Improvements in and Apparatus for the Production of Steel for Steel Castings, also Applicable for Melting Copper, Tin, and other Metals.
Year: 1886

page_text: Date of Application, 16th Dec., 1886.
Specification Accepted, 22nd Feb., 1887.
COMPLETE SPECIFICATION.
Improvements in and Apparatus for the Production of Steel for
Steel Castings, also Applicable for Melting Copper, Tin, and
other Metals.
We JOSEPH ELTON BOTT of 240 Cornwall Terrace Levenshulme near Manchester
Steel Founder, SAMUEL JOHN HACKNEY of Boothroyden Rhodes near Manchester
Steel Founder and WILLIAM CRAVEN of Smedley House Cheetham near Manchester
Engineer, all in the County of Lancaster do hereby declare the nature of our invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statenient :-
Heretofore steel castings have generally been produced from metal, (1) melted in
crucibles, (2) on the bed of a Siemen's furnace or (3) from molten metal converted
in a Besseiner vessel.
It is well known that good steel castings can be produced by the crucible process
but owing to the breaking of pots the objectionable (sometimes dangerous) necessity of
handling a multiplicity of crucibles and the variation of the metal contained therein,
the crucible process is generally a most unsatisfactory one.
The Siemens or open-hearth process requires a very costly plant, is not suitable for
the production of small and intricate steel castings besides requiring to be kept in
constant operation whether the production be large or small.
The Bessemer process requires expensive Blowing Engines and apparatus and is
subject to the disadvantage of its being necessary to empty the converting vessel of
its finished charge very quickly whether the moulds for the castings to be made are
ready or not and it is therefore of little uso except where the whole of a charge can be
immediately poured into one mould.
The object of our invention is to produce (quickly and cheaply) molten steel without
the necessity of erecting a costly plant and to admit of the use in large quantities of
scrap wrought iron and scrap steel and of the same being directly converted into
molten steel suitable for pouring into the smallest and most intricate mould, the
temper or percentage of carbon and other elements in the resultant casting being
regulated at will by the operator.
In carrying out our invention we avail ourselves of the principle that carbon in a

page_text: natural or artificial state of denseness or compression offers a great resistance to
combustion except terminally or superficially but when in a state of combustion in the
presence of oxygen the most intense heat is evolved, carbonic acid being slowly formed,
advantage being taken of this feature in electric lighting viz in the use of carbon
poles or candles of electric arc-lights in which intense combustion takes place at the
points only.
Now the electric current being capable of producing intense terminal combustion of
carbon poles, advantage has been taken of this feature for fusing refractory metals and
metalloids by means of powerful dynamos but we produce an almost equivalent
temperature from carbon without the aid of expensive electrical currents and as
hereinafter described.
We find that by first heating carbon blocks or pieces to a red heat in or by a
suitable heating apparatus and then applying a powerful blast of air we obtain a
similar action to that of the electric current but instead of the heat generated being
local the incandescence under atmospheric pressure becomes superficial and general,
the carbon gradually wasting over all its surfaces instead of becoming (as is the case
with coke charcoal coal and ordinary carbonaceous matters) porous and burning
en-masse.
On the accompanying drawing we illustrate in section (Fig. 1.) the furnace and
apparatus we prefer in carrying out our invention.
al
The furnace A. consists of a suitable shell or casing A¹ preferably of metal having
refractory lining B. and surrounded at the lower portion by an air belt or blast
chamber C. (which is supplied with blast from a Fan or Rotary Blower) and all
supported upon the base or foundation plate M. Tuyeres D. and E. connect the
blast chamber C. with the interior of the furnace. Below the blast chamber C. are
two openings, one F. connecting with the auxiliary furnace G. the other H. forming a
channel or outlet to a receiver or ladle I. also lined with refractory material J. (The
lining may be hollow all round as shewn at S. and the space S. filled with pre-heated
carbon and an air blast supplied through the pipe T. for the purpose of retaining
masses of metal in a molten state for a considerable time)-The tapping hole K. being
placed at the lower portion of same. The base M. of the furnace is supported on
pillars L. L. and a tapping hole N. is provided for running off the slag produced
during melting and converting operations.
The top of the furnace is provided with a hinged cover O. having an outlet P. to
allow of the escape of the surplus products of combustion and such cover is connected
to and counterbalanced by the weight O as illustrated.
The stage or platform Q. is provided for charging the furnace with materials
through the top when the cover O. is raised for that purpose.
The auxiliary furnace G. is placed on a wheeled truck R. running upon rails R' in
order that it may be connected to or withdrawn from the opening F. and is provided
with a grate G on which a fire is maintained for the purpose hereinafter specified.
The receiver or ladle I. is also capable of being removed either by means of lifting
rings for the purpose of being conveyed from the furnace to the mould to be cast or
it may be placed in a movable truck and so be transported from place to place.
We now proceed to describe the cycle of operations necessary for the production of
steel for steel castings according to our present invention.
We fill the furnace A. with pieces of dense or compressed carbon or carbon blocks
to a height above the tuyeres E. The ordinary fuel in the auxiliary furnace G. is now
ignited and being connected to the opening F. the flame from such auxiliary furnace
causes the carbon blocks to become red hot and which being effected the auxiliary
furnace G. may be withdrawn.
The opening F. is then closed by means of a plate or door protected by a refractory
lining.
The blast is then turned into the blast chamber C. and passing into the furnace
through the tuyeres D and E. soon raises the already-red-hot carbon to bright
incandescence.
Wrought-iron and steel scrap or either ".
"
per se
or with a certain portion of pig

