IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL, WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO OTHER PURPOSES
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by William Alexander Lyttle at the
Office of the Commissioners of Patents, with his Petition, on the
28th November 1874.
I, WILLIAM ALEXANDER LYTTLE, of the Grove, Hammersmith, in the
County of Middlesex, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL,
WHICH IMPROVEMENTS ARE PARTLY APPLICABLE TO OTHER PURPOSES," to be as
follows:-
I find as the result of private experiment not yet made public, that
when iron is smelted in accordance with any of the processes described
in the Specifications of my several Letters Patent of this year for various
improvements in the smelting of iron, the official numbers and dates of
which arc, 749, of 28th February last; 1096, of 30th March last; and
1560, of 4th May, the resulting metal possesses the extraordinary
property of being almost if not wholly free from any injurious impurity,
even when made from an ore hitherto deemed utterly useless through the
presence of silica or sulphur in excess for the smelting of iron. Also
that whereas only some peculiar ores will under the existing old process,

page_text: yield a metal suitable for the manufacture of steci direct from
iron; every known ore will do so if smelted under my plan.
The objects of this Invention are:-
סיP טuט
Firstly. To describe and secure specially for the making of steel, the
use of this now and hitherto unknown product of the above mentioned 5
Inventions, such Inventions having not yet been brought into use.
Secondly. To point out further means of ensuring that special purity
of pig iron above referred to, in accordance with those principles of
smelting which are the peculiar and essential features of the aforesaid
Patents.
Some of the apparatus which I shall have to describe as applicable to
the latter purpose will also be found to be applicable to other and
different purposes, but especially to the drying, or to the drying and
coking of artificial or moulded fuel.
t
1
When it is desired to dry the "artificial black band or triplex 1
compound" described in any of the aforesaid Patents, or any other
similar compound of crushed ore and carbonaceous matter, I make use
of the following modification of that well-known kiln designated
Hoffmann's Patent kiln for that purpose. This kiln will be constructed
in the same annular form adopted in the Hoffmann plan, but the several 2
chambers into which the ring of the kiln is divided will be provided with
a distinct licating arrangement attached externally to cach chamber as
herein-after described. The chambers moreover will only communicate
with each other by means of a flue running vertically from a point close
to the bottom of one chamber, and opening into the next adjoining 2
chamber near its roof, in order that the drying or coking heat may
have no escape from any chamber except by downward displacement into
the next.
A suitable air-tight valve will be provided so as to admit of the
communication between any two chambers by micans of the aforesaid a
fluc being wholly intercepted.
A circular hydraulic main or drain should pass underneath the
chambers, with an opening immediately below the bottom of the
aforesaid flue intercommunication, in order to receive any condensed
lianids which may be produced under the circumstances herein-after

page_text: this opening, and a metal or other plate should be set vertically across
the main or drain, completely closing its upper part to the depth of quite
two-thirds, and as the main would be kept at least half full of water, the
vertical plate would act as an intercepting diaphragm to prevent the
passage of air or gases. This main or drain should be set deeply so as
not to become much heated, and the opening into it should not be
large.
None of the openings provided in the Hoffmann's kiln for the intro-
duction of fuel from above into each chamber will be needed, and
instead of them the furnace belonging to each chamber may be set upon
the roof, if desired, with a downcast flue opening from the air-tight
ash-pit of each furnace, and terminated at the inner side of each arched
chamber roof. The draught by which these furnaces will be actuated
will be an exhausting draught acting through the circle of chambers,
and when the firo is alight it is evident that the gas produced by the
combustion will be free from uncombined oxygen, through the fact that
the air will have no entrance except down through the bed of red-hot
fuel in the furnace. In the centre of the ring of chambers will be
placed a powerful exhaust fan or other exhausting apparatus with its
supply pipe leading from a ring flue, which will run round all the
chambers, having an opening provided with a sluice or other valve into
the bottom of cach chamber. The discharge pipe will pass as a branch
of the aforesaid hydraulic main, or in any other convenient way, into a
gas-holder.
In order to describe the working of this kiln, I will take the chambers
to be of the same number as the letters of the alphabet, each letter being
taken to represent one particular chamber, and the chambers A and Z
being those which stand adjacent to each other as completing the ring.
Half the chambers, say A to M, are charged with lumps or bricks of the
conglomerate described in the aforesaid Patents, the carbonaceous matter
employed being bituminous coal or peat, or both peat and coal together,
and the doors at the outer ends or fronts of the chambers being built up
or shut, the furnaces of one or more of the chambers beginning at A are
lighted. The opening from the M chamber to N is shut, as must also
be all the suction openings leading to the exhausting apparatus except
that at M. The hot gases from the fire will then fill A and traverse the
whole series to M, going off there into the exhausting apparatus almost if
not quite cold. In a short time the whole contents of A, or A and B,

