US2834728A - Method and apparatus for protecting the cathodes of electrolytic cells - Google Patents

Method and apparatus for protecting the cathodes of electrolytic cells Download PDF

Info

Publication number
US2834728A
US2834728A US413332A US41333254A US2834728A US 2834728 A US2834728 A US 2834728A US 413332 A US413332 A US 413332A US 41333254 A US41333254 A US 41333254A US 2834728 A US2834728 A US 2834728A
Authority
US
United States
Prior art keywords
cell
cathode
anodes
contact
segments
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.)
Expired - Lifetime
Application number
US413332A
Other languages
English (en)
Inventor
Gallone Patrizio
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
De Nora SpA
Original Assignee
Oronzio de Nora Impianti Elettrochimici SpA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Oronzio de Nora Impianti Elettrochimici SpA filed Critical Oronzio de Nora Impianti Elettrochimici SpA
Application granted granted Critical
Publication of US2834728A publication Critical patent/US2834728A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • 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
    • C25B15/00—Operating or servicing cells
    • 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
    • C25B9/60—Constructional parts of cells
    • C25B9/65—Means for supplying current; Electrode connections; Electric inter-cell connections

Definitions

  • This invention relates to a method and apparatus for protecting the cathode of an electrolytic cell from attack by the electrolyte and electrolysis product during periods when the cell is cut out of the main electrolysis circuit.
  • the method and apparatus of. my invention may be used, in general, in all electrolysis apparatus in which the cathode has a reactivity with respect to the electrolyte and the electrolysis products when the flow of the electrolysis current between the anode and the cathode of the cell is stopped.
  • auxiliary anodes are used to maintain a small polarizing current over the cathode by means of an auxiliary source of electromotive force, during the period in which the main anodes are short-circuited with the cathode.
  • One of the objects of my invention is to provide a method of protecting the cathodes of electrolytic cells during shut-down of the cell, by maintaining a small polarizing current between the main anodes and the cathode of the cell.
  • Another object of my invention is to provide a method of protecting the cathodes of electrolytic cells, whereby it is possible to cut a cell out of the electrolysis circuit without short-circuiting' the cell.
  • Another object of my invention is to provide means by which an electrolytic cell may be cut out of the main circuit and the main anodes used as protective anodes during the period of inactivity of the cell.
  • Another object of my invention is to provide improved switch means for cutting an electrolytic cell out of the electrolysis circuit and simultaneously impressing a protective circuit between the main anodes and the cathode of the cell.
  • Another object of my invention is to provide a method and apparatus which permits a cell to be cut out of the electrolysis circuit without short-circuiting the cell and.to provide automatically for the maintenance of a protective current between the anodes and the cathode ofthe cell during periods in which this cell is out of operation.
  • Fig. 1 is a diagrammatic illustration of a pair of electrolytic mercury cells to which my invention has been applied;
  • Fig. 2 is a part sectional end view of a switching means suitable for use in carrying out the principles of my invention
  • Fig. 3 is a side view of the switch illustrated in Fig. 2, taken from the right of Fig. 2;
  • Fig. 4 is a sectional view of the switch illustrated in Fig. 3, taken along the line 4--4 of Fig. 3;
  • Fig. 5 is a part sectional view taken along the line 55 of Fig. 4.
  • Fig. 6 is a detailed view showing the switch in one of its positions.
  • FIG. 1 two amalgam cells, 1 and 2 are shown in which the mercury cathode flows along the sloped bottom of the cells and the electrolysis current, during operation of the cell, flows between the anodes A and the cathode B. Brine is circulated between the anodes and the cathode and for the production of chlorine and caustic soda is decomposed into chlorine and sodium, which later is amalgamated with the mercury flowing along the bottom of cells 1 and 2.
  • the cell 1 is represented as in the process of being cut out of the main electrolysis circuit, While the cell 2 is shown in the main electrolysis line.
  • the cell 1 or any other cell in the electrolysis circuit may be cut out of the circuit by disconnecting the negative bus bar 3 coming from a cell in the row from the positive 'bus bar 4 of the cell 1 to be cut out of 'operation, while the following cell 2 remains connected through the negative bus bar 7 and the positive bus bar 4, so that the electrolysis current is carried through the bus bar 3, switch member 5, bus bar 7 and bus bar 4 to the cell 2, while the cell 1 is cut out of the electrolysis circuit.
  • the switch members 5, which may be of a detailed construction such as that illustrated in Figs.
  • switch handle 6 and switch bar 8 are operated by means of a switch handle 6 and switch bar 8 to movethe switch element to the position to disconnect cell 1 from the electrolysis circuit or with reference to cell 2, to either. include the cell in the electrolysis current, or to disconnect the cell from the electrolysis current.
