IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1877

page_text: LETTERS PATENT to Richard Howson, of Middlesborough-on-Tees, in the North
Riding of the County of York, Engineer, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF IRON AND STEEL."
Sealed the 29th September 1877, and dated the 25th July 1877.
PROVISIONAL SPECIFICATION left by the said Richard Howson at the
Office of the Commissioners of Patents on the 25th July 1877.
RICHARD HOWSON, of Middlesbrough-on-Tees, in the North Riding of the
County of York, Engineer. "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND
STEEL"
It relates to the process of puddling in revolving furnaces; and in carrying it out
I prefer to use the form or forms described by Samuel Godfrey and Richard Howson
in the Specifications of their Patents of December 20th, 1875, and January 29th,
1877, respectively, although other forms may be employed, provided they are furnished
with a ready means of cutting off and turning on the source of heat, and otherwise
regulating the relative quantities of gas and air passing over the charge.
In the ordinary process of puddling, as is well known, the charge is brought into
a state of violent ebullition owing to the escape of the gaseous constituents of the
pig iron among the fluid cinder.
By the method which I adopt there is in no case a great amount of boiling, and
there may be none at all.
The process is as follows:-Supposing the metal to be melted in the puddling
furnace itself. As soon as it is sufficiently liquid I add to the molten mass the
usual oxides, which are required for the conversion of the iron, in a dry, ground, or
powdered state.
These oxides may be combined with any of the well-known fluxes, and they
may be used either cold or hot, always provided that they are in the state of powder
or gravel, and not melted. The addition is best effected by slowly sprinkling into
the vessel containing the charge while it is revolving, by which means the oxides

