Combustion Engineering, Inc.

Other

Alstom Technology Limited

Michael C Tanca

Erik G Dahlquist

Sune Flink

Paul R Thibeault

Lawrence J Peletz, Jr

Scott L Darling

Ernest L Hartman

Thomas Richard Bober

Mark S Zak

Thomas F Begina

Thomas R Bober

Jeremy A Ryser

A grate assembly for a fluidized bed reactor includes a plurality of parallel air ducts extending side-by-side in a substantially horizontal plane and defining spaces therebetween through which coarse material from the fluidized bed descends. A plurality of nozzle assemblies is attached to each air duct for supplying fluidizing air from within the air duct into the fluidized bed. Each of the nozzle assemblies includes a nozzle formed from a tube having an inlet end in fluid communication with the air duct, and an outlet end in fluid communication with the inlet end. An orifice is disposed at the outlet end of the nozzle, and the nozzle is bent proximate the outlet end to direct a primary direction of a stream of fluidizing air flowing from the orifice toward the air duct such that an angle &#x3b8; between the primary direction and the substantially horizontal plane formed by the air ducts is between about 30 to about 90 degrees.

Fuel fluidizing nozzle assembly

A method is provided which refurbishes a Rankine cycle vapor generator initially having a plurality of Rankine heaters for supporting a Rankine cycle subsystem. The method removes at least one of the Rankine heaters, and replaces the at least one removed Rankine heater with a non-Rankine heater for a Kalina cycle subsystem. The vapor generator comprises a first plurality of tubes for receiving a first working fluid, and a second plurality of tubes for receiving a second working fluid. The first plurality of tubes are directed along a first path exposed to heat from a heat source to increase the temperature of the first working fluid within the first plurality of tubes. The second plurality of tubes are directed along a second path exposed to heat from the heat source to increase the temperature of the second working fluid within the second plurality of tubes. The first plurality of tubes supply the heated first working fluid to components of a Rankine cycle subsystem and the second plurality of tubes supply the heated second working fluid to components of a Kalina cycle subsystem.

Refurbishing conventional power plants for Kalina cycle operation

A fluidized bed combustion system is disclosed and in particular a fluidized bed combustion system particularly well suited for the combustion of oil shale, generating steam thereby. The fluidized bed combustion system includes a furnace volume having a multi-chambered upper segment thereof, a deentrainment zone, a fluidized bed having a plurality of isolatable segments thereof, a fluidized bed ash cooler having a plurality of isolatable segments thereof wherein the fluidized bed ash cooler is in fluid communication with the furnace volume, a fuel supply means in fluid communication with the furnace volume for delivering oil shale thereto for combustion therein, a backpass volume defined by a plurality of backpass wall tubes integral to a thermodynamic steam cycle and in fluid flow relation with the furnace volume and a plurality of circulatory fluid flow paths integral to a thermodynamic steam cycle and operative to conduct the flow of steam or water therethrough.

Oil shale fluidized bed

A control scheme for large circulating fluidized bed steam generators (CFB) wherein direct control is effected therewith over the temperature of the large circulating fluidized bed steam generators (CFB) and wherein independent control is effected therewith over the final superheat steam temperature of the large circulating fluidized bed steam generators (CFB) as well as over the final reheat steam temperature of the large circulating fluidized bed steam generators (CFB).

Control scheme for large circulating fluid bed steam generators (CFB)

A method for enhancing the minimization of NO.sub.x control in a circulating fluid bed steam generator into which there is injected fuel, fluidizing air, a lower level of combustion air and an upper level of combustion air. The fuel is injected at a first location, the fluidizing air is injected at a second location, the lower level of combustion air is injected at a third location and the upper level of combustion air is injected at a fourth location. In order to enhance the minimization of NO.sub.x control within a circulating fluid bed steam generator the lower level combustion air as well as the upper level combustion air are each biased in the horizontal plane as well as the vertical plane so as to thereby control the lower level combustion air flow and the upper level combustion air flow such that local stoichiometries within the circulating fluid bed steam generator are maintained within a range of 70% stoichiometry to 90% stoichiometry.

Circulating fluid bed steam generator NO.sub.x control

A kraft black liquor gasification system is provided with a hot flue gas generator which serves both as a means for generating a hot flue gas to warm-up the gasifier in preparation for start-up and as a means for generating an inert purge gas to purge the gasifier of flammable gases in the event of an emergency trip of the gasifier. A control system controls the operation of the burner during warm-up in response to the gasifier temperature and during the purge in response to the purge gas composition and temperature.

