Ultrasonic degassing of molten metals
Methods for degassing and for removing impurities from molten metals are disclosed. These methods can include operating an ultrasonic device in a molten metal bath, and adding a purging gas into the molten metal bath in close proximity to the ultrasonic device.
1. An ultrasonic device comprising:
an ultrasonic transducer;
an elongated probe comprising a first end and a second end, the first end attached to the ultrasonic transducer and the second end comprising a tip, wherein the elongated probe consists of a ceramic;
a purging gas delivery system, wherein the purging gas delivery system comprises a purging gas inlet and a purging gas outlet, wherein the purging gas outlet is at the tip of the elongated probe; and
a booster between the ultrasonic transducer and the elongated probe.
2. The ultrasonic device of claim 1 , wherein the ceramic is a Sialon.
3. The ultrasonic device of claim 2 , wherein the elongated probe is generally cylindrical.
4. The ultrasonic device of claim 1 , wherein the elongated probe is a unitary part.
5. The ultrasonic device of claim 1 , wherein the ceramic is silicon carbide.
6. The ultrasonic device of claim 1 , wherein the ultrasonic device comprises two or more elongated probes.
7. The ultrasonic device of claim 1 , wherein the purging gas delivery system comprises a purging gas delivery channel in the elongated probe.
8. The ultrasonic device of claim 1 , wherein the purging gas delivery system is capable of a volumetric flow rate in a range from about 0.1 to about 150 L/min.
9. An ultrasonic device comprising:
an ultrasonic transducer;
a unitary, generally cylindrical, elongated probe comprising a first end and a second end, the first end attached to the ultrasonic transducer and the second end comprising a tip, wherein the elongated probe consists of a ceramic;
a purging gas delivery system, wherein:
the purging gas delivery system comprises a purging gas inlet and a purging gas outlet;
the purging gas delivery system comprises a purging gas delivery channel in the elongated probe; and
the purging gas outlet is at or within about 5 cm of the tip of the elongated probe; and
a booster between the ultrasonic transducer and the elongated probe.
10. The ultrasonic device of claim 9 , wherein the purging gas outlet is at or within about 2 cm of the tip of the elongated probe.
11. The ultrasonic device of claim 9 , wherein the ultrasonic device comprises two or more elongated probes.
12. The ultrasonic device of claim 9 , wherein the purging gas outlet is at or within about 0.5 cm of the tip of the elongated probe.
13. The ultrasonic device of claim 9 , wherein the purging gas delivery system is capable of a volumetric flow rate in a range from about 0.1 to about 150 L/min.