Combustion Engineering, Inc.

Alstom Technology Limited

Other

Alstom (switzerland) Ltd

Abb Environmental Systems, Division of Abb Flakt, Inc.

David K Anderson

Michael J Rini

Frederic Zenon Kozak

Martin J Kozlak

Arlyn V Petig

Mou Jian

Robert G Hilton

Noel C Kuck

Keri N Cochran

James A Yann

Tom C Lillestolen

Marie L Aumaugher

Thomas S Raines

Wesley Paul Bauver, Ii

Srivats Srinivasachar

Wayne S Counterman

James David Seebald

Mark Palkes

Majed A Toqan

Todd D Hellewell

Richard C LaFlesh

John H Chiu

Michael G Varner

David Gordon Turek

David P Towle

Joseph David Bianca

Mark R Malo

Greg N Liljedahl

Donald G Mylchreest

Patrick L Jennings

Robert W Koucky

John L Marion

Kjell E Porle

Friedrich W Pinnekamp

William H Kingston

Steven F McNary

Nicole M Phyfe

One embodiment described herein relates to a system for removing pollutants from a flue gas. The system includes a selective catalytic reduction (SCR) system having a SCR reactor containing a NOreducing catalyst and one or more SCR protective devices. At least one of the SCR protective devices is connected to a rapping hammer system that actively remove fly ash collected on the SCR protective devices.

Device and method for cleaning selective catalytic reduction protective devices

A method for removing pollutants from flue gas generated by a plant having one or more burners located at an inlet end of a vertically extending stack, the flue gas being discharged through an outlet end of the stack. The pollutants are removed by an emission treatment system which includes a major component module and inlet and outlet ductwork providing fluid communications between the stack and the major component module. The major component module includes an SCR segment, a heat exchanger segment, and an ID fan, the SCR segment having at least one catalyst unit composed of materials for selectively catalyzing at least one pollutant. The method comprises the steps of drawing the flue gas from the stack and through the major component module with the ID fan, removing the pollutant from the flue gas with the SCR segment to produce a clean flue gas, and discharging the clean flue gas to the stack with the ID fan.

Method for treating emissions

An emission treatment system for removing NOfrom flue gas includes a diversion member that closes the stack at a position intermediate the inlet and outlet ends. A major component module includes a first sub-module, having an inlet and an SCR segment, a second sub-module, having a heat exchange segment, and a third sub-module, having an ID fan and an outlet, forming a flue gas flow path extending from the inlet to the outlet. Inlet ductwork, which is in fluid communication with the stack at a position intermediate the inlet end of the stack and the diversion member, provides a passageway from the stack to the inlet. Outlet ductwork, which is in fluid communication with the stack at a position intermediate the diversion member and the outlet end of the stack, provides a passageway from the outlet to the stack. An ammonia addition subsystem injects ammonia vapor into the inlet ductwork.

Emission treatment system

A circulating fluidized bed steam generator and a method for operating the circulating fluidized bed steam generator are provided which offer the flexibility to use carbon dioxide (CO ) both as a desirable end product and as support to the combustion process. The method includes the step of introducing a substantially pure oxygen feed stream into the circulating fluidized bed steam generator and the step of combusting a fuel in the presence of the substantially pure oxygen feed stream to produce a flue gas having carbon dioxide and water vapor as its two largest constituent elements by volume. The method also includes the step of passing the flue gas through an oxygen feed stream pre-heater at which heat from the flue gas is transferred to the oxygen feed stream. Furthermore, the method includes the step of separating the flue gas into an end product portion and a recycling portion. The method additionally includes cooling and compressing the end product portion of the flue gas so as to yield carbon dioxide in a liquid phase and directing the recycling portion of the flue gas to the circulating fluidized bed steam generator to contribute to the combustion process therein.

Oxygen fired circulating fluidized bed steam generator

The flue gas temperature coming from an air preheater to a particulate collection device such as an electrostatic precipitation or fabric filter is reduced to improve the operation of the particulate collection device. This may be done by reducing the exit flue gas temperature from the air preheater or reducing the temperature after exiting. In one embodiment, air in excess of that needed for combustion is passed through the air preheater with the heated excess air either being dumped or used for a variety of purposes in the plant. A particular embodiment involves segmenting the air outlet side of a rotary regenerative air preheater and withdrawing the excess air from the segment where the dust loading is the lowest. Further, additional cooling of the flue gas can be provided by reducing the quantity of primary air that typically bypasses the air preheater and then providing other ways to control the primary air temperature to the pulverizers. The flue gas temperature may also be cooled after the air preheater by heat exchange or spray cooling with water.

Steam generator system operation

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.

Mist eliminator for wet gas scrubbing

There is provided a circulating fluidized bed steam generator (CFB) having an improved structural support system and an improved combined hot solids-gas separator for separating gas and solids from a combined gas-solids stream. The combined hot solids-gas separator is in the form of a cyclone assembly having a plurality of wall portions forming a separation chamber and an inlet for passage of a combined gas-solids stream into the separation chamber. The lowermost extent of the inlet forms a threshold over which the combined gas-solids stream flows in entering the separation chamber. The separation chamber is operable to separate the combined gas-solids stream into a predominantly gas exit stream and a predominantly solids exit stream in a manner by which separated out solids to be discharged from the separation chamber via the predominantly solids exit stream are collected within the separation chamber at a location lower than the inlet. The cyclone assembly further includes a separated solids discharge for the discharge therethrough of the predominantly solids exit stream having the collected separated out solids therein and a gas outlet duct for outward flow of the predominantly gas exit stream out of the separation chamber.

