GLASS MELTING FURNACE, PROCESS FOR MODIFYING GLASS MELT, PROCESS FOR PRODUCING GLASS MELT, PROCESS FOR PRODUCING GLASS PRODUCT, AND APPARATUS FOR PRODUCING GLASS PRODUCT

摘要

Objective of the present invention is to provide a glass melting furnace, a process for modifying a glass melt and a process for producing glass melt, whereby composition-modified glass melt containing an additive component at a high concentration can be produced with an excellent quality. The glass melting furnace 10 of the present invention is a glass melting furnace 10 for adding an additive to a molten state glass to form composition-modified glass melt, discharging the composition-modified glass melt, and a forehearth 20, said forehearth comprising a feed portion to feed an additive, and a heating means to form a heating gas phase portion above the liquid surface of the glass melt to convert the additive from the feed portion into melted particles of additive below the feed portion.