Process of using a submerged combustion melter to produce hollow glass fiber or solid glass fiber having entrained bubbles, and burners and systems to make such fibers

A method of operating a submerged combustion melter for melting a glass-forming material, the method comprising:

• providing the submerged combustion melter comprising a melt chamber having an interior at least partially defined by a melt chamber floor, at least one melt chamber sidewall, and a melt chamber roof;
• disposing, in the interior of the melt chamber, the glass-forming material;
• disposing, in the melt chamber floor, a submerged combustion burner;
• introducing, to the submerged combustion burner, a first fluid via a first conduit disposed in the submerged combustion burner wherein the first conduit defines a longitudinal axis of the submerged combustion burner, and wherein the first conduit terminates at a body of the submerged combustion burner that defines a connector section and an angled section, wherein the connector section is aligned with the longitudinal axis and couples the first conduit to the angled section, wherein the angled section is disposed at a first angle to the longitudinal axis;
• introducing, to the submerged combustion burner, a second fluid via a second conduit disposed in the submerged combustion burner, wherein the second conduit is parallel to the longitudinal axis and terminates at and is fluidically coupled to one of a plurality of non-central passages defined by the body, wherein the plurality of non-central passages are disposed at a second angle to the longitudinal axis;
• introducing, to the submerged combustion burner, a third fluid via a plurality of third conduits disposed in the submerged combustion burner, wherein the plurality of third conduits are discrete from and surround the second conduit and comprise a first portion parallel to the longitudinal axis and a second portion disposed at a third angle to the longitudinal axis;
• mixing the first fluid with the second fluid and the third fluid in a mixing region to form a mixture of the first fluid and the second fluid and the third fluid, wherein the mixing region is at least partially defined by an outermost surface of the burner, wherein a discharge opening of one of the plurality of third conduits into the mixing region is disposed at a first distance from the longitudinal axis;
• introducing, to a melt region of the submerged combustion melter, a mixture of the first fluid and the second fluid and the third fluid;
• and
• substantially simultaneously with introducing the mixture of the first fluid and the second fluid and the third fluid, circulating concentrically around the first conduit, the second conduit, and the third conduit, a cooling fluid, wherein the cooling fluid is circulated in a cooling volume having an innermost distance from the longitudinal axis less than the first distance, and wherein the cooling volume separates adjacent third conduits of the plurality of third conduits.