The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 12, 1977
Filed:
Sep. 04, 1975
Steve Douglas Sanford, Richmond, IN (US);
Vaughn Charles Chenoweth, Hollanburg, OH (US);
Duane Harold Faulkner, Cambridge City, IN (US);
Johns-Manville Corporation, Denver, CO (US);
Abstract
A two-stage orifice outlet is provided for an electric furnace. The structure defining the inner orifice adjacent the interior of the furnace through which molten material passes in its initial stages of withdrawal from the furnace is made of a refractory metal to withstand the high temperatures present within the furnace and this refractory metal must be protected from the oxidizing effects of air. The outer structure defining the outer orifice is made from a more oxidation resistant material and acts as a shield to prevent the oxidation of the refractory metal inner orifice. The outer orifice is maintained below a temperature at which it will undergo rapid deterioration by the use of cooling means. The outlet described above is operated without injecting neutral or reducing gases into the area surrounding the furnace outlet as was required by prior art furnaces of this type.