Abstract: A heat recovery steam generator (“HRSG”) 40, which is closely coupled to a gas turbine, includes a flow controls structural array 10 disposed upstream of the tubes 42 of the HRSG 40. The structural array 10 is formed of a plurality of grate-like panels 18 secured to horizontal supports 24 mounted to the support structure of the HRSG 40. The structural array 10 diffuses the high velocity exhaust stream 14 exiting the gas turbine and redistributes the gas flow evenly throughout the HRSG 40. The structural array 10 reduces wear and damage of the tubes 46.

Abstract: In a nozzle and a nozzle assembly, for use in a pressure vessel, stress analysis is used to determine areas of stress concentration. The nozzle is configured to reduce these stress concentrations.

Abstract: An evaporator 10 for evaporating a liquid includes a plurality of harps 20 disposed within a duct or chamber such that a heated fluid flow 22 (e.g., heated gas or flue gas) passes through each successive row of harps 20 of the evaporator 10. Each of the harps 20 includes a lower header 24, a plurality of lower tubes 26, an intermediate equalizing chamber 28, a plurality of upper tubes 30, and an upper header 32. The lower tubes 30 are in fluid communication with the lower header 24 and extend upward vertically from the lower header. The upper ends of the lower tubes 26 are in fluid communication with the equalizing chamber 28. The upper tubes 30 are in fluid communication with the equalizing chamber 28 and extend upward vertically from the equalizing chamber. The upper ends of the upper tubes 30 are in fluid communication with the upper header 32.

Abstract: A heat recovery steam generator that includes a first steam drum for receiving a flow of water and steam from an evaporator. The first steam drum is adapted to provide the flow of water and steam to a second steam drum. The second steam drum is in fluid communication with the first steam drum and receives the flow of water and steam from the first steam drum and separates steam from the flow of water and steam to form a separated steam. There is a steam flow outlet positioned in the second steam drum, the steam flow outlet adapted to release the separated steam from the second steam drum.

Abstract: A radial nozzle assembly for use in a pressure vessel to enable fluid flow through the vessel wall is provided. The radial nozzle assembly has a nozzle and a cup-shaped flange extending from one end of the nozzle. The nozzle has a bore disposed therethrough along its length to permit fluid flow through the wall of the pressure vessel. The flange is defined by a generally cup or dome-shaped wall having an open end. The nozzle assembly is secured to the wall of the vessel such that the nozzle is disposed in a radial orientation to the flange and possibly in a horizontal orientation.

Abstract: An evaporator for steam generation is presented. The evaporator includes a plurality of primary evaporator stages and a secondary evaporator stage. Each primary stage includes one or more primary arrays of heat transfer tubes, an outlet manifold coupled to the arrays, and a downcomer coupled to the manifold. Each of the primary arrays has an inlet for receiving a fluid and is arranged transverse to a flow of gas through the evaporator. The gas heats the fluid flowing through the arrays to form a two phase flow. The outlet manifold receives the two phase flow from the arrays and the downcomer distributes the flow as a component of a primary stage flow. One or more of the plurality of primary evaporator stages selectively form the primary stage flow from respective components of the two phase flow, and provide the primary stage flow to inlets of the secondary evaporator stage.

Abstract: A radial nozzle assembly for use in a pressure vessel to enable fluid flow through the vessel wall is provided. The radial nozzle assembly has a nozzle and a cup-shaped flange extending from one end of the nozzle. The nozzle has a bore disposed therethrough along its length to permit fluid flow through the wall of the pressure vessel. The flange is defined by a generally cup or dome-shaped wall having an open end. The nozzle assembly is secured to the wall of the vessel such that the nozzle is disposed in a radial orientation to the flange and possibly in a horizontal orientation.

Abstract: In a nozzle and a nozzle assembly, for use in a pressure vessel, stress analysis is used to determine areas of stress concentration. The nozzle is configured to reduce these stress concentrations.

Abstract: An evaporator system comprises an evaporator; a drum; and a pump that are in fluid communication with each other. The pump is operative to create a temporary pressure gradient during start-up of an evaporator system and transport a fluid from the evaporator to the drum prior to the fluid reaching its boiling point in the evaporator. Following the fluid reaching its boiling point in the evaporator, the fluid naturally circulates in the evaporator system.

Abstract: A heat recovery steam generator that includes a first steam drum for receiving a flow of water and steam from an evaporator. The first steam drum is adapted to provide the flow of water and steam to a second steam drum. The second steam drum is in fluid communication with the first steam drum and receives the flow of water and steam from the first steam drum and separates steam from the flow of water and steam to form a separated steam. There is a steam flow outlet positioned in the second steam drum, the steam flow outlet adapted to release the separated steam from the second steam drum.

Abstract: An evaporator for steam generation is presented. The evaporator includes a plurality of primary evaporator stages and a secondary evaporator stage. Each primary stage includes one or more primary arrays of heat transfer tubes, an outlet manifold coupled to the arrays, and a downcomer coupled to the manifold. Each of the primary arrays has an inlet for receiving a fluid and is arranged transverse to a flow of gas through the evaporator. The gas heats the fluid flowing through the arrays to form a two phase flow. The outlet manifold receives the two phase flow from the arrays and the downcomer distributes the flow as a component of a primary stage flow. One or more of the plurality of primary evaporator stages selectively form the primary stage flow from respective components of the two phase flow, and provide the primary stage flow to inlets of the secondary evaporator stage.

