IMPROVEMENTS IN SMELTING OR REDUCING FURNACES, AND IN THE MANUFACTURE OF IRON
Year: 1873

page_text: LETTERS PATENT to Edwin Pettitt, of Birmingham, in the County
of Warwick, Civil Engineer, for the Invention of "IMPROVEMENTS
IN SMELTING OR REDUCING FURNACES, AND IN THE MANUFACTURE OF
IRON."
Sealed the 15th May 1874, and dated the 19th November 1873.
PROVISIONAL SPECIFICATION left by the said Edwin Pettitt at the
Office of the Commissioners of Patents, with his Petition, on the
19th November 1873.
I, EDWIN PETTITT, of Birmingham, in the County of Warwick,
Civil Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SMELTING OR REDUCING FURNACES, AND IN THE MANUFACTURE
Or IRON," to be as follows:-
My improvements consist in the construction of a new form of
smelting or blast furnace or series of furnaces in which the ores of
iron or other metal may be reduced, and the resulting metal purified
and rendered of any desired quality while in a fluid or semi-fluid
state.

page_text: I construct a horizontal arched chamber having inclined cheeks and
a longitudinal hearth or channel running the whole length, or nearly so,
of the chamber (a cross section of which chamber taken through the
tuyeres would be similar to the cross section of the ordinary blast furnace
now in use, with the exception of the roof which is sprung from the
boshes or inclined cheeks). At certain distances apart I place tuyeres
for the purpose of applying the blast to the ores, fluxes, and fuel, to
cause their reduction.
In the roof of the chamber I construct two, three, five, or more
openings through which the fuel, fluxes, and ores, are fed into the
chamber.
At one end of the chamber I construct a shaft or chimney of
sufficient height and capacity, into which the interior of the chamber
has an opening.
At the other end of the chamber I construct a hearth or receptacle to
receive the iron and slag flowing into it through the longitudinal hearth
or channel before-mentioned, where the molten products of the furnace
or series of zones of fusion may be heated and purified and from whence
they may be run off in the usual manner.
The ores, fluxes, and fuel fed into the openings in the roof of the 2
furnace, which for convenience I will call the "trunnel feed hole," may
be all of the same kind and quality, or they may be varied. One
trunnel may be fed with ore, flux, and coke, another with ore, flux, and
anthracite, another with ore, flux, and bituminous coal, or other available
fuel, and these various products flowing through the longitudinal hearth 2
or channel into the receiving hearth may there be further worked and
finished to the desired quality.
If the ores, fluxes, and fuel are of a like kind the product in the
hearth will be an average quality of metal produced by the series of
working points of the chamber.
If the ores, fluxes, and fuel are varied the product will be of a
quality partaking of the nature of iron or steel, as may be desired.
3
Another modification of the serial furnace is the substitution of air
holes instead of blast applied by the usual machinery. In this case, the
draught of the stack or chimney causes the air either hot or cold to be 3
drawn into the furnaces with all the force of a blast.

page_text: If it is desired to produce several distinct classes of metal, then I
dispense with the longitudinal hearth or channel and the receiving
hearth, and construct a separate hearth for each zone or trunnel, and
run off the products in the usual way.
.
The furnace when in work will be dominated by the stack or shaft,
the draught of which may be increased or lessened by opening or
partially closing with dampers the progress of the heated gases from the
chamber, and as they pass from one zone into, around, and through
other zones in succession great economy of fuel and a largely increased
production will result.
The improvements in the manufacture of iron consist in giving
different supplies of ores, fluxes, coke, anthracite, or other fuel to several
zones or trunnels, as herein-before explained, and in allowing the
products from the several zones or trunnels to flow into a common
receiving hearth, whereby I am able to vary as required the quality or
nature of the iron obtained.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edwin Pettitt in the Great Seal Patent Office on
the 19th May 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWIN
PETTITT, of Birmingham, in the County of Warwick, Civil Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of November, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Edwin Pettitt, Her special licence
that I, the said Edwin Pettitt, my executors, administrators, and
assigns, or such others as I, the said Edwin Pettitt, my executors,
administrators, and 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 Invention for "IMPROVEMENTS

page_text: IN SMELTING OR REDUCING FURNACES, AND IN THE MANUFACTURE OF IRON," upon
the condition (amongst others) that I, the said Edwin Pettitt, my
executors or administrators, by an instrument in writing, under my, 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 5
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 Edwin Pettitt, do hereby declare
the nature of my said Invention, and in what manner the same is to be 10
performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the accompanying
Drawings, that is to say:-
My improvements consist in the construction of a new form of
smelting or blast furnace or series of furnaces, in which the ores of 18
iron or other metal may be reduced and the resulting metal purified
and rendered of any desired quality while in a fluid or semi-fluid
state.
I construct a horizontal arched chamber having inclined cheeks and
a longitudinal hearth or channel running the whole length or nearly so 20
of the chamber, a cross section of which chamber taken through the
tuyeres, would be similar to the cross section of the ordinary blast
furnace now in use with the exception of the roof which is sprung like
an arch or dome from the boshes or inclined cheeks. At certain
distances apart I place tuyeres, for the purpose of applying the blast to 2
the ores, fluxes, and fuel, to cause their reduction.
In the roof of the chamber I construct two, three, five, or more
openings, through which the fuel, fluxes, and ores are fed into the
chamber.
At one end of the chamber I construct a shaft or chimney, of 3
sufficient height and capacity, into which the interior of the chamber
has an opening.
At the other end or at the centre or other convenient part of the
chamber, I construct a hearth or receptacle to receive the iron and
slag flowing into it through the longitudinal hearth or channel before 3
mentioned, where the molten products of the furnace may be treated

