IM- PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN FURNACES THEREFOR
Year: 1867

page_text: LETTERS PATENT to Samuel Dalton, of Chester, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN FURNACES
THEREFOR."
Sealed the 10th March 1868, and dated the 13th September 1867.
PROVISIONAL SPECIFICATION left by the said Samuel Dalton at the
Office of the Commissioners of Patents, with his Petition, on the
13th September 1867.
I, SAMUEL DALTON, of Chester, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, AND IN
FURNACES THEREFOR," to be as follows:-
I melt what is called pig iron as produced from the blast furnace, or the
same refined and known as plate metal, in a reverberatory furnace similar to
those commonly in use for puddling and boiling iron, or run the same in the
melted state from the blast furnace or refinery into such furnace, and add
thereto suitable quantities of fluxes of the kinds ordinarily used in the processes
known as "boiling" and "puddling," but in lieu of conducting the process as
in ordinary boiling or puddling to the making of "balls" or "blooms" I raise
the heat as the boiling ceases, and melt the iron and run it into ingot moulds
similar to those commonly used for making cast-steel ingots, instead of balling
it up, as commonly practised. If I wish to produce ingots of malleable iron
I use oxidizing fluxes (by preference hematite iron ore in powder) in sufficient

page_text: quantities to eliminate the carbon from the pig or plate metal under treatment
before running it into moulds. If I wish to produce steel I either use less of
the oxidizing fluxes, or by preference recarbonize the iron when brought to
the malleable state, as before described, by adding carbon to it (by preference
in the shape of pig iron containing carbon).
The furnace I construct in a manner similar to that usually adopted for
boiling and puddling iron, but by preference with a fire-place rather larger
than usual in proportion to the rest, and I line it with fire-clay or other fire-
resisting material, and construct the bed or floor hollow with a flue under it,
and apply heat to the under side of it by conducting the escaping gases along
it before discharging them into the chimney, or by adding a separate fire-place
and fire for the purpose to keep the bed or floor at the necessary temperature,
and I draw out the metal at a tapping hole similar to that commonly used in
ordinary puddling furnaces to draw out cinder, and placed at the most
convenient point for the purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Samuel Dalton in the Great Seal Patent Office on the
13th March 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
DALTON, of Chester, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of September, 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 me, the
said Samuel Dalton, Her special licence that I, the said Samnel Dalton, my
executors, administrators, and assigns, or such others as I, the said Samuel
Dalton, 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 IN THE MANUFACTURE
OF IRON AND STEEL, AND IN FURNACES THEREFOR," upon the condition (amongst
others) that I, the said Samuel Dalton, 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 same was to be performed, and cause the same to

page_text: 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 Samuel Dalton, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
I melt what is called pig iron as produced from the blast furnace, or the
same refined and known as plate metal, in a reverberatory furnace similar to
those commonly in use for puddling and boiling iron, or run the same in the
melted state from the blast furnace or refinery into such furnace, and add
thereto suitable quantities of fluxes of the kinds ordinarily used in the processes
known as "boiling" and "puddling," but in lieu of conducting the process as
in ordinary boiling or puddling to the making of "balls" or "blooms" I raise
the heat as the boiling ceases, and melt the iron and run it into ingot moulds
similar to those commonly used for making cast-steel ingots, instead of balling
it up, as commonly practised. If I wish to produce ingots of malleable iron
I use oxydising fluxes (by preference hematite iron ore in powder) in sufficient
quantities to eliminate the carbon from the pig or plate metal under treatment
before running it into moulds. If I wish to produce steel I either use less of
the oxidizing fluxes, or by preference recarbonize the iron when brought to
the malleable state, as before described, by adding carbon to it (by preference
in the shape of pig iron containing carbon).
The furnace I construct in a manner similar to that usually adopted for
boiling and puddling iron, but by preference with a fire-place rather larger
than usual in proportion to the rest, and I line it with fire-clay or other fire-
resisting material, and construct the bed or floor hollow with a flue under it,
and, apply heat to the under side of it by conducting the escaping gases along
it before discharging them into the chimney, or by adding a separate fire-place
and fire for the purpose to keep the bed or floor at the necessary temperature,
and I draw out the metal at a tapping hole similar to that commonly used in
ordinary puddling, furnaces to draw out cinder, and placed at the most
convenient point for the purpose.
The annexed Drawing shews a longitudinal section of such a furnace.
b
a, a, is the fire-place, which is arranged as is usual in puddling furnaces,
except that it is of larger size in relation to the bed; in the furnace repre-
sented in the Drawing the area of the fire-place is 17 square feet; 6 is the bed
of the furnace, having an area of 20 square feet; it is built of refractory fire-
bricks or lumps with a hollow c beneath it to form a flue, and the bed is

