EP1070158B2 - Fused bath electrolysis cell for producing aluminium by hall-heroult process comprising cooling means - Google Patents

Fused bath electrolysis cell for producing aluminium by hall-heroult process comprising cooling means Download PDF

Info

Publication number
EP1070158B2
EP1070158B2 EP99911893A EP99911893A EP1070158B2 EP 1070158 B2 EP1070158 B2 EP 1070158B2 EP 99911893 A EP99911893 A EP 99911893A EP 99911893 A EP99911893 A EP 99911893A EP 1070158 B2 EP1070158 B2 EP 1070158B2
Authority
EP
European Patent Office
Prior art keywords
air
cell
cooling
localized
air blast
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
EP99911893A
Other languages
German (de)
French (fr)
Other versions
EP1070158A1 (en
EP1070158B1 (en
Inventor
Jérôme BOS
Benoît FEVE
Pierre Homsi
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.)
Rio Tinto France SAS
Original Assignee
Aluminium Pechiney SA
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=9525541&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP1070158(B2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Aluminium Pechiney SA filed Critical Aluminium Pechiney SA
Priority to SI9930491T priority Critical patent/SI1070158T2/en
Publication of EP1070158A1 publication Critical patent/EP1070158A1/en
Application granted granted Critical
Publication of EP1070158B1 publication Critical patent/EP1070158B1/en
Publication of EP1070158B2 publication Critical patent/EP1070158B2/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
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C25C3/20—Automatic control or regulation of cells

Definitions

  • the invention relates to the production of aluminum by igneous electrolysis according to the Hall-Héroult process and the installations intended for the industrial implementation of this process.
  • the invention relates more specifically to controlling the heat flows of the electrolysis cells and the cooling means that make it possible to obtain this control.
  • Aluminum metal is produced industrially by igneous electrolysis, namely by electrolysis of alumina in solution in a bath of molten cryolite, called electrolyte bath, according to the well-known Hall-Héroult process.
  • the electrolyte bath is contained in a tank comprising a steel box, which is lined internally with refractory and / or insulating materials, and a cathode assembly located at the bottom of the tank.
  • the electrolysis current which can reach values of more than 300 kA, operates the alumina reduction reactions and also makes it possible to maintain the electrolyte bath at a temperature of the order of 950 ° C. by Joule effect. .
  • the electrolytic cell is generally controlled in such a way that it is in thermal equilibrium, that is to say that the heat dissipated by the electrolysis cell is generally compensated by the heat produced in the cell, which comes from essentially electrolysis current.
  • the thermal equilibrium point is generally selected so as to achieve the most favorable operating conditions from a not only technical but also economic point of view.
  • the possibility of maintaining an optimal setpoint temperature represents a significant saving in the cost of producing aluminum due to the fact that the Faraday yield is maintained at a very high value, which reaches values higher than 90% in the most efficient plants. performance.
  • the thermal equilibrium conditions depend on the physical parameters of the tank, such as the dimensions and the nature of the constituent materials, and the operating conditions of the tank, such as the electrical resistance of the tank, the temperature of the bath or the intensity of the electrolysis current.
  • the tank is often constituted and conducted so as to cause the formation of a solidified bath slope on the side walls of the tank, which in particular makes it possible to inhibit the attack of the coatings of said walls by the liquid cryolite.
  • the igneous electrolysis aluminum production industry in the framework of optimized plant management, is regularly confronted with the need for industrial facilities which not only allow the stabilization and maintenance of the operating point of electrolysis tanks, but which also admit voluntary variations in operating conditions that may be important compared to the nominal conditions.
  • it is often useful to be able to easily control or even modulate the operating point of the electrolysis cells of a plant, while maintaining or even improving their normal technical performance, without degrading as far as production costs.
  • Such a situation occurs, for example, when one seeks to vary the power of a series of electrolysis cells according to a contract of electrical energy.
  • the Applicant has researched methods and means for controlling the thermal flows and for stabilizing the thermal regime of the electrolysis cells, which, while offering a very high efficiency and adaptability, do not require a investment and do not result in prohibitive additional operating costs.
  • the US patent US 4,608,135 proposes to use a tank comprising passages arranged between the edge slabs and the insulator inside the box, and intake ports of air on the sides of the tank.
  • the passages communicate on the one hand with said orifices and on the other hand with the inside of the collection device attached to the tank.
  • the collection device draws ambient air taken from the sides of the tank through said orifices and causes its flow in said passages along the edge slabs, which has the effect of cooling them.
  • the airflow is controlled by means of valved openings on the sides of the collector, which act as bypass ducts.
  • This device requires significant modifications of the tank and does not allow independent control of the cooling, because the regular interventions on the tank require the opening of the hoods of the capture device which disturb the effect of the valves.
  • the plaintiff has set itself the goal of finding means, effective and adaptable, to evacuate and dissipate the heat produced by the electrolytic cell, which can easily be put in place and which do not require any major modifications of the tank, and in particular of the caisson, nor an important infrastructure.
  • the applicant has particularly sought ways to change the potency of the tanks, which easily adapt to different types of tank or different modes of operating a same type of tank, and which are suitable for industrial installations with a large number of tanks in series.
  • the first object of the invention is an electrolysis cell for the production of aluminum by the Hall-Héroult electrolysis process which comprises localized air blast cooling means distributed according to claim 1.
  • the second object of the invention is an aluminum production plant by the Hall-Héroult electrolysis process characterized in that it comprises tanks according to the invention.
  • the electrolysis cell for the production of aluminum by the Hall-Héroult electrolysis method according to the invention comprises a steel box, internal coating elements and a cathode assembly, and is characterized in that it comprises local jet air cooling means distributed around the casing according to claim 1.
  • the air is blown, that is to say that the circuit is open and lost flow.
  • the air flow projected on the surface is then diluted in the ambient air, so that it is not essential to add special means for cooling the air that has been heated in contact with the walls. .
  • the blowing of air in the form of localized jets that is to say the projection of air in the form of substantially directional and confined flows, thus striking the caisson on a relatively small surface, enables the wall of the chamber to be cooled effectively.
  • the jets are distributed around the box so as to fix the preferential cooling zones on the surface of the box, these areas being advantageously determined according to the thermal profile of the tank, in particular to increase the overall efficiency of the cooling.
  • Said cooling means are more specifically characterized in that they comprise means for blowing air to cool the box, that is to say to evacuate and dissipate the heat produced by the tank at the caisson, said means of blowing forming localized jets, and in that they comprise means for distributing the jets around the box in a predetermined distribution.
  • the invention thus makes it possible to control or modulate the power of the electrolysis cells by adding or adding efficient and adaptable cooling means, which can optionally take the form of a fixed or variable cooling power booster by compared to the nominal power.
  • the invention thus offers the possibility of modifying the power of each tank individually.
  • the air flow of the blowing means according to the invention may be variable, so as to allow a finer control of the cooling, or possibly a cooling control. It is also advantageous to be able to integrate the means according to the invention with the control systems which equip the most modern electrolysis cells.
  • the cooling means can then be controlled, or even controlled, by the control system of the tank, so that the heat flow can be regulated more efficiently and, optionally, automatically.
  • the tank may comprise complementary cooling means, such as static cooling means.
  • the cooling means are optionally removable, in that they can be easily put in place or removed from the tank, in some cases even when it is in operation. Thus, for example, during the rehabilitation of a tank, the cooling means may be wholly or partially removed, which facilitates access to the box and the maintenance work.
  • the cooling means according to the invention in the form of a cooling device in whole or in part autonomous. Such an assembly can then lead to a globalized design and greater ease of operation.
  • the general air flow rate of said device may be variable.
  • the cooling means comprise air distribution means, for distributing the flow of air around the box, a means of air discharge, which allows the air to be forced back into the air distribution means, and localized blowing means, which project air locally in the form of jets, said localized blowing means being arranged at specific locations of the box.
  • the distribution means preferably comprise channeling means, such as pipes.
  • the localized blowing means may be nozzles, ejectors, horns, nozzles or pipes.
  • the localized blowing means are advantageously distributed along the channeling means.
  • the air flow of the discharge means may be variable.
  • the air flow of one or more localized blowing means may also be individually variable.
  • the aluminum production plant by the Hall-Héroult electrolysis method according to the second subject of the invention is characterized in that it comprises tanks according to the first subject of the invention.
  • the tanks can be individually equipped with cooling means according to the invention.
  • the tanks can be individually equipped with the cooling device according to the invention, which can optionally be controlled centrally.
  • the electrolysis cells are grouped or arranged in series.
  • the tanks may advantageously be equipped with cooling means according to the invention, which are wholly or partly common to two or more tanks, that is to say that two or more tanks have in common the one of said cooling means.
  • the electrolysis cell (1) for the production of aluminum by the Hall-Heroult electrolysis method according to the invention comprises a box (2) made of steel, internal coating elements (3) and a cathode assembly (4). ), and local jet air cooling means distributed around the housing (2).
  • the lining elements (3) are generally blocks of refractory materials, which may be thermal insulators.
  • the cathode assembly (4) comprises connecting bars (9) to which are fixed the electrical conductors for the routing of the electrolysis current.
  • the coating elements and the cathode assembly form a crucible inside the tank, which crucible makes it possible to contain the electrolyte bath (7) and the sheet of liquid metal (6) when the tank is in charge.
  • the anodes (11) are partially immersed in the electrolyte bath (7).
  • the electrolyte bath contains dissolved alumina and, in general, a blanket of alumina (8) covers the electrolyte bath.
  • the aluminum metal (6) produced during the electrolysis accumulates at the bottom of the tank, so that there is a fairly clear interface between the molten metal (6) and the molten cryolite bath (7).
  • the position of this bath-metal interface varies over time: it rises as the liquid metal accumulates at the bottom of the tank and lowers when liquid metal is removed from the tank.
  • the conduct of the electrolysis cells is generally carried out by the control of several parameters, such as the concentration of alumina of the electrolyte, the temperature of the electrolyte bath, the total height of the bath or the position of the anodes.
  • concentration of alumina of the electrolyte As a rule, it is sought to form a solidified cryolite bank (5) on the part of the side walls (12) of the crucible which are in contact with the electrolyte bath (7) and with the sheet of liquid metal (6) .
  • Said walls are often made of edge slabs made of carbonaceous material or based on carbon compounds, such as an SiC-based refractory, and broth pasta.
  • the side walls may comprise preformed blocks or sides, preferably homogeneous, made of a material of high thermal conductivity, at least higher than that of the pasta doughs. and more preferably at least equal to that of the curb slabs normally used, such as for example a material based on SiC.
  • the tank is also provided with a collection device for capturing and recovering the gaseous effluents emitted by the electrolyte bath during the electrolysis.
  • the sensing device comprises on the entire vessel a cowling (10) generally provided with opening covers and access.
  • the cooling means comprise ducting means (28), such as ducts (21-24), discharge means (25) for discharging air into said means. pipe, and localized blowing means (27) for projecting the air in the form of localized jets.
  • ducting means such as ducts (21-24)
  • discharge means for discharging air into said means. pipe
  • localized blowing means for projecting the air in the form of localized jets.
  • These means preferably form a cooling device (20).
  • the channeling means (28) can be held in position by different means. In particular, they can be attached to the structural elements or reinforcement of the tank, such as stiffeners, which can be modified or adapted for this purpose.
  • the channeling means (28) can also be leaned against the caisson or placed against it ci, or fixed to the edge of the box.
  • the general air flow rate of the device (20) can advantageously be variable, for example by means of valves or by a variation of the flow rate of the discharge means (25).
  • the air flow of one or more localized blowing means may also be variable, possibly individually, with possibly also the possibility of reducing to zero the flow of certain blowing means.
  • the air can in some cases be pulsed.
  • the cooling means, or the cooling device, according to the invention are optionally entirely or partially removable.
  • the pipes can be easily dismountable and transportable, thanks in particular to a sectional design and to appropriate assembly means.
  • the air discharged into the channeling means is blown on the walls of the box, at predetermined locations, by means of localized blowing means (27), which are advantageously distributed along the channeling means.
  • the localized blowing means are not necessarily distributed uniformly over the surface of the box; it may sometimes be preferable to concentrate them in particular areas.
  • the localized blowing means (27) make it possible to direct the flow of air at precise locations in the box, for example at the height of the electrolyte bath (7). It is advantageous for one or more localized blowing means (27) to be orientable.
  • the localized blowing means project the blown air at a speed, called the ejection speed, which is preferably between 10 and 100 m / s, and more preferably between 20 and 70 m / s.
  • the number, the position and the dimensions of the localized blowing means (27), the power of the delivery means (25), as well as the configuration and the dimensions of the channeling means (21 to 24) are chosen so that the air flow is sufficient to allow efficient cooling and to ensure a determined cooling power at the selected blowing points, taking into account in particular the network aeraulic.
  • the air discharge means (25) may be a fan, which delivers from the ambient air, or a compressed air blower, such as a fan-trunk, or a compressed air system or a compressed air system. air overheated.
  • an electrical isolation means such as a conducting section. electrical insulating material.
  • the pipes (21-24) may be made of metal materials, preferably non-magnetic (such as non-magnetic stainless steel or aluminum), or insulating materials (such as glass fibers), or a combination of these (such as a metal duct provided with an insulating sheath).
  • non-magnetic such as non-magnetic stainless steel or aluminum
  • insulating materials such as glass fibers
  • the cooling device (20) can optionally be controlled by the general control system of the tank, so as to ensure a more efficient centralized overall control.
  • the tank may also be provided with complementary cooling means, in particular static cooling means, such as fins or equivalent means.
  • complementary cooling means in particular static cooling means, such as fins or equivalent means.
  • the channeling means form shoots, that is to say they are constituted such that a main channeling means (21) branched in horizontal branches under the tank (22), vertical on the sides and the tank heads (23) and horizontal on the sides and the tank heads (24).
  • a main channeling means (21) branched in horizontal branches under the tank (22), vertical on the sides and the tank heads (23) and horizontal on the sides and the tank heads (24).
  • This configuration ensures a satisfactory a Vogellic balancing of the pipe network and facilitates the installation of the cooling device.
  • the vertical branches can be placed between the cathode bars (9).
  • the channeling means (28) surround or wholly or partially surround the box (2) of the electrolytic cell.
  • a single discharge means (25) is common to more than one tank, and more specifically to two or more tanks of a plant.
  • the delivery means (25) distributes the airflow through a network (29) comprising a common main duct (30) and a connection point (31) for each tank.
  • the connection points are optionally equipped with valves to isolate each tank individually and venting to rebalance the distribution of air flows. Valves and venting are particularly useful during interventions on a particular tank or on some of them since they allow to isolate the tank or tanks concerned while preserving satisfactory air flow rates for them. other tanks connected to the network.
  • the cooling means are advantageously controlled or controlled by means of a control system common to more than one tank.
  • each tank provided with own cooling means or each group of tanks provided with cooling means having elements in common can be controlled by a so-called first level control system, and all Vats or groups of vats of a particular electrolysis hall of the plant can, moreover, be controlled globally by a so-called second-level control system.
  • a main pipe (21) passes longitudinally under the box (2) to near the center of the tank, then divides into three branches (22a, 22b, 22c) perpendicular to each other and of smaller section than the main pipe;
  • a longitudinal branch (22a) extends under the box to the other end thereof, then forms a vertical branch (23a), which goes up along the tank head to the height of the slab border, approximately, then branches in two horizontal branches (24a, 24a ') which extend to the side edges of the tank;
  • a vertical branch (23c) equivalent to the branch (23a) is connected directly to the main pipe, and also branched into two horizontal
  • Nozzles (27) have been arranged uniformly along the branches. According to the tests, the number of nozzles was 5 to 8 nozzles along each head of the tank and 15 to 20 nozzles on each tank side. The nozzles were directed approximately to the theoretical bath-metal level in most tests. In some tests, some nozzles were directed to structural reinforcement elements of the box, which served as cooling fins.
  • the pipes and nozzles were made of steel, and partly of stainless steel.
  • the air discharge means (25) was, in some tests, a mechanical fan and, in other tests, a fan-horn.
  • the cooling devices were provided with means for varying the air flow.
  • thermocouples and pyrometers showed that the device made it possible to obtain average temperature decreases of 50 to 100 ° C at the height of the side walls. Cooling control was easily achieved by varying the amount of discharge air.
  • the cooling means make it possible to evacuate and dissipate the heat energy produced in the electrolytic cell, by an optimal control of certain thermal flows, which can be adapted to different climatic and / or operating conditions of the tank, which can significantly deviate from nominal conditions or standard.
  • the cooling means furthermore make it possible to control, with precision, the formation of the solidified cryolite bath slope.
  • the cooling means or the cooling device according to the invention can easily be adapted to any type of tank and to different environments. They can easily be installed on existing tanks, especially in the context of their refurbishment, the integration of a thermal regulation and / or a change in the nominal intensity. More specifically, the invention facilitates modulations of the power of the tanks which allow to take into account, for example, technical, economic and / or contractual constraints. In particular, the invention allows an increase in the nominal intensity of existing tanks, without causing premature degradation of the tanks.
  • the possibility of adapting the tank to the means, or the cooling device, as well as its operating conditions makes it possible to optimize the driving of several tanks at a time, even a complete series of tanks, so in particular to standardize the point of operation of the tanks.
  • the invention allows an individualized thermal control of the vats of a plant, which is often necessary in factories with high productivity. This is the case, for example, during the transient phases that occur when certain vats of the same series have new or different solders from those of the rest of the series.
  • the invention also allows the modernization of existing plants without the need for infrastructure work that would make such operations prohibitive.
  • the invention also makes it possible to prolong the life of a tank at the end of its life, whose casing has abnormal hot spots.

