The Babcock & Wilcox Company

Babcock & Wilcox Power Generation Group, Inc.

Foster Wheeler Energia Oy

Donald L Wietzke

Mikhail Maryamchik

David J Walker

Michael J Szmania

Felix Belin

Kiplin C Alexander

David E James

Gary L Anderson

Neil R Raskin

Scott Darling

Michael L Silvey

Sundara M Kavidass

David R Gibbs

Stephen W Borsani

Richard F Romansky, Jr

William C Henson

Joseph C Comanitz

A system can quickly cool and de-pressurize a boiler arrangement under non-normal operating conditions such as loss of plant power. A discharge system injects into the furnace a combined stream of steam from a steam discharge system and ambient air, thereby both cooling components of the boiler arrangement and reducing pressure in the steam/water circuit. This reduces or eliminates the additional cost associated with providing extra capacity in a steam drum and/or an independently powered boiler water pump. The system is particularly useful for quickly cooling the U-beams of a circulating fluidized bed boiler during a black plant condition.

Furnace cooling by steam and air injection

A bubble cap assembly for an air distribution grid includes a stem having a top region and a bottom region, a bubble cap connected to the top region of the stem, a membrane having an opening, the bottom region of the stem communicating with the opening; a flange connected to the bottom region of the stem; at least one clamp for pressing the flange against the membrane, and a gasket squeezed between the flange and the membrane by the clamp to provide an air-tight connection between the flange and the membrane.

Fluidizing nozzle or bubble cap assembly for air distribution grid

A system and method for quickly cooling and de-pressurizing a boiler arrangement in the event of a plant power loss, a.k.a. a black plant condition. A steam discharge system injects steam from the steam/water circuit into the furnace, thereby both cooling components of the boiler arrangement and reducing pressure in the steam/water circuit. This reduces or eliminates the additional cost associated with providing extra capacity in a steam drum and/or an independently powered boiler water pump. The system and method is particularly useful for quickly cooling the U-beams of a circulating fluidized bed (CFB) boiler during a black plant condition. In application to boiler arrangements with a selective non-catalytic reduction (SNCR) system employing steam as a carrier for a NOreducing agent, the steam discharge system advantageously uses the discharge nozzles of the SNCR system to inject the steam into the furnace.

Black plant steam furnace injection

An integrated fluidized bed ash cooler for a fluidized bed boiler, particularly a circulating fluidized bed (CFB) boiler, employs at least two fluidized bed sections positioned in series along a solids flow path. Each section contains fluidizing means, the first section along the solids path being separated from a following section with a threshold. The first section contains means for measuring a bed temperature in the vicinity of the fluidizing means and at a higher elevation within the fluidized bed. Means are provided for removing oversized bed material from the first section to facilitate the removal of ash while minimizing the possibility of ash plugging during operation.

Integrated fluidized bed ash cooler

A CFB reactor or combustor having a selective catalytic reduction (SCR) system () employed downstream of the CFB reactor or combustor furnace () together with a dry scrubber system () to achieve enhanced NOreduction.

Circulating fluidized bed reactor with selective catalytic reduction

A circulating fluidized bed (CFB) unit utilizing a mechanical dust collector located in a vertical flue above at least one heat exchange surface, and at least partially underneath the floor of a non-vertical flue, includes a plurality of individual collection elements each having a downward bottom outlet for a flow of cleaned gas conveyed through the collection elements.

Compact footprint CFB with mechanical dust collector

A fluidized bed reactor includes at least one furnace section delimited by side walls and a bottom grid, the at least one furnace section provided for containing a bed of fluidized solid particles therein, and a supply for introducing a gas into the at least one furnace section at a level above the bottom grid. The supply includes (i) a gas source chamber, (ii) at least one opening in at least one of the side walls at a level above the bottom grid, and (iii) at least one conduit, having a first end connected to the at least one opening at a first vertical level and a second end connected to the gas source chamber for introducing gas from the gas source chamber to the at least one furnace section. The at least one conduit provides a solid flow preventing element for preventing solid particles from flowing backward from the at least one furnace section into the at least one conduit.

Fluidized bed reactor

A collection element arrangement is provided having sleeve attachments near their lowermost ends which simulate a continuous sloping surface, or floor. The sleeve attachments upper surfaces forming the floor permit collected solids to flow down the sloping surface back into the furnace or reactor chamber. Stainless steel can be used for the collection elements and sleeve attachments since the floating floor accommodates differential thermal expansion between CFB components.

