GB2046153A

GB2046153A - Arrangement for The Cleaning of Tapping Pots

Info

Publication number: GB2046153A
Application number: GB8011497A
Authority: GB
Original assignee: Elkem Spigerverket AS
Current assignee: Elkem ASA
Priority date: 1979-04-06
Filing date: 1980-04-08
Publication date: 1980-11-12
Also published as: NO147940B; NO147940C; NL8001947A; AU5723580A; ES8101957A1; FI800868A; ES490230A0; IT1131039B; DE3012410A1; YU93780A; JPS55133867A; GB2046153B; BR8001914A; ZA801481B; IT8020861A0; AU518121B2; SE8002411L; FR2452989A1; NO791156L; PL223259A1

Abstract

The invention provides an arrangement for removal of slag and metal remainders 5 from pots 3 which are used for the tapping of molten material and especially of molten aluminium and aluminium alloys, comprising a rotatable, vertically displaceable milling cutter 1 which is arranged on a shaft 7 and equipped with a number of cutters 2 distributed around the circumference of the milling cutter and so arranged that they will cut away deposited remainders 5 on the side wail of the pot and on its bottom, the pot being arranged bottom upwards on a ring 5 which is arranged to rotate in opposite direction of the direction of rotation of the milling cutter, the milling cutter and the pot being arranged eccentrically in relation to one another. <IMAGE>

Description

SPECIFICATION Arrangement for the Cleaning of Tapping Pots The invention relates to an arrangement for the cleaning of those pots which are used for tapping of molten metal and has particularly for its object to remove slag and metal remainders from pots which have been used by tapping of aluminium and aluminium alloys, but it can also be used for instance within the iron and steel industry.

Up till now the removal of deposited slag and metal remainders from such tapping pots has been effected manually i.e. by means of bars and sledge or by compressed air equipment. This labour is very hard and inconvenient to carry out, and because of the manual operation the refractory lining of the pots are easily damaged and also destroyed, and the pots must be relined regularly.

Accordingly the present invention provides an arrangement for removal of slag and metal remainders from pots which are used for the tapping of molten material and especially of molten aluminium and aluminium alloys comprising a rotatable, vertically displaceable milling cutter which is arranged on a shaft and equipped with a number of cutters distributed around the circumference of the milling cutter and so arranged that they will cut away deposited remainders on the side wall of the pot and on its bottom, the pot being arranged bottom upwards on a ring which is arranged to rotate in opposite direction of the direction of rotation of the milling cutter, the milling cutter and the pot being arranged eccentrically in relation to one another.

By the arrangement according to the invention the lining is preserved and there is obtained an important reduction of the number of relinings per pot, while labour employed is reduced. It may be mentioned that a plant which previously had about 33 relinings per pot every year, by employment of the arrangement according to the invention will be able to reduce this to about 5 relinings per year. The arrangement also carries with it that less labour is needed for the cleaning of the pots and it has turned out that it is possible to save 75% of the crew. Another advantage by the invention is that the pots can be cleaned in cold or hot state. The conditions at the plant will also be considerably improved as the cleaning of the pots takes place within the enclosed space and the material may fall straight down into a waste container.

The pot and the milling cutter are arranged eccentrically in relation to each other by arranging either the milling cutter and its shaft or the pot eccentrically in relation to the outer surroundings of the equipment.

In order to promote a fuller understanding of the above and other aspects of the present invention, an embodiment will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 shows an embodiment of the invention before the starting of the operation, i.e.

when the pot has been arranged in correct position, but before the milling operation is started.

Figure 2 shows the arrangement of Figure 1 by the end of the cleaning operation.

In the embodiment shown in the Figures, 1 indicates a milling cutter which is equipped with a number of cutters 2 which are distributed along the circumference of the milling cutter. As shown the cutters are so shaped that they may cut deposits on the inner wall of the pot as well as on its bottom. The pot is shown at 3 with a refractory lining 4, and in Figure 1 those remainders of metal and slag which are to be removed from the pot are indicated by 5. The cutting operation is usually so adjusted that there will be left a thin layer 6 of remainders as indicated in Figure 2.

