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

page_text: [Communicated from abroad by JAMES ELLICOTT HEWES, 421, Chestnut Street,
Philadelphia, Pennsylvania, U.S.A., Electrical and Mechanical Engineer.]
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;-
In the production of calcium carbide by means of electricity and by the
combination of carbon and calcium present in a mass which is usually employed
in the form of a powder, gases are evolved which in escaping drive particles of
calcium oxide out of the zone of high temperature, thus interfering with the
chemical action. Such gases also in effecting their escape from the furnace
honey-comb the mass and also throw a considerable quantity of it out of the
furnace, whereby considerable waste and loss are incurred.
One object of my invention is to avoid these defects and disadvantages and to
provide for the escape of such gases as are or may be generated whilst the pro-
duction of carbide is going on.
For purposes of description I have illustrated in the accompanying drawings a
view partly in section and partly in elevation of one type of electric furnace
adapted for use in practising my invention, although other types of furnaces
may be employed.
In the drawings a is a furnace provided with electrodes b and c of which the latter
is or may be adjustable. d is a source of electric current having electrical connec-
tions as e and el to the respective electrodes. In practising my invention, the
ingredients which contain the carbon and calcium destined to form the calcium
carbide are assembled with due regard to chemical equivalents in the form of
briquettes, pastiles or small cakes, and these briquettes or cakes are placed in a
furnace and are subjected to the action of heat. The gases evolved by reason of
the ensuing chemical action escape without undue commotion by way of the
spaces between the briquettes, pastiles, or cakes. Inasmuch as the gas escapes
between, past, and around the briquettes or cakes, it follows that the mass is not
honey-combed, that particles of calcium oxide are not driven out of the zone of
highest temperature, and that the mass is not driven or impelled or thrown out
of the top of the furnace, all of which is obviously important and results in the
production of a uniform quality of calcium and to the avoidance of waste
in the process. The presence of air and the absence of an electrical path of good
conductivity between the respective cakes or briquettes effectively opposes the
waste of current that tends to leak around the electrodes and through the material
surrounding the effective zone. Proper proportions of the ingredients which
contain the elements necessary for the production of carbide of calcium are
formed into cakes, pastiles, or briquettes for example by means of pressure and
in a mold. To facilitate this operation use may be made of a binder, as sugar,

page_text: asphaltum, molasses, tar, pitch, or equivalent carbonaceous material, and of heat
for drying purposes. I preferably use a binder that will be converted into carbon
which enters into combination for the production of the finished article. However,
a volatile binder as coal tar might be employed. The action of the furnace is
to prepare the constituent particles of each cake exposed to the requisite degree
of heat for chemical combination which by reason of the close proximity in the
cake of the nascent calcium and carbon takes place with comparatively little
waste. The shape or conformation, as well as the size of the cakes, pastiles, or
briquettes may be varied within wide limits and is not of great importance
so long as sufficient space is left between them for permitting of the ready escape
of those gases generated by the chemical combination which produces the carbide,
whereby the described advantages of my invention are accomplished.
The use of the proper proportions of carbide producing materials in the form
of briquettes as described, in connection with an electric furnace is productive
of peculiar and beneficial results. For example; since the ingredients in the
briquettes are compressed, it follows that they are in close mechanical contact,
each particle with the other, so that there is good contact and a good path for the
passage of the current; whereas when the ingredients are employed in powdered
form each particle is as it were separated and insulated from the others by air
spaces, which are nonconductors. Moreover, the briquettes considered as a whole
present a comparatively large surface of contact to each other, and therefore the
electrical resistance is reduced. If the arc is lost, or in other words, becomes
extinguished, in cases where the materials are employed in the form of powder,
then it is exceedingly difficult to re-establish the arc if any of the powdered
material has fallen in between the face of the pencil and the surface of the
carbide, which usually occurs because such powdered material is an exceedingly
poor conductor, as has been already stated. In the case of the described briquettes
the arc may be readily re-established, because if one or more briquettes should
fall into the space between the face of the pencil and the surface of the carbide,
then such briquettes, being in themselves good conductors permit of the ready
re-establishment of the arc. Since the briquettes increase the electric conduc-
tivity of the charge it follows that the zone of high temperature is considerably
increased, so that the ingot produced is materially larger than, would be the case
if the carbide producing material were employed in powdered form.
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 hereinabove
set forth.