page_text: will be dry, or dry and coked, and then the port of communication
between B and C is shut, the fire now being lighted on chamber C alone
or with as many other chambers succeeding it as may be found necessary.
At the same time the port between M and N will be opened, and the
chambers N and O being then charged will be included in the drying
circle. The port between O and P will be shut, and the only exhaust
opening will be from P. In this manner the whole circle of the
chambers will be traversed continuously, one-half being always in action
whilst the other half will be devoted to the work of charging or
discharging the chambers.
The chambers A and B cannot be opened to the admission of air till
the contents are so far cooled down as not to endanger the ignition of the
carbon contained in each lump. Instead of having a separate furnace
for each chamber a circular tramway may be provided on the roof of the
chambers, and one or more traversing furnaces can be mounted thereon,
each of which on its removal into position above any particular
chamber may have its descending flue attached tightly to an opening
provided for that purpose in the top of each chamber. This opening
should be provided with an air-tight cap or lid, by which the opening can
be closed when the furnace is removed. By this means three important
stages of my new iron smelting processes aforesaid will be combined in
one, because,-

page_text: there will also be a valuable residuum of heavy hydrocarbon and
ammoniacal liquor in the hydraulic main.
Having by the foregoing plan rendered more complete and economical
my process of preparing the raw conglomerated material required
according to the aforesaid Letters Patent, I will now point out how the
new resultant pig iron will afford a ready means of producing steel at a
lower price than has ever before been attainable. If pig iron thus made
is melted or run molten from the smelting furnace into a Bessemer
converter, it can be converted into decarbonized iron by the blast in a
few minutes with hardly any of that loss of metal which now occurs, no
matter what may have been the nature of the ore from which it was
produced. The addition of spiegel cisen, in the present well-known way
of making Bessemer steel, to the decarbonized metal will complete the
production of steels of the finest quality for railway and all heavy uses.
A specially pure ore and a specially good fuel free from much sulphur
have hitherto been always used as essential to the success of the
Bessemer process, and these conditions have entailed a high cost, which
will be wholly at an end by the use of my new pig iron, because it will
always answer for making any kind of steel, irrespectively of the quality
of the ore and fuel used in its manufacture.
All the various well-known methods of making steel on the puddling
hearth or otherwise now practised, by acting upon molten pig metal
made from a specially selected description of ore, will also answer under
this Patent for utilizing my new kind of pig iron in the making of steel,
regardless always of the source or ore from which the new pig metal
came.
When it is desired to produce the purest tough malleable iron, this
can also be effected now with peculiar facility by running the new pig
into a Bessemer converter and blowing off the whole of its carbon.
Metal of this kind is however too soft for most uses, but the addition
thereto in the molten state of a suitable proportion of spiegel eisen or
other cast iron containing a definite per centage of carbon will impart
hardness in any desired degree up to the quality of cast steel, but in
order to ensure length of fibre in iron containing less than a steely per
centage of carbon, it is desirable to subject such iron to thorough rolling,
fagotting, and re-rolling, as at present pursued.

page_text: The kiln herein-before described will also furnish a valuable means of
drying, or of drying and coking, any powdered fuel, such as coal dust,
coke dust, peat, or other charcoal powder which may have been
consolidated into lumps as a fuel for smelting or other purposes, and
without the intermixture of ore, by means either of hydraulic lime, of u
cement, of plastic clay, or of raw wet peat, as specified in my several
Patents, numbered 749, 1096, and 1560, as aforesaid.
".