AN IMPROVEMENT IN THE BLOWING PIPE OF BLAST FURNACES AND FORGES
Year: 1836

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ISAAC HAWKINS, of Chase Cottage, Pancras Vale, near Hampstead, in the
County of Middlesex, Civil Engineer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-eighth day of September, in the seventh year of
His reign, did, for Himself, His heirs and successors, give and grant unto me,
the said John Isaac Hawkins, His especial licence, full power, sole privilege
and authority, that I, the said John Isaac Hawkins, my exors, adiñors, and
assigns, or such others as I, the said John Isaac Hawkins, my exors, admors,
or assigns, should at any time agree with, and no others, from time to time
and at all times during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within England, Wales, and
the Town of Berwick-upon-Tweed, the Invention of "AN IMPROVEMENT IN THE
BLOWING PIPE OF BLAST FURNACES AND FORGES," communicated to me by John
Barker, a Foreigner residing at Baltimor, in the United States; in which said
Letters Patent is contained a proviso that I, the said John Isaac Hawkins,
shall cause a particular description of the nature of the said Invention, and
in what manner the same is to be performed, to be inrolled in His Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Isaac Hawkins, do hereby declare that the said Invention of an im-

page_text: provement in the Blowing Pipe of Blast Furnaces and Forges, as commu-
nicated to me by the said John Barker, and the manner in which the same is
to be carried into effect, are particularly set forth and described in the
following Specification or description thereof (that is to say):-
The improvement consists in so forming the mouth or mouths of the blowing
pipe as to deliver the usual supply of air into the furnace or forge in a thin
sheet or in thin sheets, possessing great surface in proportion to the bulk or
volume of the stream of air, in order that the air may impinge upon impart
its oxygen immediately into a large quantity of the ignited fuel, the more
advantageously to promote combustion, and also to avoid the comparatively
chilling effect which is produced by the pouring in of cold air in a body of
considerable thickness, as is the case in the ordinary way of delivering it
through a circular orifice, or through two, three, or even four circular orifices.
In carrying this improvement into effect, I sometimes enlarge the common
circular orifice of the mouthpiece or extremity of the blowing pipe next to
the fire to three or more times the usual diameter, and place a conical plug
concentrically within the same, with the apex of the cone pointing towards the
bellows or blowing machine, and the base of the cone lying even with the end
of the mouthpiece towards the fire, or lying a little within or a little without
the end of the mouthpiece, the dimensions of the base of the cone being such
as shall leave an annular aperture or air passage between the cone and the
pipe equal in area to the area of the ordinary mouthpiece, or to the conjoint
areas of both or of. all the mouthpieces when two or more are used. By this
arrangement the air is delivered in such a thin cylindrical sheet that its con-
tained oxygen will find immediate access to the ignited fuel, and augment the
intensity of the heat more advantageously than can be effected by a thick
stream of cold air, or by two, three, or four such streams, and I support and
retain the cone in its place within the pipe or mouthpiece by means of two
pins or bars passed horizontally through the sides of the pipe and through the
sides of the cone, and the pins or bars crossing at right angles the common
axis of the cone and of the pipe; and I also place lateral guides to assist in
keeping the cone concentric with the pipe, and I sometimes elongate the two
holes in the cone, so that the cone may slide a short distance across the pins in
the line of the common axis of the cone and of the pipe upon being moved
by a lever having its fulcrum in or near the side of the pipe, one arm of the
lever projecting outwards from the pipe, to which arm the power may be
applied, and the other arm within the pipe reaching to the apex of the
cone, where it takes hold of a link affixed in any common manner to the apex
of the cone. The lever, on being moved on its fulcrum by its outer arm

page_text: lengthwise of the pipe, will cause the inner arm to move the cone in the line
of the common axis of the cone and of the pipe; and I sometimes make the
extremity of the mouth piece surrounding the base of the cone a little
conical, enlarging outwards towards the fire, whereby the sliding of the cone in
the common axis will enlarge or diminish the area of the annular aperture,
according as the sliding cone is carried towards or from the fire. And I some-
times carry the Invention into effect by making the blowing pipe with two or
more branches, each branch terminating in a mouthpiece having a long
narrow orifice delivering the air into the furnace or forge in a thin broad sheet,
the conjoint areas of all the oblong orifices being equal to the area of the
single circular orifice as commonly used. And in the case of a blast furnace,
whether of the larger kind for smelting of iron, or of the smaller kind called
a cupula, in which cast iron is melted, I distribute the mouth pieces around
the furnace so as to deliver the thin broad sheets of air into the fire at nearly
equal distances. And in the case of a forge I distribute the mouthpieces at
equal distances along the fire according to the length required to be heated,
and I place the greatest dimensions of the orifices vertically, and make them
of such a height as shall the most effectually blow up the fire of the altitude
required. And I sometimes make use of five or more mouthpieces with
circular orifices; but although they are much superior to a less number, I do
not deem them so advantageous as the oblong form herein-before described.
And I declare that I lay no claim to the mode herein-before described of
sliding the cone within the mouthpiece, nor to the application of two, three,
or four mouthpieces with circular orifices. But I do claim as the Invention
communicated to me as aforesaid the enlarged mouthpiece within which is
placed concentrically a conical plug of such dimensions at the base as shall
leave an annular aperture for delivering the air into the fire in a thin cylin-
drical or conical sheet, as herein-before particularly described; and I also claim
the application of two or more mouthpieces with oblong orifices for delivering
the air into the furnace or forge in thin and broad sheets. And, finally, I
claim the application of five or more mouthpieces with circular orifices for the
purpose of greatly increasing the surface of the stream of air in comparison
with its volume.
In witness whereof, I, the said John Isaac Hawkins, have hereunto set
my hand and seal, this Twenty-second day of March, in the year of
our Lord One thousand eight hundred and thirty-seven.
JOHN ISAAC (L.S.) HAWKINS.

page_text: AND BE IT REMEMBERED, that on the Twenty second day of March,
in the year of our Lord 1837, the aforesaid John Isaac Hawkins came before
our said Lord the King in His Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Inrolled the Twenty-eighth day of March, in the year of our Lord One