IMPROVEMENTS RELATING TO BLAST AND CUPOLA URNACES
Year: 1867

page_text: LETTERS PATENT to James Addie, of the Langloan Ironworks, Coat-
bridge, in the County of Lanark, Ironmaster, and Ferdinand Kohn, of
Westminster, in the County of Middlesex, Civil Engineer, for the
Invention of "IMPROVEMENTS RELATING TO BLAST AND CUPOLA
URNACES.
PROVISIONAL SPECIFICATION left by the said James Addie and Ferdinand
Kohn at the Office of the Commissioners of Patents, with their Petition,
on the 24th December 1867.
We, JAMES ADDIE, of the Langloan Ironworks, Coatbridge, in the
County of Lanark, Ironmaster, and FERDINAND KOHN, of Westminster,
in the County of Middlesex, Civil Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS RELATING TO BLAST AND CUPOLA
FURNACES," to be as follows, that is to say:-
This Invention bas for its object to improve and economise the working of
blast and cupola furnaces, by utilising in a better manner than heretofore the
combustible gases produced in such furnaces, and which are ordinarily either
allowed to escape or collected and burned in flues and stoves for the purpose
of generating steam and heating the blast.

page_text: And the Invention consists in reintroducing a portion of the combustible
gases either alone or mixed with other gases into the furnace itself at or near
the tuyeres which supply the air blast.
The effect of the improvements is to produce a flame in front of the tuyeres,
which flame is due to the combustion of the gases drawn off the top and
reintroduced into the furnace itself. The arrangements for drawing off gases
from the tops of blast and cupola furnaces are now generally known and form
no part of the present Invention. In reintroducing the combustible gases it
is preferred to use a double concentric tuyere in the well known form of a jet
pump or injector, that is to say, a tuyere with an annular passage round it for
the combustible gases so that the central blast jet will induce an inward
current of these gases. Only a portion of the furnace gases can be employed
in this manner, the remainder may be used for heating boilers or stoves or it
may be allowed to escape. The gases to be reintroduced into the furnace
sometimes require purifying from steam, sulphurous acid, and other impurities
and to effect this they are cooled so as to condense the steam and bring down
some of the impurities with the water thus formed. In some cases it may be
convenient to add special gas producers such as are used for feeding gas fired
furnaces and in such cases the gas so produced is by this Invention to be
drawn into the blast or cupola furnace by the jet action of the air blast in the
manner herein-before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Addie and Ferdinand Kohn in the Great Seal Patent
Office on the 23rd June 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
ADDIE, of the Langloan Ironworks, Coatbridge, in the County of Lanark,
Ironmaster, and FERDINAND KOHN, of Westminster, in the County of
Middlesex, Civil Engineer, send greeting.
:
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of December, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said James Addie and Ferdinand Kohn, Her special licence that we, the
said James Addie and Ferdinand Kohn, our executors, administrators, and
assigns, or such others as we, the said James Addie and Ferdinand Kohn, our
executors, administrators, and assigns, should at any time agree with, and no

page_text: 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 RELATING TO BLAST AND CUPOLA FURNACES,"
upon the condition (amongst others) that we, the said James Addie and
Ferdinand Kohn, our executors or administrators, by an instrument in writing
under our, 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.
NOW, KNOW YE, that we, the said James Addie and Ferdinand Kohn, do
hereby declare the nature of our said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement in writing, reference being had to the accompanying
Drawings, that is to say :-
Our said Invention has for its object to improve and economise the working
of blast and cupola furnaces by utilising in a better manner than heretofore
the combustible gases produced in such furnaces, and which are ordinarily
either all wed to escape or collected and burned in flues and stoves for the
purpose of generating steam and heating the blast.
And our said Invention consists in reintroducing a portion of the combustible
gases either alone or mixed with other gases into the furnace itself at or near
the tuyeres which supply the air blast.
The effect of our improvements is to produce a flame in the furnace in
front of the tuyeres, which flame is due to the combustion of the gases drawn
off from the top and reintroduced into the furnace itself.
The arrangements for drawing off gases from the tops of blast and cupola
furnaces are now generally known and form no part of our present Invention.
In reintroducing the combustible gases we prefer to use a double concentric
tuyere in the well known form of a jet pump or injector, that is to say, a
tuyere or jet pipe with an annular passage round it for the combustible
gases so that the central blast jet will induce an inward current of these
gases.
And in order that our said Invention and the manner of performing the
same may be properly understood we have hereunto appended a Sheet of
explanatory Drawings to be herein-after referred to and representing by way of
example a convenient and practically successful arrangement of parts for
carrying our Invention into effect.

page_text: The Drawing is a vertical section showing the lower part of the furnace
wall at one of the tuyere arches and the parts in connection with the tuyere 1.
The gas drawn off from the top of the furnace descends by a pipe 2 into a
holder or chest 3, which contains some water, and the bottom end of the
pipe 2 dips just below the surface of this water, and the gas has to pass through
it, whereby it is purified from steam, sulphurous acid, and other impurities.
The gas leaves the chest 3 by a pipe 4 which is connected by a length 5 to
the tuyere 1. The air blast from the pipe 6 enters the pipe 4 by a tapered
jet pipe or nozzle 7 inserted concentrically a short distance into the pipe 4.
This arrangement forms an annular passage 8 for the gas from the chest 8 to
have access to and surround the blast jet, and for it to be drawn forward and
be propelled into the furnace by the well understood action of the jet. Only
a portion of the gases drawn off from the top of the furnace can be used in
the manner indicated, and the remainder may be used for. heating boilers or
stoves, or it may be allowed to escape. In some cases it may be convenient
to add special gas producers such as are used for feeding gas-fired furnaces,
and in such cases the gas so produced is by our present Invention to be drawn
into the blast or cupola furnace by the jet action of the air blast in the manner
herein-before described.
Having thus particularly described our said Invention, and the manner in
which the same is to be performed, 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
the herein-before in part recited Letters Patent is, the reintroducing of a
portion of the combustible gases drawn off from blast or cupola furnaces
substantially in the manner herein-before described.
In witness whereof, I, the said James Addie, on behalf of myself and
the said Ferdinand Kohn, have hereunto set my hand and seal, this
Twenty-second day of June, in the year of our Lord One thousand
eight hundred and sixty-eight.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JAMES ADDIE. (L.S.)