IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN APPA- RATUS EMPLOYED THEREFOR
Year: 1874

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn.
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN APPA-
RATUS EMPLOYED THEREFOR."-A communication from abroad by Edgar
Peckham, of Antwerp, in the County of Jefferson, State of New
York, United States of America.
COMPLETE SPECIFICATION filed by the said John Henry Johnson-
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 28th May 1874, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middle-
sex, Gentleman, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF IRON AND STEEL, AND IN APPARATUS EMPLOYED THEREFOR,"
and have petitioned Her Majesty to grant unto me, my executors,

page_text: administrators, and assigns, Her Royal Letters Patent for the same, and
have made solemn Declaration that the said Invention is communica-
ted to me from abroad by Edgar Peckham, of Antwerp, in the County
of Jefferson, State of New York, United States of America.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention,
and in what manner the same is to be performed in and by the following
statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thercon, that is to say :-
In order to obtain a uniform quality of iron or steel direct from the
ore by a process which involves the preliminary treatment of the ore with
carbon in air-tight retorts, it is necessary, first; that the ore to be treated
should be reduced to a uniform size or very nearly so, and should be
evenly and uniformly mixed in the retorts with the required per centage
of coal, and in such manner that the same per centage of carbon, and
the same uniformity of mixture can be maintained at each operation;
second, that the ore being thus uniformly mixed with the proper per
centage of carbon, should be brought up to the desired temperatures
necessary to its deoxidation and carbonisation by degrees, and in such a
manner that the required temperatures can be steadily and uniformly
maintained in the retorts the necessary time required to deoxidize and
carbonize it; third, that the ore being properly treated should be trans-
ferred directly to the reducing fire or furnace (without coming into
contact with any cold air), and there properly separated from its
impurities during its manipulation into iron or steel.
.
This Invention is directed mainly to the realization in a practical and.
inexpensive manner of these conditions.
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
shall refer to the several Figures on the annexed Sheet of Drawings, the
same letters of reference indicating corresponding parts in all the
Figures.
..
Figure 1 is a longitudinal vertical section of a furnace on the line a, b;
Figure 4; Figure 2 is a like section on the line c, d, Figure 4; Figure 3
is a like section on the line e, f, Figure 4; Figure 4 is a plan view of
the furnace with top removed; Figure 5 is a transverse vertical section
:

page_text: referred to.
A, A, represent the main walls of the converting furnace; P, P,
represent the cross walls or sections of the converting furnace preferably
constructed of fire-bricks having tongues 1 on their upper sides, and
grooves 2 on their lower sides (Figure 3); they also have grooves 3
(Figure 4) in their sides at certain stated intervals to correspond with
the thickness of the tiles o, o, o, used for the partition walls separating
the flues from the retorts. The cross walls P and tile partitions o form
the upright retorts B, which are provided with removable covers, in
which small perforations may be made to permit escape of gases evolved
from the charges in the retorts. On each side of each retort is a vertical
fluc C, the two flues of each retort serving to heat the same. All thesc
flues are entirely distinct and independent of each other, communicating
at the bottom (Figure 5) with the main horizontal supply flues H,
through which the waste heat from the reducing fire or furnace is con-
veyed to and distributed among the upright flues, and at the top with
horizontal escape flues N leading to the chimney stack. The communi-
cation between each upright flue C and its escape flue N is controlled by
a damper or valve 4, so that the heat in any one retort may be graduated
to any degree irrespective of and without affecting the others.
In the furnace are ten retorts arranged in two parallel rows of five
cach. Beneath each row of retorts is a closed receiving chamber E into
which the charge from cach retort of the row can be dropped, the bottom
of the retorts being for this purpose closed by sliding dampers 5. The
ore is retained in these chambers ready for transfer, as required, to the
forge fire or puddling furnace connected with the converting furnace.
When combined with a forge fire as at D in Figures 1 and 2, cach
chamber communicates with..D by a passage J provided with a damper b,
which is closed when it is not required to transfer the ore from the
chamber. E' is an elevated rear portion of the receiving chamber E
upon which the ore from the retorts situated above this portion of the
chamber is discharged. From this elevated part E¹ the ore can be trans-
ferred (by operating through the door m³) to the lower front part of the
chamber E. When attached to puddling furnaces the receiving
chambers E are made as seen in Figures 7, 8, and 9, each chamber
having a depression at about its centre with its sides sloping towards this

