Abstract: The invention provides a means for more effectively adapting fluidized bed combustors for retrofit of existing boilers for burning of low grade inexpensive solid fuels. The operating discharge gas from a fluidized bed combustor is substantially lower in temperature from what exists at the furnace gas outlet of a conventional steam generator. Thus, outlet gas from fluidized bed combustors needs to be placed in the downstream gas path differently from conventional practice. The external combustors of the present invention permit placement of hot gas in the steam generator gas path where it can be effectively utilized. The invention also teaches how new steam generators can be configured advantageously to accommodate multiple fluidized bed combustors particularly as pertains to larger capacity steam generators in the 200 MW electrical and larger range.

Abstract: A domestic combustion appliance 1 has a body 2 having a distributor plate 14 for supporting a shallow fluidized bed 32. A primary boiler 34 forms part of a rear bounding wall for the fluidized bed 32, and a secondary boiler 50 is located downstream providing flue passages for exhaust gases. A window 10 is provided in the front wall 8 to give a visual effect for volatiles burning, in use, above the bed 32.

Abstract: A boiler or other fluidized bed apparatus has an outlet from the bed and an outlet from the gas stream downstream of the bed for removing material from the bed and from the gas stream. The material removed is passed to screening mechanism which separates materials into relatively larger particles and relatively smaller particles. The smaller particles are fed by conveyor to means feeding the bed. The larger particles are mainly ash which is discarded. Removal of material from the bed under load is provided for.

Abstract: A whirl chamber boiler plant for generation of steam includes a combustion chamber in which the fuel is burned in a whirl within the chamber. The bottom of the chamber slopes downwardly towards an inlet through which combustion air is admitted into the chamber. Fuel and inert material are admitted into the chamber adjacent the bottom thereof. The inlet is of a size suitable for fluidizing the inert material within the chamber. Boiler tubes built within the chamber provide for removal of heat from the chamber. Preferably the inert material is a grain-shaped ash of the type produced by the burning of the fuel. In one embodiment of the present invention, a portion of the ash contained in the gases exiting from the chamber is returned to the chamber.

Abstract: A fluidized combustion bed is divided by a hollow baffle into two regions which are fluidized at respectively higher and lower fluidizing velocities. Exhaust gases and elutriated particles leaving the larger region pass into the freeboard and around the baffle, the particles being deposited after such passage into the smaller region and the gases flowing into the baffle for exhaust.

Abstract: A system for the fluidized reinjection of fine particles (carryover) into a fluidized bed combustor. The carryover recirculation system includes a fluidized reinjection bed which is fluidized using clean gas from the induced draft fan outlet boosted by a small auxiliary fan. The fluidized fine particles can be reinjected into the fluidized combustor bed by either dense phase transport or by dilute phase transport.

Abstract: Sulfur is readily and efficiently removed from solid fuel in a boiler installation which comprises a hearth for burning and thereby gasifying the solid fuel, the hearth including a grid supporting a fluidized bed of the solid fuel spread thereover, and a tubular boiler body superimposed on, and integral with, the hearth, the boiler body including a lower portion receiving the gasified fuel from the hearth, an upper portion, a common transverse wall dividing the tubular boiler body into the lower and upper portions, and a burner extending into the upper boiler body portion near the dividing transverse wall and receiving a supply of secondary combustion air. A conduit connects the lower boiler body portion to the burner for feeding the gasified fuel therefrom to the burner, and dust removing and desulfurization cyclones in the conduit remove dust and sulfur from the gasified fuel.

Abstract: A fluidized bed heat exchanger in which an air distributor plate assembly is disposed within an enclosure for supporting a bed of particulate material. The plate assembly includes a plurality of horizontal, spaced tubes through which water is passed to cool the assembly. Air is passed from an air plenum through openings formed in the plate assembly to fluidize the particulate material. Insulation is disposed on the lower surface of the plate assembly to insulate the latter from the heat of the fluidizing air, and the upper surface of the plate assembly is insulated from the high temperatures occurring in the bed.

