Information
-
Patent Grant
-
6231430
-
Patent Number
6,231,430
-
Date Filed
Wednesday, September 29, 199925 years ago
-
Date Issued
Tuesday, May 15, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Lanier Ford Shaver & Payne P.C.
- Berdan; David L.
-
CPC
-
US Classifications
Field of Search
US
- 451 28
- 451 51
- 451 54
- 451 57
- 451 59
- 451 67
- 451 69
- 451 177
- 015 89
- 015 90
- 015 91
- 015 931
- 134 6
- 029 8101
- 029 8111
- 029 8116
-
International Classifications
-
Abstract
The present invention is directed to improved apparatus' for dislodging and abrading cryolite encrustations from carbon anodes spent during aluminum smelting. Both the plow blade and flailing elements of the present invention are constructed and arranged to substantially conform to the shape of the spent carbon butts to facilitate rapid and efficient cleaning of the spent carbon anodes' surfaces. Systems and methods employing the substantially V-shaped plow blade extension and dual directional rotating flailing assemblies are also disclosed.
Description
BACKGROUND OF INVENTION
1. Field of Invention
The present invention relates generally to the field of carbon electrode cleaning, and more particularly to the cleaning of spent frame mounted carbon butts following an aluminum smelting process.
2. Technical Background
Aluminum smelting is a chemical reduction process which converts alumina (aluminum oxide) into aluminum and oxygen. The reduction process is typically preformed in a large reduction cell that includes a carbon lined container or “pot” at least partially filled with a molten mixture of alumina dissolved in cryolite and other materials such as fluorides. The carbon lined steel pot forms the cathode while a plurality of frame mounted carbon blocks suspended in the bath form the associated anodes.
During smelting, a voltage potential is applied between the carbon anodes and the pot, resulting in a large current flow from the anodes through the molten bath mixture to the cathode. The electrical current passing through the bath reduces the alumina into its aluminum and oxygen components, which results in the aluminum ions falling from the mixture to the bottom of the pot and oxygen ions reacting with the carbon provided by the carbon blocks to form CO and CO
2
. Thus, while aluminum is being formed, the carbon blocks are slowly being consumed over time due to the ongoing chemical reaction of the oxygen with the carbon. Generally, these waste gasses are vented from the pot and the non-suspended aluminum is periodically evacuated from the cell. Over time, this reaction necessitates the replacement of the spent anodes in order to maintain adequate production levels of aluminum.
A by-product of the above-described reaction is the formation of a hardened crust atop the cell. The crust is predominantly formed of cryolite, which over time, begins to accumulate on the carbon blocks and their associated support stubs. Thus, when the anodes are removed from the bath, the remaining carbon remnants or butts supported on the frame of the anodes are substantially covered by a hardened encrustation of cryolite, which until removed, prevents reuse of the remaining carbon butts. Because recycled carbon seasoned by aluminum smelting is preferable to non-seasoned carbon for new or replacement carbon anodes used in aluminum smelting, aluminum manufacturers favor removal of the cryolite encrustation from the spent carbon anodes over disposal of the encrusted anodes as carbon butts can be recycled and reused to make new carbon blocks for later use in the smelting process.
Heretofore, several methods have been employed to remove the cryolite encrustation from the carbon anodes. One such method involves a combination of manually hammering and scrapping the anode to substantially remove the hardened encrustation. Another method employs powered scraping arms, which act upon the cryolite. Still another method employs a vibrating scraping tool. Each of these methods, however, are labor intensive, time consuming, and are generally viewed by the industry as too slow to keep pace with aluminum smelting plants. As many smelting plants typically manufacture their own electrodes as a companion function to smelting, the electrode manufacturing process must keep in step with the smelting process. Accordingly, anode cleaning processes must adhere to strict time guidelines in order to provide the requisite number of cleaned carbon butts desired for new or replacement carbon anode manufacture.
In addition, due to technological advances in reduction cell operation, aluminum smelting plants can now add heavier blankets of alumina to the production cell, which in turn fosters the formation of a thicker and denser crust atop the reduction cell and thus provides for greater heat retention. While this is preferable for increased aluminum output, these advances have resulted in the formation of harder and denser cryolite encrustation formed on the spent anodes.
