IMPROVE. MENTS IN FURNACES, RETORTS, AND APPARATUS FOR SMELTING OR TREATING ZINC AND OTHER ORES
Year: 1866

page_text: LETTERS PATENT to Alfred Borgnet, of Swansea, in the County of
Glamorgan, South Wales, Manufacturer, for the Invention of "IMPROVE.
MENTS IN FURNACES, RETORTS, AND APPARATUS FOR SMELTING OR TREATING
ZINC AND OTHER ORES."
Sealed the 26th June 1866, and dated the 25th April 1866.
PROVISIONAL SPECIFICATION left by the said Alfred Borgnet at the
Office of the Commissioners of Patents, with his Petition, on the
25th April 1866.
I, ALFRED BORGNET, of Swansea, in the County of Glamorgan, South
Wales, Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN FURNACES, RETORTS, AND APPARATUS FOR SMELTING OR TREATING
ZINC AND OTHER ORES," to be as follows:-
My Invention of improvements in furnaces, retorts, and apparatus for
smelting or treating zinc and other ores consists in employing two or more
fire-grates to each furnace, and of employing retort protectors and heat regu-
lators provided with passages through which cooling air, vapour, or liquid
passes or circulates, so that by placing these protectors between the fire-grates
and the lowest tier or row of retorts in the furnace they will be protected from
excessive heat.
The Invention consists also in employing distilling retorts of a peculiar
form and proportions of parts, together with a novel form and arrangement of
parts in condensing tubes conjoined with the said distilling retorts; and,
further, in employing tubes for the circulation or passage of cooling air, vapour,
CD Sl

page_text: or liquid placed on the outside of large retorts or muffles, and in such a position
upon them as to be wholly or in part between the furnace fire or the current
of heat directed against the retorts or muffles. The employment of the pro-
tectors and heat regulators, as described, materially assists in preserving the
distilling retorts from the destructive action of the heat and in diffusing it
throughout the furnace.
I prefer to make the condensing tubes the outer one of sheet iron and the
inner ones of fire-clay.
The improvement in the fire-clay tube consists in partly closing its end
ndjoining the distilling retort, by which the liquid metal is prevented from
running back into the distilling retort. The upper part of the same end of
the tube is formed of an angular shape, by which the condensation of the zinc
vapour passing from the distilling retort is greatly facilitated.
The improvement in the outer condensing sheet-iron tube consists in cm-
ploying a low partition or ledge formed across it on its lower side within, so
as to be near the end of the former last-mentioned tube when in position; by
this partition or ledge the condensed metal and oxide are kept separate within
the tube.
My improvements in the distilling retorts consists in making them of an
oval form in section, and making them thinner at the upper part than at the
under, so that without increasing the weight I can obtain the strength required,
and the more equal action of heat upon the ore being distilled within it will
be also obtained. In the thicker under part of the retort hollow or tubular
spaces are made, which while lightening will also strengthen the retort and
will allow of the admission of air into the spaces.
My improvements in the retort protectors and heat regulators consist in
causing cooling currents of air, vapour, or liquid to pass or circulate through
them in pipes or tubes, or channels. The circulating or passing of air direct
from the atmosphere into and through the protectors and tubes will in some
cases be occasioned sufficiently by the rarefaction of the air in the said pro-
tectors and tubes, which will produce a natural draught, and this is facilitated by
placing one end higher than the other of each protector or tube in the furnace.
In other cases it is desirable to force or draw the cooling air, vapour, or liquid
through the protectors or tubes by any convenient mechanical means ordinarily
used for such a purpose. The rapidity of the passing of such cooling air,
vapour, or liquid should generally be regulated by the workman attending the
furnace according to the amount of heat he may require. The retort pro-
tectors and heat regulators are by preference composed of a series of fire-clay
tubes open at both ends and placed within a larger one having a similar

page_text: transverse section to the distilling retorts; or a series of fire-clay tubes placed
near together without exterior envelope may be employed.
In adapting the improved protectors and heat regulators to the ordinary
Silesian zinc retorts or muffles, an open fire-clay pipe or tube, or channel is
placed from the front thereof along the top and down the back end, where it
forms a chamber, and thence by branches along the sides returning to the
front. The hole in the back of the Belgian furnace protector is completely
closed, and a small clay tube or pipe is placed within it and reaches nearly to
the closed end; the pipe or tube thus conducts a cooling current of air,
vapour or liquid into it, and this air can then pass away at the front end
thereof.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Borgnet in the Great Seal Patent Office on the
25th October 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
BORGNET, of Swansea, in the County of Glamorgan, South Wales, Manu-
facturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fifth day of April, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Alfred Borgnet, Her special licence that I, the said Alfred
Borgnet, my executors, administrators, and assigns, or such others as I.
the said Alfred Borgnet, 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 Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN FURNACES, RETORTS, AND APPARATUS FOR SMELTING OR TREATING
ZINC AND OTHER ORES," upon the condition (amongst others) that I, the
said Alfred Borgnet, my executors or administrators, by an instrument in
writing under my, 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.

