CA2091943A1 - Electrochemical membrane cell - Google Patents
Electrochemical membrane cellInfo
- Publication number
- CA2091943A1 CA2091943A1 CA002091943A CA2091943A CA2091943A1 CA 2091943 A1 CA2091943 A1 CA 2091943A1 CA 002091943 A CA002091943 A CA 002091943A CA 2091943 A CA2091943 A CA 2091943A CA 2091943 A1 CA2091943 A1 CA 2091943A1
- Authority
- CA
- Canada
- Prior art keywords
- current
- accordance
- membrane cell
- cell
- electrochemical membrane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
- C25B9/70—Assemblies comprising two or more cells
- C25B9/73—Assemblies comprising two or more cells of the filter-press type
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
Abstract
ABSTRACT
An electrochemical membrane cell is provided with flat electrodes at either side, whereby each of the electrodes on the side turned away from the membrane is in electrical connection with an electrically conducting current-feeding component serving as a spacer, whereby each of the current-feeding conductors is connected to a support made of metal plate which surrounds the cell. The cathode is brought into electrical contact with the cathodic current-feeding component by flat contact surfaces, which meet under pressure applied by means of a spring element and is locked to protect against dislocation, whereby the connection between electrode and current-feeding structure may be detached once more by releasing the spring element, in order that the active electrode surfaces of the cathode may be easily exchanged. The membrane cell is mounted in an installation along with a plurality of membrane cells arranged in series.
An electrochemical membrane cell is provided with flat electrodes at either side, whereby each of the electrodes on the side turned away from the membrane is in electrical connection with an electrically conducting current-feeding component serving as a spacer, whereby each of the current-feeding conductors is connected to a support made of metal plate which surrounds the cell. The cathode is brought into electrical contact with the cathodic current-feeding component by flat contact surfaces, which meet under pressure applied by means of a spring element and is locked to protect against dislocation, whereby the connection between electrode and current-feeding structure may be detached once more by releasing the spring element, in order that the active electrode surfaces of the cathode may be easily exchanged. The membrane cell is mounted in an installation along with a plurality of membrane cells arranged in series.
Description
Patent Application Heraeus Elektrochemie GmbH
"Electrochemical Membrane Cell"
The invention relates to an electrochemical membrane cell with electrodes arranged on either side of each membrane, whereby in order to achieve a uniform distribution of current, both the anodic and the cathodic electrode are respectively connected via an electrically conductive current-feeding component acting as a spacer, to a metal-plate support serving as current distributors, whereby at least one current-feeding component of the cell is detachably connected to its related electrode by flat parts. An electrolytic cell working in accordance with the membrane procedure has been described in EP-OS 55 930; it is also referred to as a membrane cell. The placing of the electrodes on each side of the membrane is explained in more detail e.g. in DE-OS 36 25 506 which describes a foil-like membrane with electrodes placed to fit closely on each side.
In addition, an electrode component for membranes and/or diaphragm cells is known from DE-PS 35 19 272 and which involves a metal plate support acting as current distributor, on which a plurality of plated electrode elements forms a multi-layered structure in such a way as - : : . ~. .,. ........................ ., , ., .
~ ~, . . . , ,; : ,.
:. :: : : .................. . : .,. ,: . . : . :: .
. ' :' ' :. . :: . : . : ' .. :: :: .
to present an even surface, which is pressed directly on to the membrane.
This type of membrane cell requires renewal of the catalytically active layers of the electrodes at regular intervals of time; in practice, this means that the cathode layers in the membrane cells need to be renewed at very much shorter intervals than those of the anodes. This requires dismounting the entire set of membrane cell elements in order to remove the electrodes, so that their layers can be renewed, and then reinstalled along with any welding work which may be necessary.
An electrode component for membrane electrolytic cells with an even electrode structure and connected to a metal plate support serving as a current distributor via a metallic spacer is already known from DE-OS 37 26 674. These spacers take the form of a clamp-mounting consisting of a springy element and a rigid element, whereby each springy element is firmly fastened to the support, while the rigid element is connected to the electrode component part. This enables the active electrode components to be removed from their respective supports and sent away for reactivation immediately after dismounting whenever reactivation is required.
One problem here is the relatively uneconomical clamp-mounting, since the current passing between the clamp-,, . . . .,. . :
~ . . --` 209~9~3 mountings is almost entirely dependent on the spring tension and cannot subsequently be increased without complications. There is therefore additional resistance on account of the relatively small surfaces between the contact elements of the spring mounting which increases resistance to the current passing between them. It is furthermore difficult to achieve a uniform distribution of current with the spring-contact elements arranged in series.
The aim of the present invention is to create a detachable connection between the electrode and its respective cell-element whereby resistance to the passage of electrical current is practically negligible and in addition to this to provide a uniform supply of current over the electrode surface.
