Year: 1887

page_text: We EUGENE HERMITE, EDWARD JAMES PATERSON, and CHARLES FRIEND COOPER,
all of European Works, Pownall Road, Dalston in the County of Middlesex, Engineers,
do hereby declare the nature of this invention to be as follows:-
In the Specifications No. 13,929 of 1884 is described a method of bleaching by
treating the material to be acted on with a solution of magnesium chloride which
subjected to electrolytic action. In applying this method, it is found best to place in
communication with the bleaching tanks or vessels, another vessel through which the
bleaching liquor is caused to circulate, this vessel containing the electrodes, which
are connected to a dynamo-electric machine or other source of electricity. The liquor
in passing through this vessel is electrolysed, it goes to the bleaching tanks where it
acts on the material under treatment, it returns to the electrolysing vessel to be again
electrolysed, and so on continuously, without waste except of such small quantity of
liquid as is taken away by the moist material.
Our invention relates to the construction of the electrolysing apparatus in such a
manner as to render it effective by exposing large and clean surface to the circulating
liquid, and readily accessible for repair or for varying the degree of the electrolysing
influence. For the positive electrodes we use a number of thin sheets of platinum
stiffened at their edges by non-conducting material, or they may be plates having
their surfaces coated with platinum as foil or as deposit on them. Between the sheets
of platinum we arrange the negative electrodes consisting of sheets of zinc. As the
zinc is liable to receive on it deposit from the electrolysed liquid, we provide for
cleansing its surface in several ways. One way is to make the zinc in the form of
dises fixed on shafts caused to revolve slowly while knives or scrapers are pressed by
weights or springs against the surfaces of the discs. According to another arrange-
ment, the zinc discs remain stationary while scrapers are caused to revolve in contact
with their surfaces. Instead of making the zinc surfaces in the form of discs, they
may be in the form of cylinders slowly revolving while the scrapers bear against them,
and in that case the platinum sheets are hent into circular form so as to surround at a
little distance the zinc cylinders. Or, again, the cylinders of zinc, instead of revolving,
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page_text: may be caused to reciprocate to and fro within tubes of platinum of larger diameter,
while stationary scrapers bear against the zinc surfaces. In all cases, we arrange the
platinum and zinc surfaces near each other, but at sufficient distance to allow a flow
of liquid between them, and we prefer to ensure the circulation by suitable pumps.
When the zinc discs or cylinders are made to revolve or reciprocate as above
described, their connection with the electrical conductor is made by brushes or rubbers.
In the electrolysing vessel and pipes communicating with it no metal other than zinc
or platinum is employed, generally the vessel itself and the pipes are best made of
ceramic or such like material.
Dated this 8th dove of Bahru 1887

page_text: We, EUGENE HERMITE, EDWARD JAMES PATERSON, and CHARLES FRIEND COOPER,
all of European Works, Pownall Road, Dalston, in the County of Middlesex, Engineers
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:-
In the Specification No. 13929 of 1884 is described a method of bleaching by
treating the material to be acted on with a solution of magnesium chloride which is
subjected to electrolytic action. In applying this method, it is found best to place in
communication with the bleaching tanks or vessels, another vessel through which the
bleaching liquor is caused to circulate, this vessol containing the electrodes, which
are connected to a dynamo-electric machine or other source of electricity. The liquor
in passing through this vessel is electrolysed, it goes to the bleach tanks where it acts
on the material under treatment, it returns to the electrolysing vessel to be again
electrolysed, and so on continuously without waste, except of such small quantity of
liquid as is taken away by the moist material.
Our invention relates to the construction of the electrolysing apparatus in such a
manner as to render it effective by exposing large and clean surface to the circulating
liquid, and readily accessible for repair or for varying the degree of the electrolysing
influence.
The apparatus may be varied in form, but generally it has for the positive electrodes
surfaces of of platinum, and zinc surfaces for the negative electrodes, but as the zinc
is liable to receive on it deposit from the electrolysed liquid, we provide for cleansing
its surface either by moving it over stationary scrapers or by moving scrapers over the
stationary zinc. We will describe several modified forms of apparatus according to
our invention, referring to the accompanying drawings.
Fig. 1 is a side view and Fig. 2 is a plan shewing a complete electrolysing
apparatus.
Fig. 3 is a transverse section and Fig. 4 is a longitudinal section (both of these
figures being to an enlarged scale) of the electrolysing cell.
Referring to Figs. 1 and 2 shewing the general arrangement of the apparatus, A is
tank which receives from the bleaching vats the liquor to be electrolysed, and
supplies them with liquor when it has been electrolysed. B is a rotary pump which
draws liquor from the tank A, and sends it into the lower part of the electrolysing
cell C, from the upper part of which the liquor flows back to the tank A, the liquor
eing thus kept circulating through the cell C until it is sufficiently electrolysed.
