Improvements in Metallurgical Furnaces for Steel Making or Cementation Purposes.
Year: 1892

page_text: Date of Application, 19th May, 1892-Accepted, 25th June, 1892
COMPLETE SPECIFICATION.
Improvements in Metallurgical Furnaces for Steel Making or
Cementation Purposes.
We, JULES EUGÈNE FILASSIER of 136 Boulevard Magenta, Paris in the
Republic of France, Architect, and JEAN FAURÉ of 196 Rue Saint Martin, Paris
in the Republic of France, Gentleman, 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 :-
The steel making furnace forming the object of this invention is especially
arranged for converting pieces of iron of variable forms and dimensions into steel
of a homogeneous composition throughout, and also for cementing mechanical or
other parts either to the core or to a certain depth, the articles thus treated at the
same time preserving their original appearance and having neither blisters on their
surface nor other alteration in their form, and of realising further industrial
economies of great importance.
This result is obtained :-
1. By heating at a high temperature the substances to be treated in an
absolutely closed receptacle in such a manner as to prevent any contact of these
substances with the air, or gases of combustion :
2. By the uniform distribution of the heat applied to the outer walls of the
receptacle in order that the temperature may be practically the same at all points
of the interior :
3. By applying a layer of non-conducting material to the furnace walls, which
not only causes a saving of fuel, but above all allows the heat to be concentrated
in the receptacle, and thus renders the operation more rapid or regular.
The invention may be the more easily understood by reference to the accom-
panying sheet of drawings representing the furnace so designed as to realise the
conditions above alluded to.
Figure 1 is an external view of the main front.
Figure 2 is a view of the side front.
Figure 3 is a longitudinal section.
Figure 4 is a cross section.
The receptacle or compartment A is constructed of fire clay and arranged with
panels tongued and grooved together so that it is capable of being taken to pieces.
It
may be preferably rectangular in shape..
This receptacle, according to its dimensions, is heated externally by one or more
fire places B B placed beneath it. Further, in order to raise the temperature and
render it practically uniform throughout the receptacle, we arrange, at a certain
distance up the space C, another grate D, which surrounds the external walls
of A.
The vessel is covered by a lid E, constructed of several long pieces placed side
by side in such a way as to allow of their easy removal by means of the hooks or
rings arranged on the same.
A roof F surmounts the furnace and has a chimney G for discharging the smoke.
A certain number of openings are arranged in this roof, which may be closed by
sliding doors H and which serve to supply the grate D with fuel.
II are passages for conveying heat to the receptacle from the furnace :
JJ passages to the ash pan K.
LL are air supply channels and sight holes.
M is a heating chamber between the lid of the vessel and the roof of the
furnace.
The fuel which fills the space C above the grate D overflows into this chamber
on the edges of the lid E and descends gradually in proportion to the combustion.

page_text: The interior lining of the furnace is of fire brick. On the external walls between
the metal framings, a layer of insulating material is applied, which prevents loss of
heat by radiation.
This insulating layer may also be arranged in the interior of the walls of the
furnace between two thicknesses of brick; but the first arrangement will, we
believe, be found best.
The furnace is provided with an easily accessible pyrometer, or other suitable
indicating means visible to the outside.
The materials, namely iron and the cementing substances, are arranged in the
receptacle A in alternate layers, the respective thicknesses of which may be varied
according to the thickness of the articles, or the amount of conversion into steel
which it is desired to accomplish.
The lid is then carefully placed on, the joints being carefully luted, and the
furnace is heated by progressively raising the temperature up to 700 or 800 degrees
for instance. At the end of a suitable time, about 72 hours, the heating is
suspended and it is allowed to cool slowly.
Steel obtained by this process and with this apparatus does not require to be
sorted or forged or melted in a crucible in order to yield a homogeneous metal.
It may be taken at once to be forged or rolled into any desired shape; and its
surface will be found smooth and free from blisters and 'flakes. 'It can be welded
and will stand' tempering very well.
All qualities of steel required for different purposes may also be obtained as
desired.
"Finished articles may also be cemented right through or only partially so by this
apparatus, and may then be withdrawn without their form or the edges being in
any way affected, but after there has been imparted to them the special qualities
owing to their being made more or less steely according to requirements.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what'we
claim is :
1. The improved construction, substantially as hereinbefore described and shown,
of metallurgical furnace with a view to the production of a high temperature and a
uniform and concentrated heat, and also the application of such for the conversion
of iron into steel or for the partial or total cementation of parts of machinery and
the like.
2. The general construction and arrangement of parts forming the metallurgical
furnace for steel making or cementation purposes, substantially as hereinbefore set
forth.
"Dated this 18th day of Mer 1909
WM. P. THOMPSON & Co.,
⚫ Of 6, Lord Street, Liverpool, Agents for the" Applicants.