Abstract: A fluidized bed reactor and a method of operating same in which three discrete chambers are formed in a housing and a main fluidized bed containing particulate fuel and adsorbent material is established in a first chamber. The fluidizing air in the first chamber entrains a portion of the particulate material as it passes through the bed and the first chamber. A portion of the particulate material that is entrained by the air is separated and introduced to additional grid means disposed in a second chamber to establish a bed of the separated particulate material. Air and a cooling fluid are passed through the bed of separated particulate material for cooling same. The cooled separated particulate material is passed to a third chamber for storage and the latter is connected to the main fluidized bed for selectively reinjecting the cooled separated particulate material back to the main fluidized bed.

Abstract: An ignition burner for igniting fuel oxygen-containing gas mixture. The burner utilizes a central electrode and means for supplying the electrode with both a low velocity flow and a high velocity flow of combustible gases to the electrode to form a first flame. The first flame is surrounded by a plurality of nozzles that supply additional fuel and oxygen-containing gas to form a large ignition flame.

Abstract: The invention relates to method and apparatus for the combustion of large solid fuels. In order to improve the beneficial effect of sound on combustion are a bed of the fuel located on a grate, the bed of fuel is exposed to a high particle velocity of a sound positively produced by an external low frequency sound generator, the frequency of which is determined by the sound generator, to provide a reciprocating movement of combustion air and combustion gas through the fuel bed. The dimensions of the grate in a plane transverse to the reciprocating movement of combustion air and combustion gas are less than a quarter of the wave length of the sound generated by the sound generator.

Abstract: A fluidized bed combustion apparatus in which in the free-board above the bed at least one system of plates or baffles inclined with respect to the vertical is arranged so that at least one upwardly directed channel having internally at least one group of two opposed arrays of superimposed inclined plates is formed, which plates at least alternately extend obliquely downwardly from the outside to the inside and are closely connected with the outer boundary of the channel. Preferably all plates of each array extend obliquely downwardly at an angle with the vertical within 20.degree.-50.degree. from the outside to the inside from a vertical wall defining said channel whereas the plates of the one array are off-set over a distance "s" in the vertical direction with respect to the plates of the other array.

Abstract: During the operation of an oxygen-fuel burner the supply of fuel is reduced to generate an oxygen-rich low velocity flame. The excess oxygen of the flame is heated by the flame and oxidizes any slag accumulated on or about the burner.

Abstract: The invention relates to a method of igniting, upon start-up, a combustion chamber (8) in a power plant with combustion of fuel in a fluidized bed (14). The air flow through the nozzles (13) of the combustion chamber bottom (12) for fluidization of the bed (14) and for combustion of the fuel can be reduced upon start-up; bed material, which is heated to the ignition temperature of a start-up fuel, is transferred from a storage container (40) to the combustion chamber (8), and fuel is supplied to the bed (14). In those cases where the air flow has been reduced during the transfer of the bed material, it is increased again when the fuel is supplied. The invention also relates to a power plant having means for temporarily bypassing the nozzles (13) of the combustion chamber bottom (12) while transferring hot bed material from a storage container (40) to the combustion chamber (8), and a fuel system (30-38) for the supply of fuel to the combustion chamber (8).

Abstract: A combustion process is disclosed for burning a fuel containing sulfur characterized by low sulfur and particulate emission and formation of solid, non-toxic sulfur compounds. The process comprises mixing the sulfur containing fuel with an additive capable of reacting with sulfur; burning the mixture in a first combustion stage with less than 75% theoretical air and at a temperature below the melting point of the ash, but sufficiently high to cause reaction between the additive and any sulfur in the fuel to facilitate removal of the sulfur compounds formed; passing combustible fuel gases and particulates from the first stage to one or more further stages to complete the combustion of the fuel; and oxidizing, in a separate zone, sulfur compounds formed in the first reaction zone by reaction between the additive and the sulfur in the fuel to form non-toxic sulfates.

Abstract: A melting system which is constructed of a melting furnace having a substantially cylindrical furnace body, a blast pipe for introducing air from a pre-arranged air supply source into the furnace body, a particle carbon material supplying apparatus, a particle carbon supplying conduit with an outlet in the tuyere, a screw type material discharging equipment, disposed under the particle carbon supplying apparatus, being connected to the tuyere, and a branch pipe branched off the blast pipe and connected to the particle carbon supplying conduit. This characteristic branch pipe is provided with, in the middle way thereof, a pressure giving device and preferably a bypass passage bypassing the pressure giving device.