Abstract: A method of controlling stress in a boiler pressure vessel comprises limiting the diameter of a drum (10) of the boiler pressure vessel and preheating at least a portion of the wall (12) of the drum (10). Limiting the diameter of the drum (10) allows pressure in the drum (10) to be increased for a given mechanical stress. Furthermore, preheating the wall (12) of the drum (10) reduces peak thermally induced stresses in a material from which the drum (10) is fabricated.

Abstract: A heat recovery steam generator (“HRSG”) 40, which is closely coupled to a gas turbine, includes a flow controls structural array 10 disposed upstream of the tubes 42 of the HRSG 40. The structural array 10 is formed of a plurality of grate-like panels 18 secured to horizontal supports 24 mounted to the support structure of the HRSG 40. The structural array 10 diffuses the high velocity exhaust stream 14 exiting the gas turbine and redistributes the gas flow evenly throughout the HRSG 40. The structural array 10 reduces wear and damage of the tubes 46.

Abstract: An evaporator 10 for evaporating a liquid includes a plurality of harps 20 disposed within a duct or chamber such that a heated fluid flow 22 (e.g., heated gas or flue gas) passes through each successive row of harps 20 of the evaporator 10. Each of the harps 20 includes a lower header 24, a plurality of lower tubes 26, an intermediate equalizing chamber 28, a plurality of upper tubes 30, and an upper header 32. The lower tubes 30 are in fluid communication with the lower header 24 and extend upward vertically from the lower header. The upper ends of the lower tubes 26 are in fluid communication with the equalizing chamber 28. The upper tubes 30 are in fluid communication with the equalizing chamber 28 and extend upward vertically from the equalizing chamber. The upper ends of the upper tubes 30 are in fluid communication with the upper header 32.

Abstract: A splitter plate arrangement is provided for controlling the flow of flue gas in a vertical stack. The splitter plate arrangement 100 is operable to control the flow of flue gas in a vertical stack 128 having an annular entry 130 communicated with two inlets 126A, 126B which each communicate a respective one of the flue gas producers with the vertical stack 128. The inlets 126A, 126B are both disposed on a common inlet axis which bisects the annular entry 130 into two bisected halves, the two inlets 126A, 126B are oriented in opposition to one another such that the inlet flow 132 of flue gas through the inlet 126A flows in a direction opposite to the inlet flow 134 of flue gas through the inlet 126B. The splitter plate arrangement 100 includes a first splitter plate 136 and a second splitter plate 138.

Abstract: An air compartment of a corner windbox of a tangential firing system of a fossil fuel-fired furnace for injecting secondary air into the furnace. The air compartment includes a channel portion with an entrance end communicating with an air delivery duct and an exit end communicating via an exit assembly with the furnace opening. The exit assembly includes at least one vane for guiding an air stream and a mounting frame for supporting the vane relative to the channel portion for guiding thereby of an air stream passing from the channel portion through the furnace opening into the furnace. The vane includes a surface portion which intersects the horizontal plane at an acute angle and a pair of opposed transverse edges. The vane and the mounting frame are disposed within the channel portion such that the leading edge of the vane is upstream of the furnace opening.

Abstract: Sulfur oxides (SO.sub.x) are scrubbed from combustion effluents with greater system reliability when an improved mist eliminator of the invention is employed. The mist eliminator has at least one section, preferably two sections, with two passes followed by an extended trailing edge. This design is shown in tests to be as effective as four pass designs, while being easier to clean. Encrustation and plugging are greatly reduced.

Abstract: A duct for joining a higher velocity application to a lower velocity application such as a heat recovery vapor generator inlet duct apparatus for installation intermediate the exhaust of an associated gas turbine and an associated heat recovery vapor generation apparatus which includes a housing having an inlet and an outlet. The housing has the inlet and the outlet axially offset with respect to each other; and apparatus for directing fluid flow from the inlet to the outlet, the apparatus for directing fluid flow including at least one array of mutually parallel flat plates in stair step relationship extending substantially across the path of gases entering the inlet. In some forms of the invention the apparatus also includes a second array of mutually parallel flat plates in stair step relationship extending substantially across the path of gases exiting through the outlet.

Abstract: A furnace (10) for burning cellulosic fuel has walls (64) which taper upwardly and outwardly, such that a given level or height (66) the cross-sectional flow area is 11/2 to 2 times the cross-sectional flow area near the bottom of the furnace. Thus the gas velocity continuously decreases, as the cross-sectional area increases. Any partially burned char particles initially entrained in the gases near the furnace bottom reach a height in the furnace where the gas velocity equals the particle terminal velocity, so that the particles remains suspended at this height until combustion as reduced their size enough so they can be carried on out of the furnace by the reduced gas velocity.

Abstract: A sonic atomizing spray nozzle (40) wherein a slurry (30) of finely-divided sulfur oxide absorbent particles in a carrier liquid is sprayed into a flue gas stream (12) entering a drying chamber (20) through a continuous circumferential slit (70) as a radially outwardly directed thin continuous sheet (28). The thickness of the sheet can be varied to optimize atomization over a range of slurry flow rates by varying the width of slit (70).