Aspirating combustion system

A method of firing a furnace with an ongoing hydrocarbon flame formed in a combustion chamber of a burner and emitted from the combustion chamber into a furnace comprising the steps of:

• circulating a cooling liquid in the burner about the combustion chamber to cool at least a portion of the burner,
• injecting a fluid hydrocarbon fuel into the combustion chamber of the burner,
• injecting a fluid hydrocarbon fuel into the combustion chamber of the burner,
• injecting an oxygen based gas into the combustion chamber,
• mixing the oxygen based gas with the fuel in the combustion chamber to form a flame in the combustion chamber,
• emitting the flame from the combustion chamber of the burner toward the furnace,
• injecting the oxygen based gas into the combustion chamber through a passage that creates a low pressure zone of oxygen based gas in the passage, the zone being in communication with the furnace, and aspirating the furnace gas from within the furnace through a passage within the liquid cooled portion of the burner with the low pressure zone of oxygen based gas and mixing the furnace gas with the oxygen based gas as the oxygen based gas and the furnace gas move toward the burner combustion chamber to reduce the temperature of the flame in the combustion chamber before the flame passes into the furnace.

A method of firing a furnace with a low temperature flame emitted from a combustion chamber of a burner, at least a portion of which is liquid cooled, comprising the steps of:

• moving a fluid hydrocarbon fuel into a combustion chamber of a burner mounted to a furnace,
• moving an oxygen based gas having an oxygen content greater than atmospheric air into the combustion chamber of the burner through a gas passage having a zone of reduced pressure with the moving oxygen based gas as the oxygen based gas moves to the combustion chamber, with the zone of low pressure being in communication with the furnace, and drawing the furnace gas with the reduced pressure zone of moving oxygen based gas from within the furnace through a passage within the liquid cooled portion of the burner and into the moving oxygen based gas and diluting the oxygen based gas with the furnace gas drawn from within the furnace,
• mixing the fuel, oxygen based gas and furnace gas in the combustion chamber and forming a low temperature flame in the combustion chamber, and
• after the flame has been formed with the mixture including the furnace gas emitting the flame from the combustion chamber of the burner toward the furnace.

A hydrocarbon fluid fuel burner for mounting to a furnace and emitting a flame into the furnace, comprising:

• a burner body for insertion partially through the wall of a furnace and projecting into the furnace,
• a combustion chamber defined in said burner body with a flame opening directed into the furnace,
• coolant circulating passage means in said burner body surrounding said combustion chamber for cooling the portion of said burner body projecting into the furnace,
• fuel conduit means for directing a flow of fuel from outside the furnace through said burner body into said combustion chamber,
• oxygen gas supply means outside the furnace for providing an oxygen based gas having an oxygen content substantially higher than 21%.
• gas conduit means for directing a flow of the oxygen based gas from said supply means outside the furnace through said burner body into said combustion chamber for mixing with the fuel and forming a flame in said combustion chamber and emitting the flame through said flame opening into the furnace,
• furnace gas conduit means in communication with the furnace extending through the liquid cooled portion of said burner body projecting into the furnace and intersecting said gas conduit means for directing a flow of furnace gas from inside the furnace into said burner for reburning by the flame formed in said combustion chamber, and
• constricted passage means in said gas conduit means at the intersection of said furnace gas conduit means with said gas conduit means for forming a low pressure zone to aspirate a flow of furnace gas through the cooled portion of said burner body into the flow of oxygen based gas moving to said combustion chamber for mixing with and diluting the oxygen based gas moving to said combustion chamber.

A method of combusting hydrocarbon fluid fuel in an ongoing hydrocarbon flame formed in a combustion chamber within a liquid cooled combustion block having an outlet nozzle directed into a hot furnace interior, to minimize the consumption of fuel and pure oxygen in the heating processes, comprising the steps of:

• circulating a cooling liquid through the combustion block about the combustion chamber,
• separately supplying hydrocarbon fluid fuel and oxygen-based oxidizing gas to the combustion chamber of the combustion block,
• directing a first fraction of the oxidizing gas supplied to the combustion chamber through at least one opening in the combustion chamber wall toward the combustion chamber,
• directing the hydrocarbon fuel supplied to the combustion chamber in a stream directed through at least one opening int the combustion chamber wall toward the first fraction of oxidizing gas so that the hydrocarbon fuel is caused to be mixed in the combustion chamber with the first fraction of oxidizing gas to stabilize combustion within the combustion chamber thereby creating a highly luminous fuel-rich hot flame core extending throughout said combustion chamber;
• directing the rest of the oxidizing gas through at least one opening in the combustion chamber wall into said combustion chamber in a stream directed about and toward the flame core so that the rest of the oxidizing gas initially insulates the flame core from cooling by contact with the liquid cooled combustion block prior to being mixed with the hydrocarbon fuel for final combustion to be conducted at least partially outside of the combustion chamber;
• discharging the products of combustion from the combustion chamber through a liquid cooled nozzle opening toward the furnace interior;
• moving furnace gas from within the furnace through at least one opening in the liquid cooled combustion block and further through the combustion chamber and into the flame and to enter the furnace with the products of combustion which are emitted from the combustion chamber of the burner, and
• controlling the flow of the hydrocarbon fuel, the oxidizing gas, and the cooling liquid toward the combustion chamber.

A method of combusting hydrocarbon fluid fuel in an ongoing hydrocarbon flame formed in a combustion chamber within a combustion block having an outlet nozzle directed into a hot furnace interior, to minimize the consumption of fuel and pure oxygen in the heating processes, comprising the steps of:

• separately supplying hydrocarbon fluid fuel and first and second oxygen-based oxidizing gases of different oxygen content to the combustion chamber of the combustion block,
• directing the first oxidizing gas supplied to the combustion chamber through at least one opening in the combustion chamber wall toward the combustion chamber,
• directing the hydrocarbon fuel supplied to the combustion chamber in a stream directed through at least one opening in the combustion chamber wall toward the first oxidizing gas so that the hydrocarbon fuel is caused to be mixed in the combustion chamber with the first oxidizing gas to stabilize combustion within the combustion chamber thereby creating a highly luminous fuel-rich hot flame core extending throughout said combustion chamber;
• directing a second oxidizing gas of lower oxygen content than the first oxidizing gas through at least one opening in the combustion chamber wall into said combustion chamber in a stream directed about and toward the flame core so that the second oxidizing gas initially insulates the flame core from being cooled by contact with the combustion block prior to being mixed with the hydrocarbon fuel for final combustion to be conducted at least partially outside of the combustion chamber;
• discharging the products of combustion from the combustion chamber through a nozzle opening toward the furnace interior;
• moving some of the furnace gas from within the furnace through at least one opening in the combustion block and further through the combustion chamber and into the flame so as to enter the furnace with the products of combustion which are emitted from the combustion chamber of the burner, and
• controlling the flow of the hydrocarbon fuel, the first oxidizing gas, and the second oxidizing gas toward the combustion chamber.