IMPROVEMENTS IN FUR- NACES FOR THE REDUCTION AND CALCINATION OF LEAD, TIN, AND COPPER ORES
Year: 1858

page_text: LETTERS PATENT to Alfred Jenkin, of Carrick Mines, in the County of
Dublin, Mining Engineer, for the Invention of "IMPROVEMENTS IN FUR-
NACES FOR THE REDUCTION AND CALCINATION OF LEAD, TIN, AND COPPER ORES.
NACES FOR THE REDUCTION AND CALCINATION OF LEAD, TIN, AND COPPER ORES.
Sealed the 25th June 1858, and dated the 23rd April 1858.
PROVISIONAL SPECIFICATION left by the said Alfred Jenkin at the
Office of the Commissioners of Patents, with his Petition, on the
23rd April 1858.
I, ALFRED JENKIN, of Carrick Mines, in the County of Dublin, Mining
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN FURNACES FOR THE REDUCTION AND CALCINATION OF LEAD, TIN, AND
COPPER ORES," to be as follows:-
This Invention relates to certain improvements upon and modifications of
the double reverberatory furnaces employed in the reduction and calcination
of lead and copper ores, for which British Letters Patent were granted to me
on or about the Twenty-third day of April, One thousand eight hundred and
fifty-five, by which improvements and modifications I am enabled greatly to
expedite the processes of calcination and reduction with a less consumption of
fuel, and to condense the vapours of oxide of lead generated in the flowing
furnace in a simple and economic manner.
According to my present improvements and modifications I substitute a

page_text: cast-iron bottom for the ordinary fire-brick bottom of the calcining furnace,
and in place of wasting a portion of the heat derived from the flowing furnace,
by directing it along a flue underground immediately on its leaving the flowing
furnace, I cause such heat to pass directly beneath and in immediate contact
with the cast-iron bottom of the calcining furnace, by which arrangement a
considerable quantity of the less refractory ore in the calcining furnace will
be reduced therein without requiring to be removed to the flowing furnace.
The main flue and the passages communicating between the flowing and
calcining furnaces are so modified in their form and arrangement, that three
dampers only are required in place of four, as in my former Patent above
referred to. The two passages leading from the flowing furnace into the
calcining furnace are totally distinct and separate from the main flue or
passage which is situated between them, so that there are in all three passages
opening into the end of the flowing furnace, each of which is furnished with
a separate damper. In order to economise the fuel as much as possible, I
lower the roofs of the two furnaces considerably, and curve the roofs down-
wards towards their centres, so as to bring the flames into close contact with
the ores.
For the purpose of condensing in an economical manner the vapours of
oxide of lead, which are thrown off in large quantities from the flowing
furnace, and are frequently wasted by passing up the chimney, I propose to
employ a cistern containing water, which is placed immediately beneath the
cast-iron bottom of the calcining furnace. The heat and vapours from the
flowing furnace are made to pass directly over the water in the cistern,
the steam from which effects the required condensation of the oxide. A
main flue constructed at the end of the calcining furnace receives the heat
and products of combustion from such furnace and from the main flue leading
from the flowing furnace, whence they pass off direct to the chimney.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Jenkin in the Great Seal Patent Office on the g
20th October 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Alfred
JENKIN, of Carrick Mines, in the County of Dublin, Mining Engineer, send
"greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of April, in the year of our Lord

page_text: One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Alfred Jenkin, Her special license that I, the said Alfred Jenkin, my
executors, administrators, and assigns, or such others as I, the said Alfred
Jenkin, 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 FUR-
NACES FOR THE REDUCTION AND CALCINATION OF LEAD, TIN, AND COPPER ORES,"
upon the condition (amongst others) that I, the said Alfred Jenkin, by an
instrument in writing under my hand and seal, 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 Alfred Jenkin, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, 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:-
My said Invention relates to certain improvements upon and modifications
of the double reverberatory furnaces employed in the reduction and calcination
of lead and copper ores, for which British Letters Patent were granted to me
on or about the Twenty-third day of April, One thousand eight hundred and
fifty-five, by which improvements and modifications I am enabled greatly to
expedite the processes of calcination and reduction with a less consumption of
fuel, and to condense the vapours of oxide of lead generated in the flowing
furnace in a simple and economic manner.
According to my present improvements and modifications I substitute a
cast-iron bottom for the ordinary fire-brick bottom of the calcining furnace,
and in place of wasting a portion of the heat derived from the flowing furnace,
by directing it along a flue underground immediately on its leaving the flowing
furnace, I cause such heat to pass directly beneath and in immediate contact
with the cast-iron bottom of the calcining furnace, by which arrangement a
considerable quantity of the less refractory ore in the calcining furnace will be
reduced therein without requiring to be removed to the flowing furnace. The
main flue and the passages communicating between the flowing and calcining
furnaces are so modified in their form and arrangement that three dampers

