Atomizer and coal-water slurry fired boiler utilizing the same

An atomizer including a fuel supply passage for supplying a fuel, an atomizing medium supply passage for supplying an atomizing medium which is to be mixed with said fuel, a mixing chamber in communication with said fuel supply passage and said atomizing medium supply passage, and a sprayer plate constituting an outer wall of said mixing chamber and having spray ports for spraying from said mixing chamber the fluid mixture consisting of said fuel and said atomizing medium, one of said fuel supply passage and said mixing medium supply passage constituting a mixing-object fluid supply passage while the other constitutes an admixture fluid supply passage, said atomizer comprising:

• a pre-mixing chamber having an annular cross-section defined by a large-diameter cylindrical surface and a small-diameter cylindrical surface, said mixing-object fluid supply passage being connected to said mixing chamber through said pre-mixing chamber while said admixture fluid supply passage is connected to admixture fluid supply ports formed in at least one of said large-diameter cylindrical surface and said small-diameter cylindrical surface, said pre-mixing chamber having a length which is large enough to provide a fly distance sufficient for enabling said fuel supplied from said fuel supply passage and said atomizing medium supplied from said atomizing medium supply passage to be mixed in said pre-mixing chamber;
• and
• said fuel supply passage having means for spraying said fuel into said pre-mixing chamber in a film-shaped flow of an annular cross-section corresponding to said pre-mixing chamber annular cross section and in a downstream direction, and said atomizing medium supply passage having means for spraying said atomizing medium into said pre-mixing chamber downstream of said fuel spraying means in a direction crossing said downstream direction of said film-shaped flow of said fuel.

An atomizer including a fuel supply passage for supplying a fuel, an atomizing medium supply passage for supplying an atomizing medium which is to be mixed with said fuel, a mixing chamber in communication with said fuel supply passage and said atomizing medium supply passage, and a sprayer plate constituting an outer wall of said mixing chamber and having spray ports for spraying from said mixing chamber the fluid mixture consisting of said fuel and said atomizing medium, one of said fuel supply passage and said mixing medium supply passage constituting a mixing-object fluid supply passage while the other constitutes an admixture fluid supply passage, said atomizer comprising:

• a pre-mixing chamber having an annular cross-section defined by a large-diameter cylindrical surface and a small-diameter cylindrical surface, said mixing-object fluid supply passage being connected to said mixing chamber through said pre-mixing chamber while said admixture fluid supply passage is connected to admixture fluid supply ports formed in at least one of said large-diameter cylindrical surface and said small-diameter cylindrical surface, said pre-mixing chamber having a length which is large enough to provide a fly distance sufficient for enabling said fuel supplied from said fuel supply passage and said atomizing medium supplied from said atomizing medium supply passage to be mixed in said pre-mixing chamber;
• and
• another atomizing medium supply passage communicated with a swirler provided in said sprayer plate, said swirler being arranged such that the atomizing medium jetted therefrom is mixed with the mixture flow of said fuel and said atomizing medium sprayed from said mixing chamber through said spray ports.

An atomizer including a fuel supply passage for supplying a fuel, an atomizing medium supply passage for supplying an atomizing medium which is to be mixed with said fuel, a mixing chamber in communication with said fuel supply passage and said atomizing medium supply passage, and spray ports for spraying the fluid mixture consisting of said fuel and said atomizing medium, said atomizer comprising:

• a pre-mixing chamber having an annular cross-section defined by a large-diameter cylindrical surface and a small-diameter cylindrical surface, said fuel supply passage being in communication with said mixing chamber through said pre-mixing chamber, said fuel supply passage having port means for spraying said fuel into said pre-mixing chamber in a film-shaped flow of an annular cross-section corresponding to said pre-mixing chamber annular cross-section and in a downstream direction, said atomizing medium supply passage being connected to atomizing medium supply port means formed in said large-diameter cylindrical surface for spraying said atomizing medium into said pre-mixing chamber downstream of said fuel spraying means, said atomizing medium supply port means being so oriented that the flow of said atomizing medium jetted therefrom has components parallel with and perpendicular to the direction of flow of said film-shaped flow of said fuel in said pre-mixing chamber, said pre-mixing chamber having a length which is large enough to provide a fly distance sufficient for enabling said fuel supplied from said fuel supply passage and said atomizing medium supplied from said atomizing medium supply passage to be mixed in said pre-mixing chamber.