Description

Domaine de l'inventionField of the invention

L'invention concerne la production d'aluminium par électrolyse ignée selon le procédé Hall-Héroult et les installations destinées à la mise en oeuvre industrielle de ce procédé. L'invention concerne plus spécifiquement le contrôle des flux thermiques des cuves d'électrolyse et les moyens de refroidissement qui permettent d'obtenir ce contrôle.The invention relates to the production of aluminum by igneous electrolysis according to the Hall-Héroult process and the installations intended for the industrial implementation of this process. The invention relates more specifically to controlling the heat flows of the electrolysis cells and the cooling means that make it possible to obtain this control.

Etat de la techniqueState of the art

L'aluminium métal est produit industriellement par électrolyse ignée, à savoir par électrolyse de l'alumine en solution dans un bain de cryolithe fondue, appelé bain d'électrolyte, selon le procédé bien connu de Hall-Héroult. Le bain d'électrolyte est contenu dans une cuve comprenant un caisson en acier, qui est revêtu intérieurement de matériaux réfractaires et/ou isolants, et un ensemble cathodique situé au fond de la cuve. Le courant d'électrolyse, qui peut atteindre des valeurs de plus de 300 kA, opère les réactions de réduction de l'alumine et permet également de maintenir le bain d'électrolyte à une température de l'ordre de 950 °C par effet Joule.Aluminum metal is produced industrially by igneous electrolysis, namely by electrolysis of alumina in solution in a bath of molten cryolite, called electrolyte bath, according to the well-known Hall-Héroult process. The electrolyte bath is contained in a tank comprising a steel box, which is lined internally with refractory and / or insulating materials, and a cathode assembly located at the bottom of the tank. The electrolysis current, which can reach values of more than 300 kA, operates the alumina reduction reactions and also makes it possible to maintain the electrolyte bath at a temperature of the order of 950 ° C. by Joule effect. .

La cuve d'électrolyse est généralement pilotée de telle manière qu'elle se trouve en équilibre thermique, c'est-à-dire que la chaleur dissipée par la cuve d'électrolyse est globalement compensée par la chaleur produite dans la cuve, qui provient essentiellement du courant d'électrolyse. Le point d'équilibre thermique est généralement choisi de manière à atteindre les conditions de fonctionnement les plus favorables d'un point de vue non seulement technique, mais également économique. En particulier, la possibilité de maintenir une température de consigne optimale constitue une économie appréciable du coût de production de l'aluminium du fait du maintien du rendement Faraday à une valeur très élevée, qui atteint des valeurs supérieures à 90 % dans les usines les plus performantes.The electrolytic cell is generally controlled in such a way that it is in thermal equilibrium, that is to say that the heat dissipated by the electrolysis cell is generally compensated by the heat produced in the cell, which comes from essentially electrolysis current. The thermal equilibrium point is generally selected so as to achieve the most favorable operating conditions from a not only technical but also economic point of view. In particular, the possibility of maintaining an optimal setpoint temperature represents a significant saving in the cost of producing aluminum due to the fact that the Faraday yield is maintained at a very high value, which reaches values higher than 90% in the most efficient plants. performance.