  • switch member 5 is illustrated in an inter.- mediate position with reference to cell 1 in which the switch member is passing from a position Where itconnects bus bar 3 with bar 4 to a position where this connection is broken and connection established between bar 3 and bar 7.
  • the switch element 5 is constructed so that when a cell is being cut into or out of the circuit, the electrical connection between the bus bar 3 and the bar 7 will be established before the connection between the bar 3 and the bar 4 is broken, and vice versa.
  • the switch bar 8 is provided with an auxiliary contact member 9 which is constructed to make contact with the contacts 9a and 9b as soon as the cell is cut out of the main circuit to connect the anodes A and cathode B with the positive and negative pole respectively of a source of polarizin-g voltage 10.
  • a ballast resistor 11 is preferably inserted in the polar- 1 izing circuit in order to protect the voltage source from damaging current surges, which might arise if the voltage source 10 were connected without ballast to a cell which had not yet acquired or had lost its polarizing conditions.
  • the polarizing voltage source 10 which is provided for each cell preferably consists of a battery of very small capacity and a trickle charge system 12fed by alternating current means so that the voltage source 10 is maintained at the desired potential.
  • any suitable source of polarizing voltage 10 may be used.
  • an auxiliary contact 13 may also be provided on the electrolysis power circuit breaker which will close automatically when the electrolysis circuit breaker opens. Through the closing of the contact 13 an exciting current will be sent to the relay 14, which is provided in each polarizing circuit, so that the relay 14 will close the polarizing circuit, upon any failure of the electrolysis power, even when the cell disconnect switch is closed and the auxiliary contact 9 is in open position, as illustrated in connection with cell 2.
  • the switch handle 6 is moved in a clockwise direction to move the contact switch member 5 from the position in which it makes contact between the bus bar 3 and the positive bar 4 to the position in which the member 5 is out of contact with the bar 4 but is in contact with the negative bar 7, leading to the next cell.
  • the contact between the bar 3 and the bar 4 is not broken until the contact between the bar 3 and the bar 7 has been made.
  • the switch bar 8 moves the contact member 9 into contact with contacts 9a and 9b to complete the polarizing circuit from the positive side of the source 10 to the anodes A and from the negative side of the source 10 to the cathode B, so that the polarizing voltage is immediately impressed on the cell which is cut out of the circuit.
  • the circuit between the source 10 and the anodes A and cathode B is completed by the closing of the contacts of the relay 14 which is operated automatically by the contact 13 on any failure or break in the electrolysis power line.
  • the anodic current density will also be nearly the same as the cathodic current density.
  • the voltage difference at the cell terminals amounts to about 1 volt, so that the anode potential is much lower than the chlorine discharge potential. It is therefore unnecessary to provide means for neutralizing any possible evolution of chlorine gas, as is required when using auxiliary anodes of small dimensions.
  • switch element 5 adapted to make contact between the two bus bars to be connected before the contact between the two bars to be disconnected is broken
  • switch illustrated in greater detail in Figs. 2 to 6 particularly well adapted for use according to our invention.
  • This switch consists of the contact members 5 mounted on switch bar 8 and adapted to make or break contact between bars 3, 4 and '7 corresponding to the bars illustrated diagrammatically in Fig. l.
  • Contact members 33, 44 and 77 are connected, respectively, to the bars 3, 4-and 7 and are supported by a U-shaped bracket 21, to which the contact members 33, 44 and 77 are connected, respectively, at 22, 23 and-24, suitable insulation being provided at these connections as indicated more particularly in Fig. 4, so that electrical contact between the contact bars 33, 44 and 77 will be made only through the switch members 5.
  • the brackets 21 are also provided with lower bearing members 34 and removable cap bearing members 35, so as to provide a journal through which the shaft 8 extends and in which bearings the shaft 8 may be rotated to control the position of the switch members 5.
  • the position of the switch members 5 is changed by the rotation of the shaft 8, which is connected through keys 26 to the separate elements of the switch members 5 in such a way as to allow some radial play for the switch contacts 5.
  • the shaft 8 is provided with two collars 27, which are rigidly fixed to the shaft, and which support two rods 28,
  • the switch members 5 are preferably made of a silver alloy or of any other metal particularly suitable for electrical contacts, and the switch members 5 are preferably divided into three sections, as indicated particularly in Figs. 3 and 5, so as to provide a plurality of contact points and insure good contact between the switch members and the contact bars 33, 44 or 77 at all times.
  • the contact bars 33, 44 and 77 which are usually made of copper, may have their ends silver-plated or may have a suitable contact alloy brand to the ends of the contact bars.
