CN103635610A - Electrolysis cell and cathode with irregular surface profiling - Google Patents

Abstract

The present invention relates to an electrolysis cell, in particular for the production of aluminium, comprising a cathode, a layer of liquid aluminium on the top side of the cathode, a melt layer on top of the layer of liquid aluminium, and an anode above the melt layer, wherein the cathode has, on the top side thereof, a surface profiling formed from two or more elevations, wherein the surface profiling of the cathode is configured and arranged such that in each case one elevation is provided at at least two of the twenty points on the surface of the top side of the cathode which are arranged in each case vertically below those regions of the boundary between the layer of liquid aluminium and the melt layer at which the peaks with the twenty highest maximum values are present in the reference wave forming potential distribution at the boundary, wherein a reference wave forming potential is defined as the wave forming potential which is present at a point in the boundary between the layer of liquid aluminium and the melt layer during the operation of the electrolysis cell with, instead of the cathode with surface profiling, a reference cathode without surface profiling but of otherwise identical configuration to the cathode with surface profiling.

Description

Electrolyzer and the negative electrode with irregular surface moulding

Technical field

The present invention relates to a kind of electrolyzer, the electrolyzer of producing in particular for aluminium, and the negative electrode that is applicable to this electrolyzer.

Background technology

Electrolyzer is for for example electrolytic production of aluminum, in the production of industrial aluminium, conventionally adopts Hall-He Lu secret service skill.Hall-He Lu secret service skill is by the melt electrolysis being comprised of aluminum oxide and sodium aluminum fluoride.Sodium aluminum fluoride, Na ₃[AlF ₆], for making 2,045 ℃ of the fusing points of pure alumina be reduced to approximately 950 ℃ of mixture fusing points, this mixture includes sodium aluminum fluoride, aluminum oxide and as the additive of aluminum fluoride and Calcium Fluoride (Fluorspan).

The electrolyzer using in this technique comprises a cathode base, and cathode base consists of a lot of cathode blocks, these cathode blocks formation negative electrode that arranges adjacent one another are.In order to make electrolyzer can bear calorifics and the electrochemical conditions generally using in operational process, negative electrode consists of carbonaceous material conventionally.The bottom side of each negative electrode is always provided with groove, and at least one bus is always set in groove, by bus, will derive from the electric current of anode input.The anode consisting of a plurality of independent anode blocks is arranged on liquid aluminium lamination top approximately 3 to 5 centimeters that are generally 15 to 50 cm thicks on negative electrode end face, and ionogen (melt that contains aluminum oxide and sodium aluminum fluoride) is between anode and aluminium liquid surface.When electrolysis is carried out at about 1,000 ℃, the density that the aluminium of generation is greater than electrolytic solution due to density is deposited on electrolyte layer below, between the end face of negative electrode and electrolyte layer, forms a middle layer.In electrolytic process, the aluminum oxide being dissolved in melt resolves into aluminium and oxygen under the effect of electric current.From electrochemical angle, liquid aluminium lamination is actually negative electrode, and this is because aluminum ion becomes pure aluminum at the surface reduction of liquid aluminium lamination.But term hereinafter " negative electrode " does not refer to the negative electrode of electrochemistry angle, not liquid aluminium lamination, but form the parts of electrolyzer substrate, the parts that for example formed by one or more cathode blocks.

The disadvantage of Hall-He Lu secret service skill is that it need to consume mass energy.Produce the electric energy that 1kg aluminium need to consume about 12-15kWh, account for 40% of production cost.Therefore in order to reduce production costs, should reduce as much as possible the specific energy consumption of this production technique.

Because special and liquid aluminium lamination and the cathode material melt of comparing has relatively high resistance, especially in melt, produce the ohmic loss of more Joule dissipation form.Owing to having produced relatively high specific loss in melt, therefore to reduce as far as possible melt layer thickness, reduce the distance between anode and liquid aluminium.But, due to the electromagnetic interaction in electrolytic process and when melt layer thickness is too small, can in liquid aluminium lamination, produce fluctuation, there is the danger that liquid aluminium touches anode, cause thus electrolyzer short circuit, make the aluminium forming that unnecessary oxidation again occur.This short circuit also can cause wearing and tearing to be accelerated, thereby shortens the work-ing life of electrolyzer.Therefore, the distance between anode and liquid aluminium can not reduce arbitrarily.

In order further to reduce special energy expenditure, also proposed to have recently the electrolyzer of negative electrode, when electric tank working, the end face of negative electrode is in the face of liquid aluminium and melt, and the end face of negative electrode has molding surface.For example, patent US 2011/0056826 A1 has disclosed a kind of negative electrode with regular surfaces moulding.Molding surface by Design with Rule can reduce the fluctuation in the horizontal and vertical directions of liquid aluminium lamination, strengthens thus the stability of liquid aluminium lamination.But owing to having the molding surface of Design with Rule, the moving formation of liquid aluminium lamination medium wave only must, in minimizing, particularly reduce unevenly on limited extent on whole cathode surface.In addition, due to liquid aluminium lamination hypokinesis, this on cathode block surface known regular surfaces moulding indirectly seriously hindered the mixing that is arranged in the melt layer above liquid aluminium lamination, this melt layer is necessary for the aluminum oxide of dissolving cycle supply, and this has disadvantageous effect for the electrolytic energy efficiency that can reach.

Patent EP 0 938 598 B1 and DE 101 64 008 C1 have disclosed the electrolyzer with negative electrode, and it is suitable for electrically contacting with its outside, and its special electric material resistance so mates, and make the electric current distribution of negative electrode end face even as much as possible.But, in these electrolyzers, in liquid aluminium lamination, having formed comparatively significantly fluctuation, thereby reduced the special energy expenditure of electrolyzer, can not be extended work-ing life.

Summary of the invention

Set out thus, the problem to be solved in the present invention is to provide a kind of electrolyzer that is in operation and reduces special energy consumption and increase the service life.Particularly should provide a kind of electrolyzer, in described electrolyzer, the thickness of melt layer has reduced, but do not have such as short circuit or established aluminium, such unstable does not occur to be again oxidized, and this unstable causes owing to occurring that in liquid aluminium lamination fluctuation formation trend strengthens.Meanwhile, describedly according to electrolyzer of the present invention, should guarantee that melt layer is fully mixed during operation.

According to the present invention, provide a kind of electrolyzer according to claim 1 to solve the problems referred to above, especially provide a kind of electrolyzer with negative electrode to come to produce for aluminium, described electrolyzer comprises a negative electrode, be positioned at the liquid aluminium lamination on the end face of described negative electrode, be positioned at the melt layer that comprises aluminum oxide and sodium aluminum fluoride above of described liquid aluminium lamination, and an anode that is positioned at the top of described melt layer.Wherein, the end face of described negative electrode has the molding surface consisting of two or more projections, the molding surface of described negative electrode is design and setting so: make to have at least two points to be provided with projection in lip-deep 20 points of negative electrode end face, the vertical lower in some regions of these boundary surfaces between liquid aluminium lamination and melt layer, in described region, the crest with 20 maximums appears at the reference fluctuation being present in boundary surface and forms in potentiality distribution, wherein, with reference to fluctuation formation potentiality, being defined as at electrolyzer (is not the negative electrode having with molding surface, but there is the reference negative electrode without molding surface, but other structures are identical with the negative electrode with molding surface) on period appears between liquid aluminium lamination and melt layer the fluctuation at a some place in boundary surface and forms potentiality.

According to the present invention, the negative electrode of electrolyzer comprises molding surface, especially, the single parts of described molding surface so mate targetedly on position, size and shape, make during electric tank working, avoid targetedly forming significantly fluctuation in the boundary surface between liquid aluminium lamination and melt layer and form the crest in potentiality, thus, compare with using the identical negative electrode without molding surface, from described boundary surface, observe, obtain uniform, few fluctuation and form potentiality distribution.

In the present invention, molding surface can be regarded as the summation that refers to all projections on negative electrode baseplane.Term " baseplane " refers to negative electrode horizontal plane farthest in anode direction, and this horizontal plane, through the whole cross section of negative electrode, does not intersect with the end face through molding surface of negative electrode.Therefore, all projections on described baseplane are all towards anode, and are surrounded by liquid aluminium lamination.The protruding height of described molding surface is the distance between protruding vertex and the point on the negative electrode baseplane of its vertical lower.

