Abstract: A chemical recovery boilers is described in which the primary air system is reconfigured to provide aggressive charbed control and improved combustion in the lower furnace. The fewest number of primary air ports are used on two opposing walls to generate powerful air jets that penetrate across the boiler providing physical and thermal stability to the charbed while increasing the heat release and combustion stability in the lower furnace, increasing reduction efficiency, and lowering carryover and emissions. Various embodiments are described including operating strategies and multi-level black liquor injection.

Abstract: A ground supported power boiler is described combining a refractory lined and insulated conical floor; an insulated cylindrical combustion chamber; a cylindrical furnace with water tube wall; a rectangular convective section; a single vertical steam drum; tangential injection of the fuel and combustion air; means for fluidizing the fuel bed; means for selectively stripping particulates from the flue gases; multi-stage particulate stripping and filtering from flue gases, means for using the walls of steam drum as steam/water droplet separator, means for recirculating and capturing heat from the flue gases; means for pressurizing the interior of the boiler above atmospheric pressure; means for heating and drying fuel prior to feeding the fuel to the boiler; means for creating hydrogen shift reaction; means for eliminating any need for sootblowing; and designed to not require the use of an induced draft fan.

Abstract: A cylindrical furnace having a vertical axis controls combustion. Solid fuel, particulates, and gases inside the furnace rotate around the axis, inducing radial stratification using centrifugal forces. Fuel and particulates drag on the wall of the cylinder, slipping in and out of suspension, thereby increasing particle residence times. The solid particles comprise combustible fuel particles, and non-combustible ash and contaminants. Control of the temperature of non-combustible particles and the wall surface prevents these non-combustible particles from adhering to, and building up on, the furnace wall. It is also advantageous to control the gas temperature leaving the furnace to minimize temperature-driven corrosion of downstream heat-exchange surfaces. Method and apparatuses are described to control the gas, non-combustible particle, and wall temperatures.

Abstract: A solid fuel boiler with one or more fuel chutes configured to pre-dry wet solid fuel prior to loading into a combustion chamber of the boiler, enabling higher thermal efficiencies and burning less fuel to produce the same steam quantity. The pre-drying fuel chutes pass through the boiler where hot combustion gases radiantly and convectively—heat the chute walls to dry the wet solid fuel by radiant, convective, and/or conductive heating. Agitator mechanisms or structures within the chute mix the fuel for uniform heating, break up clumps of wet fuel, regulate the speed of falling fuel, prevent sticking, dry the fuel by means of steam and/or hot air, transport and deliver a cooling medium while a chute is offline in an operating boiler, and suppress fire using steam injection. Fuel from the chute can flow into a fuel storage bin or directly into the combustion zone of the furnace.

Abstract: A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.

Abstract: A ground supported power boiler is described combining a refractory lined and insulated conical floor; an insulated cylindrical combustion chamber; a cylindrical furnace with water tube wall; a rectangular convective section; a single vertical steam drum; tangential injection of the fuel and combustion air; means for fluidizing the fuel bed; means for selectively stripping particulates from the flue gases; multi-stage particulate stripping and filtering from flue gases, means for using the walls of steam drum as steam/water droplet separator, means for recirculating and capturing heat from the flue gases; means for pressurizing the interior of the boiler above atmospheric pressure; means for heating and drying fuel prior to feeding the fuel to the boiler; means for creating hydrogen shift reaction; means for eliminating any need for sootblowing; and designed to not require the use of an induced draft fan.

Abstract: A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.

Abstract: A ground supported power boiler is described combining a refractory lined and insulated conical floor; an insulated cylindrical combustion chamber; a cylindrical furnace with water tube wall; a rectangular convective section; a single vertical steam drum; tangential injection of the fuel and combustion air; means for fluidizing the fuel bed; means for selectively stripping particulates from the flue gases; multi-stage particulate stripping and filtering from flue gases, means for using the walls of steam drum as steam/water droplet separator, means for recirculating and capturing heat from the flue gases; means for pressurizing the interior of the boiler above atmospheric pressure; means for heating and drying fuel prior to feeding the fuel to the boiler; means for creating hydrogen shift reaction; means for eliminating any need for sootblowing; and designed to not require the use of an induced draft fan.