1
1000
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 4
this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
In the production of calcium carbide by means of electricity and by the
combination of carbon and calcium present in a mass which is usually employed

page_text: in the form of a powder, gases are evolved which in escaping drive particles of
calcium oxide out of the zone of high temperature, thus interfering with the
chemical action. Such gases also in effecting their escape from the furnace
honey-comb the mass and also throw a considerable quantity of it out of the
furnace, whereby considerable waste and loss are incurred.
One object of my invention is to avoid these defects and disadvantages and to
provide for the escape of such gases as are or may be generated whilst the pro-
duction of carbide is going on.
a
For purposes of description I have illustrated in the drawing,
view partly in section and partly in elevation of one type of electric furnace
adapted for use in practising my invention, although other types of furnaces
may be employed.
be
In the drawings filed with my Provisional Specification a is a furnace
provided with electrodes band of which the latter is or may
adjustable. d is a source of electric current having electrical connections
as e and el to the respective electrodes. In practising my invention, the
ingredients which contain the carbon and calcium destined to form the calcium
carbide are assembled with due regard to chemical equivalents in the form of
briquettes, pastilles or small cakes, and these briquettes or cakes are placed in a
furnace and are subjected to the action of heat. The gases evolved by reason of
the ensuing chemical action escape without undue commotion by way of the
spaces between the briquettes, pastilles, or cakes. Inasmuch as the gas escapes
between, past, and around the briquettes or cakes it follows that the mass is not
honey-combed that particles of calcium oxide are not driven out of the zone of
highest temperature, and that the mass is not driven or impelled or thrown out
of the top of the furnace, all of which is obviously important and results in the
production of a uniform quality of calcium carbide and to the avoidance of waste
in the process. The presence of air and the absence of an electrical path of good
conductivity between the respective cakes or briquettes effectively opposes the
waste of current that tends to leak around the electrodes and through the material
surrounding the effective zone. Proper proportions of the ingredients which
contain the elements necessary for the production of carbide of calcium are
formed into cakes, pastilles, or briquettes for example by means of pressure and
in a mould. To facilitate this operation use may be made of a binder, as sugar,
asphaltum, molasses, tar, pitch, or equivalent carbonaceous material, and of heat
for drying purposes, such binder being used in the proportion found necessary
for the adhesion of the substances used when formed into briquettes.
I preferably use a binder that will be converted into carbon which
enters into combination for the production of the finished article. However,
a volatile binder as coal tar might be employed. The action of the furnace is
to prepare the constituent particles of each cake exposed to the requisite degree
of heat for chemical combination which by reason of the close proximity in the
cake of the nascent calcium and carbon takes place with comparatively little
waste. The shape or conformation, as well as the size of the cakes, pastilles, or
briquettes may be varied within wide limits and is not 'of great importance
so long as sufficient space is left between them for permitting of the ready escape
of those gases generated by the chemical combination which produces the carbide,
whereby the described advantages of my invention are accomplished.
The use of the proper proportions of carbide producing materials in the form
of briquettes as described, in connection with an electric furnace is productive
of peculiar and beneficial results. For example, since the ingredients in the
briquettes are compressed, it follows that they are in close mechanical contact,
each particle with the other, so that there is good contact and a good path for the
passage of the current; whereas when the ingredients are employed in powdered
form, each particle is as it were separated and insulated from the others by air
spaces, which are nonconductors. Moreover, the briquettes considered as a whole,
present a comparatively large surface of contact to each other, and therefore the

page_text: electrical resistance is reduced. If the arc is lost or in other words, becomes
extinguished, in cases where the materials are employed in the form of powder,
then it is exceedingly difficult to re-establish the arc if any of the powdered
material has fallen in between the face of the pencil and the surface of the
carbide, which usually occurs because such powdered material is an exceedingly
poor conductor, as has been already stated. In the case of the described briquettes
the arc may be readily re-established, because if one or more briquettes should
fall into the space between the face of the pencil and the surface of the carbide
then such briquettes, being in themselves good conductors permit of the ready
re-establishment of the arc. Since the briquettes increase the electric conduc-
tivity of the charge it follows that the zone of high temperature is considerably
increased, so that the ingot produced is materially larger than would be the case
if the carbide producing material were employed in powdered form.
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 hereinabove
set forth.
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. The improved process for the manufacture of carbide of calcium and appa-
ratus therefor, substantially as described and illustrated herein and for the purpose
set forth.
2. In a process for the manufacture of carbide of calcium: moulding, pressing,
or forming the required material or materials for the production of carbide of
calcium into briquettes pastilles or small cakes for the purpose of
preventing the escaping or driving off of particles of one or more of the ingre-
dients out of the zone of high temperature when under the action of an electric
arc or current.
