Improvements in the Concentration or Vaporization of Sulphurio and Acetic Acids, and in Apparatus therefor.
Year: 1893

page_text: [Date of Application, 23rd Dec., 1893-Accepted, 27th Jan., 1894
COMPLETE DE MULTICA
Improvements in the Concentration or Vaporization of Sulphurio
and Acetic Acids, and in Apparatus therefor.
A communication from STANLEY COOPER PEUCHEN, of 393, Sackville Street,
City of Toronto, County of York, Dominion of Canada, Manufacturer, and
PETER CLARKE, of 11, Washington Avenue, Toronto, aforesaid, Gentleman.
I, ALFRED JULIUS BOULT of 323 High Holborn 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 ascer-
tained in and by the following statement :-
The object of the invention is-first, to devise a process of concentrating or
vaporizing sulphuric and acetic acids by which the heat can be applied immediately
to the liquid and be at all times under the control of the operator and by which
impurities in the acid will be precipitated during the operation; second to devise
suitable apparatus therefor. These objects are accomplished by passing through
the acid in electric current from acid proof electrodes of high electrical resistance
either held stationary or arranged so that they may be revolved in the liquid, the
whole being arranged in detail substantially as hereinafter more particularly
described.
Figure 1 is a sectional elevation of the apparatus used in this improved process.
Figure 2 is an enlarged detail of one of the arms carrying the electrodes shown
in Figure 4.
Figure 3 is an enlarged detail showing the construction of one of the shaft
bearings and one of the wire connections.
Figure 4 shows a preferable method of carrying revolving electrodes.
Figure 5 shows an alternative arrangement of the electrodes by which a separate
still or retort may be dispensed with.
The present methods of condensing or vaporizing these acids require the use of
outside heat which renders it impossible to use glass retorts, they being almost
invariably broken by unequal expansion or the weight of the acid. In consequence
of this, expensive retorts of platinum are necessitated, especially in the condensation
of sulphuric acid as it comes from the chamber; nor when so condensed are any
impurities eliminated.
When putting this process into operation, the sulphuric acid is taken as it comes
from the chamber and placed in a glass retort suitably supported and having a pair
of acid-proof electrodes of high resistance placed therein, which are preferably
carried by a porcelain stand and connected by platinum wires to the poles of a
dynamo or battery (see Figure 1). The current is then turned on and the electrodes
become intensely heated, vaporizing the water mixed with the acid, at the same
time the current flowing through the liquid between the electrodes decomposes and
precipitates the impurities contained in the acid, such as sulphate of lead etc.
When the acid is sufficiently concentrated, the current, which is preferably a large
current of low voltage, is turned off and the contents of the still removed.
In vaporizing the acid, the process is precisely the same, with the exception that
the retort or still is connected with a suitable condenser and more current in
ampères is required.
When operating on acetic acid, a copper still, such as shown in Figure 4 niay be
used, but my correspondents do not confine themselves when working by their
process to the use of any particular metal nor to any particular arrangement of the
electrodes, which may be stationary as shown in Figure 1 or arranged to revolve
and agitate the liquid as shown in Figure 4, or may be arranged as shown in

