Claims
- 1. A method of heating a body of molten aluminum in a crucible to add heat to offset losses encountered during transportation or in holding in the crucible, the method comprising:
- (a) providing a crucible containing a body of molten aluminum, the crucible having:
- (i) a bottom and sides joined together to contain said molten aluminum, said bottom and sides having a liner comprised of a refractory substantially inert to said molten aluminum; and
- (ii) said liner having a series of heating element receptacles provided therein, said receptacles lined with a ceramic tube fabricated from a material selected from the group consisting of mullite, boron nitride, silicon nitride, silicon carbide, silicon aluminum oxynitride, zirconia, stabilized zirconia and mixtures thereof;
- (b) providing an electric heating element in said ceramic tube for heating said liner which transfers heat to said body of molten aluminum; and
- (c) supplying electrical power to said electric heating element and heating said body of aluminum.
- 2. The method in accordance with claim 1 wherein the toner is comprised of a material selected from the group consisting of silicon carbide, silicon nitride, magnesium oxide, spinel, carbon and mixtures thereof.
- 3. The method in accordance with claim 1 wherein said receptacle contains a contact medium for improved conduction of heat from said element to said liner, the contact medium selected from the group consisting of low melting metal and powdered material.
- 4. The method in accordance with claim 3 wherein the contact medium is a low melting point, low vapor pressure metal alloy comprised of a lead-bismuth alloy.
- 5. The method in accordance with claim 3 wherein the contact medium comprises a powdered material selected from the group consisting of silicon carbide, magnesium oxide and carbon having a median particle size in a range of 0.03 to 0.3 mm.
- 6. The method in accordance with claim 1 wherein the ceramic tube is mullite.
- 7. A method of heating a body of molten aluminum in a crucible to add heat to offset losses encountered during transportation or in holding in the crucible, the method comprising:
- (a) providing a crucible containing a body of molten aluminum, the crucible having:
- (i) a bottom and sides joined together to contain said molten aluminum, said bottom and sides having a liner comprised of a refractory substantially inert to said molten aluminum, said liner material comprised of a material selected from the group consisting of silicon carbide, silicon nitride, magnesium oxide, spinel, carbon and mixtures thereof; and
- (ii) said liner having a series of heating element receptacles provided therein, said receptacles lined with a ceramic tube fabricated from a material selected from the group consisting of mullite, boron nitride, silicon nitride, silicon carbide, and silicon aluminum oxynitride;
- (b) providing an electric heating element in said ceramic tube for heating said liner which transfers heat to said body of molten aluminum; and
- (c) supplying electrical power to said electric heating element and heating said body of aluminum.
- 8. An improved crucible for containing a body of molten aluminum and for adding heat to offset thermal losses during transportation, said crucible comprised of:
- (a) a bottom and sides joined together to contain said molten aluminum;
- (b) a liner comprised of a refractory substantially inert to said molten aluminum;
- (c) a series of heating element receptacles provided in said liner, said receptacles lined with a ceramic tube fabricated from a material selected from the group consisting of mullite, boron nitride, silicon nitride, silicon carbide, silicon aluminum oxynitride, zirconia, stabilized zirconia and mixtures thereof; and
- (d) an electric heating element provided in said ceramic tube for transferring heat to the body of aluminum.
- 9. The improved crucible in accordance with claim 8 wherein the liner is comprised of a material selected from the group consisting of silicon carbide, silicon nitride, magnesium oxide, spinel, carbon and mixtures thereof.
- 10. The improved crucible in accordance with claim 8 wherein said receptacle contains a contact medium for improved conduction of heat from said element to said liner, the contact medium selected from the group consisting of low melting metal and powdered material.
- 11. The improved crucible in accordance with claim 10 wherein the contact medium is a low melting point, low vapor pressure metal alloy comprised of a lead-bismuth alloy.
- 12. The improved crucible in accordance with claim 10 wherein the contact medium comprises a powdered material selected from the group consisting of silicon carbide, magnesium oxide and carbon having a median particle size in a range of 0.03 to 0.3 mm.
- 13. The improved crucible in accordance with claim 8 wherein the ceramic tube is mullite.
- 14. An improved crucible for containing a body of molten aluminum and for adding heat to offset thermal losses during transportation, said crucible comprised of:
- (a) a bottom and sides joined together to contain said molten aluminum;
- (b) a liner comprised of a material substantially inert to said molten aluminum, said liner comprised of a material selected from the group consisting of silicon carbide, silicon nitride, magnesium oxide, spinel, carbon and mixtures thereof;
- (c) a series of heating element receptacles provided in said liner, said receptacles lined with a ceramic tube fabricated from a material selected from the group consisting of mullite, boron nitride, silicon nitride, silicon carbide, silicon aluminum oxynitride, zirconia, stabilized zirconia and mixtures thereof; and
- (d) an electric heating element provided in said ceramic tube for transferring heat to the body of aluminum.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 08/937,364, Filed Sep. 25, 1997, U.S. Pat. No. 5,850,073, which is a continuation-in-part of U.S. Ser. No. 08/882,922, Filed Jun. 26, 1997, U.S. Pat. 5,850,072, which is a continuation-in-part of U.S. Ser. No. 08/801,769, filed Feb. 18, 1997, now U.S. Pat. No. 5,894,541, incorporated herein by reference.
US Referenced Citations (36)
Foreign Referenced Citations (3)
Number |
Date |
Country |
1233456 |
Feb 1967 |
DEX |
62-112983 |
May 1987 |
JPX |
60-188792 |
Feb 1989 |
JPX |
Continuation in Parts (3)
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Number |
Date |
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Parent |
937364 |
Sep 1997 |
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Parent |
882922 |
Jun 1997 |
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Parent |
801769 |
Feb 1997 |
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