IMPROVE- MENTS IN HEATING GLASS FURNACES
Year: 1862

page_text: LETTERS PATENT to John Henry Johnson, of .47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN HEATING GLASS FURNACES."-A communication from abroad by
Joseph Venini of Paris in the Empire of France Engineer
Sealed the 13th April 1863, and dated the 27th October 1862.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on the
27th October 1862.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN HEATING GLASS FURNACES," a communication from abroad
by Joseph Venini, of Paris, in the Empire of France, Engineer, to be as
follows:-
This Invention relates to an economical mode of heating glass furnaces of
all kinds, and consists in employing for that purpose the waste gases from coke
In carrying out this Invention the gas emitted from the coke ovens is
conveyed by suitable passages or flues into a fire-brick depositing chamber,
when any cinders or heavy matter carried over are deposited, the current of
the gas being here retarded by having a division wall extending downwards to
near the bottom of the chamber, under which partition the gas has to pass
before it can escape. A syphon pipe opens into one end of the depositing
chamber at the top thereof, and communicates with the upper part of a con-
denser. This condenser consists of a metal vessel having an expanding tube

page_text: fitted to the under side of the cover, and reaching down to near the bottom of
the vessel, the largest diameter of this tube being at the lower end, whilst its
smaller end opens direct into the second mouth of the syphon pipe. A rose
jet is contained inside the expanded tube, and is supplied with water from a
cistern above, so that as the gas passes from the depositing chamber it is
cooled by passing through the stream of cold water, and the tar being
condensed falls to the bottom of the vessel. From the upper part of this
vessel the gas freed from the tar passes through pipes to the glass furnace,
previous to which it is heated and mixed with a blast of air, and directed
through tuyeres into the chamber of the furnace containing the glass.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 27th April 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, John
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of October, in the year of
Lord One thousand eight hundred and sixty-two, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give, and grant unto me,
the said John Henry Johnson, Her special license that I, the said John Henry.
Johnson, my executors, administrators, and assigns, or such others as I, the said
John Henry Johnson, my executors, administrators, or 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 Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
HEATING GLASS FURNACES," a communication from abroad by Joseph Venini, of
Paris, in the Empire of France, Engineer, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or administrators,
by an instrument in writing under my hand and seal, or under the hand and
seal of one of them, 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.

page_text: NOW KNOW. YE, that I, the said John Henry Johnson, 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, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say:-
}
The said Invention relates to an economical mode of heating glass furnaces
of all kinds, and consists of an arrangement for employing for that purpose
the waste gases from coke ovens. In carrying out this Invention, the gas
emitted from the coke ovens is conveyed by suitable passages or flues into a
fire-brick depositing chamber, where any cinders or heavy matter carried over
are deposited, the current of the gas being here retarded by having a division
wall extending downwards to near the bottom of the chamber, under which.
partition the gas has to pass before it can escape. A syphon pipe opens into
one end of the depositing chamber at the top thereof, and communicates with
the upper part of a condenser. This condenser consists of a metal vessel
having an expanded tube fitted to the under side of the cam, and reaching
down to near the bottom of the vessel, the largest diameter of this tube being
at the lower end, whilst its smaller end opens direct into the second mouth of
the syphon pipe. A rose jet is contained inside the expanded tube, and is
supplied with water from a cistern above, so. that as the gas passes from the
depositing chamber it is cooled by passing through the stream of cold water,
and the tar being condensed falls to the bottom of the vessel. From the
upper part of this vessel the gas freed from the tar passes through pipes to
the glass furnace, previous to which it is heated and mixed with a blast of air,
and directed through tuyeres into the chamber of the furnace containing
the glass.
And in order that the said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed; the
same letters of reference indicating corresponding parts in all the Figures...
Figure 1 of the Drawings represents a longitudinal section of the combined
apparatus. for heating a glass furnace by the waste heat from coke ovens,
taken along the line 7, 8, in the plan; Figure 2 is a corresponding plan of the
same, partly in section; and Figure 3 is transverse section along the line 1-6,
in Figure 2.
a, a, are the series of coke ovens, and b, b, the doors through which the
overs are charged and emptied. They are composed of fire-clay, and con-
tained in cast-iron frames, counterweights enabling them to be readily raised
and lowered. The apertures c, c, are those through which the gas escapes in

