Patent ID: 7077644

Claim:
A gas-fired burner comprising: a burner ring wall enclosing a cylindrical burner space and forming at least one row of burner ports, said cylindrical burner space having a bottom end and a top end; a cylindrical housing wall disposed around said burner ring wall, forming an annular space between said cylindrical housing wall and said burner ring wall, said cylindrical housing wall forming a premixed fuel/air opening in fluid communication with said annular space; an upper annular ring extending from said burner ring wall to said housing wall and a lower annular ring spaced apart from said upper annular ring extending from said burner ring wall to said housing wall, thereby enclosing said annular space; secondary air flow restriction means for controlling flow of secondary air comprising a substantially planar ring disposed within said cylindrical burner space adjacent to said burner ring wall enclosing a centralized secondary air flow space and disposed at a distance vertically below a vertical disposition of said at least one row of burner ports, said substantially planar ring comprising a plurality of ring fingers oriented towards said centralized secondary air flow space; and a multi-finger grate having alternating long and short fingers disposed above said cylindrical housing wall.