Apparatus, systems and methods for conditioning molten glass

Channel apparatus for use with submerged combustion systems and methods of use to produce glass. One channel apparatus includes a flow channel defined by a floor, a roof, and a wall structure connecting the floor and roof, the flow channel divided into sections by a series of skimmers. Channel apparatus include both high and low momentum combustion burners, with one or more high momentum combustion burners positioned immediately upstream of each skimmer in either the roof or sidewall structure, or both, and one or more low momentum combustion burners positioned immediately downstream of each skimmer in either the roof, the sidewall structure, or both, and positioned to transfer heat to the molten mass of glass without substantial interference from foamed material. Certain embodiments include increased height of glass-contact refractory, in particular immediately upstream of the skimmers.