New Construction of Converter-apparatus for Producing Steel and Wrought Iron of Superior Quality.
Year: 1897

page_text: Date of Application, 23rd Nov., 1897-Accepted, 1st Jan., 1898
COMPLETE SPECIFICATION.
New Construction of Converter-apparatus for Producing Steel and
Wrought Iron of Superior Quality.
I, TOUSSAINT LEVOZ, of Stenay, Meuse, France, Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
This invention has for its object a new construction of converter-apparatus for
the production of a superior quality of steel or iron for ingots or castings by means
of air blast, while using raw materials for this purpose that are less expensive than
those used in the Bessemer process.
In general, the mixture of materials employed in the Siemens Martin process
may be used, while the apparatus is of a more simple construction, and main-
tainable at a less cost, the metal produced being at the same time better suited
to the purposes required.
I will describe my said invention with reference to the accompanying drawing,
where Fig. 1 shews a plan of the apparatus, and Fig. 2 a vertical section on
line A-B.
The apparatus consists of two recipients of sheet iron R, R', communicating with
each other by means of a tubular part C, the whole being provided with a refractory
lining, and the complete apparatus is divided into three parts for facilitating
repairs. The part C is provided with a steel belt carrying two trunnions TT.
The trunnion T is partly hollow and serves for the passage of the air blast from a
blowing engine, the blast being led thence to the recipient I through the pipe t,
wind chest V, and lateral tuyeres.
The trunnion T serves to receive the requisite rocking motion for the apparatus,
which is imparted either by hand or by mechanical or hydraulic power.
The two trunnions are carried on chairs which allow the apparatus to be manipu-
lated in a similar manner to ordinary converters.
The tuyeres in the recipient R are made convergent and are inclined towards
the bottom or bed of the recipient, so that the jets of air will pass through the bath
of metal from above downwards, under a pressure of about 50 centimetres of
mercury. In the drawing the tuyeres are shewn in a lateral position. They may
however be arranged so as to inject the air either from below or from above the
bath; that is to say, the form of the apparatus can be adapted to any description
of blast.
The opening serves for the introduction of the liquid cast iron into the
recipient R; it also serves for the inspection and repairs of the tuyeres.
This opening is closed during the working, in order to force the gases to pass
into the recipient R¹.
The opening serves for discharging the gases after they have heated the
recipient R'; it serves also for running off the metal when all the operations have
been completed.
It is to be observed that the entire arrangement of the lateral tuyeres in a con-

page_text: verging position and inclined towards the bed must be scrupulously maintained
for obtaining the maximum amount of heat given off by the combustion of the
gases produced by the oxydation of the carbon and other elements contained in
the cast iron.
The process of conversion by means of this apparatus is carried out as follows:-
The cast iron previously melted down in an ordinary cupola, will have about
2 per cent. of silicon when it enters the recipient R; this percentage can also be
obtained by employing the most silecious cast iron, to which is added scrap iron in
the cupola. This cast iron, in being at once subjected to the oxidising action of
the blast in the recipient It, is rapidly heated up by the combustion of the silicon,
it soon attains the temperature of fusion of steel or wrought iron by the oxidation
of the carbon; the cast iron bath develops at this moment more than 2,000° C.
The characteristic flame of the heat produced, instead of passing into the atmos-
phere through the opening b, passes through the tubular passage into the
recipient R, which it heats to a high degree, escaping eventually through the
opening b¹ In proportion as the heat increases in the recipient R', there is intro-
duced through the opening biron or steel scrap, which is fused by the heat of
the gases passing off from R. A minute before the termination of the operation
there are introduced, also through b, the different additions of ferromanganese,
ferrosilicon, or silicic spiegel-iron, in order to prevent too great a degree of oxidation
of the fused scrap-
The operation being completed, the apparatus is inclined so that the bath of
metal contained in R passes into R; the mixture then at once takes place in au
intimate manner, owing to the great heat of the bath.
A sample is then taken, in a similar manner to the Siemens-Martin process,
and if the metal is not in the condition desired, farther scrap may be added by
means of spiegeleisen or powdered coke. The metal obtained as above described
will not be subject to ebullition when the carbon is added, which proves the
superiority of the metal over all the steel obtained either in the Siemens-Martin
furnace or in the ordinary converter, as, if there were ebullition this would show
the presence of oxide of iron in the bath. Owing to the favourable arrangement
of the apparatus the steel or iron bath will have retained sufficient heat to allow of
its being run into moulds through the spout b'.
The advantages obtained by the above described invention, in particular for
foundries, may be stated as follows.
1. A mixture of cast iron and very cheap steel may be treated without having
recourse to the very expensive regenerative gas furnaces of the Siemens-Martin
process.
2. The metal which may be thrown out of the recipient K, instead of being
lost as in the case of the Bessemer converter, is caught in the recipient R'.
3. The waste will be greatly reduced.
4. The lining of the recipient R, being in less direct contact with the atmos-
pheric air, will wear less rapidly.
5. The additious of scrap will readily allow of increasing the charge treated
and of casting large pieces.
6. The additions of soft iron will allow of the production of a uniform metal
for use in electrical apparatus.
7. The manner of treating the cast iron as regards the oxidation and admixture
of scrap will afford a liquid metal which will attack the moulding sand less; the
casting will consequently be more easily cleaned of adhering sand.
8. For the same reasons the metal will have no blow holes or honeycomb and,
which is essential, cavities due to shrinkage, and settling &c. will be avoided, a
result which has never yet been obtained.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is:-
Apparatus for the manufacture of iron and steel of superior quality consisting

page_text: essentially of two recipients such as R and R connected together by a tubular
part C, one of which parts R, which receives the charge of molten metal through
the opening b, carries the wind chest and receives the air blast by means of con-
verging tuyeres inclined towards the bottom or bed, and arranged at a suitable height
for forcing the air to pass through the molten cast iron, (the wind chest and tuyeres
being also capable of being arranged for applying the blast from below or at the
surface of the bath), while the chamber R₁ serves to store the heat given off from
the first recipient, and for receiving and effecting the fusion of the charges of scrap
metal, and additions of ferro-manganese, ferro silicon, or other matters, the said
apparatus being mounted on trunnions so as to enable it to be tilted at the end
of the operation in order to form in the recipient R' the intimate and immediate
mixture of the fused materials contained in the two recipients, substantially as
described.
ABEL & IMRAY,
Agents for the Applicant.