Cooling system for post-mixed burner

Claim 1

A burner comprising: (a) a fuel tube having its discharge end at the burner face; (b) an annular oxidant passageway circumferentially around said fuel tube and axially along said fuel tube to a point short of the burner face so as to define a space between said point and the burner face; (c) a plurality of oxidant passages passing through said defined space, connected to and communicating with said annular oxidant passageway at said point and having their discharge end at the burner face; (d) a second annular passageway circumferentially around said fuel tube and extending axially along said fuel tube into said defined space, adapted for flow for cooling fluid and positioned between said fuel tube an said annular oxidant passageway; (e) a third passageway circumferentially around both said fuel tube and said oxidant passageway, extending into said defined space and adapted for flow of cooling fluid; (f) at least one connecting conduit, connecting said second and third annular passageways at their respective points most proximate the burner face, in said defined space; (d) a thick solid portion between the burner face and said connecting conduit(s), having a thickness sufficient to provide a seat to accomodate a directional removable nozzle, said thickness being at least twice the thickness of the outermost passageway wall; (h) a metallic removable directional nozzle at the discharge end of at least one oxidant passage, said directional nozzle having a length greater than the greatest width of its opening and a forth passageway circumferentially around said fuel tube and positioned between said fuel tube and said second annular passageway, said forth passageway extending to the burner face for supplying oxidant.