Claims
- 1. A method of reducing CO gas emissions when operating a vertical shaft furnace for melting non-ferrous metals, said furnace having a melting chamber, burners in the melting chamber and a charge opening in the shaft of the furnace above the melting chamber for charging metal to the melting chamber comprising the steps of:
- charging the melting chamber with a non-ferrous metal charge;
- combusting a fuel in the burners to melt the metal charge, the combustion of said fuel generating emission gases including CO gas;
- preheating a quantity of air; and
- forcing a quantity of said preheated air into the shaft of the furnace above the melting chamber and burners at a first location immediately below the charge opening to burn a substantial portion of the CO gas generated in the melting chamber.
- 2. The method of claim 1, wherein said air is preheated to a temperature of from about 400.degree. F. to about 900.degree. F.
- 3. The method of claim 2, wherein said air is forced into said shaft at a flow rate of about 600 ft..sup.3 /min. to about 900 ft..sup.3 /min.
- 4. The method of claim 1, including the step of introducing air under pressure into the shaft above the charge opening to increase the pressure in the shaft.
- 5. The method of claim 1, wherein said non-ferrous metal includes copper, aluminum and alloys thereof.
- 6. The method of claim 1, including the step of operating said furnace with a reducing atmosphere in the melting chamber.
- 7. The method of claim 1, wherein said preheating step includes the steps of drawing ambient air into a plenum adjacent the furnace shaft and heating the ambient air in said plenum.
- 8. The method of claim 1, wherein said forcing step includes the step of flowing pressurized air through openings in a wall of the shaft of the furnace.
- 9. The method of claim 1, including the step of forcing a second quantity of air into the shaft of the furnace at a second location above the charge opening in a downward direction to inhibit upward flow of combustion gases and thereby restrict air dilution and cooling of the combustion gases.
- 10. The method of claim 9, wherein said second quantity of air is ambient air.
- 11. The method of claim 9, including the step of directing the second quantity of air downwardly toward the first location.
- 12. The method of claim 9, wherein said second quantity of air is forced into the shaft of the furnace only when the charge opening is open.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional application of co-pending application U.S. Ser. No. 08/143,026 filed Oct. 29, 1993, now U.S. Pat. No. 5,397,109.
US Referenced Citations (4)
Divisions (1)
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Number |
Date |
Country |
Parent |
143026 |
Oct 1993 |
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