IMPROVEMENTS IN FURNACES FOR MELTING GLASS, WHICH FURNACES MAY ALSO BE USED FOR OTHER PURPOSES
Year: 1872

page_text: LETTERS PATENT to James Sheffield, of Glasgow,. in the County of
Lanark, North Britain, for the Invention of "IMPROVEMENTS IN
FURNACES FOR MELTING GLASS, WHICH FURNACES MAY ALSO BE USED FOR
OTHER PURPOSES.”
"
Sealed the 18th March 1873, and dated the 5th December 1872,
PROVISIONAL SPECIFICATION left by the said James Sheffield at the
Office of the Commissioners of Patents, with his Petition, on the
5th December 1872.
I, JAMES SHEFFIELD, of Glasgow, in the County of Lanark, North
Britain, do hereby declare the nature of the said Invention of "IMPROVE-
MENTS IN FURNACES FOR MELTING GLASS, WHICH FURNACES MAY ALSO BE USED FOR
OTHER PURPOSES," to be as follows, that is to say :—
This Invention which relates to improved arrangements of that class
of furnaces for melting glass (and which may also be used for melting
or heating other substances) wherein gas is employed as fuel, and the
heat of the waste products of combustion is utilized for heating the air
burnt with the gas in the furnace, consists in dividing the furnace
beneath the tank or receptacle wherein the glass is contained by a par-

page_text: tition wall, on cach side of which is arranged a series of vertical or
horizontal flues. Through one set of these flues on each side of the
partition wall the waste products of combustion pass on their way to the
chimney, and through another set or sets alternating therewith the air
passes, which becomes heated in passing through them by the heat
given up from the waste products of combustion. The air after being
thus heated passes up through a flue or flues situated at each end of the
furnace, at the top of which flue or flues it becomes mixed with gas
passing from a gas producer, one of which is preferably placed at
each end of the furnace and the gas is ignited. The waste products of
combustion from both ends of the furnace meet at the centre of the
combustion chamber, and pass off through a flue or flues constructed at
cach sido thereof, one of which leads downwards into the series of vertical
or horizontal flues on one side of the partition wall, whilst the other leads
into the similar series of flues at the opposite side of the partition wall.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Sheffield in the Great Seal Patent Office
on the 2nd June 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
SHEFFIELD, of Glasgow, in the County of Lanark, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of December, in the year
of our Lord One thousand eight hundred and seventy-two, in the 36th
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said James Sheffield, Her special license, that I,
the said James Sheffield, my executors, administrators, and assigns,
or such others as I, the said James Sheffield, my exccutors, adminis-
trators, or assigns, should at any time agree with, and no others,
from time to time, and at all times thereafter during the term herein
expressed, should and lawfully might make, use, exercise and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for “IMPROVEMENTS IN FURNACES FOR
MELTING GLASS, WHICH FURNACES MAY ALSO BE USED FOR OTHER PURPOSES," upon
the condition (amongst others) that I, the said James Sheffield, by

page_text: by an instrument in writing under my hand and seal, should particu-
larly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Sheffield, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say:―
My said Invention relates to improved arrangements of that class of
furnaces for melting glass (and which may also be used for melting or
heating orther substances) wherein gas is employed as fuel, and the heat
of the waste products of combustion is utilized for heating the air burnt
with the gas in the furnace.
And in order that my said Invention may be properly understood I
now proceed more particularly to set forth the system, mode, or manner
in or under which the same is or may be used or practically carried into
effect, reference being had to the two explanatory Sheets of Drawings,
that is to say :—
On 'Sheet 1 of the Drawings hereunto appended, Figure 1 is a longitu-
dinal section of one arrangement of the improved furnace, constructed
in accordance with this Invention. Figure 2 is a transverse section
thereof on the line x, x, Figure 1, whilst Figure 3 is a transverse section of
the same on the line Z, Z, Figure 1. As shewn by these Figures the
furnace is constructed with a tank or receptacle A. at its upper interior
part, into which the glass to be melted or the material of which the
glass is to be made is or are placed. The furnace is divided beneath the
tank or receptacle A by a partition wall B as shewn more particularly at
Figure 1, on one side of which is a series of vertical flues C, whilst on
the other side is a similar series of flues C¹. At each end of the furnace
a gas producer D is situated, from which the gas is conducted into the
tank or receptacle A through flues E; the waste products of combustion,
which meet at the centre of the combustion chamber, being conducted
by flues F and F respectively, to the first of the series of vertical
flucs C and C', into which they pass by means of openings O and O¹