Abstract: A fluidized bed combustion system particularly suitable for use in a residential heating system comprising a fluidized bed combustor housing a combustion chamber wherein crushed fuel is burned to generate hot flue gas, a heat exchanger disposed outside of the combustor in the flow path of the flue gas, a particulate collector for removing fine particles entrained in the flue gas before the flue gas is vented to the atmosphere, and an induced draft fan for venting the flue gas to the atmosphere and drawing fluidizing air and recirculated flue gas through the combustion chamber. The combustor is uncooled and heavily insulated so as to provide a substantially adiabatic combustion chamber therein in order to minimize heat loss therefrom. Electric heating means are disposed within the fluidizing region of the combustion chamber to provide the capability of heating the slumped bed during shutdown to maintain bed temperature above the ignition point.

Abstract: There is disclosed the utilization of a fluidized bed as a combustion chamber for the combustion in an external combustion engine of the recyclable fuels magnesium, aluminum, and their hydrides and/or alloys. The combustion products serve in whole or in part as the inert media for the bed.

Abstract: A horizontal shell boiler has a horizontal furnace section which communicates with a flue gas transfer section at its end which transfers the flue gases from the furnace section to flue tubes extending horizontally through the space between the furnace section and the shell of the boiler. The furnace section is designed for fluidized bed combustion and has a flue gas transfer tube extending horizontally through its upper portion. The tube has hollow walls connected to the boiler fluid surrounding the furnace section and has apertures formed in its hollow wall through which furnace gases can enter the tube. The furnace gases after entering the flue gas transfer tube travel horizontally and do not entrain material of the fluidized bed.

Abstract: A boiler comprising a furnace box, having a peripheral wall, from which products of combustion pass to a smoke box wherein the furnace box comprises a lower compartment, means to establish a fluidized bed in the lower compartment, an upper compartment, an exit connected to said upper compartment for passage of products of combustion from said furnace box, means to isolate said lower compartment from said exit except by communication through said upper compartment and through a foraminous element located in the path of the products of combustion from said lower compartment to said upper compartment.

Abstract: In a method for decreasing the heat, impulse and material exchange in the direct vicinity of the walls of fluidized bed reactors, the flow resistance to the fluid (agitating medium) conducted through the fluidized bed will be increased in the vicinity of the walls to such an extent that the fluidized bed does not do much agitating in this region; moreover the components sticking out of the interior walls of the reactor serve to extend the rib-shapes from the wall projecting into the reaction space or parallel to the reactor wall while forming a slit with the latter. The components can be pre-fabricated segments and the distance of the annular components in the direction of flow of the fluid should at most be about half as great as the height of the ribs lateral thereto.

Abstract: In a combined generating plant utilizing a fluidized bed combustor in which coal or other carbonaceous fuel is burned at substantially atmospheric pressure, an external heat transfer unit is provided through which a portion of the hot solids of the fluidized bed is circulated through tubular channels. Clean air from an air compressor is passed through the heat exchanger unit around the outside of the tubular channels, so receiving heat through them from the hot solids circulating therethrough, and is expanded in a gas turbine. The flow of hot solids through the tubular channels is controlled independently of the operation of the combustor so as to accomodate varying loads on the generating units. Steam for a other uses is generated by a conventional boiler and superheater in the combustor.

Abstract: A fluidized bed heat exchanger in which a perforated plate is disposed within a housing for supporting a bed of particulate material. Air is passed through the plate to fluidize the particulate material and a mixture of air and additional particulate material is introduced to said bed and deflected into said bed in a manner to induce diffusion and circulation of the bed materials in the bed.

Abstract: Heat exchanger having a plurality of vertical pipes for upward passage of a first heat-exchanging medium, at least one compartment for passage of a second heat-exchanging medium through which compartment said pipes extend, a lower chamber through which said first medium passes and into which said pipes open for admission to the pipes of said first medium, and a flow distribution element adapted to distribute the flow of said first medium in said lower chamber to the pipes. A fluidizable particulate material is in operation, is maintained in a fluidized state in the pipes by the flow of the first medium. The pipes have inlet elements extending downwardly into said lower chamber with their lowermost ends open. Stabilization openings are provided into said inlet elements above said open lowermost ends thereof.