Les conditions d'équilibre thermique dépendent des paramètres physiques de la cuve, tels que les dimensions et la nature des matériaux constitutifs, et des conditions de fonctionnement de la cuve, tels que la résistance électrique de la cuve, la température du bain ou l'intensité du courant d'électrolyse. La cuve est souvent constituée et conduite de façon à entraîner la formation d'un talus de bain solidifié sur les parois latérales de la cuve, ce qui permet notamment d'inhiber l'attaque des revêtements desdites parois par la cryolithe liquide.The thermal equilibrium conditions depend on the physical parameters of the tank, such as the dimensions and the nature of the constituent materials, and the operating conditions of the tank, such as the electrical resistance of the tank, the temperature of the bath or the intensity of the electrolysis current. The tank is often constituted and conducted so as to cause the formation of a solidified bath slope on the side walls of the tank, which in particular makes it possible to inhibit the attack of the coatings of said walls by the liquid cryolite.

Problème poséProblem

L'industrie de la production d'aluminium par électrolyse ignée, dans le cadre d'une gestion optimisée des usines, est régulièrement confrontée à la nécessité de disposer d'installations industrielles qui non seulement permettent la stabilisation et le maintien du point de fonctionnement des cuves d'électrolyse, mais qui admettent également des variations volontaires des conditions de fonctionnement qui peuvent être importantes par rapport aux conditions nominales. En d'autres termes, il est souvent utile de pouvoir aisément contrôler, voire de moduler, le point de fonctionnement des cuves d'électrolyse d'une usine, tout en conservant, voire en améliorant, leurs performances techniques normales, sans dégrader pour autant les coûts de production. Une telle situation se produit, par exemple, lorsqu'on cherche à varier la puissance d'une série de cuves d'électrolyse en fonction d'un contrat d'énergie électrique.The igneous electrolysis aluminum production industry, in the framework of optimized plant management, is regularly confronted with the need for industrial facilities which not only allow the stabilization and maintenance of the operating point of electrolysis tanks, but which also admit voluntary variations in operating conditions that may be important compared to the nominal conditions. In other words, it is often useful to be able to easily control or even modulate the operating point of the electrolysis cells of a plant, while maintaining or even improving their normal technical performance, without degrading as far as production costs. Such a situation occurs, for example, when one seeks to vary the power of a series of electrolysis cells according to a contract of electrical energy.

Dans le cadre de cet objectif, la demanderesse a recherché des méthodes et moyens pour contrôler les flux thermiques et pour stabiliser le régime thermique des cuves d'électrolyse, qui, tout en offrant une très grande efficacité et une grande adaptabilité, ne requièrent pas un investissement élevé et n'entraînent pas des coûts de fonctionnement supplémentaires rédhibitoires.In the context of this objective, the Applicant has researched methods and means for controlling the thermal flows and for stabilizing the thermal regime of the electrolysis cells, which, while offering a very high efficiency and adaptability, do not require a investment and do not result in prohibitive additional operating costs.

Il a déjà été proposé de munir les cuves de moyens spécifiques pour évacuer et dissiper, de manière contrôlée, la chaleur produite par les cuves d'électrolyse. En particulier, les certificats d'auteur d'invention soviétiques SU 605 865 et SU 663 760 proposent de munir les cuves d'un système de refroidissement, commandé de l'extérieur, qui comprend des cavités hermétiques sur les côtés et en dessous de la cuve, des écrans thermiques variables et des conduites munies de clapets de régulation. De l'air est refoulé dans les conduites par un ventilateur ou un compresseur Ces dispositifs requièrent une infrastructure importante et encombrante.It has already been proposed to provide the tanks with specific means for evacuating and dissipating, in a controlled manner, the heat produced by the electrolysis tanks. In particular, Soviet invention certificates SU 605 865 and SU 663 760 propose to provide the vats with a cooling system, controlled from the outside, which includes hermetic cavities on the sides and below the tank, variable heat shields and pipes equipped with regulating valves. Air is forced back into the pipes by a fan or a compressor These devices require a large and bulky infrastructure.

Il a par ailleurs été proposé, par la demande de brevet EP 0 047 227 , de renforcer l'isolation thermique de la cuve et de la munir de caloducs équipés d'échangeurs thermiques. Les caloducs traversent le caisson et l'isolant thermique et sont fichés dans les parties carbonées, telles que les dalles de bordure. Cette solution est de mise en oeuvre assez complexe et coûteuse, et entraîne de surcroît des modifications assez importantes de la cuve.It was also proposed, by the request of EP 0 047 227 , to reinforce the thermal insulation of the tank and to provide it with heat pipes equipped with heat exchangers. The heat pipes pass through the caisson and the thermal insulation and are stuck in the carbon parts, such as the edge slabs. This solution is quite complex and expensive to implement, and moreover causes quite significant changes in the tank.

Afin de favoriser plus spécifiquement la formation d'un talus de bain solidifié, il est par ailleurs connu, par le brevet américain US 4 087 345 , d'utiliser un caisson muni de raidisseurs et d'un cadre de renforcement constitués de manière à favoriser le refroidissement des côtés de cuve par convection naturelle d'air ambiant. Un tel dispositif exige des installations solidaires du caisson. En outre, les dispositifs statiques ne se prêtent pas aisément à un contrôle précis des flux thermiques.In order more specifically to promote the formation of a solidified bathing slope, it is moreover known, by the American patent US 4,087,345 , to use a box provided with stiffeners and a reinforcing frame constituted so as to promote the cooling of the sides of the tank by natural convection of ambient air. Such a device requires fixed installations of the box. In addition, the static devices do not lend themselves easily to a precise control of heat flows.

Dans le but de contrôler la formation du talus de bain solidifié et de récupérer une partie de la chaleur retirée au niveau des côtés de la cuve, le brevet américain US 4 608 135 propose d'utiliser une cuve comprenant des passages disposés entre les dalles de bordures et l'isolant intérieur du caisson, et des orifices d'admission d'air sur les côtés de la cuve. Les passages communiquent d'une part avec lesdits orifices et d'autre part avec l'intérieur du dispositif de captage fixé sur la cuve. Le dispositif de captage aspire l'air ambiant prélevé sur les côtés de la cuve par lesdits orifices et entraîne son écoulement dans lesdits passages, le long des dalles de bordure, ce qui a pour effet de les refroidir. Le débit d'air est contrôlé à l'aide d'ouvertures munies de clapets et situées sur les côtés du dispositif de captage, qui agissent en tant que conduits de dérivation ("bypass" en anglais). Ce dispositif exige des modifications importantes de la cuve et ne permet pas un contrôle indépendant du refroidissement, car les interventions régulières sur la cuve nécessitent l'ouverture des capots du dispositif de captage qui perturbent l'effet des clapets.In order to control the formation of the solidified bathing slope and recover some of the heat removed at the sides of the tank, the US patent US 4,608,135 proposes to use a tank comprising passages arranged between the edge slabs and the insulator inside the box, and intake ports of air on the sides of the tank. The passages communicate on the one hand with said orifices and on the other hand with the inside of the collection device attached to the tank. The collection device draws ambient air taken from the sides of the tank through said orifices and causes its flow in said passages along the edge slabs, which has the effect of cooling them. The airflow is controlled by means of valved openings on the sides of the collector, which act as bypass ducts. This device requires significant modifications of the tank and does not allow independent control of the cooling, because the regular interventions on the tank require the opening of the hoods of the capture device which disturb the effect of the valves.

Il est également connu de l'article de H. Kvande intitulé "Common cathode failures and remedies" publié dans "8th International light metals congress", Leoben-Vienna, 1987, pp 160-162 de refroidir des cotés rouges d'une cuve d'électrolyse par de l'air pressurisé.It is also known from the article of H. Kvande entitled "Common cathode failures and remedies" published in "8th International light metals congress", Leoben-Vienna, 1987, pp 160-162 to cool red sides of an electrolytic cell with pressurized air.

Ayant constaté l'absence de solutions connues satisfaisantes, la demanderesse s'est fixé pour objectif de trouver des moyens, efficaces et adaptables, pour évacuer et dissiper la chaleur produite par la cuve d'électrolyse, qui puissent aisément être mis en place et qui ne nécessitent ni des modifications importantes de la cuve, et notamment du caisson, ni une infrastructure importante. En vue d'une utilisation aussi bien dans les usines existantes que dans les nouvelles usines, la demanderesse a recherché tout particulièrement des moyens qui permettent de modifier la puissance des cuves, qui s'adaptent aisément à différents types de cuve ou à différents modes de fonctionnement d'un même type de cuve, et qui se prêtent à des installations industrielles comportant un grand nombre de cuves en série.Having noted the absence of satisfactory known solutions, the plaintiff has set itself the goal of finding means, effective and adaptable, to evacuate and dissipate the heat produced by the electrolytic cell, which can easily be put in place and which do not require any major modifications of the tank, and in particular of the caisson, nor an important infrastructure. With a view to use both in existing factories and in new factories, the applicant has particularly sought ways to change the potency of the tanks, which easily adapt to different types of tank or different modes of operating a same type of tank, and which are suitable for industrial installations with a large number of tanks in series.

Objets de l'inventionObjects of the invention

Le premier objet de l'invention est une cuve d'électrolyse pour la production d'aluminium par le procédé d'électrolyse Hall-Héroult qui comprend des moyens de refroidissement par soufflage d'air à jets localisés et répartis selon la revendication 1.The first object of the invention is an electrolysis cell for the production of aluminum by the Hall-Héroult electrolysis process which comprises localized air blast cooling means distributed according to claim 1.

Le deuxième objet de l'invention est une usine de production d'aluminium par le procédé d'électrolyse Hall-Héroult caractérisée en ce qu'elle comprend des cuves selon l'invention.The second object of the invention is an aluminum production plant by the Hall-Héroult electrolysis process characterized in that it comprises tanks according to the invention.

Description de l'inventionDescription of the invention

La cuve d'électrolyse pour la production d'aluminium par le procédé d'électrolyse Hall-Héroult selon l'invention comprend un caisson en acier, des éléments de revêtement intérieur et un ensemble cathodique, et est caractérisée en ce qu'elle comprend des moyens de refroidissement par soufflage d'air à jets localisés répartis autour du caisson selon la revendication 1.The electrolysis cell for the production of aluminum by the Hall-Héroult electrolysis method according to the invention comprises a steel box, internal coating elements and a cathode assembly, and is characterized in that it comprises local jet air cooling means distributed around the casing according to claim 1.

