Treatment of molten light metals and apparatus
First Claim
1. Apparatus for treating molten metal comprising in combination:
- (a) a heated vessel having inlet and outlet means for the continuous flow of said metal downwardly through said vessel,(b) a perforated plate extending horizontally across said vessel dividing said vessel into an upper treatment section and a lower treatment section, said plate comprising an intermediate treatment section, and(c) a device for injecting gas in the form of small discrete bubbles into said metal in said lower treatment section, said device comprising a hollow rotatable shaft extending downwardly through an opening in said plate with drive means coupled to the upper end of said shaft, a vaned rotor fixedly attached to the lower end of said shaft within said lower treatment section, with one or more passageways within said rotor for conducting said gas from the interior of said shaft to said metal in said lower treatment section, whereby upon rotation of said rotor and provision of said gas flow, said gas is injected into said metal in the form of small discrete bubbles which move away from the rotor and are uniformly dispersed within the lower treatment section.
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Accused Products
Abstract
An apparatus and process are described for treating molten metal. The invention comprises: (a) a heated vessel having inlet and outlet means for the continuous flow of molten metal downwardly through the vessel, (b) a perforated plate extending horizontally across the vessel dividing it into an upper treatment section and a lower treatment section, this plate forming an intermediate treatment section, and (c) a device for injecting gas in the form of small discrete bubbles into the metal in the lower treatment section, this device comprising a hollow rotatable shaft extending downwardly through an opening in the plate with drive means coupled to the upper end of the shaft, a vaned rotor fixedly attached to the lower end of the shaft within the lower treatment section, with one or more passageways within the rotor for conducting gas from the interior of the shaft to the metal in the lower treatment section. When the gas is discharged through the rotor and the rotor is rotated, the gas is injected into the metal in the form of small discrete bubbles which are uniformly dispersed within the lower treatment section. In a preferred embodiment of the invention the gas bubbles move from the rotor upwardly and outwardly in a generally conical pattern to be distributed across the bottom of the perforated plate and pass upwardly through the perforations thereof.
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Citations
25 Claims
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1. Apparatus for treating molten metal comprising in combination:
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(a) a heated vessel having inlet and outlet means for the continuous flow of said metal downwardly through said vessel, (b) a perforated plate extending horizontally across said vessel dividing said vessel into an upper treatment section and a lower treatment section, said plate comprising an intermediate treatment section, and (c) a device for injecting gas in the form of small discrete bubbles into said metal in said lower treatment section, said device comprising a hollow rotatable shaft extending downwardly through an opening in said plate with drive means coupled to the upper end of said shaft, a vaned rotor fixedly attached to the lower end of said shaft within said lower treatment section, with one or more passageways within said rotor for conducting said gas from the interior of said shaft to said metal in said lower treatment section, whereby upon rotation of said rotor and provision of said gas flow, said gas is injected into said metal in the form of small discrete bubbles which move away from the rotor and are uniformly dispersed within the lower treatment section. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A process for treating molten metal comprising the steps of:
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(a) passing a stream of molten metal downwardly through a heated refractory vessel containing an upper quiescent zone, an intermediate flow modifying zone in the form of a perforated plate extending horizontally across the vessel and a lower turbulent zone, (b) providing a gas injection device submerged in the molten metal in the lower turbulent zone comprising a hollow vertical drive shaft extending through said perforated plate with a vaned rotor fixedly attached to the lower end thereof and gas discharge passageways connecting the hollow portion of the drive shaft to openings between the rotor vanes, (c) introducing a gas into the upper end of the hollow drive shaft under sufficient pressure to be injected in to the molten metal between the rotor vanes, (d) sub-dividing the gas into small discrete bubbles by rotating the vaned rotor at a speed sufficient to create a circulation pattern in the molten metal such that the gas bubbles are transported away from said rotor and are uniformly dispersed within the lower treatment section. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25)
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Specification