In solution according to the present invention, with respect to: hereinafter the fluctuation in the described boundary surface between liquid aluminium lamination and melt layer forms the impellent that potentiality is the moving formation of liquid aluminium lamination medium wave during electric tank working; Also with respect to the fluctuation of: traditional electrolyzer, form the skewness in the boundary surface of potentiality between liquid aluminium lamination and melt layer and be very inhomogenous especially.Because forming potentiality, fluctuation of the present invention reduces, especially because fluctuation formation potentiality is evenly distributed in the boundary surface between liquid aluminium lamination and melt layer, really avoided during electric tank working of the present invention, in liquid aluminium lamination, forming fluctuation, or greatly reduced the formation of fluctuation, therefore, compare with traditional electrolyzer, can reduce the thickness of melt layer, thereby greatly improved the efficiency of electrolyzer of the present invention.

The important result of another one of the present invention is: setting and special construction by the molding surface on electric tank cathode end face of the present invention can have a direct impact the uneven distribution of the inhomogenous fluctuation formation potentiality occurring in the boundary surface between traditional cell liquid state aluminium lamination and melt layer, and have avoided targetedly in this way the obvious crest of the fluctuation formation potentiality at boundary surface each point place.As described below, in aforementioned boundary surface, the fluctuation at a specified point place forms potentiality and depends on that current density and magneticflux-density are at the vector product at this some place.If consider a specific current path from negative electrode supply lines to anode electrolytic cell, along the total electrical resistance of this path and this path, through the current density at the some place of the boundary surface between liquid aluminium lamination and melt layer, depend on this path path length in cathode block, liquid aluminium lamination and melt layer respectively.Because the special resistance value of these materials is different, the special resistance of melt layer and cathode material is higher than liquid aluminium, and due to each current path in cathode block, liquid aluminium lamination is different with the path length in melt layer, total electrical resistance along individual channel, in traditional electrolyzer, each current density of the boundary surface between liquid aluminium lamination and melt layer is inhomogenous thus, thereby each point of boundary surface presents obvious current density crest.Each projection by anticathode molding surface arranges suitable position, shape and length, according to the present invention, so adjusting each current path (is cathode block in different piece, liquid aluminium lamination and melt layer) in path length, make to set up suitable electric current distribution in boundary surface region, so adjust this distribution of current of coupling, make during electric tank working, in boundary surface between liquid aluminium lamination and melt layer, can not form in potentiality distribution and occur obvious crest in fluctuation, guarantee that thus fluctuation forms the distribution of potentiality substantially even and low flat (niederig).

Protruding position, shape and length for optimized cathode molding surface, the reference fluctuation that the present invention produces during operation from the electrolyzer of the conventional cathode with without moulding forms potentiality and starts with, on the point of cathode surface, projection is set targetedly, described projection is arranged on the vertical lower that occurs the point of obvious crest in boundary surface in forming potentiality distribution with reference to fluctuation.During having the electric tank working of the negative electrode that passes through molding surface, the current density in these regions has reduced, so the fluctuation in these regions formation potentiality has also reduced.

As mentioned above, at electrolyzer, (there is the reference negative electrode without molding surface, rather than with the negative electrode of molding surface, the cathode surface with level, but identical with the negative electrode with molding surface with reference to other structures of negative electrode) the reference fluctuation that on period produces forms potentiality and is fluctuation and forms potentiality.According to the embodiment in claim 1, described identical with electrolyzer according to the present invention for determining with reference to the reference electrolyzer of fluctuation formation potentiality, what difference was use is the reference negative electrode of not process molding surface rather than the negative electrode that has passed through molding surface, in with reference to electrolyzer, the end face of negative electrode is filled up by liquid aluminium or melt owing to lacking the additional volumes that molding surface increases---and which layer this depends on through the corresponding material on the negative electrode of molding surface in.

Especially, while having many projections to occupy a large amount of volume on negative electrode end face, claim 2 has proposed an alternative embodiment of the invention, with the reference negative electrode without molding surface, determine with reference to fluctuation and form potentiality, so adjust this with reference to negative electrode the height in electrolyzer, the liquation volume that makes liquid aluminium between described negative electrode end face and anode and melt is identical with the liquation volume of electrolyzer of negative electrode with molding surface.Due to reference fluctuation in this case form potentiality with and the electrolyzer of the present invention reference electrolyzer with identical liquation volume be correlated with, if the protruding volume of cathode surface moulding accounts at least 10% of cathode volume, preferably at least 20%, particularly preferably at least 30%, the reference fluctuation of determining thus forms the potentiality fluctuation more definite than electrolyzer according to claim 1, and to form potentiality more meaningful.

Fluctuation forms potentiality and the fluctuation that obtains thus form potentiality distribute can be by computer supported the motion simulation of electricity, magnetics and magnetic-fluid power and the liquid aluminium of each electrolyzer layer in melt in fluctuation form and determine.

According to the present invention, the fluctuation of any point in the boundary surface between liquid aluminium lamination and melt layer is formed to the absolute value that potentiality is defined as those velocity components of the melt occurring in melt boundary surface, be present in this point, this component aligns with the normal of boundary surface, i.e. fluctuation formation potentiality= wherein

the melt flow as vector,

it is normal vector.In addition, suppose that boundary surface is permeable, thereby fluctuation forms potentiality, represent a kind of local yardstick boundary surface, that drive fluctuation that points to.In this case, the mobile nature of melt can not be determined by experimental technique, so fluctuation formation potentiality is preferably determined by analogy method described below.

In order to calculate flow condition, first by simulation, according to finite element method (FEM), calculate Electric and magnetic fields, then by the Electric and magnetic fields calculating for calculating flow condition, also can according to finite element method (FEM), calculate flow condition by simulation.Can use the software Comsol Multiphysics that version is 3.5a to carry out this two kinds of simulations.Suppose that boundary surface is permeable, wherein, fluctuation forms potentiality and represents a kind of local yardstick boundary surface, that drive fluctuation that points to.Simulation electrolyzer comprises bus, have the anode tree (existing if desired) of the electrolyzer with electricity line (if desired exist) of magnetic compensation geometric construction, negative electrode, liquid aluminium lamination, melt layer, anode, jointed anode and as the air of surrounding medium, with method of geometry by parts of parts of described electrolyzer split into Finite Volume Element.Consider above-mentioned parts, as long as for simulation electrolyzer, it has one or more planes of symmetry, only always partly simulates being positioned at the electrolyzer of each plane of symmetry one side, by corresponding final condition, with respect to Symmetry Condition, will more describe in detail this hereinafter.

Simulation simply from the steady state conditions of electrolyzer, is basis thereby simulation is able to take the physical equation of each stable state.In addition suppose, the working temperature constant (970 ℃) of electrolyzer.

Simulation is based on following variable and parameter:

V: voltage, scalar

: specific conductivity, scalar

E(boldface letter): electric field, vector

A(boldface letter): vector current potential, vector

A _x, A _y, A _z: vector current potential, component

H(boldface letter): magnetic field, vector

J, j(boldface letter),

current density, vector

B(boldface letter),

magneticflux-density, vector

I(boldface letter): unit matrix, tensor

F(boldface letter): force density (lorentz force density and gravimetric density sum), vector

U(boldface letter),

flow velocity, vector

U(normal font), u _x, u _y, u _z: flow velocity, component

P: pressure, scalar

μ: viscosity, scalar

: density, scalar

L _c: characteristic length, for example the aluminium liquid degree of depth

V _c: characteristic velocity

Supplementary variable in turbulent flow situation:

μ _t: turbulent viscosity, scalar

K: Turbulent Kinetic

Ep: Turbulent Kinetic dissipates

Lw: apart from the spacing at fixed edge interface

L _ref: reference length yardstick, with characteristic length L _ccorresponding

G: the mutual spacing at fixed edge interface

P _k: the source item of Turbulent Kinetic

F _u: attenuation function viscosity

F _ε: attenuation function dissipates

R _t: turbulent flow Reynolds number

L ^*: limited mixinglength

U _ε: the turbulence dissipation rate of all grid cells

N (bold type) (boldface letter),

the normal vector of the boundary surface between liquid aluminium lamination and melt layer, vector

T (bold type) (boldface letter),

tangent line vector, vector

unit vector, cartesian coordinate system

The grid building up is carried out to fully and carefully dimensioning, thereby the instrument (Artefakte) of grid is no longer visible when fluctuation potentiality is calculated.This comprises, the obvious crest for example occurring along grid edge or significantly change.In addition, simulated data shows that for adjusting the rear dependence of grid fineness and the slow convergence of simulation and finite convergence the grid fineness in relevant range is inadequate.