page_text: NOW KNOW YE, that I, the said Alfred Borgnet, 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 state-
ment, reference being had to the Drawing hereunto annexed, and to the letters
and figures marked thereon (that is to say):-
My Invention of "Improvements in Furnaces, Retorts, and Apparatus for
Smelting or Treating Zinc and other Ores" consists, first, in adapting two or
more fire-grates to each furnace, and in employing retort protectors and heat
regulators provided with passages through which cooling air, vapor, or liquid
passes or circulates, so that by placing these protectors between the fire-grates
and the lowest tier or row of retorts in the furnace the retorts will be protected
from excessive heat.
The Invention consists also in employing distilling retorts of peculiar form
and proportions of parts, together with a novel form and arrangement of parts
in condensing tubes or vessels in combination with the said distilling retorts;
and, further, in employing tubes for the circulation or passage of cooling air,
vapor, or liquid placed on the outside of large retorts or muffles, and in such
a position as to be wholly or in part between the retorts or muffles and the
furnace fire or the current of heat directed against the said retorts or muffles.
The employment of the protectors and heat regulators, as herein described,
will materially assist in preserving the distilling retorts from the destructive
action of the heat, and in diffusing the heat throughout the furnace in a more
uniform manner than heretofore.
The condensing apparatus consists of two tubes or vessels, the outer one of
which I prefer to make of sheet iron, and the inner one of fire-clay.
The improvement in the fire-clay tube or vessel of the condensing apparatus
consists in partly closing its end nearest the distilling retort, so that the liquid
metal will be thereby prevented from running back from the condenser into
the distilling retort. The upper part of the same end of the tube is formed
of an angular shape, by which the condensation of the zinc vapor passing from
the distilling retort will be greatly facilitated.
The improvement in the outer condensing tube, which is made of sheet iron,
consists in adapting to the inside a low partition or ledge formed across its
lower side and near the end of the fire-clay tube, when in position; by means
of this partition or ledge the condensed metal and oxide are kept separate
within the tube.
11
My improvements in the distilling retorts consist in making them of an
oval form in section, and making them thinner at the upper part than at the
under, so that without increasing the weight I can obtain the strength required.

page_text: and the more equal action of heat upon the ore being distilled within it will
be also obtained. In the thicker under part of the retort hollow or tubular
spaces are inade, which while lightening will also strengthen the retort, and
will allow of the admission of air into the spaces.
My improvements in the retort protectors and heat regulators consist in
causing cooling currents of air, vapor, or liquid to pass or circulate through them
in pipes or tubes or channels. The circulating or passing of air direct from
the atmosphere into and through the protectors and tubes will in some cases
be occasioned sufficiently by the rarefaction of the air in the said protectors
and tubes and will produce a natural draught, which is facilitated by placing.
one end higher than the other of each protector or tube in the furnace. In
other cases it is desirable to force or draw the cooling air, vapor, or liquid
through the protectors or tubes, by any convenient mechanical means ordinarily
used for such a purpose. The rapidity of the passing of such cooling air,
vapor, or liquid should generally be regulated by the workman attending the
furnace according to the amount of heat he may require.
In the accompanying Drawings I have shewn my Invention applied to a
zinc ore furnace. By means of my improvements I am enabled to obtain and
combine the chief advantages of the Silesian and Belgian systems of zinc
furnaces, so as to effect a great economy of labor in working the new system,
and also an increased production from the furnaces.
Fig. 1, Sheet I., represents a sectional elevation of a zinc furnace con-
structed upon the improved plan, the part shown in section being taken in
the line A, B, and A, B', of the Figure in Sheet III., which is a sectional plan
of the furnace.
The Figure in Sheet II. is a transverse section taken in the line C, D, of
Fig. 1 (Sheet I.); and Fig. 4, Sheet II., is a back elevation of the furnace.
Figures 1, 2, 3, and 4*, Sheet IV., represent various views of some of
the parts detached and drawn on an enlarged scale. Fig. 1 is a longitudinal
section of one of the improved retorts and of the ironwork connected there-
with at the front side of the furnace; Fig. 2* is a sectional plan of the same;
Fig. 3 is a sectional elevation taken at the line E, F, of Fig. 1°; Fig. 4° is
another sectional elevation taken at the line G, H, of Fig. 1; Fig. 5 repre-
sents one of the inner clay tubes or condensers, and shews the peculiar form
of the same.
. Fig. 6, Sheet V., is a longitudinal vertical section of one of the retort
protectors and heat regulators for shielding or protecting the retorts from the
direct action of the fire, and for assisting in distributing the heat throughout
the furnace. These retort protectors and heat regulators are, by preference,

