U.S. patent application number 12/994728 was filed with the patent office on 2011-03-24 for 400ka high energy efficiency reduction pot.
This patent application is currently assigned to Northeastern University Engineering and Research Institute Co., Ltd.. Invention is credited to Hui Dong, Yongjun Guan, Jingxiong Liu, Dingxiong Lv, Shaoxian Ma, Jihong Mao, Yu Mao, Xiquan Qi, Dequan Wang, Youwei Wu.
Application Number | 20110067999 12/994728 |
Document ID | / |
Family ID | 40013105 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110067999 |
Kind Code |
A1 |
Lv; Dingxiong ; et
al. |
March 24, 2011 |
400kA HIGH ENERGY EFFICIENCY REDUCTION POT
Abstract
A 400 kA high energy efficiency reduction pot, comprising: anode
carbon blocks, anode busbars, crust breaking and feeding device,
anode lifting device, girders and pillars, pot hooding and
exhausting system, cathode busbar arrangement structure, cathode
carbon blocks, cathode lining structure and cathode pot shell, the
pot is characterized in that: 1) superstructure and portal-type
pillars are supported by pipe truss girders structure; 2) anode
carbon block has eight steel stubs to be configured in a
symmetrical mode; 3) the superstructure has 24 double-anode
assemblies or 48 single-anode assemblies, six alumina feeding
points, and two fluoride salt feeding points; 4) sub-section fume
collecting and exhausting system is installed between a horizontal
hood plate and a feeding hopper; 5) a device for sealing the anode
rod by means a negative pressure suction is provided; 6) a new
lining structure of holding heat on bottom, dispersing heat from
side, and adding expansion layer at the cathode end have been
designed based on the simulation of the electric field and thermal
field; 7) the cathode busbars adopt a non-symmetrical
configuration, and six power incoming points on the long side of
the pot is provided; and 8) rectangular pipe truss girders are used
as both air-supply pipeline above the pot and a silencer for tailed
air from the crust breaking and feeding cylinder. The present
invention has markedly energy-saving and emission reduction
effect.
Inventors: |
Lv; Dingxiong; (Liaoning,
CN) ; Wu; Youwei; (Liaoning, CN) ; Qi;
Xiquan; (Liaoning, CN) ; Ma; Shaoxian;
(Liaoning, CN) ; Mao; Jihong; (Liaoning, CN)
; Dong; Hui; (Liaoning, CN) ; Wang; Dequan;
(Liaoning, CN) ; Liu; Jingxiong; (Liaoning,
CN) ; Mao; Yu; (Liaoning, CN) ; Guan;
Yongjun; (Liaoning, CN) |
Assignee: |
Northeastern University Engineering
and Research Institute Co., Ltd.
Shenyang City
CN
|
Family ID: |
40013105 |
Appl. No.: |
12/994728 |
Filed: |
May 25, 2009 |
PCT Filed: |
May 25, 2009 |
PCT NO: |
PCT/CN2009/000568 |
371 Date: |
November 24, 2010 |
Current U.S.
Class: |
204/225 |
Current CPC
Class: |
C25C 3/16 20130101; C25C
3/10 20130101; C25C 3/08 20130101; C25C 3/22 20130101; C25C 3/125
20130101 |
Class at
Publication: |
204/225 |
International
Class: |
C25C 3/08 20060101
C25C003/08; C25C 3/10 20060101 C25C003/10 |
Foreign Application Data
Date |
Code |
Application Number |
May 27, 2008 |
CN |
200810011587.0 |
Dec 27, 2008 |
CN |
200810186879.8 |
Claims
1. A 400 kA high energy efficiency reduction pot, comprising: anode
carbon blocks, anode busbars, crust breaking and feeding device,
anode lifting device, girders and pillars, pot hooding and
exhausting system, cathode busbar arrangement structure, cathode
carbon blocks, cathode lining structure and cathode pot shell, the
pot is characterized in that: 1) superstructure and portal-type
pillars are supported by pipe truss girders structure; 2) anode
carbon block has eight steel stubs to be configured in a
symmetrical mode; 3) the superstructure has 24 double-anode
assemblies or 48 single-anode assemblies, six alumina feeding
points, and two fluoride salt feeding points; 4) sub-section fume
collecting and exhausting system is installed between a horizontal
hood plate and a feeding hopper; 5) a device for sealing the anode
rod by means a negative pressure suction is provided; 6) a new
lining structure of holding heat on bottom, dispersing heat from
side, and adding expansion layer at the cathode end have been
designed based on the simulation of the electric field and thermal
field; 7) the cathode busbars adopt a non-symmetrical
configuration, and six power incoming points on the long side of
the pot is provided; and 8) rectangular pipe truss girders are used
as both air-supply pipeline above the pot and a silencer for tailed
air from the crust breaking and feeding cylinder.
2. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the pipe truss girder structure comprises a
connecting beam and crane support provided between two truss
girders, characterized in that: the truss girder has the connecting
beam as the top thereof and is comprised of the portal-type
pillars, upper chords, lower chords, straight web members, and
diagonal web members, all of which take the form of rectangular
steel pipes; wherein 1) the straight web members are distributed at
a certain space between the upper chords and the lower chords; 2)
the inclined chords are placed between the upper chords and the
lower chords, at both sides of the straight web members; 3) the
straight web members and the inclined chords provided at both sides
of the straight web members are arranged to have a umbrella shape
or inverted umbrella shape in turn; and 4) the connecting beam is
positioned on the tops of the straight web members and is at the
same vertical plane with the upper chords.
3. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the anode carbon block assembly has eight
symmetrical steel stubs comprising cross beams and stubs,
characterized in that: the cross beam is comprised of two main
cross beams, two diagonal cross beams, and four small cross beams,
wherein: 1) main cross beams and diagonal cross beams are connected
in a transverse X-shape; 2) the middle portion of each small cross
beam is vertically connected to ends of the main cross beams; 3)
both ends of each small cross beam are curved downwards to be
connected to the stubs, and the bottom of the stubs is fixed on the
carbon block; and 4) a central portion where the two diagonal cross
beams are intercrossed with each other is upwardly connected to the
anode rod.
4. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said new anode arrangement scheme comprises
aluminum reduction pot cavity, anode carbon blocks, and feeding
points, characterized in that: 1) all the feeding points are
disposed in the position where the four anode carbon block
assemblies converge; 2) the gaps between carbon blocks of two
adjacent anode assemblies at the feeding points is widened while
the gaps between carbon blocks of two adjacent anode assemblies at
the non-feeding points is narrowed; and 3) four corners of the
anode carbon blocks at the feeding points are cut off to widen the
space of the feeding points.
5. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the sub-section fume collecting and
exhausting system comprises pot fume flue, a main flue, and a
control valve, characterized in that: 1) the flue is disposed
inside an interlayer between the horizontal hood plate and the
feeding hopper, the lower portion of the feeding hopper is
fabricated into V-shaped configuration, instead of welding to the
plate girder; 2) the flue is divided into two parallel branch fume
pipes and disposed respectively inside the left and right
interlayers between the horizontal hood plate and the feeding
hopper of the aluminum reduction pot 3) the two branch fume pipes
each further comprises front air inlet and rear air inlet; 4) the
main flue to which the two branch fume pipes are led is provided
with the control valve.
6. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said device for sealing the anode rod by use of a
negative pressure suction is provided, the device comprises lateral
plate, front end plate, and top plate, characterized in that: the
device is a cavity formed by the two lateral plates, top plate, and
front end plate and configured to surround around three sides of
the anode rod, wherein 1) a grating structure is adopted for the
three surrounded sides of the anode rod at the front end of the
cavity device; 2) rear end of the cavity is welded to the web beam
and communicated to the horizontal flue; and 3) the cavity device
is positioned over the horizontal hood plate which is used as a
bottom plate.
7. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said new lining structure is designed on basis of
simulation of the electric field and thermal field, and the lining
structure comprises cathode carbon blocks, cathode steel bar, and
bottom refractory material layer, characterized in that: 1) the
cathode steel bar is located in the pot shell, and a portion of the
steel bar exposed out of the cathode carbon blocks is clamped by a
U-shaped metal plate, and then tamped with the refractory castable;
2) the cathode steel bar is wrapped with the refractory insulating
paper, and, is filled with steel bar paste; 3) the middle bottom of
the cathode carbon is provided with granular refractory material
while both ends thereof are provided with refractory bricks; and 4)
a straight edge paste structure, instead of an arc edge paste
structure, is provided between the cathode carbon blocks and the
side wall silicon carbide bricks.
8. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the cathode busbars adopt non-symmetrical
configuration and power incoming from six-point on long side of the
pot, the cathode busbars comprise a busbar on power incoming side;
a busbar on outgoing side, a cathode flexible busbar on power
incoming side, a cathode flexible busbar on outgoing side, a pot
bottom busbar; and riser busbar, characterized in that: 1) the
local compensation busbar is further provided, the local
compensation busbar enters the bottom of the pot, and goes out
along of the end of the aluminum reduction pot, then, is lifted to
a certain height; and 2) 56 cathode flexible busbars and 6 riser
busbars are used to supply power for the aluminum reduction pot,
the number of the cathode flexible busbars to be connected to the 6
riser busbars is 10: 9: 9: 9: 9: 10, respectively.
9. The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the rectangular pipe truss girder is also
used as both the air-supply pipeline and a silencer for tailed air
from the crust breaking and feeding cylinder, comprises a
compressed air pipeline, a crust breaking cylinder, a feeding
cylinder, and aluminum tapping cylinder, characterized in that: 1)
the compressed air pipeline is connected to the rectangular steel
pipe of the truss in the X direction via an one-way air inlet
valve; 2) the rectangular steel pipe of the truss in the X
direction is connected to the air inlet pipes of the crust breaking
cylinder, the feeding cylinder, and the aluminum tapping cylinder
via an electromagnetic control valve; and 3) the tailed air
exhausting pipes of the crust breaking cylinder, the feeding
cylinder, and the aluminum tapping cylinder are connected to the
rectangular steel pipes in the X direction or in the Y direction,
via the electromagnetic control valve.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a technical field of
aluminum electrolysis, particularly, to a structure of prebaked
anode aluminum reduction pot, which is a kernel apparatus employed
in a molten bath method for producing aluminum. More particularly,
the present invention relates to an ultra-large capacity 400 kA
high energy efficiency reduction pot.
[0003] 2. Description of the Related Art
[0004] It has been known that the conventional prebaked anode
aluminum reduction pot is mainly consisting of two portions, i.e.,
a superstructure and a cathode structure. The superstructure
comprises anode carbon blocks assemblies, anode busbars, crust
breaking and feeding device, anode lifting mechanism, girders,
portal-type pillars, and pot fume hooding system. The cathode
structure comprises cathode carbon blocks, pot lining structure and
pot shell structure. There are several problems in the conventional
prebaked anode aluminum reduction pot. In order to overcome these
problems, Chinese Patent No. CN200510047245.0 discloses a new
design of the large capacity prebaked anode aluminum reduction pot.
This invention is primarily directed to construction and operation
of 160 KA.about.360 KA prebaked anode aluminum reduction pot.
