IMPROVEMENTS IN UTILISING THE GASES OF BLAST FURNACES, AND IN APPARATUS OR ARRANGEMENT THEREFOR
Year: 1879

page_text: LETTERS PATENT to John Alexander and Andrew Kirkwood M°Cosh, of
Gartsherrie Iron Works, in the County of Lanark, North Britain, for the
Invention of "IMPROVEMENTS IN UTILISING THE GASES OF BLAST FURNACES,
AND IN APPARATUS OR ARRANGEMENT THEREFOR."
Scaled the 6th April 1880, and dated the 11th October 1879.
PROVISIONAL SPECIFICATION left by the said John Alexander and Andrew
Kirkwood M Cosh at the Office of the Commissioners of Patents on the 11th
October 1879.
JOHN ALEXANDER and ANDREW KIRKWOOD McCoSH, of Gartsherrie Iron Works,
in the County of Lanark, North Britain. "IMPROVEMENTS IN UTILISING THE ĜASES
OF BLAST FURNACES, AND IN APPARATUS OR ARRANGEMENTS THEREFOR'
"
This Invention has for its object to utilise blast-furnace gases in an improved
manner, and so as to obtain valuable products therefrom, and thereby reduce the
cost of iron smelting.
In carrying out the Invention the gases are led from the furnace by a vertical
pipe rising from the centre of the top, the top being closed in by a dome, at the
The central
Bides of which are doors for introducing the ore and other materials.
vertical pipe is a few feet in height which allows the gas to partially free itself
from dust; and the gas next proceeds by a horizontal pipe to a vertical pipe at the
side of the furnace, and it descends by such vertical pipe on its way to apparatus
provided for separating condensible matters from it. This apparatus consists in the
first place of an air condenser comprising a number of vertical pipes exposed to the
atmosphere, and arranged like the condensers used in the manufacture of illumi-
nating gas, being provided with suitable outlets for withdrawing tar and other
liquefied matters. The gases are next passed through scrubbers or washing
apparatus to remove ammoniacal and other soluable volatile matters, and if found
desirable the gases may also be passed through lime purifiers, or other chemical
purifiers. The proper movement of the gases through the several parts of the
apparatus is insured by employing a fan or other blowing machine, such fan being

page_text: by preference applied beyond the apparatus so as to draw the gases through, and
so that the gases may pass through the fan after having been purified. From the
fan the gases proceed to the stoves for heating the blast, and to the furnaces of steam
boilers, or to other furnaces, being more advantageously and conveniently
applicable in such stoves and furnaces than the unpurified gases bitherto used 5
therein.
When two or more blast furnaces are near together a single set of the purifying
apparatus is provided for all the furnaces, and two main pipes are placed along the
series of furnaces, one of such main pipes receiving the gases from the descending
pipes of the several furnaces and leading them to the purifying apparatus, and the 1
other main pipe receiving the purified gases, and supplying the several heating
stoves and boiler or other furnaces by branch pipes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Alexander and Andrew Kirkwood McCosh in the Great Seal
Patent Office on the 9th April 1880.
JOHN ALEXANDER and ANDREW KIRKWOOD McCoяH, of Gartsherrie Iron Works,
in the County of Lanark, North Britain. "IMPROVEMENTS IN UTILISING THE
GASES OF BLAST FURNACES, AND IN APPARATUS OR ARRANGEMENTS THEREFOR.”
Our said Invention has for its object to utilise blast-furnace gases in an improved
manner, and so as to obtain valuable products therefrom, and thereby reduce the
cost of iron smelting.
In carrying out our Invention the gases are led from the blast furnace by a
vertical pipe rising from the centre of the top, such pipe being a few feet in height
to allow the gas to partially free itself from dust. The gas proceeds by a horizontal
pipe to a vertical pipe at the side of the furnace, down which it descends on its way
to apparatus provided for separating condensible matters from it. This apparatus
comprises in the first place condensers consisting of pipes exposed to the atmosphere
and arranged like condensers used in the manufacture of illuminating gas, being
provided with suitable outlets for withdrawing tar and other liquefied matters.