This aim has been achieved through the distinguishing character- istics of Claim 1.
In a useful adaptation of the invention, the current-feeding component is pressed against the flat surface of its related electrode by means of a spring component which acts on the outer part of the metal plate, pushing the two surfaces mechanically together to form an electrical contact surface.
The simple way in which the cathode is constructed is a distinct advantage, as it leads to lower manufacturing costs; a further advantage is the fact that it is possible .
.
.
20919~3 to mount and dismount the electrodes on site (i.e. by the user), as the costly transport expenses involved in sending away the complete cells in order to have the cathodes reactivated are thereby eliminated. .
Furthermore, work can be resumed immediately if a stock of replacement cathodes is kept on hand.
In a preferred form of the invention, the support surfaces are centred between the electrode component of the cathode and the cell element by form-locking elements which fit together in such a way that the optimum position is reached every time.
These locking elements consist of a recess and a projection which fits into the recess, and this arrangement also works together with the very important surface contacts to help ensure good electrical contact.
An advantage here is that the reactivated elements can very easily be replaced or removed by the system user without the need for special technical personnel; the conversion of older type cell elements with welded cathodes to cell elements in accordance with the invention is also very simple to carry out.
Additional advantageous adaptations of the invention are given in the sub-claims.
The object of the invention is clarified below by means of Figs. la, 1 b, lc, ld, le, lf, and 2a, 2b and 2c.
.. . .
~ . .
' ~ :~" ' ' `
"Electrochemical Membrane Cell"
The invention relates to an electrochemical membrane cell with electrodes arranged on either side of each membrane, whereby in order to achieve a uniform distribution of current, both the anodic and the cathodic electrode are respectively connected via an electrically conductive current-feeding component acting as a spacer, to a metal-plate support serving as current distributors, whereby at least one current-feeding component of the cell is detachably connected to its related electrode by flat parts. An electrolytic cell working in accordance with the membrane procedure has been described in EP-OS 55 930; it is also referred to as a membrane cell. The placing of the electrodes on each side of the membrane is explained in more detail e.g. in DE-OS 36 25 506 which describes a foil-like membrane with electrodes placed to fit closely on each side.
In addition, an electrode component for membranes and/or diaphragm cells is known from DE-PS 35 19 272 and which involves a metal plate support acting as current distributor, on which a plurality of plated electrode elements forms a multi-layered structure in such a way as - : : . ~. .,. ........................ ., , ., .
~ ~, . . . , ,; : ,.
:. :: : : .................. . : .,. ,: . . : . :: .
. ' :' ' :. . :: . : . : ' .. :: :: .
to present an even surface, which is pressed directly on to the membrane.
This type of membrane cell requires renewal of the catalytically active layers of the electrodes at regular intervals of time; in practice, this means that the cathode layers in the membrane cells need to be renewed at very much shorter intervals than those of the anodes. This requires dismounting the entire set of membrane cell elements in order to remove the electrodes, so that their layers can be renewed, and then reinstalled along with any welding work which may be necessary.
An electrode component for membrane electrolytic cells with an even electrode structure and connected to a metal plate support serving as a current distributor via a metallic spacer is already known from DE-OS 37 26 674. These spacers take the form of a clamp-mounting consisting of a springy element and a rigid element, whereby each springy element is firmly fastened to the support, while the rigid element is connected to the electrode component part. This enables the active electrode components to be removed from their respective supports and sent away for reactivation immediately after dismounting whenever reactivation is required.
One problem here is the relatively uneconomical clamp-mounting, since the current passing between the clamp-,, . . . .,. . :
~ . . --` 209~9~3 mountings is almost entirely dependent on the spring tension and cannot subsequently be increased without complications. There is therefore additional resistance on account of the relatively small surfaces between the contact elements of the spring mounting which increases resistance to the current passing between them. It is furthermore difficult to achieve a uniform distribution of current with the spring-contact elements arranged in series.
The aim of the present invention is to create a detachable connection between the electrode and its respective cell-element whereby resistance to the passage of electrical current is practically negligible and in addition to this to provide a uniform supply of current over the electrode surface.
This aim has been achieved through the distinguishing character- istics of Claim 1.
In a useful adaptation of the invention, the current-feeding component is pressed against the flat surface of its related electrode by means of a spring component which acts on the outer part of the metal plate, pushing the two surfaces mechanically together to form an electrical contact surface.
The simple way in which the cathode is constructed is a distinct advantage, as it leads to lower manufacturing costs; a further advantage is the fact that it is possible .
.
.
20919~3 to mount and dismount the electrodes on site (i.e. by the user), as the costly transport expenses involved in sending away the complete cells in order to have the cathodes reactivated are thereby eliminated. .