Abstract: A catalytic combustor for generating a mixture of steam and combustion gas is located downhole in an oil well, so that the gas mixture can be injected directly into the oil reservoir to displace heavy oils from the reservoir. There can be a single stage of catalytic combustion, or there can be a stage of thermal combustion followed by a catalytic stage. In either case the purpose of the catalyst is to drive the combustion to completion so that the gas mixture contains no soot that would plug the face of the reservoir.

Abstract: A method and apparatus for controlling steam production by controlling the flow rate of particulate solids from a fluidized bed combustion chamber through a vertical heat exchanger. The pressure drop across a section of the vertical heat exchanger is monitored and compared with a set point pressure drop. When the pressure drop being monitored falls below the set point pressure drop, a signal is provided to a particulate solids feed control means which then allows more particulate solids to be circulated through the vertical heat exchanger. The vertical heat exchanger receives heat from the particulate solids. The additional amount of particulate solids fed to the vertical heat exchanger are recirculated along with the previous amount of particulate solids through the heat exchanger into the fluidized bed combustion chamber. Because of the additional cooled particulate solids in the fluidized bed combustion chamber the temperature of the fluidized bed combustion chamber drops.

Abstract: In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.

Abstract: A grate characterized in that a fuel supporting and conveying surface is provided comprising at least one elongate channel having an open mouth and a bottom, the or each of said channels having a transverse cross-section which decreases in width in a direction extending away from the open mouth towards the bottom of the channel, air feed opening means to feed air to the interior of the channel at least in the region of the bottom thereof, and means mounting the channel to permit the channel to be vibrated to cause fuel to be conveyed along the channel and longitudinally of the grate.

Abstract: A mixture of fuel and air is introduced onto a catalytic combustion surface, preferably an inert, refractory substrate coated with trace amounts of a catalyst. Combustion is normally initiated by an ignition device, and proceeds spontaneously once the minimum temperature has been reached. Water is introduced directly onto the heated combustion surface, in metered quantities to prevent cooling below the desired minimum combustion temperature, thus generating a continuous flow of steam at a pressure equal to the inlet pressure of the air, fuel and water. The quantities of air, fuel and water may be varied proportionately to produce rapid variation in the volume, temperature and pressure of the steam generated, a function that may be greatly facilitated by the choice of a combustion element having a low thermal mass. Both the catalytic combustion of fuel and the vaporization of inert working fluids can occur over a wide range of temperature and pressure conditions.

Abstract: A fluidized bed furnace (10) for generating steam (26) is designed to operate over a given load range, for example from 50% of full load to maximum capacity rating (MCR). The air distributor (12) is designed with a constant pressure drop restriction means or "float" (36) in each air inlet (18). As the load varies, the pressure drop across the float (36) will remain constant, reducing the overall fan horse power requirements.

Abstract: This invention relates to boilers more particularly to shell boilers and improvements in their operation.In more detail this specification describes and claims a boiler comprising a housing, an inlet for leading a fuel or a fuel/gas mixture into a combustion chamber, at least one array of pipes in series with the combustion chamber, an exit for leading exhaust gases away from the boiler and means for cooling the pipes and the combustion chamber, characterized in that the boiler includes a catalyst disposed in such a position that at least a proportion of any unburnt fuel leaving the combustion chamber undergoes catalytic combustion.

Abstract: A fluidized bed combustor comprises a housing having a chamber therein with a top having a discharge for the gases which are generated in the chamber and a bottom with a discharge for heated fluid. An assembly is arranged in the lower portion of the chamber and the assembly includes a lower plate which is mounted on a support flange of the housing so that it is spaced from the bottom of the chamber and defines a fluid plenum between it and the bottom of the chamber for the discharge of heated fluid. The assembly includes a heat exchanger inlet plenum having tubes therethrough for the passage of fluidizer air and a windbox above the heat exchanger plenum which has a distributor plate top wall. A portion of the chamber above the top wall defines a fluidized bed.

Abstract: An arrangement for the burning of materials having components that are difficult to burn out and which tend to be adhesive upon heating. A turbulent layer is formed and connected with a combustion chamber for burning the materials. Combustion air is distributed to the turbulent layer and the combustion chamber for removing a portion of heat that is released, so that the combustion chamber retains a minimum temperature above a predetermined level. A contact chamber is connected to the turbulent layer and communicates with the combustion chamber. A constricting collar is provided with nozzles for applying combustion air.