page_text: depression, leading from which is the inclined air-tight chute or passage
D¹ (Figure 7) through which the ore is discharged upon the hearth of the
puddling furnace R. The chute or passage D' is provided with a
damper or slide by which communication with the puddling furnace may
be cut off, except when it is required to supply the furnace with the
prepared ore. Of the Figures just referred, Figure 7 is a side clevation,
and partly longitudinal section, the line of section being through the
outer vertical heating flues. Figure 8 is a longitudinal vertical section
through the row of retorts adjoining said outer heating flues. Figure 9
is a transverse vertical section shewing the puddling furnaces one on
each side. F is a horizontal flue located between the chambers E
answering the double purpose of a waste flue for carrying direct to the
main stack or chimney any and all surplus heat not required to heat the
retorts, and also to heat the horizontal receiving chambers.
valve or damper to govern it.
It has a
It is essential that the ore and charcoal should be charged into the
retorts in exact and uniform quantity, and that the two substances should
be thoroughly and evenly mixed or distributed through the retorts. In
Figures 4, 5, and 6, I have shewn a charger for this purpose. The
charger K (shown in Figure 6 in vertical central section transverse to
its partitions) is made of light shect iron divided by vertical partitions
into spaces or sections of any requisite number, their dimensions
depending upon the per centage of carbon to be mixed with the ore in
the retorts. The sectional area of the charger is such that it will fit
snugly but not too tightly in any one of the retorts B in which it may
be inserted.
ore.
:
The sections 8, 8, 8,
In the charger shewn there are five sections.
are designed for the coal, and the intermediate sections 9, 9, 9, for the
The charger is provided with two removable and interchangeable
tops or hoppers K', K², the former having openings in its bottom corre-
sponding to the ore sections 9, 9, and the latter having openings in its
bottom corresponding to the coal sections 8, 8, 8. The charger is placed
in the retort to be charged. The top K² may be first applied, and the
coal filled in, occupying the spaces indicated by 8, 8, 8. The top K² is
then replaced by K', and the ore is filled in entering the spaces 9, 9.
The charger is then withdrawn, and the coal and ore will remain in
parallel or vertical layers, as represented, the coal being on the outside
next to the sides of the retort. In this way much labor and trouble is

page_text: saved in the charging operation, and a uniform mixture of coal and ore
in alternate layers of ascertained and determinate quantities and pro-
portions is insured.
The process of treating the ore, to the carrying out of which the above
furnace is adapted, consists essentially in the treatment of the ore mixed
with carbon or coal in air-tight or substantially air-tight retorts at
different degrees of temperatures with first a low heat a sufficient length
of time to remove its water and open or disintegrate it; then at an
increased heat the proper length of time to deoxidize it, and then at a
still higher heat, the duration of which will depend upon the per centage
of carbon to be taken by the ore.
When manufacturing iron and steel the operation is conducted in the
following manner :-The ore should be separated from all earthy matter,
and reduced to a uniform size, as near as may be about the size of coarse
shot, and the coal to be used should also be reduced to a uniform size.
This being done the bottom of the retort or retorts to be charged should
be covered with coal to about the depth of four inches, after which
they are charged with coal and ore by the use of a charger K, as above
described.
After charging the retorts (fire having been previously made in the
reducing fire or furnace attached to the converting furnace) the valves 4
(Figures 5 and 7) of flues C should be opened to cause sufficient draft to
heat the flues to a dark cherry red heat. This heat should be main-
tained for about twelve hours, or sufficient time to remove the water
from the ore, open its pores, and heat it throughout to a cherry red.
Then the valves 4 should be opened a little more to raise the heat to a
deep full cherry red, and this heat should be maintained for about twelve.
hours, or sufficient time to deoxidize the ore. When thus deoxidized it
is ready to be made into iron in the forge fire, or indeed in the puddling
furnace as well. But it is preferred to carry the process still further,
and to carbonize the ore, which is done by opening the valves 4 sufficiently
to raise the heat in the flues to a very bright cherry red, which heat
should be maintained a sufficient length of time to carbonize the ore to
the desired extent. The ore is then dropped from the retorts into the
receiving chambers E underneath, from which it can be transferred as"
required to the puddling furnace or forge fire.

