Year: 1896

page_text: A. communication from OCTAVE PATIN, ot Paris, in the repono
I, ALFRED JULIUS BOULT, of 111 Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention to be
as follows:-
This invention relates to electrical furnaces particularly adapted for the manu-
facture of calcium carbide, and melting in a vacuum, bodies which are liable to
become oxidised by the action of the air.
The apparatus is capable of being hermetically closed in such a manner that
it is possible to produce a vacuum or to work under pressure, according to
requiremente.
It is provided with a sufficient number of branches for enabling the
gases
discharged and to be introduced, and it is also provided with "locks" or double
slide valves for enabling the substance to be treated, to be introduced without
interrupting the working of the furnace.
The substance to be treated is moved or brought in front of the electrodes by
means of a piston which works in the lower part of the furnace; its movement
being automatically regulated according to requirements and to the intensity of the
beat of the furnace, the material or substance being introduced at the top of the
furnace and after having been treated comes out at the bottom; an important point
of the invention being to cause the material to be moved as the treatment by the
electrodes proceeds.
The movement of the material may also be obtained by any other means, as for
instance by locks or slides or simply by the instantaneous opening of the bottom,
or by means of a wheel with floats or buckets etc., but I consider the piston as the
most suitable as it has the advantage of, not stirring up or disturbing the material.
The piston moves under the influence of its weight and the regulating is effected
by an electro-magnet attracting a pawl which starts an unwinding or lowering
mechanism having a slow motion when the intensity of the heat becomes too great.
This furnace may be used in all cases when substances requiring high tempéra-
tures are to be treated, such as in the manufacture of calcium carbide; the caloric
action is localised at the points of the carbons and the substance itself constitutes
a heat-insulating medium, and by means of a circulation of water round the
furnace and the carbon-holders it is possible to maintain their temperature at the
desired height.
This apparatus may be constructed of cast-iron but it also may be made of
bronze, sheet-iron, refractory brick-work or other suitable material.
The apparatus consists of five parts-
1) A magazine provided with "locks" or double doors receiving the substance
or material to be treated.
2) The furnace proper placed beneath and carrying two electrodes and the
meobanism for supplying electric current to them and for regulating their position
as well as water circulation mechanism.
3) The extraction oylinder, its piston and valve.

page_text: WORKING OF THE APPARATUS.
The two electrodes being in contact, and the piston at the top of its stroke, the
material to be treated is introduced into the furnace through the charging chamber
till-it is filled to the height of the valve of this charging chamber, the level being
observed through the window.
The current is then started, the electrodes being moved apart to produce the
necessary arc, the operation being observed through the window in the furnace.
Then the piston is slowly lowered as the substance to be produced is formed.

page_text: If necessary the apparatus may be charged again by operating the upper look
or valvo.
When the piston has nearly arrived at the lower end of its.course, it is allowed
to descend until the lower valve can be closed without meeting maoh resistanco
from the material.
This valve is then closed, the substance produced and the dust or other material
surrounding it are removed; the piston is thereupon raised until it comes in contact
with the valve, which is afterwards opened, and the operation continuos.
BOULT & WADE,
. Agents for the Applicant..
A communication from OCTAVE PATIN, formerly of Paris, now of 3 Rue du
Ohateau, Puteaux, Seine, in the Republic of France.
I, ALFRED JULIUS BOULT, of 111 Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, 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 relates to electrical furnaces particularly adapted for the
manufacture of calcium carbide and treating in vacuum bodies which are liable to
become oxidized by the action of air.
The apparatus is capable of being hermetically closed so that a vacuum may be
produced therein or the work may be done under pressure according to circum-
stances, aud it is provided with a suitable number of branches to enable the gases
to be discharged or introduced and it is also provided with "locks" or slide
valves to enable the material to be treated to be introduced without necessitating
the interruption of the working of the furnace.
The material. to be treated is brought under the action of the electrodes by
means of a piston working in the lower part of the furnace its movement being
automatically regulated according to the intensity of the heat. The material'
introduced at the top of the furnace is discharged at the bottom after treatment.
The important feature of the invention is the moving of the material as it is being
treated by the electrodes.
This movement may be attained also in other ways, such for instance as locks or
slides or simply by the quick epening of the bottom or by means of a wheel
provided with blades or buckets etc., but the piston is considered the most suitable
as it does not stir up or disturb the material.
The piston moves by its own weight and the regulation of its movement may be
effected by a simple electro-magnet attracting an armature which releases a slow-
aoting lowering mechanism when the heat is become very intense.
This furnace may be used in all cases when substances requiring high temperature
are to be treated for instance in the manufacture of calcium carbide; the caloric
action is localised at the points of the carbons and the material itself serves as a
thermic insulator the heat of the furnace and carbons-holders being maintained at.
a desired temperature by water circulating round them.
The apparatus is generally made of cast-iron, but it may also be of any other
metal, bronze, sheet-metal, refractory bricks, or other suitable material or
matoriale.

