IMPROVEMENTS IN APPARATUS FOR COLLECTING THE WASTE FUMES OF FURNACES USED FOR SMELTING LEAD ORES
Year: 1879

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake, &
Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR COLLECTING THE WASTE FUMES OF
FURNACES USED FOR SMELTING LEAD ORES." A communication from abroad
by George T. Lewis, of Philadelphia, Pennsylvania, United States of America.
Sealed the 25th April 1879, and dated the 20th February 1879.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 20th February 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN APPARATUS FOR COLLECTING
THE WASTE FUMES OF FURNACES USED FOR SMELTING LEAD ORES." [A com-
munication from abroad by George T. Lewis, of Philadelphia, Pennsylvania, United
States of America.]
This Invention relates to apparatus for collecting waste fumes which incidentally
and necessarily escape from furnaces used for smelting lead ores.
In the process of smelting lead-ores large amounts of volatile fumes necessarily
escape and are lost. Moreover these escaping fumes are found to be injurious to
the surrounding land. Various attempts have been heretofore inade by passing
these escaping fumes through horizontal or ascending flues of great length to cause
the said fumes to be deposited, but these attempts have been attended with great
expense and have been only partially successful.
By passing the escaping fumes from a lead ore smelting furnace through a series
of cooling tubes and then into a series of bags the said escaping fumes can be
thoroughly and effectually strained out and collected, while the attachment of the
cooling tubes and collecting bags does not interfere with the smelting operations.
A cooling and collecting apparatus constructed according to this Invention may
be used in combination with either of the ordinary lead ore smelting or reducing
furnaces, such as the Scotch eye furnace, the reverberatory smelting furnace, or the
cupola smelting furnace, or with the lead refining furnace.
In carrying the said Invention into practice I provide a descending flue which
leads from the chimney or shaft of the furnace to a series of vertical cooling tubes,
so arranged that the fumes are forced to ascend and descend successively as they

page_text: pass along through the said tubes. These tubes are made of sheet metal, as thin
metal rapidly throws off the heat of the contents and cools the fumes. The said
tubes should be about two feet in diameter, and the series should furnish about
three hundred and fifty feet of aggregate length. They can be cleaned out by
oponings with moveable covers made in the lower part of the flue if necessary, but
the deposit will be very small. The last tube of the series of tubes communicates
with the eye of a fan, and the fumes are drawn by this fan through the said series
of cooling tubes and discharged into a tube which connects with a horizontal tube.
From the latter are suspended a series of strainers or bags composed of textile
fabric, through the meshes of which the gases escape leaving the solid material or
fume proper within the bag or strainer. Instead of textile fabric any similar
straining material may be used.
The said fumes so collected are composed of sulphate, sulphite, carbonate, and
oxide of lead when ordinary galena ore is smelted; when carbonate lead ores are
smelted the fumes collected will be found to consist of oxide and carbonate of lead
mainly. If the ores smelted are the argentiferous ores of lead then the fumes so
collected will contain in addition to the above mentioned salts of lead also the
corresponding salts of silver. The fumes when collected in the said bags are
removed therefrom by shaking, and may be either used as a grey pigment direct, or
after purification as a whiter pigment, or they may be returned to the furnace and
reworked for the metals which they contain.
I am aware that it has been heretofore attempted to collect the wasto fumes of
lead sinelting furnaces in long flues, but in such a manner as to be expensive and
unsatisfactory.
I am also aware that a Patent has been granted for blowing pulverized argenti-
ferous ores of lead into a furnace and then passing the fumes through a showering
chamber to throw down the silver and afterwards collect the lead fumes in bags,
but the water employed to wash the fumes absorbed the sulphuric acid and the
vapor destroyed the bags.
I am also aware that textile fabrics have been employed with compound reducing
and oxydizing zinc furnaces, and also with compound reducing and oxydizing lead
furnaces, but no one has heretofore combined a series of cooling tubes and collecting
textile fabric with the lead smelting and refining furnaces so as to prevent the
waste incident to the processes of smelting or refining.
But my present improvements comprise the direct combination with the chimney
or shaft of a lead or smelting furnace or lead refining furnace of a series of metallic
cooling tubes and a series of bags of textile fabric, or their equivalent, as above
specified