[0005] Nowadays, with capacity increasing of the prebaked anode
aluminum reduction pot, it encounters new problems including
magnetic fluid stability, cathode structure, superstructure of the
reduction pot, and effective hooding of pot fume. Thus, the skilled
in the art should take serious considerations on these matters.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an object of the present invention to
provide a new solution which alleviates the conflicts due to the
increased capacity of the pot, such as the increased difficulties
of optimized arrangement of cathode busbar, the increased energy
consumption and the increased discharge of pot fume, in a
ultra-large capacity 400 kA high energy efficiency reduction pot.
Hereby, the new-type 400 kA high energy efficiency reduction pot
has been presented after carrying out the improvements on the above
large capacity prebaked anode aluminum reduction pot.
[0007] A 400 kA high energy efficiency reduction pot, comprising:
anode carbon blocks, anode busbars, crust breaking and feeding
device, anode lifting device, girders and pillars, pot hooding and
exhausting system, cathode busbar arrangement structure, cathode
carbon blocks, cathode lining structure and cathode pot shell, the
pot is characterized in that:
[0008] 1) superstructure and portal-type pillars are supported by
pipe truss girders structure;
[0009] 2) anode carbon block has eight steel stubs to be configured
in a symmetrical mode;
[0010] 3) the superstructure has 24 double-anode assemblies or 48
single-anode assemblies, six alumina feeding points, and two
fluoride salt feeding points;
[0011] 4) sub-section fume collecting and exhausting system is
installed between a horizontal hood plate and a feeding hopper;
[0012] 5) a device for sealing the anode rod by means a negative
pressure suction is provided;
[0013] 6) a new lining structure of holding heat on bottom,
dispersing heat from side, and adding expansion layer at the
cathode end have been designed based on the simulation of the
electric field and thermal field;
[0014] 7) the cathode busbars adopt a non-symmetrical
configuration, and six power incoming points on the long side of
the pot is provided; and
[0015] 8) rectangular pipe truss girders are used as both
air-supply pipeline above the pot and a silencer for tailed air
from the crust breaking and feeding cylinder.
[0016] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the pipe truss girder structure comprises a
connecting beam and crane support provided between two truss
girders, characterized in that:
[0017] the truss girder has the connecting beam as the top thereof
and is comprised of the portal-type pillars, upper chords, lower
chords, straight web members, and diagonal web members, all of
which take the form of rectangular steel pipes; wherein
[0018] 1) the straight web members are distributed at a certain
space between the upper chords and the lower chords;
[0019] 2) the inclined chords are placed between the upper chords
and the lower chords, at both sides of the straight web
members;
[0020] 3) the straight web members and the inclined chords provided
at both sides of the straight web members are arranged to have a
umbrella shape or inverted umbrella shape in turn; and
[0021] 4) the connecting beam is positioned on the tops of the
straight web members and is at the same vertical plane with the
upper chords.
[0022] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the anode carbon block assembly has eight
symmetrical steel stubs comprising cross beams and stubs,
characterized in that: the cross beam is comprised of two main
cross beams, two diagonal cross beams, and four small cross beams,
wherein:
[0023] 1) main cross beams and diagonal cross beams are connected
in a transverse X-shape;
[0024] 2) the middle portion of each small cross beam is vertically
connected to ends of the main cross beams;
[0025] 3) both ends of each small cross beam are curved downwards
to be connected to the stubs, and the bottom of the stubs is fixed
on the carbon block; and
[0026] 4) a central portion where the two diagonal cross beams are
intercrossed with each other is upwardly connected to the anode
rod.
[0027] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said new anode arrangement scheme comprises
aluminum reduction pot cavity, anode carbon blocks, and feeding
points, characterized in that:
[0028] 1) all the feeding points are disposed in the position where
the four anode carbon block assemblies converge;
[0029] 2) the gaps between carbon blocks of two adjacent anode
assemblies at the feeding points is widened while the gaps between
carbon blocks of two adjacent anode assemblies at the non-feeding
points is narrowed; and
[0030] 3) four corners of the anode carbon blocks at the feeding
points are cut off to widen the space of the feeding points.
[0031] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the sub-section fume collecting and
exhausting system comprises pot fume flue, a main flue, and a
control valve, characterized in that:
[0032] 1) the flue is disposed inside an interlayer between the
horizontal hood plate and the feeding hopper, the lower portion of
the feeding hopper is fabricated into V-shaped configuration,
instead of welding to the plate girder;
[0033] 2) the flue is divided into two parallel branch fume pipes
and disposed respectively inside the left and right interlayers
between the horizontal hood plate and the feeding hopper of the
aluminum reduction pot
[0034] 3) the two branch fume pipes each further comprises front
air inlet and rear air inlet;
[0035] 4) the main flue to which the two branch fume pipes are led
is provided with the control valve.
[0036] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said device for sealing the anode rod by use of a
negative pressure suction is provided, the device comprises lateral
plate, front end plate, and top plate, characterized in that: the
device is a cavity formed by the two lateral plates, top plate, and
front end plate and configured to surround around three sides of
the anode rod, wherein
[0037] 1) a grating structure is adopted for the three surrounded
sides of the anode rod at the front end of the cavity device;
[0038] 2) rear end of the cavity is welded to the web beam and
communicated to the horizontal flue; and
[0039] 3) the cavity device is positioned over the horizontal hood
plate which is used as a bottom plate.
