IMPROVEMENTS IN FURNACES AND APPARATUS FOR MELTING, REFINING, AND WORKING OUT GLASS
Year: 1872

page_text: LETTERS PATENT to Charles William Siemens, of No. 3, Great George
Street, Westminster, in the County of Middlesex, for the Invention
of "IMPROVEMENTS IN FURNACES AND APPARATUS FOR MELTING, REFINING,
AND WORKING OUT GLASS."-Partly a communication from abroad by
PROVISIONAL SPECIFICATION left by the said Charles William Siemens
at the Office of the Commissioners of Patents, with his Petition,
on the 21st November 1872.
I, CHARLES WILLIAM SIEMENS, of No. 8, Great George Street, West-
minster, in the County of Middlesex, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN FURNACES AND APPARATUB FOR
MELTING, REFINING, AND WORKING OUT GLASS," to be as follows:-
In the melting and working-out of glass it is of importance that the
operation should be carried on in a continuous manner, crude materials
being supplied at the one end of the melting tank, and the refined glass
being worked out at the other end. The glass as it becomes melted

page_text: sinks towards the bottom of the tank where it is purest, the less pure and
imperfectly melted and incorporated portions floating above. It is
therefore advantageous to prevent the passage of these lighter matters
towards the working-out end of the tank, and, in working out the glass,
to draw it from a low level.
This Invention relates to the arrangement and construction of bridges
and working-out mouth pieces for glass melting tanks in such a manner
as to ensure the working out of only the most thoroughly melted and
purest portions of the material. For this purpose bars or girders of fire-
clay or other refractory material are floated on the surface of the molten
matter in the tank and placed therein transversely at intervals, so that
they form floating, bridges, dividing the upper stratum of the molten
matter into compartments. The imperfectly melted or unpure material
is thus kept at the supply end of the tank, and only the more thoroughly
melted and purer matter is permitted to flow towards the working-out
end by passing downwards and under these floating bridges..
The bridges may be secured at different parts of the tank in the
following manner:-Each of the bars or girders forming a bridge is made
with a hollow nearly semicircular or V shaped at each of its ends, and
corresponding hollows are formed at each side of the tank at the points
where it is desired that the bridges should be placed. When a bridge is
floated to this position presenting the hollows in its ends to face the
hollows in the sides of the tank, cylindrical, conical, or prismatic pieces of
fire-clay or other refractory material are let down from above through
apertures in the roof of the furnace into the spaces offered by these
hollows, and these pieces floating on the molten fluid serve as keys or
dowels which retain the bridge in its position.
In order that the glass to be worked may be drawn from a low level,
and in order to protect the workman from the flame of the furnace, a
mouth piece is provided which is of the form of a cowl or right angled
bend of a pipe of large diameter. One end of this bend or cowl dips
down some depth into the molten fluid, and the other end presents its
mouth to the operator outside, who, drawing the molten glass from the
interior of the bend or cowl, thus obtains a supply, not from the surface,
but from some depth down the melted fluid.
The floating bridges, with their keys or dowels, as well as the mouth
pieces above described, being made and placed separate from the struc-

page_text: ture of the tank itself, can be readily removed when worn out, and re-
placed by fresh ones. One or more of such bridges and mouth pieces
may be used, either separately, or in conjunction, in the same tank,
which by preference is worked on the principle of a regenerative gas
furnace, and may be generally of the form and construction described in
the Specification of a Patent granted to me dated 25th May 1870,
No. 1513; also, along with bridges or mouth pieces such as are
described above may be employed floating rings of refractory material to
assist the vertical circulation of the molten matter in the manner
described in a Provisional Specification filed by me on the 18th July
1872, No. 2152.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles William Siemens in the Great Seal Patent
Office on the 21st May 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
WILLIAM SIEMENS, of No. 8, Great George Street, Westminster, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of November, in the
year of our Lord One thousand eight hundred and seventy-two, in
the thirty-sixth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Charles William Siemens, Her
special license that I, the said Charles William Siemens, my executors,
administrators, and assigns, or such others as I, the said Charles William
Siemens, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Ohannel Islands, and Isle of Man, an Invention for
“IMPROVEMENTS IN FURNACES AND APPARATUS FOR MELTING, REFINING, AND
WORKING OUT GLASS," the result partly of a communication made to me
from abroad by Frederick Siemens, of Dresden, in the Kingdom of
Saxony, and partly of an Invention and discovery made by myself, upon
the condition (amongst others) that I, the said Charles William Siemens,
my executors or administrators, by an instrument in writing under my,

page_text: or their, or one of their hands and seals, should particularly 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 Charles William Siemens, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, reference being had to the
accompanying Sheet of Drawings, and to the figures and letters marked
thereon, that is to say :-
In the melting and working-out of glass it is of importance that the
operation should be carried on in a continuous manner, crude materials
being supplied at the one end of the melting tank, and the refined glass
being worked out at the other end. The glass as it becomes melted
sinks towards the bottom of the tank where it is purest, the less pure
and imperfectly melted and incorporated portions floating above. It is
therefore advantageous to prevent the passage of these lighter matters
towards the working out end of the tank, and in working out the glass
to draw it from a low level.
This Invention relates to the arrangement and construction of bridges
and working out mouth pieces for glass melting tanks in such a manner
as to ensure the working out of only the most thoroughly melted and
purest portions of the material. For this purpose bars or girders of fire-
clay or other refractory material are floated on the surface of the molten
matter in the tank, and placed therein transversely at intervals, so that
they form floating bridges, dividing the upper stratum of the molten
matter into compartments. The imperfectly melted or impure material
is thus kept at the supply end of the tank, and only the more thoroughly
melted and purer matter is permitted to flow towards the working out
end by passing downwards and under these floating bridges.
The bridges may be secured at different parts of the tank in the
· following manner :-Each of the bars or girders forming a bridge is made
with a hollow nearly semicircular or T shaped at each of its ends, and
corresponding hollows are formed at each side of the tank at the points
where it is desired that the bridges should be placed. When a bridge is
floated to this position, presenting the hollows in its
ends to face the