Furthermore, work can be resumed immediately if a stock of replacement cathodes is kept on hand.
In a preferred form of the invention, the support surfaces are centred between the electrode component of the cathode and the cell element by form-locking elements which fit together in such a way that the optimum position is reached every time.
These locking elements consist of a recess and a projection which fits into the recess, and this arrangement also works together with the very important surface contacts to help ensure good electrical contact.
An advantage here is that the reactivated elements can very easily be replaced or removed by the system user without the need for special technical personnel; the conversion of older type cell elements with welded cathodes to cell elements in accordance with the invention is also very simple to carry out.
Additional advantageous adaptations of the invention are given in the sub-claims.
The object of the invention is clarified below by means of Figs. la, 1 b, lc, ld, le, lf, and 2a, 2b and 2c.
.. . .
~ . .
' ~ :~" ' ' `
2 0 9 1 9 ~ 3 Fig. la shows a cell element of a membrane cell unit with anode and cathode and the accompanying electrode components;
Fig. lb, Section A, shows a sectional enlargement of the shaded area within the circle in Fig. la;
Fig. lc shows a sectional perspective view of the current-feeding component attached to the support along with part of the cathode;
Fig. ld shows the same arrangement as in Fig. la, with a plurality of cells;
Fig. le, Section B, shows the contact area where the passage of current occurs in two neighbouring cells;
Fig. lf, Section C shows the area between membrane, cathode and cathodic current-feeding component expanded in space.
Fig. 2a shows in lateral cross-section how several cell elements are connected together;
Fig. 2b represents a sectional enlargement of the shaded area within the circle shown in Fig. 2a;
Fig. 2c shows a perspective view of the membrane cell contained in the assembly along with the diagrammatic representation of two cell elements;
In accordance with Fig. 1, the cell element (1) consists of two half-shells (2 and 3), each enclosing an anode (4) with an anodic current-feeding component (5) and a cathode (6) with a cathodic current-feeding component. A membrane (8) is stretched between anode (4) and cathode (6) dividing the .
f . .: , , 20919~3 ...
interior of cell-element (1) into an anolyte chamber (9) and a catholyte c~lamber (10). In the anolyte chamber (~) ancl catholyte chamber (10) are located respectively the anodic current-feeding component (5) and the cathodic current-feeding component (7) providing the current connection between the electrodes and the inner wall of half-shells (2,3) as well as mechanical support for the electrodes against the membrane (8). The two half-shells (2) and (3) are protected at their end areas (50) by locking elements (11) as well as by seals (12) all around so as to prevent the loss of gas and liquid. The anodic and cathodic current-feeding components (5 and 7) are made in the form of curved bands, each of which has an electrically conductive and mechanically fixed connection (16,19) to the inner side of its respective half-shell (2 and 3).
On the outer side of half-shall (2) belonging to the anodic component, contact strips (13) are provided for the purpose of making contact with the neighbouring cathode, not shown here, consisting of a diffusion-welded or explosion-welded titanium-nickel band, the titanium surface (14) of which is welded onto the half-shell (2) consisting of titanium, while its nickel surface (15) makes the external contact with the neiyhbouring cathodic element.
The symbolically represented welding points (26) between contact strips (13) and half-shell (2) are produced by resistance welding. On the side turned away from half-shell .
. . .. .
(2), anodic component (5) consisting of curved bands is sim:ilarly connected to the activated surface of anode (4) by resistance-welded points (17). Between anode (4) and membrane (8), an electrically insulated anolyte-resistant spacer (18) is provided to hold anode (4) against the membrane. On the cathode side, half-shell (3) is likewise connected to the curved band serving as the cathodic current-feeding component (7) by resistance-welded points (19) in such a way as to be electrically conductive and mechanically firm. The half-shell (3), as well as the curved band actiny as cathodic current-feeding component (7) and cathode (6), consist chiefly of nickel.
A cation exchanger membrane is installed as membrane (8).
As may be seen from Fig. lb Section A referring to Fig. la, flexible catholyte-resistant electrical insulating material has been inserted between cathode (6) and membrane (8) congruent with the anodic side of the spacer (23). So that cathode (6) is held on the curved bands acting as the cathodic current-feeding component (7), superimposed openings (21, 22) are provided in both the cathode (6) and the curved band in the areas where they meet, through each of which a holding pin (38) shaft is brought so that the broad head of the pin (39) lies on the outer side of the cathode; the pins (38) are mostly made of nickel, although it is possible to use pins made of other material, e.g.
synthetic material. Electrical contact essentially takes , 2 ~ ~ 1 9 ~ 3 place by the contact surface area of the cathodic current-feeding component (7) pressing ayainst that of the cathode (6).