page_text: In lieu of the arrangement above described the same result is accom-
plished by dividing each retort into different zones or belts, whereby the
ore contained in one retort may be subjected to different but exactly
determined heats, according to the zone in which it is situated, all the
ore passing through these several zones, and being subjected successively
to the predetermined and ascertained heats, which are imparted to said
zones severally. Furnaces for this purpose are shewn in Figures 10, 14,
inclusive.
Figure 10 is a longitudinal vertical section on the line 1-2, Figure 13,
for the converting furnace, and the line 3-4, same Figure, for the pud-
dling furnace; Figure 11 is a like section on line 5-6, Figure 13;
Figure 12 is a like section on line 7-8, Figure 13; Figure 13 is a plan
of the apparatus with the top of the converting furnace removed;
Figure 14 is a transverse vertical section on linė 9-10, Figure 13.
A, A, represent the main walls of the converting furnace, which may
be constructed of brick or stone; P, P, (Figure 13), the horizontal main
partition walls, which in this furnace are constructed of fire-brick,
having tongues on their upper and corresponding grooves in their lower
sides. They also have grooves in their sides corresponding with the
thickness of the tiles used for the cross walls separating the retorts,
constituting vertical guides or grooves, into which the said tiles P¹ are
fitted, as indicated in Figure 4.
The perpendicular retorts B for treating the ore are divided by means
of the external horizontal heating flues C, C¹, and C² into sections or
zones B1, B2, and B³ (Figure 14). The horizontal flues C on each side of
the retorts B, B, correspond with the sections or zones B¹, B¹; C¹, C¹, C¹³,
correspond with the sections or zones B³, B²; C², C², C², correspond with
the sections or zones B³, B³. The first or upper sections or zones B' of
the retorts are designed as zones of preparation and desulphurization, in
which the ore is treated at a very low heat (a very dark cherry red) to
remove its water and sulphur and open its pores preparatory to its passing
to the next lower zones B².
When treating ores containing sulphur they (sections B¹) are con-
structed with air openings S, S, (Figure 10) at their bottoms, having
pipes or tubes leading to the outside of the furnace, through which cold
air may be admitted as desired. In connection with the air passages S
there are on top of the retorts small chimneys S¹ (Figure 10). By the

page_text: means described a sufficient quantity of cold air can be drawn into zones
B to create an oxidizing atmosphere therein when treating ores con-
taining sulphur. The second or middle sections or zones B2 of the retorts
are designed for reduction where the ore after having been treated in
zones B¹, B¹, is precipitated and there treated at a full cherry red heat a
sufficient time to eliminate the oxygen contained in it preparatory to its
passing to the next lower zones B³. The last-named lower sections or
zones of the retorts are designed for carbonization, where the ore passing
from the zones B2, B², is treated at a bright cherry red a sufficient time
to carbonize it to the desired extent. The horizontal flues C, C¹, and C²
communicate with the gas or distributing heat supply chamber G and
also with the main stack or chimneys L, L, and L. b, b', and 6ª are
dampers to regulate the draft and heat in said flues, and by which the
heat in each flue may be exactly regulated independently of the others;
a and a (Figure 10) are openings having dampers 68, 6, connecting
said flues C, C¹, and C³, with each other, by means of which the heat instead
of passing directly to the main stacks may be made to pass into the
flues C, C, to the flues O¹, 0¹, and C, C, and from thence to the stack L,
traversing in its passage the length of the flues C², C¹, and C. In this
manner the heat may be economised. F and F¹ (Figure 14) are hori-
zontal flues or chambers situated between the receiving chambers E, E,
and the transfer chambers E³, E³, and connected with the distributing
gas chamber G (Figure 10) and the stack L, and serve the double purpose
of conveying direct to the main stack any and all surplus heat not
required to heat the retorts B, B, B, and also to heat the transfer
chambers E2, E2, and the receiving chambers E, E. E², E³, are transfer
or discharging chambers situated underneath the retorts B, B, and over-
the main receiving chambers E and E, being separated from the retorts-
B, B, by the slides or dampers I, I, and from the receiving chambers E
and E by the slides or dampers I', I'. They are used for transferring-
the prepared ore from the retorts B, B, to the main receiving chambers
E, E. By their use the same amount of prepared orc can be removed.
from the retorts at each operation, which is essential to a uniform treat-
ment of all the ore. Each retort has one of these transfer chambers,
into which the ore when properly treated is first transferred; and from
thence to the main receiving chambers E and E underneath. The
capacity of each transfer chamber should be the same as the last section.
or zone of the retort. E, E, are main air-tight horizontal receiving
chambers situated underneath the discharging or transfer chambers

