WO2009003217A1

WO2009003217A1 - Butt press

Info

Publication number: WO2009003217A1
Application number: PCT/AU2008/000930
Authority: WO
Inventors: Gregory Charles Keen
Original assignee: Mkg Technologies Pty Ltd
Priority date: 2007-06-29
Filing date: 2008-06-26
Publication date: 2009-01-08

Abstract

A butt press is provided having gripping members operative to grip a rod of a rodded anode, pressing members operative to press the anode or butt from the rod and a plurality of breaking bars arranged as at least two opposed sets of breaking bars. The breaking bars co-operate to impinge the anode, the anode butt or a piece of the anode or anode butt between the opposed sets of breaking bars to thereby split the anode, anode butt or anode butt piece.

Description

Butt press

Cross-Reference to Related Applications

The present application claims priority from Australian Provisional Patent Application No 2007903514 filed on 29 June 2007, the content of which is incorporated herein by reference.

Introduction

The present invention relates generally to butt presses for the removal of a spent anode from the anode rod and in particular the invention provides an apparatus that breaks the anode into smaller pieces immediately after removal.

Background

Under conventional Rodding room process conditions a butt press removes a spent anode from an anode rod and sends it to the primary crusher via belt conveyor for initial sizing. The primary crusher in a conventional plant must be able to take butts up to a full size anode, which requires a large crusher capable of withstanding a high peak load.

Some prior art butt presses have been mounted directly above the primary crusher to simplify the transport of the butt to the crusher however such arrangements had various deficiencies: L a butt press is a cycle time based machine that will press off the butt in a given time, usually a 1 minute cycle.

2. a crusher is sized based (e.g. tones per hr). A crusher will take a variable amount of time to process each single butt depending on its size, orientation as presented to the crusher, and any remaining product from the last butt presented. 3. the crusher is normally sized for:

Average butt size (tones) X Butts per hr = Crusher capacity (tons/hr)

If a number of large butts are presented to the crusher one after the other it can become blocked due to this surge.

4. normal application of a crusher would include a belt conveyor between the butt press and the crusher and a large crusher feed chute, each designed to cope with surges. 5. if the crusher is placed under the butt press, the separation distance is very great to cope with this instantaneous surge, resulting in an unusually high building in this area and a butt press elevation that makes maintenance difficult.

6. The butt press and primary crusher have always been separate machines, individually mounted and controlled.

Summary

According to one aspect, a butt press apparatus is provided, comprising: i. gripping members operative to grip a rod of a rodded anode; ii. pressing members operative to press the anode or butt from the rod; iii. a plurality of breaking bars arranged as at least two opposed sets of breaking bars operative to impinge the anode, the anode butt or a piece of the anode or anode butt between the opposed sets of breaking bars to thereby split the anode, anode butt or anode butt piece. According to another aspect, a method of removing an anode or anode butt from a rod is provided, comprising: i. gripping a rod of a rodded anode; ii. pressing the butt from the rod; iii. impinging the anode butt or a piece of the anode or anode butt between a plurality of breaking bars arranged as at least two opposed sets of breaking bars; iv. Pressing the opposed sets of breaking bars together to split the anode, anode butt or piece of anode or anode butt.

Preferably each set of breaking bars comprises a matrix of three breaking bars horizontally by three breaking bars vertically (i.e. 9 bars), although other configurations may be effective in different circumstances. The tip of each bar is also preferably tapered and then radiused to form a rounded tip of smaller radius than the rest of breaking bar. Typically the bars of each set are opposed to the corresponding bar of the other set although offset arrangements are also possible.

Preferably retractable support members are provided forming a floor having an opening through which broken off anode or anode butt pieces may fall. When retracted an enlarged opening forms through which any remaining anode or anode butt pieces will fall. Typically the retractable support members will be retracted at the end of each cycle to allow any broken anode or anode butt pieces to fall through. The diameter of the breaking bars may also be selected to allow the breaking bars to be spaced on centres which are less than or equal to the gap between the butt support plates. A first material conveyor is preferably located under the retractable support members such that anode or anode butt pieces fall onto the first conveyor. Preferably also the first conveyor is reversible, such as a reversible vibratory feeder, and carries the anode and anode butt pieces off to another conveyor and on to a crusher. Alternatively the first conveyor when reversed may carry the anode and anode butt pieces off in an opposite direction to a bunker for temporary storage.

The preferred butt press machine removes butts at the press, and within the same machine cycle, auto sizes the butt (or anode) down to 500 x 500 x 500 maximum piece size. Sizing down is done with the breaking bars that are pressed in from the sides of the butt to split it before it leaves the butt press. This is a cycle time based process and is therefore compatible with the butt pressing operation. The smaller pieces can be carried away by conveyor and bunkered if necessary to accommodate breakdowns in the downstream crushing circuit.