3. In a process for the production of carbide of calcium: the admixture of
suitable binding material such as sugar, asphaltum, molasses, tar, pitch, or an
equivalent carbonaceous material in the required proportions with the necessary
ingredients for the production of carbide of calcium and then moulding, pressing,
or forming the composition into briquettes, pastilles, or cakes which are subjected
to the action of an electric arc or current, for the purpose set forth.
Dotal thin 5th day of T..... 1000

page_text: Date of Application, 25th Jan., 1898
Complete Specification Left, 25th Oct., 1898-Accepted, 10th Dec., 1898
[Communicated from abroad by JAMES ELLICOTT HEWES, 421, Chestnut Street,
Philadelphia, Pennsylvania, U.S.A., Electrical and Mechanical Engineer.]
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:-
The principal objects of the present invention are, first, to obviate waste of raw
material, effect a saving in the use of electricity and produce carbide of uniform and
superior quality, and second, to improve the construction and arrangement of the
furnace to the end that labour may be saved and complicated electrical connections
dispensed with.
My invention consists in the improvements hereinafter described.
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 view partly in section of a furnace embodying features of my invention
and adapted for carrying my process into effect.
Figure 2 is a top or plan view of the same.
Figure 3 is a sectional view taken on the line 3-3 Fig. 2.
In the drawings, a is the masonry or other base of a horizontal electric furnace.
Upon the base a is mounted a plate b of metal, as cast iron, which constitutes a
terminal. The electrode c of conducting material, as copper, is afforded a range of
horizontal motion by means, for example, of the wheel and screw and hand wheel e.
The source of electricity and electrical connections are designated by the reference
letters f, g, and g¹. h is a movable hopper of metal, as iron, that may be provided
with eyes, as h¹ to which hooks or cords may be attached for the purpose of lifting it
bodily from the furnace bed or foundation a. This hopper is provided with a plate like
electrode i, of metal, as cast iron, having a base or flange as shewn that rests upon
and makes contact with the plate or terminal b. It is also provided with suitable side
walls. Opposite to the electrode i may be a wall or abutinent j. Mounted in the
electrode c are a number of pencils or carbons of which those designated
longer than those designated ¹ or at any rate the pencils k protrude further than
the others for purposes to be presently described. The number of carbons in
each set is not important and may be varied. As shewn in the drawings, there are
four long or protruding pencils k, and twelve short pencils k¹. Provision is made for
controlling the electrical conditions of the circuit. For example I have shewn a
shunt wound dynamo f whose field coils are connected in series with a rheostat f.
Coke or refuse calcium carbide in limited quantity as shewn at A, is placed in the
hopper in order to protect the plate forming the electrode and the pencils are
brought into contact with the plate like part of the electrode i thus completing the
circuit f, g, b, i, k, c, gl, see Fig. 1. Since the pencils are longer than the pencils /¹
the circuit is closed through the former only. Carbon ground so as to pass for
*
are

page_text: example through a forty mesh, is inserted into the hopper until it is one third full,
more or less. This underlying layer of carbon is designated l. mixture m, con-
taining carbon and calcium generally in the form of lime is then put on top of the
layer of carbon, and a top layer of broken coke or bricks, stones and the like as n
about a foot thick is placed upon the mixture of carbide producing materials m. The
electrode c is now moved toward the right, or in other words, away from the elec-
trode i and there is maintained a current of for example a thousand amperes at the
long pencils or carbons, which may be sixty four inches in cross section. This
gives rise to the rapid production of a thin shaft or core or conducting path of
calcium carbide which is impure or incomplete in that it contains a large quantity of
fused lime which will absorb carbon slowly, it being understood that the electrodes
are gradually separated during its formation. Upon the completion of a shaft or
core or conducting path of the required length, the pencils or carbons are forced
back (that is toward the left in the drawings) into the mass of carbide and unfinished
mixture far enough to complete the circuit through all the pencils, both long and
short. The current now flows from the faces of all the pencils and tends to increase.
