CELL BOTTOM STRUCTURE OF REDUCTION CELL

STRUCTURE DE FOND D'UNE CELLULE ELECTROLYTIQUE

English Abstract

The present invention discloses a cell bottom structure of a reduction
cell which comprises a reduction cell (1) and a cathode bus (2), wherein
the bottom of the reduction cell (1) is provided with column-shaped
cathode carbon blocks (3) perpendicular to the bottom of the reduction
cell (1), and a lower end of the column-shaped cathode carbon block (3)
is connected to the cathode bus (2). By means of inserting the
column-shaped cathode carbon blocks perpendicular to the bottom of the
reduction cell and connecting the lower end of the column-shaped
cathode carbon block with the cathode bus, such that electrical current
that guided from anode carbon blocks is guided through the molten
aluminum to the column-shaped cathode carbon blocks and is
downwardly guided out, the present invention reduces horizontal
electrical current in the molten aluminum, such that the cathode
extending into the molten aluminum can effectively reduce fluctuations of
the molten aluminum to obtain a stable surface of the molten aluminum,
thereby reducing a polar distance between a cathode and an anode and
lowering cell voltage so as to achieve the object of lowering electricity
consumption.

French Abstract

La présente invention concerne une structure de fond d'une cellule électrolytique comprenant une cellule électrolytique (1) et une barre de distribution cathodique (2). Des blocs de carbone de cathode en colonnes (3) disposés au fond de la cellule électrolytique (1) sont placés perpendiculairement au fond de la cellule électrolytique (1) et les extrémités inférieures des blocs de carbone de cathode en colonnes (3) sont couplées aux barres de distribution cathodiques (2). Du fait de l'insertion perpendiculaire des blocs de carbone de cathode en colonnes au fond de la cellule électrolytique et du couplage des extrémités inférieures des blocs de carbone de cathode en colonnes (3) aux barres de distribution cathodiques, le courant provenant du bloc d'anode est déplacé vers le bas par l'intermédiaire du liquide d'aluminium et des blocs de carbone de cathode en colonnes, ce qui diminue le courant horizontal. La cathode s'étendant dans le liquide d'aluminium peut efficacement réduire la fluctuation du liquide d'aluminium, ce qui permet d'obtenir une surface stable du liquide d'aluminium et de réduire la distance entre l'anode et la cathode. La tension de cellule inférieure ainsi obtenue aura à son tour pour effet de réduire la consommation d'énergie.

Claims

CLAIMS
1. A cell bottom structure of a reduction cell comprising a reduction cell
and
a cathode bus, wherein the bottom of the reduction cell is provided with
column-shaped
cathode carbon blocks perpendicular to the bottom of the reduction cell, and a
lower end
of the column-shaped cathode carbon block is connected to the cathode bus.
2. The cell bottom structure of a reduction cell according to claim 1,
wherein
the column-shaped cathode carbon blocks are located below anode carbon blocks.
3. The cell bottom structure of a reduction cell according to claim 2,
wherein
there is/are 1-4 column-shaped cathode carbon blocks provided below each anode

carbon block.
4. The cell bottom structure of a reduction cell according to claim 1,
wherein
the column-shaped cathode carbon blocks extend a length of 5-200mm into molten

aluminum of the reduction cell.
5. The cell bottom structure of a reduction cell according to claim 1,
wherein
the column-shaped cathode carbon blocks are connected with the cathode bus
through
bolts.
6. The cell bottom structure of a reduction cell according to claim 1,
wherein
the column-shaped cathode carbon blocks have a shape of quadrangular prism or
quadrangular prism with steps.
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Description