A useful variation is to have the heads (39~ of the fixing-pins (38) inserted in such a way as to also serve as a stop for the spacer placed between cathode and membrane.
The existing arrangement, consisting of membrane (8), spacers (18, 23), anode, anodic current-feeding component, cathode, cathodic current-feeding component and half-shells (2 and 3) is pressed together vertically with respect to the surface of the membrane by a force exerting pressure on it from outside and then held in the locked position, so being protected against lateral displacement.
In order to dismount a cell element (1), the pressure exerted by the force is relieved and the locking elements (11) which hold the sealing elements (12) together are released; next, the half-shell acting as support (3) is removed from the half-shell acting as support (2), so that cathode (6) can be removed from the cathodic current-feeding component (7). After cathode (6) has been reactivated, it is then attached to the curved bands acting as the cathodic current-feeding component, whereby the holding-pin (38) moves into the recesses (21,22) of the cathode (6) and the current-feeding component (7), thus preventing lateral displacement. After assembly of cell elements (1) the necessary contact pressure is provided , . , ~: . : ~ , : , , ' 20919~3 once more by the action of the external force as diagrammatically illustrated below in Fig. ld.
Fig. lc shows the support (3) with the attached cathodic current-feeding component in section. The current-feeding components (7) take the form of a curved band, whereby the surfaces facing the cathode (6) each have an opening (22) to receive the holding-pin (38) which is inserted through opening (21) of the cathode. In place of individual holding pins, it is also possible here to install bands (40) or, if desired, spacers with a pin shaped structure, so that their respective pin-shafts (41) would pass through openings (21,22) to act as holding-pins. The spacers, not shown here, would go into opening (21) and in order to provide better stopping they would likewise be provided with an recess to receive the heads (39) of the pins (38).
Figure 1 d illustrates the cell component already described in Fig. la, with a plurality of cells, and shows the individual cells represented diagrammatically in several stages of assembly while the force exerting pressure on the two outer cells is shown symbolically.
Cell (45) illustrates that state of assembly where the holding-pins (38) are not yet inserted into the openings of cathode (6) and cathodic current-feeding component (7), while the heads (39) of the holding-pins are all aligned to the membrane. On the anode side, anode (4) and anodic current-feeding component (5) are firmly joined by point , : . . , ., - . ................ : .
~, ~ , , ,- -2~9~943 welding, both electrically and mechanically, by point welding where -their surfaces meet; cell (46) is shown immediately before assembly with the holding-pins (38) already inserted in the superimposed openings (21,22) of cathode (6) and current-feeding component (7) while the spacers are not yet stopped by the holding-pin heads (39).
Cells 47, 48, 49 are examples of cells which have already been assembled, with the sealing and locking elements which belong at the ends omitted here in the interests of clarity.
Fig. le shows in detail an enlargement of Section B, Fig. ld, showing clearly the current-passing area between two neighbouring cells (47,48) such that when pressure is applied, contact takes place between contact strip (13) and the outside of the cathode half-shell (3).
Fig. lf shows an enlargement of Section C, Fig. ld, whereby in order to give a better overall view, membrane 8 is shown expanded away from cathode (6) with its current-feeding component (7) partly indicated. Holding-pin (38) passes through openings (21,22) of cathode (6) and current-feeding component (7).
The longitudinal section in Fig. 2A shows several cell elements connected in series, together with the two face-plates through which the spring pressure is exerted and contact takes place; for the sake of clarity, only three ''- ` ~' :' .`' ' ' -, " '' ~, . . . .
- .:: .
: . : ,. ~
, . ~ ~ , ' ' ' cells are shown here in the released state, i.e. no pressure is being exerted in Fig. 2a.
Each of the three cell elements (1) exhibits an anodic and cathodic current-feeding component (5) (7), consisting of several curved bands arranged in parallel, shown here in a lateral view. This particular example shows three curved bands, however it is also possible to increase the number of such bands, depending on the size of the electrode surface.
In Fig. 2b (Section D), the contact strip (13) is visible in cross-section on the anode side, and consists of a titanium- nickel band, whereby titanium and nickel are welded together by diffusion or explosion welding and the contact strip (13) on the titanium side is attached to the outside of the anodic half-shell by resistance welding.
Because of the series connection, the nickel part (14) contacts the outside of the neighbouring cathodic half-shell (3) which consists chiefly of nickel.