in amperage. However, I restrain such tendency in any appropriate manner, for
example, by reducing the voltage by means of the insertion of induction in the case
of alternating current or of resistance with a direct current, or the proper manipula-
tion of the exciting current of the dynamo to about five thousand amperes. As
shewn in Figure 1 the voltage may be reduced for this purpose by increasing the
resistance in the field of the shunt wound dynamo by means of the rheostat. The
carbide shaft or "teazer is a good conductor and reinains incandescent, thus causing
the particles of the carbide producing mixture m which lie in a zone surrounding it
to be chemically combined so that the mass of calcium carbide does not increase in
length but does increase or grow in diameter concentrically. Since the teazer or
shaft is a good conductor and since it is made to carry an excessive current, it follows
that the current flowing through it keeps it hot. It may be remarked that through
these operations, the top layer or coke n permits the gases generated to escape
through it, but it retains the carbide producing material and prevents it from being
thrown out at the top so that a saving is effected. Moreover, the furnace being
properly charged, no further stoking is necessary because the mass of carbide of
calcium increases in diameter as has been explained and this absence of stoking is
obviously a desirable feature. Moreover, the pencils require no further movement
until the completion of the operation upon the charge, so that the attendant may
devote his time to other useful things. Since the carbon pencils, k, are completely
embedded at all times they are not exposed to the air and therefore are not consumed
or burned and last a comparatively long time. The carbon strewn upon the floor of
the furnace and constituting the layer is of course brought into contact with the
diametrically growing mass of calcium carbide, which contains considerable free
molten lime and nascent calcium, and the latter absorbs this carbon chemically as
does also the highly heated calcium carbide and thus produces calcium carbide con-
taining the maximum amount of carbon, i.e. as much carbon as the calcium can
combine with. Such carbide of calcium is not necessarily crystalline like normal
carbide and I have found that from it may be produced from six to six and two-tenths
cubic feet of acetylene gas to the pound, whereas normal crystalline carbide of
calcium I have found to produce not more than five and five tenths cubic feet of
acetylene gas to the pound. While I have spoken of the described calcium carbide
which contains the maximum amount of carbon as not being crystalline, still I
desire it to be understood that such carbide may and sometimes does contain particles
of crystalline carbide. Upon the completion of the treatment of the material con-
tained in one hopper it may be removed and replaced by another hopper and the
finished product may be dumped from its containing hopper.
Dated this 1741
La 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 perforined, to be
particularly described and ascertained in and by the following statement :-
The principal objects of the present invention are, first, to obviate waste of raw
material, effect a saving in the use of electricity and produce carbide of uniform and
superior quality, and second, to improve the construction and arrangement of the
furnace to the end that labour may be saved and complicated electrical connections
dispensed with.
My invention consists in 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 and in which
Figure 1 is a view partly in section of a furnace embodying features of my
invention and adapted for carrying my process into effect.
Figure 2 is a top or plan view of the same.
Figure 3 is a sectional view taken on the line 3-3 of Figure 1.
In the drawings, a is the masonry or other base of a horizontal electric fur-
nace. Upon the base is mounted a plate b of metal, as cast iron, which
constitutes a terminal. The electrode c of conducting material, as copper, is afforded
a range of horizontal motion by means, for example, of the wheel and screw and
hand wheel e. The source of electricity and electrical connections are designated by
the reference letters f, g, and g¹. h is a movable hopper of metal, as iron, that may
be provided with eyes, as h¹ to which hooks or cords may be attached for the purpose
of lifting it bodily from the furnace bed or foundation (. This hopper is provided
with a plate like electrode i, of metal, as cast iron, having a base or flange as shewn
that rests upon and makes contact with the plate or terminal b. It is also provided
with suitable side walls. Opposite to the electrode i may be a wall or abutment j.
Mounted in the electrode c are a number of pencils or cartons of which those
designated are longer than those designated ¹ or at any rate the pencils k protrude
further then the others for purposes to be presently described. The number of
carbons in each set is not important and may be varied. As shewn in the drawings,
there are four long or protruding pencils, and twelve short pencils k¹. Pro-
vision is made for controlling the electrical conditions of the circuit. For example I
have shewn a shunt wound dynamo f whose field coils are connected in series with a
rheostat f¹.
Coke or refuse calcium carbide in limited quantity as shewn at A, is placed in the
hopper in order to protect the plate forming the electrode i and the pencils kare
brought into contact with the plate like part of the electrode i thus completing the
circuit f, g, b, i, k, c, g', (see Figure 1). Since the pencils k are longer than the
pencils the circuit is closed through the former only. Carbon ground so as to pass
for example through a forty mesh, is inserted into the hopper until it is one third
full, more or less. This underlying layer of carbon is designated l.
A mixture m,
containing carbon and calcium generally in the form of lime is then put on top of
the layer of carbon, and a top layer of broken coke or bricks, stones and the like
as n about a foot thick is placed upon the mixture of carbide producing materials m.