Abstract: A composition comprising a particulate fuel, typically pulverized coal, carried in water is formed such that it is readily able to be pumped without adding emulsifiers or lubricants to the composition. The composition typically includes at least 25% water and preferably 30 to 50% water. The composition is pumped to a burner 2 and is atomized therein, typically by means of a stream of oxygen supplied through a passage 6 in the nozzle 6 of the burner. This oxygen is taken from that supplied to a further passage for supporting combustion of the particulate fuel. A relatively short and intense flame can be produced at relatively low coal concentrations in the composition such that the need to use expensive emulsifiers etc. is avoided.

Abstract: A system for removal of tramp or trash material from a single fluidized bed contained within a single vessel used to incinerate or pyrolyze solid fuel, the system comprises a gently sloped, skewed or serpentine stationary bed support and air distributor structure which distributes air in a fashion so as to uniformly fluidize a shallow bed of variable depth across the slope thereof without internally circulating the bed, and at the same time cause non-combustible tramp or trash material (e.g. pieces of steel, rocks, clumps, etc.), to be removed from the bed without passing to a location either above or beneath the bed. The angle of slope is strictly controlled. During periods of non-fluidization and/or non-use, the bed material is kept from falling into the air distribution plenum below the bed support structure by hollow bed containment structure disposed at sites below the bed support structure.

Abstract: A ring-gap nozzle for distributing a fluid medium over a plate, for instance over a bottom plate in a fluidized bed dryer, having two dish-shaped pressed parts suiting to each other complementarily being assembled in facing relationship and nested into each other and forming a ring gap through which the medium, deflected by 90.degree. or more, flows to the bottom plate, preventing both the settling of the product to be treated in the fluidized bed dryer on the plate as well as the reflux of the product backwardly into the nozzle when the flow of medium is cut off. This type of nozzle is simple to manufacture and does close the passage without any complicated manipulation automatically.

Abstract: A system and method of delivering dried fine fuel. Moist coal is extracted from a source and initially dried to a moisture content of five percent by a gas fired dryer plant. The initially dried fuel is then transported to a central processing site whereat the coal is pulverized and further dried and fed to a storage silo. Tractor-trailers receive the dried fine coal from the storage silo and transport same to the end user's site. The trailer is disconnected from the tractor and is utilized as a storage tank as the coal is withdrawn therefrom on an as-needed basis. A fuel injector coupled to a variable rate feeder is utilized in one embodiment to convey the dried fine fuel from the trailer to the burner.

Abstract: An improved splitter for use with a coal-fired furnace utilizing a low load burner in which a splitter is provided in the main conduit leading from the pulverizer for splitting the stream of coal and air into two separate streams which are then fed to separate nozzles communicating with the furnace. The splitter includes a damper assembly defining a gap which can be adjustable and including a plurality of projections which prevent coal slippage along the damper blade.

Abstract: An air-purged burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired without the coking thereof on the burner components. The air-purged burner is designed for the firing of pulverized solvent refined coal in a tangentially fired boiler.

Abstract: A pulverized coal-air stream or auxiliary air stream discharging into a furnace (1) from a delivery pipe (12) is deflected away from the longitudinal axis of the delivery pipe by directing a working fluid stream, preferably air or flue gas, against the coal-air or auxiliary air stream as it approaches the outlet of the delivery pipe so as to impinge thereagainst at an angle of substantially ninety degrees. The resulting angle of deflection of the coal-air or auxiliary air stream away from its longitudinal axis is controlled by varying the momentum of the working fluid stream impinged against it.

Abstract: Wood-waste products, such as wood shavings, wood chips and sawdust, are burned in an apparatus having a waste burner comprising an elongated cylinder in which fuel and air are mixed and ignited before entering an enlarged combustion chamber. The waste burner is characterized by an elongated cylinder having a length substantially larger than its diameter so that the fuel can be heated to a temperature sufficient to pyrolyze volatiles and initiate combustion in the cylinder. A wood-waste burner apparatus is also provided and comprises the waste burner of the invention and a combustion chamber for receiving unburned fuel and combustion products emanating from the burner. A process for burning wood-waste products is also provided. The invention is especially well suited for retrofitting packaged boilers to accommodate wood-waste fuels.

Abstract: A low BTU, low volatile content, low carbon and high ash fuel is combusted in a combined shaft kiln combustor and fluidized bed combustor to generate heat which is converted to useful energy. The fluidized bed combustor is mounted vertically above the shaft kiln combustor. A venturi is provided in a passageway connecting the shaft kiln combustor and the fluidized bed combustor to produce a gaseous stream moving at a velocity sufficient to separate finer particles from the low BTU, low volatile content, low carbon and high ash fuel so that the coarser particles are burned in the shaft kiln combustor and the finer particles are burned in the fluidized bed combustor.