And when setting up grid, whole grid requires quality factor to be at least 0.15, wherein quality factor q carries out as given a definition according to Comsol Multiphysics software application handbook:

Table 1

Wherein, the volume of V=grid cell

H _ithe length of side of=grid cell

At length, grid is built according to the following steps:

The air of electrolysis bath circumference is not with limitting the grid of size to carry out modeling, and this size changes between refining region (as melt layer) and rough region (as integrally-built neighboring area).Scale-up factor between two adjacent mesh is no more than 1.65, to avoid grid cell distortion.

Supply lines and electric current outlet line electric current outlet line copy with the grid cell that the length of side is about 30cm.

Liquid towards aluminium lamination and melt layer are modeled as, and the length of side that makes to form each grid of the boundary surface between liquid aluminium lamination and melt layer is about 3cm.To melt layer modeling, make a grid in vertical direction on average extend to half that is equivalent to melt layer thickness more.

In the scope of simulation, supposed, the boundary surface between liquid aluminium lamination and melt layer is crooked, and thereby is horizontal-extending.Therefore, normal vector n is vertical cell vector e _zso fluctuation forms the vertical component u that potentiality is defined as the flow velocity in boundary surface _zabsolute value.

The layer modeling that liquid towards aluminium lamination and negative electrode form, the Grid Edge that forms boundary surface between negative electrode and liquid aluminium lamination is about as 5cm.

If not, anode and negative electrode be not with limitting the grid of size to carry out modeling, and wherein, the size of mesh opening of refining region (as melt layer) and rough region (as supply lines and electric current outlet line electric current outlet line) can have difference.Scale-up factor between two adjacent mesh is no more than 1.65, to avoid grid cell distortion.

For with undefined electrolyzer of working under turbulent-flow conditions, the what is called providing by Comsol Multiphysics in cell construction " expansion frictional belt (Inflation Boundary Layers) ", to the fixed edge interface modeling between each parts, wherein forms (with respect to for example tetrahedron element) by prism elements.

Each grid of grid structure has respective material character, that is to say, grid has special resistance, represents that the grid of liquid aluminium lamination and melt layer also additionally has k value and the density value of aluminium and melt.

Below the essential property of material:

Table 2

The other materials character that simulation is used is chosen as, and makes it be equivalent to the actual nature of each material.

For the numerical stability that electromagnetism calculates and hydromeehanics calculates, the flip-flop of the material character of the boundary surface between liquid aluminium lamination and melt layer in reality be leveling within the scope of ± 3cm in model configuration, that is to say, grid in the liquid aluminium lamination of the representative below or above within the scope of boundary surface 3cm and melt layer has material property values, these numerical value are chosen as, and make the character of the grid that represents liquid aluminium in table 2 within the scope of this, be converted to substantial linear the character of the grid that represents melt layer in table 2.

The air of electrolysis bath circumference has the special resistance that artificial 1Ohmm is high, so it can not conduct electricity.

The grid structure of setting up in this way, to have reproduced described electrolyzer on its geometrical shape and material character thereof, for this grid structure calculates electromagnetic field, and is guaranteed in the hydromeehanics motion calculation of the numerical value substitution bath of cell drawing.

The first step of Electromagnetic Modeling is based on known stable state Maxwell equation below:

$\▿\·J=0$

$\▿\×H=J$

J＝σE+J _e

$E=-\▿V$

$B=\▿\×A$

Shape function by Lagrangian (V is single order, and A is second order) as finite element method.

By numerical evaluation, these partial differential equation of relevant whole geometric construction are solved.Therefore, the final condition that will use will be described in detail below; Especially, using the electric tank working electric current by the input of negative electrode and anode as outside default operating parameter calculate.

Therefore the basis that, the hydromeehanics using lorentz force density as electrolyzer liquation calculates.

According to flowing property, hydromeehanics calculates the equation based on different.For selecting the partial differential equation that will use, adopt well-known Reynolds number

use accordingly following system of equations:

Use equation (Navier-Stokes equation) below to solve the Re < laminar flow of 10,000 o'clock and weak turbulent flow:

$\mathrm{\&rho;}(u\&CenterDot;\&dtri;)u=\&dtri;\&CenterDot;[-\mathrm{\&rho;l}+\mathrm{\&mu;}(\&dtri;u+{(\&dtri;u)}^T)-\frac{2}{3}\mathrm{\&mu;}(\&dtri;\&CenterDot;u)l]+F$

$\&dtri;\&CenterDot;\left(\mathrm{\&rho;u}\right)=0$

Shape function by Lagrangian (p is single order, and u is second order) as finite element method.

Following equation (low reynolds number k-ε equation) is applied to Re >=10, and 000 and <100, flowing in 000 transitional region.

$\mathrm{\&rho;}(u\&CenterDot;\&dtri;)u=\&dtri;\&CenterDot;[-\mathrm{\&rho;l}+(\mathrm{\&mu;}+{\mathrm{\&mu;}}_T)(\&dtri;u+{(\&dtri;u)}^T)-\frac{2}{3}(\mathrm{\&mu;}+{\mathrm{\&mu;}}_T)(\&dtri;\&CenterDot;u)l-\frac{2}{3}\mathrm{\&rho;kl}]+F$

$\&dtri;\&CenterDot;\left(\mathrm{\&rho;u}\right)=0$

$\mathrm{\&rho;}(u\&CenterDot;\&dtri;)k=\&dtri;\&CenterDot;[(\mathrm{\&mu;}+\frac{{\mathrm{\&mu;}}_T}{{\mathrm{\&sigma;}}_k})\&dtri;k]+P_k-\mathrm{\&rho;\&epsiv;}$

$\mathrm{\&rho;}(u\&CenterDot;\&dtri;)\mathrm{\&epsiv;}=\&dtri;\&CenterDot;[(\mathrm{\&mu;}+\frac{{\mathrm{\&mu;}}_T}{{\mathrm{\&sigma;}}_e})\&dtri;\mathrm{\&epsiv;}]+C_{e1}\frac{\mathrm{\&epsiv;}}{k}{P}_k-C_{e2\mathrm{\&rho;}}\frac{{\mathrm{\&epsiv;}}^2}{k}{f}_e(\mathrm{\&rho;},\mathrm{\&mu;},k,\mathrm{\&epsiv;},l_w),\mathrm{\&epsiv;}=\mathrm{ep}$

$\&dtri;G\&CenterDot;\&dtri;G+{\mathrm{\&sigma;}}_{w}G(\&dtri;\&CenterDot;\&dtri;G)=(1+{2\mathrm{\&sigma;}}_w){\mathrm{<figure-callout\; id="4"\; label="G"\; filenames="HDA0000421778230000041.png"\; state="\{\{state\}\}">G</figure-callout>}}^4,l_w=\frac{l}{G}-\frac{l_{\mathrm{ref}}}{2}$

${\mathrm{\&mu;}}_T=\mathrm{\&rho;}{C}_{\mathrm{\&mu;}}\frac{k^2}{\mathrm{\&epsiv;}}{f}_{\mathrm{\&mu;}}(\mathrm{\&rho;},\mathrm{\&mu;},k,\mathrm{\&epsiv;},l_w),P_k={\mathrm{\&mu;}}_T[\&dtri;u:(\&dtri;u+{(\&dtri;u)}^T)-\frac{2}{3}{(\&dtri;\&CenterDot;u)}^2]-\frac{2}{3}\mathrm{\&rho;k}\&dtri;\&CenterDot;u$

$f_{\mathrm{\&mu;}}={(1-e^{-l^{*}/14})}^2\&CenterDot;(1+\frac{5}{R_t^{3/4}}{e}^{-{(R_t/200)}^2})$

$f_{\mathrm{\&epsiv;}}={(1-e^{-l^{*}/3.1})}^2\&CenterDot;(1-0.3e^{-{(R_t/6.5)}^2})$

l ^*＝(ρu _εl _w)/μ?R _t＝ρk ²/(με)?u _ε＝(με/ρ) ^1/4

Shape function by Lagrangian (p is single order, and u, k and ep are second order) as finite element method.

