Ultrasonic probes with gas outlets for degassing of molten metals

• US 9,528,167 B2
• Filed: 11/17/2014
• Issued: 12/27/2016
• Est. Priority Date: 11/18/2013
• Status: Active Grant

• Current Assignee: Southwire Company
• Original Assignee: Southwire Company
• Inventors: Rundquist, Victor F.
• Primary Examiner(s): Wyszomierski, George
• Assistant Examiner(s): MCGUTHRY BANKS, TIMA MICHELE
• Application Number:
  US14/542,697
• Publication Number:
  US 20150135901A1
• Time in Patent Office: 771 Days
• US Class Current: 1/1
• CPC Class Codes: B01J 19/10 employing sonic or ultrasonic vibrations
• CPC Class Codes: B01J 2219/0877 Liquid
• CPC Class Codes: B06B 3/00 Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
• CPC Class Codes: B22D 1/002 Treatment with gases C21C7/072, C22B9/05 take precedence
• CPC Class Codes: B22D 1/005 Injection assemblies therefor features relating to gas injection, provided on closures of the sliding gate type B22D41/42; provided on pouring nozzles B22D41/58; provided on closures of the stopper-rod type B22D41/186
• CPC Class Codes: C21C 7/00 Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 treating molten metals during moulding B22D1/00, B22D27/00; remelting ferrous metals C22B
• CPC Class Codes: C22B 15/006 working up of molten copper, e.g. refining
• CPC Class Codes: C22B 19/32 Refining zinc
• CPC Class Codes: C22B 21/06 refining electrolytic refining C25C; C22B21/0046, C22B21/0061 take precedence
• CPC Class Codes: C22B 21/064 using inert or reactive gases C22B21/066 and C22B21/068 take precedence
• CPC Class Codes: C22B 26/22 Obtaining magnesium
• CPC Class Codes: C22B 9/02 Refining by liquating, filtering, centrifuging, distilling, or supersonic wave action including acoustic waves; C22B9/003, C22B9/006, C22B9/05, C22B9/22 take precedence
• CPC Class Codes: C22B 9/026 by acoustic waves, e.g. supersonic waves
• CPC Class Codes: C22B 9/05 Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ
• CPC Class Codes: F27D 27/00 Stirring devices for molten material F27D3/14 takes precedence

Abstract

Ultrasonic probes containing a plurality of gas delivery channels are described, as well as ultrasonic probes containing recessed areas near the tip of the probe. These probes can be used in ultrasonic devices, and the ultrasonic devices can be used in molten metal processing operations to reduce the amount of dissolved gasses and impurities in molten metals.

Claims

1. An ultrasonic device comprising:

an ultrasonic transducer;

an ultrasonic probe attached to the transducer, the probe comprising a tip and two or more gas delivery channels extending through the probe; and

a gas delivery system, the gas delivery system comprising;

a gas inlet,

gas flow paths through the gas delivery channels, and

gas outlets at or near the tip of the probe.

2. The ultrasonic device of claim 1, wherein the probe comprises stainless steel, titanium, niobium, a ceramic, or a combination thereof.

3. The ultrasonic device of claim 1, 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 1, wherein:

the probe comprises a Sialon;

the probe comprises from three to five gas delivery channels; and

the gas outlets are at the tip of the probe.

5. The ultrasonic device of claim 1, wherein the probe is a generally cylindrical elongated probe, and a length to diameter ratio of the elongated probe is in a range from about 5:

1 to about 25;

1.

6. The ultrasonic device of claim 1, wherein the probe is a generally cylindrical elongated probe, and a ratio of the cross-sectional area of the tip of the elongated probe to the cross-sectional area of the gas delivery channels is in a range from about 30:

1 to about 1000;

1.

7. The ultrasonic device of claim 1, wherein the ultrasonic device further comprises a booster between the transducer and the probe, and the gas inlet is in the booster.

8. The ultrasonic device of claim 7, wherein a recessed gas chamber at an end of the booster connects to the gas inlet, the recessed gas chamber configured to direct gas flow to the gas delivery channels.

9. The ultrasonic device of claim 1, wherein the ultrasonic device comprises from two to eight ultrasonic probes.

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 into the gas delivery system, through the gas delivery channels, and into the molten metal bath at a rate for each ultrasonic probe 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, SO₂, 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, SF₆, 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 for each ultrasonic probe in a range from about 1 to about 50 L/min;

the dissolved gas comprises hydrogen;

the molten metal bath comprises aluminum, copper, or a combination thereof;

the purging gas comprises argon, nitrogen, or a combination thereof;

or

any combination thereof.

13. The method of claim 10, wherein:

the impurity comprises sodium, and an amount of sodium in the molten metal bath is reduced to less than 1 ppm; and

/or

an amount of total inclusions, in mm²/kg, in the molten metal bath is reduced by at least about 50%.

14. The method of claim 10, wherein the method comprises operating from two to sixteen ultrasonic devices in the molten metal bath.

15. An ultrasonic device comprising:

an ultrasonic transducer;

an ultrasonic probe attached to the transducer, the probe comprising a tip, a gas delivery channel extending through the probe, and a recessed region near the tip of the probe; and

a gas delivery system, the gas delivery system comprising;

a gas inlet,

a gas flow path through the gas delivery channel, and

a gas outlet at or near the tip of the probe;

wherein the probe is a generally cylindrical elongated probe, and a ratio of a total length of the recessed regions to a length of the elongated probe is in a range from about 10;

1 to about 100;

1.

16. The ultrasonic device of claim 15, wherein the probe comprises stainless steel, titanium, niobium, a ceramic, or a combination thereof.

17. The ultrasonic device of claim 15, further comprising a gas outlet in a recessed region.

18. The ultrasonic device of claim 15, wherein

the probe comprises a Sialon;

the probe comprises from two to five recessed regions; and

at least one gas outlet is at the tip of the probe.

19. The ultrasonic device of claim 15, wherein:

the probe is a generally cylindrical elongated probe, and a length to diameter ratio of the elongated probe is in a range from about 5;

1 to about 25;

1; and

a ratio of the cross-sectional area of the tip of the elongated probe to the cross-sectional area of the gas delivery channel is in a range from about 30;

1 to about 1000;

1.

20. The ultrasonic device of claim 15, wherein the ultrasonic device further comprises a booster between the transducer and the probe, and the gas inlet is in the booster.

21. 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 15 in the molten metal bath; and

(b) introducing a purging gas into the gas delivery system, through the gas delivery channel, and into the molten metal bath at a rate for each ultrasonic probe in a range from about 0.1 to about 150 L/min.

22. The method of claim 21, wherein:

the purging gas is introduced into the molten metal bath at a rate for each ultrasonic probe in a range from about 1 to about 50 L/min;

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, SF₆, chlorine, or a combination thereof;

or

any combination thereof.

23. An ultrasonic device comprising:

an ultrasonic transducer;

an ultrasonic probe attached to the transducer, the probe comprising a tip, a gas delivery channel extending through the probe, and a recessed region near the tip of the probe; and

a gas delivery system, the gas delivery system comprising;

a gas inlet,

a gas flow path through the gas delivery channel, and

a gas outlet at or near the tip of the probe;

wherein a diameter of the recessed region is from about 75 to about 85% of the diameter of the probe.