EP0121954A1

EP0121954A1 - Apparatus for the positioning and filling of protective sleeves on an anode block

Info

Publication number: EP0121954A1
Application number: EP84200262A
Authority: EP
Inventors: Hendrik Mekkering; Cornelis Johan De Boer
Original assignee: Aluminium Delfzijl BV
Current assignee: Aluminium Delfzijl BV
Priority date: 1983-02-25
Filing date: 1984-02-24
Publication date: 1984-10-17
Also published as: EP0121954B1; NO161330C; IS1282B6; NO161330B; NL8300711A; IS2882A7; DE3460591D1; NL182740C; NO840719L; NL182740B

Abstract

Apparatus for the positioning and filling of the two protective sleeves around the attachment of the anode rod to an anode block is designed to achieve accurate positioning and filling of the sleeves. The apparatus has a horizontal conveyor 1 on which the anode block 2 with the anode rod and the two protective sleeves 4 fixed thereon are conveyed to the filling position, and a pair of filling troughs 7, 8 located above the openings of the sleeves at the filling position and each connected to a feed hopper 9, 10 for the granular tar-containing mass being filled. A set of pushing means 13,14 on either side are movable above the top of the anode block 2 to locate and maintain the sleeves and are also arranged to function as collecting troughs for any material spilled during filling. Conveying means 20, 21 are provided for transporting the collected spilled material back to the feed hoppers 9,10.

Description

The invention relates to an apparatus for the positioning and filling of protective sleeves around the attachment of an anode rod to an anode block.
In the electrolysis of alumina to aluminium, use is made of carbon anode blocks which, suspended on an anode rod, are immersed in the fluid salt. The attachment of the anode block to an anode rod is achieved with a steel fork piece. The anode block is provided on its upper side with two rectangular cavities about 8.5 cm deep into which fit the two stubs or extremities of the fork piece. The cavities are filled with an electrically conductive, e.g. tar-containing, tamping mass, and in order to increase adhesion the bottoms of the extremities of the fork piece have a horizontal weld bead. In order during .. operation to protect the steel fork piece above the anode block against attack by the hot salt because of its dissolving power, two protective sleeves of aluminium are fixed around it. Such a sleeve consists for example of a strip of aluminium about 10 cm high with four right- angled bends, which is fixed around the end of the fork piece. The sleeve is then filled with the granular tar-containing mass. This aluminium sleeve is by itself just a temporary protection, since during operation the aluminium melts away very rapidly and the granular tar-containing mass which it surrounded remains as a sintered protection for the fork piece.
It is important that the sleeves should be properly positioned with respect to the anode block. The invention has the object of providing an apparatus for the positioning and filling of the two protective sleeves.
The invention is set put in claim 1.
In this way it is possible to minimize or prevent corrosion of the stumps of the anode rod as a result of inaccurate positioning of the sleeves, while a considerable saving is achieved by collecting and returning spilled granular material.
Since the capacity of the sleeve around the extremity of the anode rod is accurately known in advance, it is also known how much material must be placed in the space. For this purpose the outlets of the hoppers are preferably provided with a measuring device capable of delivering the desired amount.
It is in addition preferred if the filling means take the form of vibratory troughs- For this purpose control means can be provided which activates the vibratory troughs for a certain time in order to shake the desired quantity of material down into the protective sleeves.
An embodiment of the invention will be described below by way of example with reference to the drawings, in which:-

Fig. 1 is a front view of the apparatus embodying the invention,
Fig. 2 is a side view thereof,
Fig. 3 is a top view of the apparatus.

