IMPROVE- MENTS IN FURNACES FOR MELTING GLASS AND IN CRUCIBLES EMPLOYED THEREWITH
Year: 1882

page_text: LETTERS PATENT to William Bowers Fitch of New Cross Glass Works,
Deptford, in the county of Kent, Chemist for an Invention of "IMPROVE-
MENTS IN FURNACES FOR MELTING GLASS AND IN CRUCIBLES EMPLOYED
THEREWITH
او
PROVISIONAL SPECIFICATION left by the said William Bowers Fitch at
the Office of the Commissioners of Patents on the 30th December 1882.
WILLIAM BOWERS FITCH of New Cross Glass Works, Deptford, in the county
of Kent, Chemist "IMPROVEMENTS IN FURNACES FOR MELTING GLASS AND IN
CRUCIBLES EMPLOYED THEREWITH
"
This invention relates to improvements in furnaces for melting glass on the
continuous principle also to crucibles employed in glass melting.
In carrying out my invention I employ a perforated slab of suitable refractory
material placed over or near the top of the tank which is of ordinary construction.
In place of the ordinary "working out ring" I employ a number of tubes placed
at an angle and extending nearly to the bottom of the tank whereby I obtain a
uniform supply of metal from the bottom part of the tank at the same time
allowing the heat to be better contained within the furnace and protecting the
workmen from the effects of the flame and heat which is usually so objectionable
with furnaces as hitherto constructed.
Where the usual "working out ring" is employed I provide a stop for the same
so placed as to keep the ring in the required position; the bottom part of the
pedestals supporting the slab may be arranged to form such a stop, or the said
stop may be formed on the perforated slab, or projections may be formed on the
sides of the tank.
For feeding the furnace I provide suitable retorts placed so that their mouths
can discharge onto the herein before described perforated slab and the retorts be
heated by the furnace; the said retorts are provided with doors or slides; the
"collet is placed in the said retorts and as it becomes melted it is discharged
onto the herein before described perforated slab so that it will enter the tank in
a heated condition; when no supply is required the herein before described doors
دو

page_text: or slides are shut. Instead of the "collet" being melted in the retorts as herein-
before described it may be supplied from them onto the perforated slab and allowed
to remain there until sufficiently heated to flow into the tank.
Instead of employing a perforated slab I sometimes employ a plain slab placed
at an angle.
For strengthening the walls of the tanks of glass melting furnaces I introduce
a band or bands of asbestos paper, linen or other suitable tissue.
For strengthening the crucibles employed in glass melting I provide them with
bands of material such as asbestos paper either placed round the crucibles or
worked in with the clay from which the crucibles are moulded; or the crucibles
may be lined with such protecting material.
My improvements in glass furnaces further consist in providing the tanks
whether circular or otherwise with a number of tubes passing through the same
from the fire or fires whereby the metal is more quickly and uniformly melted and
the necessity of employing crucibles is avoided; or such tubes may be employed for
obtaining a bottom heat in such furnaces.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Bowers Fitch in the Great Seal Patent Office on the
30th June 1883.
WILLIAM BOWERS FITCH of New Cross, Glass Works, Deptford, in the county
of Kent, Chemist "IMPROVEMENTS IN FURNACES FOR MELTING GLASS AND IN
CRUCIBLES EMPLOYED THEREWITH
"
This invention relates to improvements in furnaces for melting glass on the
continuous principle also to crucibles employed in glass melting.
In carrying out my invention I employ a perforated slab of suitable refractory
material placed over or near the top of the tank which is of ordinary construction.
In place of the ordinary "working out ring" I employ a number of tubes placed
at an angle and extending nearly to the bottom of the tank whereby I obtain a
uniform supply of metal from the bottom part of the tank at the same time
allowing the heat to be better contained within the furnace and protecting the
workmen from the effects of the flame and heat which is usually so objectionable
with furnaces as hitherto constructed.
Where the usual "working out ring" is employed I provide a stop for the same
so placed as to keep the ring in the required position the pedestals supporting the
slab may be arranged to form such a stop, or the said stop may be formed on the
perforated slab, or projections may be formed on the sides of the tank.
For feeding the furnace I provide suitable retorts placed so that their mouths
can discharge onto the hereinbefore described perforated slab and the retorts are
heated by the furnace; the said retorts may be provided with doors or slides; the
"cullet" is placed in the said retorts and as it becomes melted it is discharged
onto the hereinbefore described perforated slab so that it will enter the tank in

