IMPROVEMENTS IN GLASS FURNACES
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Hugh Percival at the Office
of the Commissioners of Patents, with his Petition, on the 20th
October 1869.
I, HUGH PERCIVAL, of Sunderland, in the County of Durham, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
GLASS FURNACES," to be as follows:-
My Invention relates to an improved construction or arrangement of
glass furnace, by which the outwork journey or process of smelting the
raw materials from which the glass is made may be carried on
simultaneously with the inwork journey or manufacture of the same
into the articles required, whereby the said operations may be carried on
continuously and consequently with a great saving of time and fuel.
Moveover in the case of bottle making the necessity for skimming the
metal is obviated, thereby effecting economy in time and in the material
itself. The furnace, which is arched over as usual, I divide into two
distinct compartments, the one to be used exclusively for "outwork," or
smelting purposes, and the other for "inwork" purposes, or the manu-
facture of the "metal" into sheet, plate, crown, flint, or other glass,
bottles, or other articles. The wall separating the furnace into two

page_text: compartments reaches from the floor to the crown of the arch, and each
is further subdivided into compartments forming tanks or cisterns.
Pots or crucibles may be employed in lieu of the tanks if desired.
The outwork compartment comprises two smaller compartments or
cisterns, the one for receiving the raw material to be smelted by means
of à furnace, also contained within the outwork compartment, the other
for refining the molten glass or "metal" as it passes in from the founding
or smelting cistern or compartment. The smelting compartment is
separated from the furnace grate by a sill or bridge forming one of the
walls of said tank or compartment, over which bridge the flame from the
fire passes to impart a uniform heat to the smelting and refining com-
partments. These compartments are separated by a partition wall of
about the same height as the bridge, a conduit being provided for the
passage of the molten glass from the one to the other. Working holes
are formed in the sides of the furnace in the usual manner opposite the
smelting and refining tanks for the introduction therein of the materials
for forming and refining the glass; the usual air cave is also provided.
The inwork compartment is subdivided into three tanks or com-
partments by division walls similar to that separating the smelting and
refining compartments before described, and when so divided will in
addition to the ordinary means of heating such inwork compartment
be provided with a furnace underneath or adjacent to the tanks, or
cisterns. The flame from this furnace passes over a bridge separating it
from the middle or settling compartment or tank, and thus imparts a
uniform heat to the tanks for the purpose of keeping the "metal" con-
tained therein in a workable condition. Communication is established
between the refining compartment of the "outwork" furnace and the
settling compartment of the inwork furnace by means of a conduit or
passage formed in the partition wall before described as separating the
in work and outwork furnaces below the level of the floor of the said
refining and settling compartments. Communication is similarly
effected between the settling compartment and the two other tanks, or
"working" compartments of the inwork furnace and the usual working
holes are formed in the sides of the furnace by which access may be had
to the melted "metal" contained in the said working compartments.
The operation of the furnace is as follows:-The founding compart-
ment of the outwork furnace is charged with the materials to form
the glass, which when fused pass through the conduit before referred

page_text: to into the refining compartment, where cullet or broken glass may
be added through the working hole provided for the purpose, the
molten metal in both compartments or tanks being maintained at a
uniform temperature, as before described. The metal then passes into
the settling compartment of the inwork furnace, and as the passage con-
necting the same with the refining compartment is at or beneath the level
of the floor and consequently below the level of the metal, the passage
from one compartment to the other of the scum floating on the surface.
thereof is prevented, thus obviating the necessity for removing the same,
previous to working the glass. The metal remains in the settling com-
partment until all "boil" has subsided, whence it passes into the working
compartments through similar passages or conduits, and is removed
through the holes for manufacture in the usual manner.
The several compartments of the inwork and outwork furnaces being
placed in communication as above described, form together one large
tank, the floor of which is on the same level, the metal will therefore
rise to the same level in all the compartments, and the materials being
constantly supplied to the founding compartment as the metal is with-
drawn and manufactured at the working holes, a continuous flow of
metal will be established through the several compartments as before
described; the working compartments are thus kept constantly filled
with fine "metal" avoiding the inconvenience and disadvantages arising
from the working out or emptying of the tanks or pots.