[0040] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said new lining structure is designed on basis of
simulation of the electric field and thermal field, and the lining
structure comprises cathode carbon blocks, cathode steel bar, and
bottom refractory material layer, characterized in that:
[0041] 1) the cathode steel bar is located in the pot shell, and a
portion of the steel bar exposed out of the cathode carbon blocks
is clamped by a U-shaped metal plate, and then tamped with the
refractory castable;
[0042] 2) the cathode steel bar is wrapped with the refractory
insulating paper, and, is filled with steel bar paste;
[0043] 3) the middle bottom of the cathode carbon is provided with
granular refractory material while both ends thereof are provided
with refractory bricks; and
[0044] 4) a straight edge paste structure, instead of an arc edge
paste structure, is provided between the cathode carbon blocks and
the side wall silicon carbide bricks.
[0045] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the cathode busbars adopt non-symmetrical
configuration and power incoming from six-point on long side of the
pot, the cathode busbars comprise a busbar on power incoming side;
a busbar on outgoing side, a cathode flexible busbar on power
incoming side, a cathode flexible busbar on outgoing side, a pot
bottom busbar; and riser busbar, characterized in that:
[0046] 1) the local compensation busbar is further provided, the
local compensation busbar enters the bottom of the pot, and goes
out along of the end of the aluminum reduction pot, then, is lifted
to a certain height; and
[0047] 2) 56 cathode flexible busbars and 6 riser busbars are used
to supply power for the aluminum reduction pot, the number of the
cathode flexible busbars to be connected to the 6 riser busbars is
10: 9: 9: 9: 9: 10, respectively.
[0048] The 400 kA high energy efficiency reduction pot according to
claim 1, wherein said the rectangular pipe truss girder is also
used as both the air-supply pipeline and a silencer for tailed air
from the crust breaking and feeding cylinder, comprises a
compressed air pipeline, a crust breaking cylinder, a feeding
cylinder, and aluminum tapping cylinder, characterized in that:
[0049] 1) the compressed air pipeline is connected to the
rectangular steel pipe of the truss in the X direction via an
one-way air inlet valve;
[0050] 2) the rectangular steel pipe of the truss in the X
direction is connected to the air inlet pipes of the crust breaking
cylinder, the feeding cylinder, and the aluminum tapping cylinder
via an electromagnetic control valve; and
[0051] 3) the tailed air exhausting pipes of the crust breaking
cylinder, the feeding cylinder, and the aluminum tapping cylinder
are connected to the rectangular steel pipes in the X direction or
in the Y direction, via the electromagnetic control valve.
[0052] Compared with the present representative 300 kA family
prebaked anode aluminum reduction pot, the 400 kA high energy
efficiency reduction pot according to the present invention at
least has following advantages:
[0053] 1) The cathode busbars have more economic and safer
arrangement, and there is a much more uniform distribution of the
current. Due to the adoption of the non-symmetrical configuration
of cathode busbar around the pot and six-point power incoming from
the long side of the pot, the impacts of the adjacent aluminum
reduction pots and the busbar currents of the adjacent potroom to
the magnetic field distribution are compensated, the requirements
for the stability of the magnetic fluid of the aluminum reduction
pot are satisfied; the phase difference of the equal voltage drop
among these branches are minimized, and, the phase difference of
the equal voltage drop on the power incoming and outgoing sides of
each branch are minimized, so that the security during baking
period of the aluminum reduction pot is ensured; and, the
consumption of busbars is the lowest under the condition that the
busbar voltage drop is equal.
[0054] 2) The lining structure design of the aluminum reduction pot
is accorded with the principle of enhancing thermal insulation on
the pot bottom and improving heat dissipation at the pot sides, to
ensure different isothermal lines exist in the correspond lining
refractory thermal layer, so as to improve the operation of the
aluminum reduction pot and prolong its service life.
[0055] 3) There is an optimized steel structure design for the
aluminum reduction pot. Particularly, the aluminum reduction pot
adopts a boat-type cradle with single rib structure and a pipe
truss girder superstructure. Thus, the steel consumption and the
processing difficulty are greatly reduced.
[0056] 4) There is a more optimized arrangement of the feeding
point position. Particularly, the new anode carbon blocks
arrangement, including six alumina feeding points and two fluoride
salt feeding points, is adopted, such that, the gaps among the
carbon blocks are narrowed, while the feeding space is widened
suitably, and the effective work area of the anode are added.
Therefore, not only the energy consumption is reduced, but also the
production is increased.
[0057] 5) There is an optimized fume collecting system for the
aluminum reduction pot. Particularly, this system eliminates the
air leaking due to the installation of the crust breaking and
feeding device, by effectively using negative pressure caused by
the temperature difference in the pot hood. Therefore, the
uniformity of the negative pressure distribution in the hood and
the fume collecting efficiency from the flue of the aluminum
reduction pot are greatly improved, and, the thermal energy
utilization rate of the aluminum reduction pot is also increased to
some extents.
