Abstract: Methods of increasing the throughput of recovery boilers equipped with at least three levels of injection of air with oxygen enrichment of the air in at least one air level. In one method, a black liquor recovery boiler has three levels of air injection, and oxygen enrichment is applied to at least the secondary and the tertiary air injection levels. In another method, a black liquor recovery boiler has four levels of air injection, and oxygen enrichment is applied to one or more of the tertiary or quaternary air injection levels. In another method, a black liquor boiler has three levels of air injection, with oxygen enrichment applied to at least two air injection levels. After combustion, the oxygen concentration in the resultant flue gas is sensed. The oxygen injection is then adjusted in order to maintain the sensed oxygen concentration at the previously selected oxygen set point.

Abstract: Methods are presented to increase the throughput of a recovery boiler equipped with at least primary and secondary levels of injection of air. The methods comprise operating the recovery boiler with a third level of oxidant injection below or at the same level as the secondary level, and oxygen enrichment applied to at least the secondary level and said third level.

Abstract: Methods of increasing the throughput of recovery boilers equipped with at least two levels of injection of air are presented, the methods improving the thermal efficiency of the boiler with oxygen enrichment of the air in at least one level of the combustion air system, at or above the secondary air level. One embodiment is a method to retrofit black liquor recovery boilers having a two level air injection system with a third level of oxidant injection below or at the same level as the original secondary air, and oxygen enrichment applied to at least the original secondary air stream and said third level. A preferred method is for the third level to be placed at or close to the same level as black liquor injector ports.

Abstract: A burner assembly having improved flame length and shape control is presented, which includes in exemplary embodiments at least one fuel fluid inlet and at least one oxidant fluid inlet, means for transporting the fuel fluid from the fuel inlet to a plurality of fuel outlets, the fuel fluid leaving the fuel outlets in fuel streams that are injected into a combustion chamber, means for transporting the oxidant fluid from the oxidant inlets to at least one oxidant outlet, the oxidant fluid leaving the oxidant outlets in oxidant fluid streams that are injected into the combustion chamber, with the fuel and oxidant outlets being physically separated, and geometrically arranged in order to impart to the fuel fluid streams and the oxidant fluid streams angles and velocities that allow combustion of the fuel fluid with the oxidant in a stable, wide, and luminous flame. Alternatively, injectors may be used alone or with the refractory block to inject oxidant and fuel gases.

Abstract: Apparatus and methods suitable for recovery of heat from hot flue gases are presented comprising primary heat transfer means for exchanging heat between a hot flue gas and an intermediate fluid to create a hot intermediate fluid from an originally cold intermediate fluid; one or more oxidant-fuel burners which create the main flow of hot flue gas, and transport means for transporting the hot intermediate fluid to the heat exchanger means. The apparatus and method of the invention solve the problem of recovery of heat from dirt, toxic, or erosive flue gases.

Abstract: In accordance with the present invention, methods and apparatus to control the combustion of a burner are presented which overcome many of the problems of the prior art. One aspect of the invention comprises a burner control apparatus including a device for viewing light emitted by a flame from a burner, a device for optically transporting the viewed light into an optical processor, an optical processor for processing the optical spectrum into electrical signals, a signal processing for processing the electrical signals obtained from the optical spectrum, and a control device which accepts the electrical signals and produces an output acceptable to one or more oxidant or fuel flow control devices. The control device, which may be referred to as a “burner computer,” functions to control the oxidant flow and/or the fuel flow to the burner.

Abstract: A burner assembly having improved flame length and shape control is presented, which includes in exemplary embodiments at least one fuel fluid inlet and at least one oxidant fluid inlet, means for transporting the fuel fluid from the fuel inlet to a plurality of fuel outlets, the fuel fluid leaving the fuel outlets in fuel streams that are injected into a combustion chamber, means for transporting the oxidant fluid from the oxidant inlets to at least one oxidant outlet, the oxidant fluid leaving the oxidant outlets in oxidant fluid streams that are injected into the combustion chamber, with the fuel and oxidant outlets being physically separated, and geometrically arranged in order to impart to the fuel fluid streams and the oxidant fluid streams angles and velocities that allow combustion of the fuel fluid with the oxidant in a stable, wide, and luminous flame. Alternatively, injectors may be used alone or with the refractory block to inject oxidant and fuel gases.

