Improvements in and relating to Electrical Furnaces, more particu- larly applicable for the Production of Calcium Carbide.
Year: 1898

page_text: Date of Application, 25th June, 1898
Complete Specification Left, 21st Apr., 1899-Accepted, 20th May, 1899
PROVISIONAL SPECIFICATION.
Improvements in and relating to Electrical Furnaces, more particu-
larly applicable for the Production of Calcium Carbide.
We, WILLIAM LANG DURBAN, of 43, Park Road, South Tottenham, London,
Chemist, and JOHN GORE, of Vernan Villa, Park Street, Trowbridge, Wilts,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
-
Our invention relates to that construction of electrical furnaces for the produc-
tion of calcuim carbide, and for other purposes, in which the necessary heat is
produced by the incandescence of a carbon conductor held between the ends of two
electrodes to which the electrical energy is supplied from any suitable source.
According to our invention we construct such furnaces as follows.
The furnace proper consists of a trough shaped chamber built up of slabs of
refractory material which are held together at the ends by metal frames of a
trough section into which the end slabs fit, and which are tied together by longitu-
dinal tie-rods. At intervals the sides of the chamber are supported by these rods
by means of bolts passing through notched holes in the slabs, having heads on the
inner side and screwing into nuts on the outer side, formed with eyes through
which the tie rods pass, with the intervention of an insulating lining. The rods
and their screw nuts are also insulated from the end frames through which
they pass.
The end frames carry at their middle rotatable threaded bushes, through which
screw two screw spindles the inner ends of which carry metal sockets into which
are fitted the ends of the two electrodes, that are preferably made of cylindrical or
polygonal form. The said screwed bushes are fixed to toothed wheels with which
gear toothed pinions fixed on a shaft extending longitudinally outside the furnace
from the one end frame to the other. By means of this arrangement it will he scen
that an operator situated at one end of the furnace can, by the rotation of the
said shaft in one direction or the other, simultaneously rotate the screwed bushes
so as to cause both screw spindles with their electrodes either to approach towards
or to recede from each other.
In operating with this construction of furnace, the operator first moves the
electrodes from each other, so as to allow of the introduction of the conducting
rod between them, preferably near the uppermost part thereof. after which he
turns the gearing so as to approach the electrodes sufficiently to hold the carbon
rod firmly between them.
The
The trough of the furnace having been filled right up to the top with the
materials for producing calcium carbide, the electric current is passed into the elec-
trodes through screw terminals fixed on the metal sockets of the latter.
carbon rod being heated to incandescence by the passage of the current, the
calcuim carbide is formed and becomes deposited thereon as a cylindrical sheathing.
This is continued until a sufficient deposit has formed and the carbon rod has
become more or less consumed so as to interfere with the proper action. The

page_text: calcuim carbide thus formed is then removed from between the electrodes, which is
preferably facilitated by tilting up the free end of the one electrode slightly in
order to break off the firmly adhering end of the carbide.
For this purpose we support the ends of the electrodes upon a roller carried
by an inclined arm on a shaft passing out through the side of the furnace and
provided outside with a hand fever, so that by moving the latter the arm is
raised and thereby tilts up the electrode. For enabling the tilting motion to be
effected, the socket of the electrode is preferably connected to the supporting spindle
by a ball and socket joint.
The heat produced by the current passing through the rod connecting the elect-
rodes being greatest at the point of contact between them, the electrode necessarily
becomes burnt way to some extent at that point. In order to obviate the necessity
of cutting away the face of the electrode for producing a fresh contact surface
thereon, we arrange the electrodes so that they can be turned round with their
sockets upon the screw spindles, so that after the formed carbide has been removed
they are turned round through a certain angle so as to bring an unattacked
portion of their end surface uppermost for securing the next carbon rod to be
inserted, this being repeated until the whole of the end surfaces of the electrodes
have been brought into operation.
To facilitate such turning the electrode sockets are provided with a corre-
sponding number of screw terminals round their periphery for the consecutive
attachment of the electrical conductor.
In order to always maintain the carbon rod at about the middle of the furnace,
it may be required occasionally to shift each of the electrodes in one direction
or the other independently of the other one. To enable this to be done we either
arrange the bearings of the longitudinal shaft that effects the movement of the
electrodes, so that it can be shifted laterally sufficiently to bring the pinions out
of gear with the wheels of the screwed bushes, whereupon the electrodes can be
shifted backwards or forwards independently by their screw spindles. Or the
pinions may be arranged to slide longitudinally upon their shaft to bring them
out of gear.
Although we prefer to make the electrodes cylindrical or polygonal and rotatable
as described, yet they may also be of rectangular shape, in which case, if the
furnace is supplied with a powerful current, two or more of the incandescence rods
may be arranged side by side between the electrodes so as to operate simul-
taneously for the production of carbide.
Dated this 25th day of June 1898.
ABEL & IMRAY,
Agents for the Applicants.
Improvements in and relating to Electrical Furnaces, more particu-
larly applicable for the Production of Calcium Carbide.
We, WILLIAM LANG DURBAN, of 13, Park Road, South Tottenham, London,
Chemist, and JOHN GORE, formerly of Vernan Villa, Park Street, Trowbridge,
Wilts, but now of 17, Vale Road, Sutton, Surrey, Mechanical Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
Our invention relates to that construction of electrical furnaces for the produc-
tin of calcium carbide, and for other purposes. in which the necessary heat is