Accordingly, there is a need for an approved carbon electrode cleaning system and method capable of disengaging these harder cryolite encrustations from the anode frames and carbon butts. More specifically, there is a need for a cleaning system that substantially conforms to the shape of typical carbon butts that remain affixed to the stubs of the anodes so that the encrustation can be removed without additional labor intensive and time consuming manual cleaning operations. Such a device should be simple to use, consistent in operation, and capable of keeping pace with modem smelting and carbon anode reclamation processes preformed at aluminum processing plants. It is to the provision of such a system and method that the present invention is primarily directed.
SUMMARY OF INVENTION
One aspect of the present invention relates to a method of cleaning a spent carbon anode, the spent carbon anode including a carbon butt, a frame having a yolk and stub for supporting the carbon butt, and an encrustation affixed to the spent carbon anode. The method includes the steps of urging a plow blade into and through the encrustation such that the plow blade passes between the frame and carbon butt to disengage a significant portion of the encrustation from the spent carbon anode. The method further includes the step of rotationally engaging the frame and carbon butt with first flailing elements rotating in a first plane with respect to the spent carbon anode to abrade additional encrustation from the spent carbon anode. The frame and carbon butt are also rotationally engaged by second flailing elements rotating in a second plane with respect to the spent carbon anode to further abrade additional encrustation from the spent carbon anode. Rotation of the flailing elements in the second plane is substantially orthogonal to rotation of the flailing elements in the first plane.
In another aspect, the present invention is directed to a system for cleaning a spent carbon anode. The spent carbon anode includes a carbon butt, a frame including a yolk and stub for supporting the carbon butt, and an encrustation affixed to the spent carbon anode. The system includes a conveyer for transporting the spent carbon anode, and a first station communicating with the conveyer to receive and engage the spent carbon anode. The first station includes a plow assembly having a laterally extendable plow blade constructed and arranged to dislodge a significant portion of the encrustation from the spent carbon anode as the plow blade is extended through the spent carbon anode between the carbon butt and the frame. A second station communicating with the conveyer downstream of the first station receives the spent carbon anode conveyed from the first station. The second station includes a first rotatable flailing assembly having first flailing elements constructed and arranged to rotatably engage the spent carbon anode in a first plane to abrade additional encrustation from the spent carbon anode. A third station communicates with the conveyer downstream of the second station to receive the spent carbon anode conveyed from the second station. The third station includes a second rotatable flailing assembly having second flailing elements constructed and arranged to rotatably engage the spent carbon anode in a second plane to abrade additional encrustation from the spent carbon anode. Again, rotation in the second plane is substantially orthogonal to rotation in the first plane.
An additional aspect of the present invention relates to an apparatus for removing an encrustation from a spent carbon anode having a carbon butt defining at least one concave groove on its upper surface, and a frame having a yolk and stub for supporting the carbon butt. The apparatus comprises a drive motor, a shaft rotatably coupled to the drive motor, and an elongated flailing element affixed to the shaft at a location remote from the drive motor. The elongated flailing element is constructed and arranged to substantially conform to the shape of the concave groove defined in the upper surface of the carbon butt upon rotation of the shaft.
Yet another aspect of the present invention is directed to an apparatus for removing an encrustation from a spent carbon anode including a carbon butt defining at least one concave groove on its upper surface and a frame having a yolk and stub for supporting the carbon butt. The apparatus includes a drive motor, a plow beam extendably coupled to the drive motor, and a plow blade affixed to an end of the plow beam remote from the drive motor. The plow blade includes a blade extension that is sized and shaped to substantially conform to the shape of the concave groove, and is adapted to dislodge a substantial portion of the encrustation from the concave groove upon extension of the plow beam.