page_text: and purified, and from whence they may be run off in the usual
manner.
The ores, fluxes, and fuel fed into the openings in the roof of the
furnace, which for convenience I will call the “trunnel feed holes," may
be all of the same kind and quality or they may be varied. One
trunnel may be fed with ore, flux, and coke, another with ore, flux, and
anthracite, another with ore, flux, and bituminous coal, or other
available fuel; and these various products flowing through the longi-
tudinal hearth or channel into the receiving hearth, may there be
further worked and finished to the desired quality.
If the ores, fluxes, and fuel are of a like kind, the product in the
hearth will be an average quality of metal produced by the series of
working points of the chamber.
If the ores, fluxes and fuel are varied the product will be of a
quality partaking of the nature of iron or steel, as may be desired,
according to the nature of the materials under operation.
Another modification of the serial furnace is the substitution of air
holes instead of blast applied by the usual machinery. In this case the
draught of the stack or chimney causes the air either hot or cold to be
drawn into the furnaces with all the force of a blast.
If it is desired to produce several distinct classes of metal, then I
dispense with the longitudinal hearth or channel and the receiving
hearth and construct a separate hearth for each zone or trunnel, and run
off the products in the usual way.
The furnace when in work will be dominated by the stack or shaft,
the draught of which may be increased or lessened by opening or
partially closing it with a damper. Thus the velocity of the heated gases
through the chamber will be regulated and under control; and as
these pass from one zone into, around, and through other zones in
succession, great economy of fuel and a largely increased production will
result.
The mode of construction of the furnace with an arch or dome
springing from the boshes or inclined cheeks as herein-before described,
is applicable to smelting or reducing furnaces, whether to be used in a
series or singly.

page_text: My improvements in the manufacture of iron consist in giving
different supplies of ores, fluxes, coke, anthracite, or other fuel, to
several zones or trunnels as herein-before explained, and in allowing the
products from the several zones or trunnels to flow into a common
receiving hearth, whereby I am able to vary as required the quality or
nature of the iron obtained.
Figure 1 of the accompanying Drawings is a cross section, Figure 2
a longitudinal section and part side elevation, and Figure 3 a ground
plan, taken at the tuyeres of a serial furnace, constructed according to
my Invention.
A, A, A, are the trunnels or feed holes into which the materials to
be operated upon are thrown in the usual manner; B, B, B, is the
hearth or longitudinal channel where the fused metal and earthy
matters gather from all parts of the furnace and flow into the working
hearth C, C; E, E, E, are the tuyeres for the application of the blast;
F, F, are the working arches; G, G, the tuyere arches. The hearth B
is slightly inclined in the direction of the working hearth C, so as to allow
the molten products to flow freely forward. The incandescent gases
however are drawn in a horizontal direction by the action of the shaft D,
as shewn by the arrows. There is also a slight indraught of cold air
at the trunnels, which keeps the top of the furnace beneficially cool.
The velocity of the gases and other products is regulated by a damper in
the shaft D.
The serial furnace, upward to the top of the boshes, is in cross section
identical with that of the ordinary blast furnace, but from the top of
the boshes an arch or dome forming a roof is sprung. The section is
continued the whole length of the furnace except at the working
hearth C, which may be constructed either in the centre or at either
end of the furnace, as convenience may dictate.
When in blast the gases pass through and around each successive
mass of material, and exhaust themselves of all value before being per-
mitted to escape at the shaft, take for instance zone No. 1, and give it
the ordinary proportion of fuel, the waste gases help the operation of
zone No. 2, which will therefore require less fuel than No. 1, No. 8 still
less than No. 2, and so on through the series.
The tuyeres or air holes E, E, may be placed at any desired distance
apart the whole length of each side of the furnace. In the case of no

page_text: blast being used, the nearer these are placed together the greater the
supply of hot or cold air drawn into the furnace by the shaft, and
two and even three rows of air holes may be found useful with a
sufficient shaft.
The receiving hearth C may as before stated be placed either at the end
of the furnace or in the centre or even at the bottom of the shaft itself.
It should be constructed of the best materials and with the best workman-
ship in every respect, as applied to the construction of the ordinary blast
furnace. The hearth itself may be said to be a reservoir for the
O collection of products from all the working zones; it is provided with
several openings into the hearth to facilitate the working and treatment
of the metal for the purpose of refining it before it is run off.
Figure 4 is a longitudinal section of a furnace in which no receiving
hearth is required, each zone of action being by means of dam stones or
3 bridges X, X, made distinct from the others, so far as its product is
concerned, and forming a separate furnace.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim as my
improvements in smelting or reducing furnaces,-
1st. Constructing smelting or reducing furnaces as herein-before
described.
2nd. A longitudinal chamber or furnace, in the roof of which are two
or more openings or feed holes at certain distances apart into which the
materials are thrown for reduction, and with a longitudinal hearth or
channel to conduct the molten materials to a receiving hearth, and a
shaft of sufficient capacity and height to dominate the draught of
such chamber or furnace and cause the heated gases and products of
combustion to pass horizontally through such chamber, substantially as
herein-before described.
3rd. The arrangement by which each working zone of a serial furnace
acts as a separate furnace, in so far as the separation of its product is
kept distinct from products of the other zones, substantially as herein*
before described.
4th. The construction of furnaces with an arch or dome springing
from the top of the boshes, substantially as herein-before described.

page_text: And I claim as my improvements in the manufacture of iron the
charging of several zones or trunnels of a serial furnace with different or
varying supplies of ores, fluxes, and fuel, and allowing the products of
the said several zones or trunnels to flow into a common receiving
hearth, as herein-before explained.
In witness whereof, I, the said Edwin Pettitt, have hereunto set
my hand and seal, this Eighteenth day of May, One thousand
eight hundred and seventy-four.