page_text: become rolled up and thoroughly incorporated with the molten metal. The result
of this action is that the charge is considerably cooled down, becoming thick and
pasty, and the gases begin to escape without causing ebullition.
The revolution of the machine is now continued without the application of much
heat. The source of flame in fact may be entirely cut off, inasmuch as the metal
will become sufficiently hot of itself by the combustion of its impurities with the
oxygen supplied by the oxides. When a gaseous flame is urged by a blast of air,
as in the Godfrey and Howson furnace, the gas can in this case be conveniently shut
off, but it is not necessary to cut off the blast, as this to a certain extent may be
made to contribute to the refining action.
As the process goes on the iron will be observed to form itself into grains, without
ebullition, and this granulation proceeds until the whole is converted into wrought
iron. At the close of the operation it is desirable to increase the heat in order to
enable the converted iron to be balled up. For some purposes, however, the iron may
be removed from the furnace while still in a granulated state, or the grains may
even be melted so as to enable the metal to be poured out in a liquid state.
In those cases where the pig iron is not melted in the revolving furnace, but is
transferred to it directly from a blast furnace or from any other furnace in a molten
state, a similar method may be adopted, or the oxides may be put into the revolving
vessel before the metal is poured in.
The object in all cases is to incorporate the unmelted oxide with the melted metal.
My Invention may thus be briefly described as consisting of the amalgamation of
dry unmelted oxides with melted metal in the revolving furnace accompanied with
an intermittent flame.
By following out the above-described method of puddling I have discovered that
not only is violent ebullition avoided but the entire process is simplified, while the
resulting product is of good quality, adapted either for the ordinary subsequent
processes of manufacturing iron or for melting into cast steel, by either what is
known as the Attwood or the Siemens-Martin process.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard Howson in the Great Seal Patent Office on the 18th
January 1878.
RICHARD HOWSON, of Middlesborough-on-Tees, in the North Riding of the
County of York, Engineer. "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND
STEEL."
My Invention relates to the process of puddling in revolving furnaces; and in
carrying it out I prefer to use the form of furnace described by Samuel Godfrey
and myself in the Specification of our Patent of January 29th, 1877, No. 383, although
other forms may be employed, provided they are furnished with a ready means of
cutting off and turning on the source of heat, and otherwise regulating the relative
quantities of gas and air passing over the charge.
In the ordinary process of puddling, as is well known, the charge is brought into
a state of violent ebullition owing to the escape of the gaseous constituents of the
pig iron among the fluid cinder.
By the method which I adopt there is in no case a great amount of boiling; in
other words the charge may swell to a certain extent but without actual ebullition.
The process is as follows:-As soon as it is sufficiently liquid I add to the molten
mass the usual oxides which are required for the conversion of the iron in a dry,
ground, or powdered state.
These oxides may be combined with any of the well-known fluxes, and they may
be used either cold or hot, always provided that they are in the state of powder or
gravel, and not melted. The addition is best effected by slowly sprinkling into the
vessel containing the charge while it is revolving, by which means the oxides
become rolled up and thoroughly incorporated with the molten metal. The result of
this action is that the charge is considerably cooled down, becoming thick and pasty,
and the gases begin to escape without causing ebullition.
The revolution of the machine is now continued, but the application of much heat
is not desirable. The source of flame in fact may be entirely cut off, inasmuch as the
metal will become sufficiently hot of itself by the combustion of its impurities with
the oxygen supplied by the oxides. When a gaseous flame is urged by a blast of air,
as in the Godfrey and Howson furnace, the gas can in this case be conveniently shut
off, but it is not necessary to cut off the blast as this to a certain extent may be made
to contribute to the refining action.
As the process goes on the iron will be observed to form itself into grains, without
ebullition, and this granulation proceeds until the whole is converted into wrought
iron. At the close of the operation it is desirable to increase the heat in order to
enable the converted iron to be balled up. For some purposes, however, the iron may
be removed from the furnace while still in a granulated state, or the grains may be
melted so as to enable the metal to be poured out in a liquid state; or if the liquid
state be desired, the heat may be increased so as to prevent the formation of grains.
With respect to the melting of the pig iron, this may either be effected in the
revolving furnace itself or it may be directly transferred thereto from a blast furnace,
or intermediately from a cupola or other melting furnace. Moreover, the oxides,
instead of being sprinkled in after the revolving furnace is charged with metal, may
be introduced along with the metal or before the metal is charged.
The object in all cases is to incorporate the unmelted oxide with the melted metal.
My Invention may thus be briefly described as consisting of the amalgamation of
dry unmelted oxides with melted metal in the revolving furnaces accompanied with
an intermittent flame.
By following out the above-described method of puddling and refining, I have
discovered that not only is violent ebullition avoided, but the entire process is
simplified, while the resulting product is of good quality, adapted either for the
ordinary subsequent process of manufacturing iron or for melting into cast steel, by
either what is known as the Attwood or the Siemens-Martin process. It is also

page_text: partially applicable to the Bessemer process in the manner referred to by Samuel
Godfrey and myself in the Specification of our Patent of January 29th, 1877.
It will thus be understood that my Invention as above explained has two distinct
applications, viz., that of complete puddling, and that of incomplete puddling or
refining. In the one case wrought iron is produced containing little or no carbon,
and in the other case refined metal containing sufficient carbon to preserve fluidity
under a moderately high temperature. The completely puddled metal can either be
used as wrought iron or can be melted into steel by the addition of carboniferous pig
iron, as is well understood.
The partially puddled or refined metal can be converted into steel by the process
of decarburization. Both products also can to a certain extent be used in the
Bessemer process by transferring them as an addition to the ordinary charge of the
converter.
Having now described the nature of my said Invention and the manner of carrying
it into practical effect, I wish it to be understood that I am aware that oxides in a
dry state have been used in the ordinary puddling operation. They have been so
used in supplementary small quantities in the same manner as fluxes are usually
applied, and not as a principal agent, and in such a way as to avoid violent ebullition,
as is the case according to my Invention as above explained.
What I consider to be novel and original, and therefore claim as the Invention
secured to me by the Letters Patent herein-before first in part recited is, the use in
the processes of puddling and refining in revolving furnaces of dry oxides in
conjunction with intermittent flame, substantially as described.
In witness whereof, I, the said Richard Howson, have hereunto set my hand
and seal, this Sixteenth day of January, in the year of our Lord One
thousand eight hundred and seventy-eight.
RICHARD HOWSON. (L.S.)