IMPROVE- MENTS IN THE MANUFACTURE OF WROUGHT IRON AND STEEL, AND. IN THE APPARATUS TO BE EMPLOYED THEREIN
Year: 1863

page_text: LETTERS, PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in
the County of Middlesex, Gentleman,. for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF WROUGHT IRON AND STEEL, AND. IN THE
APPARATUS TO BE EMPLOYED THEREIN." -A. communication from abroad by
Adrien Muller, of Paris, in the Empire of France, Manufacturer.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
5th May 1868.
I, JOHN. HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE MANUFACTURE OF WROUGHT IRON AND STEEL, AND IN THE
APPARATUS TO BE EMPLOYED THEREIN," a communication from abroad by
Adrien Muller, of Paris, in the Empire of France, Manufacturer, to be as
follows:-
This Invention relates to the manufacture or production in a blast furnace
of wrought iron and steel direct from the ore, and consists essentially in injecting
or blowing into the furnace with the blast finely divided oxide of iron. By this
system the decarburation of the cast iron is "accomplished in the blast furnace
itself, which thus supplies wrought iron or steel without the intervention of the
other furnaces and appliances hitherto required in the treatment of cast iron

page_text: with a view to its conversion into wrought iron or steel. Any other oxido
capable of producing the decarburation of cast iron may be blown into the
blast furnace, and other substances may be similarly employed with a view
to the purification or modification of the products.
In carrying out this Invention it is proposed to make the crucible of the
blast furnace deeper than usual, and to adapt thereto three tiers or ranges of
tuyeres. The upper set of tuyeres operate in the usual manner, whilst the
second or central set serve the double purpose of blowing in the oxide or other
substances employed, and of injecting a blast or blasts of air into the furnace.
The object of the lowest set of tuyeres is to prevent the caking of the oxide or
other.substance injected upon the fuel by maintaining a highly elevated tem-
perature at the part where these substances primarily enter the furnace. The
sides of the crucible of the furnace are protected by cast-iron jackets or wrought-
iron pipes, through which a circulation of cold water takes place. The hot
blast is employed for all the tuyeres.
In order to regulate the supply or distribution of the finely divided oxide
of iron or other oxides or substances, a double hopper is fitted to each of
the blast pipes intended to inject such substances into the "furnace, and a
revolving plug having chambers in its surface is fitted into the lower mouth of
the lower hopper just above the blast pipe, or in lieu of such plug an archime-
dian screw may be employed. The lower hopper is divided from the upper
one by a valve, and a similar valve or cover is fitted to the top of the upper
hopper. A rod or spindle is connected to the lower valve, and passes out through
the upper valve or cover; it is furnished with one or more arms or stirrers
whereby the charge which is first introduced into the upper hopper may be
stirred or agitated in order to facilitato its descent into the lower one when the
bottom valve is opened. In some cases a pipe communicates from the blast
pipe to the upper part of the lower hopper, so as to equalize the pressure in
the hopper and blast pipe. The oxides or other substances to be injected are
by preference heated to a dull red heat before-entering the blast pipe.
SPECIFICATION in: pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office
on the 5th November 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, send greeting.

page_text: .
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of May, in the year of our Lord
One thousand eight hundred and sixty-three,-in the twenty-sixth year of
Her reign, did, for Herself, Her beirs and successors, give and grant unto
me, the said John Henry Johnson, Her special license that I, the said
John Henry Johnson; my executors, administrators, and assigns, or such
others as I, the said John Ilenry Johnson, 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 Iuven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF WROUGHT IRON AND STEEL, AND
IN THE APPARATUS TO BE EMPLOYED THEREIN," a communication to me from
abroad by Adrien Muller, of Paris, in the Empire of France, Manufacturer,
upon the condition (amongst others) that I, the said John Henry Johnson,
my executors or administrators, by an instrument in writing under my hand
and seal, or under the hand and seal of one of them, 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 John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same is to bo
performed, 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:-
The said Invention relates to the manufacture or production in a blast
furnace of wrought iron and steel direct from the ore, and consists essentially
in injecting or blowing into the furnace with the blast firmly divided oxide
of iron. By this system the decarbonization of the cast iron is acconiplished
in the blast furnace itself, which thus supplys wrought iron or steel without
the intervention of the other furnaces and appliances hitherto required in the
treatment of cast iron with a view to its. conversion into wrought iron or
steel. Any other oxide capable of producing the decarbonization of cast iron
may be blown into the blast furnace, and other substances may be similarly
employed with a view to the purification or modification of the products.
In carrying out this Invention it is proposed to make the crucible of the
blast furnace deeper than usual, and to adapt thereto three tiers or ranges of
tuyeres: The upper set of tuyeres operate in the usual manner; the second or
H