page_text: (
metal or spiegeleisen is then charged through the open top of the furnace in the
manner in which an ordinary cupola is charged and the cover O. being now dropped
a high pressure of blast is then passed through the furnace the surplus products of
combustion passing off through the outlet P. A charge even of wrought iron
22
per se is rapidly melted and runs in a very liquid state through the interstices of
the carbon blocks or pieces and thence through the channel H. into the receiver or
ladle I. where such additions as may be necessary to cause the steel to run quiet into
the moulds may be added at the discretion of the person in charge. The interstices
between the pieces of carbon can be kept at a reducing or oxidizing state of
incandescence by regulating the pressure and quantity of blast supplied.
The result of this method of melting is that as only pure materials are used in the
furnace A. there is little or no slag produced and the charges can be proportioned to
produce with certainty any desired grade of molten metal.
The furnace is quickly started into operation and burns no fuel except when actually
in use and can be used for one charge or a continuation of charges carbon being
added with each metallic charge sufficient to keep the melting zone at its proper
height.
We do not confine ourselves to the use of the auxiliary furnace G. for heating the
carbon as aforesaid as it can be dispensed with by using a gas flame say from a
regenerative gas furnace or by otherwise heating a sufficient portion of the carbon
before charging into the furnace.
We prefer the carbon to be in irregular pieces and find that the deposited carbon
from gas and oil retorts is a most excellent material to use, it answering the purpose
without grinding and compressing artificially.
We also find that the same cycle of operations and method of fusion is capable of
melting copper tin and other metals, much cheaper and quicker than by the
reverberatory furnace generally used for that
purpose.
Having now fully described and ascertained the nature of our invention and the best
methods with which we are acquainted for properly carrying out the same we declare
that we do not claim broadly the use of carbon for melting metals but what we do
claim as our invention is :-
1st. The improvements in and apparatus for the production of steel for steel castings
and for melting metals substantially as hereinbefore described.
2nd. The combination of a melting furnace with an auxiliary furnace or its
equivalent and receiver substantially as and for the purposes hereinbefore described
and illustrated on the accompanying drawing.
3rd. The employment of preheated blocks of dense or compressed carbon (preferably
gas or oil retort carbon) burnt in an excess of oxygen and kept in a state of
incandescence substantially as and for the purposes herein before described.
4th. The employment of preheated blocks of dense or compressed carbon rendered
incandescent by a powerful blast of air as a means of melting metals in a furnace
substantially as hereinbefore described.
5th. The cycle of operations in the production of steel for steel castings and melting
of metals substantially as hereinbefore described.
JOHN G. WILSON,
Agent for the Applicants.