IMPROVEMENTS IN THE MANUFACTURE OF IRON
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BENJAMIN
THOMPSON, of Newcastle-upon-Tyne, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the First day of August, in the
thirteenth year of Her reign, did give and grant unto me, the said Benjamin
Thompson, my exors, adiñors, and assigns, Her especial licence, full power,
sole privilege and authority, that I, the said Benjamin Thompson, my
exors, admors, and assigns, and such others as I, the said Benjamin Thompson,
my exors, admors, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend my
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF IRON," within that part
of Her said Majesty's United Kingdom of Great Britain and Ireland called
England, Her Dominion of Wales, and Town of Berwick-upon-Tweed; in
which said Letters Patent there is contained a proviso requiring that I,
the said Benjamin Thompson, should particularly describe and ascertain the
nature of my said Invention, and in what manner the same is to be per-
formed, by an instrument in writing under my hand and seal, and cause the
same to be enrolled in Her said 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, reference being. thereunto had, will more fully and
at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Benjamin Thompson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are particularly
described and set forth in and by the present Specification, reference being had
to the accompanying Drawing hereunto belonging, that is to say:-
My Invention consists,―
Firstly, in the introduction into blast furnaces of the air necessary to com-
bustion by withdrawing the gases from the body of the furnace by means of
exhaustion, or, in other words, in producing the necessary current of air by
indraught instead of by the ordinary method of injection. And,
Secondly, in a mode of producing the advantageous employment of such of
the gaseous products of the blast furnace as are adapted for the purpose of
combustion in another furnace or other furnaces, by means of a jet of steam or
other method of exhaustion.
And, in order to explain the manner in which the first division of my
said Invention is to be put in operation, I will now proceed to the description
of the Drawing, which represents, on a scale of about three twentieths of an
inch to the foot, several views of a blast furnace constructed accordingly.
Figure 1 is an external elevation; Figure 2, a plan; Figure 3, a vertical
section through the dotted line Z, Z, in the plan; and Figure 4, a horizontal
section through the dotted line Y, Y, in the elevation. a marks the hearth of
the furnace; b, the boshes; c, the body; d, a domie; e, the throat, furnished
with a lid or cover f; g is a tunnel or gallery, constructed in the solid masonry
around the throat, to receive the gases through twenty-eight vents (more or
fewer), of about eight inches by four inches each, placed in a circle below the
top of the dome; h, h, two elbow exhausting pipes (about eighteen inches
<liameter),, inserted into the gallery on opposite sides of the furnace; i, i, two
other pipes, four or five inches diameter, passed up within the larger ones, and
extending down to a boiler at the back of the structure for supplying steam to
eight jets (more or fewer) on the top of each. These jets are fitted severally
with separate small branches, the orifices of which are one sixteenth of an
inch (which may be more or less), and each set of branches is disposed in a
circle or other manner adapted to produce the fullest effect in promoting
exhaustion in the large pipes. The situation of the tuyres is marked by the
letters k, k, and their number six (though more or less may be used), and each
of them will hold its blow pipe, whether the air introduced be cold or heated,
fire clay being well pressed around them when working the furnace. The two
steam pipes unite and communicate singly with a boiler, a valve or cock being
placed in the single portion for regulating the quantity of steam to be dis-

page_text: charged; and within the boiler, and at the mouth of the steam pipe, there is
another valve, for the purpose of shutting off and turning on the steam by
means of a rod communicating with both the top and the bottom of the
furnace. The exposed pipes should be clothed with some good non-conductor
of heat. I consider an exhaustion, corresponding to an inch and a half of
mercury, or three quarters of a pound on the square inch. (though I do not
limit myself), fully adequate to the proper working of the furnace. To prevent
any inlet of air, except at the tuyeres, the iron lid f is fitted to a metal ring,
with a rib on its inner edge, the face of which, and the corresponding under
part of the lid, should be ground or turned, and truly fitted to each other. The
lid may be lifted either by a hand-over-hand pull, or by a light windlass, being
so far balanced by a counterpoise weight as to leave only a sufficient prepon-
derance to secure an effectual pressure on its seat. When raised to a suitable
height, which may be three and a half or four feet, there should be arranged
in readiness not fewer than four complete charges of fuel, ore and lime to be
put on at one time, that these stoppages (for the jets must be laid off the while),
may not occur more frequently than can be helped. I would here remark,
that as it constitutes no portion of my Invention, I have considered it unneces-
sary to represent in the Drawing the layers of the several different materials
with which the furnace is lined, my furnace in this respect being constructed in
the ordinary manner.
Another method of producing the required exhaustion is by means of
a lofty chimney, and although this may be too expensive in the first outlay
for the working of one or even two furnaces, I have no doubt that the
economy of working will recommend it when there are more than two
furnaces in proximity to each other. The exhausting pipes in this instance
would have to be curved to the back of the furnace, united there, and then
run direct to the chimney, for the purpose of closing the communication
therewith, a valve on the plan of Watt's throttle valve might be placed in
the single pipe. This would be the only necessary variation from the already-
described scheme of the steam jets:
In place of either of the former plans, the Archimedean screw, another
power of great force in the draught of gaseous fluids, might be readily applied
by insertion into a single pipe uniting the two separate exhausting ones h, h.
I would here remark, than an old furnace may be adapted to my Invention
by taking some eight feet off its top, and building it up again conformably.
I will now proceed particularly to explain the manner in which the second
division of my said Invention is to be put in operation. To effect the object
before mentioned I. make the exhaust pipes h, h, without steam pipes, enclosed,

page_text: to form part of a train of tubing leading to the air-heating stoves, steam-
boiler furnaces, or other furnaces in which it may be desired to employ the
gases arising from the blast furnace; and it will generally be found more
convenient that the exhaust pipes should branch off from the said furnace in
the manner represented by the dotted lines in the Figure 3. And further
than this (which arrangement of itself I disclaim, as having been before
published), in. addition thereto, and in combination therewith, I employ a jet
or jets of steam in the chimnies or flues leading from the furnaces or stoves
into which the said gases have been introduced. The requisite equivalent of
atmospheric air will have to be admitted to furnaces or stoves (in which the
gases are employed) in the ordinary manner, which, being well known, I
consider it unnecessary to describe. But I would remark, that they may be
employed in one furnace or stove, or in several, either consecutively or sepa-
rately, the steam jet or jets in the last case being applied in one main chimney
or flue uniting those from the several furnaces or stoves. I would also here
disclaim the use of steam jets for the purposes of exhaustion, except in so far
as the same may be employed in the manner and for the purposes above set
forth and described.
In witness whereof, I, the said Benjamin Thompson, have hereunto set
my hand and seal, this Twenty-sixth day of January, in the year of our
Lord One thousand eight hundred and fifty