page_text: hollows in the sides of the tank, cylindrical, conical, or prismatic pieces
of fire-clay or other refractory material are let down from above through
apertures in the roof of the furnace into the spaces offered by these
hollows, and these pieces floating on the molten fluid serve as keys or
dowels which retain the bridge in its position.
In order that the glass to be worked may be drawn from a low level,
and in order to protect the workman from the flame of the furnace a
mouth piece is provided which is of the form of a cowl or right angled
bend of a pipe of large diameter. One end of this bend or cowl dips
down some depth into the molten fluid, and the other end presents its
mouth to the operator outside, who, drawing the molten glass from the
interior of the bend or cowl, thus obtains a supply, not from the surface,
but from some depth down the melted fluid.
The floating bridges, with their keys or dowels, as well as the mouth
pieces above described, being made and placed separate from the struc-
ture of the tank itself, can be readily removed when worn out, and
replaced by fresh ones. One or more of such bridges and mouth pieces
may be used, either separately, or in conjunction, in the same tank,
which by preference is worked on the principle of a regenerative gas
furnace, and may be generally of the form and construction described in
the Specification of a Patent granted to me dated 25th May 1870,
No. 1513; also along with bridges or mouth pieces such as are described
above may be employed floating rings of refractory material to assist
the vertical circulation of the molten matter, in the manner described in
a Provisional Specification filed by me on the 18th July 1872,
Figure 1 represents a longitudinal section; Fig. 2, a transverse section;
and Fig. 8, a sectional plan of a furnace for melting glass fitted according
to this Invention.
At the one end of the furnace are the doors A, A, for feeding the
materials to be fused in the tank B, and at the opposite end are the
working out doors, one of which is shewn at C. The sides and bottom
of the tank are kept cool by air flues b, b, which lead to the chimney,
the' draught of which causes a current of cool air to flow through them.
In an intermediate position between the feeding and working out ends of

page_text: -
the tank are placed bridges of refractory material D, D, which may be
rectangular or other shaped bars of fire-brick, or, as is shewn in the
Drawings, they may be round and tubular, such as will float partly
submerged in the fused contents of the tank. In order to keep them
from shifting their ends are hollowed out vertically, and corresponding
hollows are provided in the sides of the tank or in projecting parts of
those sides, and dowels or keys of fire-brick E, E, are let down into these
hollows through openings e, e, in the roof of the furnace, which are
closed after their introduction. The dowels or keys E, E, are most con-
veniently made of round form, as shewn in the Drawings, as pieces of
that form fit in any position, and they are a little tapered at their lower
ends to render their insertion easy. These dowels, however, might be
rectangular, polygonal, or of other form in section, as may be readily
understood, the hollows into which they are inserted being made of
corresponding form; in all cases they should fit somewhat loosely, so that
the bridges D, D, which they steady in position may nevertheless be free
to rise or descend according as the level of the fused material in the
tank may vary. From this arrangement it will be seen that the more
crude and less perfectly fused and compounded materials at the feeding
end of the tank which float are prevented from entering that part of the
tank where the glass is worked out.
In order to effect a more thorough compounding of the materials, a
number of fire-brick rings or short pieces of cylinders F, F, may be
floated on the fused material at the working out end.
These rings
promote a certain amount of vertical circulation of the liquid, and render
its composition more uniform, and the glass may be worked out through
them.
Fig. 4 represents a transverse section of the working out part of a
glass furnace with mouth pieces or hoods applied to it according to this
Invention. These hoods G, G, serve to protect the workman from the
flame of the furnace, and at the same time being made to dip down some
distance into the liquid, they secure the removal of material for working
only from the lowest portion of the tank where it is most pure and most
thoroughly compounded and fused.
Any number of the bridges D, D, may be placed in a glass furnace,
and may be employed with the rings F, F, and hoods G, G, or without
them, and the rings F, F, may be used alone, as also the hoods G, G, or

page_text: sets of either or both may be used along with sets of the other or with
bridges, as may be readily understood.
Having thus described the nature of this Invention, and manner
in which the same is to be performed, I claim,—
First. The use in tank glass furnaces of floating bridges, substantially
in the manner and for the purposes herein described.
Second. The use in tank glass furnaces of floating rings in combination
with floating bridges, substantially in the manner and for the purposes
herein described.
Third. The use in tank glass furnaces of working out hoods, sub-
stantially as herein described.
In witness whereof, I, the said Charles William Siemens, have
hereunto set my hand and seal, this Nineteenth day of May, in
the year of our Lord One thousand eight hundred and seventy-
three.
0
Witness,
JNO. A. HEAD,
8, Gt. George St.,
Westminster,
S.W.
C. WILLIAM SIEMENS. (L.S.)