Brief Description of the Drawings

Embodiments of a butt press will now be described with reference to the accompanying drawings in which:

Fig. 1 is a plan view of a butt press according to an embodiment of the invention:

Fig. 2 is an elevation view of the butt press of Fig. 1; Fig. 3 is an end elevation of the butt press of figure 1;

Fig .4 is a detailed view of the butt pressing mechanism of the butt press shown in Figs. 1, 2 and 3, showing a Rod with Butt attached as it moves into press with the mechanism open;

Fig. 5 is a detailed view of the butt pressing mechanism similar to that of Fig. 4 but viewed after the Stub collars have moved in to clamp the rod and press plates are in position; Fig. 6 is a detailed view of the butt pressing mechanism in which the Press cylinders are seen pulling up to press the butt off the rod;

Fig. 7 is a detailed view of the butt pressing mechanism showing the butt pressed off and sitting on butt support plates and with the side splitting/breaking blades which move in from both sides to split the butt; Fig. 8 is a detailed view of the butt pressing mechanism showing the side breakers and the butt support table retracted. Detailed description of an embodiment of a butt press

A new Rodding Room facility has been designed for anodes using pre-bake technology. A unique aspect of this facility is the new pre-sizing automated Butt Press for pressing off butts of carbon anodes for recycling. Under conventional Rodding room process conditions the butt press removes the Butt and sends it to the primary crusher via belt conveyor for initial sizing. The primary crusher in a conventional plant must be able to take butts up to a full size anode, which requires a large crusher which must be able to withstand a high peak load. Referring to Figs. 1 to 8, a butt press is illustrated in which the butt is removed by the press and at the same time a splitter auto sizes the pressed off butt down to 500 x 500 x 500 maximum piece size. By reducing the size of butt that the primary crusher must be able to accept this arrangement provides obvious savings to a smelter operator. Conventional arrangements required a crusher to be able to accept up to a full size anode, in the case where a rejected anode had to be recycled, resulting in excessive peak loads requiring a much larger crusher than would be required to handle an average load.

Previously, operators have attempted to solve the problem by the installation of a crusher under the butt press. This solution has some inherent problems. A butt press is a cycle time based machine that will press off the butt in a given time, usually a 1 minute cycle. The size of a crusher on the other hand is determined by required throughput measured in tones per hour. Therefore a crusher will take a variable amount of time to process each butt depending on its size, and the orientation in which it is presented to the crusher. The time to crush a butt will also be extended if there is any product remaining in the crusher from the previous butt to be crushed. The crusher is normally sized to handle a load determined by average butt size, i.e.:

Average butt size (tones) X Butts per hr = Crusher capacity (tons/hr)

If a number of large butts are presented to the crusher one after the other it can become blocked. Normal application of a crusher would include a belt conveyor between the butt press and the crusher and a large crusher feed chute, each designed to cope with any surge. When a crusher is placed under the butt press, the separation distance must be sufficient to cope with the largest potential material surge, resulting in an unusually high building in this area and a butt press elevation that makes maintenance difficult. The crusher and butt press have always been individual machines supported independently.

The proposed Butt press incorporates a butt resizing mechanism that splits the block rather than crushing it. Thus the resizing process can be performed at a fixed cycle time that is commensurate with the butt stripping cycle time.

The butt is caught as it is stripped so that the next butt can be prepared for stripping in parallel with the splitting action to maximize available butt stripping and butt splitting time within the total machine cycle time.

By splitting rather than crushing there is no need for a feed chute and elevated butt press position as there are no surge capacity requirements.

The butt press design also incorporates a two way feeder that allows split butts to be sent either to a butt crusher, or if the downstream crusher system has a breakdown they can be sent to a bunker. This allows the butt stripping process to continue even when the crushing system has a breakdown. The processes are no longer linked. The butt splitting action sends controlled maximum size pieces to the secondary crusher in a fixed cycle time.

With this butt splitting arrangement in place, the plant no longer requires a large opening primary crusher.

Other designers have attempted to solve this problem by crushing the butt from below as part of the butt stripping action. These machines are normally called a BTP or Butt and Thimble press. Because they crush from below they need to restrain the top of the anode and crush against this restraint. It is convenient to also strip the thimbles in these machines and thus avoid a separate thimble press. So past attempts to reduce the size of Butt pieces coming out of the butt press have focused on the following: 1. The butt press has a crusher incorporated below the butt press to crush from below and strip thimbles at the same time. This requires huge forces (500 tons plus) and to pay for this investment they also strip the thimble thus removing the need for a separate thimble press.