page_text: respectivly situated at opposite sides of the furnace, as shewn more par-
ticularly at Figure 3 of the Drawings. The series of vertical flues C
and C¹are traversed by the waste products of combustion in the
direction indicated by the arrows towards the ends of the furnace,
where they enter return passages or flues G and G¹ respectively, leading
to openings H, through which they escape to the chimney or chimnies.
Situated in each of the flues C and C¹, with the exception of the two
first, or those two first entered by the waste products of combustion, are
a series of pipes or ducts I and I' respectively, through which the
supply of air necessary to maintain combustion of the gas in the
furnace is conducted, and in passing through which the air becomes
heated by taking up the heat given off by the waste products of com-
bustion before mixing with the gas from the gas producers D. The air
is admitted through openings J situated near the ends of the furnace as
shewn at Figure 1, and passes into the series of pipes or ducts I and I'
furthest from the partition wall B, which pipes or ducts I and I³ dis-
charge it into chambers L situated underneath the tank or receptacle A,
from which it passes down through another series of the pipes I and I' into
chambers M, placed at the lower part of the furnace, and so on in the
direction of the arrows until the side flues N and N' respectively are
reached, at the extremities of which the air mixes with the gas from the
producers D and becomes ignited. The flues F and F which conduct
the waste products of combustion from the combustion chamber are
constructed with an air space P between the flue and the side of the
furnace as shewn at Figure 3, in order to prevent the sides of the
furnace being burnt. The end walls Q of the furnace are also provided
with air spaces d as shewn at Figure 1, the air passing through which
prevents the end walls from being burnt. The gas producers D are pro-
vided with dampers ƒ by means of which the supply of gas may be
regulated or cut off entirely from the furnace.
Figure 4 represents a longitudinal section of an arrangement of
furnace with horizontal flues; Figure 5 is a part horizontal section
thereof on the line 6, b, Figure 4, whilst Figure 6 is a transverse section
of the same on the line c, c, Figure 4. As shewn by this arrangement,
the waste products of combustion from the tank E enter through the a
openings G, and G³, respectively, and pass in the direction of the arrows
through a set of flues A, one of which sets is situated at each side of
the partition wall B to the openings C leading to the chimney or

page_text: "
chimnies, whilst the air enters at the openings F, and passes in the
opposite direction up through another set of flues D to the flues H
leading to the combustion chamber and tank E, the flucs A and D alter-
nating with each other as shewn. In order to allow of the heated air
entering the combustion chamber above the gas the flues H cross alter-
nately with the gas flues I from the gas producers, as shewn more
particularly at Figures 4 and 5.
On Sheet 2 of the Drawings, Figure 1 is a longitudinal section of
another arrangement of the furnace in which the pipes or ducts through
which the air passes are arranged horizontally; Figure 2 is a horizontal
section thereof on the line a, a, Figure 1, whilst Figures 3 and 4 are
transverse sections on the lines b, b, and c, c, respectively, Figure 1.
Under this arrangement the furnace is constructed with a chamber A
situated at the centre of the furnace into which the waste products of
combustion are conducted from the flues O through the openings B.
The waste products of combustion pass from the receptacle A by
means of openings C into chambers D, one of which is situated at
.each side of the receptacle A, and from thence are conducted by means
of openings E to the chimney or chimnies. Placed within the
chambers D are. a series of horizontal pipes or ducts F which commu-
nicate at either end with air chambers G. The cold air enters at the
openings H, and in traversing upwards through the pipes or ducts F in
the direction indicated by the arrows becomes heated, and is finally-
discharged in a highly heated state into the flues I leading to the com-
bustion chamber J. Gas producers K are situated at the ends of the
furnace as shewn. The gas is conducted through flues L and enters
the combustion chamber J below the heated air by means of openings M,
when it becomes mixed with the heated air and is ignited.
At Figure 5 is shewn in longitudinal section a modified arrangement of
furnace in which the gas and heated air enter the combustion chamber
at the central part of the sides of the furnace. Figure 6 is a horizontal
section thereof on the line d, d, Figure 5, whilst Figure 7 is a transverse
section on the line e, e, Figure 5. As shewn by this arrangement the
waste products of combustion are conducted from each end of the com-
bustion chamber and tank A by flues B, which pass downwards at the
four corners of the furnace. The waste products of combustion pass
from the flucs B through openings O into chambers D situated at each

page_text: end of the furnace from whence they are conducted through openings E
into the chambers F, containing horizontal pipes I, escaping thence to
the chimney or chimnies through the openings G. The cold air enters
by the openings H, and after traversing upwards through the pipes or
ducts I, is discharged into the air chambers J, from which it passes
through the flues K into the combustion chamber and tank A. A gas
producer L is situated at each side of the furnace, the gas passing
through flues M to the combustion chamber A.
It is to be understood that although in each of the arrangements of my
improved furnace illustrated in the two annexed Sheets of Drawings the
gas producers are shown attached to or forming part of cach furnace,
yet that is not essential as such gas producers may constitute a separate
building, the gas being led therefrom to the furnace by suitable flues or
ducts as is at present practised with Siemen's gas furnace and producers.
Having now described and particularly ascertained the nature of my
said Invention, and the system, mode, or manner in or under which the
same is or may be used or practically carried into effect, I desire to
observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein-before
in part recited Letters Patent is, the arrangement or construction of
furnaces in which the whole space below the tank or receptacle is
divided to contain two sets of heat restoring flues or ducts, into which
the waste products of combustion pass in two portions from the central
or end portion of the furnace as herein-before described.
In witness whereof, I, the said James Sheffield, have hereunto
set my hand and seal, this Seventeenth day of February, One