Ainsi, selon l'invention, l'air est soufflé, c'est-à-dire que le circuit est ouvert et à flux perdu. Le flux d'air projeté sur la surface se dilue ensuite dans l'air ambiant, de sorte qu'il n'est pas indispensable d'ajouter des moyens particuliers pour refroidir l'air projeté, qui s'est réchauffé au contact des parois.Thus, according to the invention, the air is blown, that is to say that the circuit is open and lost flow. The air flow projected on the surface is then diluted in the ambient air, so that it is not essential to add special means for cooling the air that has been heated in contact with the walls. .

Le soufflage d'air sous forme de jets localisés, c'est-à-dire la projection d'air sous forme de flux sensiblement directionnels et confinés, percutant ainsi le caisson sur une surface relativement réduite, permet de refroidir efficacement la paroi de la cuve à des endroits déterminés. Les jets sont répartis autour du caisson de manière à fixer les zones de refroidissement préférentielles sur la surface du caisson, ces zones étant avantageusement déterminées en fonction du profil thermique de la cuve, dans le but notamment d'augmenter l'efficacité globale du refroidissement.The blowing of air in the form of localized jets, that is to say the projection of air in the form of substantially directional and confined flows, thus striking the caisson on a relatively small surface, enables the wall of the chamber to be cooled effectively. tank at specific locations. The jets are distributed around the box so as to fix the preferential cooling zones on the surface of the box, these areas being advantageously determined according to the thermal profile of the tank, in particular to increase the overall efficiency of the cooling.

Lesdits moyens de refroidissement sont plus précisément caractérisés en qu'ils comprennent des moyens de soufflage d'air pour refroidir le caisson, c'est-à-dire pour évacuer et dissiper la chaleur produite par la cuve au niveau du caisson, lesdits moyens de soufflage formant des jets localisés, et en ce qu'ils comprennent des moyens pour répartir les jets autour du caisson suivant une répartition déterminée.Said cooling means are more specifically characterized in that they comprise means for blowing air to cool the box, that is to say to evacuate and dissipate the heat produced by the tank at the caisson, said means of blowing forming localized jets, and in that they comprise means for distributing the jets around the box in a predetermined distribution.

L'invention permet ainsi le contrôle ou la modulation de la puissance des cuves d'électrolyse par adjonction ou ajout de moyens de refroidissement efficaces et adaptables, qui peut éventuellement prendre la forme d'un appoint de puissance de refroidissement, fixe ou variable, par rapport à la puissance nominale. L'invention offre ainsi la possibilité de modifier la puissance de chaque cuve individuellement.The invention thus makes it possible to control or modulate the power of the electrolysis cells by adding or adding efficient and adaptable cooling means, which can optionally take the form of a fixed or variable cooling power booster by compared to the nominal power. The invention thus offers the possibility of modifying the power of each tank individually.

Le débit d'air des moyens de soufflage selon l'invention peut être variable, de manière à permettre un contrôle plus fin du refroidissement, voire éventuellement une régulation du refroidissement. Il est également avantageux de pouvoir intégrer les moyens selon l'invention aux systèmes de régulation qui équipent les cuves d'électrolyse les plus modernes. Les moyens de refroidissement peuvent alors être contrôlés, voire pilotés, par le système de régulation de la cuve, de sorte que le flux thermique puisse être régulé plus efficacement et, éventuellement, de manière automatisée.The air flow of the blowing means according to the invention may be variable, so as to allow a finer control of the cooling, or possibly a cooling control. It is also advantageous to be able to integrate the means according to the invention with the control systems which equip the most modern electrolysis cells. The cooling means can then be controlled, or even controlled, by the control system of the tank, so that the heat flow can be regulated more efficiently and, optionally, automatically.

La cuve peut comprendre des moyens de refroidissement complémentaires, tels que des moyens de refroidissement statiques.The tank may comprise complementary cooling means, such as static cooling means.

Les moyens de refroidissement sont éventuellement amovibles, en ce sens qu'ils peuvent être aisément mis en place ou retirés de la cuve, dans certains cas même lorsque celle-ci est en fonctionnement. Ainsi, par exemple, lors de la remise en état d'une cuve, les moyens de refroidissement peuvent être en tout ou partie retirés, ce qui facilite l'accès au caisson et le travail d'entretien.The cooling means are optionally removable, in that they can be easily put in place or removed from the tank, in some cases even when it is in operation. Thus, for example, during the rehabilitation of a tank, the cooling means may be wholly or partially removed, which facilitates access to the box and the maintenance work.

Dans certaines applications, il peut être avantageux d'assembler les moyens de refroidissement selon l'invention sous forme d'un dispositif de refroidissement en tout ou partie autonome. Un tel assemblage peut alors conduire à une conception globalisée et à une plus grande facilité d'opération. Le débit d'air général dudit dispositif peut être variable.In some applications, it may be advantageous to assemble the cooling means according to the invention in the form of a cooling device in whole or in part autonomous. Such an assembly can then lead to a globalized design and greater ease of operation. The general air flow rate of said device may be variable.

Selon le mode de réalisation préféré de l'invention, les moyens de refroidissement comprennent des moyens de répartition d'air, pour répartir le flux d'air autour du caisson, un moyen de refoulement d'air, qui permet de refouler l'air dans les moyens de répartition d'air, et des moyens de soufflage localisé, qui permettent de projeter l'air localement sous forme de jets, lesdites moyens de soufflage localisé étant disposés à des endroits déterminés du caisson. Les moyens de répartition comprennent de préférence des moyens de canalisation, tels que des conduites. Les moyens de soufflage localisé peuvent être des ajutages, des éjecteurs, des trompes, des buses ou des tuyaux. Les moyens de soufflage localisé sont avantageusement répartis le long des moyens de canalisation. Le débit d'air du moyen de refoulement peut être variable. Le débit d'air d'un ou de plusieurs des moyens de soufflage localisé peut aussi être variable individuellement.According to the preferred embodiment of the invention, the cooling means comprise air distribution means, for distributing the flow of air around the box, a means of air discharge, which allows the air to be forced back into the air distribution means, and localized blowing means, which project air locally in the form of jets, said localized blowing means being arranged at specific locations of the box. The distribution means preferably comprise channeling means, such as pipes. The localized blowing means may be nozzles, ejectors, horns, nozzles or pipes. The localized blowing means are advantageously distributed along the channeling means. The air flow of the discharge means may be variable. The air flow of one or more localized blowing means may also be individually variable.

L'usine de production d'aluminium par le procédé d'électrolyse Hall-Héroult selon le deuxième objet de l'invention est caractérisée en ce qu'elle comprend des cuves selon le premier objet de l'invention. Les cuves peuvent être équipées individuellement des moyens de refroidissement selon l'invention.The aluminum production plant by the Hall-Héroult electrolysis method according to the second subject of the invention is characterized in that it comprises tanks according to the first subject of the invention. The tanks can be individually equipped with cooling means according to the invention.

Les cuves peuvent être équipées individuellement du dispositif de refroidissement selon l'invention, qui peut, éventuellement, être contrôlé de manière centralisée.The tanks can be individually equipped with the cooling device according to the invention, which can optionally be controlled centrally.

En général, dans les usines d'électrolyse, les cuves d'électrolyse sont regroupées ou disposées en séries. Dans ces cas, les cuves peuvent avantageusement être équipées de moyens de refroidissement selon l'invention, qui sont, en tout ou partie, communs à deux ou plusieurs cuves, c'est-à-dire que deux ou plusieurs cuves ont en commun l'un desdits moyens de refroidissement. En particulier, il est dans certains cas avantageux de faire en sorte qu'un moyen de refoulement soit commun à deux ou plusieurs cuves.In general, in the electrolysis plants, the electrolysis cells are grouped or arranged in series. In these cases, the tanks may advantageously be equipped with cooling means according to the invention, which are wholly or partly common to two or more tanks, that is to say that two or more tanks have in common the one of said cooling means. In particular, it is in some cases advantageous to ensure that a discharge means is common to two or more tanks.

Description des figuresDescription of figures

  • La figure 1 illustre, de manière schématisée et en coupe transversale, une cuve d'électrolyse comprenant des moyens de refroidissement, assemblés sous forme d'un dispositif de refroidissement, selon un mode de réalisation préféré de l'invention.The figure 1 illustrates, schematically and in cross section, an electrolysis tank comprising cooling means, assembled in the form of a cooling device, according to a preferred embodiment of the invention.
  • La figure 2 illustre, de manière schématisée, en vue de côté, une cuve d'électrolyse selon le mode de réalisation de l'invention de la figure 1.The figure 2 illustrates, schematically, in side view, an electrolysis cell according to the embodiment of the invention of the figure 1 .
  • La figure 3 illustre, de manière schématisée, vue du dessous, une cuve d'électrolyse selon le mode de réalisation de l'invention de la figure 1.The figure 3 illustrates, schematically, seen from below, an electrolytic cell according to the embodiment of the invention of the figure 1 .
  • La figure 4 illustre, de manière non limitative, des variantes de l'invention selon lesquelles les moyens de canalisation ceinturent la cuve d'électrolyse en tout (b) ou partie (a).The figure 4 illustrates, in a nonlimiting manner, variants of the invention according to which the channeling means surround the electrolytic cell in all (b) or part (a).
  • Les figures 5 et 6 illustrent, de manière non limitative, des variantes de l'invention selon lesquelles un même moyen de refoulement est commun à plus d'une cuve.The figures 5 and 6 illustrate, without limitation, variants of the invention according to which the same discharge means is common to more than one tank.
Description détaillée de l'inventionDetailed description of the invention

La cuve d'électrolyse (1) pour la production d'aluminium par le procédé d'électrolyse Hall-Héroult selon l'invention comprend un caisson (2) en acier, des éléments de revêtement intérieur (3) et un ensemble cathodique (4), et des moyens de refroidissement par soufflage d'air à jets localisés répartis autour du caisson (2).The electrolysis cell (1) for the production of aluminum by the Hall-Heroult electrolysis method according to the invention comprises a box (2) made of steel, internal coating elements (3) and a cathode assembly (4). ), and local jet air cooling means distributed around the housing (2).

