An Electrolytic Process for the Preparation of a Liquid for Bleaching Fabrics, Paper Pulp, and other matters.
Year: 1890

page_text: Date of Application, 23rd Apr., 1890
Complete Specification Left, 19th Jan., 1891-Accepted, 14th Mar., 1891
PROVISIONAL SPECIFICATION.
An Electrolytic Process for the Preparation of a Liquid for Bleaching
Fabrics, Paper Pulp, and other matters.
I, SERGIUS STEPANOW, Counsellor of the College of St. Petersburg in the
Empire of Russia, do hereby declare the nature of this invention to be as
follows:-
The process, the subject of this Specification, consists essentially in causing a
current of electricity to pass through a solution of common salt (chloride of sodium)
to which a small quantity of quicklime is added. The re-action which takes place
may be expressed by the following formula :-
Whilst the other natt remaTIS HI SOILETON,
The addition of lime gives to the proposed process the following advantages as
compared with other electrolytic processes for the preparation of bleaching
liquids.
1. Escape of chlorine into the air is entirely avoided whereas ordinarily this
occurs at the commencement of the operation before a sufficient quantity of alkali is
formed in the liquid.
2. The opposing electro motive force resulting from the reaction described never
exceeds 1.8 volts, whereas in the magnesia process (precédé Hérmite) it amounts
almost to 4 volts.
3. The chloride of lime (Ca(C10),) formed by the proposed process resists better
the action of the current which easily transforms the corresponding salt of soda
into chlorate, thus in decomposing the solution of chloride of sodium without the
addition of lime the quantity of hypochlorite of soda (NaCIO) can never become
greater than three or four grammes per litre of liquid whilst the process now
proposed will yield a solution of bleaching salt saturated to a degree quite sufficient
for all practical purposes (14 to 16 grammes of salt per litre of liquid).
The annexed drawings show by way of example the arrangements of an apparatus
suitable for putting my invention into practice.
Figure 1 represents the apparatus in side elevation and vertical section.
Figure 2 is a plan of it, and
Figure 3 a transverse section.
The apparatus consists of a wooden or cast iron frame with inclined sides or ramps a
upon which are fixed by means of iron stems the porcelain insulators which
support iron frames ce suspended from them. In each of the frames c c (in the
apparatus represented there are 20 of these frames) a leaden vessel d is placed
(530 long, 45m wide, and 250 / high in the apparatus which I have
constructed) having at its upper part a lip or spout by which the liquid submitted
to electrolysis passes successively from vessel to vessel and so flows through the
entire length of the apparatus. The leaden vessels also form the negative electrodes
of the battery or separate elements of the apparatus. The positive electrodes are
thin sheets of platinum e e e (400 mm by 200 mm) soldered to a copper rod e¹ the
ends of which are supported in glass cups ff 9 y, let into the thickness of the
ID017

page_text: ramps a a, of the frame.
At one of the ends of the copper rods.the cups ff (from
15 to 20 deep) are just sufficiently wide to admit the end of the rod e¹ and only
serve to insulate the positive electrode from the frame and at the same time to
prevent the lateral displacement of the copper rod. At the other end of each rod
the cups, whilst of the same depth as before have a larger diameter (from 15 to
20mm) and are full of mercury. Each of the cups receives the ends of the
conducting wires from the platinum electrode of the corresponding element and
from the leaden electrode of the next element arranged beneath.
The electric current produced by the dynamo electric machine enters the
platinum electrode of the lowest element, passes through the liquid to the walls of
the leaden vessel of this element then by the conducting wire it passes to the
platinum electrode of the next element &c.
At the same time the saline solution to be subjected to electrolysis is led from a
corresponding cistern by the pipe or passage i into the highest of leaden vessel d
(at the top of the battery) passes into the next element (arranged beneath) by the
spout fixed upon the first vessel d at the opposite end (relatively to the admission
pipe) and so on. In this manner the liquid is obliged to pass the whole length of
each vessel; it is submitted in every part to the action of the current and finally
reaches the lowest vessel completely transformed. In this state the solution is
conveyed into a receiver or basin which may serve for several apparatus of the same
sort.
To obtain a more intimate mixture of the liquid and consequently a more complete
electrolytic action, the liquid from each vessel is made to flow, not directly upon
the surface of the liquid in the next vessel, but it is made to flow first into a glass
cylinder placed in the leaden vessel and terminating at a distance of 50" or
thereabout from the bottom of the vessel. In this manner the flow of the liquid is
made to traverse the whole mass of the solution contained in the vessel.
Dated this 23rd day of April 1890
7101
CARPMAEL & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Electrolytic Process for the Preparation of a Liquid for Bleaching
Fabrics, Paper Pulp, and other Matters.
1, SERGIUS STEPANOW, Counsellor of the College of St. Petersburg in the
Empire of Russia, 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:-
The process, the subject of this Specification, consists essentially in causing a
current of electricity to pass through a solution of common salt (chloride of
sodium) to which a small quantity of quicklime is added. A solution containing
7 per cent. of common salt and 3 of a per cent. of lime is suitable. The re-action
which takes place may be expressed by the following formula :-
2Ca(HO), + 4NaCl + 2H2O = CaC₁₂ + Ca(CIO)2 + 4NaHO + 4H.
Half of the quantity of caustic soda formed by this re-action transforms the
chloride of calcium into quicklime and causes it to precipitate
(2NaHO + CaC₁₂ = 2NaCl + Ca(HO)₂);
=
whilst the other half remains in solution.
The addition of lime gives to the proposed process the following advantages
as compared with other electrolytic processes for the preparation of bleaching
liquids.
1. Escape of chlorine into the air is entirely avoided whereas ordinarily this