page_text: in the accompanying drawings,
Figure 1 is an elevation of the whole apparatus partly in section,
Figure 2 is an elevation partly in section of the electrode holder,
Figures 3, 4, 5 are detail views.
The apparatus comprises the following essential parts:
1. A magazine a provided with locks or double doors receiving the material
to be treated.
2. The furnace proper 6 placed below and oarrying the two electrodes and the
parts for supplying current to them, for moving them and the water-circulation
parts.
3. The extraction or removal chamber c its piston and valve.
4. The foundation standard d carrying the piston operating device.
5. A cast-iron columo e serving as a sheath or sleeve for the piston-rud.
The magazine a with its locks or slides is constituted by a chamber of square,
cylindrical or any other desired shape. It is closed at the top by a cover i of cast
iron or any other material on which are symmetrically or otherwise arranged several
branches or outlets.
1. A branch for the safety valve when working under pressure (not shown in
the drawing).
2. A branch for the
pressure gauge.
3. A charging branch provided with one or two valves constituting the "lock."
4. A branch m for the vacuum gauge.
5. A suction or discharge branch j for gases.
The branches 1, 2, 4", 5 have no special features.
In the suction and discharge outlets for gases terminating at the upper end of
the magazine a is interposed a dust-trap (not shown in the drawing).
The charging branch I has at the top a valve n operated by a hand wheel o and
opening or closing in an air-tight manner the orifice of the branch / through which
the charging is effected.
A window fof glass, mica or other transparent material is arranged above the
second valve p of the "lock" so as to enable the quantity of the material in the
magazino a to be observed.
The second valve p enables the magazine a to be divided into two parts and
completely cuts off one section of the chamber from the other. Its construction is
the same as that of the valve n and comprises :-
A hermetically closed chamber 9.
A screw spindler with a quick pitch and provided at its outer end with an hand
wheel. The screw is supported by means of shoulders against the wall of the
furnace on one end and in the cover of the chamber 9 at its other end.
A nut with which the screw engages, is secured to the valve p.
By simply turning the hand-wheel in one or the other direction the valve p may
bo drawn forwards or backwards as desired to either open or close the opening in
the chamber a.
The furnace proper is constituted by a chamber b secured to the magazine a by
means of a flange u or in any other way. It is provided with two diametrically
opposite flanged openings which receive the electrode holders. These flanges
are preferably oblique so as to give the electrodes an inclination towards the
bottom of the furnace.
An aunular water chamber y is provided with two diametrically opposite
branches for admission and discharge of water.
The water of the chamber y circulates round the electrodes through the
passage 1.
The electrode-holders are secured by means of their flanges 2 to the flanges
from which they are electrically insulated by packing 3 3 of asbestos mica, or
other insulating incombustible material as shown in Figure 3.
The electrode-holders consist of a rigid frame formed by two sorew-threaded,
rods 4 & 41 connected at one end by a transverse rod or bar 5 provided in the