The gases are next passed through scrubbers or washing apparatus to remove
ammoniacal and other soluble volatile matters; and if found desirable the gases may
also be passed through lime purifiers, or other chemical purifiers. The proper move-
ment of the gases through the several parts of the apparatus is insured by
employing a fan or other blowing machine, such fan being by preference applied
beyond the apparatus, so as to draw the gases through, and so that the gases
may pass through the fan after having been purified.
From the fan or blower the gases proceed to the stoves for heating the blast,
and to the furnaces of steam boilers, or to other furnaces, being more advan-
tageously and conveniently applicable in such stoves and furnaces than the
unpurified gases hitherto used therein.
When two or more blast furnaces are near together the purifying apparatus for
all the furnaces is combined, and two main pipes are placed along the series of
furnaces, one of such main pipes receiving the gases from the descending pipes of
the several furnaces, and leading them to the purifying apparatus, and the other
main pipe receiving the purified gases and supplying the several blast heating stoves
and the boiler or other furnaces by branch pipes.
As is well known, the gases proceeding from blast furnaces comprise a large
proportion of carbonic oxide gas, which differs from illuminating gas chiefly in
having some oxygen in place of the hydrogen of the latter, and in being unsuitable
for illuminating purposes, although capable of developing considerable beat on
combustion. The carbonic oxide gas has commonly associated with it, more
particularly when coal is used in the blast furnace along with or instead of coke,
gaseous hydrocarbons (and other matters), which gaseous hydrocarbons whilst
enriching it have caused considerable trouble and inconvenience when the gases
have hitherto been employed for heating purposes, by their becoming deposited to
a considerable extent in a tarry form in the pipes and ducts and in the apparatus
in which they have been burned. Various apparatus and arrangements have been
proposed and tried for diminishing the inconvenience due to the tarry deposits, and
it has also been proposed to utilise them; we however believe that no completo
separation, nor any satisfactory utilisation has ever heretofore been effected in
practice of the condensible or soluble constituents of the gases; and it is the main
object of our Invention to effect such separation and utilisation in such a manner
as not only to avoid inconveniences and expenses hitherto experienced, but also

page_text: to obtain products, the value of which will be equivalent to a considerable reduction
in the cost of iron smelting.
Apart from the special arrangements and parts of apparatus designed for adapting
the separating and purifying apparatus to blast furnaces, the apparatus which we
employ in carrying out our Invention is analogous to that used in purifying
ordinary illuminating gas, and may in fact be made like any of the several existing
modifications of such apparatus that may be found capable of being conveniently
made of the requisite capacity, and otherwise suitable. In order however that our
said Invention and the manner of performing the same may be properly understood
we hereunto append three Sheets of explanatory Drawings to be hereinafter
referred to, and representing an arrangement of apparatus for the purposes of our
Invention. In these Drawings the same reference numerals are used to mark the
Bame or like parts wherever they are repeated.
Figure 1, on Sheet 1, of the accompanying Drawings is a side elevation showing
two of a series of blast furnaces and the arrangement of pipes for leading the gases
from them; Figure 2 is a transverse vertical section corresponding to Figure 1;
Figure 3, on Sheet 2, and Figure 4, on Sheet 3, are a plan and a vertical section of
a portion of the purifying apparatus.