This layer which may be about 10 mm thick contributes to protect the lining and thus to prolong the life of the pot. The milling cutter 1 is mounted on a shaft 7 which is carried on a tubular body 9. The milling cutter is rotated by means of a motor which is schematically indicated at 8. The shaft 7 and the tubular body 9 are carried in an outer housing 10, and a number of guide members with appurtening rails are located between the tubular body 9 and the housing 1 0.

These guiding elements which are not shown on the drawings provide that the milling cutter always is in correct position. The milling cutter 2 with its shaft 7 and the tubular body 9 can be fed up and down by means of lead screws 11 and 12 which cooperate with nuts 13 and 14 on the body 9 and which can be made of suitable selflubricating material. The nuts 13 and 14 must be supplied with pressurized air in order to keep dust out of them and prevent jamming on the lead screws. The lead screws are driven by the motors 1 8 and synchronized by the chain 19.

The pot 3 is located in a bottom-up position on a rotatable ring 1 5 in known way.

As mentioned above the pot is arranged eccentrically in relation to the axis of the milling cutter 1 and the ring 1 5 is rotated in the opposite direction of the milling cutter. By arranging the milling cutter 1 with its shaft 7 and the tubular body 9 eccentrically in relation to the housing 10 which is cylindrical there is obtained a shorter supporting distance between the tubular body 9 and the housing 10. The ring 1 5 with the pot 3 must then be arranged concentricaily in relation to the housing 10.

When the pot 3 has been rigidly mounted on the ring 15, the ring 1 5 is driven to give a slow rotation. The drive arrangement for the ring 1 5 is not shown. Simultaneously rotation of the milling cutter is started and also its upwardly directed motion. The two rotation speeds and the upwardly directed speed must of course be adjusted according to each other so that optimum results are obtained. In operation of the arrangement excellent results are obtained with a rotation speed of the milling cutter of 100 rpm, while the rotation speed of the pot was 1-2 rpm.

The motion upwards was at a rate of up to 12 cm/min.

The complete equipment is as mentioned above surrounded by a housing 10, and the material which is removed from the pot falls down into a container 16, which is removed when it is full. The lower part of the housing 10 and the waste bin 1 6 is surrounded by screens or similar arrangement 1 7 which prevents the dust, etc.

from escaping into the surroundings. The complete system can also be reduced to a pressure slightly below atmospheric so that the operation is completely dust free.

The figures show a pot with cylindrical walls, but it is of course also possible to clean pots with other shapes for instance conical shapes with oblique side walls, as the shape of the milling cutter can then be adjusted in accordance with the shape of the pot.

The cleaning operation can as mentioned above be carried out on cold as well as on hot pots. All operations can be remotely controlled from a control board. All motions can be carried out by means of hydraulic motors supplied from a central pump unit, but electric motors may be used also.

Claims

1. An arrangement for removal of slag and metal remainders from pots which are used for the tapping of molten material and especially of molten aluminium and aluminium alloys, comprising a rotatable, vertically displaceable milling cutter which is arranged on a shaft and equipped with a number of cutters distributed around the circumference of the milling cutter and so arranged that they will cut away deposited remainders on the side wall of the pot and on its bottom, the pot being arranged bottom upwards on a ring which is arranged to rotate in opposite direction of the direction of rotation of the milling cutter, the milling cutter and the pot being arranged eccentrically in relation to one another.

2. An arrangement as claimed in Claim 1, in which the milling cutter with its shaft is carried on a tubular body, the shaft and the tubular body being disposed in an outer housing and guided in relation to the housing by means of a number of guiding elements operative between the tubular body and the housing.

3. An arrangement as claimed in Claim 1 or 2, in which the vertical movement of the milling cutter with its shaft is effected by means of a lead screw arrangement.

4. An arrangement as claimed in Claim 2 or 3, in which the outer housing surrounds the shaft of the cutter, the tubular body and the lead screw arrangement.

5. An arrangement as claimed in Claim 2, 3 or 4, in which screens are provided which surround the lower part of the housing and a container for collection of the waste material cut by the cutter.

6. An arrangement for the removal of slag and metal remainders from tapping pots, substantially as herein described with reference to the accompanying drawings.