The improved carbon electrode cleaning system and method of the present invention results in a number of advantages over other devices and methods known in the art. For example, the improved plow blade of the present invention is sized and shaped to engage the encrustation at the crust line adjacent the upper surface of the carbon butt within the concave groove defined thereon. Rapid disengagement of the encrustation from the carbon butt is thus facilitated enabling the plow blade to pass through the entire length of the spent carbon anode in a single stroke. Other devices lacking this feature, have been known to stall at some point during the initial stroke.
Additionally, the use of the dual directional flailing assemblies in accordance with the present invention provides substantially more scrubbing of the spent carbon anode surface area in a much shorter period of time than other systems and methods presently known in the art. As a result, the yolk, stubs, and carbon butt of the spent carbon anodes carry far less residual encrustation following cleaning in accordance with the present invention.
Moreover, the unique curvilinear orbital path of the flailing elements of one embodiment of the flailing assemblies of the present invention enable the flailing assembly to be laterally inserted between the yolk, stubs and upper surface of the carbon butt. The construction and arrangement of these flailing elements further facilitate cleaning of the concave groove defined within the upper surface of the carbon butt, as the flailing elements substantially conform to the shape of the concave groove. Accordingly, manually manipulated tools are no longer necessary for carbon butt groove cleaning.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the invention as described herein.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide further understanding of the invention, illustrate various embodiments of the invention, and together with the description, serve to explain the principles and operation of the invention.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1
is an end elevational view of a typical frame mounted carbon block used in the manufacture of aluminum;
FIG. 2
is a side elevational view of the frame mounted carbon block of
FIG. 1
;
FIG. 3
is an end elevational view of a spent carbon anode encrusted in cryolite;
FIG. 4
is a side elevational view of the spent carbon anode of
FIG. 3
shown encrusted in cryolite;
FIG. 5
is a side elevational view of a preferred embodiment of the plow assembly illustrating a spent carbon anode cleaning step in accordance with the present invention;
FIG. 6
is a top plan view of the plow assembly of
FIG. 5
depicting a spent carbon anode cleaning step in accordance with the present invention;
FIG. 7
is a front elevational view of a preferred embodiment of the plow blade of the present invention;
FIG. 8
is a front elevational view of the plow blade of
FIG. 7
shown mounted on a plow beam;
FIG. 9
is a cross-sectional view of the plow assembly of
FIG. 5
taken generally along line
9
—
9
in
FIG. 5
;
FIG. 10
is a top plan view of a plurality of plow assemblies shown configured for cross-plow operation;
FIG. 11
is a top plan view of a plurality of plow assemblies shown configured for both in-line plow and cross-plow operation;
FIG. 12
is an end view of a spent carbon anode shown approaching a preferred vertically mounted horizontal flailing assembly station in accordance with the present invention;
FIG. 13
is a side elevational view of a spent carbon anode shown passing through the vertically mounted horizontal flailing assembly station of
FIG. 12
in accordance with the present invention;
FIG. 14
is a side elevational view of a preferred horizontally mounted vertical flailing assembly in accordance with the present invention;
FIG. 15
is a side elevational view depicting the operation of the horizontally mounted vertical flailing assembly of
FIG. 14
;
FIGS. 16 and 17
depict the operation of a preferred horizontally mounted vertical flailing assembly station in accordance with the present invention;
FIG. 18
is a top plan view of an alternate vertical flailing assembly station in accordance with the present invention; and,
FIG. 19
is an end elevational view of a spent carbon anode shown positioned within a preferred bottom cleaning station in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2
generally depict typical frame mounted carbon blocks
10
, which form the anodes within aluminum reduction cells employed in aluminum smelting facilities. Frame mounted carbon block
10
generally includes a steel yolk
12
having a plurality of stubs
14
depending therefrom. Generally speaking, an iron mounting block
18
is affixed to each steel stub
14
, and is threaded or otherwise textured to support a carbon block
18
thereon. Although not shown in the drawing figures, an electrically conductive bar or riser (not shown) typically extends vertically from yolk
12
to support frame mounted carbon block
10
within the bath (not shown). The riser (not shown) is generally constructed of a lower resistive material than steel, such as aluminum, to reduce electrical losses over its length. Once suspended within the bath mixture (not shown) aluminum reduction ensues with a majority of the bath mixture (not shown) being maintained in a molten state. Over time, however, an upper layer of the bath material is cooled by exposure to the atmosphere surrounding the non-emersed portion of frame mounted carbon block
10
to form a crusted upper layer. This solid bath layer acts as an insulator to efficiently retain heat within the pot (not shown). When carbon blocks
18
are sufficiently spent, the crusted upper layer is physically broken and frame mounted carbon blocks
10
are extracted from the molten mixture (not shown) for replacement.
