Improvements in the Process for the Manufacture of Carbide of Calcium, and Apparatus therefor.
Year: 1898

page_text: Improvements in the Process for the Manufacture of Carbide of
Calcium, and Apparatus therefor.
I, GEORGE BOWER, St. Neots, Hunts, Engineer, do hereby declare the nature of
this invention to be as follows:-
Objects of my invention are to make the incandescent process of producing carbide
of calcium continuous, to mechanically stoke the ingredients, and to automatically
control or regulate the operation of the furnace. To these ends my invention
comprises the improvements hereinafter described and claimed.
The nature, characteristic features and scope of my invention will be more
fully understood from the following description taken in connection with the
accompanying drawings forming part hereof and in which
Figure 1, is a top or plan view of an electric furnace embodying features of
my invention.
Figure 2, is a central sectional view of the same, parts being omitted for the
sake of clearness.
Figure 3, is a perspective view illustrating modified means that may be used in
connection with my invention.
In the drawings a is a hopper of which the bottom opens into a chamber 6 of
which the inner end is open and communicates with furnace proper. These parts
may be made of cast and sheet iron. The furnace is trough-shaped and is provided
with an inclined floor c which may be of fire brick protected near the pencils by
carbon and which terminates in a grate d beneath which is a space or pit e.
Within the chamber 6 is a reciprocating rammer f which may be of cast iron.
As shewn this rammer f is connected to one end of a link g the other
end of which is connected to a wrist pin g¹ carried by a rotable wheel g³.
Upon each side of the outlet of the chamber 6 are located electrodes or
pencils and h¹ which may be of carbon. The holders of these electrodes are
pivoted as at ³, for example, to suitable brackets or supports as shewn and are
thus mounted so as to be capable of being turned into the positions indicated by
dotted lines whereby the pencils or electrodes h and may be turned into
proximity with each other and into positions parallel with the side walls of the
furnace. i is a friction clutch which serves to couple and uncouple a positively
driven pulley k to and from the wheel is the operating lever of the
friction clutch i and its free end is connected with a spring and with the

page_text: armature or core 7 of the solenoid or electro-magnet 7. The lever is pivoted
at 3. The windings of the solenoid are arranged in series with the pencils h, h¹,
that is to say, the path of the circuit is 1, 2, 1, 3, h¹, h and 4.
The mode of operation of the above described apparatus is as follows:
The insulated handles h³ are turned so as to bring the electrodes or pencils h, h¹
into proximity with each other, whereupon current is permitted to traverse the
circuit which is closed through material fed in as will be presently described.
The rammer is caused to reciprocate backwards and forwards, for example, by
means of the parts g2 and k, and a mixture of powdered lime and carbon is fed
into the hopper a with the result that it falls into the chamber band is inter-
mittently fed out of the open end b between the electrodes or pencils h and h¹
which are turned into parallelism with each other and with the side walls of the
furnace and are held fixed and immovable in such position. The strength of
current employed is between 1500 and 2000 amperes, and a voltage of sub-
stantially 100 to 110 gives good results. The carbide formed is removed down
the inclined floor c, upon which it cools to the bars of the grate d, on which it
rests whilst the unfused powdered material falls down out of the way into the pit c.
From time to time fresh supplies of powdered material as coke and lime are placed
in the hopper a and the finished carbide is removed from the grate d, the process
itself being continuous. During the process if there is not sufficient carbide
producing material being fed between the terminals h, h³, the resistance between
them will decrease and the current in the circuit will increase, with the result that
the solenoid will overcome the power of the spring and will thus shift the
lever and the rim of the friction clutch i into position for locking the parts k
and g, so that the rammer will be operated. On the other hand, if too much
material is being fed between the electrodes or pencils h, h¹ then the resistance
between them will rise by reason of the presence of such excess of material and
the current in the circuit will fall, thus causing the decreased attractive power of
the solenoid or electro-magnet to be overcome by the spring 3, which draws the
lever, and rim of the clutch i, into the position shewn in the drawings for
uncoupling the parts k and g² so that the rammer is not operated. During the
operation the pencils hand h¹ lie parallel with the direction of motion
of the material through the furnace, so that the motion of the material is not
impeded and the corners or other parts of the pencils are not subjected to liability
of breakage as they would be if they were disposed transversally of the path of
motion of the mixture. The above described furnace is adapted for the practice
of the strictly incandescent process and not of the arc process of manufacture, and
I have found that if an arc is maintained between the electrodes or pencils very
little carbide is formed in comparison in comparison to what is formed when the
mass passing the pencils is subjected to the action of incandescent heating. Inas-
much as the described furnace is of the incandescent type it follows that both
electrodes are completely embedded in material and protected thereby from the
oxydizing influence of the air, so that their life is greatly prolonged. In this
connection it may be remarked that material collects and is permitted to collect
in the furnace for the purpose of covering the electrodes and also the finished
product. Instead of pivoting the pencil holders as shewn, pins A projecting up
from the walls B of the furnace may be provided and used as fulcra for the pencil
holders which may be advanced to take up wear at the inner ends of the pencils.
It will be obvious to those skilled in the art to which my invention appertains
that modifications may be made without departing from the spirit thereof, hence
I do not limit myself to the precise construction and arrangement of parts herein-
above set forth and illustrated in the accompanying drawings.
171
1
T
1000