page_text: "
a heated condition; when no supply is required the hereinbefore described doors
or slides are shut. Instead of the "cullet being melted in the retorts as herein-
before described it may be supplied from them onto the perforated slab and allowed
to remain there until sufficiently heated to flow into the tank.
Instead of employing a perforated slab I sometimes employ a plain slab placed at
an angle but I do not find this advantageous in practice.
For strengthening the walls of the tanks of glass melting furnaces I introduce
a band or bands of asbestos paper, linen or other suitable tissue.
For strengthening the crucibles employed in glass melting I provide them with
bands of material such as asbestos paper or rope either placed round the crucibles
or worked in with the clay from which the crucibles are moulded; or, the crucibles
may be lined with such protecting material.
My improvements in glass furnaces further consist in providing the tanks
whether circular or otherwise with a number of tubes passing through the same
from the fire or fires whereby the metal is more quickly and uniformly melted and
the necessity of employing crucibles is avoided; or such tubes may be employed
for obtaining a bottom heat in such furnaces.
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawing in which figure 1, is a
horizontal section and figure 2, a vertical section of a rectangular furnace for
melting glass provided with a perforated slab and retorts and a number of working
out tubes placed at an angle according to my invention; figures 3, and 4, are
similar views of the furnace shewing the arrangement of stops for keeping the
"working out ring" (when a ring is 'used) in the required position; figures 5,
and 6, are similar views of a circular furnace for melting glass in which a number
of tubes are employed passing from the fires to the flues through the tank for
melting the metal; figures 7, and 8, are similar views shewing a modification of
this arrangement in which the tubes are led from the centre of the furnace to the
flues. Similar letters in all the figures represent similar or corresponding parts.
In all the figures a, a, are the walls of the furnaces and b, b, are the fire boxes; c, c,
are the working out holes; d, the crown; e, the tank; f, the flues and k, k, the
filling in holes, all of ordinary construction.
"
I will first describe my improvements by reference to figures 1 and 2.
g, is the perforated slab of suitable refractory material placed as shewn over the
top of the tank e; h, h, are the tubes which I employ in place of the ordinary
'working out ring" placed as shewn and extending nearly to the bottom of the
tank c; i, i, are the pedestals for supporting the slab g,; j, j, are the retorts placed
in the fire boxes b, b, as shewn so that their mouths can discharge onto the slab g.
In this arrangement of furnace the "cullet" is placed in the retorts j, j, through
the filling in boles h, k, and as it becomes melted it is discharged onto the
perforated slab g, so that it will enter the tank e, in a heated condition. I some-
times provide the retorts j, j, with doors or slides which can be shut when no
supply of "cullet" to the furnace is required, the "cullet" will then become
heated in the retorts j, j, and be ready to be discharged direct into the furnace
when a supply is required; or the retorts may consist of a tube extending from one
filling in hole to the opposite one and downwardly curved towards the centre or
a seini-tube or gutter may be employed in a similar manner. Instead of the
'cullet" being melted in the retorts j, j, as herein before described it may be
supplied from them onto the slab g, and allowed to remain there until sufficiently
heated to flow into the tank. I have shewn the retorts of a semi-tubular horse
shoe form, which form I prefer to employ when the said retorts are placed (as
shewn in the drawing) in the fire boxes b, b, but I do not confine myself to this
form; I sometimes place one of the retorts in each of the filling in openings &, of
the furnace and construct them of a curved conical or horn shape and pivot them
to the filling in opening so that when the "cullet" becomes sufficiently melted and
plain it can be discharged directly into the tank by tilting the retorts. Or the
retorts may be dispensed with and the "cullet" fed direct onto the perforated slab.
"