Abstract: A compact catalytic combustor for generating steam downhole in an oil reservoir has steam generating tubes that are attached to a metal catalyst support. The metal support comprises sheets of metal that are spaced apart and transverse to the tubes. Heat from combustion is generated on the metal sheets and is conducted to the steam generating tubes. The steam is injected into the oil reservoir. The combustion gas is vented to ground level.

Abstract: The present invention is directed to the extraction of energy values from l shale containing considerable concentrations of calcium carbonate in an efficient manner. The volatiles are separated from the oil shale in a retorting zone of a fluidized bed where the temperature and the concentration of oxygen are maintained at sufficiently low levels so that the volatiles are extracted from the oil shale with minimal combustion of the volatiles and with minimal calcination of the calcium carbonate. These gaseous volatiles and the calcium carbonate flow from the retorting zone into a freeboard combustion zone where the volatiles are burned in the presence of excess air. In this zone the calcination of the calcium carbonate occurs but at the expense of less BTU's than would be required by the calcination reaction in the event both the retorting and combustion steps took place simultaneously. The heat values in the products of combustion are satisfactorily recovered in a suitable heat exchange system.

Abstract: A fluidized bed reactor e.g. for the burning of fuels of different calorific values. The bottom part of the combustion chamber is divided into an outer and an inner fluidization zone by a partition wall adjacent to the distributor plate. Heat transfer surfaces are disposed in the outer fluidization zone. Heat can be withdrawn from the outer fluidization zone which is activated when burning fuel having a high calorific value. When burning fuel of lower calorific value the outer fluidization zone is not operated. The inner fluidization zone will be in operation in both cases. The supply of fluidizing gas to the second fluidization zone is controlled in order to maintain predetermined conditions in this zone.

Abstract: A fluidized bed call (10) having a static ignition bed (18) of inert heat storage particles (50) disposed immediately beneath and adjacent to a fluidizing region (44) wherein fuel particles are combusted, characterized in that the heat storage particles (50) are generally spherical in shape, each particle having a plurality of protuberances (52) extending outwardly from the surface of the particle a preselected length thereby maintaining a minimum spacing, equal to the preselected length of the protuberances, between neighboring spherical particles within the static ignition bed thereby ensuring that sufficient void space (54) exists within the static ignition bed for the fluidizing air to flow upward through the static ignition bed into the fluidizing region without an excessive pressure drop and for the fuel particles to laterally penetrate the static ignition bed.

Abstract: A fluidized bed heat exchanger in which a bed of particulate material is supported on a grate in a housing and air is passed through the grate and the particulate material to fluidize the bed and promote the combustion of combustible material contained therein. A baffle system is disposed in the housing for impacting with the entrained particulate material in the air and gaseous products of combustion to remove the latter material and permit it to fall by gravity back to the bed. A series of tube sections are provided in the housing for directing the air and gaseous products to the baffle means and gases are injected from the proximity of the baffle means downwardly towards the bed.

Abstract: A process and pressurized, gasification reactor apparatus for converting combustible carbon containing materials such as coal char and other carbonaceous solids or carbonaceous solids/heavy oil combinations to an intermediate heating value fuel gas. The gasification reactor includes an insulated fluidized bed reactor chamber, an upper reactor housing for a freely suspended bayonet bundle type heat exchanger for (a) superheating incoming saturated steam and (b) cooling outgoing high temperature product gas, and a lower reactor housing structure which includes a free-floating, conically-shaped perforated plenum chamber. The superheated steam and oxygen are premixed with the plenum chamber before being pressure directed into the fluidized bed reactor chamber for mixture and combustion with the incoming combustible carbon containing materials such as coal char. After reaction of the superheated steam, oxygen and coal char in the fluidized bed reactor at temperatures ranging from 900.degree. F. to 1750.degree. F.

Abstract: A loose fitting movable cover plate (36), suitable for the severe service encountered in a fluidized bed combustor (10), restricts the flow of solids into the combustor drain lines (30) during shutdown of the bed. This cover makes it possible to empty spent solids from the bed drain lines which would otherwise plug the piping between the drain and the downstream metering device. This enables use of multiple drain lines each with a separate metering device for the control of solids flow rate.