page_text: the ordinary process of making coke. These apertures are in this case
surrounded with brick work, forming small chimnies, having at their summits
the same internal sections corresponding to those which are in the oven, and
in the wall, next the centre of the oven, other equal sections. It is through
these apertures or passages that the gases enter the principal flue e, in order
to be conveyed to the chambers f, f, herein-after referred to. The passages d
and e being situate immediately over the roof of the ovens preserve a
sufficiently elevated temperature to prevent the condensation of the gas tar,
nothing being deposited therein except the dust and cinders, which may be
carried along with the draught, but which can be readily removed. For this
purpose the chimnies as well as the passages leading therefrom, and the main
flue or passage are covered by slabs of fire-clay or cast iron, which are easily
removeable to admit of the thorough cleaning of the passages from the
commencement up to the point where they enter the chambers f. These
chambers of an elliptical form, slightly contracted on one side, are constructed
of bricks specially prepared of the curved form and thickness required. They
are braced together, or surrounded by a metal casing, in order to prevent any
change of form taking place by the action of the great heat to which they are
subjected during the working of the apparatus. The gases which enter
continually into these chambers from the main flues e, e, being at a highly
elevated temperature, preserve the tar in an aereform or gaseous state. The
cinders and other heavy bodies carried along with the gases are deposited on
the bottoms of these chambers, where the current of the gases is checked and
considerably reduced in its velocity by the presence of a diaphragm (shown in
dotted lines in Figures 1 and 2), which descends from the top to within a
short distance from the bottom of each depositing chamber, and under which
diaphragm the gases must pass before rising again to leave the chambers.
The deposited matter is removed through apertures provided with doors for
the purpose. These chambers fare covered on the top by a slab of semi-
refractory clay well burnt, and of a moderate thickness. In each of these
covers is formed an aperture g, to which is fitted a syphon tube h, com-
municating each with a condenser i. These condensers are constructed of
wrought-iron plates firmly secured together, and of a suitable thickness. The
top and bottom consist of plates of cast iron, the one forming the top or cover
being removable. These covers are each formed with an opening j, into which
is fitted the tapered tube k inside the condenser, which tube is of a gradually
increasing diameter towards the lower extremity, where it is encircled by a
band. The syphons h communicate at one extremity with the openings 9 in
the chambers f, and at the other end with the apertures j in the covers of the

page_text: condensers i, and with the upper ends of the tapered tubes k inside the con-
densers. At the bend of the syphon pipes there is fitted a small pipe l, which
descends into the tapered tube, and is fitted with a rose jet on its lower
extremity, whilst its upper end communicates with a tank or reservoir of
water. The gases having been freed from cinders and other solid particles in
the chambers f, pass by means of the syphon pipes h and tubes k into the con-
densers i, where they are subjected to the jets of water issuing from the rose
on the end of the pipe l. The tar is thus condensed, and falls on to the bottom
of the condenser, whence it is run off into suitable receptacles placed outside,
whilst the gases rising above the level of the water in the condenser pass off
through the apertures m in the covers of the condensers, as shown in Figure 2.
The pipes n communicate at one end with the apertures m in the covers of
the condensers, and at the other extremity with the lower portion of the
cylindrical vessels of sheet iron o. These vessels by resting upon the covers
of semi-refractory clay of the chambers f (the temperature of which is
maintained considerably elevated by the current of gases continually passing
through them from the coke ovens), receive a portion of their heat, and
transmit it consequently to the gas arriving from the condensers i. The
cylindrical vessels o are each divided into two compartments by a partition or
diaphragm of sheet metal o', which extends from the top downwards to
within a short distance from the bottom, as shown in Figure 3, and con-
sequently the gases are compelled to pass under the diaphragms, and in
contact with the bottom of the vessel. Openings are made in the lower
portion of the vessel o, through which any remaining deposited matter which
has passed through the condensers is withdrawn. On the upper part of these
vessels o are fitted the pipes p, through which the gas which has absorbed a
certain amount of caloric in the vessel o, and has consequently acquired a
certain velocity enters the pipes q, and then passes up the vertical pipes 1.
At the elbows or bends of the pipes 9 are fitted small pipes, which descend
into the vessel q' filled with water (Figure 3), and which serve to remove
from the pipes which convey the gas to the melting furnace any deposit of tar
or residuum of condensation which may form after the gas leaves the cylindrical
vessels o. The pipes are placed in two cylindrical chambers formed in the
brickwork of the furnace beneath the surface or hearth on which the crucibles
are placed, and into these chambers a jet of flame may, if desired, be
introduced. The gases on entering these pipes r attain a sufficiently elevated
temperature to be injected into the furnace. At one of the extremities of each
of the pipes ra tuyere is fitted, which is situate at the opening through which
the gases enter the furnace. At this point a current of air produced by any