Les éléments de revêtement intérieur (3) sont généralement des blocs en matériaux réfractaires, qui peuvent être des isolants thermiques. L'ensemble cathodique (4) comprend des barres de raccordement (9) auxquelles sont fixés les conducteurs électriques servant à l'acheminement du courant d'électrolyse. Les éléments de revêtement et l'ensemble cathodique forment un creuset à l'intérieur de la cuve, lequel creuset permet de contenir le bain d'électrolyte (7) et la nappe de métal liquide (6) lorsque la cuve est en charge. Les anodes (11) sont partiellement immergées dans le bain d'électrolyte (7). Le bain d'électrolyte contient de l'alumine dissoute et, en général, une couverture d'alumine (8) recouvre le bain d'électrolyte.The lining elements (3) are generally blocks of refractory materials, which may be thermal insulators. The cathode assembly (4) comprises connecting bars (9) to which are fixed the electrical conductors for the routing of the electrolysis current. The coating elements and the cathode assembly form a crucible inside the tank, which crucible makes it possible to contain the electrolyte bath (7) and the sheet of liquid metal (6) when the tank is in charge. The anodes (11) are partially immersed in the electrolyte bath (7). The electrolyte bath contains dissolved alumina and, in general, a blanket of alumina (8) covers the electrolyte bath.

L'aluminium métal (6) qui est produit au cours de l'électrolyse s'accumule au fond de la cuve, de sorte qu'il s'établit une interface assez nette entre le métal liquide (6) et le bain de cryolithe fondue (7). La position de cette interface bain-métal varie au cours du temps : elle s'élève au fur et à mesure que le métal liquide s'accumule au fond de la cuve et elle s'abaisse lorsque du métal liquide est extrait de la cuve.The aluminum metal (6) produced during the electrolysis accumulates at the bottom of the tank, so that there is a fairly clear interface between the molten metal (6) and the molten cryolite bath (7). The position of this bath-metal interface varies over time: it rises as the liquid metal accumulates at the bottom of the tank and lowers when liquid metal is removed from the tank.

La conduite des cuves d'électrolyse s'effectue en général par le contrôle de plusieurs paramètres, tels que la concentration en alumine de l'électrolyte, la température du bain d'électrolyte, la hauteur totale du bain ou la position des anodes. En règle générale, on cherche à former un talus (5) de cryolithe solidifiée sur la partie des parois latérales (12) du creuset qui sont en contact avec le bain d'électrolyte (7) et avec la nappe de métal liquide (6). Lesdites parois sont souvent constituées de dalles de bordure en matériau carboné ou à base de composés carbonés, tels qu'un réfractaire à base de SiC, et de pâtes de brasque. Afin d'augmenter l'efficacité des moyens de refroidissement selon l'invention, les parois latérales peuvent comprendre des blocs ou côtés préformés, de préférence homogènes, constitués d'un matériau de conductivité thermique élevée, au moins plus élevée que celle des pâtes de brasques, et de préférence encore au moins égale à celle des dalles de bordures normalement utilisées, tel que par exemple un matériau à base de SiC.The conduct of the electrolysis cells is generally carried out by the control of several parameters, such as the concentration of alumina of the electrolyte, the temperature of the electrolyte bath, the total height of the bath or the position of the anodes. As a rule, it is sought to form a solidified cryolite bank (5) on the part of the side walls (12) of the crucible which are in contact with the electrolyte bath (7) and with the sheet of liquid metal (6) . Said walls are often made of edge slabs made of carbonaceous material or based on carbon compounds, such as an SiC-based refractory, and broth pasta. In order to increase the efficiency of the cooling means according to the invention, the side walls may comprise preformed blocks or sides, preferably homogeneous, made of a material of high thermal conductivity, at least higher than that of the pasta doughs. and more preferably at least equal to that of the curb slabs normally used, such as for example a material based on SiC.

De préférence, la cuve est aussi munie d'un dispositif de captage permettant de capter et de récupérer les effluents gazeux émis par le bain d'électrolyte au cours de l'électrolyse. Le dispositif de captage comprend sur l'ensemble de la cuve un capotage (10) généralement muni de capots et d'accès ouvrants.Preferably, the tank is also provided with a collection device for capturing and recovering the gaseous effluents emitted by the electrolyte bath during the electrolysis. The sensing device comprises on the entire vessel a cowling (10) generally provided with opening covers and access.

Selon un mode de réalisation préféré de l'invention, les moyens de refroidissement comprennent des moyens de canalisation (28), tels que des conduites (21-24), un moyen de refoulement (25) pour refouler de l'air dans lesdits moyens de canalisation, et des moyens de soufflage localisé (27) permettant de projeter l'air sous forme de jets localisés. Ces moyens forment de préférence un dispositif de refroidissement (20).According to a preferred embodiment of the invention, the cooling means comprise ducting means (28), such as ducts (21-24), discharge means (25) for discharging air into said means. pipe, and localized blowing means (27) for projecting the air in the form of localized jets. These means preferably form a cooling device (20).

Les moyens de canalisation (28) peuvent être maintenus en position par différents moyens. En particulier, ils peuvent être fixés aux éléments de structure ou de renfort de la cuve, tels que des raidisseurs, qui peuvent être modifiés ou adaptés à cette fin Les moyens de canalisation (28) peuvent aussi être adossés au caisson ou posés contre celui-ci, ou encore fixés au plat-bord du caisson.The channeling means (28) can be held in position by different means. In particular, they can be attached to the structural elements or reinforcement of the tank, such as stiffeners, which can be modified or adapted for this purpose The channeling means (28) can also be leaned against the caisson or placed against it ci, or fixed to the edge of the box.

Le débit d'air général du dispositif (20) peut avantageusement être variable, par exemple à l'aide de vannes ou par une variation du débit du moyen de refoulement (25). Le débit d'air d'un ou plusieurs des moyens de soufflage localisé peut aussi être variable, éventuellement de manière individuelle, avec éventuellement aussi la possibilité de réduire à zéro le flux de certains moyens de soufflage. L'air peut dans certains cas être pulsé.The general air flow rate of the device (20) can advantageously be variable, for example by means of valves or by a variation of the flow rate of the discharge means (25). The air flow of one or more localized blowing means may also be variable, possibly individually, with possibly also the possibility of reducing to zero the flow of certain blowing means. The air can in some cases be pulsed.

Les moyens de refroidissement, ou le dispositif de refroidissement, selon l'invention sont éventuellement en tout ou partie amovibles. En particulier, les conduites peuvent être aisément démontables et transportables, grâce notamment à une conception par tronçons et à des moyens d'assemblages appropriés.The cooling means, or the cooling device, according to the invention are optionally entirely or partially removable. In particular, the pipes can be easily dismountable and transportable, thanks in particular to a sectional design and to appropriate assembly means.

L'air refoulé dans les moyens de canalisation est soufflé sur les parois du caisson, à des endroits déterminés, à l'aide de moyens de soufflage localisé (27), qui sont avantageusement répartis le long des moyens de canalisation. Les moyens de soufflage localisé ne sont pas nécessairement répartis de manière uniforme sur la surface du caisson ; il peut quelquefois être préférable de les concentrer dans certaines zones particulières.The air discharged into the channeling means is blown on the walls of the box, at predetermined locations, by means of localized blowing means (27), which are advantageously distributed along the channeling means. The localized blowing means are not necessarily distributed uniformly over the surface of the box; it may sometimes be preferable to concentrate them in particular areas.

Les moyens de soufflage localisé (27) permettent de diriger le flux d'air à des endroits précis du caisson, par exemple à la hauteur du bain d'électrolyte (7). Il est avantageux qu'un ou plusieurs des moyens de soufflage localisé (27) soient orientables. Les moyens de soufflage localisé projettent l'air soufflé à une vitesse, appelée vitesse d'éjection, qui est de préférence entre 10 et 100 m/s, et de préférence encore entre 20 et 70 m/s.The localized blowing means (27) make it possible to direct the flow of air at precise locations in the box, for example at the height of the electrolyte bath (7). It is advantageous for one or more localized blowing means (27) to be orientable. The localized blowing means project the blown air at a speed, called the ejection speed, which is preferably between 10 and 100 m / s, and more preferably between 20 and 70 m / s.

Le nombre, la position et les dimensions des moyens de soufflage localisé (27), la puissance du moyen de refoulement (25), ainsi que la configuration et les dimensions des moyens de canalisation (21 à 24), sont choisis de façon à ce que le débit d'air soit suffisant pour permettre un refroidissement efficace et de façon à assurer une puissance de refroidissement déterminée au niveau des points de soufflage sélectionnés, en tenant compte notamment de l'aéraulique du réseau.The number, the position and the dimensions of the localized blowing means (27), the power of the delivery means (25), as well as the configuration and the dimensions of the channeling means (21 to 24) are chosen so that the air flow is sufficient to allow efficient cooling and to ensure a determined cooling power at the selected blowing points, taking into account in particular the network aeraulic.

Le moyen de refoulement de l'air (25) peut être un ventilateur, qui refoule de l'air ambiant, ou une soufflerie à air comprimé, tel qu'un ventilo-trompe, ou un système à air comprimé détendu ou une réseau d'air surpressé.The air discharge means (25) may be a fan, which delivers from the ambient air, or a compressed air blower, such as a fan-trunk, or a compressed air system or a compressed air system. air overheated.

Pour des raisons de sécurité électrique, il est quelquefois préférable d'isoler électriquement le moyen de refoulement (25) du reste du dispositif à l'aide d'un moyen d'isolement électrique (26), tel qu'une section de conduite en matériau isolant électrique.For reasons of electrical safety, it is sometimes preferable to electrically insulate the discharge means (25) from the rest of the device by means of an electrical isolation means (26), such as a conducting section. electrical insulating material.

Les conduites (21-24) peuvent être constituées de matériaux métalliques, de préférence amagnétiques (tels que de l'acier inoxydable amagnétiques ou de l'aluminium), ou de matériaux isolants (tels que les fibres de verre), ou une combinaison de ceux-ci (telle qu'un conduit métallique muni d'une gaine isolante).The pipes (21-24) may be made of metal materials, preferably non-magnetic (such as non-magnetic stainless steel or aluminum), or insulating materials (such as glass fibers), or a combination of these (such as a metal duct provided with an insulating sheath).

Le dispositif de refroidissement (20) peut éventuellement être contrôlé par le système de régulation général de la cuve, de manière à assurer une régulation globale centralisée plus efficace.The cooling device (20) can optionally be controlled by the general control system of the tank, so as to ensure a more efficient centralized overall control.