page_text: E, E³, into which the prepared ore is transferred or discharged from the
said chambers E³, E, and there retained until required by the forge fire
or puddling furnace attached thereto. The waste heat from the puddling
furnaces R is conveyed to the gas distributing chamber G in any suitable
way. T is an independent fire-place connected with the converting
furnace by the opening (Figure 12), laving the damper d. Said fire-
place may be used when it is desired to keep up the heat in the
converting furnace while one or both of the puddling furnaces are not
in operation.
In case a forge fire in lieu of a puddling furnace is to be combined
with the converting furnace the forge fire, or two or more of them as
required, can be arranged at the front of the converting furnace where
the fire-place T is represented. H and H' (Figure 14) are chambers
situated underneath the receiving chambers E and E, and serve to heat
said receiving chambers. They are connected with the flue F¹, from
which they receive heat. m, m³, m², m³, and mt, (Figures 10 and 12) are
doors corresponding with and leading into flues C, C, C², F and F', and
through which any and all ashes or emery collecting in said flues may
be removed. The retorts may be filled by means of a charger K, as
herein-before described.
In Figures 15 to 21 inclusive are represented furnaces adapted to treat
ore at different temperatures, as before specified, by direct contact or
action of the flame.
Figure 15 is a longitudinal vertical section of a furnace on line 1, 2,
Figure 17; Figure 16 is a like section on the line 3, 4, Figure 17;
Figure 17 is a plan view of the furnace; Figure 18 is a transverse
vertical section on line 5, 6, Figure 17; Figure 19 is a like section on
line 7, 8, Figure 17.
Figure 20 is a view of the tile sections, which are used in order to
gradually contract the carbonizing or lower ore chamber when used to
prepare the ore for steel.
Figure 21 is a longitudinal central section of a furnace combining the
improved converting apparatus with a puddling furnace instead of with
a forge fire, as shown in the preceding Figures.
There are three chambers B, B1, B2, in the first B of which the ore is
deprived of its moisture. and "slaked" so to speak, and if need be, de-

page_text: sulphurized. The flame in this chamber should be a dark cherry red.
If the ore is of such nature that it must be desulphurized cold air is
admitted to the chamber so as to create an oxidizing atmosphere therein
so long as needed, and during this desulphurizing operation the heat
must not rise above the fusing point of sulphuret of iron. . In the
second chamber B', to which the ore is transferred through slide door a
after treatment in the first chamber, the flame is maintained at a deep
full cherry red for the purpose of deoxidizing the orc. In the third
chamber B, if steel is to be made from the ore, the flame is maintained
at a bright cherry red, and the ore transferred through trap or door a
from the second chamber is subjected to this heat for time more or less
prolonged according to the degree of carbonization desired. If however
iron is to be made from the ore the heat in this third chamber should be
the same as that in the second.
When treating the ore for steel the third chamber is gradually con-
tracted by means of tile sections M, Figure 20, in the direction of the
end from which the flame escapes so as to concentrate the draft in tho
chamber and obtain a more powerful action of the flame on the ore, but
for making iron this contraction of the chamber is not necessary, and
the tile section need not be put in.
The ore is transferred from the lower chamber into the receiver A, onc.
of which is provided for each series of ore chambers. Beneath each
receiver is a main gas chamber C, in which the blast and products of
combustion are mingled so as to form a reducing flame; and leading
from each gas chamber is a main supply flue D (Figure 15), from which
the reducing flame is supplied to the ore chambers..
In order that the heat in each of the chambers. may be regulated
without interference with the heats in the others it is desirable that
while they are in communication, so that the flame may pass through-
each in succession, they shall at the same time have individual and.
distinct connections with the source of heat supply and with the stack,
so that the draft and heat in each may be regulated and controlled
independently of the others.
One arrangement of flues and dampers for this purpose is shown in
the Drawings.
The chamber B² opens into flue D at 6 (Figure 18), a damper & being
provided for this opening. Under ordinary conditions the heat should