A coal-water slurry fired boiler having atomizers for atomizing a coal-water slurry by an atomizing medium, a plurality of burners provided on a wall of a furnace and adapted for mixing the atomized coal-water slurry from said atomizers with a swirl of air so as to burn said coal-water slurry, and steam heating tubes installed in said furnace so as to be heated by the gas generated by burning, wherein said atomizer comprises:

• a mixing chamber for mixing said coal-water slurry with said atomizing medium and for spraying the mixture through a plurality of spray ports;
• and
• a pre-mixing chamber having an annular cross-section and adapted for pre-mixing said coal-water slurry and said atomizing medium before they are mixed in said mixing chamber;
• and
• said pre-mixing chamber being provided with coal-water slurry passage means for spraying said coal-water slurry into said pre-mixing chamber in a film-shaped flow of an annular cross-section and in a downstream direction of movement, and atomizing medium supply passage means for supplying said atomizing medium in said pre-mixing chamber downstream of said coal-water slurry supply passage means in a direction crossing said direction of movement of said sprayed coal-water slurry having said film-shaped flow of an annular cross-section.

A coal-water slurry fired boiler having atomizers for atomizing a coal-water slurry by an atomizing medium, a plurality of burners provided on a wall of a furnace and adapted for mixing the atomized coal-water slurry from said atomizers with a swirl of air so as to burn said coal-water slurry, and steam heating tubes installed in said furnace so as to be heated by the gas generated by burning, wherein said atomizer comprises:

• a mixing chamber for mixing said coal-water slurry with said atomizing medium and for spraying the mixture through a plurality of spray ports;
• and
• a pre-mixing chamber disposed upstream of said mixing chamber, said pre-mixing chamber having an elongated cross-section perpendicular to the axis of said atomizer, the longer axis of said elongated cross-section having a length which is large enough to provide a fly distance in the direction of flow of said coal-water slurry sufficient for ensuring mixing of said coal-water slurry and said atomizing medium;
• and
• said pre-mixing chamber being provided with coal-water slurry passage means for spraying said coal-water slurry into said pre-mixing chamber in a film-shaped flow of an annular cross-section and in a downstream direction of movement, and atomizing medium supply passage means for supplying said atomizing medium in said pre-mixing chamber downstream of said coal-water slurry supply passage means in a direction crossing said direction of movement of said sprayed coal-water slurry having said film-shaped flow of an annular cross-section.

A coal-water slurry fired boiler having atomizers for atomizing a coal-water slurry by an atomizing medium, a plurality of burners provided on a wall of a furnace having a final stage and adapted for mixing the atomized coal-water slurry from said atomizers with a swirl of air so as to burn said coal-water slurry, a nose disposed in said furnace at the end of the flame of said burner so as to restrict the flow of the gas generated by the burning, and steam heating tubes installed in said furnace so as to be heated by said gas, wherein said atomizer comprises:

• a mixing chamber for mixing said coal-water slurry with said atomizing medium and for spraying the mixture through a plurality of spray ports;
• and
• a pre-mixing chamber disposed upstream of said mixing chamber having an annular cross-section determined such that the mean particle size of said coal-water slurry sprayed from said spray ports is not greater than 65 .mu.m,
• and wherein the distance between the final stage of said burners and said nose is not longer than 2.5 m per 100 MW of the rated output of said boiler.

A coal-water slurry fired boiler having atomizers for atomizing a coal-water slurry by an atomizing medium, a plurality of burners provided on a wall of a furnace and adapted for mixing the atomized coal-water slurry from said atomizers with a swirl of air so as to burn said coal-water slurry, and steam heating tubes installed in said furnace so as to be heated by the gas generated by burning.

• wherein said atomizer comprises:
• a fuel supply passage for supplying a fuel, an atomizing medium supply passage for supplying an atomizing medium which is to be mixed with said fuel, a mixing chamber in communication with said fuel supply passage and said atomizing medium supply passage, spray ports for spraying the fluid mixture consisting of said fuel and said atomizing medium, and a pre-mixing chamber having an annular cross-section, said fuel supply passage and said atomizing medium supply passage being communicated with said mixing chamber through said pre-mixing chamber, said fuel and said atomizing medium supplied from said fuel supply passage and said atomizing medium supply passage are pre-mixed in said pre-mixing chamber;
• and
• said pre-mixing chamber being provided with coal-water slurry passage means for spraying said coal-water slurry into said pre-mixing chamber in a film-shaped flow of an annular cross-section and in a downstream direction of movement, and atomizing medium supply passage means for supplying said atomizing medium in said pre-mixing chamber downstream of said coal-water slurry supply passage means in a direction crossing said direction of movement of said sprayed coal-water slurry having said film-shaped flow of an annular cross-section.

A coal-water slurry fired boiler having atomizers for atomizing a coal-water slurry by an atomizing medium, a plurality of burners provided on a wall of a furnace and adapted for mixing the atomized coal-water slurry from said atomizers with a swirl of air so as to burn said coal-water slurry, and steam heating tubes installed in said furnace so as to be heated by the gas generated by burning, said atomizer including a mixing chamber for mixing said coal-water slurry with said atomizing medium and for spraying the mixture through a plurality of spray ports, and a pre-mixing chamber having an annular cross-section and adapted for pre-mixing said coal-water slurry and said atomizing medium before they are mixed in said mixing chamber, each said burner comprising:

• a primary pre-combustion chamber coaxial with said atomizer and conically diverging from the end of said atomizer;
• a secondary pre-combustion chamber disposed ahead of said primary pre-combustion chamber;
• an annular primary air nozzle disposed on the outer periphery of said primary pre-combustion chamber and adapted for introducing into said secondary pre-combustion chamber a primary air in the form of a swirl around the axis of said atomizer;
• a secondary air nozzle disposed on the outer periphery of said secondary pre-combustion chamber and adapted for introducing into said furnace a secondary air in the form of a swirl around the axis of said atomizer;
• and
• said pre-mixing chamber being provided with coal-water slurry passage means for spraying said coal-water slurry into said pre-mixing chamber in a film-shaped flow of an annular cross-section and in a downstream direction of movement, and atomizing medium supply passage means for supplying said atomizing medium in said pre-mixing chamber downstream of said coal-water slurry supply passage means in a direction crossing said direction of movement of said sprayed coal-water slurry having said film-shaped flow of an annular cross-section.

A coal-water slurry fired boiler having atomizers for atomizing a coal-water slurry by an atomizing medium, a plurality of burners provided on a wall of a furnace and adapted for mixing the atomized coal-water slurry from said atomizers with a swirl of air so as to burn said coal-water slurry, and steam heating tubes installed in said furnace so as to be heated by the gas generated by burning, said atomizer including a fuel supply passage for supplying a fuel, an atomizing medium supply passage for supplying an atomizing medium which is to be mixed with said fuel, a mixing chamber in communication with said fuel supply passage and said atomizing medium supply passage, spray ports for spraying the fluid mixture consisting of said fuel and said atomizing medium from said mixing chamber, and a pre-mixing chamber having an annular cross-section, said fuel supply passage and said atomizing medium supply passage being communicated with said mixing chamber through said pre-mixing chamber, each said burner comprising:

• a primary pre-combustion chamber coaxial with said atomizer and conically diverging from the end of said atomizer;
• a secondary pre-combustion chamber disposed ahead of said primary pre-combustion chamber;
• an annular primary air nozzle disposed on the outer periphery of said primary pre-combustion chamber and adapted for introducing into said secondary pre-combustion chamber a primary air in the form of a swirl around the axis of said atomizer;
• a secondary air nozzle disposed on the outer periphery of said secondary pre-combustion chamber and adapted for introducing into said furnace a secondary air in the form of a swirl around the axis of said atomizer;
• and
• said pre-mixing chamber being provided with coal-water slurry passage means for spraying said coal-water slurry into said pre-mixing chamber in a film-shaped flow of an annular cross-section and in a downstream direction of movement, and atomizing medium supply passage means for supplying said atomizing medium in said pre-mixing chamber downstream of said coal-water slurry supply passage means in a direction crossing said direction of movement of said sprayed coal-water slurry having said film-shaped flow of an annular cross-section.

