Atomisation of metals
AssigneeOsprey Metals Limited
InventorsJeffrey S. Coombs, Gordon R. Dunstan
Life of this patent
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Abstract
A device for gas atomising a liquid stream, such as a stream of molten metal or metal alloy, has an atomising device including, for example, an annular opening for receiving the stream. The atomising device is arranged for applying atomising gas to the stream so as to form a spray of atomised particles. At least a part of the atomising gas, and preferably all, is applied by means movable relative to the stream whereby movement is imparted to the spray to achieve improved uniformity or control of deposition by moving the spray either by moving the atomising device with a symmetric gas flow field relative to the stream or by oscillating or rotating a rotor mounted within the atomising device and arranged to produce an asymmetric gas flow field.
Claims23
Apparatus for gas atomising a liquid stream, such as a stream of molten metal or metal alloy, and for controlling the mass distribution of a layer deposited from the atomised stream, the combination comprising:
- an atomising device;
- a plenum chamber forming a part of the atomising device and defining an opening through which the stream may be teemed;
- atomising means communicating with the plenum chamber for forming an atomising gas flow field of predetermined geometry which atomises the stream into a spray of droplets;
- and
- means for moving the atomising gas flow field relative to the stream whereby the application of said movement may impart movement to the spray while the geometry of the atomising gas flow field remains substantially constant,
- the atomising device being annular and the atomising means comprising a plurality of atomising jets in a rotor, the rotor being movable relative to the atomising device.
Apparatus for gas atomising a liquid stream, such as a stream of molten metal or metal alloy, and for controlling the mass distribution of a layer deposited from the atomised stream, the combination comprising:
- an atomising device;
- a plenum chamber forming a part of the atomising device and defining an opening through which the stream may be teemed;
- atomising means communicating with the plenum chamber for forming an atomising gas flow field of predetermined geometry which atomises the stream into a spray of droplets;
- means for moving the atomising gas flow field relative to the stream whereby the application of said movement may impart movement to the spray while the geometry of the atomising gas flow field remains substantially constant;
- and
- control means for controlling the moving means so as to move the spray through a predetermined cycle of movements, the control means comprising a spur gear connecting with a rotor in the atomising device operative to move the rotor relative to the atomising device.
Apparatus for gas atomising a stream and for controlling the deposition conditions of a deposit formed from deposition of the atomised stream, the combination comprising:
- an annular atomising device having a central opening through which the stream may pass;
- a plenum chamber formed within the atomising device;
- means coupled to the atomising device for supporting the atomising device including an inlet path communicating the plenum chamber with an atomising gas source;
- a rotor mounted within the atomising device for movement relative to the atomising device;
- a plurality of atomising gas jet openings formed in the rotor for directing atomising gas onto the stream passing through the opening, the atomising gas jet openings being positioned in a predetermined fixed relationship relatived to one another so as to form an asymmetric atomising gas flow field of predetermined geometry;
- and
- means for moving the rotor relative to the atomising device whereby the asymmetry of the atomising gas flow field imparts movement to the spray with the geometry of the atomising gas flow field remaining substantially constant and whereby the shape and deposition conditions of a formed deposit are controlled.
Apparatus for controlling the mass distribution of a layer deposited on a surface by an atomised stream, the combination comprising:
- a device for forming an asymmetric atomising gas flow field of predetermined geometry which atomises the stream into a spray of droplets comprising a plenum chamber defining an opening through which the stream is teemed and an atomising rotor mounted to communicate with the plenum chamber and including a plurality of jets for directing atomising gas with an asymmetric gas flow field toward the stream to break the stream up into a spray;
- and
- means for moving the rotor about said stream whereby the asymmetry of the gas flow field causes the spray to oscillate.
Apparatus for gas atomising a liquid stream, such as a stream of molten metal or metal alloy, and for controlling the mass distribution of a layer deposited from the atomised stream, the combination comprising:
- an atomising device defining an opening through which the stream may be teemed;
- atomising means for forming an atomising gas flow field of predetermined geometry which atomises the stream into a spray of droplets;
- and means for moving the atomising gas flow field relative to the stream whereby movement may be imparted to the spray whilst the geometry of the atomising gas flow field remains substantially constant.
A method of moving a spray comprising the steps of passing a liquid stream, such as a stream of molten metal or metal alloy, through an atomising device, atomising the stream by the application of an atomisation gas forming an atomising gas flow field of predetermined geometry which atomises the stream into a spray of droplets, and moving the atomising gas flow field relative to the stream during atomisation to impart movement to the spray whilst maintaining the geometry of the atomising gas flow field substantially constant.
Dependencies are inferred from the claim text.