page_text: not directly ascend higher in fluc D than chamber B2, and therefore in
flue D at that point is provided a damper c, as seen in Figure 18. By
closing this damper the flame will be forced to pass through chamber B³
in the direction of the arrow, Figure 16, thence passing out through the
open front end of the chamber it passes upward through the flue E,
which leads to the chimney stack, and which is provided with a
damper d, the closing of which causes the flame to enter the chamber B
through its flue opening e regulated by damper e¹. The flame passing
through this chamber in the direction of the arrow leaves it through the
flue opening f (Figure 18) regulated by damper f¹ and again. enters I
flue D, but at a point above damper c. The flame passing up through
the flue D enters chamber B through flue opening g regulated by
damper g¹, and traversing this chamber in the direction of the arrow.
leaves it through the flue opening & regulated by damper h¹ and escapes
into the chimney flue F. It will thus be seen that there is such com-
munication between the ore chambers that the flame may be caused to
pass continuously from one to the other in succession before escaping to
the chimney. The draft in the lower chamber can be regulated inde-
pendently of the others by either of the dampers c, d.
In order to give an independent supply of flame to the chamber B 2
there leads from the main flue D a branch flue D' (Figures 15 and 19)
governed by a damper i and opening into chamber B' near its front end,
as indicated in Figure 15; therefore the heat supply in this chamber is
obtained either from the lower chamber B³ or from the branch flue D¹..
or from both in conjunction. The draft in chamber B¹ is regulated 2
either by the dampers in chamber B¹ or by a damper ; in a waste
flue D connecting the upper end of the flue D with the chimney.
stack.
The top chamber B obtains its heat either from the lower chamber B'
or directly from the main gas chamber, this latter being effected by 3
opening damper c, which will permit heat to ascend flue D and pass
directly to chamber B. The draft and heat in this chamber are regulated
by its damper independently of the others.
E
From the main gas chamber C leads a waste fluc C¹ directly to the
chimney stack. This flue is provided with the proper damper, by which 3
it may be closed or opened at pleasure.
In the furnace, shewn in Figures 15-19 inclusive the converting
apparatus is heated by the forge fire G, which discharges its waste heat

page_text: in the gas chambers C. The front ends of the receiving retorts or
chambers A communicate with the forge fire, being closed by dampers
or slides K, which can be withdrawn whenever it is desired to obtain a
fresh charge of the prepared ore from the receiving chambers.
In Figure 21 the converting apparatus is represented as combined with
a puddling furnace H, one on each side of the furnace, and for cach
series of ore chambers. The receiving chamber has a sloping or funnel-
shaped bottom, at the lowest point of which is an air-tight inclined
chute I leading to the hearth of the furnace, and provided with a
discharge valve or damper 7. The flue J leads directly from the blast
chamber of the forge fire (Figures 15 and 16) to the chimney stack. It
is provided with a damper, and serves to regulate the temperature of the
blast chamber. The several orc chambers and the receiving chambers or
retorts are provided with doors of suitable construction, any one of which
can be opened whenever it becomes necessary to manipulate the ore in
the chamber to which the door belongs. The flues are also provided at
suitable points with doors through which access may be had to them for
the purpose of removing the ashes and emery and of cleaning them.
Above the upper chamber B is a hopper K¹ (provided with a suitable
door or damper), through which the ore is fed to the furnace. L is a
passage in the upper chamber B, through which, when necessary for
desulphurizing, cold air may be introduced into the upper chamber, so
as to maintain an oxidizing atmosphere therein. As soon as one chamber
is emptied it is again filled from the chamber above, so that the operation
may be made continuous.
In transferring the ore from one chamber to the other the draft
dampers in the chamber which is opened in order to permit the workman
to effect the transfer should be closed, so as to prevent possibility of
oxidizing action.
One, two, three, or more series of ore chambers may be combined in
onc furnace. Each series is entirely independent of the others, so that
the one may be used for steel while the other is used for iron.
In Figures 22 and 23 is represented a puddling or heating furnace,
designed to supply flux to be used to purify iron or steel during their
manipulation in said furnace, or to be used in the reheating of iron and