Abstract: A ground supported power boiler is described combining a refractory lined and insulated conical floor; an insulated cylindrical combustion chamber; a cylindrical furnace with water tube wall; a rectangular convective section; a single vertical steam drum; tangential injection of the fuel and combustion air; means for fluidizing the fuel bed; means for selectively stripping particulates from the flue gases; multi-stage particulate stripping and filtering from flue gases, means for using the walls of steam drum as steam/water droplet separator, means for recirculating and capturing heat from the flue gases; means for pressurizing the interior of the boiler above atmospheric pressure; means for heating and drying fuel prior to feeding the fuel to the boiler; means for creating hydrogen shift reaction; means for eliminating any need for sootblowing; and designed to not require the use of an induced draft fan.

Abstract: A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.

Abstract: A solid fuel boiler with one or more fuel chutes configured to pre-dry wet solid fuel prior to loading into a combustion chamber of the boiler, enabling higher thermal efficiencies and burning less fuel to produce the same steam quantity. The pre-drying fuel chutes pass through the boiler where hot combustion gases radiantly and convectively—heat the chute walls to dry the wet solid fuel by radiant, convective, and/or conductive heating. Agitator mechanisms or structures within the chute mix the fuel for uniform heating, break up clumps of wet fuel, regulate the speed of falling fuel, prevent sticking, dry the fuel by means of steam and/or hot air, transport and deliver a cooling medium while a chute is offline in an operating boiler, and suppress fire using steam injection. Fuel from the chute can flow into a fuel storage bin or directly into the combustion zone of the furnace.

Abstract: A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.

Abstract: A ground supported single drum power boiler is described combining a refractory lined and insulated stepped floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; internal chamber walls; configurable combustion air systems; a back pass with after-burner ports and cross flow superheaters; and a rear wall that acts as the downcomers feeding the other walls. A second embodiment is adaptable as a gasifier.

Abstract: A ground supported single drum power boiler is described combining a refractory lined and insulated V-Cell floor; refractory lined and insulated combustion chamber; integrated fuel chutes configured to pre-dry wet solid fuel; top mounted fuel bin; internal chamber walls; configurable combustion air systems; and a back pass with after-burner ports and cross flow superheaters. The boiler can be configured in pre-assembled modules to minimize the field construction time and cost. An alternative embodiment is adaptable as a gasifier.

Abstract: A method for drying solid fuels prior to injection and burning in solid fuel boilers is described. High moisture content solid fuels such as bark, sludge, wet coal, etc. must be dried before they can burn. Embodiments of the present invention incorporates a fuel delivery chute integrated with the boiler wall using a flow of combustion gasses and radiant heating to partially dry the solid fuel before it reaches the combustion zone of the boiler. The combustion gasses are drawn through the delivery chute by means of the flowing fuel and air jet inductors that then blows the combustion gasses back into the boiler. A refractory wall separates the fuel chute from the boiler proper, is heated by the combustion in the boiler, and radiates heat to the fuel falling through the fuel chute.

Abstract: A nozzle for the spraying of black liquor in a recovery boiler has discharge orifice inserts that can be removed and replaced with other inserts, to provide variable spray patterns, by changing the size and/or shape of the orifice of the nozzle, without requiring replacement of the entire nozzle body, to enable fine tuning of the atomization of the spray.

Abstract: A combustion air system for a recovery boiler is described in which multiple levels of secondary and tertiary combustion air ports each have an even number of ports, with the ports on opposing walls interlaced. The air system lends itself equally well to front/rear wall or sidewall applications and is especially beneficial for rectangular boilers. The air system features large and small-scale horizontal circulation zones superimposed on each other and the ability to adjust the angle of the air jets. Additional features include port dampers for the starting burners and system control based on kinetic energy.

Abstract: An indirect black liquor concentrator uses recirculating flow black liquor through a heat exchangers, employing flue gas for heat. The heated liquor is flashed, to provide steam and concentrate the liquor.

Abstract: A combustion air system for a recovery boiler is described in which multiple levels of secondary and tertiary combustion air ports each have an even number of ports, with the ports on opposing walls interlaced. The air system lends itself equally well to front/rear wall or sidewall applications and is especially beneficial for rectangular boilers. The air system features large and small-scale horizontal circulation zones superimposed on each other and the ability to adjust the angle of the air jets. Additional features include port dampers for the starting burners and system control based on kinetic energy.