Abstract: There is provided a fluidized bed combustor comprising an economizer contained in an upper interior portion and indirect heat exchange conduits suspended in the lower interior portion of the fluidized bed combustor in spaced relation to the interior surfaces of the fluidized bed combustor.

Abstract: A fluidized bed boiler system and a manner of operating the same is provided wherein a fluidized particulate bed in which solids are not recycled is utilized. High temperature flue gas is directed to a boiler means. A portion of both the high temperature and a low temperature gas stream are recycled to a fluidizing gas stream for fluidizing the particulate bed.

Abstract: Apparatus and process for quenching and cooling reactor effluent. The apparatus includes a section for introducing relatively cool particulate solids into a hot effluent stream to effect initial quenching and a section to further cool the composite quenched effluent and solids. The process employs relatively cool particulate solids to quench hot effluent and indirect heat exchange between water and the quenched effluent-solids mix to generate high pressure steam and further cool the mix.

Abstract: A fluidized bed reactor in which a grate is disposed in a housing for receiving a single bed of particulate material. The interior of the housing below the grate is divided into a plurality of zones and air is selectively passed through portions of the grate to fluidize corresponding portions of the bed above the zones. A plurality of pipes are provided in the bed for receiving excess particulate material accumulating in various portions of the bed and for blowing air into said latter portion, to reduce the build-up of particulate material in the bed.

Abstract: A shaft furnace is provided for gasifying granular fuels in a fluidized bed. Such a furnace comprises a gasification zone containing the fluidized fuel bed and an overlying gas cooling zone having surfaces cooled by the tube surfaces of a radiation tube boiler. By providing such a gas cooling zone with a cross-sectional area substantially greater than that of the gasification zone, the gas effluent is cooled in such a manner that residues entrained in the effluent do not sinter onto the surfaces of the equipment in the subsequent path of the effluent.

Abstract: A fluidized bed combustion device adapted for use with a boiler has an air distributor consisting of a row of generally horizontally oriented, apertured sparge pipes or tubes disposed in a bed of inert particulate material. The center pipes in the row are connected to a start-up burner for receiving heated combustion products and excess air and the outer pipes in the row are connected to selectively receive air through a separate delivery path. During start-up and low load conditions, only the center pipes are pressurized and so that only the center portion of the bed is fluidized to minimize the heat input requirements. Once the central portion of the bed has been heated to the required temperature, primary fuel is delivered to sustain combustion without the start-up burner. At the completion of the start-up process and during high fire conditions all of the tubes are pressurized to fluidize the entire bed.

Abstract: A vapor generating system in which a furnace section is provided that is formed by four upright walls, the lower portion of two opposed walls being slanted inwardly to form a hopper portion. A plurality of openings are formed in each of the opposed walls immediately above its slanted portion. Two gasifiers extend adjacent said opposed wall portions, respectively, and surround the respective slanted wall portions and openings, so that the respective interiors of the gasifiers communicate with the openings. A bed of adsorbent material is supported in each gasifier for adsorbing the sulfur generated as a result of the gasification of fuel introduced into the gasifier and air is passed through the bed of adsorbent material to fluidize said material so that, upon combustion of said fuel, a substantially sulfur-free product gas is produced which passes from the gasifier, through the openings and into the furnace section.

Abstract: A fluidized bed combustion device adapted for use with a boiler has an air distributor consisting of a plurality of rows of generally horizontally oriented, apertured sparge pipes disposed in a bed of inert particulate material. The rows of pipes are vertically spaced apart with the upper row being connected to a start-up burner for receiving heated combustion products and excess air and the lower rows of pipes are connected to selectively receive air or inert gases through a separate delivery path. During start-up and low load conditions, only the upper row of pipes is pressurized and so that only the upper portion of the bed is fluidized to minimize the heat input requirements. Once the upper portion of the bed has been heated to the required temperature, primary fuel is delivered to sustain combustion without the start-up burner. At the completion of the start-up process and during high fire conditions all of the rows of tubes are pressurized to provide a deeper bed of fluidized material.