2. The crushing function of this design gives highly variable butt piece sizes. In fact a full butt can break off before the press has had time to do any crushing and thus the primary crusher still needs to cope with a full butt size. There are no savings on the crusher equipment with this design.

3. Incorporating a crusher under the butt press is normally only applied to smelters where the anodes have in-line stubs (1, 2, 3 or 4). Even then the outside stubs can toe-in and make it difficult to strip the thimbles. A normal separate thimble press strips 1 stub at a time because of the toe-in issue. 4. In the early 1990's a butt and thimble press was developed for anodes with a spider stub arrangement. The spider stub layout has 2 rows of stubs and either 2 stubs or 3 stubs in each row. This arrangement has not been widely adopted because the distance between stubs changes over many cycles and the stubs suffer a lot of damage and are subject to high repair costs in these types of machines.

The design illustrated in the accompanying drawings achieves a reliable splitting of the block without damage to the stubs and the thimbles are removed by a separate thimble press. This butt press removes and resizes the butt reliably and within cycle time resulting in savings possible due to reduced size and number of crushers required in the process.

It has become a requirement of recent tender specifications, that the maximum size of butt pieces on exit of the butt press be limited. To date all equipment suppliers have achieved this by elevating the butt press and including a crusher underneath with inherent disadvantages as discussed above. Referring again to the accompanying drawings, the top section of the butt press works fairly conventionally, as seen in Figs 4 to 8:

A plan view of a butt press is seen in Fig. 1 which shows the general arrangement of the machinery. Rodded Anode Butts 303 are delivered to the butt press

104 via an overhear conveyor rail 103 where they are suspended from travelling cars 102. Once pressed off the rods 301 and split, the butt pieces fall into a reversible vibratory feeder 801 and under normal circumstances are delivered to a conveyor belt

105 for transport to a crusher. If the re is a problem with the crusher or the conveyor 105 (such as a blockage or equipment failure), butt pieces can be stored temporarily in a bunker 106 by reversing the direction of flow of the reversible vibratory feeder 801. A front view of the butt press can be seen in Fig. 2 in which rodded anodes 310,

303 are seen suspended from the conveyor rail 103 and car 102 by chains 201. In the side view of Fig. 3 we see a rod 301 exiting the butt press after a butt has been pressed off of the rod such that the bridge 313 and stubs 314 are visible.

In Fig .4 we see the is a detailed view of the butt pressing mechanism, showing a Rod 301 with a spent Butt 302 (dashed) and a full butt 303 (light) illustrated superimposed for comparison. As the attached butt 302/303 moves into the press, the mechanism is open with the butt stripping slides 304, the butt stripping plates 306, the rod supporting plates 305 and the butt breaking slide 312 retracted, and the butt support 307 moved forward on the butt support slide 308. The butt stripping cylinders 309 and the rod support cylinders 311 are shown in a neutral state. At this point in the stripping process entry doors (not shown) and exit doors 101 (see fig 1) are open. Referring to Fig. 5 the butt pressing mechanism is shown after the rod supporting plates 305 (Stub collars) have been moved in to clamp the rod 301 and the butt stripping plates 306 are in position.

In Fig. 6 the rod support cylinders 31 lare pulling up on the rod supporting plates 305 to unload the carrier chains, while the butt stripping cylinders 309 are pressing down on the stripping plates 306 to press the butt 302/303 off the rod 301.

Fig. 7 shows the butt pressing mechanism after the butt has been pressed off and is sitting on butt support plates 307. Fig. 7 also shows the butt breaking slide 312 in the advanced position with the side splitting/breaking blades 701 extending in through the wall 702 of the butt pressing chamber from both sides to split the butt 302/303. The butt breaking slides 312 are pushed in by hydraulic cylinders 704 and the exerted force is transmitted through the tips of the side splitting/breaking blades 701 to create very high point forces around the periphery of the butt 302/303 causing the butt to split. In the preferred embodiment each set of side splitting/breaking blades 701 comprises a matrix of three breaking blades horizontally by three breaking blades vertically, although other configurations may be effective in different circumstances. The tip of each blade is tapered and then radiused to form a rounded tip of smaller radius than the breaking blade. The blades of each set are opposed to the corresponding blade of the other set. The gap 705 between the butt support plates 307 is sized to allow butt pieces through if they are smaller than a maximum allowable size. The diameter of the breaking blades are also selected to allow the breaking blades to be spaced on centres which are less than or equal to the gap 705 between the butt support plates 307. If after the side splitting/breaking blades 701 have split the butt a first time. They may be retracted and reinserted if there are still large butt pieces in the chamber. As seen in Fig. 8 after the butt has been pressed off and split into suitably small pieces, the butt support plates are withdrawn by the butt support plate hydraulic cylinders 802 causing any remaining butt pieces to fall through the expanded gap 705a onto a reversible vibratory feeder 801. At this time the butt pressing mechanism comprising the side breakers blades 701 are also retracted as are the butt stripping slides 304, the butt stripping plates 306, the rod supporting plates 305. The butt stripping cylinders 309 and the rod support cylinders 311 will again be in a neutral state.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A butt press apparatus, comprising: i. gripping members operative to grip a rod of a rodded anode; ii. pressing members operative to press the anode or butt from the rod; iii. a plurality of breaking bars arranged as at least two opposed sets of breaking bars operative to impinge the anode, the anode butt or a piece of the anode or anode butt between the opposed sets of breaking bars to thereby split the anode, anode butt or anode butt piece.