La cuve peut aussi être munie des moyens de refroidissement complémentaires, notamment des moyens de refroidissement statiques, tels que des ailettes ou des moyens équivalents. De manière à augmenter l'efficacité globale des moyens (ou du dispositif) de refroidissement, il est avantageux, dans certains cas et/ou en certains endroits de la cuve, de combiner l'effet des moyens de soufflage à celui des moyens complémentaires.The tank may also be provided with complementary cooling means, in particular static cooling means, such as fins or equivalent means. In order to increase the overall efficiency of the cooling means (or device), it is advantageous, in certain cases and / or in certain parts of the tank, to combine the effect of the blowing means with that of the complementary means.

Selon une variante de l'invention, illustrée par exemple aux figures 1 à 3, les moyens de canalisation forment des rameaux, c'est-à-dire qu'ils sont constitués de telle manière qu'un moyen de canalisation principal (21) se ramifie en branches horizontales sous la cuve (22), verticales sur les côtés et les têtes de cuve (23) et horizontales sur les côtés et les têtes de cuve (24). Cette configuration assure un équilibrage aéraulique satisfaisant du réseau de conduites et facilite la mise en place du dispositif de refroidissement. En particulier, les branches verticales peuvent être placées entre les barres cathodiques (9).According to a variant of the invention, illustrated for example in Figures 1 to 3 , the channeling means form shoots, that is to say they are constituted such that a main channeling means (21) branched in horizontal branches under the tank (22), vertical on the sides and the tank heads (23) and horizontal on the sides and the tank heads (24). This configuration ensures a satisfactory aeraulic balancing of the pipe network and facilitates the installation of the cooling device. In particular, the vertical branches can be placed between the cathode bars (9).

Selon une autre variante de l'invention, illustrée par exemple à la figure 4, les moyens de canalisation (28) entourent ou ceinturent en tout ou partie le caisson (2) de la cuve d'électrolyse.According to another variant of the invention, illustrated for example in figure 4 , the channeling means (28) surround or wholly or partially surround the box (2) of the electrolytic cell.

Selon les variantes de l'invention illustrées aux figures 5 et 6, un unique moyen de refoulement (25) est commun à plus d'une cuve, et plus précisément à deux ou plusieurs cuves d'une usine. Le moyen de refoulement (25) répartit le flux d'air par l'intermédiaire d'un réseau (29) comprenant un conduit principal commun (30) et un point de raccordement (31) pour chaque cuve. Les points de raccordement sont éventuellement munis de vannes pour isoler chaque cuve individuellement et de mises à l'air pour rééquilibrer la répartition des flux d'air. Les vannes et les mises à l'air sont notamment utiles lors d'interventions sur une cuve particulière ou sur certaines d'entre elles puisqu'elles permettent d'isoler la ou les cuves concernées tout en préservant des débits d'air satisfaisant pour les autres cuves raccordées au réseau.According to the variants of the invention illustrated in figures 5 and 6 , a single discharge means (25) is common to more than one tank, and more specifically to two or more tanks of a plant. The delivery means (25) distributes the airflow through a network (29) comprising a common main duct (30) and a connection point (31) for each tank. The connection points are optionally equipped with valves to isolate each tank individually and venting to rebalance the distribution of air flows. Valves and venting are particularly useful during interventions on a particular tank or on some of them since they allow to isolate the tank or tanks concerned while preserving satisfactory air flow rates for them. other tanks connected to the network.

Dans une usine, les moyens de refroidissements sont avantageusement contrôlés ou pilotés à l'aide d'un système de régulation commun à plus d'une cuve. Typiquement, chaque cuve munie de moyens de refroidissement propres ou chaque groupe de cuves munies de moyens de refroidissement ayant des éléments en commun (notamment le moyen de refoulement) peut être piloté par un système de régulation dit de premier niveau, et l'ensemble des cuves ou des groupes de cuves d'un hall d'électrolyse particulier de l'usine peut, en outre, être piloté de manière globale par un système de régulation dit de deuxième niveau.In a factory, the cooling means are advantageously controlled or controlled by means of a control system common to more than one tank. Typically, each tank provided with own cooling means or each group of tanks provided with cooling means having elements in common (in particular the discharge means) can be controlled by a so-called first level control system, and all Vats or groups of vats of a particular electrolysis hall of the plant can, moreover, be controlled globally by a so-called second-level control system.

ExempleExample

Des essais sur des cuves d'électrolyse de 300 kA ont été réalisés avec un dispositif de refroidissement conforme à l'invention ayant les caractéristiques spécifiques suivantes.Tests on 300 kA electrolytic cells were carried out with a cooling device according to the invention having the following specific characteristics.

En référence aux figures 1 à 3, une conduite principale (21) passe longitudinalement sous le caisson (2) jusque près du centre de la cuve, puis se divise en trois branches (22a, 22b, 22c) perpendiculaires l'une à l'autre et de section plus faible que la conduite principale ; une branche longitudinale (22a) s'étend sous le caisson jusqu'à l'autre extrémité de celle-ci, puis forme une branche verticale (23a), qui remonte le long de la tête de cuve jusqu'à la hauteur de la dalle de bordure, approximativement, puis bifurque en deux rameaux horizontaux (24a, 24a') qui s'étendent jusque vers les bords latéraux de la cuve ; les deux autres branches (22b, 22c), transversales, s'étendent jusque vers les côtés latéraux du caisson, puis forment des branches verticales (23b, 23c) qui remontent le long de celui-ci jusqu'à la hauteur de la dalle de bordure, approximativement puis bifurquent en deux rameaux horizontaux (24b, 24b', 24c, 24c'), de chaque côté de la cuve, qui s'étendent jusque vers les têtes de la cuve. Une branche verticale (23c) équivalente à la branche (23a) est raccordée directement à la conduite principale, et se ramifie également en deux rameaux horizontaux (24c, 24c').With reference to Figures 1 to 3 , a main pipe (21) passes longitudinally under the box (2) to near the center of the tank, then divides into three branches (22a, 22b, 22c) perpendicular to each other and of smaller section than the main pipe; a longitudinal branch (22a) extends under the box to the other end thereof, then forms a vertical branch (23a), which goes up along the tank head to the height of the slab border, approximately, then branches in two horizontal branches (24a, 24a ') which extend to the side edges of the tank; the other two branches (22b, 22c), transverse, extend to the lateral sides of the box, then form vertical branches (23b, 23c) which go up along it to the height of the slab of border, approximately then bifurcate in two horizontal branches (24b, 24b ', 24c, 24c'), on each side of the tank, which extend to the heads of the tank. A vertical branch (23c) equivalent to the branch (23a) is connected directly to the main pipe, and also branched into two horizontal branches (24c, 24c ').

Des buses (27) ont été disposées uniformément le long des rameaux. Selon les essais, le nombre des buses était de 5 à 8 buses le long de chaque tête de cuve et de 15 à 20 buses sur chaque côté de cuve. Les buses étaient dirigées approximativement en direction du niveau bain-métal théorique dans la plupart des essais. Dans certains essais, certaines buses ont été dirigées vers des éléments de renforcement structural du caisson, qui ont ainsi servi d'ailettes de refroidissement. Les conduites et les buses étaient en acier, et en partie en acier inoxydable.Nozzles (27) have been arranged uniformly along the branches. According to the tests, the number of nozzles was 5 to 8 nozzles along each head of the tank and 15 to 20 nozzles on each tank side. The nozzles were directed approximately to the theoretical bath-metal level in most tests. In some tests, some nozzles were directed to structural reinforcement elements of the box, which served as cooling fins. The pipes and nozzles were made of steel, and partly of stainless steel.

Le moyen de refoulement d'air (25) était, dans certains essais, un ventilateur mécanique et, dans d'autres essais, un ventilo-trompe. Les dispositifs de refroidissement étaient munis de moyens permettant de varier le débit d'air.The air discharge means (25) was, in some tests, a mechanical fan and, in other tests, a fan-horn. The cooling devices were provided with means for varying the air flow.

Les essais ont montré que le dispositif de refroidissement restait efficace pour des vitesses d'éjection de l'air à la sortie des buses se situant entre environ 10 m/s et environ 100 m/s. L'efficacité du dispositif diminuait fortement, jusqu'à devenir sans effet significatif, lorsque les vitesses étaient inférieures à 10 m/s. Les vitesses supérieures à 100 m/s conduisaient à des pertes de charge très importantes, qui auraient nécessité des moyens de refoulement de puissance et/ou de coût rédhibitoires. Les meilleurs résultats ont été obtenus avec des vitesses d'éjection comprises entre 20 et 70 m/s.The tests have shown that the cooling device remains effective for air ejection velocities at the outlet of the nozzles ranging between about 10 m / s and about 100 m / s. The effectiveness of the device decreased sharply, until it became without significant effect, when speeds were less than 10 m / s. Speeds higher than 100 m / s led to very large pressure losses, which would have required power repression means and / or cost prohibitive. The best results have been obtained with ejection speeds of between 20 and 70 m / s.

Les mesures de température, à l'aide de thermocouples et de pyromètres, ont montré que le dispositif permettait d'obtenir des abaissements de température moyenne de 50 à 100 °C à la hauteur des parois latérales. La régulation du refroidissement a facilement été obtenue par une variation du débit d'air refoulé.Temperature measurements, using thermocouples and pyrometers, showed that the device made it possible to obtain average temperature decreases of 50 to 100 ° C at the height of the side walls. Cooling control was easily achieved by varying the amount of discharge air.

La demanderesse a ainsi constaté que, de façon surprenante, il était possible d'atteindre des taux de refroidissement satisfaisants par soufflage d'air selon l'invention, sans avoir recours à des moyens de refoulement et de soufflage ou à des conduites démesurés, ou disproportionnés, et/ou qui nécessitent des investissements et/ou des coûts de fonctionnement trop importants, voire rédhibitoires.The Applicant has thus found that, surprisingly, it was possible to achieve satisfactory cooling rates by blowing air according to the invention, without having recourse to the means of discharge and blowing or excessive conduct, or disproportionate, and / or which require investments and / or operating costs that are too high or even prohibitive.