[0058] In all, compared with the conventional 300 kA family
pre-baked anode aluminum reduction pot, the 400 kA high energy
efficiency reduction pot according to the present invention has
markedly energy-saving and emission reduction effect, and also, it
has great economic benefits and well spreading value.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] These and/or other structures and advantages of the 400 kA
high energy efficiency reduction pot of the invention will become
apparent and more readily appreciated from the following
description of the embodiments, taken in conjunction with the
accompanying drawings of which:
[0060] FIG. 1 is a general structure front view of a pre-baked
anode aluminum reduction pot according to the present
invention;
[0061] FIG. 2 is a general structure side view of the aluminum
reduction pot according to the present invention;
[0062] FIG. 3 is a structural schematic view of a pipe truss girder
according to the present invention;
[0063] FIG. 4 is a structural schematic view of 8 steel stubs of
anode according to the to present invention, FIG. 4A is a
stereogram view of the steel stubs, and, FIG. 4B is schematic view
showing the steel stubs are in a assembled state;
[0064] FIG. 5 is a schematic view of an anode arrangement of the
aluminum reduction pot according to the present invention;
[0065] FIG. 6 is a structural schematic view of a sub-section fume
collecting and exhausting system, FIG. 6A is a front view of the
system, and, FIG. 6B is a plan view of the arrangement of a
flue;
[0066] FIG. 7 is a structural schematic view of a sealing device
for anode rod according to the present invention, FIG. 7A is a plan
projection view of the sealing device, and, FIG. 7B is a sectional
view along line B-B of the FIG. 7;
[0067] FIG. 8 is a horizontal structure schematic view of a lining
of the aluminum reduction pot according to the present
invention;
[0068] FIG. 9 is a structure schematic view of a cathode busbar
arrangement of the aluminum reduction pot according to the present
invention, FIG. 9A is a elevation of the cathode busbar
arrangement, and, FIG. 9B is a plan schematic view of the cathode
busbar arrangement; and
[0069] FIG. 10 is a schematic view of the pipe truss gird provided
at the superstructure of the aluminum reduction pot, which is used
as an air supply pipeline and a silencer for tailed air from the
crust breaking and feeding cylinder.
[0070] In the figures, the following reference numeral designates
the following component: [0071] 1. bottom beam; 2. boat-type cradle
pot shell with single rib; 3. lining; 4. pillar; 5. anode busbar;
6. anode clamp; 7. anode lifting mechanism; 8. crust breaking and
feeding device; 9. anode carbon block; 10. cathode carbon block;
11. pot cover plate; 12. main flue; 13. portal-type pillars; 14.
lower chord; 15. upper chords; 16. diagonal web member; 17.
straight web member; 18. crane supporter; 19. connecting beam; 20.
main cross beam; 21. small cross beam; 22. cant beam; 23. stub; 24.
anode rod; 25. aluminum reduction pot cavity; 26. feeding point;
27. gap between anodes at feeding point; 28. gap between anodes at
non-feeding point; 29. centre gap; 30. feeding hopper; 31. U-shaped
flue steel plate; 32. flue branch pipe; 33. horizontal hood plate;
34. anode balance busbar; 35. flue manifold; 36. control valve; 37.
lateral plate; 38. front end plate; 39. top plate; 40. granular
material; 41. thermal baffle; 42. high temperature resistance
thermal baffle; 43. heat insulation brick; 44. bath corrosion
resistance brick; 45. heat insulation felt; 46. U-shaped metal
plate; 47. refractory castable; 48. silicon carbide brick; 49. arc
side paste; 50. refractory insulating paper; 51. cathode steel bar;
52. steel bar paste; 53. power incoming side busbar; 54. end bypass
busbar; 55. pot bottom busbar; 56. local compensation busbar; 57.
power outgoing side busbar; 58. riser busbar; 59. flexible busbar
on the power incoming side; 60. flexible busbar on the power
outgoing side; 61. short-circuit busbar; 62. crust breaking
cylinder; 63. feeding cylinder; 64. blast pipe for crust breaking
cylinder; 65. return air pipe of crust breaking cylinder; 66. blast
pipe of feeding cylinder; 67. return air pipe of the feeding
cylinder; 68. backblowing air pipe; 69. compressed air pipe; 70.
one-way control valve; 71. cylinder tailed air exhausting pipe; 72.
manual control valve.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0072] These and/or other structures and advantages of the 400 kA
high energy efficiency reduction pot according to the present
invention will become apparent and more readily appreciated from
the following description of the embodiments, taken in conjunction
with the accompanying drawings.
[0073] According to the present invention, the superstructure of
the 400 kA high energy efficiency reduction pot includes anode
carbon block assembly 9, anode busbars 5, crust breaking and
feeding device 8, an anode lifting device 7, and pillar 4, a
subsection fume collecting and exhausting system consisting of pot
cover plate 11, main flue 12 and flue branch pipe 32. The cathode
structure comprises cathode carbon blocks 10, a lining structure,
and a pot shell structure.
[0074] With reference to FIGS. 1 and 2, the 400 kA high energy
efficiency reduction pot is taken as an example for purpose of
detailed description of the present invention. As a matter of fact,
the present invention can also be applicable to the ultra-large
capacity 400 kA.about.550-kA family high energy efficiency
reduction pot.
[0075] 1. The Superstructure of The Aluminum Reduction Pot
[0076] 1) Girder and Pillar
[0077] As shown in FIG. 3, the upper chords 15 and the lower chords
14 employ rectangular steel pipes of 200 mm (the length).times.200
mm (the width).times.10 mm (the thickness); and, the straight web
members 17 and the diagonal web members 16 employ rectangular steel
pipes of 150 mm (the length).times.150 mm (the width).times.8 mm
(the thickness). The straight web members 17 are disposed at a
certain space between the upper chords 15 and the lower chords 14,
and they are joined together by welding, respectively. That is to
say, the straight web members and the inclined chords provided at
both sides of the straight web members are arranged in turn. After
the assembly of the two truss girders, connecting beams 19 are
mounted at the upper chords 15 of the two truss girders, at the top
of the straight web members 17 along a direction perpendicular to
the truss girders. Further, the connecting beams 19 are
respectively connected to the upper chords 16 of the truss girders
by welding. Then, portal-type pillars 13 are provided at both ends
of the truss girders in the longitudinal direction of the aluminum
reduction pot The portal-type pillars 13 empoly rectangular steel
pipes of 250 mm (the length).times.250 mm (the width).times.12 mm
(the thickness). Supporters 18 for the crane are welded below the
connecting beams 19 and over the straight web members 17. Each
crane supporter is provided for one straight web member,
respectively. The crane supporter is made by channel steel, such as
No. 20 according to the Chinese national standard. In this way, the
pipe truss girder assembly of the superstructure of the aluminum
reduction pot is completed.