The cathode and anode of the two outside cells shown in Fig. 2a are connected respectively to the cathodic face-plate ~24) and the anodic face-plate (25), while both face-plates have a rigid component in order to transmit the spring tension, and in each case have contact elements chiefly of nickel (34,35) on the side facing the cell elements. The two face-plates (24, 25) are pressed together along axis (33) by the partly indicated screwed , .... - - " :. ::
2Q~1943 bolt (30) and by nuts (31,32) in such a way that the half-shells on the anode side are each electrically connected, with very low electrical resistance, to the respective half-shells on the cathode side of the neighbouring cell element by the pressure exerted to bring the contact strips (13) and the half-shell (3) together, while the contact made between the two outer face-plates (24,25) and the neighbouring half-shells (2,3) likewise also offers very little resistance to the passage of the current. In order to avoid a short-circuit, the screwed bolts (30) and the nuts (31,32) are insulated from the face-plates by electrically insulated bushings (28,29). In the case of rectangular face-plates, the screwed bolts are so arranged that there is one in each corner; for the sake of clarity, only one bolt (30) is shown here in a lower corner. The current connections of the cathodic face plate (24) and the anodic face-plate (25) are designated as (36) and (37) respectively.
Figure 2 c shows a membrane cell in position, with cell elements placed between the two face-plates (24,25) held at their four corners with the help of screwed bolts (30).
The cell elements are connected in such a way that the cathode of each cell element is connected with the anode of the neighbouring element. After cell elements (1) are in place, the nuts (31,32) of both face-plates are tightened until there is only a very low resistance to the passage of ...
" , ..
., . .- , 20919~3 current between neighbouring cells. The external supply of current is supplied via current connections (36,37) of the cathodic face-plate (24~ and anodic face-plate (25).
It is however also possible to have the cells hanging vertically and parallel to each other, arranged within a frame-type construction with the individual cells having support elements running from their edges as an extension of the membrane surface, and resting on a horizontally-running support surface of the frame construction.
The current density is in the range of 1 kA to 5 kA per m2.
The cells are particularly suited to chlorine-alkali electrolysis, but the arrangements for gas and liquid removal are not shown here in order to give a better overall view.
- , ;::. :,: :. ., , . :
:: : :. .. : : ::. . .
Fig. lb, Section A, shows a sectional enlargement of the shaded area within the circle in Fig. la;
Fig. lc shows a sectional perspective view of the current-feeding component attached to the support along with part of the cathode;
Fig. ld shows the same arrangement as in Fig. la, with a plurality of cells;
Fig. le, Section B, shows the contact area where the passage of current occurs in two neighbouring cells;
Fig. lf, Section C shows the area between membrane, cathode and cathodic current-feeding component expanded in space.
Fig. 2a shows in lateral cross-section how several cell elements are connected together;
Fig. 2b represents a sectional enlargement of the shaded area within the circle shown in Fig. 2a;
Fig. 2c shows a perspective view of the membrane cell contained in the assembly along with the diagrammatic representation of two cell elements;
In accordance with Fig. 1, the cell element (1) consists of two half-shells (2 and 3), each enclosing an anode (4) with an anodic current-feeding component (5) and a cathode (6) with a cathodic current-feeding component. A membrane (8) is stretched between anode (4) and cathode (6) dividing the .
f . .: , , 20919~3 ...
interior of cell-element (1) into an anolyte chamber (9) and a catholyte c~lamber (10). In the anolyte chamber (~) ancl catholyte chamber (10) are located respectively the anodic current-feeding component (5) and the cathodic current-feeding component (7) providing the current connection between the electrodes and the inner wall of half-shells (2,3) as well as mechanical support for the electrodes against the membrane (8). The two half-shells (2) and (3) are protected at their end areas (50) by locking elements (11) as well as by seals (12) all around so as to prevent the loss of gas and liquid. The anodic and cathodic current-feeding components (5 and 7) are made in the form of curved bands, each of which has an electrically conductive and mechanically fixed connection (16,19) to the inner side of its respective half-shell (2 and 3).
On the outer side of half-shall (2) belonging to the anodic component, contact strips (13) are provided for the purpose of making contact with the neighbouring cathode, not shown here, consisting of a diffusion-welded or explosion-welded titanium-nickel band, the titanium surface (14) of which is welded onto the half-shell (2) consisting of titanium, while its nickel surface (15) makes the external contact with the neiyhbouring cathodic element.
The symbolically represented welding points (26) between contact strips (13) and half-shell (2) are produced by resistance welding. On the side turned away from half-shell .
. . .. .
(2), anodic component (5) consisting of curved bands is sim:ilarly connected to the activated surface of anode (4) by resistance-welded points (17). Between anode (4) and membrane (8), an electrically insulated anolyte-resistant spacer (18) is provided to hold anode (4) against the membrane. On the cathode side, half-shell (3) is likewise connected to the curved band serving as the cathodic current-feeding component (7) by resistance-welded points (19) in such a way as to be electrically conductive and mechanically firm. The half-shell (3), as well as the curved band actiny as cathodic current-feeding component (7) and cathode (6), consist chiefly of nickel.