page_text: occurs at the commencement of the operation before a sufficient quantity of
alkali is formed in the liquid.
2. The opposing electro motive force resulting from the reaction described
never exceed 1.8 volts, whereas in the magnesia process (precédé Hérmite) it
amounts almost to 4 volts.
3. The chloride of lime. (Ca(CIO),) formed by the proposed process resists
better the action of the current which easily transforms the corresponding salt
of soda into chlorate, thus in decomposing the solution of chloride of sodium
without the addition of lime the quantity of hypochlorite of soda (NaClO) can
never become greater than three or four grammes per litre of liquid whilst the
process now proposed will yield a solution of bleaching salt saturated to a
degree quite sufficient for all practical purposes (14 to 16 grammes of salt per
litre of liquid).
The drawings left with the Provisional Specification show by way of example
the arrangements of an apparatus suitable for putting my invention into
practice.
Figure 1 represents the apparatus in side elevation and vertical section.
Figure 2 is a plan of it, and
Figure 3 a transverse section.
The apparatus consists of a wooden or cast iron frame with inclined sides or
ramps a upon which are fixed by means of iron stems the porcelain insulators >> b
which support iron frames cc suspended from them. In each of the frames cc (in
the apparatus represented there are 20 of these frames) a leaden vessel d is placed
(530 long, 45 mm wide, and 250 /m high in the apparatus which I have con-
structed) having at its upper part a lip or spout by which the liquid submitted to
electrolysis passes successively from vessel to vessel and so flows through the entire
length of the apparatus. The leaden vessels also form the negative electrodes of
the battery or separate elements of the apparatus. The positive electrodes are
thin sheets of platinum e e e (400 mm by 200 /m) soldered to a copper rod e¹ the
euls of which are supported in glass cups, gg, let into the thickness of the
ramps a a of the frame. At one of the ends of the copper rods the cups fƒ (from
15 to 20 deep) are just sufficiently wide to admit the end of the rod e¹ and only
serve to insulate the positive electrode from the frame and at the same time to
prevent the lateral displacement of the copper rod. At the other end of each rod
the cups, whilst of the same depth as before have a larger diameter (from 15
to 20 ) and are full of mercury. Each of the cups gy receives the ends of the
conducting wires from the platinum electrode of the corresponding element and
from the leaden electrode of the next element arranged beneath.
The electric current produced by the dynamo electric machine enters the platinum
electrode of the lowest element, passes through the liquid to the walls of the leaden
vessel of this element then by the conducting wire it passes to the platinum
electrode of the next element &c.
At the same time the saline solution to be subjected to electrolysis is led from a
corresponding cistern by the pipe or passage i into the highest of leaden vessel d
(at the top of the battery) passes into the next element (arranged beneath) by the
spout fixed upon the first vessel d at the opposite end (relatively to the admission
pipe) and so on. In this manner the liquid is obliged to pass the whole length of
each vessel; it is submitted in every part to the action of the current and finally
reaches the lowest vessel, completely transformed. In this state the solution is
conveyed into a receiver or basin which may serve for several apparatus of the same
sort.
To obtain a more intimate mixture of the liquid and consequently a more com-
plete electrolytic action, the liquid from each vessel is made to flow, not directly
upon the surface of the liquid in the next vessel, but it is made to flow first into a glass
cylinder placed in the leaden vessel and terminating at a distance of 50 or
thereabout from the bottom of the vessel. In this manner the flow of the liquid is
made to traverse the whole mass of the solution contained in the vessel.

page_text: 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 simultaneous employment of chloride of sodium and lime in the process of
the preparation of bleaching liquid by way of electrolysis.
2. Apparatus to be used in carrying on the process, in which as represented in
the annexed drawings the liquid flows from vessel to vessel and is progressively
treated as herein set forth.
Dated this 7th day of January 1891
CARPMAEL & Co.,
Agents for the Applicant.