Ces essais ont également montré que l'air projeté sur les parois de la cuve, et qui s'est réchauffé à son contact, se dilue assez rapidement dans l'air environnant et ne conduit pas à une élévation significative de la température de l'air ambiant. En d'autres termes, les essais n'ont pas mis en évidence des valeurs de température ambiante qui s'écartent de manière significative des valeurs habituellement observées au voisinage des cuves de l'art antérieur, même lorsque la température ambiante atteint des valeurs extrêmes en été.These tests have also shown that the air projected on the walls of the tank, which has warmed up on contact with it, dilutes rather rapidly in the surrounding air and does not lead to a significant rise in the temperature of the tank. ambiant air. In other words, the tests did not reveal ambient temperature values which differ significantly from the values usually observed in the vicinity of the tanks of the prior art, even when the ambient temperature reaches extreme values. in summer.

On a également constaté que, de manière surprenante, le niveau sonore du dispositif était particulièrement faible.It has also been found that, surprisingly, the sound level of the device was particularly low.

Avantages de l'inventionAdvantages of the invention

Selon l'invention, les moyens de refroidissement permettent d'évacuer et de dissiper l'énergie thermique produite dans la cuve d'électrolyse, par un contrôle optimal de certains flux thermiques, qui peut être adapté à différentes conditions climatiques et/ou de fonctionnement de la cuve, lesquelles peuvent s'éloigner de manière significative des conditions nominales ou standard. Les moyens de refroidissement permettent en outre de maîtriser, avec précision, la formation du talus de bain de cryolithe solidifiée.According to the invention, the cooling means make it possible to evacuate and dissipate the heat energy produced in the electrolytic cell, by an optimal control of certain thermal flows, which can be adapted to different climatic and / or operating conditions of the tank, which can significantly deviate from nominal conditions or standard. The cooling means furthermore make it possible to control, with precision, the formation of the solidified cryolite bath slope.

Les moyens de refroidissement, ou le dispositif de refroidissement, selon l'invention s'adaptent aisément à tout type de cuve et à différents environnements. Ils peuvent facilement être mis en place sur des cuves existantes, notamment dans le cadre de leur remise à neuf, de l'intégration d'une régulation thermique et/ou d'une modification de l'intensité nominale. Plus spécifiquement, l'invention facilite les modulations de la puissance des cuves qui permettent de tenir compte, par exemple, des contraintes techniques, économiques et/ou contractuelles. En particulier, l'invention permet une augmentation de l'intensité nominale de cuves existantes, sans entraîner de dégradation prématurée des cuves.The cooling means or the cooling device according to the invention can easily be adapted to any type of tank and to different environments. They can easily be installed on existing tanks, especially in the context of their refurbishment, the integration of a thermal regulation and / or a change in the nominal intensity. More specifically, the invention facilitates modulations of the power of the tanks which allow to take into account, for example, technical, economic and / or contractual constraints. In particular, the invention allows an increase in the nominal intensity of existing tanks, without causing premature degradation of the tanks.

Dans une usine d'électrolyse selon l'invention, la possibilité d'adapter cuve à cuve les moyens, ou le dispositif, de refroidissement, ainsi que ses conditions de fonctionnement, permet l'optimisation de la conduite de plusieurs cuves à la fois, voire d'une série complète de cuves, de manière notamment à uniformiser le point de fonctionnement des cuves. En particulier, l'invention permet un contrôle thermique individualisé des cuves d'une usine, ce qui s'avère souvent nécessaire dans les usines à grande productivité. C'est le cas, par exemple, lors des phases transitoires qui surviennent lorsque certaines cuves d'une même série ont des brasquages neufs ou différents de ceux du reste de la série.In an electrolysis plant according to the invention, the possibility of adapting the tank to the means, or the cooling device, as well as its operating conditions, makes it possible to optimize the driving of several tanks at a time, even a complete series of tanks, so in particular to standardize the point of operation of the tanks. In particular, the invention allows an individualized thermal control of the vats of a plant, which is often necessary in factories with high productivity. This is the case, for example, during the transient phases that occur when certain vats of the same series have new or different solders from those of the rest of the series.

L'invention permet aussi la modernisation d'usines existantes sans nécessiter des travaux d'infrastructure qui rendraient rédhibitoires de telles opérations.The invention also allows the modernization of existing plants without the need for infrastructure work that would make such operations prohibitive.

L'invention permet également de prolonger la vie d'une cuve en fin de vie, dont le caisson présente des points chauds anormaux.The invention also makes it possible to prolong the life of a tank at the end of its life, whose casing has abnormal hot spots.

Claims (17)

  1. Electrolytic cell for the production of Aluminium by the Hall-Héroult electrolysis process, comprising a steel pot shell, internal lining elements and a cathode assembly, the said cell being characterised in that it comprises air blast cooling means with localized jets distributed around the said pot shell, so as to fix these preferential cooling zones on the surface of the shell, these zones being determined according to the thermal profile of the cell, with the aim of increasing the overall effectiveness of cooling so as to control the heat flows of the cell, in that said air blast cooling means are assembled in the form of a cooling device, in that said cooling means include air distribution means, to distribute the flow of air around the shell, a blowing means for blowing air in the said distribution means and localized blast means for directing air in the form of localized jets, said localized air blast means being laid out at given places on the shell, in that said means of distribution include means of conveyance, in that said means of conveyance partly or fully surround or encircle said shell, in that the localized air blast means are distributed along said means of conveyance according to a determined distribution including a plurality of jets on each side of the cell, and in that the blowing means are chosen from the group made up of fans, expanded compressed-air systems and pressurized air networks.
  2. Cell according to claim 1, characterised in that the airflow through the said air blast cooling means is variable.
  3. Cell according to either of claims 1 or 2, characterised in that the said air blast cooling means are controlled by the regulation system of the said cell.
  4. Cell according to one of claims 1 to 3, characterised in that said air blast cooling means are all or partly removable.
  5. Cell according to one of claims 1 to 4, characterised in that the airflow through one or more of the localized air blast means is variable.
  6. Cell according to one of claims 1 to 5, characterised in that one or more localised air blast means can be oriented.
  7. Cell according to one of claims 1 to 6, characterised in that the localized air blast means are chosen from the group consisting of orifices, ejectors, ejector outlets, nozzles and pipes.
  8. Cell according to one of claims 1 to 7, characterised in that the localized air blast means direct blown air at a velocity of between 10 and 100 m/s, and preferably between 20 and 70 m/s
  9. Cell according to one of claims 1 to 8, characterised in that the air flow from the blowing means is variable.
  10. Cell according to one of claims 1 to 9, characterised in that the said conveyance means form branches.
  11. Cell according to one of claims 1 to 10, characterised in that the sidewalls of the crucible formed inside the said cell by said lining elements and the cathode assembly comprise preformed blocks.
  12. Aluminium production plant using the Hall-Héroult electrolysis process, characterised in that it comprises cells according to one of claims 1 to 11.
  13. Plant according to claim 12 characterised in that one or more cells have one of said cooling means in common.
  14. Aluminium production plant using the Hall-Héroult electrolysis process, characterised in that it comprises cells according to one of claims 1 to 11, and in that two or more cells have the said blowing means in common.
  15. Plant according to claim 14, characterised in that the said common blowing means distribute the airflow through a network comprising a common main pipe and a connection point for each of the said cells.
  16. Plant according to claim 15, characterised in that each connection point is provided with at least one valve to isolate the cell associated with the connection point and at least one vent to rebalance the distribution of airflows.
  17. Plant according to claims 12 to 16, characterised in that said means of cooling are controlled by a regulation system common to two or more cells.
EP99911893A 1998-04-16 1999-04-07 Fused bath electrolysis cell for producing aluminium by hall-heroult process comprising cooling means Expired - Lifetime EP1070158B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
SI9930491T SI1070158T2 (en) 1998-04-16 1999-04-07 Fused bath electrolysis cell for producing aluminium by hall-heroult process comprising cooling means

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9805040 1998-04-16
FR9805040A FR2777574B1 (en) 1998-04-16 1998-04-16 IGNITED ELECTROLYSIS TANK FOR THE PRODUCTION OF ALUMINUM BY THE HALL-HEROULT PROCESS INCLUDING COOLING MEANS
PCT/FR1999/000802 WO1999054526A1 (en) 1998-04-16 1999-04-07 Fused bath electrolysis cell for producing aluminium by hall-heroult process comprising cooling means

Publications (3)

Publication Number Publication Date
EP1070158A1 EP1070158A1 (en) 2001-01-24
EP1070158B1 EP1070158B1 (en) 2003-10-01
EP1070158B2 true EP1070158B2 (en) 2009-08-05

Family

ID=9525541

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99911893A Expired - Lifetime EP1070158B2 (en) 1998-04-16 1999-04-07 Fused bath electrolysis cell for producing aluminium by hall-heroult process comprising cooling means

Country Status (18)

Country Link
US (1) US6251237B1 (en)
EP (1) EP1070158B2 (en)
AR (1) AR026090A1 (en)
AU (1) AU746349B2 (en)
BR (1) BR9909613B1 (en)
CA (1) CA2328768C (en)
DE (1) DE69911758T2 (en)
EG (1) EG21924A (en)
ES (1) ES2209412T5 (en)
FR (1) FR2777574B1 (en)
GC (1) GC0000048A (en)
IS (1) IS2692B (en)
NO (1) NO328847B1 (en)
RU (1) RU2201476C2 (en)
SI (1) SI1070158T2 (en)
SK (1) SK285426B6 (en)
WO (1) WO1999054526A1 (en)
ZA (1) ZA200005405B (en)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO313462B1 (en) * 2000-06-07 2002-10-07 Elkem Materials Electrolytic cell for the production of aluminum, a series of electrolytic cells in an electrolysis hall, a method for maintaining a crust on a sidewall of an electrolytic cell, and a method for recovering electrical energy from an electr.
US6839305B2 (en) * 2001-02-16 2005-01-04 Neil Perlman Habit cessation aide
US6855241B2 (en) 2002-04-22 2005-02-15 Forrest M. Palmer Process and apparatus for smelting aluminum
FR2842215B1 (en) * 2002-07-09 2004-08-13 Pechiney Aluminium METHOD AND SYSTEM FOR COOLING AN ELECTROLYSIS TANK FOR THE PRODUCTION OF ALUMINUM
US8247556B2 (en) * 2005-10-21 2012-08-21 Amgen Inc. Method for preparing 6-substituted-7-aza-indoles
FR2893329B1 (en) * 2005-11-14 2008-05-16 Aluminium Pechiney Soc Par Act ELECTROLYSIS TANK WITH THERMAL EXCHANGER.
WO2008014042A1 (en) * 2006-07-24 2008-01-31 Alcoa Inc. Electrolysis cells for the production of metals from melts comprising sidewall temperature control systems
CN101376991B (en) * 2007-08-31 2011-08-31 沈阳铝镁设计研究院有限公司 Forced cooling system for aluminum cell
EP2271582A4 (en) * 2008-04-02 2014-01-22 Cedar Ridge Research Llc Aluminum-alkali hydroxide recyclable hydrogen generator
EP2431498B1 (en) 2010-09-17 2016-12-28 General Electric Technology GmbH Pot heat exchanger
FR2976593B1 (en) 2011-06-16 2014-09-05 Rio Tinto Alcan Int Ltd ELECTROLYSIS TANK FOR USE IN PRODUCING ALUMINUM
US9347708B2 (en) 2011-09-29 2016-05-24 Hatch Ltd. Furnace with refractory bricks that define cooling channels for gaseous media
CN104562086B (en) * 2015-02-03 2017-09-19 奉新赣锋锂业有限公司 A kind of temperature-adjustable metal lithium electrolytic bath
EP3266904B1 (en) 2016-07-05 2021-03-24 TRIMET Aluminium SE Molten salt electrolysis system and control method for operation of the same
GB2564456A (en) * 2017-07-12 2019-01-16 Dubai Aluminium Pjsc Electrolysis cell for Hall-Héroult process, with cooling pipes for forced air cooling
AU2017433177A1 (en) 2017-09-29 2020-03-19 Bechtel Mining & Metals, Inc. Systems and methods for controlling heat loss from an electrolytic cell
CN110205649A (en) * 2019-05-17 2019-09-06 中国铝业股份有限公司 A kind of efficient aluminum cell shell Local cooling method of solar term
CN113432439B (en) * 2021-07-29 2022-09-06 东北大学 Cooling method for aluminum electrolysis cell after stopping operation

