AN IMPROVEMENT IN THE MANUFACTURE OF IRON
Year: 1854

page_text: LETTERS PATENT to Patrick Moir Crane, of 18, Canonbury Villas; New
North Road, in the Parish of Saint Mary, Islington, in the County of
Middlesex, Gentleman, for the Invention of "AN IMPROVEMENT IN THE
MANUFACTURE OF IRON."
Sealed the 7th July 1854, and dated the 27th January 1854.
PROVISIONAL SPECIFICATION left by the said Patrick Moir Crane
at the Office of the Commissioners of Patents, with his Petition, on the
27th January 1854.
I, PATRICK MOIR CRANE, of 18, Canonbury Villas, New North Road, in the
Parish of Saint Mary, Islington, in the County of Middlesex, do hereby declare
the nature of the said Invention for "AN IMPROVEMENT IN THE MANUFACTURE
OF IRON," to be as follows:-.
In the process of obtaining iron from ironstone mine or ore in blast furnaces,
according to the ordinary mode in use in Great Britain and Ireland, certain
combustible gases are generated in the furnaces, which, on coming into contact
with atmospheric air, will ignite.
Now, the nature of, my Invention is to make use of these combustible gases
in smelting, and obtaining iron from ironstone mine or ore, by combining such
gases at or near the place where they are generated, either in the game or
adjoining furnaces, with a blast of hot or cold atmospheric air, thus producing
combustion of the gases, the heat arising from which combustion would be
applied to smelting the ironstone mine or ore.

page_text: SPECIFICATION in pursuance of the conditions, of the Letters Patent, filed
the. Great Seal Patent Office on
by the said Patrick Moir Crane
the 26th July 1854..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PATRICK
MOIR CRANE, of 18, Canonbury-Villas, New North -Road, in the Parish of
St. Mary, Islington, in the County of Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of January, in the year of our
Lord One thousand eight hundred and fifty-four, in the seventeenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Patrick Moir Crane, Her special licence that I, the said Patrick
Moir Crane, my executors, administrators, and assigns, or such others as
I, the said Patrick Moir Crane, 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 "AN. IM
PROVEMENT IN THE MANUFACTURE OF IRON," upon the condition (amongst others)
that I, the said Patrick Moir Crane, by an instrument in writing under my
hand. and seal, 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 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 Patrick Moir Crane, 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 two Sheets of Drawings, numbered
Sheet 1 and Sheet 2, hereunto annexed, and to the letters of referenco
marked on the diagrams, and denoting similar parts, where such parts can
be seen respectively.
Figure 1, Sheet 1, being a vertical section of a blast furnace (with my
improvements shewn thereon,) taken through the line l, m, at Figure 2; while
Figure 2, Sheet 2, is a horizontal section taken over the twyers; and Figure
3, also in Sheet 2, is an elevation of the front of the said blast furnace.
According to the ordinary practice of obtaining iron from ironstone mine or
ore in blast furnaces, certain combustible gases are produced, which usually

page_text: pass out at the top of the furnace and are lost in the atmosphere, or in some
instances such gases are collected and used for heating boilers for steam, for hot
blast stoves, or for other subsiduary purposes. Although the heating and com-
bustive powers of these gases are well known, chemists having estimated their
value when passing out at the top of the furnace at 70 to 80 per cent. of the
whole combustible'used, yet from difficulty in collecting them without deranging
the furnace, loss of heat in their passage, and other obstacles in practically
utilizing them, comparatively little has been done to achieve useful results.
The object of my Invention is to retain, combine, and use the gases produced
in blast furnaces during the process of smelting by intercepting them before
they lose their heat, and are so dispersed as to render it difficult to utilize
theim. This I effect by transmitting upon them, through blow-pipes, a blast of
common air, either heated or cold, so that the carbonic oxide and other gases
may, by their combination with the oxygen in the blast of air, become highly
heated; and thus combined; be forced upon the materials to be smelted in a
convenient manner; and thus be made useful in the smelting process in the
furnace.
My Invention, which is applicable to the present blast furnace, (as well as
furnaces to be constructed as herein-after directed,) and the means adopted
by me to adapt it thereto, will be found fully herein-after described. I do
not interfere with the, arrangements of the upper part of the blast furnace,
nor with operations carried on in that portion of it; but I alter that part
known by the name of the hearth. As is well known, the walls in blast fur-
naces at present in use are from the top of the hearth to the bottom thereof,
perpendicular on the four sides; and the materials are close pressed together,
when falling from the bosh to the bottom of the hearth, thus allowing no
opportunity; (from its being so closely filled, and from the manner in which the
walls are constructed,) of blowing upon and combining air with the gases as,
they rise from the twyre. Now, to avoid this difficulty; I make the back wall
of the hearth, or that opposite the fall of the furnace, as distinguished in the
section by that portion from a to b, sloping and extending out towards the
tymp or front of the furnace, and the wall opposite to it (which would usually
come within about 2 feet of the bottom of the hearth;) I partially remove, and
substitute an arch, as distinguished by the letters c and d. The object of this
alteration is to have a space above the twyers, where a blast of air can be com-
bined with the gases, and such gases, thus highly heated in their combination
with air, are thrown upon the materials to be smelted as they descend upon the
sloping walls of the hearth a to b, as well as making use of them by directing