When removed, spent carbon anodes
20
such as those depicted in
FIGS. 3 and 4
are substantially covered with a hardened encrustation
24
formed predominantly of cryolite. During the smelting process, the once substantial carbon blocks
18
are reduced to carbon remanents or butts
22
which are substantially encased within encrustation
24
. Encrustation
24
typically extends upward around at least a portion of stub
14
, and prevents access to the desired carbon butts
22
.
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawing figures to refer to the same or like parts. Although the individual apparatus' and method steps of the present invention are themselves independently inventive, the preferred embodiment of the invention will be described herein with reference to one or more preferred systems for cleaning or stripping encrustation
24
from spent carbon anodes
22
. Additional details relating to one or more conveying mechanisms, cleaning station housings, and associated devices capable of being employed with the inventive system of the present invention can be found in U.S. Pat. No. 4,557,009, entitled, Carbon Electrode Cleaning System, issued on Dec. 10, 1985 to Raymond J. Dill, which is hereby incorporated by reference herein, in its entirety.
An exemplary embodiment of the plow assembly of the present invention is shown in
FIGS. 5 and 6
and is designated generally throughout by reference numeral
26
. Generally speaking, following removal from the bath (not shown) a spent carbon anode
20
preferably is transported to plow assembly
26
via a conventional conveying system (not shown). Spent carbon anode
20
is preferably passed through an entrance door along guide bars (not shown) onto plow assembly
26
where it is engaged by stopping locks
28
and backstop
30
. When engaged, the entrance doors, controlled by a control device such as a computer, automatically close so that spent carbon anode
20
can be acted upon within the first station of the system of the present invention.
Plow assembly
26
preferably includes an axially extending plow which includes an extendable plow beam
34
and an end mounted plow blade
36
. When spent carbon anode
20
is properly positioned on plow assembly
26
, thrust cylinders
38
driven hydraulically by motors and pumps (not shown) are engaged to extend plow beam
34
in the direction of spent carbon anode
20
. As plow blade
36
engages encrustation
24
surrounding spent carbon anode
20
, plow blade
36
is urged through encrustation
24
to its fully extended position
36
′. As a result, large masses of encrustation
24
are dislodged from spent carbon anode
20
and simply fall onto a conveying system or catch basin (not shown) positioned beneath plow assembly
26
.
In order to effectively and efficiently dislodge the massive portions of encrustation
24
from spent carbon anode
20
, plow blade
36
is preferably sized and shaped to substantially conform to the upper surface
40
of the carbon butt
22
, as shown in
FIGS. 7 and 8
. As suggested above with reference to the operation of plow assembly
26
, plow blade
36
is preferably shaped so as to freely pass through a lengthwise void
42
(
FIG. 1
) or a cross void
44
(
FIG. 2
) defined between the upper surface of carbon blocks
18
and yolk
12
. Preferably, plow blade
36
includes a downwardly depending generally V-shaped channel extension
46
that is sized and shaped to substantially mate with the lengthwise groove
48
extending longitudinally along upper surface
40
of carbon butt
22
(
FIG. 3
) and/or the lateral groove
50
extending laterally across upper surface
40
of carbon butt
22
(FIG.
4
). Referring again to
FIG. 7
, plow blade
36
and channel extension
46
are preferably constructed of hardened steel or some other sufficiently hard metal so as to withstand repeated use. In addition, plow blade
36
preferably includes a plurality of apertures
52
for receiving lag bolts or other fasteners so that plow blade
36
can be securely mounted to extendable plow beam
34
as shown in FIG.
8
.