O is a dynamo-electric machine from the terminals of which suitable insulated
onductors lead to the positive and negative plates in the cell C, as we will presently

page_text: describe. We have shewn the pump B and a shaft E, for driving the zinc discs as
being connected together by bands acting on pullies so that all are driven together
from one motor, but, obviously, they might be driven separately. Such being the
general arrangement of the apparatus, we will now proceed to describe more particularly
the construction of the electrolysing cell C and of the positive and negative elements
which are immersed in the liquor contained in the cell. Referring to Figs. 3 and 4,
the liquor enters the cell through lateral perforations of a pipe F which communicates
with the discharge of the pump B and extends along the bottom of the cell. The
liquor after rising through the spaces between the positive and negative elements,
overflows into side channels G and passes to an end channel H. and thence by a
descending pipe to the suction of the pump B. The cell C is partly divided by a
central longitudinal partition I, which however leaves sufficient passage above and
below for the circulation of the liquor through the two compartments of the cell. In
each of these compartments, there is a shaft K journalled in end bearings, both these
shafts being caused to revolve slowly by worm wheels on them gearing with worms on
the cross shaft E. The shafts K have fixed on them the zinc discs L, and between
each pair of these discs is placed one of the platinum or platinised plates M. Each
of these plates M is held in a frame from one of the upper angles of which projects
upwards an arm N with a bolt projecting from it horizontally. At each side of the
. cell is fixed a rack P which is insulated from the cell and from the structure generally
but is electrically connected by rods Q (see Figs. 1 and 2) to one of the terminals of
the dynamo-electric machine D; in each of the notches of the racks P a bolt of one of
the arms N is held by nuts screwed on the bolt at each side of the rack. Thus all the
plates M are connected to one of the terminals of the dynamo-electric machine ; the
other terminal is connected directly to the metal of the cell C and is thus electrically
connected to all the zinc discs L. On the partitions are fixed inclined scrapers S,
which as the discs L revolve scrape their flat surfaces and scrape also the cylindrical
surfaces of the tubular bosses by which the discs are fixed on the shafts K and thus
clear them of deposit.
Instead of the inclined scrapers S or in addition to them, other scrapers s, may be
used, which are clastic blades fixed on the sides of the frames that carry the platinum
plates, these blades being inclined towards the zinc discs.
While the liquor by the pump B is kept in circulation through the cell C, the
electrical current produced by the dynamo-electric machine passes through the liquor
between the platinum plates M and the zinc discs Land electrolyses the liquor.
A modified form of electrolysing cell is shewn in longitudinal section by Fig. 5.
A is a tank or trough preferably made of insulating material, but it might be of
metal with suitable insulation for the platinum electrodes which are fixed in it.
a and a are the passages respectively for the inflow of the solution from the tank
or vessel in which it acts for bleaching, and for its outflow in an electrolysed
condition back to the tank or vessel. In the trough A we fix several semi-cylindrical
electrodes B; two of these are shewn, but there may be a greater number.
Each electrode B is a bent sheet of platinum or of metal plate or casting faced
internally with platinum plated or deposited on it.
All these electrodes are connected by a conductor W to one terminal of a dynamo-
electric machine or other source of electricity.
Centrally above each electrode is a shaft S journalled in stuffing boxes in the sides
of the trough A, and carrying a zinc cylinder Z of a little less diameter than the semi-
cylinder B below it, so that between each zinc cylinder and the platinum electrode
below it there is a thin semi-annular passage for the liquid.
Outside the trough A conducting brushes Care arranged to bear tangentially against
the shafts S and these bushes are connected by a conductor W to the other terminal
of the dynamo machine or other electrical generator.
Knives or scrapers K fixed in the trough A bear lightly against the surfaces of the
zinc cylinders Z. The cylinders being caused to revolve by any suitable power
applied to their shafts S, have their surfaces kept clean by the knives K and, while
the solution flows through the trough from a between the zinc electrodes Z and the

page_text: platinum electrodes D, IL Decomes electrolysed by the passage of electricity to
and returns by the passage a¹ to the tank.
The zinc surfaces, instead of being arranged so as to revolve as in the two forms of
apparatus above described, may be arranged to reciprocate as shown in Figs. 6, 7
and 8, that is to say Fig. 6 is a longitudinal section, Fig. 7 is a transverse section and
Fig. 8 is a plan of apparatus thus arranged.
Within a trough A having an inlet a and outlet a¹ for the liquor to be electrolysed
we fix on insulating supports several hollow cylinders B of which 3 are shown in the
drawings, each of these cylinders being a shell of platinum or suitable material lined
or internally plated with platinum.