A coal-water slurry fired boiler having atomizers for atomizing a coal-water slurry by an atomizing medium, a plurality of burners provided on a wall of a furnace and adapted for mixing the atomized coal-water slurry from said atomizers with a swirl of air so as to burn said coal-water slurry, and steam heating tubes installed in said furnace so as to be heated by the gas generated by burning, said atomizer including a mixing chamber for mixing said coal-water slurry with said atomizing medium and for spraying the mixture through a plurality of spray ports, and a pre-mixing chamber disposed upstream of said mixing chamber, said pre-mixing chamber having an elongated cross-section perpendicular to the axis of said atomizer, the longer axis of said elongated cross-section having a length which is large enough to provide a fly distance in the direction of flow of said coal-water slurry sufficient for ensuring mixing of said coal-water slurry and said atomizing medium, each said burner comprising:

• a primary pre-combustion chamber coaxial with said atomizer and conically diverging from the end of said atomizer;
• a secondary pre-combustion chamber disposed ahead of said primary pre-combustion chamber;
• an annular primary air nozzle disposed on the outer periphery of said primary pre-combustion chamber and adapted for introducing into said secondary pre-combustion chamber a primary air in the form of a swirl around the axis of said atomizer;
• a secondary air nozzle disposed on the outer periphery of said secondary pre-combustion chamber and adapted for introducing into said furnace a secondary air in the form of a swirl around the axis of said atomizer;
• and
• said pre-mixing chamber being provided with coal-water slurry passage means for spraying said coal-water slurry into said pre-mixing chamber in a film-shaped flow of an annular cross-section and in a downstream direction of movement, and atomizing medium supply passage means for supplying said atomizing medium in said pre-mixing chamber downstream of said coal-water slurry supply passage means in a direction crossing said direction of movement of said sprayed coal-water slurry having said film-shaped flow of an annular cross-section.

An atomizer including a fuel supply passage for supplying a fuel, an atomizing medium supply passage for supplying an atomizing medium which is to be mixed with said fuel, a mixing chamber in communication with said fuel supply passage and said atomizing medium supply passage, and a sprayer plate constituting an outer wall of said mixing chamber and having spray ports for spraying from said mixing chamber the fluid mixture consisting of said fuel and said atomizing medium, one of said fuel supply passage and said mixing medium supply passage constituting a mixing-object fluid supply passage while the other constitutes an admixture fluid supply passage, said atomizer comprising:

• a pre-mixing chamber having an annular cross-section defined by a large-diameter cylindrical surface and a small-diameter cylindrical surface, said mixing-object fluid supply passage being connected to said mixing chamber through said pre-mixing chamber while said admixture fluid supply passage is connected to admixture fluid supply ports formed in at least one of said large-diameter cylindrical surface and said small-diameter cylindrical surface, said pre-mixing chamber having a length which is large enough to provide a fly distance sufficient for enabling said fuel supplied from said fuel supply passage and said atomizing medium supplied from said atomizing medium supply passage to be mixed in said pre-mixing chamber;
• another atomizing medium supply passage communicated with a swirler provided in said sprayer plate, said swirler being arranged such that the atomizing medium jetted therefrom is mixed with the mixture flow of said fuel and said atomizing medium sprayed from said mixing chamber through said spray ports;
• and
• said pre-mixing chamber being provided with coal-water slurry passage means for spraying said coal-water slurry into said pre-mixing chamber in a film-shaped flow of an annular cross-section and in a downstream direction of movement, and atomizing medium supply passage means for supplying said atomizing medium in said pre-mixing chamber downstream of said coal-water slurry supply passage means in a direction crossing said direction of movement of said sprayed coal-water slurry having said film-shaped flow of an annular cross-section.