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 19th
August 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. “IMPROVEMENTS IN APPARATUS FOR COLLECTING
THE WASTE FUMES OF FURNACES USED FOR SMELTING LEAD ORES." A com-
munication from abroad by George T. Lewis, of Philadelphia, Pennsylvania, United
States of America.
This Invention relates to apparatus for collecting waste fumes which incidentally
and necessarily escape from furnaces used for smelting lead ores.
In the process of smelting lead ores large amounts of volatile fumes necessarily
escape and are lost. These escaping fumes are found to be injurious to the sur-
rounding land. Various attempts have been heretofore made by passing these
escaping fumes through horizontal or ascending flues of great length to cause the
said fumes to be deposited, but these attempts have been attended with great
expense and have been only partially successful.
But the said George T. Lewis has discovered that by passing the escaping fumes
from a lead ore smelting furnace through a series of cooling tubes and then into a
series of bags the escaping fumes can be thoroughly and effectually strained out
and collected, while the attachment of the cooling tubes and collecting bags does
not interfere with the smelting operations.
A cooling and collecting apparatus constructed according to this Invention may
be used in combination with either of the ordinary lead-ore smelting or reducing
furnaces, such as the Scotch eye-furnace, the reverberatory smelting -furnace, or
the cupola-smelting furnace, or with the lead-refining furnace.
In the accompanying Drawings I have shewn the said apparatus as combined
with the stack of a Scotch eye reducing furnace.
B is the furnace proper in which the lead ore in admixture with carbon is
reduced; X is the furnace stack or chimney through which the fumes ascend.
(This ascending flue is common to all of the smelting furnaces or refining furnaces
above mentioned.)
A descending flue A leads from this stack to the commencement of a series of
vertical cooling tubes A¹ to A*, which are so arranged that the fumes are forced to
ascend and descend successively as they pass along through the said tubes. These
tubes are made of sheet-metal, as thin metal rapidly throws off the heat of the
contents and cools the fumes. The said tubes should be about two feet in diameter,
and the series should furnish about three hundred and fifty feet of aggregate length.
They can be cleaned out by openings with movable covers made in the lower part
of the flue if necessary, but the deposit will be very small.
The last tube of this series communicates with the eye of a fan H. The fumes are
drawn by this fan H through the series of cooling tubes and discharged into a
tube K which connects with a horizontal tube L. From this tube L is suspended a
series of strainers or bags M composed of textile fabric, through the meshes of
which the gases escape, leaving the solid material or fume proper within the bag or
strainer. Instead of textile fabric any similar straining material may be used.
The fumes so collected are composed of sulphate, sulphite, carbonate, and oxide
of lead when ordinary galena ore is smelted; when carbonate lead ores are smelted
the fumes collected will be found to consist of oxide and carbonate of lead mainly.
If the ores smelted are the argentiferous ores of lead then the fumes so collected
will contain in addition to the above mentioned salts of lead the corresponding salts
of silver. The fumes when collected in the said bags are removed therefrom by
shaking, and may be either used as a grey pigment direct, or after purification as a
whiter pigment; or these fumes may be returned to the furnace and re-worked for
the metals which they contain.

page_text: Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it under-
stood that I am aware that it has been heretofore attempted to collect the waste
fumes of lead smelting furnaces in long flues, but this process was found to be
expensive and unsatisfactory. I am also aware that a Patent has been granted for
blowing pulverized argentíferous ores of lead into a furnace and then passing the
fumes through a showering chamber to throw down the silver and afterwards
collecting the lead fumes in bags, but in this process the water employed to wash
the fumes absorbed the sulphuric acid and the vapour destroyed the bags. I am
also aware that textile fabrics have been employed with compound reducing and
oxidizing zinc furnaces, and also with compound reducing and oxidizing lead
furnaces, but no one has heretofore combined a series of cooling tubes and collecting
textile fabric with the lead smelting and refining furnaces so as to prevent the
waste incident to the processes of smelting or refining.
But the present improvements comprise the direct combination of the chimney or
shaft of a lead-ore smelting furnace or lead-refining furnace with a series of metallic
cooling tubes and a series of bags of textile fabric or equivalent devices, and I
claim,―
First. In combination with the stack of the ordinary lead-ore smelting furnace,
or lead-refining furnace, a cooling tube or flue and textile bags or receptacles for
collecting the escaping lead fumes, substantially as described.
Second. In combination with the stack of the ordinary lead-ore smelting furnace,
or lead-refining furnace, a series of cooling tubes, a fan or blower, and a series of
bags composed of textile fabric, for the purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Nineteenth day of August, in the year of our Lord One
thousand eight hundred and seventy nine,
W ROBT LAKE. (L.S.)