Referring now to the cross-sectional view of
FIG. 9
, when spent carbon anode
20
is properly seated within plow assembly
26
, plow blade
36
passes through lengthwise void
42
such that the bottom edge
54
of plow blade
36
engages the crust line
56
of encrustation
24
formed on carbon butt
22
. As plow blade
36
is urged longitudinally, through spent carbon anode
20
sufficient force is applied at crust line
56
to separate and dislodge the massive portions of encrustation
24
from spent carbon anode
20
. In addition, channel extension
46
ensures that a significant portion of encrustation
24
seated within lengthwise groove
48
is dislodged as well. During operation, backstop
50
(
FIG. 5
) preferably provides the necessary counteracting force to yolk
12
and stubs
14
to facilitate complete passage of plow blade
36
through spent carbon anode
20
. Once extendable plow beam
34
has been fully extended, it is thereafter retracted within plow assembly
26
and spent carbon anode
20
is prepared for the second station of the system of the present invention. If desired, and if time permits, additional plow assemblies
26
can be incorporated into the plowing station of the system of the present invention. One such embodiment could include a pair of staggered plow assemblies
26
arranged on opposite sides of spent carbon anode
20
to permit simultaneous cross void
44
cleaning of spent carbon anode
20
as shown in FIG.
10
. Moreover, as shown in
FIG. 11
, an alternative embodiment could incorporate three plow assemblies
26
to combine both lengthwise void
42
cleaning and cross void
44
cleaning as shown in FIG.
11
.
Following plowing, spent carbon anode
20
carrying residual cryolite encrustation
58
is preferably conventionally conveyed to a second cleaning station
60
, which preferably includes one or more vertically mounted horizontal cleaning assemblies (hereinafter “horizontal flailing assemblies”)
62
as depicted in FIG.
12
. Horizontal flailing assemblies
62
preferably include a plurality of flailing elements, such as steel chains, which are rotatably coupled to elongated generally vertical shafts
66
. Each shaft is preferably separately driven by a dual directional hydraulic motor
67
which in turn causes flailing elements
64
to rapidly rotate about shafts
66
upon activation. It will be understood that other motors such as variable speed motors can be employed as well.
In operation, spent carbon anode
20
is passed longitudinally between a pair of horizontal flailing assemblies
62
as flailing elements
64
are rapidly rotated to occupy a plurality of horizonal abrading planes. Horizontal flailing assemblies
62
are preferably spaced such that spent carbon anode
20
freely passes between shafts
66
while flailing elements
64
make overlapping contact between stubs
14
and a portion of yolk
12
. In addition, additional flailing elements
64
contact the sides and portions of the top surface
40
of carbon butt
22
to affect “scrubbing,” and thus cleaning of the contacted carbon butt surface and frame. In this way, the residual encrustation
58
contacted by flailing elements
64
is rapidly and controllably abraded away from spent carbon anode
20
. Optionally, a third centrally mounted horizontal flailing assembly
62
can be reciprocally mounted above spent carbon anode
20
within second station
60
. If employed, centrally mounted horizontal flailing assembly
62
can be selectively lowered into engagement with the forward and rearward ends of spent carbon anode
20
as spent carbon anode
20
is passed through second station
60
. When employed, it will be understood by those skilled in the art that retraction of the centrally mounted horizontal flailing assembly
62
will be controlled via computer or other control mechanism so that shaft
62
clears yolk
12
of spent carbon anode
20
as spent carbon anode
20
passes through second station
60
. In this way, additional cleaning of the forward and rearward surfaces of spent carbon anode
20
can be affected. Moreover, and as depicted in
FIG. 13
, it will also be understood by those skilled in the art that horizontal flailing assembly
62
can be offset longitudinally with respect to spent carbon anode
20
. Although overlapping of the flailing element
64
will not be affected in such an embodiment, sufficient contact is made between flailing element
64
and spent carbon anode
20
to abrade away much of the residual encrustation
58
carried by spent carbon anode
20
.
