Ultrasonic device with integrated gas delivery system
View Patent ↗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 through the tip of the ultrasonic device.
1. An ultrasonic device comprising:
an ultrasonic transducer;
an elongated probe attached to the ultrasonic transducer, the probe comprising a tip; and
a gas delivery system, the gas delivery system comprising:
a gas inlet,
a gas flow path through the probe, and
a gas outlet at the tip of the probe;
wherein:
the probe comprises a ceramic; and
a length to diameter ratio of the probe is in a range from about 5:1 to about 25:1.
2. The ultrasonic device of claim 1 , wherein the probe is a unitary part.
3. The ultrasonic device of claim 2 , wherein the probe comprises a Sialon, a Silicon carbide, a Boron carbide, a Boron nitride, a Silicon nitride, an Aluminum nitride, an Aluminum oxide, a Zirconia, or a combination thereof.
4. The ultrasonic device of claim 2 , wherein the probe comprises a Sialon.
5. The ultrasonic device of claim 1 , wherein the probe is secured to the ultrasonic transducer with an attachment nut.
6. The ultrasonic device of claim 1 , wherein the probe has a radius of curvature of at least about ½-inch on an attachment side of the probe.
7. The ultrasonic device of claim 1 , wherein:
the probe comprises a Sialon;
the probe is generally cylindrical; and
the ultrasonic device further comprises a booster between the ultrasonic transducer and the probe.
8. The ultrasonic device of claim 7 , wherein the length to diameter ratio is in a range from about 7:1 to about 22:1.
9. The ultrasonic device of claim 7 , wherein a ratio of the cross-sectional area of the tip of the probe to the cross-sectional area of the gas outlet is in a range from about 60:1 to about 750:1.
10. A method for reducing an amount of a dissolved gas and/or an impurity in a molten metal bath, the method comprising:
(a) operating the ultrasonic device of claim 1 in the molten metal bath; and
(b) introducing a purging gas through the gas delivery system and into the molten metal bath at a rate in a range from about 0.1 to about 150 L/min.
11. The method of claim 10 , wherein:
the dissolved gas comprises oxygen, hydrogen, sulfur dioxide, or a combination thereof;
the impurity comprises an alkali metal;
the molten metal bath comprises aluminum, copper, zinc, steel, magnesium, or a combination thereof;
the purging gas comprises nitrogen, helium, neon, argon, krypton, xenon, chlorine, or a combination thereof; or
any combination thereof.
12. The method of claim 10 , wherein the purging gas is introduced into the molten metal bath at a rate in a range from about 10 to about 500 mL/hr of purging gas per kg/hr of output from the molten metal bath.
13. The method of claim 10 , wherein:
the dissolved gas comprises hydrogen;
the molten metal bath comprises aluminum, copper, or a combination thereof; and
the purging gas comprises argon, nitrogen, or a combination thereof.
14. An ultrasonic device comprising:
an ultrasonic transducer;
an elongated probe comprising a tip;
a booster between the ultrasonic transducer and the elongated probe; and
a gas delivery system, the gas delivery system comprising:
a gas inlet in the booster,
a gas flow path through the probe, and
a gas outlet at the tip of the probe;
wherein:
the probe comprises a ceramic; and
a length to diameter ratio of the probe is in a range from about 5:1 to about 25:1.
15. The ultrasonic device of claim 14 , wherein the probe comprises a Sialon, a Silicon carbide, a Boron carbide, a Boron nitride, a Silicon nitride, an Aluminum nitride, an Aluminum oxide, a Zirconia, or a combination thereof.
16. The ultrasonic device of claim 14 , wherein the probe is a unitary, generally cylindrical probe comprising a Sialon.
17. The ultrasonic device of claim 16 , wherein the probe is secured to the ultrasonic transducer with an attachment nut.
18. The ultrasonic device of claim 16 , wherein:
a ratio of the cross-sectional area of the tip of the probe to the cross-sectional area of the gas outlet is in a range from about 60:1 to about 750:1; and
the length to diameter ratio is in a range from about 7:1 to about 22:1.
19. A method for reducing an amount of a dissolved gas and/or an impurity in a molten metal bath, the method comprising:
(a) operating the ultrasonic device of claim 14 in the molten metal bath; and
(b) introducing a purging gas through the gas delivery system and into the molten metal bath.
20. The method of claim 19 , wherein:
the dissolved gas comprises oxygen, hydrogen, sulfur dioxide, or a combination thereof;
the molten metal bath comprises aluminum, copper, zinc, steel, magnesium, or a combination thereof; and
the purging gas comprises nitrogen, helium, neon, argon, krypton, xenon, chlorine, or a combination thereof.
21. The method of claim 19 , wherein:
the dissolved gas comprises hydrogen;
the molten metal bath comprises aluminum, copper, or a combination thereof; and
the purging gas comprises argon, nitrogen, or a combination thereof.
22. The method of claim 19 , wherein the purging gas is introduced into the molten metal bath at a rate in a range from about 1 to about 50 L/min.
23. An ultrasonic device comprising:
an ultrasonic transducer;
an elongated probe comprising a tip;
a booster between the ultrasonic transducer and the elongated probe; and
a gas delivery system, the gas delivery system comprising:
a gas inlet in the booster,
a gas flow path through the probe, and
a gas outlet at the tip of the probe;
wherein a length to diameter ratio of the probe is in a range from about 5:1 to about 25:1.
24. The ultrasonic device of claim 23 , wherein the probe comprises stainless steel, titanium, niobium, a ceramic, or a combination thereof.
25. The ultrasonic device of claim 23 , wherein the probe comprises a Sialon.
26. The ultrasonic device of claim 23 , wherein:
a ratio of the cross-sectional area of the tip of the probe to the cross-sectional area of the gas outlet is in a range from about 60:1 to about 750:1; and
the length to diameter ratio is in a range from about 7:1 to about 22:1.
27. A method for reducing an amount of a dissolved gas and/or an impurity in a molten metal bath, the method comprising:
(a) operating the ultrasonic device of claim 23 in the molten metal bath; and
(b) introducing a purging gas through the gas delivery system and into the molten metal bath at a rate in a range from about 0.1 to about 150 L/min.