to cause the air and hot gases to travel a long course before

page_text: escaping. The waste hot gases escape by a chimney for each flue or by a single
chimney, while the air which is blown or forced in by a fan or blowing engine after
traversing the air flues and becoming heated escapes by openings in the crown by
preference formed radially round the heating furnace, the object of so directing the
heated air being to avoid the risk of cracking the pots by the air and flame striking
any part of them, while also ensuring complete combustion of the smoke and gases
as they leave the heating furnace.
A furnace for heating, roasting, or treating soda ash and similar material may
also be constructed as in the glass furnace last described, or formed with heating
furnaces on each side, or ranged radially round it, and with our improvements
applied thereto.
Referring to Sheet 2 of the Drawings, which represent our improvements as
applied to a steel melting or smelting furnace, the arrangement of the heating
furnace F and disposition of the flues for heated air, and for the waste hot gases,
are much the same as in the glass furnace represented in Figures 1 to 4, while the
hearth of the furnace T is constructed as in an ordinary steel furnace with a lined
cast iron shell T* supporting the siliceous bed of the hearth on which the metal M
is melted. The usual air space t is left between the working hearth T and the
built bed or bottom T¹ of the steel furnace. The furnace is provided with charging
doors N and puddling doors N¹ on either side, and with the usual plugged
opening for withdrawing the charge, and also with heating or calcining
chambers C fitted at the corners of the steel furnace. The flames and hot gases
from the heating furnaces, after they pass over the bridges B, B, are met by bot
air, which is forced or directed through the openings a in the arch or crown A.
This air is forced in by means of a fan or blower through a pipe P leading into the
flues a¹, where the air is heated by absorption of heat from the crown and by the
escaping waste hot gases from the furnace which are led through the flues g' above,
the flues a¹, g', being arranged and constructed as described in reference to Figures 1
to 4. The waste hot gases from the steel furnace are, however, led by special
flues, or, as is preferred, through the heating chambers C to the flues g¹ above the
crown. The hot gases enter the heating or calcining chambers C by an opening c,
strike against and partially heat the pig iron or other raw material used in the
manufacture of steel, which is placed on the floor of the chamber C, and
thence the hot gases escape by special flues g which lead into the first row on
each side of the heating flues g¹ above the furnace, as indicated in dotted lines in
Figure 7.
Having thus described the nature of our said Invention, and the manner in
which the same is performed, we wish it to be understood that we do not confine
ourselves to the precise details herein described or delineated, but what we believe
to be novel and original, and therefore claim as the Invention secured to us by the
herein before in part recited Letters Patent is,
First. In glass furnaces, steel furnaces, and furnaces for treating soda-ash, or for
roasting or calcining ores or other similar materials, the injecting, forcing, or
blowing in of heated air through the crown or arch of such furnaces, to combine
with and promote complete combustion of the hot gases from the fire grates or
heating furnaces connected therewith, and to direct the flame and produce an
intense heat over the surface of the glass or metal or other material on the hearth
or tank, the injected air being led through flues and heated by means of the waste
hot gases from the furnace, all substantially as herein described and as shown in the
accompanying Drawings.
Second. The arrangement and construction of glass furnaces and of steel furnaces
in which air is heated by waste heat in passing through flues a¹ formed over the
arch or crown A of the furnace, and is forced or directed through the arch or crown
to meet and combine with the hot gases or flames from a heating furnace or
furnaces F and produce an intense heat at the surface of the glass or metal in the

page_text: tank or hearth T, substantially as herein described in reference to the accompanying
Drawings.
In witness whereof, we, the said David Warren and the said James Warren,
have hereunto set our hands and seals, this Sixth day of June, in the
year of our Lord One thousand eight hundred and eighty one.
Witness,
WALLACE FAIRWEATHER, C.E.,
Of W. R. M. Thomson & Co.,
Patent Agents,
Glasgow.
DAVID WARREN.
JAMES WARREN.
(L.S.)
(L.S.)