page_text: .
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Figure 5, in which one of the electrodes is made to take the place of the still.
This electrode may be V-shaped in section as shown or may be hemi-spherical or
tubular. The acid flows between the electrodes and is concentrated and purified
during its passage.
Having described this process, I will now set out the construction of the apparatus
used therein when revolving the electrodes having reference to the accompanying
drawings, in which :—
A is a still having a hollow shaft B extending through it, which shaft is
supported in suitable bearings C hereinafter more particularly described. Each
end of the shaft is reamed out and a metal terminal D inserted therein which
terminal is insulated from the shaft and is connected to an insulated conducting
wire E.
F is a contact piece preferably formed as a screw and supported by a suitable
standard. This contact piece is connected with the dynamo supplying the current
and bears against the terminal D, as indicated.
Arms G, formed in two parts, as shown in Figure 3, are clamped around the
shaft and carry, clamped between their ends electrodes H and I formed of carbon
or other suitable material.
The electrodes H are connected by insulated wires embedded in insulating
material clamped between the two halves of the carrying arms to the wire E,
leading from one pole of the dynamo the wire from the carbon passing through a
transverse hole leading to the central hollow of the shaft.
The electrodes I are similary connected with a wire entering from the other end
of the shaft and connected with the opposite pole of the dynamo.
When a current is caused to flow through the wires E, the electrodes H and I
are intensely beated owing to the resistance they offer to the passage of the current
which passes from one to the other through the intervening liquid.
In Figure 4 six pairs of electrodes are shown arranged about the shaft B but of.
course any number may be employed. On the ends of the shaft outside the still,
suitable driving pulleys are arranged whereby the shaft B, may be revolved; the
arms carrying the heated electrodes are thereby revolved in the liquid thoroughly
agitating it and at the same time imparting heat to it in a very effective manner.
The bearings C before referred to are preferably constructed as follows:-
A tube J is inserted through the end of the still and firmly clamped thereto by
means of the jamb-nuts K which clamp the metal of the still A between the washer L
and the head M of the tube J the joints being packed with plumbago and rubber or
other suitable material. A suitable bushing N is placed around the shaft inside of
the tube J and is tightened around the shaft when desired by means of the stuffing
nut 0; the bushing being held in place by the flange P and graphite washer Q.
By the above construction a tight and acid-proof bearing is secured which is very
important to ensure the proper working of the apparatus.
The shaft B has been described as revolvable, but it will readily be seen that the
contents of the still will be very effectually heated if the shaft be rigidly connected
to the still.
It is not essential that the shaft be journalled at both ends as one bearing would
be sufficient especially in a small still to carry the shaft.
When heating acid in a glass retort it is preferred to use stationary carbon plates
either held in the manner above described or in any other suitable way.
From the above description it will be seen that my correspondents have invented
a process for the concentration or vaporization of acids which is more cconomical
than any process now in use and which results in the production of a purer acid,
and also that they have devised very effective apparatus for use in the game.
Having now particularly described and ascertained the nature of the said iuven-
tion as communicated to me by my foreign correspondents, and in what manner the
same is to be performed, I declare that what I claim is :--
1. An improved process for the concentration or vaporization of sulphuric and

page_text: acetic acids which consists in subjecting the acid to the action of an electric current
passing between acid proof electrodes of high resistance substantially as and for the
purpose specified.
2. A pair of acid proof electrodes of high resistance placed at a suitable distance
apart one of them being so shaped as to hold the acid which is caused to flow
between them substantially as and for the purpose specified.
3. An improved process for the concentration or vaporization of sulphuric and
acetic acids which consists in placing the acids to be operated on in a retort and
subjecting it to the action of an electric current passing between acid-proof
electrodes of high resistance carried on arms arranged on a shaft revolving in the
acid substantially as and for the purpose specified.
4. A still baving a hollow shaft extending across it and a pair of arms projecting
therefrom in combination with insulated conducting wires arranged within the said
shaft and connected with electrodes of carbon or other suitable material supported
by and insulated from said arms substantially as and for the purpose specified.
5. A still having a hollow shaft extending across it suitably journalled in the
ends of the still and adapted to be driven by any suitable means and having a pair
of arms projecting therefrom in combination with insulated conducting wires.
arranged within the said shaft and connected with electrodes of carbon or other
suitable material supported by and insulated from said arms substantially as and
for the purpose specified.
6. A still having a hollow shaft extending into it and a pair of arms projecting
therefrom in combination with insulated conducting wires arranged within the said
shaft and connected with electrodes of carbon or other suitable material supported
by and insulated from said arms substantially as and for the purpose specified.
7. A still having a hollow shaft extending into it suitably journalled in one end
of it and adapted to be driven by any suitable means and having a pair of arms.
projecting therefrom in combination with insulated conducting wires arranged
within the said shaft and connected with electrodes of carbon or other suitable
material supported by and insulated from said arms substantially as and for the
purpose specified.
8. A still having a series of electrically heated plates of carbon or other suitable
material supported therein by arms attached to a revolvable shaft journalled on the
still substantially as and for the purpose specified.
9. The combination of the still A shaft B bearing box or tube J nut K and
bushing N substantially as and for the purpose specified.
10. The combination of the still A shaft B bearing box or tube J nut K and
bushing N carbon or graphite washer Q and stuffing nut O substantially as and for
the purpose specified.
11. The combination of the still A. shaft B insulated conducting wire E insulated
terminal D and suitably supported contact piece F substantially as and for the
purpose specified.
Dated this 01st dose of December 1902