page_text: composed of a series of fire-clay tubes open at both ends and placed within a
larger one having a similar transverse section to the distilling retorts; or a
series of fire-clay tubes placed near together without exterior envelope may be
employed, as shewn in the detached sectional views Figs. 6, in which a, a,
are the tubular retort protectors or regulators; b, b, Fig. 6, is a cast-iron pipe
for a cooling current of air, vapor, or liquid to pass through and issue from the
blast pipes c, c, c, as seen best in Figures 8 and 8°, Sheet V., which represent
this part of a Belgian furnace in elevation and in section.
In adapting the improved protectors and heat regulators to the ordinary
Silesian zinc retorts or muffles, as shown in Figures 7 and 7*, Sheet V., an
open fire-clay pipe, tube. or, channel o is placed from the front thereof along
the top and down the back and where it forms a chamber p, and thence by
branches the cooling current passes along the sides and returns to the front,
as shewn in the sectional view Fig. 7. The hole in the back of the pro-
tectors in the Belgian furnace, shown at Figures 8 and 8*, is completely
closed, and a small clay tube or pipe is placed within it and reaches nearly
to the closed end; the pipe or tube thus conducts a cooling current of air,
vapor, or liquid into the protector k, and this air can then pass away at the
front end thereof down the discharging pipe m. An attentive examination of
the Drawing, and a comparison of the two systems of furnaces shewn at
Figures 7, 7, and Figures 8, 8*, together with the explanatory references to
the Figures, will indicate the manner of adapting the Invention to the two
systems.
il
In Figures 1 and 2, g, g, are the distilling retorts from whence the
metallic vapors pass to the condensers f, f, which are clay vessels of peculiar
form, as already mentioned, and are shewn detached at Fig. 5. e, e, are sheet-
iron tubes or vessels to catch the oxides as they pass from the condenser f;
these vessels are provided with a transverse vertical partition e¹, Fig. 1, for
keeping the metal and the oxide separate. The peculiar form and construc-
tion of the distilling retorts, which forms an important feature of the Invention,
will be best understood by referring to the end views, Figures 3 and 4*,
Sheet IV. It will be seen that they are of an oval form in section, and that
the upper part is thinner than the lower, in which a number of air channels
are made. These air channels will lighten and at the same time strengthen
the retorts, and also keep them at a more equable temperature throughout.
Figures 1, 2, and 3, Sheet VI., represent the furnace complete in front eleva-
tion, sectional plan view, and transverse vertical section.
Having now described my Invention of "Improvements in Furnaces,
Retorts, and Apparatus for Smelting or Treating Zinc and other Ores," and

page_text: having explained the manner of carrying the same into effect, I claim as the
Invention secured to me by Letters Patent as aforesaid, the general construc-
tion and arrangement of parts herein set forth, whereby a considerable economy
in the distillation of zinc and other ores is effected.
I also claim the use of the retort protectors and heat regulators provided
with passages or channels for the passage of cooling air, vapor, or liquids, as
herein set forth.
I further claim the manner of constructing the distilling retorts as shewn
and described, and also the use and application of the peculiar construction of
condensing tubes or vessels.
Lastly, I claim causing air, vapor, or liquid to circulate in tubes placed on
the outside of large retorts or muffles, so as to be wholly or partly between the
furnace fire or flame and the muffles or retorts, as herein set forth.
In witness whereof, I, the said Alfred Borgnet, have hereunto set my
hand and seal, the Twentieth day of October, in the year of our Lord
One thousand eight hundred and sixty-six.
ALFRED BORGNET. (L.S.)