MELTING KILN, MELTING METHOD, METHOD OF MANUFACTURING ALKALI-FREE GLASS, AND ALKALI-FREE GLASS

摘要

PROBLEM TO BE SOLVED: To provide a melting kiln capable of efficiently heating a molten glass through a foam layer and also suppressing BOin the molten glass from vaporizing.SOLUTION: There are provided a melting kiln, a melting method, and a method of manufacturing an alkali-free glass such that the melting kiln is configured to melt a raw material 12 of alkali-free glass containing 54-73 mass% of SiOand 0.1-12 mass% of BO, and comprises a first chamber 21 into which the raw material 12 is fed, a first chamber burner 26, a second chamber 31 into which a molten glass 14 is supplied from the first chamber 21, a second chamber burner 36, and a throat 41 which connects a lower part of the first chamber 21 with a lower part of the second chamber 31, wherein an oxygen combustion burner and an air combustion burner are used as the first chamber burner 26 and second chamber burner 36, 50-100% of total combustion heating value per hour of all first chamber burners 26 being by oxygen combustion burners, and 75-100% of total combustion heating value per hour of all second chamber burners 36 being by air combustion burners.SELECTED DRAWING: Figure 2