A cation exchanger membrane is installed as membrane (8).
As may be seen from Fig. lb Section A referring to Fig. la, flexible catholyte-resistant electrical insulating material has been inserted between cathode (6) and membrane (8) congruent with the anodic side of the spacer (23). So that cathode (6) is held on the curved bands acting as the cathodic current-feeding component (7), superimposed openings (21, 22) are provided in both the cathode (6) and the curved band in the areas where they meet, through each of which a holding pin (38) shaft is brought so that the broad head of the pin (39) lies on the outer side of the cathode; the pins (38) are mostly made of nickel, although it is possible to use pins made of other material, e.g.
synthetic material. Electrical contact essentially takes , 2 ~ ~ 1 9 ~ 3 place by the contact surface area of the cathodic current-feeding component (7) pressing ayainst that of the cathode (6).
A useful variation is to have the heads (39~ of the fixing-pins (38) inserted in such a way as to also serve as a stop for the spacer placed between cathode and membrane.
The existing arrangement, consisting of membrane (8), spacers (18, 23), anode, anodic current-feeding component, cathode, cathodic current-feeding component and half-shells (2 and 3) is pressed together vertically with respect to the surface of the membrane by a force exerting pressure on it from outside and then held in the locked position, so being protected against lateral displacement.
In order to dismount a cell element (1), the pressure exerted by the force is relieved and the locking elements (11) which hold the sealing elements (12) together are released; next, the half-shell acting as support (3) is removed from the half-shell acting as support (2), so that cathode (6) can be removed from the cathodic current-feeding component (7). After cathode (6) has been reactivated, it is then attached to the curved bands acting as the cathodic current-feeding component, whereby the holding-pin (38) moves into the recesses (21,22) of the cathode (6) and the current-feeding component (7), thus preventing lateral displacement. After assembly of cell elements (1) the necessary contact pressure is provided , . , ~: . : ~ , : , , ' 20919~3 once more by the action of the external force as diagrammatically illustrated below in Fig. ld.
Fig. lc shows the support (3) with the attached cathodic current-feeding component in section. The current-feeding components (7) take the form of a curved band, whereby the surfaces facing the cathode (6) each have an opening (22) to receive the holding-pin (38) which is inserted through opening (21) of the cathode. In place of individual holding pins, it is also possible here to install bands (40) or, if desired, spacers with a pin shaped structure, so that their respective pin-shafts (41) would pass through openings (21,22) to act as holding-pins. The spacers, not shown here, would go into opening (21) and in order to provide better stopping they would likewise be provided with an recess to receive the heads (39) of the pins (38).
Figure 1 d illustrates the cell component already described in Fig. la, with a plurality of cells, and shows the individual cells represented diagrammatically in several stages of assembly while the force exerting pressure on the two outer cells is shown symbolically.
Cell (45) illustrates that state of assembly where the holding-pins (38) are not yet inserted into the openings of cathode (6) and cathodic current-feeding component (7), while the heads (39) of the holding-pins are all aligned to the membrane. On the anode side, anode (4) and anodic current-feeding component (5) are firmly joined by point , : . . , ., - . ................ : .
~, ~ , , ,- -2~9~943 welding, both electrically and mechanically, by point welding where -their surfaces meet; cell (46) is shown immediately before assembly with the holding-pins (38) already inserted in the superimposed openings (21,22) of cathode (6) and current-feeding component (7) while the spacers are not yet stopped by the holding-pin heads (39).
Cells 47, 48, 49 are examples of cells which have already been assembled, with the sealing and locking elements which belong at the ends omitted here in the interests of clarity.
Fig. le shows in detail an enlargement of Section B, Fig. ld, showing clearly the current-passing area between two neighbouring cells (47,48) such that when pressure is applied, contact takes place between contact strip (13) and the outside of the cathode half-shell (3).
Fig. lf shows an enlargement of Section C, Fig. ld, whereby in order to give a better overall view, membrane 8 is shown expanded away from cathode (6) with its current-feeding component (7) partly indicated. Holding-pin (38) passes through openings (21,22) of cathode (6) and current-feeding component (7).
The longitudinal section in Fig. 2A shows several cell elements connected in series, together with the two face-plates through which the spring pressure is exerted and contact takes place; for the sake of clarity, only three ''- ` ~' :' .`' ' ' -, " '' ~, . . . .
- .:: .
: . : ,. ~
, . ~ ~ , ' ' ' cells are shown here in the released state, i.e. no pressure is being exerted in Fig. 2a.
