Abstract: A spray dryer absorber (SDA) system used to reduce the concentration of at least one acid compound in a gas utilizes low or no alkali-containing particulate compounds to prevent cementing during operation. The low or no-alkali-containing compounds may be supplied from external sources and/or from a particulate collection device located downstream of the SDA.

Abstract: 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.

Abstract: A concentrated solar power (CSP) system includes channels arranged to convey a flowing solids medium descending under gravity. The channels form a light-absorbing surface configured to absorb solar flux from a heliostat field. The channels may be independently supported, for example by suspension, and gaps between the channels are sized to accommodate thermal expansion. The light absorbing surface may be sloped so that the inside surfaces of the channels proximate to the light absorbing surface define downward-slanting channel floors, and the flowing solids medium flows along these floors. Baffles may be disposed inside the channels and oriented across the direction of descent of the flowing solids medium. The channels may include wedge-shaped walls forming the light-absorbing surface and defining multiple-reflection light paths for solar flux from the heliostat field incident on the light-absorbing surface.

Abstract: 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 an in-bed heat exchanger (IBHX). Solids in the bubbling fluidized bed are maintained in a slow bubbling fluidized bed state by separately controlled fluidization gas supplies. The beds feature open bottom distribution grids with hoppers disposed below to collect solids. The enclosure defining the IBHX is supported from structures below the grids and the enclosure can be supported from the hoppers.

Abstract: A solar power system comprises a solar receiver, a heated solids storage tank downstream of the solar receiver, a fluidized bed heat exchanger downstream of the heated solids storage tank, and means for transporting solid particles from the fluidized bed heat exchanger to a cold solids storage tank upstream of the solar receiver. The fluidized bed heat exchanger includes a first fluidized bed and a second fluidized bed. Solid particles flow through the fluidized bed heat exchanger and transfer heat energy to heating surfaces in the two fluidized beds. The system permits the solid particles to absorb more energy and permits a constant energy output from the fluidized bed heat exchanger.

Abstract: 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.

Abstract: A dual phase fuel feeder is disclosed that can be used to provide both solid fuels and liquid fuels to a boiler, such as a fluidized bed boiler. The fuel feeder includes a sloped chute which defines a solid feedpath. Gas distribution nozzles are located at the base of the fuel feeder, and secondary nozzles are located so as to be able to distribute a liquid or particulate fuel into the solid feedpath. This permits the liquid fuel to contact the solid fuel and be carried into the fluidized bed instead of becoming suspended above the bed.

Abstract: A power plant includes a solar receiver heating solid particles, a standpipe receiving solid particles from the solar receiver, a pressurized heat exchanger heating working fluid by heat transfer through direct contact with heated solid particles flowing out of the bottom of the standpipe, and a flow path for solid particles from the bottom of the standpipe into the pressurized heat exchanger that is sealed by a pressure P produced at the bottom of the standpipe by a column of heated solid particles of height H. The flow path may include a silo or surge tank comprising a pressure vessel connected to the bottom of the standpipe, and a non-mechanical valve. The power plant may further include a turbine driven by heated working fluid discharged from the pressurized heat exchanger, and a compressor driven by the turbine.

Abstract: 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.

Abstract: A concentrated solar power (CSP) system includes channels arranged to convey a flowing solids medium descending under gravity. The channels form a light-absorbing surface configured to absorb solar flux from a heliostat field. The channels may be independently supported, for example by suspension, and gaps between the channels are sized to accommodate thermal expansion. The light absorbing surface may be sloped so that the inside surfaces of the channels proximate to the light absorbing surface define downward-slanting channel floors, and the flowing solids medium flows along these floors. Baffles may be disposed inside the channels and oriented across the direction of descent of the flowing solids medium. The channels may include wedge-shaped walls forming the light-absorbing surface and defining multiple-reflection light paths for solar flux from the heliostat field incident on the light-absorbing surface.

Abstract: A power plant includes a solar receiver heating solid particles, a standpipe receiving solid particles from the solar receiver, a pressurized heat exchanger heating working fluid by heat transfer through direct contact with heated solid particles flowing out of the bottom of the standpipe, and a flow path for solid particles from the bottom of the standpipe into the pressurized heat exchanger that is sealed by a pressure P produced at the bottom of the standpipe by a column of heated solid particles of height H. The flow path may include a silo or surge tank comprising a pressure vessel connected to the bottom of the standpipe, and a non-mechanical valve. The power plant may further include a turbine driven by heated working fluid discharged from the pressurized heat exchanger, and a compressor driven by the turbine.