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO135033C (en) * 1975-04-10 1977-01-26 Norsk Hydro As
US4087345A (en) * 1977-07-19 1978-05-02 Ardal Og Sunndal Verk A.S. Potshell for electrolytic aluminum reduction cell
SU633937A1 (en) * 1977-07-20 1978-11-25 Северо-Западное Отделение Всесоюзного Государственного Научноисследовательского И Проектноконструкторского Института "Внипиэнергопром" Aluminium electrolyzer
FR2441313A1 (en) * 1978-11-10 1980-06-06 Siderurgie Fse Inst Rech COOLED ELECTRODE FOR CONTACT WITH FUSED METAL
CH651856A5 (en) * 1981-07-14 1985-10-15 Alusuisse MELT FLOW ELECTROLYSIS CELL FOR THE PRODUCTION OF ALUMINUM AND HALL EQUIPPED WITH IT.
US4451337A (en) * 1983-06-30 1984-05-29 Eyvind Frilund Heat recovery in aluminium-melting works
US4608134A (en) * 1985-04-22 1986-08-26 Aluminum Company Of America Hall cell with inert liner
US4608135A (en) * 1985-04-22 1986-08-26 Aluminum Company Of America Hall cell
NO158511C (en) * 1985-07-09 1988-09-21 Invendt A S H OVEN L DEVICE, SPECIAL LUMINIUM ELECTROLYSE.
RU2058432C1 (en) * 1994-06-17 1996-04-20 Российский научно-исследовательский и проектный институт титана и магния Electrolyzer for producing manganese and chlorine

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
H. KVANDE: "Common cathode failures and remedies.", 8TH INTERNATIONAL LIGHTMETAL CONGRESS, 22 June 1987 (1987-06-22) - 26 June 1987 (1987-06-26), LEOBEN/VIENNA, AUSTRIA, pages 160 - 162 †

Also Published As

Publication number Publication date
EP1070158A1 (en) 2001-01-24
IS5655A (en) 2000-10-11
NO20005174L (en) 2000-11-30
DE69911758D1 (en) 2003-11-06
AU3041999A (en) 1999-11-08
FR2777574B1 (en) 2000-05-19
CA2328768A1 (en) 1999-10-28
AR026090A1 (en) 2003-01-29
AU746349B2 (en) 2002-04-18
SI1070158T2 (en) 2009-10-31
BR9909613A (en) 2000-12-12
BR9909613B1 (en) 2010-07-13
FR2777574A1 (en) 1999-10-22
EP1070158B1 (en) 2003-10-01
WO1999054526A1 (en) 1999-10-28
GC0000048A (en) 2004-06-30
ZA200005405B (en) 2001-08-29
DE69911758T2 (en) 2004-07-29
SK15332000A3 (en) 2001-05-10
US6251237B1 (en) 2001-06-26
NO328847B1 (en) 2010-05-31
ES2209412T5 (en) 2009-11-06
EG21924A (en) 2002-04-30
NO20005174D0 (en) 2000-10-13
IS2692B (en) 2010-11-15
SK285426B6 (en) 2007-01-04
SI1070158T1 (en) 2004-04-30
RU2201476C2 (en) 2003-03-27
ES2209412T3 (en) 2004-06-16
CA2328768C (en) 2005-10-11

Similar Documents

Publication Publication Date Title
EP1070158B2 (en) Fused bath electrolysis cell for producing aluminium by hall-heroult process comprising cooling means
EP1527213B1 (en) Method and system for cooling an electrolytic cell for aluminium production
US20070187230A1 (en) Internal Cooling of Electrolytic Smelting Cell
CA2627956A1 (en) Electrolytic cell with a heat exchanger
CN105229206A (en) Directional solidification system and method
CA2411453C (en) Electrolytic cell for the production of aluminium and a method for maintaining a crust on a sidewall and for recovering electricity
WO2009066025A2 (en) Grooved anode for an electrolysis tank
FR2712217A1 (en) Pocket for processing liquid metal with a small footprint and improved performance.
US20100132906A1 (en) Method of casting a metal article
WO2012020188A1 (en) Method and device for confining cell gases in an aluminium electrolysis cell
EP1155167B1 (en) Electrolytic cell arrangement for production of aluminium
RU2321682C2 (en) Cathode device of aluminum cell
KR101397979B1 (en) Apparatus for Refining Silicon
KR101483695B1 (en) Apparatus for Refining Silicon
WO2023087107A1 (en) Interior lining system for an electrolytic cell
KR101475755B1 (en) Apparatus for Refining Silicon
KR101401347B1 (en) Apparatus for Refining Silicon
KR20140027626A (en) Apparatus for refining silicon
FR2606549A1 (en) Evacuating TV CRT or electrical discharge tube
FR3016892A1 (en) DEVICE FOR PREHEATING AN ANODE ASSEMBLY.
AU2005306566A1 (en) Internal cooling of electrolytic smelting cell

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20001024

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE ES FR GB GR NL

AX Request for extension of the european patent

Free format text: RO PAYMENT 20001024;SI PAYMENT 20001024

17Q First examination report despatched

Effective date: 20010131

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB GR NL

AX Request for extension of the european patent

Extension state: RO SI

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REF Corresponds to:

Ref document number: 69911758

Country of ref document: DE

Date of ref document: 20031106

Kind code of ref document: P

REG Reference to a national code

Ref country code: GR

Ref legal event code: EP

Ref document number: 20030405098

Country of ref document: GR

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20040115

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2209412

Country of ref document: ES

Kind code of ref document: T3

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBQ Unpublished change to opponent data

Free format text: ORIGINAL CODE: EPIDOS OPPO

26 Opposition filed

Opponent name: NORSK HYDRO ASA

Effective date: 20040624

PLAX Notice of opposition and request to file observation + time limit sent

Free format text: ORIGINAL CODE: EPIDOSNOBS2

NLR1 Nl: opposition has been filed with the epo

Opponent name: NORSK HYDRO ASA

PLBB Reply of patent proprietor to notice(s) of opposition received

Free format text: ORIGINAL CODE: EPIDOSNOBS3

REG Reference to a national code

Ref country code: SI

Ref legal event code: IF

RDAF Communication despatched that patent is revoked

Free format text: ORIGINAL CODE: EPIDOSNREV1

APAH Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNO

APBP Date of receipt of notice of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA2O

APBQ Date of receipt of statement of grounds of appeal recorded

Free format text: ORIGINAL CODE: EPIDOSNNOA3O

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: ALUMINIUM PECHINEY

NLT2 Nl: modifications (of names), taken from the european patent patent bulletin

Owner name: ALUMINIUM PECHINEY

Effective date: 20060524

APAH Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNO

PLAB Opposition data, opponent's data or that of the opponent's representative modified

Free format text: ORIGINAL CODE: 0009299OPPO

APBU Appeal procedure closed

Free format text: ORIGINAL CODE: EPIDOSNNOA9O

PUAH Patent maintained in amended form

Free format text: ORIGINAL CODE: 0009272

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT MAINTAINED AS AMENDED

27A Patent maintained in amended form

Effective date: 20090805

AK Designated contracting states

Kind code of ref document: B2

Designated state(s): DE ES FR GB GR NL

AX Request for extension of the european patent

Extension state: RO SI

NLR2 Nl: decision of opposition

Effective date: 20090805

NLR3 Nl: receipt of modified translations in the netherlands language after an opposition procedure
REG Reference to a national code

Ref country code: ES

Ref legal event code: DC2A

Date of ref document: 20090825

Kind code of ref document: T5

REG Reference to a national code

Ref country code: GR

Ref legal event code: EP

Ref document number: 20090402716

Country of ref document: GR

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20091106

REG Reference to a national code

Ref country code: DE

Ref legal event code: R073

Ref document number: 69911758

Country of ref document: DE

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20130429

Year of fee payment: 15

REG Reference to a national code

Ref country code: DE

Ref legal event code: R124

Ref document number: 69911758

Country of ref document: DE

REG Reference to a national code

Ref country code: DE

Ref legal event code: R124

Ref document number: 69911758

Country of ref document: DE

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20150426

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20150427

Year of fee payment: 17

Ref country code: GB

Payment date: 20150427

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GR

Payment date: 20150429

Year of fee payment: 17

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20160425

Year of fee payment: 18

REG Reference to a national code

Ref country code: NL

Ref legal event code: MM

Effective date: 20160501

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20160407

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160501

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160407

REG Reference to a national code

Ref country code: SI

Ref legal event code: KO00

Effective date: 20161227

REG Reference to a national code

Ref country code: GR

Ref legal event code: ML

Ref document number: 20090402716

Country of ref document: GR

Effective date: 20161104

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20161104

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20171229

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20170502

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20160408

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20181128