The top of the blast furnace is closed in by a dome 5, from the centre of which
there rises a vertical pipe 6 to lead off the gases, whilst round the central pipe
there are doors 7 for charging in the ore and other materials. The pipe 6, which
is a few feet in height to allow the gas to partially free itself from dust, commu-
nicates by a horizontal pipe 8 and a vertical pipe 9 at the side of the furnace with a
horizontal main 10 running along the series of furnaces and collecting the gasos from
them. The pipe 6 also communicates with an upper open topped pipe or funnel 11
by which the gases can be allowed to pass off when it is not wished to lead them
down the side pipe 9. A valve 12 is provided for closing the communication with
the open funnel 11, a similar valve 13 being provided for closing the side pipe 9,
and these two valves 12, 13, are moved by chains and rods arranged in connection
with a double pulley 14, so that one may be closed when the other is opened. A
smaller valve 15 is also provided for communicating between the pipe 8 and the
open funnel 11, so that when it is desirable a small portion of the gases passing to
the side pipe 9 may be allowed to escape. When opening the doors 7 for charging,
the valve 13 in the side pipe 9 is temporarily closed and the outlet valve 12
opened. The pipes 6, 8, 9, 10, are protected by a lining of any suitable refractory
material.
The horizontal main 10 which receives the gases from the series of furnaces is by
preference continued beyond one end of the series, and this continuation of the
main is put in communication by pipes 16 with the requisite number of sets of
ntinosperic condenser pipes 17, which have the usual bottom tar collecting troughs,
and of which a few sets are shown in Figures 3 and 4. From the condenser pipes
17 the gas passes by pipes 18 into the lower parts of a number of scrubbing
columns 19, of which two are shown in Figure 3, one being shown in vertical
section in Figure 4. In each scrubbing column 19 there are a number of horizontal
diaphragms 20, which may consist of boards perforated with holes, or of perforated
metal plates, and which are placed so as to leave openings for the passage upwards
of the gas at opposite sides alternately. Water is admitted by a pipe 21 at the
top, and dripping downwards as the gas proceeds upwards, absorbs ammonia and
other soluble volatile impurities from the gas. The water collecting at the bottom
of the column passes off by a siphoned outlet 22 to a depositing tank 23, whilst
tarry matter can be drawn off by a lower outlet 24 to a tar tank 25, which also
receives the tar deposited in the tank 23. The purified gas passes from the tops
of the scrubbing columns 19 by pipes 26 to one or more blowing fans 27, which by
its exhaust action causes the gas to be properly drawn through the separating
or purifying apparatus, and which delivers the purified gas into a return or
distributing main 28. This return or distributing main may be arranged, as shown,

page_text: alongside of the collecting main 10, or in whatever other position relatively to the
furnaces may be found most convenient in each case. The return or distributing
main 28 may have branch pipes connected to it at convenient points for leading
the gas to the blast heating stoves, and to steam boiler, and other furnaces. In
Figure 3 an engine 29 is shown for driving the fan 27, and for working pumps 30
for supplying water to the tops of the scrubbing columns.
Instead of employing sets of atmospheric condenser pipes (17), as herein before
described, we now believe that a more economical and compact apparatus may be
used wherein water is employed as the cooling medium, and is made to act on the
outside of metal passages or chambers through which the gas is passed. We prefer
to employ improved apparatus of this kind for which we have applied for Letters
Patent on the Eighth day of April 1880.
Having thus particularly described our said Invention and the manner of
performing the same, we have to state that we do not restrict ourselves to the
precise details herein described or delineated, but that what we believe to be novel
and original and claim as the Invention secured to us by and in terms of the
herein before in part recited Letters Patent is,-
1. The utilisation of blast furnace gases in the improved manner, and by means
of the improved combination of collecting, condensing, purifying, or scubbing, and
distributing apparatus, substantially as hereinbefore described.
2. The arrangement of pipes and valves for leading the gases from blast furnaces
combined with condensing and purifying apparatus, and with a fan or equivalent
machine for drawing the gases through the combination of apparatus, substantially
as and for the purposes hereinbefore described.
In witness whereof, we, the said John Alexander and Andrew Kirkwood
McCosh, have hereunto set our hands and seals, this Seventh day of April,
in the year of our Lord One thousand eight hundred and eighty.
Witness,
JOHN RANKIN,
168, West George Street,
Glasgow,
Clerk.
JOHN ALEXANDER. (L.S.)
AND. K. McCOSH. (L.S.)