page_text: supported over the flue at short distances apart by fire-bricks set in the flue,
the arrangement being such that the draft in the flue can play all around
these fire-brick supports; d is a passage from the end of the flue c to the
chimney. The furnace is arched over at the top in the usual way, and is
cased and tied together by tie rods, as heretofore. The ash-pit of the fire-
place is enclosed and is supplied with blast of a pressure of, say, half a pound,
or one pound to the square inch, the blast enters the ash-pit through a nozzle
of, say, six inches diameter, a valve, however, is provided, by which the blast
may be moderated to any desired degree. Blast is also introduced at 'e in the
arch of the furnace immediately in front of the bridge, as shewn in the
Drawing; here a fire-brick lump is built into the arch, having in it a narrow
slit extending nearly from side to side of the furnace; the slit is not con-
tinuous, but is divided into three or other number of portions, so that the
block may not be unduly weakened by it. The total area of the slit may be,
say, 5 square inches, or the block has numerous small perforations in it.
The blast is communicated to the slit or perforations by a suitable casing on
the exterior of the furnace, and a valve is provided to regulate it; the blast
may be either cold or hot. The bed of the furnace is fettled with refractory
material. It will be observed that the variations which are made from the
ordinary puddling furnace admit of a much bigher beat being attained than is
practicable in such furnaces.
The following is the manner in which I prefer to operate:-I introduce the
pig iron or the refined cast iron into the furnace and treat it in a manner
similar to the puddling or boiling processes, using such fluxes as are commonly
employed, and working in a manner similar to that heretofore practised
(except in that I employ the blast) until the metal is in a state fit to ball or
make into blooms for shingling or rolling. In place of so doing, however, I
rapidly raise the temperature, and introduce into the furnace by means of a
ladle at the working hole a quantity of melted spiegel eisen, or of cold blast
hæmatite pig, or of other cast iron of good quality, and highly carbonaceous;
this I mix thoroughly with the contents of the furnace, and when the whole
is completely melted I tap it out into iron moulds through a tapping hole,
such as is now provided for tapping out the slag; in this way I obtain ingots
of cast steel, which may be rolled or otherwise worked. The proportion of
spiegel eisen or cast iron to be employed will vary according to the quality of
steel it is desired to obtain, as in producing steel on the Bessemer system by
the addition of spiegel eisen to decarbonized iron, a process which is now well
understood. It is not essential that the spiegel eisen should be added in a
melted state, it may be put cold into the furnace. Or in place of working

page_text: in the manner above described, if cast iron of very high quality be used, the
metal may be puddled or boiled in a similar way to that now practised in
making puddled steel, à process which leaves more carbon in the metal than
remains when wrought iron is made, and then when the metal is in a state fit
to be balled or made into blooms of puddled steel for shingling or rolling, in
place of so treating it the heat of the furnace is increased until the metal is
melted, and it is then tapped out into the moulds. Should it be desired to
obtain ingots of decarbonized iron from the furnace no spiegel eisen or cast
iron is added to the metal, but when it is ready to ball or make into blooms
the furnace is urged to the utmost, so that the metal may be thoroughly
melted, and it is tapped out as before. This however is a process which will
rarely be resorted to in practice, as the steely metal is more readily manu-
factured, and is in the present state of metallurgical knowledge more generally
useful.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that what I claim is,-
The treating iron in a manner similar to the puddling or boiling process
until it is in a state fit to be balled or made into blooms for shingling or
rolling, and then in place of so doing melting the metal and casting it into
moulds.
I also claim the adding spiegel eisen or other cast iron to the puddled or
boiled metal when it is in a state fit for balling or forming into blooms for
shingling or rolling, and when the mixture is thoroughly melted casting it
into moulds.
I also claim the constructing furnaces having flues under the working bed
in the manner herein-before set forth.
In witness whereof, I, the said Samuel Dalton, have hereunto set my
hand and seal, this Ninth day of March, in the year of our Lord One
thousand eight hundred and sixty-eight.
SAM". DALTON. (L.S.)