page_text: central set serve the double purpose of blowing in the oxide or other substances
employed and of injecting a blast or blasts of air into the furnace, whilst the object
of the lowest set of tuyeres is to prevent the caking of the oxide or other
substance injected upon the fuel by maintaining a highly elevated temperature
at the part where these susbtances primarily enter the furnace. The sides of
the crucible of the furnace are protected by cast-iron jackets or wrought-iron
pipes, through which a circulation of cold water takes place. The hot blast
is employed for all the tuyeres.
In order to regulate the supply or distribution of the finely divided
oxide of iron or other oxides or substances, a double hopper is fitted to each
of the blast pipes intended to inject such substances into the furnace, and a
revolving plug having chambers in its surface is fitted into the lower mouth of
the lower hopper just above the blast pipe, or in lieu of such plug an archime-
dian screw may be employed. The lower hopper is divided from the upper
one by a valve, and a similar valve or cover is fitted to the top of the upper
hopper. A rod or spindle is connected to the lower valve, and passes out through
the upper valve or cover; it is furnished with one or more arms or stirrers
whereby the oxide or other substance which is first introduced into the upper
hopper may be stirred or agitated in order to facilitate its descent into
the lower one when the bottom valve is opened. In some cases a pipe com-
municates from the blast pipe to the upper part of the lower hopper, so as
to equalize the pressure in the hopper and blast pipe. The oxides or other
substances to be injected are by preference heated to a dull red heat before
entering the blast pipe.
And in order that the 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 several Figures on the Sheet of Drawing hereunto annexed,
the same letters of reference indicating corresponding parts in all the
Figures.
Figures 1 and 2 of the Drawings, represent respectively a vertical and
horizontal section of a blast furnace with the present improvements attached,
and Figures 8 to 6 inclusive are details on a larger scale of the apparatus for
facilitating the injection of the oxides or other substances employed. The
crucible portion of the furnace is protected by a jacket or jackets of cast iron
or by tubes of wrought iron, through which a circulation of cold water is main-
tained to prevent the eating away of the sides, and thus preserve a sufficiently
small diameter to ensure a very elevated temperature and a thorough mixing
of the oxides with the cast iron and slag. For the same purpose the blast
should be used at a pressure of not less-than, say, eight inches of mercury.

page_text: Hot air is blown in through the upper tuyeres A and lower. tuyères B,
whilst through the middle tuyeres C hot air in combination with oxides of iron
(rich ore) is blown in. These oxides should be employed in a finely divided'
state, and be well sifted before being injected; they should also be employed at
an elevated temperature, say, at a dull red heat; the continuous supply of
these substances is effected by the apparatus shown at Figures 3.to 6.' The
number of revolutions per minute made by the supply cocks of these distri-
butors regulates the proportion of oxide of iron injected into the furnace, and
-consequently the greater or less decarbonization of the cast iron.
Figure 8 is a vertical section of one arrangement of distributor and supply
regulating cock; Figure 4 is a sectional plan taken along the line 1, 2;
and Figure 5 is a vertical section taken at right angles to Figure 8. This
apparatus consists of two hoppers T, T, each closed by the valves S, S¹.
Beneath the hopper This fitted the distributing or supply cock D, the key
of which is formed by the axis d, which rotates at à convenient speed. The
oxide of iron which falls into the cavities of the cock descends into the passage,'
which corresponds. with the blast pipe E, terminated by a nozzel or tuyere.
This apparatus is charged by removing the cover of the upper-hopper T which
is then filled, and after the cover or valve S has been closed again the
valve S¹ is opened, allowing the powdered oxide to descend into the lower
hopper T. and into the cavities of the cock D. Certain arms fixed to tho
rod of the valve S¹ facilitate the stirring of the oxide and ensure its descent
into the lower hopper.
In order to preserve the same pressure under the lower hopper as in the
blast pipe E, a small branch pipe provided with a cock may be made to com-
municate between the blast pipe and the hopper, as shown in Figure 6. The'
combination of the two hoppers closed, as above described, admits of the charging.
of the same without loss or waste.
"
Figure 6 represents a vertical section of a distributing apparatus in which
the cock is replaced by an archimedian serew D which works inside the con-
tracted portion of the lower hopper T. This hopper is closed by the valve S¹;*
and the hopper T by the valve S. Motion is imparted to the screw by means'
of the grooved driving pulley fixed on to the end of the spindle or axis d. 'The
mode of charging is the same as for the previously described apparatus.' Down'
to the top tuyere or tuyeres A' the furnace operates in a similar manner to
other blast furnaces. The cast iron, in lieu of falling 'immediately into the
crucible portion of the furnace; continues to receive the action of a very elevated
temperature, and does not linger in front of the middle set of tuyeres to be