Each of the three cell elements (1) exhibits an anodic and cathodic current-feeding component (5) (7), consisting of several curved bands arranged in parallel, shown here in a lateral view. This particular example shows three curved bands, however it is also possible to increase the number of such bands, depending on the size of the electrode surface.
In Fig. 2b (Section D), the contact strip (13) is visible in cross-section on the anode side, and consists of a titanium- nickel band, whereby titanium and nickel are welded together by diffusion or explosion welding and the contact strip (13) on the titanium side is attached to the outside of the anodic half-shell by resistance welding.
Because of the series connection, the nickel part (14) contacts the outside of the neighbouring cathodic half-shell (3) which consists chiefly of nickel.
The cathode and anode of the two outside cells shown in Fig. 2a are connected respectively to the cathodic face-plate ~24) and the anodic face-plate (25), while both face-plates have a rigid component in order to transmit the spring tension, and in each case have contact elements chiefly of nickel (34,35) on the side facing the cell elements. The two face-plates (24, 25) are pressed together along axis (33) by the partly indicated screwed , .... - - " :. ::
2Q~1943 bolt (30) and by nuts (31,32) in such a way that the half-shells on the anode side are each electrically connected, with very low electrical resistance, to the respective half-shells on the cathode side of the neighbouring cell element by the pressure exerted to bring the contact strips (13) and the half-shell (3) together, while the contact made between the two outer face-plates (24,25) and the neighbouring half-shells (2,3) likewise also offers very little resistance to the passage of the current. In order to avoid a short-circuit, the screwed bolts (30) and the nuts (31,32) are insulated from the face-plates by electrically insulated bushings (28,29). In the case of rectangular face-plates, the screwed bolts are so arranged that there is one in each corner; for the sake of clarity, only one bolt (30) is shown here in a lower corner. The current connections of the cathodic face plate (24) and the anodic face-plate (25) are designated as (36) and (37) respectively.
Figure 2 c shows a membrane cell in position, with cell elements placed between the two face-plates (24,25) held at their four corners with the help of screwed bolts (30).
The cell elements are connected in such a way that the cathode of each cell element is connected with the anode of the neighbouring element. After cell elements (1) are in place, the nuts (31,32) of both face-plates are tightened until there is only a very low resistance to the passage of ...
" , ..
., . .- , 20919~3 current between neighbouring cells. The external supply of current is supplied via current connections (36,37) of the cathodic face-plate (24~ and anodic face-plate (25).
It is however also possible to have the cells hanging vertically and parallel to each other, arranged within a frame-type construction with the individual cells having support elements running from their edges as an extension of the membrane surface, and resting on a horizontally-running support surface of the frame construction.
The current density is in the range of 1 kA to 5 kA per m2.
The cells are particularly suited to chlorine-alkali electrolysis, but the arrangements for gas and liquid removal are not shown here in order to give a better overall view.
- , ;::. :,: :. ., , . :
:: : :. .. : : ::. . .
Claims (15)
1. Electrochemical membrane cell with electrodes arranged on both sides of each membrane, whereby for the purpose of achieving a uniform distribution of current, both the anodic electrode and the cathodic electrode are respectively connected via an electrically conductive current-feeding component acting as a spacer to a support made of metal plate serving as a current distributor, whereby at least one current-feeding component of the cell is detachably connected to its related electrode through flat parts, characterized in that at least one of the two electrodes (4,6) makes electrical contact with its related current-feeding component through flat contact surfaces which meet under pressure to allow the transmission of electric current.
2. Electrochemical membrane cell in accordance with Claim 1, characterized in that the current-feeding component (5,7) acts against the flat surface of the its related electrode (4,6) by means of a spring component acting on the outer part of the metal plates to push the two surfaces mechanically together thus providing an electrical surface contact.
3. Electrochemical membrane cell in accordance with Claim 1 or 2, characterized in that the cathodic current-feeding component (7) is pressed against the flat parts of its related cathode. (6).
4. Electrochemical membrane cell in accordance with Claim 3, characterized in that the flat parts of the cathode (6) and the current-feeding component (7) are brought into alignment by form-locking elements (21, 22, 38, 41) which fit together.
5. Electrochemical membrane cell in accordance with Claim 4, characterized in that the locking elements each onsist of a recess (21,22) and a pin (38) which fits into the recess.
6. Electrochemical membrane cell in accordance with one of Claims 1 to 5, characterized in that at least the cathodic current-feeding component (7) and the cathodic support (3) are constructed of metal plate which is springy in the direction of the normal surface of the membrane.
7. Electrochemical membrane cell in accordance with one of Claims 1 to 6 characterized in that at least the cathodic current-feeding component (7) and the cathode (6) are composed chiefly of nickel.