Abstract: Heat exchanger for gases, comprising a vertical shaft with upward flow of gas between rows of staggered horizontally disposed sets of tubes, downwardly restricted by a gas penetrable bottom (2) and upwardly by the uppermost set of tubes, and over its entire vertical length containing a granular material (7) which is kept in motion by the essentially vertically upward gas stream. The heat exchanger is characterized therein that the ratio between the diagonal free opening a and the horizontal free opening b between the tubes (4) in the set of tubes lies within the range 0.45:1-0.9:1 for controlling and restricting the vertical movement of the grains in the heat exchanger, thereby obtaining an approximately continuous temperature gradient in the gas-grain mixture over the entire height of the heat exchanger.

Abstract: A fluid bed heater or vaporizer unit has a generally cylindrical configuration with its major axis horizontally disposed. A mixture of coal and limestone is fed into the elongated fluidized bed within the unit for combustion; the limestone being present to minimize sulfur emissions due to the sulfur present in the coal. The wall of the unit in the region of the freeboard is lined with horizontally disposed heat exchange tubing. The delivery of air to the fluidized bed is regulated so as to establish a combustion zone of high turbulence and one or more heat transfer zones of lower turbulence. A plurality of heat exchange tubes are located in the heat transfer zone or zones and within the expanded bed level of the fluidized bed but above the region occupied by the slumped bed. Economizer heat exchange coils may be located in the passageway for exhaust gases.

Abstract: An assembly and method for heating a fluidized bed combustion chamber to ignition temperature, wherein a heated gas flows through heat exchange tubes extending into the fluidized bed to provide sufficient heat for raising the temperature of the bed material and the combustion air to allow for ignition of the combustion fuel. A conduit system is provided for selectively recycling combustion air through the combustion chamber during the ignition process.

Abstract: An integral generator/gasifier system in which a vapor generator is provided that includes an upright furnace section and a plurality of nozzles, each having one end registering with the interior of the furnace section. A gasifier extends adjacent to the furnace section and supports a bed of adsorbent material for the sulfur generated as a result of the gasification of fuel introduced to the gasifier. Air is passed through the bed of adsorbent material to fluidize said material so that, upon gasification of the fuel, a substantially sulfur-free product gas is produced. The other ends of the nozzles communicate with the gasifier so that the product gas passes from the gasifier through the nozzles and into the furnace section for combustion.

Abstract: In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.

Abstract: In a fluidized boiler system, the rate of fuel flow and bed depth are simultaneously controlled in response to variations in a load demand signal representing the need for steam output from the system. When the load demand changes, the rate of fuel flow is varied accordingly to provide a change in the bed temperature to thus provide a rapid response to the change in the demand signal. At the same time, the system changes the rate of flow of limestone to the bed and the rate of removal of spent particulate material of the bed to change the bed depth to respond more slowly to the change in the demand signal. As the depth of the fluidized bed approaches a value corresponding to the demand signal, the temperature of the bed will change back toward a median value.

Abstract: A fluidized bed heat exchanger in which a perforated plate is disposed within a housing for supporting a bed of particulate material. Air is passed through the plate to fluidize the particulate material and nozzles are provided for distributing air across the inlet end of a drain pipe for the spent particulate material to insure a continuous draining of the material.

Abstract: A system for supporting a fluidized bed in a boiler in which a plurality of support frames are supported in an abutting relationship spanning the interior of the boiler. One or more of the support frames are connected or attached relative to each other and to their supports in a manner to permit limited relative movement between the frames and between each frame and its support. A grid is supported by each frame and is connected or attached thereto in a maner to permit limited movement of the grid relative to the frame.

Abstract: A heat exchanger is mounted in the upper portion of a fluidized combusting bed for the control of the temperature of the bed. A support, made up of tubes, is extended from the perforated plate of the fluidized bed up to the heat exchanger. The tubular support framework for the heat exchanger has liquid circulated therethrough to prevent deterioration of the support.

Abstract: A first atmospheric bubbling fluidized bed furnace is combined with a second turbulent, circulating fluidized bed furnace to produce heat efficiently from crushed solid fuel. The bed of the second furnace receives the smaller sizes of crushed solid fuel, unreacted limestone from the first bed, and elutriated solids extracted from the flu gases of the first bed. The two-stage combustion of crushed solid fuel provides a system with an efficiency greater than available with use of a single furnace of a fluidized bed.