page_text: containing my improvements; Figure 23 is a longitudinal horizontal
section of the same.
A is the main hearth, constructed in any ordinary or suitable manner.
Beyond the main hearth, and between it and the chimney flue, is an
auxiliary hearth B, raised somewhat above the hearth A, and designed to
be used as the flux hearth for melting the flux which afterwards is used
in the main hearth. The two hearths are connected by a passage D,.
(Figure 23) preferably formed, as shown, in the side wall of the furnace,
so as to be in a measure shielded from the direct action of the heat.
This passage is provided with a valve or damper R, by which the
flow of flux from the upper to the lower hearth can be regulated at
pleasure.
Situated between the hearth A and the fire-place H is a gas chamber C,
in which are certain deflecting or obstructing walls F, F, F', which serve
to intercept the heat or flame in its passage from the fire to the hearth
of the furnace, and cause the gases of combustion to become thoroughly
mixed and united, and also prevent from passing to the hearth particles
of coal, which would injure the quality of the iron or steel. Over the
fire-place is located a chamber E, having in it a pipe or pipes T, which
may be used to heat the blast or to heat steam, the chamber being
perforated so as to admit heat from the fire to more direct contact with
the pipes. The superheated steam or heated air can be conveyed, as
shewn, through pipes T into the interior of the main central deflecting
or obstructing wall F, which for this purpose is made hollow, and is
provided on its rear face with discharge openings a, as seen in Figure 22,
through which steam or hot or cold air may be conveyed to and mixed
in the gas chamber with the gases from the fire. S, S¹, S², are doors in
the gas chamber, through which any coal or ashes accumulating in said
chamber may be removed. m, is the door in the flux hearth; m', the
door to the main hearth; and m² the door to the fire-place.
The furnace described can be used for manipulating iron and steel in
connection with the reducing furnace previously described, the flux in
hearth B being used to purify the metal during its manipulation, or the
furnace can be used in reheating iron and steel as follows:-Fire being
made in the fire-place H and the furnace being properly heated, the flux
to be used, which may consist of any substance that will produce a liquid,
cinder free from impuritics is charged into the flux hearth B.and after

page_text: being melted a sufficient quantity should be allowed to flow through
the passage D to the main hearth A to cover it about two inches deep.
This will depend however upon the size and dimensions of the iron or
steel to be heated. The iron or steel to be heated should then be
charged into the furnace and the operation conducted in the ordinary
manner.
The amount of melted flux that should be kept in the main hearth
will depend upon the size and character of the iron or steel to be heated.
The rule should be to use enough flux to cover about one-half of the
iron or steel; and by turning the iron or steel over one in a while as is
customary it will have a coating or covering of the melted flux to pro-
tect it from the blast. The quantity should also be regulated according
to the character of the iron or steel. If the iron is rough iron and
contains a large quantity of cinder it will not be necessary to use as
much flux as when the iron is of a more dry nature; and more flux
should be used for steel than for iron. The quantity used can be
regulated to suit the character of the metal operated on. The cinder
in the main hearth should be drawn off at the end of each heat, and.
fresh cinder transferred from the flux hearth to the main hearth. The
flux should be charged into the flux hearth from time to time, sufficient
to keep a certain amount of melted flux constantly on hand in the flux
hearth.
In purifying iron and steel the flux should be frequently drawn off.
and renewed in the main hearth; or a constant but small stream of flux
might be permitted to 'flow from the upper hearth to the lower onc, a
tap hole being provided for the latter through which the excess of flux
might escape, carrying with it the impurities.
"
In Figure 24-26 is represented an apparatus for making "steel
blooms direct from the orc. Figure 24 is a transverse section of the
furnace taken on the line x, x, Figure 25; Figure 25 is partly a sido
elevation and partly a section; Figure 26 is a longitudinal sectional
clevation taken on line y, y, of Figure 24.
A, A, are the walls of the furnace; B, the fire-place; C and O', flues
leading from the fire B to the ore chambers D, D', D³, and D³, and from
thence to stack E; F and F are retorts underneath the ore chamber Dª.
and D; G, G1, G2, and G', are dampers for regulating the heat in the
ore chambers D, D', D³, and D³; H and H' are hoppers through which.