8. Electrochemical membrane cell in accordance with one of Claims 1 to 7, characterized in that the metal plates which serve as supports (2) are each provided on their external surfaces with welded-on contact elements (13), of which at least the surface consists chiefly of nickel.
9. Electrochemical membrane cell in accordance with one of Claims 1 to 7 characterized in that the metal plates serving as supports (2, 3) of neighbouring cells are each provided with contact clamps consisting of material which is a good conductor of electricity, whereby the half-shell which serves to support (2) the anode has at least one surface serving as contact element, and the half-shell which acts as the cathodic support (3) has at least one contact element welded to it.
10. Electrochemical membrane cell in accordance with Claim 8, characterized in that the contact element of the anodic support (2) is metallically sprayed.
11. Electrochemical membrane cell in accordance with one of Claims 1 to 10, characterized in that the spring component has two face-plates (24,25) provided with contact elements (34,35) whereby the pressure required for making contact can be generated through screwed elements which act perpendicular to the surface of the membrane.
12. Electrochemical membrane cell in accordance with Claim 11, characterized in that the screwed elements are uniformly distributed over the surface of the contact area.
13. Electrochemical membrane cell in accordance with Claim 11 or 12 characterized in that the metal plates serving as supports (2,3) are located between at least two screw bolts.
14. Electrochemical membrane cell in accordance with Claim 11 characterized in that the face-plates (24,25) consist of material which is highly conductive of electricity and that the screw bolts (30) and screwed elements (31,32) are insulated from face-plates (28,29) by means of electrically insulated bushings.
15. Electrochemical membrane cell in accordance with one of Claims 1 to 14, characterized in that at least two cell elements (1) are arranged in series between two face-plates (24,25).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4212678A DE4212678A1 (en) | 1992-04-16 | 1992-04-16 | Electrochemical membrane cell |
| DEP4212678.9 | 1992-04-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2091943A1 true CA2091943A1 (en) | 1993-10-17 |
Family
ID=6456904
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002091943A Abandoned CA2091943A1 (en) | 1992-04-16 | 1993-03-18 | Electrochemical membrane cell |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0565836A1 (en) |
| JP (1) | JPH0641777A (en) |
| CA (1) | CA2091943A1 (en) |
| DE (1) | DE4212678A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19859882A1 (en) * | 1998-12-23 | 1999-12-09 | W Strewe | Ion exchange membrane cell used in the production of chlorine gas, hydrogen gas and alkali lye by electrolyzing alkali chloride solutions |
| JP5493787B2 (en) * | 2009-12-04 | 2014-05-14 | 東ソー株式会社 | Ion exchange membrane electrolytic cell |
| EP3464683B1 (en) * | 2016-05-26 | 2021-07-07 | Calera Corporation | Anode assembly, contact strips, electrochemical cell, and methods to use and manufacture thereof |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES450933A1 (en) * | 1975-08-29 | 1977-09-01 | Hoechst Ag | Electrolytic apparatus |
| DE2909640A1 (en) * | 1979-03-12 | 1980-09-25 | Hoechst Ag | ELECTROLYSIS |
| DE2914869A1 (en) * | 1979-04-12 | 1980-10-30 | Hoechst Ag | ELECTROLYSIS |
| US4368109A (en) * | 1980-11-05 | 1983-01-11 | Olin Corporation | Electrolytic cell with inter-electrode spacer means |
| DE3501261A1 (en) * | 1985-01-16 | 1986-07-17 | Uhde Gmbh, 4600 Dortmund | ELECTROLYSIS |
| DE3519272C1 (en) * | 1985-05-30 | 1986-12-18 | Heraeus Elektroden GmbH, 6450 Hanau | Electrode structure for electrochemical cells |
| NL8601906A (en) * | 1985-07-29 | 1987-02-16 | Permelec Electrode Ltd | ELECTRODE FOR ELECTROLYSIS WHEN APPLYING A DIAPHRAGM. |
| DE3726674A1 (en) * | 1987-08-11 | 1989-02-23 | Heraeus Elektroden | ELECTRODE STRUCTURE FOR ELECTROCHEMICAL CELLS |
| DE4014778A1 (en) * | 1990-05-09 | 1991-11-14 | Metallgesellschaft Ag | ELECTROLYSIS |
-
1992
- 1992-04-16 DE DE4212678A patent/DE4212678A1/en not_active Withdrawn
-
1993
- 1993-02-26 EP EP93103012A patent/EP0565836A1/en not_active Withdrawn
- 1993-03-18 CA CA002091943A patent/CA2091943A1/en not_active Abandoned
- 1993-04-07 JP JP5080720A patent/JPH0641777A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP0565836A1 (en) | 1993-10-20 |
| DE4212678A1 (en) | 1993-10-21 |
| JPH0641777A (en) | 1994-02-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |