Nozzle structure for hydrogen gas burner apparatus

Abstract

The present disclosure provides a nozzle structure for a hydrogen gas burner apparatus capable of reducing an amount of generated NOx. A nozzle structure for a hydrogen gas burner apparatus includes an outer tube and an inner tube concentrically disposed inside the outer tube. The inner tube is disposed so that an oxygen-containing gas is discharged from an opened end of the inner tube in an axial direction of the inner tube. The outer tube extends beyond the opened end of the inner tube in the axial direction of the inner tube so that a hydrogen gas passes through a space between an inner circumferential surface of the outer tube and an outer circumferential surface of the inner tube.

What is claimed is: 
     
         1 . A nozzle structure for a hydrogen gas burner apparatus, comprising an outer tube and an inner tube concentrically disposed inside the outer tube, wherein
 the inner tube is disposed so that an oxygen-containing gas is discharged from an opened end of the inner tube in an axial direction, and   the outer tube extends beyond the opened end of the inner tube in the axial direction so that a hydrogen gas passes through a space between an inner circumferential surface of the outer tube and an outer circumferential surface of the inner tube and proceeds along an outer periphery of the oxygen-containing gas, thereby suppressing contact between and mixture of the oxygen-containing gas and the hydrogen gas,   wherein the oxygen-containing gas is air, and   a ratio Va/Vh between an air flow velocity Va and a hydrogen flow velocity Vh is in a range of greater than or equal to  0 . 1  and less than or equal to 3.0.   
     
     
         2 . The nozzle structure for a hydrogen gas burner apparatus according to  claim 1 , further comprising:
 an oxygen-containing gas blowing duct configured to blow out the oxygen-containing gas in the axial direction and make the oxygen-containing gas pass through a space inside the inner tube; and   a hydrogen gas blowing duct configured to blow out the hydrogen gas into the space between the inner circumferential surface of the outer tube and the outer circumferential surface of the inner tube in the axial direction, and make the hydrogen gas pass through between the inner circumferential surface of the outer tube and the outer circumferential surface of the inner tube, wherein   the oxygen-containing gas blowing duct has a circular shape, and   the hydrogen gas blowing duct has an annular shape so as to surround the oxygen-containing gas blowing duct.   
     
     
         3 . The nozzle structure for a hydrogen gas burner apparatus according to  claim 1 , wherein in a section between the opened end of the inner tube and a base part thereof, a fin that extends in the axial direction while protruding toward the inner tube is provided on the inner circumferential surface of the outer tube, or a fin that extends in the axial direction while protruding toward the outer tube is provided on the outer circumferential surface of the inner tube. 
     
     
         4 . The nozzle structure for a hydrogen gas burner apparatus according to  claim 1 , wherein the ratio Va/Vh is substantially 1.0.