Steam generator having an improved structural support system

A system and method of injecting an ammonia or urea reactant into a flue gas stream in a steam generating power plant that utilizes Selective Catalytic Reduction (SCR) to lower NO.sub.x emissions and more specifically the injection of the reactant in such a manner that a more uniform mixing of the reactant with the flue gas stream is achieved more rapidly thereby increasing the efficiency of the catalytic reduction process and further a method of increasing the amount of reaction that takes place between the reactant/flue gas mixture and the catalytic material.

SCR reactant injection grid

A combined cycle system has a gas turbine connected to a heat recovery steam generator and the heat recovery steam generator contains a selective catalytic reactor section wherein nitrogen oxides (NO.sub.x) are reacted with reactant gas such as ammonia or urea to produce molecular nitrogen and water vapor. The expanding transition section contains an array of flow profile control pipes extending across the section in a pattern which distribute the flue gas uniformly over the large cross-section of the heat transfer section. The reactant gas is injected into the flue gas stream through a series of nozzles spaced across the flow control pipes so as to uniformly mix and distribute the reactant gas in the flue gas stream before it enters the selective catalytic reactor section.

Method and apparatus for injecting reactant for catalytic reduction in a

An integrated low NO.sub.x tangential firing system (12) that is particularly suited for use with pulverized solid fuel-fired furnaces (10), and a method of operating a pulverized solid fuel-fired furnace (10) equipped with an integrated low NO.sub.x tangential firing system (12). The integrated low NO.sub.x tangential firing system (12) when so employed with a pulverized solid fuel-fired furnace (10) is capable of limiting NO.sub.x emissions therefrom to less than 0.15 lb./10.sup. 6 BTU, while yet maintaining carbon-in-flyash to less than 5% and CO emissions to less than 50 ppm. The integrated low NO.sub.x tangential firing system (12) includes pulverized solid fuel supply means (62), flame attachment pulverized solid fuel nozzle tips (60), concentric firing nozzles, close-coupled overfire air (98,100), and multi-staged separate overfire air (104,106).

Integrated low NO.sub.x tangential firing system

A nozzle damper assembly (10) for installation in a duct (12) operative for measuring and controlling the flow of a gaseous medium through the duct (12). The subject nozzle damper assembly (10) includes enclosure means (24) cooperatively associated with the duct (12), shaft means (26) suitably supported from the sidewalls (32, 34, 36, 38) of the enclosure means (24), damper blade means (16,18) rotatable mounted on the shaft means (26) for movement within the enclosure means (24), damper blade operating means (28) operative for purposes of effecting the movement of the damper blade means (16,18) within the enclosure means (24), and flow measurement means (20,22) supported at a first location and at a second location relative to in lieu thereof the damper blade means (16,18) and operative to measure the flow of the gaseous medium through the nozzle damper assembly (10) such that control may be exercised over the flow of the gaseous medium through the duct (12) based on such measurements.

Nozzle damper assembly

In a furnace (10) in which a sulfur-bearing fuel is burned, a sorbent material such as limestone is introduced into the upper portion of the furnace through a plurality of nozzle arrangements (40). Each nozzle arrangement comprises a pair of concentric pipes (42,44) with deflector means (46) located between the pipes and adjustable by means (54), so that the sorbent material introduced through the outer pipe is dispersed in an area near the furnace wall, while that introduced through the inner pipe is projected to the central portion of the furnace. There are sufficient nozzle arrangements, and they are so located, so as to cover substantially the entire cross-sectional area of the furnace with sorbent material.

Sorbent injection system

A furnace (10) in which pulverized coal is burned in suspension. The coal is introduced along with primary air, tangent to an imaginary circle (42). The auxiliary air is introduced tangent to an imaginary circle (44) directly above the primary air, in a direction of rotation opposite that of the primary air. The auxiliary air is directed tangent to a circle of greater diameter than that of the primary air. There are a plurality of alternating levels within the furnace where primary air (38), and then auxiliary air (40), is introduced.

Low excess air tangential firing system

A furnace (10) having burner means (12) associated with it for burning a sulfur-bearing fuel. Sorbent material, such as limestone, is introduced through nozzles (34) along a pipe (32) extending across the width of the furnace above the nose (31) in the upper portion of the furnace, so that the pipe and the sorbent are protected from heat radiation from the combustion within the furnace.

A furnace (10) in which bark or other cellulosic fuel (64) is burned on a traveling grate (24). Char (62) separated (48, 54) from the furnace exhaust gases is reinjected into the furnace beneath baffle plate (40) in such a manner that the raw bark (64) being introduced onto the grate forms a protective cover over the char (62) thus preventing the relatively light char particles from becoming reentrained in the gases before they are completely combusted.

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East Longmeadow, MA, United States of America

David K Anderson