Following equation (k-ε equation) is for Re >=100,000 turbulent flow:

$\mathrm{\&rho;}(u\&CenterDot;\&dtri;)u=\&dtri;\&CenterDot;[-\mathrm{\&rho;l}+(\mathrm{\&mu;}+{\mathrm{\&mu;}}_T)(\&dtri;u+{(\&dtri;u)}^T)-\frac{2}{3}(\mathrm{\&mu;}+{\mathrm{\&mu;}}_T)(\&dtri;\&CenterDot;u)l-\frac{2}{3}\mathrm{\&rho;kl}]+F$

$\&dtri;\&CenterDot;\left(\mathrm{\&rho;u}\right)=0$

$\mathrm{\&rho;}(u\&CenterDot;\&dtri;)k=\&dtri;\&CenterDot;[(\mathrm{\&mu;}+\frac{{\mathrm{\&mu;}}_T}{{\mathrm{\&sigma;}}_k})\&dtri;k]+P_k-\mathrm{\&rho;\&epsiv;}$

$\mathrm{\&rho;}(u\&CenterDot;\&dtri;)\mathrm{\&epsiv;}=\&dtri;\&CenterDot;[(\mathrm{\&mu;}+\frac{{\mathrm{\&mu;}}_T}{{\mathrm{\&sigma;}}_e})\&dtri;\mathrm{\&epsiv;}]+C_{e1}\frac{\mathrm{\&epsiv;}}{k}{P}_k-C_{e2\mathrm{\&rho;}}\frac{{\mathrm{\&epsiv;}}^2}{k},\mathrm{\&epsiv;}=\mathrm{ep}$

${\mathrm{\&mu;}}_T=\mathrm{\&rho;}{C}_{\mathrm{\&mu;}}\frac{k^2}{\mathrm{\&epsiv;}}{,P}_k={\mathrm{\&mu;}}_T[\&dtri;u:(\&dtri;u+{(\&dtri;u)}^T)-\frac{2}{3}{(\&dtri;\&CenterDot;u)}^2]-\frac{2}{3}\mathrm{\&rho;k}\&dtri;\&CenterDot;u$

Wherein, C _μ=0.09; C _{ε 1}=1.44; C _{ε 2}=1.02; σ _k=1.0and σ _ε=1.3.

Shape function by Lagrangian (p is single order, and u, k and ep are second order) as finite element method.

The numerical value calculating when previously considering electromagnetic factors is with lorentz force density

form substitution aforesaid equation.According in aforesaid equation lorentz force density

and gravimetric density

form together external excitation F.

Similarly, above hydromeehanics partial differential equation are carried out to numerical solution.

In foregoing calculating, also use with downstream condition:

With downstream condition, relate to the electric field calculating in electromagnetism calculates:

The outside surface of the volume of processing is considered as to electrical insulator (nJ=0).

The occurred plane of symmetry is considered as to electrical insulator (nJ=0).

Voltage V is put on to the input terminus of anode tree, its coupling is, for example, for generation of the cell current (168kA) that makes electrolyzer normal operation.

0 volt of voltage V puts on cathode side electric current outlet line electric current outlet line (ground connection).

The electromotive force V calculating has continuity at all internal surfaces.

With downstream condition, relate to the magnetic field calculating when electromagnetism calculates:

Magnetic flux is parallel with outside surface in the outer surface of the volume of processing

Magnetic symmetry come across any symmetrical surface that may occur.

The vector potential A calculating has continuity at all internal surfaces.

With downstream condition, relate to the flow field calculating when hydromeehanics calculates:

Fixed boundary mask has following characteristics:

When o is used laminar flow equation: liquid is bonded on fixed edge interface firmly, this can be expressed as " without slippage ", i.e. speed u=0.

O is when being used Equations of Turbulence formula: use a wall model, this model has been considered the friction between each liquid level and fixed edge interface.

Open boundary face can appear on any one plane of symmetry that may occur, wherein the normal direction of boundary surface flows and presses f ₀=0 calculates according to following equation:

The flow velocity u calculating for example, has continuity at all internal surfaces (, the boundary surface between liquid aluminium lamination and melt layer).

As mentioned above, first by EMV electromagnetic value V, A _x, A _y, A _z, j _x, j _yand j _zby Maxwell equation, calculate, then by obtaining thus the each fluid mechanics equation using of lorentz force density substitution, to calculate flow field value u _x, u _y, u _zand p.Therefore, by a kind of unidirectional mode, electromagnetism calculating and hydromeehanics calculations incorporated are got up.

Utilization has the pretreated iterative programs of many grid geometries (GMRES) partial differential equation mentioned above is solved.If necessary, Fluid Mechanics is used standard stabilization technology, for example, vector potential calibration during the streamline providing in Comsol Multiphysics diffusion (GLS) and crosswind diffusion and electromagnetism calculate.

According to the present invention, according to the molding surface of negative electrode of the present invention, comprise two or more projections, wherein, in lip-deep 20 points of negative electrode end face, have at least two points to be provided with projection, the vertical lower in some regions of these boundary surfaces between liquid aluminium lamination and melt layer, in described region, the crest with 20 maximums appear at be present in boundary surface reference fluctuation form during potentiality distributes.In the expansion of this invention thought, proposed: in the lip-deep Y of negative electrode end face point, have at least X point to be provided with projection, the vertical lower in some regions of these boundary surfaces between liquid aluminium lamination and melt layer, in described region, the crest with Y maximum appear at be present in boundary surface reference fluctuation form during potentiality distributes

Wherein, X=4 and Y=20, preferably, X=6 and Y=20, particularly preferably, X=10 and Y=20, most preferably, X=14 and Y=20, and/or

Wherein, X=2 and Y=10, preferably, X=3 and Y=10, particularly preferably, X=5 and Y=10, most preferably, X=7 and Y=10, and/or

Wherein, X=1 and Y=5, preferably, X=2 and Y=5, particularly preferably, X=3 and Y=5, most preferably, X=4 and Y=5.In this way, avoided all sidedly especially occurring obvious crest in the fluctuation of electrolyzer forms potentiality, so further improved the stability during electric tank working.

According to another preferred embodiment of the present invention, the lip-deep point of negative electrode end face place is provided with at least one projection, the vertical lower in some regions of the boundary surface of described projection between liquid aluminium lamination and melt layer, in described region, each crest appears at the reference fluctuation being present in boundary surface and forms in potentiality distribution, the point place of the vertical lower of the point of the projection of arranging in boundary surface between liquid aluminium layer and melt layer has its maximum height, and the crest that the reference fluctuation at this some place forms potentiality distribution has maximum value.Therefore effectively avoided forming especially too much fluctuation in the respective regions of boundary surface.

Particularly preferably, all crest-projections are to all having the structure setting of above-mentioned basic congruence, that is to say, all projections that are arranged on the lip-deep point of cathode top place are all arranged on the vertical lower in some regions of boundary surface between liquid aluminium lamination and melt layer, in these regions, each crest appears at the reference fluctuation being present in boundary surface and forms in potentiality distribution, the point place of the vertical lower of the point of the projection of arranging in boundary surface between liquid aluminium layer and melt layer has maximum height, each crest that forms potentiality distribution with reference to fluctuation has maximum value at these some places.

If from vertical view, the outline with geometrical shape of at least one projection is at least substantially similar or substantially corresponding with the outline with geometrical shape of each crest distributing with reference to fluctuation formation potentiality, the crest forming with reference to fluctuation in potentiality distribution is had to especially effectively compensation.

The meaning of similarity is consistent with the usage of professional term, and these two outlines can transform mutually by geometric maps, and wherein by concentric elongation and congruence mapping (Kongruenzabbildung), for example, particularly translation, rotation or mirror image form.For example, described two outlines can be substantially similar to a circle.Described two outlines also can form two trilaterals substantially, these two trilaterals have two essentially identical angles, or substantially form two rectangles, these two rectangles have long-width ratio at least about equally, or substantially form two ellipses, these two ellipses have at least roughly the same excentricity numerical value.

Particularly preferably be, from vertical view, the outline with geometrical shape of all projections is at least substantially similar or substantially consistent in vertical view with the outline of the geometrical shape of each crest distributing with reference to fluctuation formation potentiality.

According to another preferred embodiment of the present invention, from vertical view, the outline with geometrical shape of at least one projection is at least designed at least be similar to Polygons and/or oval-shaped shape on cross section.These projections are easy to especially realize and are particularly suitable for effective compensation and with reference to fluctuation, form the crest of potentiality.When protruding structure is to be easy to especially realize while having the Polygons at 3,4,5 or 6 angles.

Within the scope of the present invention, overlook the protruding outline of seeing and be advantageously chosen as, can be by simplifying (overlook and see) outline of forming each crest that potentiality distributes with reference to fluctuation produce.Therefore, preferably, at least one projection has outline, and from the geometrical shape of this outline of vertical view, than (seeing), being arranged in reference fluctuation in boundary surface, that be positioned at vertically protruding top in vertical view, to form the geometrical shape of outline of the crest that potentiality distributes simple.Preferably, from number and the variant curved part summation of outline at all angles of the protruding outline of vertical view, be less than (overlook and see) forms the outline of the crest that potentiality distributes number and the variant curved part summation of outline at all angles with reference to fluctuation.The differently curved part that is all looked at as an outline along all zones of circumferential outline one by one has flex point between described region.