page_text: only are required in place of four, as in my former arrangement above referred
to. The two passages leading from the flowing furnace into the calcining
furnace are totally distinct and separate from the main flue or passage which
is situate between them, so that there are in all three passages, two opening
into the end of the flowing furnace, each of which is furnished with a separate
damper. In order to economise the fuel as much as possible, I lower the
roofs of the two furnaces considerably, and curve the roofs downwards towards
their centres, so as to bring the flames into close contact with the ores.
For the purpose of condensing in an economical manner the vapours of
oxide of lead, which are thrown off in large quantities from the flowing
furnace, and are frequently wasted by passing up the chimney, I propose to
employ a cistern containing water, which is placed immediately beneath the
cast-iron bottom of the calcining fuanace. A portion of the heat and vapours
from the flowing furnace are made to pass directly over the water in the
cistern, the steam from which effects the required condensation of the oxide.
A main flue constructed at the end of the calcining furnace receives the
heat and products of combustion from such furnace and from the main
flue leading from the flowing furnace, whence they pass off direct to the
chimney.
And in order that my 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 Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts in both Figures.
Figure 1 of the annexed Sheet of Drawings represents a longitudinal
vertical section of my improved combined calcining and reducing furnace for
lead, tin, and copper ores, and Figure 2 is a corresponding plan of the same.
A is the ordinary fire-place, the heat and flame from which pass through the
lateral opening or passage B into the flowing furnace C, and after traversing
over the surface of the ore contained therein, enter by the two passages D, D..
direct into the calcining furnace E, which is on the same level with the flowing
furnace; F, F, are the passages which communicate with the main flue G
leading to the chimney; H is the main flue or passage leading from the
flowing furnace beneath the bottom I of the calcining furnace, and thence to
the flue G leading to the chimney. The several passages D, D, F, F, and H,
are each provided with a separate damper, worked by levers outside the
furnace in any convenient manner. The centre or middle damper at H
should be double the size of the two side dampers at D, D, and during the
processes of charging, turning, cooling, &c., the centre damper is opened and
the lateral ones closed, as also the dampers at F, F. By this means the

page_text: flowing furnace always continues in active operation; but so soon as the fire
is required in the calcining furnace the dampers at D, D, and F, F, are
opened, and the centre one at H closed. The bottom of the calcining fur-
nace is composed of a metal plate I, of cast iron, and a portion of the heat
and flame from the flowing furnace is allowed to play upon the under surface
of such plate, thereby greatly raising the temperature of the bottom of the
calcining furnace, and reducing a considerable quantity of the less refractory
ore contained therein. K is a water tank placed beneath the bottom of the
calcining furnace, whereby the vapours of oxide of lead from the flowing
furnace, by passing through the steam arising from the water which becomes
heated, are economically condensed, and collected in the tank. A suitable
aperture is made in the lower portion of the calcining furnace, to enable the
tank to be introduced and removed with facility. The lowering of the fur-
nace roofs, whereby a considerable economy of fuel is obtained, and the flames
brought into clear contact with the ore, is clearly indicated in Figure 1, the
crown of each furnace assuming the form of an inverted arch in longitudinal
section.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as variations may be made therefrom without deviating
from the principles or main features of my said Invention; but what I con-
sider to be novel and original, and therefore claim as the Invention secured to
me, by the herein-before in part recited Letters Patent is,―
First, the general construction, arrangement, and combination of parts of
furnaces for effecting the reduction and calcination of lead, tin, and copper
ores, as herein-before described and illustrated in my Drawings.
Second, the application and use to and in calcining furnaces of cast-iron or
other metal bottoms heated by the waste heat of an adjoining flowing furnace
or furnaces, in the manner and for the purpose herein-before described.
Third, the peculiar arrangement of flues or passages leading from the flowing
furnace to the calcining furnace, and to the main flue or chimney, as herein-
before described.
Fourth, the lowering of the centre portions of the roofs of the calcining
and flowing furnaces for the purpose of economising fuel, as berein-before
described.
Fifth, the system or mode of condensing the vapours of oxide of lead
evolved from the flowing furnace by causing such vapours to pass over and in

page_text: immediate contact with a cistern or tank of water before reaching the chimney,
as herein-before described.
In witness whereof, I, the said Alfred Jenkin, have hereunto set my
hand and seal, this Fifteenth day of October, One thousand eight hun-
dred and fifty-eight.
ALFRED JENKIN. (L.S.)