Centrally within each of these cylinders a plunger C of zinc is made to reciprocate
to and fro, all these plungers being for that purpose attached to a crosshead D from
which a rod E passing through a stuffing box is linked by a connecting rod F to a
revolving crank G. Each plunger C passes through guides H armed with scrapers h
the edges of which lightly bear on the surface of the zinc. The cylinders B are
connected by a conducting wire W to one terminal of an electric generator, from the
other terminal of which a wire W₁ leads to a set of brushes K that rub on the rods E,
so as to communicate electrically with the zinc plungers C.
The liquor entering by a flowing along the trough A to a¹ through the narrow
annular spaces between the cylinders B and the plungers C, while the current of
electricity passes through it, becomes electrolysed, and the plungers C as they move
to and fro have their surfaces kept clean by the scrapers h.
The zinc surfaces may be stationary with scrapers moving over them as shewn by
the vertical section Fig. 9 and the sectional plan Fig. 10, part of which drawn to an
enlarged scale is shown by Fig. 11.
A is a hollow cylinder which may be of cast iron lined internally with platinum,
either platinum foil attached to the iron or platinum electroplated on it. To the flange
at each end of the cylinder A is fixed a cap B at the one end and B' at the other, with.
a ring C of insulating material interposed between each cap and the cylinder flange.
The caps B B are made with mouths b¹ from which circulating pipes are connected
to the tank or vessel in which the solution acts for bleaching. The caps B B' are
made with cross ribs carrying bosses D D' through which is passed a central bolt E,
and on this bolt is fixed à zinc cylinder F of such diameter as to leave a narrow
annular space between it and the outer cylinder A. On the central bolt E free to turn
thereon are fitted two sets of spokes G G which are connected together by scraping
knives or blades H that pass along the annular space between A and F. On the
spokes G is fixed a crown worm wheel K with which gears a worm on a cross
spindle L that passes through stuffing boxes of the cap B and carries a pulley / to
receive a strap for driving it from any convenient motor. To one of the caps Bor B¹
and to the cylinder A are attached conducting wires W1W connecting to the
terminals of a dynamo-electric machine or other source of electricity. The spindle L
being rotated, the scrapers H are caused to revolve scraping the surface of the zinc
cylinder F, and the solution entering and issuing by the mouths bb', as it flows
through the narrow space between A and F is electrolysed by the passage through it
of the current of electricity resulting from the connection of the platinum of A by
the wire W to the one terminal of the electric generator and of the zinc
wire W to the other terminal.
by the
Although in what precedes we have mentioned platinum or platinised surfaces as
boing suitable for the one electrode or set of electrodes in the apparatus, there are
cases in which material cheaper than platinum can be employed, especially when it
has only to transmit a moderate current of electricity.
In such cases we use pure plumbago, either natural plumbago cut to the desired
form or plumbago compressed to the form required, or glass, ceramic ware, vulcanite
or other inert nonconducting material faced with plumbago.
When plumbago is used for forming the conducting facing, it should be carefully
purified by boiling it in hydrochloric acid while chlorate of potash is added in several
dozes to the boiling mixture.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. Apparatus for electrolysing bleaching solution consisting of a pump and pipes
by which the solution is caused to circulate through a cell in which are suspended a
number of platinum or equivalent plates electrically connected to one terminal of a
dynamo electric machine or other eloctrical generator and in which between the
platinum plates are caused to revolve zine dises that are connected to the other
terminal and are cleansed by stationary inclined scrapers, substantially as herein
described.
2. In apparatus for electrolysing bleaching solution, a cell partly divided by a
longitudinal vertical partition into two compartments in each of which is journalled
a horizontal shaft carrying a number of zinc discs, between which are suspended
platinum or equivalent plates, all these plates being connected to one terminal of an
electric generator whilst all the zinc discs are connected to the other terminal and
have inclined scrapers bearing against their faces and bosses, substantially as and for
the purpose set forth.
3. In apparatus for electrolysing bleaching solution the combination, in a trough,
through which the solution flows, of semi-cylinders of platinum or its equivalent
connected to one terminal of an electric generator and zinc cylinders connected to
the other terminal revolving above these, with scrapers bearing against them,
substantially as described.
4. In apparatus for electrolysing bleaching liquor, the combination of a set of
horizontal cylinders of platinum, or its equivalent, fixed insulated in a trough through
which the liquor flows, with zinc plungers moving to and fro within the said cylinders
and through guides armed with scrapers, substantially as described.
5. In apparatus for electrolysing bleaching liquor the combination of an external
platinum lined or equivalent cylinder connected to one terminal of an electric generator,
an internal smaller zinc cylinder insulated from the external cylinder and connected to
the other terminal, and a set of scrapers revolving in the annular space between the
cylinders, substantially as described.
Dil: ot. 1
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