In order effectively to prevent that the crest that forms potentiality with reference to fluctuation from causing that liquid aluminium undulated layer forms increase, advantageously verified, at least one protruding 3D shape is at least substantially similar or basically identical to the 3D shape of each crest distributing with reference to fluctuation formation potentiality.

Particularly preferably be, the 3D shape of all projections is at least substantially similar or basically identical to the 3D shape of each crest distributing with reference to fluctuation potentiality.

Another useful embodiment according to the present invention, at least one projection has vertically upward-fining 3D shape.This structure has been avoided forming with reference to the fluctuation forming in potentiality distribution medium wave peak region especially effectively.From the side, described at least one projection can have one and is for example essentially polygonal, is preferably the outline that is substantially trapezoidal.

In the continuation expansion of this invention thought, advised, vertically look up, at least one projection be take end face as boundary, and from vertical view, this end face has the top surface area of the base area that is less than (seeing from vertical view) projection.For example, described projection can be made into and is for example at least roughly taper shape or terrace with edge shape.

According to a further embodiment of the invention, at least one projection has the 3D shape that starts from protruding bottom surface, and described 3D shape is rotated and generates around the turning axle that limits the bottom surface of turning axle by bottom surface.Preferably, described turning axle is essentially horizontal-extending.This geometrical shape of projection is particularly suitable for effectively making fluctuation formation potentiality be evenly distributed and be easy to especially manufacture.Preferably, described at least one projection is rotated at least 75 ° 180 ° and generate at the most by bottom surface around turning axle.

Another useful embodiment of the present invention is characterised in that, at least one projection has the 3D shape that starts from protruding bottom surface, and described 3D shape is vertically upwards carried out geometry by protruding bottom surface and extruded and generate.Preferably, described in extrude direction and be at least essentially vertical direction, depart from vertical direction and be no more than 45 °.Preferred described projection is dwindled gradually along extruding in direction size in proportion in extrusion.Preferably, in extrusion, at least one projection is vertically upwards tapered in principle.Described projection also may adopt vacuum vibration, and single shaft compacting or other applicable moulding processs are manufactured.

In electrolyzer, negative electrode can consist of two or more cathode blocks, and/or anode can consist of two or more anode blocks.At this, from cathode block laterally, a plurality of cathode blocks can arrange continuously one by one and along its longitudinal side, connect by smashing material at this.In addition, preferably, from the width of cathode block, an anode block covers two cathode blocks, and from the longitudinal direction of cathode block, two anode blocks cover a cathode block.

If the distance between anode and liquid aluminium lamination is 15mm to 45mm, preferred 15mm to 35mm, 15mm to 25mm particularly preferably, electrolyzer can reach extra high Energy efficiency.By reduction, fluctuate to form potentiality and make fluctuation form being evenly distributed of potentiality and reach above-mentioned short range.

As mentioned above, cathode surface moulding coupling according to the present invention is to have avoided each some place of the boundary surface between liquid aluminium lamination and melt layer to occur that significantly fluctuation forms the obvious crest of potentiality.At this, obtain on its position, size and dimension the molding surface that the special properties with electrolyzer adapts to.The present invention has abandoned the approach that a priori defines molding surface consciously, targetedly, this molding surface tactical rule, but incompatible with the various fluctuations formation potentialities that occur.On the contrary, electric tank cathode molding surface according to the present invention is irregularly formed in practice at least in one direction.

The invention still further relates to a kind of negative electrode for aluminium cell, the end face of described negative electrode comprises the first batten and at least one molding surface along the second batten of at least substantially vertical direction extension of the first direction with negative electrode substantially extending along the first direction of negative electrode with two or more.

In the present invention, batten is counted as at least substantially longitudinally linearly extended projection.

In the scope of the invention, there is the negative electrode of this molding surface when for electrolyzer, be suitable for obtaining fluctuation and form potentiality distribution in the boundary surface between liquid aluminium lamination and melt layer during described electric tank working, therefore effectively avoid occurring at boundary surface each point place significantly fluctuation formation potentiality crest.Molding surface described in detail herein is suitable for the common condition of many electrolyzers that generally use, and is designed to, and considers that these conditions form potentiality distribution to obtain uniform fluctuation in electrolyzer.

This negative electrode especially can be as parts of the previously described electrolyzer of describing according to the present invention.

Therefore, negative electrode according to the present invention is very suitable for realizing following advantage when for electrolyzer: improve Energy efficiency, increase the service life; Guarantee the abundant mixing of melt in electrolyzer simultaneously.

According to a useful embodiment of the present invention, described at least two the first battens extend along the horizontal direction at least haply of negative electrode.

In the expansion scheme of this invention thought, advised, from vertical view, the end face of negative electrode have one basic be rectangular outline, wherein, the basic of negative electrode is provided with projection at least one place, angle in four angles of rectangular outline.Within the scope of the present invention, confirmed that the obvious crest forming in potentiality distribution with reference to fluctuation appears in these angular regions conventionally, thereby electrolyzer stability during operation can be improved significantly by measure of the present invention.From vertical view, described in be arranged on angular region projection preferably there is an outline being generally triangular.

In another useful embodiment of the present invention, be provided with, negative electrode end face comprises the depression of a peviform, and described depression is seen at least substantially V-shaped from negative electrode cross section.The depression that described V-arrangement benzvalene form forms is for reducing the current density of negative electrode lateral border, and if not this current density is increased because the bus with inserting cathode bottom contacts, and can reduce thus the fluctuation formation potentiality in these regions.

Described at least two the first battens and at least one second batten are preferably arranged on the surface of the basic depression for V-arrangement.

The middle that tie point between two supporting legs of the cross section of the depression that according to a further advantageous embodiment, described Basic Design is V-arrangement basin is seen to be at least generally arranged at negative electrode from negative electrode cross section.In this way, current density is from negative electrode cross section lateral border zone-transfer to middle portion, the crest of current density in these fringe regions when reducing negative electrode and use in electrolyzer with this, obtains low fluctuation and forms potentiality and basic fluctuation uniformly and form potentiality and distribute.

In the present invention, confirm useful, described in be recessed at least 75%, preferably at least 90%, particularly preferably at least 95%, most preferably on 100% cathode surface, extend.When negative electrode is used in electrolyzer, make in this way the fluctuation on whole cathode surface form being evenly distributed of potentiality.

From the second party of negative electrode, look up, described at least one second batten is preferably at least generally arranged at the middle portion of negative electrode.Owing to easily occurring that in this region too high fluctuation forms potentiality, therefore for fluctuation, forming potentiality has particularly advantageous impact.

According to another useful embodiment, the bottom of the upper limb of at least one the first batten and V-arrangement basin has a distance, and from negative electrode transversely, described distance increases gradually to the middle portion of negative electrode.The distance increasing gradually towards the middle portion of cathode block can be avoided forming too much fluctuation in cathode block middle portion and form potentiality crest, thus avoid when cathode block during for electrolyzer the moving formation of liquid aluminium lamination medium wave in this region increase.

Another theme of the present invention is electrolyzer, and in particular for producing the electrolyzer of aluminium, described electrolyzer comprises the negative electrode that at least one is above-mentioned, and liquid aluminium lamination is positioned on the end face of negative electrode, melt layer be positioned at liquid aluminium lamination above, an anode is positioned at melt layer top.About above-described embodiment and the advantage of negative electrode is applicable to electrolyzer of the present invention too.

According to a useful embodiment of the present invention, described anode comprises at least two anode blocks that are set up in parallel, wherein, a web member extends between described at least two anode blocks, and at least one of described negative electrode the first batten is arranged on two web member vertical lower between anode block at least substantially parallel with it.Preferably, the angular variation between the orientation of described batten and the orientation of web member is about 20 °.According to the present invention, have realized that the fluctuation in these regions between anode block forms potentiality obviously increase conventionally, thereby aforesaid method still contributes to strengthen further the stability of electrolyzer.Described at least one first batten that is arranged on web member vertical lower preferably arranges in a kind of mode placed in the middle that is at least similar to relevant to web member.

Another theme of the present invention is the manufacture method with the electrolyzer of feature described in claim 31.