  • the switch members 5 When the control shaft 8 is turned to switch-in position, for a particular cell, the switch members 5 will be pressed against the bars 44 and 33, so that the electrolysis current will be led by the contact 44 and anode bar 4 to the anode of this cell and after passing through the cell, will be conducted through the cathode bar 7 connected across the base of the cell to the next adjacent cell.
  • the shaft 8 When it is desired to cut a cell out of the electrolysis circuit, the shaft 8 will be rotated so that the switch members 5 will be turned to connect contact 33 with contact 77 and to disconnect contact 44 from contact 33.
  • the switch members 5 will temporarily pass through the intermediate position as indicated in Figs. 1, 2 and 4, in which position the switch members 5 will contact all of the three contact bars 33, 44 and 77, so that there will be no interruption of the continuity of the circuit to the remaining cells in the circuit as the switch members 5 move from one position to another.
  • This intermediate position of the switch members 5 will correspond to a momentary short-circuiting condition for the cell being cut out of the circuit, but this shortcircuiting condition will last for only a short period of time as the contact member 9 will be brought into contact with the contacts 9a and 9b as soon as the switch member 5 has reached the position indicated in Fig. 6 in which it has broken contact with the contact bar 44 and remains in contact with the contact bars 33 and 77.
  • a polarizing current will be impressed between the main anodes A and the cathode B, so that the short-circuiting effect will be of only short duration.
  • Each cell is preferably provided with two or more switch elements 5 as described above; preferably, the cells will be provided with as many switches as there are anodes in the cell, and as many cathode bus bars as are necessary to feed the anodes in parallel to each cell.
  • One operating shaft 8 will be used to simultaneously move all of the switch members 5 for one cell, so that all of the contacts will be made or broken by the same operation and also by the same operation all of the anodes will receive polarizing current from the source 10 as soon as the cell is cut out of operation.
  • the method of protecting the cathodes of electrolytic cells, having anodes and a mercury cathode said anodes and said cathode being of substantially the same surface area, a main electrolysis circuit, and a source of polarizing current, when the cell is cut out of the main electrolysis current which comprises disconnecting said source of polarizing current from the anodes and cathode of said cell when the cell is in the main electrolysis circuit, automatically connecting said source of polarizing current, having a potential lower than the decomposition potential of the electrolysis solution to the electrolysis anodes and the mercury cathode of the cell when the cell is cut out of the main electrolysis circuit.
  • the method of protecting the cathode of an electrolytic cell having a set of anodes and a mercury cathode in the main electrolysis circuit, said anodes and said cathode being of substantially the same surface area, during periods, when the cell is disconnected from the main electrolysis current which comprises disconnecting a cell from the main electrolysis current while maintaining the current flowing through the other cells of the circuit, and substantially simultaneously connecting a small polarizing current having a potential lower than the decomposition potential of the electrolysis solution to said anodes and said cathode of said cell when said cell is cut out of the circuit.
  • a switching device for electrolytic cells comprising fixed and movable contacts, a rotary shaft, a movable contact member formed of a plurality of segments of a cylinder spaced closely adjacent to one another longitudinally of the axis of said shaft, springs spaced on each side of the axis of said rotary shaft pressing outwardly against each end of each of said segments, means to limit the outward movement of said segments by said springs, connections between said springs and said segments and the rotary shaft whereby rotary movement of said shaft causes rotary movement of said segments past said fixed contact members, said connections also permitting radial tipping movement of said segments relative to said shaft.
  • a switching device for electrolytic cells comprising a plurality of fixed contact members attached to bus bars of an electrolytic cell and forming an arc of a circle at their contact points, said fixed contact members being composed substantially of short sections of bus bar material, spring means pressing some of said contact members toward said arc of said circle, and movable contact members moving in the arc of said circle comprising a rotary shaft placed perpendicular to the arc of said circle formed by the fixed contact points, contact members formed of a plurality of segments of a cylinder spaced closely adjacent to one another longitudinally of the axis of said shaft, said segments of a cylinder having a length of arc sufficient to make contact with all of the three fixed contact point simultaneously, springs spaced on each side of the axis of said rotary shaft pressing out wardly against each end of each of said segments, means to limit the outward movement of said segments by said springs, connections between said springs and said seg- 7 ments and the rotary shaft whereby rotary movement of said shaft cause rotary movement of all of said segments