The electrode c is now moved toward the right, or in other words away from the
electrode i, and there is maintained a current of for example a thousand amperes at
the long pencils or carbonsk, which may be sixty four inches in cross section. This
gives rise to the rapid production of a thin shaft or core or conducting path of

page_text: و"
ог
calcium carbide which is impure or incomplete in that it contains a large quantity
of fused lime which will absorb carbon slowly, it being understood that the electrodes
are gradually separated during its formation. Upon the completion of a shaft or
core or conducting path of the required length, the pencils or carbons are forced
back (that is toward the left in the drawings) into the mass of carbide and unfinished
mixture far enough to complete the circuit through all the pencils, both long and
short. The current now flows from the faces of all the pencils and tends to increase
in amperage. However, I restrain such tendency in any appropriate manner, for
example, by reducing the voltage by means of the insertion of induction in the case
of alternating current or of resistance with a direct current, or the proper manipula-
tion of the exciting current of the dynamo to about five thousand amperes. As shewn
in Figure 1 the voltage may be reduced for this purpose by increasing the resistance
in the field of the shunt wound dynamo by means of the rheostat. The carbide
shaft or
teazer" is a good conductor and remains incandescent, thus causing the
particles of the carbide producing mixture m which lie in a zone surrounding it, to
be chemically combined so that the mass of calcium carbide does not increase in
length but does increase or grow in diameter concentrically. Since the "teazer
shaft is a good conductor and since it is made to carry an excessive current, it follows
that the current flowing through it keeps it hot. It may be remarked that through
these operations, the top layer or coke n permits the gases generated to escape
through it, but it retains the carbide producing material and prevents it from being
thrown out at the top so that a saving is effected. Moreover, the furnace being
properly charged, no further stoking is necessary because the mass of carbide of
calcium increases in diameter as has been explained and this absence of stoking is
obviously a desirable feature. Moreover, the pencils require no further movement
until the completion of the operation upon the charge, so that the attendant may
devote his time to other useful things. Since the carbon pencils k, k, are completely
embedded at all times they are not exposed to the air and therefore are not con-
sumed or burned and last a comparatively long time. The carbon strewn upon the
floor of the furnace and constituting the layer is of course, brought into contact
with the diametrically growing mass of calcium carbide, which contains considerable
free molten lime and nascent calcium, and the latter absorbs this carbon chemically
as does also, the highly heated calcium carbide and thus produces calcium carbide
containing the maximum amount of carbon, i.e. as much carbon as the calcium can
combine with. Such carbide of calcium is not necessarily crystalline like normal
carbide and I have found that from it may be produced from six to six and two-
tenths cubic feet of acetylene gas to the pound, whereas normal crystalline carbide of
calcium I have found to produce not more than five and five-tenths cubic feet of
acetylene gas to the pound. While I have spoken of the described calcium carbide
which contains the maximum amount of carbon as not being crystalline, still I desire
it to be understood that such carbide may and sometimes does, contain particles of
crystalline carbide. Upon the completion of the treatment of the material contained
in one hopper it may be removed and replaced by another hopper and the finished
product may be dumped from its containing hopper.
Having particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The herein described process which consists in forming a core or conducting
path of calcium carbide and molten lime ready to take up carbon in the presence of
free carbon by means of a current of electricity passing between electrodes, and then
increasing the working cross section of one of said electrodes and maintaining said
core or conducting path incandescent by a regulated increase of current to cause it
to take up carbon and to form carbide concentrically around it substantially as
described.
2. The herein described process which consists in forming a core or conducting
path of calcium carbide and molten lime ready to take up oarbon in the presence of

page_text: free pulverulent carbon by means of a current of electricity passing between
electrodes, and then maintaining said core or conducting path incandescent by a
regulated increase of current to cause it to take up carbon and to form carbide
concentrically around it, substantially as described.
3. In combination an electric furnace having a platelike electrode, pencils or
carbons of which some protrude beyond the others and all of which make up the
second electrode, means of shifting one of said electrodes to close circuit through
the protruding pencils and subsequently through all the pencils, and circuit connections
and their controlling devices, substantially as described.
4. In combination a furnace having its terminal plate as b, connected in circuit,
a detachable hopper having one of its conducting walls adapted to rest on and form
electrical contact with said plate, a horizontally adjustable electrode having circuit
connections, and means for shifting the last mentioned electrode, substantially
as described.