Electrolyzer manufacture method a kind of electrolyzer, that produce in particular for aluminium, this electrolyzer comprises a negative electrode, be positioned at the liquid aluminium lamination on the end face of described negative electrode, be positioned at the melt layer above of described liquid aluminium lamination, and an anode that is positioned at the top of described melt layer, described manufacture method comprises the following steps:

-determine reference fluctuation in the boundary surface between the liquid aluminium lamination of present electrolyzer and melt layer to form potentiality and distribute;

-manufacture comprise a plurality of projections, be positioned at the molding surface on negative electrode end face, wherein, in lip-deep 20 of cathode top, have at least two points to be provided with projection, the vertical lower in some regions of described boundary surface between liquid aluminium lamination and melt layer, in these regions, have 20 the crest of high extreme value appear at during the reference fluctuation potentiality being present in boundary surface distributes

Wherein, the fluctuation of a bit locating that is defined as appearing in the boundary surface between liquid aluminium lamination and melt layer during electric tank working with reference to fluctuation potentiality forms potentiality, described electrolyzer has the reference negative electrode without molding surface, rather than with the negative electrode of molding surface, but there is in addition the design identical with negative electrode with molding surface.

Can be by made according to the method for the present invention according to electrolyzer mentioned above of the present invention.Therefore about advantage mentioned above and embodiment according to electrolyzer of the present invention are applicable to the method according to this invention.

According to claim 32, the electrolyzer manufacture method that another theme of the present invention is a kind of electrolyzer, produce in particular for aluminium, described electrolyzer comprises a negative electrode, be positioned at the liquid aluminium lamination on the end face of described negative electrode, be positioned at the melt layer above of described liquid aluminium lamination, and an anode that is positioned at the top of described melt layer, described electrolyzer manufacture method comprises the following steps:

-determine reference fluctuation in the boundary surface between the liquid aluminium lamination of present electrolyzer and melt layer to form potentiality and distribute;

-manufacture comprise a plurality of projections, be positioned at the molding surface on negative electrode end face, wherein, at least two points in lip-deep 20 of cathode top are provided with projection, the vertical lower in some regions of described border surface between liquid aluminium lamination and melt layer, in these regions, have 20 the crest of high extreme value appear at during the reference fluctuation potentiality being present in boundary surface distributes

Wherein, the fluctuation of a bit locating that is defined as appearing in the boundary surface between liquid aluminium lamination and melt layer during electric tank working with reference to fluctuation potentiality forms potentiality, described electrolyzer has without the reference negative electrode of molding surface rather than with the negative electrode of molding surface, described other structures with reference to negative electrode are identical with the negative electrode with molding surface, wherein, describedly with reference to negative electrode, on the height in electrolyzer, be set to, make liquid aluminium lamination and the melt layer volume when reference electrode and volume between anode are set to have the negative electrode with molding surface with electrolyzer identical.

Accompanying drawing explanation

Below in conjunction with accompanying drawing, by useful embodiment, only with the form of giving an example, the present invention will be described.In accompanying drawing:

Fig. 1 is the electrolyzer skeleton view according to the embodiment of the present invention;

Fig. 2 is the local distribution vertical view that the reference fluctuation in the boundary surface between electrolyzer shown in Fig. 1, liquid aluminium lamination and melt layer forms potentiality;

Fig. 3 is the negative electrode vertical view through molding surface of electrolyzer shown in Fig. 1;

Fig. 4 is the skeleton view of negative electrode shown in Fig. 3;

Fig. 5 is that the fluctuation in the boundary surface between the liquid aluminium lamination of electrolyzer shown in Fig. 1 to Fig. 4 and melt layer forms potentiality local distribution figure;

Fig. 6 a-i has shown the exemplary bumps according to molding surface of the present invention;

Fig. 7 a-i has shown the other exemplary bumps according to molding surface of the present invention.

Embodiment

Figure 1 shows that the electrolyzer 10 of producing for aluminium, described electrolyzer comprises a negative electrode 12, be positioned at the liquid aluminium lamination 14 on the end face of described negative electrode 12, be positioned at the melt layer 16 above of described liquid aluminium lamination, and an anode 18 that is positioned at the top of described melt layer 16.Liquid aluminium lamination 14 and melt layer merge mutually at boundary surface 15 places.

Negative electrode 12 consists of a plurality of microscler cathode blocks, and described microscler cathode block extends along the horizontal direction y of electrolyzer 10, is arranged side by side, and interconnects by the material web member of smashing not showing in figure along longitudinal x of electrolyzer 10.A bus 20 is inserted in the bottom side of each cathode block, and described bus passes cathode block along longitudinal y of cathode block, produces and electrically contacts with cathode block.

Bus 20 gathers together by electric current outlet line 22, and described electric current outlet line is geometrically set to, and can cause field compensation, that is, make the distribution of the magnetic induction density B that produced by electric current with to a certain degree homogenization.

Anode 18 comprises a plurality of anode blocks, and described anode block interconnects by supply lines 28, and described supply lines comprises an anode tree 26.

The negative electrode 12 of electrolyzer 10 has molding surface, and described molding surface comprises a plurality of protruding 30, as described below, and the distribution that the reference fluctuation of the electrolyzer 10 in described molding surface and boundary surface 15 forms potentiality adapts.

In the present embodiment example, can utilize this situation, at the electrolyzer 10 shown in Fig. 1, about the plane of symmetry 32 mirror symmetries, this can be used for computing reference fluctuation and forms potentiality.Therefore, when computing reference fluctuation forms potentiality, half electrolyzer that is arranged in electrolyzer 10 plane of symmetry 32 1 sides clearly need only be counted to simulation volume, wherein, should by simulation volume, with the corresponding final condition consideration symmetry at the plane of symmetry 32 corresponding edges.

Figure 2 shows that reference fluctuation that boundary surface 15 places of electrolyzer 10 shown in (overlook and see) Fig. 1 occur forms potentiality and distributes, shown in figure, be in two symmetric halves of electrolyzer 10, wherein, Fig. 2 has shown the potentiometric contour that forms potentiality with reference to fluctuation in detail.The outline that has shown equally the negative electrode 12 of electrolyzer 10 in figure.

As can be seen from Figure 2, the reference of electrolyzer 10 fluctuation forms potentiality and comprises a plurality of crests 34, according to quantity that exist, closed potentiometric contour alternately, can from Fig. 2, see the maximum height of crest.

Fig. 3 has shown the vertical view of negative electrode 12 one of them symmetric halves of electrolyzer 10 shown in Fig. 1.Comparison diagram 3 and Fig. 2, each projection 30 in the molding surface of negative electrode 12 is arranged on reference under the crest 34 of fluctuation formation potentiality, overlooks and observes, and crest 34 and projection 30 are substantially superimposed on arranging.Crest 34 in Fig. 2 and projection 30 corresponding in Fig. 3 in numbering 30 and 34 below with identical letter representation, i.e. protruding 30a correspondence crest 34a, other numberings are also like this.

Projection 30 shape adapts with the crest 34 that the reference fluctuation of appointment forms potentiality respectively, wherein, each projection 30 is specified respectively the shape of crest 34 with the geometrical shape of simplifying close to each, for example there is the oval-shaped protruding 34g of being essentially of oval outline and 34j, the protruding 30h of terrace with edge shape, the 34b of half terrace with edge shape, 34c, 34e, 34l, 34m, 34n, 34o, and at 34a and the 34b of 1/4th terrace with edge shapes of negative electrode 12 corner regions.

Fig. 4 has shown the 3D shape that is adapted to form with reference to fluctuation the projection 30 of potentiality by stereo-picture.As can be seen from Figure for placing bus 20(Fig. 1) groove 37 be arranged on the bottom side of negative electrode 12.

The fluctuation that Figure 5 shows that the electrolyzer 10 of the negative electrode 16 with surface process moulding forms the distribution in the boundary surface 15 of potentiality between liquid aluminium lamination 14 and melt layer 16.Fluctuation shown in Fig. 5 is formed to potentiality distribution and distribute and compare with the reference fluctuation formation potentiality shown in Fig. 2, by molding surface, significantly improve the height that fluctuation forms homogeneity or the smoothness of potentiality distribution medium wave peak 34 and reduces crest.Specifically, Fig. 5 demonstrates crest 34, and its maximum has two that be staggeredly placed, closed potentiometric contours.Therefore, form potentiality compare with reference fluctuation, it is much smaller that the maximum fluctuation in boundary surface 15 respective regions forms potentiality.Thus, electrolyzer 10 stability during operation increases greatly, and then longer service life, and the Energy efficiency of electrolyzer 10 is higher.

Fig. 6 and the example that Figure 7 shows that the projection 30 that is specially adapted to electrolyzer 10 molding surfaces of the present invention.Each projection 30 shown in Fig. 6 can be extruded formation by geometry.Fig. 6 a-c has shown respectively the bottom surface 36 of Polygons, ellipse and other shapes, and projection 30 is set out and carried out extrusion moulding by described bottom surface.Extruding vertically z carries out in a direction indicated by the arrow.