Floored impact-type solids separator using downward expanding separator elements

A circulating fluidized bed (CFB) boiler has one or more bubbling fluidized bed enclosures containing heating surfaces and located within a lower portion of the CFB boiler to provide a compact, efficient design with a reduced footprint area. The heating surfaces are provided within the bubbling fluidized bed located above a CFB grid and/or in a moving packed bed below the CFB grid inside the lower portion of the CFB boiler. Solids in the bubbling fluidized bed are maintained in a slow bubbling fluidized bed state by separately controlled fluidization gas supplies. Separately controlled fluidization gas is used to control bed level in the bubbling fluidized beds or to control the throughput of solids through the bubbling fluidized beds. Solids ejected from the bubbling fluidized beds can be returned directly into the surrounding CFB environment of the CFB boiler, or purged from the system for disposal or recycle back into the CFB. Solids which are recycled back to the CFB have less heat and can be used to control the temperature of the fast moving bed in the CFB.

CFB with controllable in-bed heat exchanger

Apparatus for separating solids from flue gas in a circulating fluidized bed (CFB) boiler includes plural vertical, impact type particle separators made of cooling tubes located within the CFB in a plurality of staggered rows. One embodiment employs a plurality of stacked, slip fit elements having apertures which accept the cooling tubes. The slip fit elements cooperate with one another to form a collecting channel, typically U-shaped, which separates particles from flue gases conveyed across the particle separators. Shiplap joints in between the individual slip fit elements prevent gas and solids from leaking therebetween and allow for thermal expansion. Alternatively, the impact type particle separators include cooling tubes connected to one another to form a unitary structure. Pin studs welded to the cooling tubes and covered with a coating of refractory; ceramic tiles; metal or ceramic spray coatings; metal or ceramic castings; weld overlay; and/or shields provide erosion resistance.

Cooled tubes arranged to form impact type particle separators

A tube wall, division wall, or wing wall section ( ) for a circulating fluidized bed boiler with improved erosion resistant characteristics has a reduced diameter tube section ( ) adjacent the refractory covered by an abrasion resistant refractory tile ( ). The refractory tile ( ) is mounted to the reduced diameter tube section ( ) with the upper edge of the refractory tile outside of or not extending beyond a solids fall line of solids in the fluidized bed to eliminate exposed discontinuities.

Wall protection from downward flowing solids

Apparatus for separating solids from flue gas in a circulating fluidized bed (CFB) boiler comprises plural vertical, impact type particle separators located within the CFB in a plurality of staggered rows. The impact type particle separators employ hung elements supported from fluid-cooled tubes which form a collecting channel, typically U-shaped, which separates particles from flue gases conveyed across the particle separators. By separating the support function from the collection shape required by functional performance considerations, the strength requirements of the material used to form the collection shape are reduced and the strength of the material from which the fluid-cooled support is made is much higher due to the lower operating temperature of the material comprising the fluid-cooled support, thereby permitting the use of lower cost materials.

CFB impact type particle collection elements attached to cooled supports

A CFB reactor or combustor having a selective catalytic reduction (SCR) system employed downstream of the CFB reactor or combustor furnace together with a dry scrubber system to achieve enhanced NO, reduction.

A CFB furnace or reactor unit is provided having enhanced circulation of the reagents finest particles. The improved circulation is achieved by recycling gas having entrained fine particles from a solids collection hopper connected to the solids separator back into the reactor. A system of one or more conduits connects the upper portion of the solids collection hopper with the reactor. The conduit system is equipped with means for recycling gas from the hopper to the reactor. The invention is an inexpensive system which permits recycling of the finest particles that would otherwise be carried over with the gas flow exiting the separator.

Fine solids recycle in a circulating fluidized bed

A tube wall, division wall, or wing wall section for a circulating fluidized bed boiler with improved erosion resistant characteristics has a reduced diameter tube section adjacent the refractory covered by an abrasion resistant refractory tile. The refractory tile is mounted to the reduced diameter tube section with the upper edge of the refractory tile outside of or not extending beyond a solids fall line of solids in the fluidized bed to eliminate exposed discontinuities.

Growing community of inventors

Carlsbad, CA, United States of America

Donald L Wietzke