Landscapes

  • 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)
  • Connection Of Batteries Or Terminals (AREA)
US413332A 1953-03-02 1954-03-01 Method and apparatus for protecting the cathodes of electrolytic cells Expired - Lifetime US2834728A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT318436X 1953-03-02
IT191253X 1953-12-19

Publications (1)

Publication Number Publication Date
US2834728A true US2834728A (en) 1958-05-13

Family

ID=26327065

Family Applications (1)

Application Number Title Priority Date Filing Date
US413332A Expired - Lifetime US2834728A (en) 1953-03-02 1954-03-01 Method and apparatus for protecting the cathodes of electrolytic cells

Country Status (4)

Country Link
US (1) US2834728A (it)
CH (1) CH318436A (it)
DE (1) DE1046587B (it)
GB (1) GB785932A (it)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3293159A (en) * 1961-08-30 1966-12-20 Hooker Chemical Corp Process for producing a fused reducing bath for descaling
US3316125A (en) * 1964-09-21 1967-04-25 Tyco Laboratories Inc Electrochemical cells
US3396095A (en) * 1964-01-24 1968-08-06 Solvay Method and apparatus for the continuous regulation of the distance between the electrodes of electrolytic cells with liquid mecury cathodes
US3409519A (en) * 1964-10-10 1968-11-05 Oronzio De Nora Impianti Method of protecting electrolytic cells
US3475304A (en) * 1966-03-28 1969-10-28 Hooker Chemical Corp Cathodic protection of reinforcing metals in electrolytic cells
US3494850A (en) * 1965-10-04 1970-02-10 Solvay Short-circuiting device for electrolytic cell
US3847782A (en) * 1969-03-24 1974-11-12 Magyar Aluminium Busbar system for electrolysis cells
US3914170A (en) * 1973-03-19 1975-10-21 United Aircraft Corp Erosion prevention and fault detection for electrochemical machining apparatus
US4124465A (en) * 1972-07-18 1978-11-07 Swiss Aluminium Ltd. Protecting tube
US4285787A (en) * 1980-03-20 1981-08-25 Pulp And Paper Research Institute Of Canada Electrochemical corrosion protection of stainless steel bleach plant washers
US4561949A (en) * 1983-08-29 1985-12-31 Olin Corporation Apparatus and method for preventing activity loss from electrodes during shutdown
US4589966A (en) * 1985-10-03 1986-05-20 Olin Corporation Membrane cell jumper switch
US10400344B2 (en) 2013-06-05 2019-09-03 Outotec (Finland) Oy Apparatus for protection of anodes and cathodes in a system of electrolysis cells
US20230374682A1 (en) * 2020-10-12 2023-11-23 Siemens Energy Global GmbH & Co. KG Operating an electrolysis device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH95753A (de) * 1921-03-31 1922-08-01 Oerlikon Maschf Elektrische Kontaktvorrichtung.
GB221036A (en) * 1923-06-23 1924-09-04 Jacob Backus Improvements in and relating to electric switches
US1554090A (en) * 1924-12-29 1925-09-15 Hewitt John Herbert Electric switch
US1759991A (en) * 1927-06-02 1930-05-27 American Brown Boveri Electric Tap changer
US2227160A (en) * 1940-05-16 1940-12-31 Gen Electric Electric switch
US2508523A (en) * 1946-09-11 1950-05-23 Krebs & Co Device for the protection of the cathodes of electrolytic cells
FR974074A (fr) * 1941-12-06 1951-02-19 Cie Nat Matieres Colorantes Procédé et dispositif pour empêcher la corrosion des plots en fer ou en acier dans les cellules électrolytiques au repos

