Abstract: Apparatus for improving oxygen burner performance in a glass furnace having a chamber with a bottom wall connected to a roof wall by side walls, said walls having refractory surfaces, and an opening in the roof wall, comprises a burner for injecting a flame downwardly into the chamber through the roof opening with the flame being adapted to impinge against a bath of molten glass on the bottom wall of the chamber, a hopper for inserting a shower of cullet into the chamber through the roof opening, and a burner spout having a flared end for forming the shower of cullet into a shroud around the flame and for heating the shower of cullet and for forming the cullet into an annular ridge of unmelted cullet on the top surface of the molten glass bath, whereby said ridge deflects the flame upwardly when the flame bounces from the bath of molten glass so that the flame does not bounce horizontally and impinge against the near surface of the side walls, and the shower of cullet shrouds the flame and protects the furnac