Abstract: Alkali-containing bottom ash produced by a circulating fluidized bed (CFB) boiler is recycled to downstream spray dryer absorption (SDA) apparatus to more fully utilize the unused reagent present in the ash, and/or to reduce the amount of reagent used while not increasing NOx generation.

Abstract: 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.

Abstract: A solar power system comprises a solar receiver, a heated solids storage tank downstream of the solar receiver, a fluidized bed heat exchanger downstream of the heated solids storage tank, and means for transporting solid particles from the fluidized bed heat exchanger to a cold solids storage tank upstream of the solar receiver. The fluidized bed heat exchanger includes a first fluidized bed and a second fluidized bed. Solid particles flow through the fluidized bed heat exchanger and transfer heat energy to heating surfaces in the two fluidized beds. The system permits the solid particles to absorb more energy and permits a constant energy output from the fluidized bed heat exchanger.

Abstract: A dual phase fuel feeder is disclosed that can be used to provide both solid fuels and liquid fuels to a boiler, such as a fluidized bed boiler. The fuel feeder includes a sloped chute which defines a solid feedpath. Gas distribution nozzles are located at the base of the fuel feeder, and secondary nozzles are located so as to be able to distribute a liquid or particulate fuel into the solid feedpath. This permits the liquid fuel to contact the solid fuel and be carried into the fluidized bed instead of becoming suspended above the bed.

Abstract: A non-mechanical valve arrangement for use with circulating fluidized bed (CFB) boilers has a CFB reaction chamber and a bubbling fluidized bed (BFB) within an enclosure in the lower portion of the CFB reaction chamber, the BFB containing an in-bed heat exchanger (IBHX). Solids flowing from the BFB enclosure to the CFB reaction chamber may be controlled using one or more non-mechanical valves. Each non-mechanical valve is independently controlled using independently controlled fluidizing means. The non-mechanical valve has collectors to collect solids backsifting into the fluidizing means of the valve. Agglomerates are removed which could block the valve. Channel walls parallel to the direction of solids flow through the valve opening may be provided to reduce external interference with local fluidization to maintain the proper functionality of the non-mechanical valve.

Abstract: A circulating fluidized bed (CFB) boiler includes a reaction chamber, where a bubbling fluidized bed (BFB) is contained within an enclosure within the lower portion of the reaction chamber and contains an in-bed heat exchanger (IBHX) that occupies part of the reaction chamber floor. A plurality of in-bed secondary air nozzles comprise a plurality of tubes which are grouped together and run across the width of the BFB between the BFB enclosure wall and an outside wall of the CFB. The nozzles are positioned to prevent the deflection of solids falling onto the BFB from the CFB by the secondary air jets while avoiding a complicated structure that would interfere with gas and/or solids movement in the furnace. The nozzles' exit openings are flush, or almost flush, with the BFB enclosure wall.

Abstract: A system for feeding a primary oxidant to an oxy-fired circulating fluidized bed (CFB) boiler. The system includes a plurality of bubble cap assemblies each comprising a stem and a bubble cap with at least one exit hole, each bubble cap connected via a stem to at least one windbox, the windbox containing at least one manifold. A plurality of pipes are provided, each pipe located within a bubble cap assembly with an open end located either at, above or below the exit holes of the bubble caps and an opposite end connected to the manifold located inside each windbox. Recycle gas is piped into the windbox, to the stem, and exiting from the exit holes located in the bubble cap into the CFB. Oxygen is piped into the manifold, through the pipes and exiting through the exit holes located in the bubble cap.

Abstract: A circulating fluidized bed (CFB) boiler comprising a reaction chamber. A bubbling fluidized bed (BFB) is contained within an enclosure within the lower portion of the reaction chamber and contains an in-bed heat exchanger (IBHX) that occupies part of the reaction chamber floor. At least one non-mechanical valve, which includes an opening between the CFB and BFB and independently controlled fluidizing means located both upstream and downstream of the opening, is used to control the heat transfer to the IBHX by controlling the solids discharge from the BFB to the CFB. The elevation of the bottom of the opening is at or above the elevation of the fluidizing means. A flow control barrier may be located downstream of the opening.

Abstract: An SNCR distribution grid for introducing a NOx reducing reactant into a flue gas flow. The grid is made of one or more elements which are formed by fluid-cooled tubes to which membrane pieces are attached, preferably by welding, to form conduits in between the tubes. The fluid-cooled tubes may be cooled by water and/or steam and the distribution grid is disposed in the flue gas flow. To admit the reactant into the flue gas, nozzles are provided in the membrane and the reactant is conveyed from a location external of the furnace or combustor enclosure, into the conduits so formed, and thence out into the Flue gas flow via the nozzles.