Fig. 6 d has shown the terrace with edge shape projection 30 of extruding from bottom surface shown in Fig. 6 a.Vertically the geometry of z extrudes that area reduces gradually along with the increase of height, and the projection 30 therefore obtaining is upwards tapered.The reference axis of area reducing is Z-axis, and this reference axis is set out by the centroid point 38 of bottom surface 36.Projection 30 shown in Fig. 6 d is dwindled and is formed by isotropy, area in all directions vertical with extruding axle same degree towards extruding together with axle is retracted to.Fig. 6 e has shown it is also the projection 30 of extruding from bottom surface 36 shown in Fig. 6 a, but it is reduced into anisotropy, that is, in all directions vertical with extruding direction, area reducing degree is completely different.And the projection 30 shown in Fig. 6 e is the equal of an axle departing from a Small angle along vertical line and the projection extruded.Therefore, shown in Fig. 6 e, the centroid point 38 of the end face 40 of projection 30 is compared in the centroid point 28 of end face 40 shown in Fig. 6 d, with respect to the centroid point 38 occurred level skews of bottom surface 36.

Fig. 6 f and Fig. 6 g have shown respectively the projection 30 of extruding from 36s, oval bottom surface shown in Fig. 6 b, wherein, projection 30 shown in Fig. 6 f is dwindled and is formed by extruding in direction the isotropy of area, and projection shown in Fig. 6 g is dwindled and formed by extruding in direction the anisotropy of area.

Fig. 6 h and Fig. 6 i have shown respectively the projection 30 of extruding from 36s, bottom surface shown in Fig. 6 c, and wherein, projection 30 shown in Fig. 6 h is dwindled and formed by extruding in direction the isotropy of area, and projection shown in Fig. 6 g is dwindled and formed by extruding in direction the anisotropy of area.

Fig. 7 a-i has also shown can be by rotating the example of the projection 30 forming how much to bottom surface 36.Fig. 7 a-c has shown different bottom surface 36, i.e. Polygons bottom surface 30 in Fig. 7 a, the half elliptic bottom surface 30 in Fig. 7 b, the bottom surface 30 of the free shape in Fig. 7 c.A sideline of each bottom surface 36 becomes the turning axle 42 of rotation.

Fig. 7 d and Fig. 7 e have shown respectively by Polygons bottom surface shown in Fig. 7 a and have set out and the projection 30 that forms, wherein, according to Fig. 7 d, rotator is only by rotating to form, according to Fig. 7 e, gained rotator anisotropically dwindles in the direction perpendicular to bottom surface 36 with respect to bottom surface 36.

Fig. 7 f and Fig. 7 g have shown respectively by half elliptic bottom surface shown in Fig. 7 b and have set out and the projection 30 that forms, wherein, in Fig. 7 f, rotator is only by rotating to form, in Fig. 7 g, gained rotator anisotropically dwindles in the direction perpendicular to bottom surface 36 with respect to bottom surface 36 again.

Fig. 7 h and Fig. 7 i have shown respectively by bottom surface shown in Fig. 7 c and have set out and the projection 30 that forms, wherein, in Fig. 7 h, rotator is only by rotating to form, in Fig. 7 i, gained rotator anisotropically dwindles in the direction perpendicular to bottom surface 36 with respect to bottom surface 36 again.

reference numerals list

10 electrolyzers

12 negative electrodes

14 liquid aluminium laminations

15 boundary surfaces

16 melt layer

18 anodes

20 buses

22 electric current outlet lines

24 anode blocks

26 anode trees

28 supply lines

30 projections

32 planes of symmetry

34 crests

36 bottom surfaces

37 grooves

38 centroid points

39 arrows

40 end faces

42 turning axles

X electrolyzer longitudinally

Y electrolyzer laterally

Claims (33)

1. an electrolyzer, the electrolyzer of producing in particular for aluminium, comprise negative electrode (12), be positioned at the liquid aluminium lamination (14) on the end face of described negative electrode (12), be positioned at the melt layer (16) above of described liquid aluminium lamination, and the anode (18) that is positioned at the top of described melt layer (16), wherein, the end face of described negative electrode (12) has the molding surface being formed by two or more projections (30), the molding surface of described negative electrode (12) carries out layout and setting in the following manner: in lip-deep 20 points of described negative electrode (12) end face, have at least two points to be provided with projection (30), these points are positioned at the vertical lower in some regions of the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16), the reference fluctuation formation potentiality being present in described boundary surface (15) is distributed in the crest (34) that occurs having 20 maximums in described region, wherein, with reference to fluctuation form potentiality be defined as do not there is the negative electrode (12) with molding surface but have electrolyzer (10) on period without the reference negative electrode of molding surface appear at the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16) in the fluctuation formation potentiality at a some place, described identical with the negative electrode (12) with molding surface with reference to other structures of negative electrode.

2. an electrolyzer, the electrolyzer of producing in particular for aluminium, comprise negative electrode (12), be positioned at the liquid aluminium lamination (14) on the end face of described negative electrode (12), be positioned at the melt layer (16) above of described liquid aluminium lamination, and the anode (18) that is positioned at the top of described melt layer (16), wherein, the end face of described negative electrode (12) has the molding surface being formed by two or more projections (30), the molding surface of described negative electrode (12) carries out layout and setting in the following manner: in lip-deep 20 points of described negative electrode (12) end face, have at least two points to be provided with projection (30), these points are positioned at the vertical lower in some regions of the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16), the reference fluctuation formation potentiality being present in described boundary surface (15) is distributed in the crest (34) that occurs having 20 maximums in described region, wherein, with reference to fluctuation form potentiality be defined as do not there is the negative electrode (12) with molding surface but have electrolyzer (10) on period without the reference negative electrode of molding surface appear at the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16) in the fluctuation formation potentiality at a some place, described identical with the negative electrode (12) with molding surface with reference to other structures of negative electrode, wherein, describedly with reference to negative electrode, in electrolyzer (10), be in height set to, volume while making volume between described reference electrode and anode (18) of described liquid aluminium lamination (14) and melt layer (16) and electrolyzer (10) have the negative electrode (12) with molding surface is identical.

3. electrolyzer according to claim 1 and 2, it is characterized in that having at least X point to be provided with projection (30) in lip-deep Y point of described negative electrode (12) end face, these points are positioned at the vertical lower in some regions of the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16), the reference fluctuation formation potentiality being present in described boundary surface (15) is distributed in the crest (34) that occurs having Y maximum in described region

Wherein, X=4 and Y=20, preferably, X=6 and Y=20, particularly preferably, X=10 and Y=20, most preferably, X=14 and Y=20, and/or

Wherein, X=2 and Y=10, preferably, X=3 and Y=10, particularly preferably, X=5 and Y=10, most preferably, X=7 and Y=10, and/or

Wherein, X=1 and Y=5, preferably, X=2 and Y=5, particularly preferably, X=3 and Y=5, most preferably, X=4 and Y=5.

4. according to the electrolyzer described at least one claim in claim 1 or 3, it is characterized in that being provided with projection (30) at the lip-deep point of described negative electrode (12) end face place, described point is positioned at the vertical lower in some regions of the boundary surface (15) between liquid aluminium lamination (14) and melt layer (16), being present in reference in boundary surface (15) fluctuation forms potentiality and is distributed in and in described region, occurs crest (34), described at least one, projection has its maximum height at the some place that is arranged in the vertical lower of the point of boundary surface (15) between liquid aluminium layer (14) and melt layer (16), the crest (34) that forms potentiality distribution with reference to fluctuation has maximum value at this some place.

5. electrolyzer according to claim 4, it is characterized in that the some place on described negative electrode (12) top surface is provided with projection (30), described point is arranged on the vertical lower in some regions of boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16), being present in reference in described boundary surface (15) fluctuation forms potentiality and is distributed in and in these regions, occurs crest (34), all described projections have maximum height at the some place that is arranged in the vertical lower of the point of boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16), described each crest (34) distributing with reference to fluctuation formation potentiality has maximum value at these some places.

6. according to the electrolyzer described at least one claim in aforementioned claim, it is at least substantially similar that how much outlines that it is characterized in that overlooking projection (30) described at least one that see and the reference fluctuation of overlooking to see form the geometry outlines of each crest (34) that potentiality distributes.

7. electrolyzer according to claim 6, with reference to fluctuation, to form the geometry outlines of each crest (34) that potentiality distributes at least substantially similar with overlooking see described for how much outlines that it is characterized in that overlooking all projections (30) of seeing.

8. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that overlooking how much outlines of projection (30) described at least one that see and be designed at least in part at least be similar to Polygons and/or oval-shaped shape, wherein, especially described Polygons has 3,4,5 or 6 angles.

9. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that at least one projection (30) has outline, the geometrical shape of outline that the reference fluctuation that is positioned at described projection (30) vertical direction than from the described boundary surface (15) of vertical view from the geometrical shape of the outline of the described projection of vertical view forms the crest (34) that potentiality distributes is simple, wherein, preferably, compare with the outline of described crest (34) from vertical view, the number at the angle having from the outline of the described projection (30) of vertical view still less and/or the number of flex point still less.

10. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that the 3D shape of at least basic and described each crest (34) that forms potentiality distribution with reference to fluctuation of the 3D shape of projection (30) described at least one is similar or consistent.

11. electrolyzers according to claim 10, is characterized in that the 3D shape of all projections (30) is at least substantially similar or consistent with the 3D shape of described each crest (34) distributing with reference to fluctuation potentiality.

12. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that projection (30) has vertically (z) upward-fining 3D shape described at least one.

13. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that vertically (z) looks up, described at least one, to take end face (40) be boundary to projection (30), and the area of the end face of the described projection (30) of seeing from vertical view is less than the area of the bottom surface (36) of the described projection (30) of seeing from vertical view.

14. according to the electrolyzer described at least one claim in aforementioned claim, the 3D shape that it is characterized in that projection (30) described at least one from described projection (30) bottom surface, (rotated and form around the turning axle (42) that limits bottom surface (36) by described bottom surface (36) by 36)s, wherein, preferably, described turning axle (42) is horizontal-extending.

15. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that the 3D shape of projection (30) described at least one from the bottom surface of described projection (30) (36)s by the bottom surface (36) of described projection (30) vertically (z) upwards carry out geometry and extrude and form.

16. electrolyzers according to claim 15, it is characterized in that described at least one projection (30) vertically (z) be upwards tapered.

17. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that described negative electrode (12) comprises two or more cathode blocks, and/or described anode (18) comprises two or more anode blocks (24).

18. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that the distance between described anode (18) and liquid aluminium lamination (14) is 15mm to 45mm, preferably 15mm to 35mm, particularly preferably 15mm to 25mm.

19. according to the electrolyzer described at least one claim in aforementioned claim, it is characterized in that the molding surface of described negative electrode (12) forms irregular at least in one direction.

20. 1 kinds of negative electrodes for aluminium cell, the end face of described negative electrode has a kind of molding surface, and described molding surface has two or more first battens (30) that substantially extend along the first direction (y) of described negative electrode (12) and at least one the second batten (30) that at least the basic edge direction vertical with the first direction (y) of described negative electrode (12) (x) extended.

21. negative electrodes according to claim 20, described in it is characterized in that, at least two the first battens (30) extend along the horizontal direction (y) of described negative electrode approx.

22. according to the negative electrode described in claim 20 or 21, the end face that it is characterized in that described negative electrode (12) sees that from vertical view having one is the outline of rectangle substantially, wherein, at least one place, angle in four angles of the basic outline for rectangle is provided with the projection (30) of a negative electrode (12), wherein, preferably, from vertical view, described projection (30) has an outline being generally triangular.

23. according to the negative electrode described at least one claim in claim 20 to 22, it is characterized in that described negative electrode (12) end face comprises a depression, described depression is seen the shape of at least substantially V-shaped basin from negative electrode (12) cross section, wherein, described at least two the first battens (30) and at least one the second batten (30) are preferably arranged on the surface of the basic depression for V-arrangement.

24. negative electrodes according to claim 23, is characterized in that described Basic Design is that two supporting leg tie points of cross section of the depression of V-arrangement basin see from the cross section of described negative electrode (12) middle that is at least generally arranged at described negative electrode (12).

25. according to the negative electrode described in claim 23 or 24, is recessed at least 75% described in it is characterized in that, and preferably at least 90%, particularly preferably at least 95%, extension on 100% described negative electrode (12) surface most preferably.

26. according to the negative electrode described at least one claim in aforementioned claim 20 to 25, it is characterized in that from the second direction of described negative electrode (12) (x) described at least one second batten (30) is preferably at least generally arranged at the middle portion of described negative electrode (12).

27. according to the negative electrode described at least one claim in aforementioned claim 20 to 26, and the middle portion of the upper limb that it is characterized in that described at least one the first batten (30) from the horizontal direction (y) of described negative electrode (12) and the distance between the top of described V-arrangement basin to described negative electrode (12) increases gradually.

28. 1 kinds of electrolyzers, in particular for producing the electrolyzer of aluminium, comprise according to the negative electrode (12) described at least one claim in claim 20 to 27, be positioned at the liquid aluminium lamination (14) on the end face of described negative electrode (12), be positioned at the melt layer (16) above of described liquid aluminium lamination, and the anode (18) that is positioned at the top of described melt layer (16).

29. electrolyzers according to claim 28, it is characterized in that described anode (18) comprises at least two anode blocks that are set up in parallel (24) and a web member extending between described at least two anode blocks (24), wherein, at least one first batten (30) of described negative electrode (12) is arranged on web member vertical lower between described two anode blocks (24) at least substantially parallel with it.

30. electrolyzers according to claim 29, are arranged on the preferably roughly medially setting of relatively described web member of at least one first batten (30) of described web member vertical lower described in it is characterized in that.

The manufacture method of electrolyzer (10) 31. 1 kinds of electrolyzers (10), that produce in particular for aluminium, described electrolyzer comprises negative electrode (12), be positioned at the liquid aluminium lamination (14) on the end face of described negative electrode (12), be positioned at the melt layer (16) above of described liquid aluminium lamination, and the anode (18) that is positioned at the top of described melt layer (16), wherein said manufacture method comprises the following steps:

-determine the liquid aluminium lamination (14) of present described electrolyzer (10) and the fluctuation of the reference in the boundary surface (15) between melt layer (16) to form potentiality and distribute;

-manufacture the molding surface on described negative electrode (12) end face comprise a plurality of projections (30), wherein, in 20 on described negative electrode (12) top surface, have at least two points to be respectively provided with a projection (30), described point is positioned at the vertical lower in some regions of the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16), is present in reference in described boundary surface (15) fluctuation potentiality and is distributed in and in described region, occurs having 20 crests (34) of high extreme value;

Wherein, with reference to fluctuation potentiality, be defined as having without the reference negative electrode of molding surface rather than appearing at fluctuation formation potentiality at some place in the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16) with electrolyzer (10) on period of the negative electrode (12) of molding surface, described identical with the negative electrode (12) with molding surface with reference to other structures of negative electrode.

The manufacture method of electrolyzer (10) 32. 1 kinds of electrolyzers (10), that produce in particular for aluminium, described electrolyzer comprises a negative electrode (12), be positioned at the liquid aluminium lamination (14) on the end face of described negative electrode (12), be positioned at the melt layer (16) above of described liquid aluminium lamination, and the anode (18) that is positioned at the top of described melt layer (16), wherein said electrolyzer manufacture method comprises the following steps:

-determine the liquid aluminium lamination (14) of present described electrolyzer (10) and the fluctuation of the reference in the boundary surface (15) between melt layer (16) to form potentiality and distribute;

-manufacture the molding surface on described negative electrode (12) end face comprise a plurality of projections (30), wherein, in 20 on described negative electrode (12) top surface, have at least two points to be respectively provided with a projection (30), described point is positioned at the vertical lower in some regions of the boundary surface (15) between described liquid aluminium lamination (14) and melt layer (16), be present in reference in described boundary surface (15) fluctuation potentiality be distributed in described region, occur having 20 the crest (34) of high extreme value occur;

Wherein, with reference to fluctuation potentiality, be defined as and have without the reference negative electrode of molding surface rather than with electrolyzer (10) on period of the negative electrode (12) of molding surface, appear at fluctuation formation potentiality at some place in the boundary surface (15) between described liquid aluminium lamination (10) and melt layer (16), described identical with the negative electrode (12) with molding surface with reference to other structures of negative electrode, wherein, describedly with reference to negative electrode, on the height in described electrolyzer (10), be set to, volume while making volume between described reference electrode and anode (18) of described liquid aluminium lamination (14) and melt layer (16) and described electrolyzer (10) have the negative electrode (12) with molding surface is identical.

33. 1 kinds according to the method described in claim 31 or 32 for the manufacture of according to the purposes of the electrolyzer (10) described at least one claim in aforementioned claim 1 to 19.

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