Due, at least in part, to the increased hardness of encrustation
24
resulting from improved smelting techniques, and to the shape of upper surface
40
of carbon butt
22
, a significant amount of residual encrustation
58
remains affixed to spent carbon anode
20
following horizontal flailing within second station
60
. As a result, a need has arisen for a device that is capable of scrubbing the unabraded portions of spent carbon anode
20
. A first preferred embodiment of such a device is depicted in FIG.
14
and referred to generally throughout as curvilinear orbital flailing assembly
68
. Curvilinear orbital flailing assembly
68
preferably includes a flail head
70
rotatably coupled to an extendable thrust cylinder
72
both of which are driven by one or more hydraulic motors
74
. Curvilinear orbital flailing assembly
68
further includes a support platform for mounting curvilinear orbital flailing assembly
68
to the support member (not shown) of a third cleaning station housing (not shown).
Flail head
70
preferably includes a plurality of spaced end mounted flailing elements
78
that are loosely affixed to flail head
70
. Thus, upon rotation of flail head
70
, end mounted flailing elements
78
assume a generally curvilinear orbital path about flail head
70
. As shown in
FIG. 15
, and when rotated, end mounted flailing elements
78
essentially conform to the concave shape of the lateral grooves
50
extending along upper surface
40
of carbon butt
22
. As a result, the unabraded residual encrustation
58
residing within lateral grooves
50
on upper surface
40
of carbon butt
22
are scrubbed and abraded away by the rapid rotation of end mounted flailing elements
78
. In addition, contact is also made between end mounted flailing elements
78
and the bottom surfaces of yolk
12
of spent carbon anode
20
. Accordingly, any unabraded residual encrustation
58
residing thereon is also removed.
A preferred embodiment of a third cleaning station
80
incorporating a plurality of orbital flailing assemblies
68
is shown in operation in
FIGS. 16 and 17
. Following horizontal flailing, spent carbon anode
20
is preferably conventionally conveyed end first into third cleaning station
80
until spent carbon anode
20
is engaged by stopping locks (not shown). Once engaged, spent carbon anode
20
is preferably aligned with a pair of longitudinally offset horizontally mounted vertical flailing assemblies
68
spaced on opposite sides of spent carbon anode
20
. Although the horizontally mounted vertical flailing assemblies
68
could incorporate flailing elements similar to flailing elements
64
as described above with respect to second station
60
, horizontally mounted vertical flailing assemblies are preferably curvilinear orbital flailing assemblies
68
substantially similar to those described above with reference to
FIGS. 14 and 15
. More specifically, curvilinear orbital flailing assemblies
68
are preferably positioned with respect to spent carbon anode
20
such that the opposed outer pair of flail heads
70
are aligned to engage the ends of spent carbon anode
20
upon extension of thrust cylinder
72
, while the inner opposed pair of flail heads
70
are positioned with respect to spent carbon anode
20
such that, upon extension of thrust cylinder
72
, flail heads
70
extend into cross voids
44
located between upper surface
40
of spent carbon anode
20
and yolk
12
.
As shown in
FIG. 17
, once a controller (not shown) receives a signal that the stopping locks (not shown) are engaged, motors
74
engage to rotate flail head
70
. Support platforms
76
, preferably powered carrier platforms movable in both the lengthwise and crosswise direction (longitudinally and laterally, respectively), are also engaged to extend thrust cylinders
72
to move rotating flail heads
70
into engagement with spent carbon anode
20
. Once fully extended, the curvilinear orbitally rotating flail heads
70
are positioned at the longitudinal center line of spent carbon anode
20
where residual encrustation
58
remaining on the ends of carbon butt
22
and within lateral grooves
50
will be abraded away. After a predetermined period of time, carrier platforms
76
will be moved laterally with respect to spent carbon anode
20
, first to one side, and then the other, as indicated by directional arrows
82
(FIG.
17
). In this way, surviving residual encrustation
58
affixed to the stubs
14
and yolk
12
is abraded away. When this stage of the cleaning operation is complete, carrier platforms
76
will preferably move orbital flailing assembly
68
to the center or starting position, motors
74
will disengage, and carrier platform
76
will retract thrust cylinders
72
so that spent carbon anode
20
can be moved for further processing.