page_text: The tubes h, h, allow of a uniform supply of metal being obtained from the
bottom part of the tank e; the heat is better contained within the furnace and the
workmen are protected from the effects of the flame and heat which are usually so
objectionable with furnaces as hitherto constructed.
For strengthening the walls of the tanks of the furnaces I introduce into the
refractory material for forming the same a band or bands or ropes of asbestos
paper, millboard, linen or other suitable tissue and by this means the expansion and
contraction of the walls are provided for.
For strengthening crucibles employed in glass melting furnaces I provide them
with bands of material such as asbestos paper or rope, either placed round the
crucibles or worked in with the clay from which the crucibles are moulded; or the
crucibles may be lined with such protecting material; or an interior jacket of
asbestos or the like may be introduced into the clay when the crucible is moulded;
by this means any defect in the clay of the crucible or the cracking of the same
will be provided for.
In the furnace shewn in figures 3, and 4, 1, 1, are the stops which I prefer to
employ for keeping the usual "working out ring" m, (when a ring is employed)
in the required position opposite the working out openings c, c, the said stops
consist of slabs of refractory material sliding vertically in grooves formed in the
sides of the tank e; they float in the liquid metal and rise and fall with the level
of the metal in the tank and thus also serve to keep the better quality of metal
opposite the working out openings c, c,; the pedestals i, i, (figure 2) may in some
cases form the stop for the "working out ring" or the stops may be formed on the
perforated slab g, or projections may be formed on the side of the tank e, for this
purpose.
In the furnace shewn in figures 5, and 6, n, n, are the tubes passing as shewn
from the fire boxes b, b, through the tank e, to the flues f; by this arrangement
the metal is more quickly and uniformly melted and the glass produced is of a
better quality. Instead of passing the tubes n, through the inside of the tank e,
I sometimes form the said tubes in the refractory material at the bottom of the
tank e.
In figures 7, and 8, which shew a modification of the last described arrangement,
the tubes n, are formed of a U shape and pass from the centre of the furnace near
the crown d, to the flues f, and the heat is thereby caused after traversing the
surface of the metal in the tank e, to return through the tubes n, to the flues f;
a large quantity of the heat which would otherwise be lost is thus imparted to the
metal. Instead of forming the tubes of a U shape as shewn in figures 7, and 8,
I sometimes form them straight and provide them at the ends which enter the
flues f, with a collar or other suitable means of allowing the free ends which float
on the surface of the metal to rise and fall with the level of the liquid metal, the
free ends of the tubes being slightly turned up to prevent the metal from entering
the tubes.
Having thus described my invention and the best means I am acquainted
with for carrying the same into effect I would have it understood that what I
claim is :-
Firstly. In a furnace for melting glass the construction and employment of a
perforated slab in combination (or not) with a retort for supplying the said slab
with metal substantially as and for the purposes hereinbefore described and
represented in figures 1, and 2, of the accompanying drawing.
Secondly. In a furnace for melting glass the construction and employment of
retorts for supplying the furnace with heated metal substantially as hereiubefore
described.
Thirdly. In a furnace for melting glass the employment of tubes extending to
near the bottom of the tank arranged substantially in the manner and for the
purposes hereinbefore described and represented in figures 1, and 2, of the accom-
panying drawing.
Fourthly. The method herein described of strengthening the walls of glass

page_text: "
melting furnaces and clay crucibles by the employment of asbestos in the manner
substantially as described.
Fifthly. In a furnace for melting glass the employment of stops for keeping the
working out ring" and the more refined metal in the required position substan-
tially as hereinbefore described and represented in figures 3, and 4, of the
accompanying drawing.
Sixthly. In a glass melting furnace the arrangement of tubes passing from the
fire boxes through the tank, or bottom of the tank, to the flues substantially as
and for the purposes herein before described and represented in figures 5, and 6, of
the accompanying drawing.
Seventhly. The modified arrangement in which the tubes pass from the centre of
the furnace to the Blues substantially as herein before described and represented in
figures 7, and 8, of the accompanying drawing,
Eighthly. The modified arrangement in which one end of each of the tubes is
fitted loosely in the mouth of the flue and the other end floats on the liquid metal
in the tank substantially as hereinbefore described.
Ninthly. The manufacture and use of the improved glass melting furnaces and
the improved crucibles employed in glass melting all constructed, arranged and
operating substantially as hereinbefore described and represented in the accom-
panying drawing.
In Witness whereof I the said William Bowers Fitch have hereto set my
hand and seal this thirtieth day of June in the year of our Lord one
thousand eight hundred and eighty three