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH95753A (de) * 1921-03-31 1922-08-01 Oerlikon Maschf Elektrische Kontaktvorrichtung.
GB221036A (en) * 1923-06-23 1924-09-04 Jacob Backus Improvements in and relating to electric switches
US1554090A (en) * 1924-12-29 1925-09-15 Hewitt John Herbert Electric switch
US1759991A (en) * 1927-06-02 1930-05-27 American Brown Boveri Electric Tap changer
US2227160A (en) * 1940-05-16 1940-12-31 Gen Electric Electric switch
FR974074A (fr) * 1941-12-06 1951-02-19 Cie Nat Matieres Colorantes Procédé et dispositif pour empêcher la corrosion des plots en fer ou en acier dans les cellules électrolytiques au repos
US2508523A (en) * 1946-09-11 1950-05-23 Krebs & Co Device for the protection of the cathodes of electrolytic cells

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3293159A (en) * 1961-08-30 1966-12-20 Hooker Chemical Corp Process for producing a fused reducing bath for descaling
US3396095A (en) * 1964-01-24 1968-08-06 Solvay Method and apparatus for the continuous regulation of the distance between the electrodes of electrolytic cells with liquid mecury cathodes
US3316125A (en) * 1964-09-21 1967-04-25 Tyco Laboratories Inc Electrochemical cells
US3409519A (en) * 1964-10-10 1968-11-05 Oronzio De Nora Impianti Method of protecting electrolytic cells
US3494850A (en) * 1965-10-04 1970-02-10 Solvay Short-circuiting device for electrolytic cell
US3475304A (en) * 1966-03-28 1969-10-28 Hooker Chemical Corp Cathodic protection of reinforcing metals in electrolytic cells
US3847782A (en) * 1969-03-24 1974-11-12 Magyar Aluminium Busbar system for electrolysis cells
US4124465A (en) * 1972-07-18 1978-11-07 Swiss Aluminium Ltd. Protecting tube
US3914170A (en) * 1973-03-19 1975-10-21 United Aircraft Corp Erosion prevention and fault detection for electrochemical machining apparatus
US4285787A (en) * 1980-03-20 1981-08-25 Pulp And Paper Research Institute Of Canada Electrochemical corrosion protection of stainless steel bleach plant washers
US4561949A (en) * 1983-08-29 1985-12-31 Olin Corporation Apparatus and method for preventing activity loss from electrodes during shutdown
US4589966A (en) * 1985-10-03 1986-05-20 Olin Corporation Membrane cell jumper switch
US10400344B2 (en) 2013-06-05 2019-09-03 Outotec (Finland) Oy Apparatus for protection of anodes and cathodes in a system of electrolysis cells
US20230374682A1 (en) * 2020-10-12 2023-11-23 Siemens Energy Global GmbH & Co. KG Operating an electrolysis device

Also Published As

Publication number Publication date
DE1046587B (de) 1958-12-18
GB785932A (en) 1957-11-06
CH318436A (it) 1957-01-15

Similar Documents

Publication Publication Date Title
US2834728A (en) Method and apparatus for protecting the cathodes of electrolytic cells
US2508523A (en) Device for the protection of the cathodes of electrolytic cells
CA2118245A1 (en) Anode-cathode arrangement for aluminum production cells
ES450933A1 (es) Aparato para electrolisis.
PL95784B1 (pl) Uklad elektrolizerow z elektrodami pionowymi
CN103384732A (zh) 大型电解槽和电解停止方法
ES8200410A1 (es) Procedimiento y dispositivo para la supresion de perturba- ciones magneticas en cubas de electrolisis de intensidad muyelevada colocadas a lo ancho
US3915817A (en) Method of maintaining cathodes of an electrolytic cell free of deposits
CA2483245A1 (en) Process and apparatus for smelting aluminum
US4078984A (en) Circuit of monopolar electrolytic cells
US588276A (en) Carl kellner
US3140991A (en) Mercury cathode electrolytic cells
US3594300A (en) Apparatus for indicating and eliminating short circuits in the cells of electrolysis plants
US2576553A (en) Electrolytic cells
GB1396019A (en) Electrolytic cell assembly
AU2017245752B2 (en) Method and arrangement for controlling the electrical circuit in an electrolytic process
US1585716A (en) Preparation of sodium
US5207883A (en) Jumper switch means
US3256162A (en) Method for the electrolytic production of metal hydroxides
GB903426A (en) Electrolytic production of metal hydroxide
US857378A (en) Electrolytically refining metals.
JPH07150382A (ja) 電気的に直列接続された電界槽用のジャンパスイッチ装置
DE2538414C2 (de) Elektrolyseapparat zur Herstellung von Chlor aus wässriger Alkalihalogenidlösung
US592782A (en) Chemical-electric generator
US3481853A (en) Method and apparatus for cleaning fuel cell electrolytes