[0078] In an example, the 400 kA high energy efficiency reduction
pot has the total length of 19184 mm and the total height of 6200
mm.
[0079] 2) Anode Carbon Blocks Assembly
[0080] The anode carbon blocks assembly comprises anode rod 24,
eight steel stubs, and two carbon blocks 9.
[0081] As shown in FIG. 4, the eight steel stubs, two main cross
beams 20, and two cant beams 22 are combined together into a
horizontal X-shaped structure. both ends of each main cross beam 20
are connected with one small cross beam 21, respectively. The
middle part of the small cross beam 21 is vertically fixed to the
ends of the main cross beams 20 while the ends of the small cross
beams 21 are curved downwards to be connected to the stub 23. Thus,
one anode has eight steel stubs 23. As shown in FIG. 4B, the bottom
of the stub 23 are fixed to the anode carbon block 9. With the
above construction, double-anode structure for a large capacity or
a ultra-large capacity aluminum reduction pot is made. During the
manufacture of the anode steel stubs, the main cross beams 20, the
small cross beams 21, the cant beams 22 and the stubs 23 are
assembled together with cast steel per processing. The connected
point between the steel stub 23 and the anode rod 24 is located in
a center position where the two small cross beams 21 are
intercrossed. The connection between the steel stub 23 and the
anode rod 24 is achieved by transfer welding by which the aluminum
and the steel can be welded together.
[0082] The anode rod 24 is made of pure aluminum, and in an
example, it has a single weight of 253 kilograms. The lower end of
the rod is welded to the aluminum layer with an explosive welding
process where the aluminum and the steel are welded together. In an
example, the eight steel stubs each has a diameter of 160 mm and a
height of 270 mm. The cross beam has a height of 160 mm. The stubs
23 are placed in an anode carbon bowl at a depth of 100 mm. Cast
iron is poured into the gap between the anode carbon block and
stubs 23 so that they are bonded together. In a specific example,
the steel stubs 23 have a current density of 0.104 A/mm.sup.2 and
the weight of about 900 kilograms. Four carbon bowls provided on
the surface of each anode carbon block 9 has an inner diameter of
190 mm, a depth of 115 mm, central distance of 360 mm, and a weight
of each carbon block about 900 kilograms. The weight of each anode
assembly is about 3 tons. There are 24 anode assemblies to be
provided on each pot, and the total weight is about 72 tons.
[0083] 24 anode assemblies in two rows are hung on the two anode
busbar beams of the aluminum reduction pot superstructure. It is
clamped by a cabin type fixture with a chucking power about 18 tons
and torsion torque about 35 kilogram/meter.
[0084] 3) Anode Busbars, Anode Clamp, and Anode Lifting Device
[0085] As shown in FIGS. 1 and 2, the anode busbar 5 of each pot is
connected by four cast aluminum busbars of 8350 mm.times.550
mm.times.180 mm. Two anode busbars 5 on each long side of the pot
are connected by flexible busbars. The anode busbars 5 on both long
sides of the pot are connected with aluminum sheet. Corresponding
to the power incoming mode of the riser busbars, there are six
balance busbars made of the welded aluminum sheet. The other end is
connected to the anode rod (made of aluminum) 24 with the anode
clamp 6. The total weight of the anode busbar is about 10.8
tons.
[0086] Each pot is equipped with an anode lifting device 7
comprised of eight screw elevators. The motor has a power of 13.5
KW. The anode lifting device 7 is mounted over a lateral side of
the steel frame of the aluminum reduction pot superstructure, with
a stroke of 400 mm, the lifting velocity of 75 mm/min, and lifting
capacity of 120 tons, in which the stroke is displayed in an anode
stroke counter. The anode busbar lifting device has the total
weight of 2.6 tons.
[0087] The anode arrangement of the pot is shown as FIG. 5.
[0088] There are 24 anode assemblies provided in the aluminum
reduction pot cavity 25. Two rows of anode carbon blocks 9 are
symmetrically distributed along an axis of longitudinal central
line of the aluminum reduction pot. Eight feeding points 26 are
provided in the aluminum reduction pot, a centre gap 29 is provided
between the two rows of anode carbon blocks opposed with each
other, with a width of 50-120 mm. At the feeding point, the gap 27
between two adjacent anode carbon blocks has a width of 40-80 mm.
The gap 28 between two adjacent anode carbon blocks where the
feeding point is not provided, has a width of 20-50 mm. Compared
with the gaps between conventional anode carbon blocks in the
existing aluminum reduction pot, it is reduced greatly. The
difference between the anode carbon blocks of the present invention
and the conventional ones, the carbon block, which has the same
size as that of the conventional carbon blocks, has been cut off
two corners along the longitudinal end, the cut corner may be a
shape of 90.degree. sector, or an isosceles right-triangle.
[0089] 4) Crust Breaking and Feeding Device
[0090] The crust breaking and feeding device 8 comprise of a crust
breaking cylinder, a impact head, a constant volume feeder and a
feeding hopper. For one aluminum reduction pot, there are seven
sets of cylinders in total, and one set of the cylinders is used
for aluminum tapping. Six crust-breaking cylinders are provided
with the impact heads for breaking the crust, and one remaining
cylinder is for aluminum tapping, which has an inner diameter of
160 mm, a stroke of 650 mm, and a striking velocity of 0-80
centimeter/sec. The six crust breaking and feeding cylinders with
the impact heads each has an inner diameter of 125 mm, a stroke of
550 mm, and a striking velocity of 0-80 centimeter/sec. Eight
constant volume feeder each has an inner diameter of 70 mm. Two
constant volume feeders are used for feeding fluoride salt and six
for feeding alumina, with a constant volume of 1.6 kilograms and
the compressed air pressure of about 0.7 MPa.