page_text: .
the orc is charged into ore chambers D and D¹; I and I¹ are openings
(with covers) through which the ore is transferred from ore chamber D
and D¹ to ore chambers D2 and D³; 12 and I³ are openings through
which the orc is transferred from chambers D2 and D³ to retorts F
and F; J, J¹, are passages leading from presses L, L', to cooling
chambers J, J, into which the hot blooms may be transferred and
allowed to cool; K and K' are chambers into which the prepared sponge
is transferred from the retorts F, F¹, preparatory to its being introduced
into the presses L and L'; L and L' are presses or press chambers
where the hot sponge is pressed into blooms; 0, 0¹, and O2, arc doors
through which the operation of removing the sponge from the retorts F
and F to chambers K and K is conducted, or it may be conducted
through doors 0%, 0³; 0%, 0%, are doors to cooling chambers J, J;
0, 0%, are doors or openings through which the blooms may be taken
from the presses direct to the hammer or furnace; Q is a door opening
into flue C, C, for removing ashes, &c.; R and R' are doors opening into
ore chambers. D, D¹, D2, and D³, through which cool air may be admitted
when treating sulphur ores; S is a blast pipe for conveying wind to a
fire-place B; V is the follower of the press which comes in contact with
the sponge, it may be constructed same as V₁ so as to produce two
blooms at once; Z is an opening through which the sponge is transferred
from retort F to chamber K; Z' is a descending opening through, which
the
sponge is transferred to press L.
The operation of reducing the ore to sponge is conducted as follows:-
Fire is made in the fire-place B and the dampers G, G¹, G², G', opened.
When the ore chambers D and D₁ are heated to a cherry red they are
charged with ore to the depth of from four to six inches (the ore having
been previously reduced to about the size of walnuts and mixed with
proper fluxes and about an equal quantity in bulk of fine charcoal). After
the ore has been in chambers D and D¹about twelve hours it is transferred
through openings I and I¹ to ore chambers D2 and D³ directly under-
neath, where it is treated at a more intense heat for about twelve hours
more, after which it is transferred through openings 12 and 1³ to
retorts F and F¹, where it is treated from one to four days or longer,
according to the quality of the ore. The retorts may each contain two
or three charges.
The operation of reducing the prepared sponge to blooms is conducted

page_text: sufficient to remove all dampness and to heat the chambers L and K
throughout, after which the fire should be removed and all the openings
leading into the chambers L and K closed and made air tight by
plastering the edges. The damper 2 should then be raised and enough
of the prepared sponge transferred from retort F through opening Z to
chamber K to fill it. (The chamber K should be. of the same capacity
as the press chamber L). After the chamber K is full the damper 2
should be closed and the damper. 4 raised and the sponge allowed to
pass through the descending opening Z¹ to the press chamber L. When
it is transferred and the press chamber full the damper 4 should be
closed and the press follower B set in motion (by hand or machinery)
the sponge pressed into a bloom. While this is being done the
chamber K may again be filled with sponge ready for the next bloom.
When the bloom is made the side of the press chamber 5 may be raised
and the bloom transferred through the passage J' to cooling chamber J
and there allowed to cool before being removed, or it may be removed
through the door or opening. O direct to the hammer or furnace.
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 into effect, I would observe in conclusion that what I consider to
be novel and original and therefore claim as the Invention is, the
manufacture of iron and steel and in apparatus therefor, substantially as
and for the purposes herein-before described and illustrated in the
accompanying Drawings.
In witness whereof, I, this said John Henry Johnson, have to this
my Complete Specification set my hand and seal, this Twenty-
third day of May One thousand eight hundred and seventy-four.