Black liquor gasification with integrated warm-up and purge

A fluidized bed system which includes a housing and a floor comprising a plurality of generally parallel tubes joined by fins intermediate adjacent tubes. A plurality of nozzle assemblies extend generally vertically in mutually parallel relationship from the floor. Each of the nozzle assemblies includes a generally cylindrical body having a centerline disposed in generally perpendicular relationship to the floor and each of the bodies includes a plurality of heads extending generally radially therefrom at an axial extremity thereof remote from the floor. In some embodiments of the invention each of the heads are uniformly spaced around the circumferential extent of each of the bodies and each of the heads is generally cylindrical and has a centerline. Each of the centerlines of the heads may be disposed at an angle with respect to a horizontal plane and the angle may be approximately twenty degrees. In some forms of the invention some of the nozzle assemblies each have four heads and some of the nozzle assemblies have two heads. In other embodiments all of the nozzle assemblies have two heads. In other embodiments all of the nozzle assemblies have four heads.

Fluidized bed with improved nozzle construction

A black liquor gasification system intended for use as a replacement for a Tomlinson cycle, Chemical Recovery Unit, and which operates at a temperature below the ash melting temperature thereby removing the potential for smelt-water reactions and explosions. The subject black liquor gasification system is based on the use of a circulating fluidized bed operating at atmospheric pressure that produces dry, recoverable salts as well as low calorific gases to be used within the paper-making process.

CFB black liquor gasification system operating at low pressures

A slag tap system for a pressurized gasifier system that includes a reaction vessel and a pressure vessel in surrounding relation to the reaction vessel. The slag tap system includes a slag tap portion through which slag is discharged from the reaction vessel, mounting means for mounting the slag tap portion in supported relation within the reaction vessel, water inlet means operatively connected to the slag tap portion for introducing water thereinto, water outlet means operatively connected to the slag tap portion for discharging water therefrom after the passage of the water through the slag tap portion, a slag tank mounted in supported relation within the pressure vessel below and in spaced relation to the slag tap portion and operative to receive the slag for quenching therewithin after the slag has been discharged from the slag tap portion, and discharge means operatively connected to the slag tank for effecting the discharge therefrom of the slag after the slag has undergone quenching within the slag tank.

Circular slag tap for a gasifier

Black liquier gasification process operating at low pressures using a

An entrained flow coal gasifier having a combustor zone (16) and a reductor zone (18) separated by a centrally located baffle (14). The baffle (14) covers the projected plan area of a slag tap (44) whereby cool slag falling from the reductor (18) will be heated before flowing through the slag tap.

Two stage slagging gasifier

A pressurized coal gasification system having double wall containment vessels (2,10) is disclosed. The gasification vessel (2) is provided with a gas tight water seal (36) for connecting the lower end of the inner water-cooled vessel (4) with the bottom supported slag tank (32). The seal (36) prevents gas leakage between the vessel interior and the pressurized annular volume (24) formed between the inner and outer gasification chambers (4,6). A flow of clean, particulate-free product gas (60) is routed into the contiguous annular volume (24,26,28) formed between the inner water-cooled gas directing members (4,20,12) and the outer, pressure containing members (6,22,16) to prevent either leakage of raw product gas into the annular volume or dilution of the product gas (46) by leakage of the sealing gas (60) into the hot product gas flowstream.

Coal gasification system with product gas recycle to pressure

A first portion (50) of a sulfur and nitrogen-bearing carbonaceous fuel is gasified in a gasification reactor (20) in the presence of a reducing atmosphere of air to produce a hot, char-containing, carbon-monoxide-rich fuel gas (42) having a low Btu content. After cooling, the char-containing carbon-monoxide-rich fuel gas (42) is introduced into a steam generating furnace (10) and combusted therein with a second portion (40) of the carbonaceous fuel in the presence of at least sufficient additional air to substantially complete combustion whereby a hot flue gas is produced. A sulfur-capturing material (60) is introduced into both the gasification reactor (20) and the combustion zone of the steam generating furnace (10) to absorb a substantial portion of the sulfur-containing gases produced during the gasification and combustion processes. By combusting the second portion of the carbonaceous fuel together with the cooled, carbon-monoxide rich, low Btu content fuel gas, nitrogen oxide produced during combustion in the steam-generating furnace (10) is also reduced.

Integrated process for gasifying and combusting a carbonaceous fuel

A wet-bottom, solid fuel gasifier has a slag tap through which a portion of the product gas is back-flowed through the slag tap to maintain the temperature of the slag hot enough to maintain continuous slagging. The reverse flow of the product gas portion is controlled by the negative pressure generated in the throat of the gasifier.

Slag tap gas flow inducement in wet-bottom furnaces

A method of operating an entrained flow coal gasifier (10) via a two-stage gasification process. A portion of the coal (18) to be gasified is combusted in a combustion zone (30) with near stoichiometric air to generate combustion products. The combustion products are conveyed from the combustion zone into a reduction zone (32) wherein additional coal is injected into the combustion products to react with the combustion products to form a combustible gas. The additional coal is injected into the reduction zone as a mixture (60) consisting of coal and steam, preferably with a coal-to-steam weight ratio of approximately ten to one.

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Tariffville, CT, United States of America

Michael C Tanca