2. The butt press apparatus of claim 1 wherein each set of breaking bars comprises a matrix of breaking bars extending by three breaking bars horizontally

3. The butt press apparatus of claim 2 wherein the matrix of breaking bars extends by three breaking bars vertically.

4. The butt press apparatus of claim 2 or 3 wherein the tip of each bar is tapered and then radiused to form a rounded tip of smaller radius than the rest of breaking bar.

5. The butt press apparatus as claimed in any one of claims 1 to 4 wherein the bars of each of the opposed sets are opposed to the corresponding bar of the other set.

6. The butt press apparatus as claimed in any one of claims 1 to 4 wherein the bars of each of the opposed sets are offset to the corresponding bar of the other set.

7. The butt press apparatus as claimed in any one of claims 1 to 6 wherein retractable support members are provided forming a floor having an opening through which broken off anode or anode butt pieces may fall.

8. The butt press apparatus of claim 7 wherein the retractable support members when retracted create an enlarged opening through which any remaining anode or anode butt pieces will fall.

9. The butt press apparatus of claim 7 or 8 wherein the diameter of the breaking bars and their spacing are selected whereby the breaking bars to be spaced on centres which are less than or equal to the gap between the butt support plates.

10. The butt press apparatus of claim 7, 8 or 9 wherein a first material conveyor is located under the retractable support members such that anode or anode butt pieces fall onto the first conveyor.

11. The butt press apparatus of claim 10 wherein the first conveyor is a reversible vibratory feeder and when operated in a forward direction it carries the anode and anode butt pieces off to another conveyor which conveys them to a crusher.

12. The butt press apparatus of claim 11 wherein a bunker is provided for temporary storage and when the first conveyor is operated in reverse direction it carries the anode and anode butt pieces off to the bunker.

13. A method of removing an anode or anode butt from a rod is provided, comprising: i. gripping a rod of a rodded anode; ii. pressing the butt from the rod; iii. impinging the anode butt or a piece of the anode or anode butt between a plurality of breaking bars arranged as at least two opposed sets of breaking bars; iv. Pressing the opposed sets of breaking bars together to split the anode, anode butt or piece of anode or anode butt.

14. The method of claim 13 wherein retractable support members are provided below the breaking bars and are retracted at the end of a pressing cycle to form an enlarged opening through which any remaining broken anode or anode butt pieces will fall.

15. The method of claim 13 or 14 wherein a first material conveyor is located under the retractable support members and anode or anode butt pieces falling through the enlarged opening are collected on the first conveyor.

16. The method of claim 13, 14 or 15 wherein the first conveyor is reversible, and when operating in a forward direction carries the anode and anode butt pieces toward a crusher.

17. The method of claim 16 wherein the first conveyor is able to be operated in a reversed direction to carry the anode and anode butt pieces to a bunker for temporary storage.

18. The method as claimed in any one of claims 13 to 17 wherein a butt is removed, and within the same pressing cycle, the butt (or anode) is auto sized down to a 500 x 500 x 500 maximum piece size.

19. The method of claim 18 wherein the sizing down is done with the breaking bars that are pressed in from the sides of the butt to split it.

20. The method of claim 18 or 19 wherein smaller pieces resulting from the splitting operation are carried away by conveyor toward a crusher.

21. The method of claim 18 or 19 wherein smaller pieces resulting from the splitting operation are carried away by conveyor to a bunker, where they are stored awaiting crushing.

Dated this twenty-sixth day of June 2007

MKG Technologies Pty Ltd Patent Attorneys for the Applicant: F B RICE & CO