page_text: them upon the lowest portion of the hearth. It will be seen that this arrange-
ment requires the side twyres to be shifted from the centre of the furnace (as
is usual) forward towards the front, as shewn in the horizontal section, Figure
2, Sheet 2. The arch c, d, is, for the better carrying out my improvement,
constructed of cast-iron beams or plates; but as the intense heat might melt
these beams or plates, I have arranged that water should circulate in some of
them, as is usual in water twyres, tymps, or blocks, and shewn at e, Figure 1;
Sheet I.
Having described the alteration in the hearth, I will now proceed to de-
scribe the blowing apparatus. The blast is to be raised by the means now
ordinarily in use, and may be either hot or cold, (but I prefer it heated,) this
being brought to the front of the furnace by pipes in the usual way; these pipes
carrying the blast are to be connected with the blow-pipes used and shewn at
f and g; sufficient apertures are left in the arch c, d, to admit of the elevation
and depression of these blow-pipes to all angles required, (as shewn for instance
at h and i,) and suitable mechanical arrangements are made for these changes
of position by having a vertical or inclined blast main, with sockets or otherwise,
or by any other suitable mechanical means, for the purpose of giving the said
elevations and dépressions. The tymp and dam plate are of the usual kind,
the tymp to be close to the level of the dam plate, as it is intended to work
with closed hearths. The twyres are the same as usual. The blow-pipes for
blowing upon the gas are to be of a smaller bore or diameter than those at the
twyre; and although eight are shewn in the Drawing, I wish it to be understood
that I in no way restrict myself to that number, as they may be increased or
diminished according to the requirements of the particular case under which
they are employed.
I will now proceed further to describe my improvement in the manufacture
of iron. I make an aperture or opening k, Figure 3, Sheet 2, in the arch c, d,
of an oblong or otherwise shaped orifice, with a lid to close it, for the purpose
of putting in any material which may be required in the hearth of the furnace.
In the blast furnace, as previously constructed, there is no means of adding
anything to the hearth, except under the tymp, which is usually filled with
iron and cinder, so that it cannot there be done; but as it is often desirable
to add materials of various kinds useful in iron smelting to the hearth, I
have arranged this communication with it, which will be useful in the
above as well as in manual operations connected with that portion of the
furnace. I also make the apertures in which the blow-pipes are inserted large
enough for bars or tools used by furnace keepers to be inserted when it may
:

page_text: be necessary for poking or stirring the materials in different parts of the
hearth, in order that they may be in the proper position for the blast.
:
I will now proceed to illustrate the "modus operandi" by which my improve-
ment is made useful. The furnace after being thoroughly heated is to be
charged in the usual manner with the well known proportions of coal, charcoal,
wood, peat, (charred or otherwise,) coke, anthracite, culm, ironstone, and iron
ore, limestone or other fluxes. When these charges have come down, the blast
is to be put on at the lower twyres, and as soon as the furnace is in working
order, the iron coming down freely and fluidly into the hearth, and the lower
part pretty well filled with the melted metal, the cinder also flowing at dam
plate, the blast may be put on through the blow-pipes in the arch c, d, which
will meet the gases produced at the twyers, and will cause them to impinge, in
the same manner as in the action of the common blow-pipe, a more intense
heat on the objects on which the flame of these gases is directed, and which
heat from being confined will spread around in that portion of the furnace.
When the furnace is thus in working order and the gases are being used, and
the iron is fluid and carbonated, the burden or charge of fuel can be altered
gradually so as to economise its use. The blow-pipes from their construction
(as already described) can be so elevated or depressed that they may be made
to blow on any portion of the hearth. The space between the tymp and dam
plate is to be closed in the usual manner, so as to prevent the loss of gas occa-
sioned by blowing forward, leaving only the cinder hole free. As the coal,
ironstone, and fluxes sometimes come down in a very irregular manner, and
often the hearth from this becomes cold, fills, and is what. is termed "gobbed,"
it is very desirable that a means of remedying this should exist. Now, by
the opening marked k, left for the purpose of adding materials to the hearth,
this can be done, as through it any thing deficient can be supplied to the
hearth.
Ilaving now described the nature of my Invention, and the means by which
it is carried into effect, I would here remark, that I have shewn and described
the best and most efficient means of practically working out such improvement,
but that I do not confine myself to the precise details herein made, or pro-
portions, or positions shewn in the Drawings, as variations may be made
therein and departures therefrom without at all departing from the principle of
my Invention; and, on the other hand, I lay no claim to the exclusive use of
any of the parts used in so effectuating my improvement, taken and considered
as parts, and not placed or used in combination and for the purposes of my
Invention of "An Improvement in the Manufacture of Iron," which I declare

page_text: to, be for, and I claim the production of, more thorough combustion of the
gases evolved in the blast furnace, and the use thereof in smelting iron by
combining them with blasts of hot or cold air issuing from blow-pipes
acting above the twyres, and in the manner and by the means herein-before
described.
In witness whereof, I, the said Patrick Moir Crane, have hereunto
affixed my hand and seal, this Twenty-sixth day of July, One thousand
eight hundred and fifty-four..
Witness,
EDWARD WATSON GEDGE,
Charles Street,
Somers Town.
P. MOIR CRANE. (LS.)