page_text: suitable blowing engine and passed along a spiral pipe, and heated in the
apparatus s, s, placed above the furnace, enters by means of another small
tube into the head of each tuyere, which it fills up to the extremity, at which
point combustion should commence. The red arrows indicate the course of
the gas in the several pipes and passages, and the black arrows show the
.course of the air blast. When all is arranged for commencing the operations,
the coke ovens are to be kept burning for three or four days in the usual
manner, during which time the glass furnace is heated by means of a grate
adapted provisionally at the mouths where the gas is to enter. When, the
chambers are properly heated, and the gas tuyeres are substituted for the
temporary grate, the chimnies of those coke ovens which are in a position to
furnish combustible products are closed, a regular current of gas. being
established between the coke ovens and the glass furnace through the passages
d and e. Supposing this operation to have been carried out with regard to
four couples of coke ovens, the gases deduced therefrom arrive simultaneously
in the pipes r by the pipes p and q, to become there mixed with the blast of
air supplied by the blowing engine, and heated in the chambers s, s, thus pro-
ducing a flame which will raise the temperature of the glass furnace to the
desired degree. This occurs during the working of the first set of coke ovens
which are in a condition to supply the gas required; but these ovens when
the carbonization is advanced commence to give off inferior products of com-
bustion, which still continue to burn in the place where they are formed, by
reason of the entrance of a small supply of air through the charging and
discharging doors of the coke ovens. In the meantime another set of coke
ovens having been successively charged with coal attain the condition of those,
the products or gases of which have been first employed, and therefore before
opening the chimnies of these latter, and shutting off the communication with
the passages d and the other flues, a communication; is established with the
second set of ovens in the manner herein-before described in reference to the
first series, so that the same quantity of gas will always pass into the apparatus
and glass melting furnace, and there maintain in a constant manner the same
degree of heat. During the time the chimnies of the coke ovens remain open
the gases escape in combination with more or less steam or moist vapour
according to the degree of heat, and as it is requisite that the attendants
should be protected from the noxious influence of these emanations a hood M
of sheet iron is placed over each pair of ovens, which communicates by means
of a pipe with a chimney of a suitable height to carry, off the same above the
works. In order to prevent any stoppage of the works through the derange-
ment of the flues & and e, it is proposed to construct duplicates of these flues

page_text: to each series of ovens, so that one may be used should any accident occur to
the other.. These accidents are not liable to occur to the chambers f, which
are provided with small doors f', and with two other corresponding ones on
the opposite side. The whole of the pipes are made to take to pieces readily,
either for cleaning or for repairs, or for the substitution of other pipes of a
larger or smaller diameter, as there is no fastening employed for coupling
these pipes with the apparatus with which they are in communication. In
the same way the pipes which heat the gases, and which are contained in the
cavities formed for that purpose in the furnace may be changed, as by reason
of the great heat to which they are subjected these pipes are more liable to
deterioration. For this purpose the two pipes or retorts required for mixing
the air with the gas at the mouths of the furnace are brought over one of
these pipes whilst the other is being charged, and vice versa.
the gases from the two couples of coke ovens will alone heat the glass furnace,
but this circumstance will not cause the least inconvenience since care will
be taken to effect the charging during the period, when the materials having
been melted and refined require only a moderate degree of heat.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would 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,-
1st. The general system or mode of heating glass furnaces by means of
the gas obtained from coke ovens, substantially as herein-before described.
2nd. The general combination and arrangement of apparatus for heating
glass furnaces by means of the gas obtained from coke ovens, substantially as
herein-before described and illustrated by the Drawings.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Twenty-seventh day of April, One thousand
eight hundred and sixty-three.
J. HENRY JOHNSON. (L.s.)