page_text: improvements in the Process for the Manufacture of Carbide of
Calcium, and Apparatus therefor.
I, GEORGE BOWER, St. Neots, Hunts, 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:-
Objects of my invention are to make the incandescent process of producing carbide
of calcium continuous, to mechanically stoke the ingredients, and to automatically
control or regulate the operation of the furnace. To these ends my invention
comprises the improvements hereinafter described and claimed.
The nature, characteristic features, and scope of my invention will be more
fully understood from the following description taken in connection with the
drawings filed with my Provisional Specification, in which
Figure 1, is a top or plan view of an electric furnace embodying features of
my invention.
Figure 2, is a central sectional view of the same, parts being omitted for the
sake of clearness.
Figure 3, is a perspective view illustrating modified means that may be used in
connection with my invention.
In the drawings a is a hopper the bottom of which opens into a chamber 6 the
inner end of which is open and communicates with furnace proper. These parts
may be made of cast and sheet iron. The furnace is trough-shaped and is provided
with an inclined floor e which may be of fire brick protected near the pencils by
carbon and which terminates in a grate d beneath which is a space or pit e.
Within the chamber b is a reciprocating rammer f which may be of cast iron.
As shewn this rammer f is connected to a wrist pin g¹ carried by a rotatable.
wheel g² Upon each side of the outlet b' of the chamber b are located electrodes or
pencils h and h¹ which may be of carbon. The holders 2 of these electrodes are
pivoted as at h³, for example, to suitable brackets or supports as shewn and are
thus mounted so as to be capable of being turned into the positions indicated by
dotted lines whereby the pencils or electrodes h and h¹ may be turned into
proximity with each other and into positions parallel with the side walls of the
furnace. i is a friction clutch which serves to couple and uncouple a positively
driven pulley k to and from the wheel g². ¹ is the operating lever of the
friction clutch and its free end is connected with a spring and with the
armature or core of the solenoid or electro-magnet . The lever is pivoted
at . The windings of the solenoid are arranged in series with the pencils h, h',
that is to say, the path of the circuit is 1, 2, 1, 3, h¹, h & 2ª.
:-
The mode of operation of the above described apparatus is as follows:-
The insulated handles h are turned so as to bring the electrodes or pencils h, h¹
into proximity with each other, whereupon current is permitted to traverse the
circuit which is closed through material fed in as will be presently described.
The rammer f is caused to reciprocate backwards and forwards, for example, by
means of the parts g² and k, and a mixture of powdered lime and carbon is fed
into the hopper a with the result that it falls into the chamber b and is inter-
mittently fed out of the open end 6' between the electrodes or pencils h and h¹
which are turned into parallelism with each other and the side walls of the
furnace and are held fixed and immovable in such position. The strength of
current employed is between 1500 and 2000 amperes, and a voltage of sub-
stantially 100 to 110 gives good results. The carbide formed is removed down
the inclined floor c, upon which it cools to the bars of the grate d, on which it

