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US 5,846,479 AGranted
Apparatus for de-gassing molten metal
AssigneeCast House Technology Ltd.
InventorChristopher John English
Life of this patent
Estimating the term…
Abstract
Argon injection nozzles are provided in a close-spaced series lengthwise along a treatment trough, in which liquid aluminum is conveyed. The gas is blown in at high Reynolds No, whereby the jets break up into small bubbles. A high average bubble population density is achieved over the whole volume of liquid metal in the treatment trough. De-gassing is achieved in a metal residence time of 15 to 60 seconds, whereby the trough in which treatment takes place can be small.
Claims34
Apparatus for de-gassing molten metal, wherein:
- the apparatus includes a treatment-trough, made of refractory material, and a means for defining a gas-tight sealed treatment zone, in the treatment-trough;
- the apparatus includes a flow of liquid metal through the treatment-trough, and through the treatment-zone;
- the treatment-trough is trough-shaped, in that the length of the treatment-zone in the treatment-trough is longer than the width and height of the treatment-trough;
- the treatment-trough is provided with a plurality of nozzles, and the nozzles are fixed into the material of the treatment-trough;
- the apparatus includes a flow of treatment-gas through the nozzles;
- the flow of treatment-gas through the nozzles is of such high speed that the treatment-gas breaks up into streams of small bubbles in the liquid metal;
- the nozzles comprise each a respective discrete, single, orifice, and the nozzles are physically separated from each other;
- the nozzles are disposed in line, in a series, lengthwise along the length of the treatment-trough, and are so spaced as to create a bubble-filled zone in the liquid metal in the treatment-zone, along the length of the trough;
- the treatment-trough comprises left and right side-walls, and a floor, and the nozzles are located in at least one of the side-walls, adjacent to the junction of that wall with the floor;
- and the nozzles are so directed that the jets emerge from the nozzles within about +/-15 degrees of horizontal.
7 more elements
Method for de-gassing molten metal, comprising the steps of,
- providing a treatment-trough, made of refractory material, and a means for defining a gas-tight sealed treatment zone, in the treatment-trough;
- providing a flow of liquid metal through the treatment-trough, and through the treatment-zone;
- providing the treatment-trough as trough-shaped, in that the length of the treatment-zone in the treatment-trough is longer than the width and height of the treatment-trough;
- providing the treatment-trough with a plurality of nozzles, the nozzles being fixed into the material of the treatment-trough;
- providing a flow of treatment-gas through the nozzles, of such high speed that the treatment-gas breaks up into streams of small bubbles in the liquid metal;
- wherein the nozzles comprise each a respective discrete, single, orifice, and the nozzles are physically separated from each other;
- disposing the nozzles in line, in a series, lengthwise along the length of the treatment-trough, and so spacing the nozzles as to create a bubble-filled zone in the liquid metal in the treatment-zone, along the length of the trough;
- wherein the treatment-trough comprises left and right sidewalls, and a floor;
- locating the nozzles in at least one of the side-walls, adjacent to the junction of that wall with the floor;
- and so directing the nozzles that the jets emerge from the nozzles within about +/-15 degrees of horizontal.
7 more elements
Dependencies are inferred from the claim text.