[0091] Single crust-breaking cylinder for aluminum tapping has a
weight of 118 kilograms. Single feeding unit has a weight of 103
kilograms. Single constant volume feeder has a weight of 55
kilograms. The total weight of the crust-breaking and feeding
device is about 1.176 tons.
[0092] 5) Fume Collecting and Exhausting System
[0093] The fume collecting and exhausting system of the aluminum
reduction pot is shown in FIG. 6A. First of all, anode balance
busbar 34 is shifted up from the original position to the central
position of the anode busbar 5. The lower portion of the feeding
hopper is not welded to the upper chords 15. Instead, it has a
V-shaped configuration. The flue branch pipe 32 is placed in the
left and right interlayers between the horizontal hood plate 33 and
the feeding hopper 30 to form two flue branch pipes 32 in a
parallel mode. As shown in FIG. 6B, one is an air inlet with a
front opening while the other is an air inlet with a rear opening.
The pot fume from two flue branch pipes 32 is gathered into the
main flue 12 via flue manifold 35, and then is exhausted into a
scrubbing system. The main flue 12 is provided with a control valve
36, which is used to easily adjust negative pressure and fume flow
in the two parallel flue branch pipes 32.
[0094] 6) Anode Rod Sealing Device
[0095] As shown in FIG. 7, the anode rod sealing device of the
present invention is comprised by a lateral plate 37, a front end
plate 38, and a top plate 39. The anode rod is surrounded by the
three plates to form a cavity around it.
[0096] Firstly, a grating structure is adopted in the three
surrounded sides of the anode rod at a front end of the cavity.
Secondly, the rear end of the cavity is welded to the side wall of
the flue and is connected to the horizontal hood plate 33. Thirdly,
the cavity is provided over the horizontal hood plate 33 which is
used as a bottom plate.
[0097] The manufacture of the sealing device is as follows:
[0098] First of all, one or more apertures are drilled at a preset
position in the horizontal hood plate of each anode rod. Two
lateral plates 37 are welded to the horizontal hood plate 33 and
then the top plate 39 is welded thereto. An opening where the rod
can be received therein is provided in the front end of the top
plate. The sectional dimension of the opening is the same as that
of the rod. The top plate and the rear ends of the two lateral
plates are welded to side walls of the flue to be communicated with
the horizontal flue. When the aluminum reduction pot works,
negative pressure is generated around each anode rod due to the
suction force from the flue. By this way, the pot fume escaped from
the gaps of the anode rod 24 is sucked into the horizontal
flue.
[0099] 7) Air Supply Pipeline and Silencer for Tailed Air from the
Crust Breaking and Feeding Device
[0100] As shown in FIG. 10, along the direction of the rectangular
steel pipe upper chord 15 and the direction of the rectangular
steel pipe straight web member 17, crust breaking cylinder 62 with
a self-electromagnetic valve, feeding cylinder 63 with a
self-electromagnetic valve, blast pipe 64 for crust breaking
cylinder and crust breaking cylinder return air pipe 65, a feeding
cylinder blast pipe 66 and a return air pipe 67 for the feeding
cylinder, and, a backblowing air pipe 68, are connected in
sequence. The compressed air pipe 69 connected to the compressed
air main pipe is connected to the rectangular steel pipes in the
upper portion of the pipe truss girder via a one-way control valve
70. The air is supplied from the rectangular steel pipes to the
crust breaking cylinder and the feeding cylinder. Each crust
breaking cylinder is connected to the rectangular steel pipes via
the blast pipe for crust breaking cylinder and return air pipe for
the crust breaking cylinder. Each feeding cylinder is connected to
the rectangular steel pipes via blast pipe for the feeding
cylinder, the return air pipe for the feeding cylinder, and the
backblowing pipe. After the crust breaking and the feeding, the
tailed air from the cylinder is led to the rectangular steel pipe
of the straight web member via the cylinder tailed air exhausting
pipe 71 so as to achieve silencing. Both the crust breaking
cylinder and the feeding cylinder have self-electromagnetic valves,
which can perform crust breaking and feeding operations through the
single-point, the multiple-point and partition control by a pot
control box.
[0101] One set of cylinder for aluminum crust breaking operation is
separately provided at the aluminum tapping end. Alternatively, the
crust breaking operation can be separately done by means of a
manual control valve 72.
[0102] 2. The Cathode Structure for the Aluminum Reduction Pot
[0103] The cathode structure for the aluminum reduction pot is
comprised by a pot shell structure, a cathode lining structure, and
a cathode busbar arrangement structure.
[0104] 1) Pot Shell Structure
[0105] The pot shell structure is comprised by two long lateral
plates, two short lateral plates, one bottom plate and 29 cradles,
the pot body has a boat shape in the bottom of the long lateral
plate.
[0106] The aluminum reduction pot comprises 29 cradles, in which
two are welded to the pot shell and the remaining 27 cradles are
provided in the middle bottom of the pot body with a central line
distance of 640 mm, and connected to the pot shell so as to support
the pot body. Aluminum silicate sheet having a thickness of 10 mm
is provided under the bottom of the pot body to reduce the heat
conduction from pot body to the cradles, in order to ensure that
the stress between the pot body and the cradles is even. There is
15 mm gap between the pot side and the cradles to eliminate the
heat conduction between the pot body and the cradles, to decrease
the probability of the reduced heating intensity of the
cradles.