page_text: rests whilst the unfused powdered material falls down out of the way into the pit c.
From time to time fresh supplies of powdered material as coke and lime are placed
in the hopper a and the finished carbide is removed from the grate d, the process
itself being continuous. During the process if there is not sufficient carbide
producing material being fed between the terminals h, h¹, the resistance between
them will decrease and the current in the circuit will increase, with the result that
the solenoid will overcome the power of the spring 2 and will thus shift the
lever and the rim of the friction clutch into position for locking the parts k
and g, so that the rammer will be operated. On the other hand, if too much
material is being fed between the electrodes or pencils h, h¹ then the resistance
between them will rise by reason of the presence of such excess of material and
the current in the circuit will fall, thus causing the decreased attractive power of
the solenoid or electro-magnet to be overcome by the spring, which draws the
lever, and rim of the clutch i, into the position shewn in the drawings for
uncoupling the parts and g² so that the rammer is not operated. During the
operation the pencils and lie parallel with the direction of motion
of the material through the furnace, so that the motion of the material is not
impeded and the corners or other parts of the pencils are not subjected to liability
of breakage as they would be if they were disposed transversally of the path of
motion of the mixture. The above described furnace is adapted for the practise
of the strictly incandescent process and not of the arc process of manufacture, and
I have found that if an arc is maintained between the electrodes or pencils, very
little carbide is formed in comparison to what is formed when the mass
passing the pencils is subjected to the action of incandescent heating. Inas-
much as the described furnace is of the incandescent type, it follows that both
electrodes are completely embedded in material and protected thereby from the
oxydizing influence of the air, so that their life is greatly prolonged. In this
connection it may he remarked that material collects and is permitted to collect
in the furnace for the purpose of covering the electrodes and also the finished
product. Instead of pivoting the pencil holders as shewn, pins A projecting un
from the walls B of the furnace may be provided and used as fulcra for the pencil
holders which may be advanced to take up wear at the inner ends of the pencils.
It will be obvious to those skilled in the art to which my invention appertains
that modifications may be made without departing from the spirit thereof, hence
I do not limit myself to the precise construction and arrangement of parts herein
above set forth and illustrated in the drawings which accompanied my Provisional
Specification.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. In combination an electric furnace having a floor, electrodes supported hori-
zontally above said floor, circuit connections for the electrodes, a chamber at one
end of the floor into which material is fed, and a horizontally reciprocating rammer
working between the electrodes and cross-wise of the path of the current between
them, substantially as described.
2. In an electric furnace the combination of a chamber into which material is
fed, a reciprocating rammer for intermittently expelling the material from the
chamber, pencils or electrodes disposed above the floor of the furnace and on
opposite sides of the outlet of the chamber and having their sides arranged
parallel to the line of movement of the rammer, and means for permitting the
electrodes to be shifted, substantially as described.
3. In an electric furnace the combination of a chamber into which the material
is fed, a reciprocating rammer for expelling material from said chamber, pencil
holders pivotally supported on each side of the outlet of said chamber, and
circuit connections for said pencils, substantially as described.
4. In combination an electric furnace having at one end a grate and at its

page_text: middle part an inclined floor, electrodes at the other end of the furnace above
said floor, circuit connections for the electrodes, and a reciprocating rammer for
feeding material between said electrodes, substantially as described.
5. In combination an electric furnace, electrodes and their circuit connections,
a reciprocating rammer working between said electrodes and cross-wise of the
path of the current between them, and electrical devices responding to changes
of current and controlling the movements of the rammer, substantially as
described.
6. In combination an open top electric furnace having an inclined floor and
vertical sides and provided at one end with an off-take, electrodes supported above
and at or near the opposite end of said floor, and circuit connections for the
electrodes, substantially as described.
7. The combination with the electrodes of an electric furnace of a chamber
having discharge and inlet openings, and a reciprocating rammer working between
said electrodes and having a running fit in said chamber and adapted to open and
close the inlet thereto whereby material is intermittently fed, substantially as
described.
1000