Abstract: Apparatus and methods suitable for recovery of heat from hot flue gases are presented comprising primary heat transfer means for exchanging heat between a hot flue gas and an intermediate fluid to create a hot intermediate fluid from an originally cold intermediate fluid; one or more oxidant-fuel burners which create the main flow of hot flue gas, and transport means for transporting the hot intermediate fluid to the heat exchanger means. The apparatus and method of the invention solve the problem of recovery of heat from dirty, toxic, or erosive flue gases.

Abstract: A burner assembly having improved flame length and shape control is presented, which includes in exemplary embodiments at least one fuel fluid inlet and at least one oxidant fluid inlet, means for transporting the fuel fluid from the fuel inlet to a plurality of fuel outlets-, the fuel fluid leaving the fuel outlets in fuel streams that are injected into a combustion chamber, means for transporting the oxidant fluid from the oxidant inlets to at least one oxidant outlet, the oxidant fluid leaving the oxidant outlets in oxidant fluid streams that are injected into the combustion chamber, with the fuel and oxidant outlets being physically separated, and geometrically arranged in order to impart to the fuel fluid streams and the oxidant fluid streams angles and velocities that allow combustion of the fuel fluid with the oxidant in a stable, wide, and luminous flame. Alternatively, injectors may be used alone or with the refractory block to inject oxidant and fuel gases.

Abstract: In accordance with the present invention, methods and apparatus to control the combustion of a burner are presented which overcome many of the problems of the prior art. One aspect of the invention comprises a burner control apparatus including a device for viewing light emitted by a flame from a burner, a device for optically transporting the viewed light into an optical processor, an optical processor for processing the optical spectrum into electrical signals, a signal processing for processing the electrical signals obtained from the optical spectrum, and a control device which accepts the electrical signals and produces an output acceptable to one or more oxidant or fuel flow control devices. The control device, which may be referred to as a "burner computer," functions to control the oxidant flow and/or the fuel flow to the burner.

Abstract: Methods of increasing the throughput of recovery boilers equipped with at least two levels of injection of air, the methods improving the thermal efficiency of the boiler with oxygen enrichment of the air in at least one level of the combustion air system, at or above the secondary air level. In one method, a black liquor recover boiler having two levels of air injection is retrofitted with a third level of oxidant injection below or at the same level as the original secondary air, and oxygen enrichment is applied to at least the original secondary air stream and the third level air stream. A preferred method is for the third level to be placed at or close to the same level as the black liquor injector ports.

Abstract: A burner assembly having improved flame length and shape control is presented, which includes in exemplary embodiments at least one fuel fluid inlet and at least one oxidant fluid inlet, means for transporting the fuel fluid from the fuel inlet to a plurality of fuel outlets, the fuel fluid leaving the fuel outlets in fuel streams that are injected into a combustion chamber, means for transporting the oxidant fluid from the oxidant inlets to at least one oxidant outlet, the oxidant fluid leaving the oxidant outlets in oxidant fluid streams that are injected into the combustion chamber, with the fuel and oxidant outlets being physically separated, and geometrically arranged in order to impart to the fuel fluid streams and the oxidant fluid streams angles and velocities that allow combustion of the fuel fluid with the oxidant in a stable, wide, and luminous flame. Alternatively, injectors may be used alone or with the refractory block to inject oxidant and fuel gases.

Abstract: A burner assembly having improved flame length and shape control is presented, which includes in exemplary embodiments at least one fuel fluid inlet and at least one oxidant fluid inlet, means for transporting the fuel fluid from the fuel inlet to a plurality of fuel outlets, the fuel fluid leaving the fuel outlets in fuel streams that are injected into a combustion chamber, means for transporting the oxidant fluid from the oxidant inlets to at least one oxidant outlet, the oxidant fluid leaving the oxidant outlets in oxidant fluid streams that are injected into the combustion chamber, with the fuel and oxidant outlets being physically separated, and geometrically arranged in order to impart to the fuel fluid streams and the oxidant fluid streams angles and velocities that allow combustion of the fuel fluid with the oxidant in a stable, wide, and luminous flame. Alternatively, injectors may be used alone or with the refractory block to inject oxidant and fuel gases.

Abstract: In accordance with the present invention, methods and apparatus to control or monitor the combustion of a burner are presented which overcome many of the problems of the prior art. One aspect of the invention comprises a burner control apparatus comprising means for viewing light emitted by a flame from a burner, means for optically transporting the viewed light into an optical processor, optical processor means for processing the optical spectrum into electrical signals, signal processing means for processing the electrical signals obtained from the optical spectrum, and control means which accept the electrical signals and produce an output acceptable to one or more oxidant or fuel flow control means. The control means may be referred to as a "burner computer", which functions to control the oxidant flow and/or the fuel flow to the burner.