Spencer & Frank
Method of manufacturing glass
 A method for manufacturing glass by melting a batch of raw material in a melting chamber of a continuous glass-melting tank furnace, permitting the glass to flow through a rising passageway and a sill provided by the furnace to a separate refining chamber in the furnace, the atmospheres in the melting and refining chambers being isolated, and heating the glass at the upstream end of the refining chamber to a higher temperature than that of the glass over the sill so that the glass leaving the sill plunges into the refining chamber and is precluded from forming a return current to the melting chamber. 
Asahi Glass Co. Ltd.
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C03B C03B C03B Y02P C03B C03B
inventional inventional inventional additional inventional inventional
Motoharu
Kurata