CA 02785868 2013-10-18
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Cell bottom Structure of Reduction Cell
Field of the Invention
The present invention relates to a cell bottom structure of a reduction
cell, pertaining to the technical field of aluminum reduction cell.
Background of the Invention
In the production of a prebaked reduction cell, most of the aluminum
reduction cells select a planar cell bottom with cathode carbon blocks
placed horizontally, into which an electric current enters from an upper
anode and guided out of a lateral portion of the cell to form a turn of
900, thereby forming a relatively large horizontal electric current at a
layer of molten aluminum. The horizontal electric current tends to cause
the molten aluminum to form an eddy flow under the action of magnetic
field to generate a relatively large wave crest, such that on one hand, it
influences the stable operation of the reduction cell, and on the other
hand, in order to prevent a short circuit due to a wave crest of the molten
aluminum scours to a anode, a polar distance of the cathode and the
anode must be increased, resulting a rise in cell voltage and an increase in
electricity consumption. At the same time, the cathode carbon blocks are
placed horizontally, this. results in a complicated structure of a cell
housing of .the reduction cell since thermal expansion and sodium
absorption expansion render complicated force conditions for the cell
housing and its periphery. In addition, failure of introducing electricity
and aggregation of lateral output electric current towards cell edges
impact the safety of cell ledges of the reduction cell, resulting a large
amount of steel used for the cell ledges.
Summary of the Invention
The technical problem to be solved by the present invention, in some
embodiments, is to provide a cell bottom structure of a reduction cell, which
can
reduce
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horizontal electrical current in a layer of molten aluminum, eliminate
stresses on a cell
housing generated due to cathode expansion, simply the structure of the cell
housing,
reducing polar distance of the reduction cell and cell voltage, alleviate a
construction
cost of the cell housing and overcome shortages in the prior art.
According to one aspect of the present invention, there is provided a cell
bottom structure of a reduction cell comprising a reduction cell and a cathode
bus,
wherein the bottom of the reduction cell is provided with column-shaped
cathode carbon
blocks perpendicular to the bottom of the reduction cell, and a lower end of
the column-
shaped cathode carbon block is connected to the cathode bus.
In some embodiments, the column-shaped cathode carbon blocks are
located below anode carbon blocks.
In some embodiments, there is/are 1-4 column-shaped cathode carbon
blocks provided below each anode carbon block.
In some embodiments, the column-shaped cathode carbon blocks extend a
length of 5-200mm into molten aluminum of the reduction cell.
In some embodiments, the column-shaped cathode carbon blocks are
connected with the cathode bus through bolts.
In some embodiments, the column-shaped cathode carbon blocks have a
shape of quadrangular prism or quadrangular prism with steps.
By comparison with the prior art, by means of inserting the column-
shaped cathode carbon blocks perpendicular to the bottom of the reduction cell
and
connecting the lower end of the column-shaped cathode carbon block with the
cathode
bus, such that electrical current that guided from anode carbon blocks is
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CA 02785868 2013-10-18
73140-34
guided through the molten aluminum to the column-shaped cathode carbon blocks
and is downwardly guided out, the present invention in some embodiments may
reduce horizontal electrical current in the molten aluminum, such that the
cathode
extending into the molten aluminum can effectively reduce fluctuations of the
molten aluminum to obtain a stable surface of the molten aluminum, thereby
reducing a polar distance of a cathode and an anode and lowering cell voltage
so
as to achieve the object of lowering electricity consumption. According to a
number of tests by the applicant, a cathode/anode polar distance can reduce
100-250mm, a voltage drop of the cathode can reduce 100-200mv, a cell voltage
can reduce 400-850mv, and an effect of saving 1200-2500kwh/t-Al may be
achieved. In some embodiments, the column-shaped cathode carbon blocks have
a shape of quadrangular prism or quadrangular prism with steps, and segment-
splicing arrangement and cell bottom placement thereof eliminate stresses
exerted
on the cell housing by the thermal expansion and sodium absorption expansion,
enabling a simplification of the cell housing design and the material used.
According to the statistics of the test examination, the steel amount used for
the
cell bottom can be saved 70%, the lifespan of the cell can increase 500 days,
allowing the impact of electrolyte deposition on the cell bottom electric
conduction to be minimized. In some embodiments, the column-shaped cathode
carbon blocks are located below the anode carbon blocks, so as to facilitate
the
electric current to be vertically guided from the anode carbon blocks. In some

embodiments, there is/are 1-4 column-shaped cathode carbon blocks provided
below each of the anode carbon blocks, and the column-shaped cathode carbon
blocks extend a length of 5-200mm into the molten aluminum of the reduction
cell, wherein the specific number and positions thereof are determined in
accordance with the reduction cell capacity and the anode dimension. In some
embodiments, the column-shaped cathode carbon blocks are interconnected with
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CA 02785868 2013-10-18
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the cathode bus through bolts, wherein the cross-sectional dimension of the
bus
and the number of the bolts are determined in accordance with the magnitude of

current. Some embodiments of the present invention can also effectively
inhibit
eddy flow of molten aluminum, simplify the cell housing structure, decrease
initial construction investment, improve current distribution, extend lifespan
of
the reduction cell, and has a very good popularizing value.
Brief Description of the Drawings
Fig.1 is a schematic view of the configuration of the present
invention;
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Fig.2 is an A-A view of Fig.l.
Detailed Description of the Invention
Embodiment 1: as shown in Figs. 1 and 2, in a design of a reduction
cell, cathodes are made as column-shaped cathode carbon blocks 3 which
have a shape of quadrangular prism or quadrangular prism with steps. The
column-shaped cathode carbon blocks 3 are placed perpendicular to a cell
bottom of the reduction cell 1 when placing the column-shaped cathode
carbon blocks 3. Upper ends of the perpendicularly placed column-shaped
cathode carbon blocks 3 extend a length of 5,--200mm into molten
aluminum in the reduction cell I and lower ends of the column-shaped
cathode carbon blocks 3 are connected with a cathode bus 2 through bolts.
When placing and mounting the column-shaped cathode carbon blocks 3
perpendicular to the cell bottom of the reduction cell, the column-shaped
cathode carbon blocks 3 are mounted below anode carbon blocks 4. There
is/are 1-4 column-shaped cathode carbon blocks 3 provided below each
anode carbon block 4, wherein the specific number and positions thereof
are determined in accordance with the reduction cell capacity and the
anode dimension. Besides, the reduction cell I arranged according to the
present invention can eliminate the cathode steel rod and steel cell
housing in the cathode carbon blocks. The reduction cell employs heat
insulation materials and corrosion resistant materials to design a lava pool,
thus it is only necessary to consider self expansion of the materials during
the manufacture, enabling the structure of the reduction cell to be
simplified to a great extent. The design of the reduction cell is based on a
low cell voltage, thereby decreasing the amount of heat dissipation.
According to a test examination, the reduction cell produced in
accordance with the present invention can save 10%-20% of energy
compared to conventional reduction cells.
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Representative Drawing