page_text: centre with a collar 6, through which the electrodes pass and at the other end by
the flange 2. The part 7 7 secured to or forming part of the flange 2 is provided
at its lower end with a hole the diameter of which is equal to that of the electrodes
and is formed interiorly in the shape shown in the drawing, that is to say it has
conical walls. 881 is a chamber in which water circulates for cooling the electrodes,
said chamber communicating with the channel y of the furnace by the tubes 1.
The part 9 is secured to the part 7.
The tightening of the electrodes is effected as follows:-
The inner part 10 is provided in its centre with a hole the diameter of which is
about the same as that of the electrodes and terminates as shown in a cone fitting
exactly into the coned part 9 and its extremity comes against the cap 11. It is
rendered elastic at its conical end by means of longitudinal cuts made at intervals
thus taking away the rigidity of the metal.
By screwing the cap 11 it is obvious that the conical part 10 will be caused to
advance. The more it advances the more its cone penetrates into that of the
part 9 and the inner diameter of 10 becomes smaller cousequently the carbon is
held tightly the part 11 is screwed down until the electrode is in good contact with
the part 9 and consequently with 7 through which the current arrives as indicated
by terminals 12 12' (Figure 1).
The movement of the carbons is effected by means of the following device,
The electrode is clamped by a part 18 secured to the part 14. The latter has
2 worm wheels 15 and 15 which are also provided in their interior with screw-
threads of the same pitoh as the rods 4 and 4'. These wheels are held by the
part 14. They are driven by two worms 16 (Fig. 4) which are mounted on the
same shaft 24 and actuated by a crank 25 worked by hand or mechanically.
When the crank is turned the 2 worms 16 impart rotary motion to the worm
wheels 16 and 15'.
The nuts being sorewed on the 'movable rods 4 and 41 their rotation causes the
whole device to move upwards or downwards with them; so that the carbons
may be thus moved forwards or backwards.
The chamber b of the furnace is provided with an eye-hole y placed, as shown
in the drawings, at about the same height as the ends of the electrodes, so that the
progress of the operation may be observed.
The extraction or withdrawal chamber. This chambor c is connected to the
furnace by its upper flange 17 and to the standard by its lower flange 18 and is
provided at the top with a valve or "lock" 19 which is similar to the one in the
chamber a.
The chamber is also provided with a piston 20 tho rod of which is provided
with a toothed rack 21. The rod is screwed into the piston or secured to it in any
similar manner.
On the upper face the piston may be provided with a layer 22 of refractory
material asbestos etc., and is guided by the walls of the chamber which it fits.
The standard d is made of cast-iron or any other metal or of brickwork. It
receives the lower flange 18 of the extraction chamber and carries the shaft 23
mounted on it in bearings and operating the pinion 23' of the toothed piston rod 21.
The column e is of metal or brick work; and simply constitutes a sheath for
guiding and receiving the piston rod 21.
The operation of the apparatus is as follows :-
The two electrodes are brought in contact that is to say in position indicated
in the drawing (Figure 1). The points meet in about the centre of the furnace.
The pistou is raised to the end of its stroke and is consequently a little
below the points of the electrodes. All the valves are then open. The material
to be treated is introduced into the furnace through the branch either by hand
or by a mechanical charging device till the furnace is filled up to the valve p.
This level may be observed through the eye-hole f.
Then the current is passed through the electrodes which are separated_by
operating electrode holders in the manuer indicated, so as to start the arc.
The

page_text: eye-liule y enables the lighting to be observed: Measuring apparatus may be used
to indicate the consumption and the arc may be regulated according to circum-
stances either by varying the resistanco in the circuit or by moving the electrodes
further away from or nearer to each other.
When the material is fused the pistou 20 is slowly lowered. by operating the
crank of the shaft driving the pinion 23 and as the material desired is produced.
the piston continues to be lowered by operating in the manner describeil.
If it is necessary to add further material it is effected through the branch 1.
When the piston has arrived at the bottom of its stroke that is to say when the
operation is finished the discharge is effected as follows:-
The current is interrupted the piston 20 is then at the bottom of its stroke so
that the top of the carbide block produced is under the valve 19. The latter not
meeting any resisting material can then be closed. During the time that the
carbide block is left to cool before being removed the valve p is closed and the
upper part of the magazine a is charged through the branch l the valve n.being
then closed.
The carbide having been withdrawn through a door suitably arranged in one
side of the standard the piston is raised until it comes under the valve 19 which
is opened. The valve p is then opened and admits the new charge contained in
the upper part of the magazine a without allowing any dust to escape. This
charge thus enters into the furnace proper the current is again switched on to the
electrodes and the operation starts afresh.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent and in what manner the
same is to be performed I declare that what 1 claim is :-
1. In an electrical furnace a vertically movable piston operated by a rack and
piston or equivalent device, substantially as and for the purpose described.
2. In an electrical furnace electrode holders provided with cooling water
passages and mechanism for adjusting the carbons without moving the carbon
holders substantially as described.
8. In an electrical furnace the combination of parts for holding and adjusting
the carbons substantially as described and illustrated in Figure 2 of the accom-
panying drawings.
4. The combination and arrangement of parts constituting the complete
electrical furnace substantially as described and illustrated in Figure 1 of the
accompanying drawings.
.