IMPROVEMENTS IN THE METHOD AND APPARATUS FOR THE RECOVERY OF LEAD AND OTHER METALLIC SUBSTANCES FROM FURNACE FUMES."
Year: 1880

page_text: LETTERS PATENT to Edward Alfred Cowper and Thomas Sopwith, both of
No. 6, Great George Street, Westminster, in the County of Middlesex, for an
Invention of "IMPROVEMENTS IN THE METHOD AND APPARATUS FOR THE
RECOVERY OF LEAD AND OTHER METALLIC SUBSTANCES FROM FURNACE
FUMES."
PROVISIONAL SPECIFICATION left by the said Edward Alfred Cowper and
Thomas Sopwith at the Office of the Commissioners of Patents on the 8th
July 1880.
EDWARD ALFRED COWPER and THOMAS SOPWITH, both of No. 6, Great George
Street, Westminster, in the County of Middlesex. "IMPROVEMENTS IN THE METHOD
AND APPARATUS FOR THE RECOVERY OF LEAD AND OTHER METALLIC SUBSTANCES
FROM FURNACE FUMES."
It is well known that to a certain extent the lead and other metallic substances
suspended in the gases or products of combustion from furnaces are deposited in
very long flues or large chambers, and that the longer the flue is made the more of
the metallic substance is deposited. By numerous experiments we have found that
in these cases the deposit takes place very imperfectly and slowly, especially if the
velocity of the current is such as to cause the scouring or carrying forward of the
suspended matter, and that ordinary flues of the size hitherto used, large enough to
ndmit a workman, are of such height that a very considerable time must elapse
before the suspended matter can fall through the height of the flue. According to
our Invention we cause the current of the fumes to be so slow as to prevent any
scouring action taking place, and in order very greatly to reduce the time required
for the solid matter to fall we place inside the fluo a number of shelves (preferably
moveable) at small distances one above the other, so that the suspended matter in
each layer of the fumes has a very small height to fall. By passing the fumes
through a number of flues, each subdivided by numerous shelves, wo cause tho
movement of the current to be very slow, and thus we obtain a very thorough
deposit of the suspended matter in a comparatively short distance.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Alfred Cowper and Thomas Sopwith in the Great Seal
Patent Office on the 29th November 1880.
EDWARD ALFRED COWPER and THOMAS SOPWITH, both of No. 6, Great George
Street, Westminster, in the County of Middlesex. "IMPROVEMENTS IN THE METHOD
AND APPARATUS FOR THE RECOVERY OF LEAD AND OTHER METALLIC SUBSTANCES
FROM FURNACE FUMES."
It is well known that to a certain extent the lead and other metallic substances
_suspended in the-gases-or-products-of-combustion-from-furnaces-aro- deposited-in-
very long flues or large chambers, and that the longer the flue is made the more of
the metallic substance is deposited. By numerous experiments we have found that
in these cases the deposit takes place very imperfectly and slowly, especially if the
velocity of the current is such as to cause the scouring or carrying forward of the
suspended matter, and that ordinary flues of the size hitherto used, large enough to
admit a workman, are of such height that a very considerable time must elapse
before the suspended matter can full through the height of the flue. According to
our Invention wo cause the current of the fumes to be so slow as to prevent any
scouring action taking place, and in order very greatly to reduce the time required
for the solid matter to fall, we place inside the flue a number of shelves (preferably
moveable) at small distances one above the other, so that the suspended matter in
-each--layer--of-the-fumes-has a very small-height to fall. By passing-the-fumes-
through a number of flues, each subdivided by numerous shelves, we cause tho
movement of the current to be very slow, and thus we obtain a very thorough
deposit of the suspended matter in a comparatively short distance. The apparatus
which we employ in this manner may be varied in its form and proportions to suit
particular circumstances and situations. We will describe a convenient arrangement
referring to the accompanying Drawings. Fig. 1 is a half plan showing a set of
depositing chambers in connection with a central flue from a furnace. Figs. 2 and 3
aro respectively transverse and longitudinal sections (drawn to an enlarged scale)
of part of the depositing chambers. The central furnace flue A, A', has at its sides
numerous small passages B branching off from it at an acuto angle, each of these
passages leading into one of the depositing chambers C. From the opposite end of
each chamber there is a similar passage B' leading into a flue E which joins the
main flue at A. In the main flue beyond the last of the passages B there is a
valve or damper D, by closing which the whole of the fumes are caused to pass
through the depositing chambers, and each of the inlets B which is of small area
may be more or less closed by a separate valve or damper, so as to detorinine a very
slow movement of the fumes through the chamber, or to exclude the fumes from
any of the chambers when workmen enter them to remove the matters deposited in
them. For the purpose of access there are manholes H in the roofs of the chambers,
the manholes in each case admitting to a space I of couvenient size for a workınan
to operate in. Between the spaces I the chambers are fitted with numerous
shelves F, which may be, as shewn, sheets of corrugated iron resting on fillets G
projecting from the partition walls, each shelf being capable of being, readily
removed and replaced.
The fumes being prevented by the damper D from passing directly. along the
central flue A, A, find their way by the oblique passages B into the depositing
chambers C, in which, in consequence of the enlarged area for their passage, they
move very slowly. They are moreover subdivided by the shelves F into numerous
very shallow layers, so that the matters suspended in them have to descend by
gravity only a very small distance in each layer, and therefore become in a very
short time deposited on the shelves, from which they are from time to time removed
by workmen entering the chambers by the manholes H.

page_text: Having thus described the nature of our Invention and in what manner the
same is to be performed, we claim,―
First. The method of recovering lead and other suspended metallic substances
from furnace fumes, by causing these fumes to move very slowly in shallow layers
into which they are subdivided by shelves that receive the deposited matters,
substantially as herein described.
Second. The construction of apparatus for recovering lead and other metallic
substances from furnace fumes, substantially as herein described with reference to
the accompanying Drawings.
In witness whereof, I, the said Edward Alfred Cowper, have hereunto set
my hand and seal, this Twenty sixth day of November, in the year of our
Lord One thousand eight hundred and eighty.
EDWARD ALFRED COWPER. (L.s.)