While the third cleaning station
80
has been described above with reference to a preferred arrangement of curvilinear orbital flailing assemblies
68
, it will be understood by those skilled in the art that other flailing assembly arrangements are encompassed within the scope of the present invention. For example, horizontally mounted vertical flailing assemblies such as curvilinear orbital flailing assembly
68
can be extended into engagement with spent carbon anode
20
from one or both ends of spent carbon anode
20
. Moreover, horizontally mounted vertical flailing assemblies such as curvilinear orbital flailing assemblies
68
can be arranged as a single co-planer bank of flailing assemblies as depicted in FIG.
18
.
A second alternative embodiment of a device for scrubbing the unabraded portions of spent carbon anode
20
following cleaning operations at second station
60
is illustrated in FIG.
19
. In a preferred embodiment of the system of the present invention, the device depicted in
FIG. 19
forms a forth cleaning station
84
for spent carbon anodes
20
. However, it will be understood by those skilled in the art that in some instances sufficient cleaning of spent carbon anode
20
can be affected with less than all of the three flailing stations described herein.
As depicted in
FIG. 19
, fourth cleaning station
84
preferably includes a plurality of opposed horizontally mounted vertical flailing assemblies
86
arranged to engage the bottom
88
of spent carbon anode
20
. Following departure from a previous cleaning station, spent carbon anode
20
is conventionally conveyed into fourth cleaning station
84
until engaged by stopping locks (not shown). Once engaged, motors
74
rotate vertical flailing elements
90
and carrier platforms
92
extends thrust cylinders
94
in the direction of spent carbon anode
20
as indicated by directional arrows
96
. Preferably, horizontal flailing assemblies
86
are offset longitudinally with respect to spent carbon anode
20
so that flailing elements
90
affect overlapping coverage of bottom
88
of spent carbon anode
20
as carrier platform
92
traverses flailing assemblies
86
longitudinally along the length of spent carbon anode
20
. In this way, residual encrustation
58
affixed to bottom
88
of spent carbon anode
20
is abraded away by the rapid rotation of flailing elements
90
. Moreover, flailing elements
90
preferably vary in length with the longest elements residing nearest motors
74
. So arranged, flailing elements
90
substantially conform to the rounded shape of the sides of carbon butt
22
thereby maximizing abrasion coverage for the greatest amount of carbon butt
22
surface area at any given time. In addition, the longer flailing elements
90
reach previously unremoved encrustation
58
extending up the side walls of carbon butt
22
. Upon completion of cleaning within fourth cleaning station
84
, spent carbon anode
20
, preferably void of any residual encrustation
58
, is conventionally conveyed for further processing and/or recycling.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. For example, the above-described flailing stations can be encountered by spent carbon anodes
20
in a different order than that order described above. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
Claims
- 1. A method of cleaning a spent carbon anode, said spent carbon anode comprising a carbon butt, a frame including a yoke and stubs for supporting said carbon butt, and an encrustation affixed to said spent carbon anode, said method comprising the steps of:a) urging a plow blade into and through the encrustation such that said plow blade passes between the frame and the carbon butt to disengage a significant portion of the encrustation from the spent carbon anode; b) rotationally engaging the frame and carbon butt with first flailing elements rotating in a first plane with respect to the spent carbon anode to abrade additional encrustation from the spent carbon anode; and c) rotationally engaging the frame and carbon butt with second flailing elements rotating in a second plane with respect to the spent carbon anode to further abrade additional encrustation from the spent carbon anode, said second plane being substantially orthogonal to said first plane.
- 2. The method of claim 1 further comprising the step of rotationally engaging the bottom of the carbon butt with third flailing elements rotating in a third plane spaced from and substantially parallel to said second plane to abrade additional encrustation affixed to the bottom of the spent carbon anode.
- 3. The method of claim 1 wherein each of said second flailing elements includes a first and second end, and wherein the first and second ends are each attached to said second flailing assembly such that said flailing elements travel in a curvilinear orbital path upon rotation of said flailing assembly.
US Referenced Citations (10)