page_text: energetically mixed with the oxides of iron; it is transformed into steel, which
runs into the crucible. The lower tuyeres are necessary to prevent the obstruc-
tion of the tuyeres C, through which the oxide of iron is blown in. In effect,
the pieces, of coke, which are in immediate contact with the middle tuyere or
tuyeres, become covered with a black coating of cool ore, which would con-
tinue to increase and produce a cooling or lowering of the temperature. The
lowest tuyere or tuyeres B, by producing a rapid descent of the coke in front
of the upper tuyeres, secure always a free entrance for the oxide, and by keeping
up the temperature enable the crucible to operate in a proper manner.
It will be seen that the reaction upon which is based this process of decar-
bonization of cast iron by means of oxide of iron necessitates, first, that tho
oxide of iron be not reduced in the locality of the tuyeres by the gases or fuel;
second, that the slag be as basic as possible in order that the oxide of iron be
not dissolved in the mass of slag by an excess of silica. The first condition is
a fact easily verified by experiment, the second necessitates a proper regard to
the quantities. A slag highly, destructive to the furnace is obtained, which
renders necessary the protection of the sides thereof by water jackets, as herein-
before described.
This process at the first glance will appear a contradiction to that employed
for zinc. It is not so, however; the oxide of zinc injected by the tuyere
becomes totally reduced, whilst the oxide of iron in the same conditions is not
reduced; the reason is plain, the oxide of zinc tends to render the slag infusible,
and the oxide of iron tends on the contrary to render them fusible. This is
one reason why the silicates of zinc form only with difficulty, and those of iron are
produced before reduction, in other words, in contact with the fuel the oxide
of zinc tends to give a volatile product, zinc. The oxide is destroyed the
moment it touches the fuel, and if it is reformed it is carried off with the gases
into the upper reducing zones, whilst the oxide of iron being capable only of
giving a fixed product, the fusion of the oxide takes place before its reduction
'can be effected in an atmosphere of such small reducing powers as that in the
zone of the tuyeres. It is obvious that this system may be applied to tho
treatment of other metals, particularly in the treatment of zinc in the blast.
furnace, in which the addition of the upper or third tuyere or set of tuyeres will
I have the effect of raising the temperature of the upper part of the furnace to
the greatest possible extent, and consequently to force to its farthest limits the
transformation of the carbonic acid into carbonic oxide.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried

page_text: into effect, I would observe, in conclusion, that what I consider 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 system or mode of manufacturing wrought iron and steel,
and the combination of apparatus to be employed in such manufacture, as
herein-before described.
Second, the blowing in of oxides of iron in combination with air when
working blast furnaces for the purpose herein-before described.
Third, the decarbonization of cast iron in the blast furnace and its conversion
into steel or wrought iron in the manner herein-before described.
Fourth, the blowing into a blast furnace of any oxide capable of pro-
ducing the results above described, or of any substance capable of purifying or
modifying the products.
Fifth, the herein-before described peculiar constructions and arrangements
of distributing apparatus and their application in combination with the process
of insufflation above referred to in the treatment of metals generally.
In witness whereof, I, the said John Henry Johnson have hereunto set
my hand and seal, this Fourth day of November, One thousand eight
hundred and sixty-three.