Fresh carbon anode blocks are supplied in the anode shop, having already on their upper surface two rectangular cavities of about 8.5 cm depth. An anode rod is fixed into each anode using a steel fork piece. The two extremities of the legs of the fork piece have a weld bead along the lower edge of one side. The legs of the fork piece (with the anode rod above) are placed in the cavities of the anode block, and alongside the weld bead a tar-containing mass is tamped in using an L-shaped knife, for the purpose of ensuring a good electrically conductive connection between anode rod and anode block. Subsequently the anode, consisting of anode block and anode rod is transported to the apparatus according to the invention by means of an intermittently stepping horizontal conveyor, as shown in the drawing. In Fig. 1 the horizontal conveyor is indicated by the reference number 1. The anode block 2 is situated on it together with the attached fork piece 3 of the anode rod. At an earlier -stage the aluminium protection sleeves 4 have been fixed around the two extremities of the fork piece. It is necessary to position these protective sleeves relative to the fork piece and to fill the space between fork piece and protective sleeve with a granular tar-containing mass. In the top view of Fig. 3 the horizontal section of the fork piece is shown hatched by reference number 3, and the mass tamped into the aforementioned rectangular cavities is indicated by 5 and 6. The two sleeves 4 are also visible. The space between the extremities of the fork piece and the sleeves must be filled with a granular tar-containing mass which is introduced at both sides via two pairs of vibratory troughs 7 and 8. These vibratory troughs are filled from hoppers 9 and 10 respectively, and the outlets of these have a measuring gate 11 which is arranged to deliver a predetermined quantity of the filling material from the hopper. A cylinder 12 on each of the hoppers 9,10 operates this dosing gate.
It is of real importance that the anode block 2 is brought to the exact position in the apparatus by the conveyor 1.
For the purpose of positioning the sleeves 4 (see Fig. 3) on the upper surface of the anode block 2, there are pushing means 13 and 14. The generally W-shaped pushing face of these has straight sections of the same length as the sleeve (see Fig. 3). 'These pushing means 13 and 14 can each pivot on a horizontal shaft 15 and 16- and are moved towards and away from the anode rod 3 by means of cylinders 17 and 18 (see Fig. 1). As may be seen from Fig. 3, the sleeves are well positioned by the oblique sections of the W-shaped faces of the pushing means 13 and 14 when these pushing means are lowered. During filling of the sleeves 4 from the vibratory troughs 7 and 8 these pushing means 13 and 14 remain with their edges resting against the sleeves 4. Any spilled material which may fall over the edge of the sleeves 4 is collected in the pushing tools which are shaped as collecting troughs. The spilled material can then return via a chute 19 and 20 into a horizontal screw conveyor 21 which is driven by an electric-motor 22 via a right angled gear drive 23. The spilled material can be collected in a tray 24 and from there be returned to hoppers 9, 10 by a vertical conveyor which is indicated schematically at 25 in Fig. 3.
The pushing means 13 and 14 which are designed as centering pieces and collecting troughs are connected to the chutes 19 and 20 by dust-proof flexible connecting hoses 26, 27.
After the sleeves 4 have been positioned and filled, the granular tar-containing mass is heated on the upper surface with a burner, so that a crust forms to prevent spillage from the mass during further transport of the anode and at the same time to fix the position of the sleeves 4 on the anode block.

Claims

1. Apparatus for the positioning and filling of protective sleeves around the attachment of an anode road to an anode block,
characterized by

a horizontal conveyor (1) adapted to carry the anode block (2), with the anode road (3) fixed thereon and the protective sleeves (4), to a filling position;

filling means (7,8) which at said filling position are located above the respective openings of the sleeves (4) and which are each connected to a feed means (9,10 ) for the material to be filled into the sleeves;

pushing means having opposed members (13,14) which are movable above the top of the anode block (2) at the filling position so as to locate and maintain the sleeves accurately at the desired location during filling, said members are also shaped and arranged as collectors for any material spilled during filling, and

conveying means (20,21) for transporting the collected spilled material back to the feed means (9,10).

2. Apparatus according to claim 1 wherein the feed means (9,10) are provided with measuring means (11) for delivering a predetermined quantity of the material to be filled.

3. Apparatus according to claim I or claims 2 wherein the filling means (7,8) are vibratory troughs.

4. Apparatus according to claim 3 wherein control means is provided to operate the vibratory troughs (7,8) for a predetermined time in a filling operation, sufficient to shake the desired quantity of the material down into the sleeves.