[0107] The upper portion of the pot body has a single-layer
enclosure structure, which is connected by the bolt to the cradles,
and calcium silicate sheet is sandwiched there between for thermal
insulation. The pot body has a inside size of 18740 mm (the
length).times.4160 mm (the width).times.1506 mm (the height), and a
weight of about 21.8 tons.
[0108] The bottom beam of the cradle is configured to be a H-shaped
steel of 496 mm, the lateral beam has a height of 1318 mm. The
bottom beam and the lateral beam are welded together by means of
steel sheets. One cradle has a weight of 0.795 ton, and 27 cradles
have a total weight of 21.5 tons.
[0109] The cradles are set on two H-shaped steels each having a
height of 300 mm, with an insulation layer being supported on a
concrete buttress pier. The pot shell has a weight of about 46.1
tons.
[0110] 2) Cathode Lining Structure
[0111] The cathode lining structure is comprised of cathode carbon
blocks 9, and lining structures. Specifically, the cathode lining
structure comprises:
[0112] 2.1) Cathode Carbon Blocks 10 Assembly
[0113] The cathode carbon block 10 assembly is comprised of steel
collector bars, ramming paste, and cathode carbon blocks.
[0114] The cathode carbon block has two grooves, each having 120 mm
(in width), 200 mm (in depth), and 250 mm (in center distance of
the groove). Four steel collector bars each of 90 mm.times.180
mm.times.2100 mm are placed in there between and are connected by
ramming with cathode carbon paste. The length of the steel bar is
4460 mm.
[0115] The cathode carbon blocks has a weight of 1.456 tons, the
four steel collector bars have a weight of 1.059 tons, the cathode
paste has a weight of 70 tons, the cathode carbon block assembly
has a weight of 2.58 tons, 28 cathode carbon block assemblies in
each pot have a total weight of 72.24 tons.
[0116] The gaps between these cathode carbon blocks are 30 mm,
which are filled by the bottom carbon paste and tamped into a
whole. The area occupied by the gaps is 17610 mm.times.3650
mm.sup.2.
[0117] 2.2) Lining Structure
[0118] As shown in FIG. 8, the bottom surface of the aluminum
reduction pot is provided with the thermal baffle 41, high
temperature resistance thermal baffles 42, heat insulation bricks
43, and the bath corrosion resistance bricks 44 at two ends of the
pot in sequence. The middle portion thereof is paved with granular
refractory material 40. A layer of aluminum sheet or aluminum foil
is provided thereon after the granular refractory material 40 is
compacted. After installation of heat insulation layer of the pot
bottom being finished, the cathode carbon blocks 10 are provided,
and cathode steel collector bars 51 surrounded by the refractory
insulating papers 50 are inserted into the cathode carbon blocks
10. Steel bar paste 52 is filled into the gaps between the cathode
collector bars and the cathode carbon blocks. The cathode steel
bars are exposed on the cathode carbon blocks, the cathode steel
bars which inside the pot shell are clamped down with the U-type
metal plate 46, and then, filled with the refractory castable 47
and the heat insulation felt 45. The side wall of the aluminum
reduction pot is built with silicon carbide bricks 48, while both
ends of the cathode carbon blocks, the refractory concrete, and the
silicon carbide bricks are filled with arc side paste 49.
[0119] The side carbon blocks have a weight of about 5.7 tons, the
carbon paste has a weight of about 11.6 tons, the bottom refractory
insulation layer has a weight of about 31.26 tons, the lower side
structure has a weight of about 8.8 tons, and, the lining has a
weight of about 129.6 tons.
[0120] 3) Cathode Busbar Arrangement Structure
[0121] As shown in FIGS. 9A and 9B, electricity supply of the
aluminum reduction pot is provided by 28 assemblies of cathodes (56
cathode flexible busbars) and 6 riser busbars 61 at the pot side.
The distribution proportion of the cathode flexible busbar
connected to the 6 riser busbars is 10: 9: 9: 9: 9: 10,
respectively. Such allocation both provides convenience for
electric balance design and helps relatively balanced magnetic
distribution in the liquid aluminum while avoiding excessive
vertical magnetic field gradient. There are busbar 53 on power
incoming side, end bypass busbar 54, pot bottom busbar 55, local
compensation busbar 56, busbar 57 on outgoing side, riser busbar
58, cathode flexible busbar 59 on power incoming side, and, cathode
flexible busbar 60 on outgoing side. According to the distribution
of the soft busbars, the soft busbar and the vertical busbar are
connected by these side busbars or bottom busbars. Further, the
short-circuit busbar is provided to form the busbar structure
around the aluminum reduction pot.
[0122] The magnetic fields at four corners of the aluminum
reduction pot are relatively great and usually higher than 40
Gauss. Accordingly, compensation for over current passing the ends
is required. Because two corners in the outgoing side have greater
resultant magnetic field, each corner in the outgoing side require
more compensation current. That is, where a high magnetic field
exists, a high compensation is needed, and, where a low magnetic
field exists, a low compensation is needed.
[0123] It should be indicated that, the present invention is a
combination for many inventions. The present invention integrates
many innovated technologies including the anode arrangement,
sub-section fume collecting and exhausting system, the anode rod
sealing technology, and the cathode busbar arrangement structure.
The 400 kA high energy efficiency reduction pot according to the
present invention has remarkable energy-saving and emission
reduction effect, thus having great economic benefits and technical
progress over the conventional techniques
* * * * *