page_text: produced by the incandescence of a carbon conductor held between the ends of two
electrodes to which the electrical energy is supplied from any suitable source.
According to our invention we construct such turnaces as we will describe with
reference to the accompanying drawings in which Fig. 1 shows a part side
elevation and part longitudinal section, Fig. 2 an end view, Fig. 3 a part sectional
plan and Figs. 4, and 6 enlarged details.
The furnace proper consists of a trough-shaped chamber a, built up of slabs b
of refractory material which are held together at the ends by metal frames c of
a trough section into which the end slabs fit, and which are tied together by
longitudinal tie rods d. At intervals the sides of the chamber are supported by
these rods by means of bolts e, Fig. 6, passing through notched holes in the slabs 6,
and having heads on the inner side and screwing into nuts f on the outer side,
formed with eyes through which the tie rods pass, with the intervention of an
insulating lining g, of asbestos or other material. The rods and their screw nuts
are also insulated from the end frames through which they pass by linings h.
The end frames chave fitted therein refractory slabs i enclosing the ends of
the chamber a and the frames carry at their middle rotatable threaded bushes j,
through which screw two screw spindles having respectively right and left
handed threads, the inner ends of which spindles carry metal sockets into which
are fitted the ends of the two electrodes m m, that are preferably made of cylindrical
or polygonal form. The said screwed bushes are fixed to toothed wheels n with
which gear toothed pinions o fixed on a shaft extending longitudinally outside
the furnace from the one end frame to the other. By means of this arangement
it will be seen that an operator situated at one end of the furnace can, by the
rotation of the said shaft p in one direction or the other, simultaneously rotate the
screwed bushes j so as to cause both screw spindles with their electrodes either
to approach towards or to recede from each other.
In operating with this construction of furnace, the operator first moves the
electrodes m m from each other, so as to allow of the introduction of the conducting
rod I between them, preferably near the uppermost part thereof, after which he
turns the gearing so as to approach the electrodes m sufficiently to hold the carbon
rod firmly between them.
The trough of the furnace having been filled right up to the top with the
materials for producing calcium carbide the electric current is passed into the
electrodes through screw terminals fixed on the metal sockets 7 of the latter.
The carbon rod q being heated to incandescence by the passage of the current, the
calcuim carbide is formed and becomes deposited thereon as a cylindrical sheathing.
This is continued until a sufficient deposit has formed, the carbon rod becoming
gradually consumed.
The calcium carbide thus formed is then removed from between the electrodes,
which is preferably facilitated by tilting un the free end of the one electrode
slightly in order to break off the firmly adhering end of the carbide.
For this purpose we support the ends of the electrodes upon a rollers carried
by an inclined arm on a shaft carried in suitable brackets and passing out
through the side of the furnace being provided outside with a hand lever u, so
that by moving the latter the arm is raised and thereby tilts up the electrode. For
enabling the tilting motion to be effected the socket 7 of the electrode is pre-
ferably connected to the supporting spindle k by a ball and socket joint r, the
spindle being insulated from the socket by asbestos or other lining at c r.
The heat produced by the current passing through the rod g connecting the
electrodes m'm being greatest at the point of contact between them, the electrode
necessarily becomes burnt away to some extent at that point. In order to obviate
the necessity of cutting away the face of the electrode for producing a fresh
contact surface thereon, we arrange the electrodes so that they can be turned round
with their sockets upon the screw spindles & (this being readily done by means of
the ball and socket joint) so that after the formed carbide has been removed they
are turned round through a certain angle so as to bring an unattacked portion of

page_text: their end surface uppermost for securing the next carbon rod to be inserted, this
being repeated until the whole of the end surfaces of the electrodes have been
brought into operation.
To facilitate such turning, the electrode sockets are provided with a correspond-
ing number of screw terminals round their periphery for the consecutive
attachment of the electrical conductor.
In order to always maintain the carbon rod at about the middle of the furnace,
it may be required occasionally to shift each of the electrodes in one direction
or the other independently of the other one. To enable this to be done we either
arrange the bearing y of the longitudinal shaft that effects the movement of the
electrodes with slots as at y so that the shaft can be shifted laterally sufficiently
to bring the pinions o out of gear with the wheels n of the screwed bushes, where-
upon the electrodes can be shifted backwards or forwards independently by
their screw spindles. Or the pinions o may be arranged to slide longitudinally
upon their shaft to bring them out of gear for the above purpose.
Although we prefer to make the electrodes cylindrical or polygonal and
rotatable as described, yet they may also be of rectangular shape, in which case
if the furnace is supplied with a powerful current, two or more of the incandesence
rods q may be arranged side by side between the electrodes so as to operate simul-
taneously for the production of carbide.
We are aware that electrical furnaces have already been constructed of a trough
shape formed of slabs of refractory material, and containing two opposite hori-
zontal electrodes and an interposed carbon conductor, the electrodes being advanced
towards each other by screw spindles, and we make no general claim to such an
arrangement.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what
we claim is:-
1. In electrical furnaces of the kind herein referred to, the combination with
two electrodes such as m, supported by lever arms such as t and connected to
screw spindles such as having respectively right and left handed screw threads
screwing through threaded bushes in frames at the ends of the furnace, which
bushes are both connected by suitable gear to the same shaft extending from
one end of the furnace to the other, so that on rotating the said shaft the two
electrodes are caused simultaneously to advance towards or recede from each
other, substantially as herein described.
2. In combination with an electrical furnace such as is referred to in the first
claim, connecting the sockets / carrying the electrodes to the screw spindles k by
ball and socket joints, and arranging the lower arms t supporting the electrodes
to be rocked by means of outside hand levers, for the purpose of detaching the
formed bar of calcuim carbide therefrom, substantially as described.
3. In combination with an electrical furnace such as is referred to in the first
claim, connecting the two end frames which hold the refractory slabs by
means of tie rods which are also connected to the sides of the furnace by
bolts e and eye nuts f with insulating linings g, substantially as and for the
purpose described.
1
011
11200
ABEL & IMRAY,
Agents for the Applicants.