Abstract: The air dispersion plate at a lower part of a fluidized bed combustion furnace is provided with a large number of air injection nozzles uniformly distributed therethroughout and made of a porous refractory material having good air permeability and high heat and wear resistances. All of the fluidizing air supplied into the wind box below the dispersion plate is injected through these nozzles into the combustion chamber to fluidize the fluidizable material, which, after combustion is stopped, cannot flow through the nozzles into the wind box to cause heat damage and contamination therein and in the air supply pipe.

Abstract: Description is of fluidized bed shell boiler arrangements in which the sides of the bed within the furnace tube are generally vertical, being provided by vertical walls within the furnace tube. The bed walls may include water tubes or be substantially vertical portions of arcuate panels mounted within the furnace tube. Fluidizing gas is fed to fluidizing gas ducts communicating with the bed from a plenum chamber including paddles movable into positions closing off at least some of the ducts during initial start up of the boiler to reduce the amount of combustible gas (or hot gases) fed to the ducts when heating the bed to its operating temperature. The ducts may be formed by mounting halfround or U-shaped member on the bottom of the furnace tube, the ducts tapering along their lengths such that the gas passing into the bed exits at substantially the same velocity across the width and length of the bed.

Abstract: A method of burning a coal-water slurry capable of being retrofitted to oil and gas fired industrial and utility steam boilers or as original equipment in new units using essentially pure oxygen, oxygen-enriched air or hydrogen-oxygen mixtures as the atomizing fluid in a burner atomizer.

Abstract: This burner is so designed as to be capable of operating in a stable manner with no risk of explosion with pure oxygen or air highly enriched with oxygen as the reactant. In one embodiment, a stream of oxygen is delivered through a central tube 4A which terminates in a divergent annular diffuser 30. A mixture of air and pulverized coal is delivered in an intermediate ring 15 around this diffuser and an annular stream of whirling oxygen is delivered in an outer ring 16. Application in indirect heating furnaces, furnaces in which slag exists and cement-making furnaces and in cases where special atmospheres (for example reducing atmospheres) are desired.

Abstract: A system for removal of tramp or trash material from a single fluidized bed contained within a single vessel used to incinerate or pyrolyze solid fuel, the system comprises a gently sloped, skewed or serpentine stationary bed support and air distributor structure which distributes air in a fashion so as to uniformly fluidize a shallow bed of variable depth across the slope thereof without internally circulating the bed, and at the same time cause non-combustible tramp or trash material (e.g. pieces of steel, rocks, clumps, etc.), to be removed from the bed without passing to a location either above or beneath the bed. The angle of slope is strictly controlled. During periods of non-fluidization and/or non-use, the bed material is kept from falling into the air distribution plenum below the bed support structure by hollow bed containment structure disposed at sites below the bed support structure.

Abstract: Process and apparatus for supplying combustible material to a fluidized bed in a vessel connected to a separating device for the solid particles entrained with the smoke and containing a certain proportion of unburnt matter, the particles recovered being recycled into the fluidized bed. During a normal operation of the fluidized bed supplied with combustible matter, the solid particles recovered in the separating device are accumulated in a silo and periodically, the supply of combustible matter is stopped and the particles accumulated in the silo are recycled into the fluidized bed with a regulated flow rate, so that the combustion of the unburnt matter contained in the recycled particles maintains the temperature of the fluidized bed at the desired level. The exothermic reaction is maintained alternately by the combustion of the combustible matter in the normal operating phase and by the combustion of the unburnt matter in the recycling phase.

Abstract: A fast fluidized bed reactor, comprising an upright reaction chamber for containing a bed of granular material, the chamber having a cylindrical upper region and a lower region; a feeder for feeding matter into the lower region; apparatus for supplying pressurized air to the reaction chamber to fluidize the granular material in the circulating regime, whereby a portion of the granular material is entrained into the upper region; apparatus for tangentially supplying pressurized air to the upper region, the second stream of air being supplied, and the reactor being constructed, in a manner to provide a Swirl number of at least 0.

Abstract: A reaction chamber with a fluidized bed encloses two superposed cyclone separators connected in series. In order to prevent combustion gases from entering the lowermost separator by way of its particulate matter outlet, this is formed as a downwardly extended pipe, which is enclosed by a sleeve through which secondary air passes. The sleeve projects somewhat below the mouth of the pipe, and the issuing air causes an ejector action, which prevents gas from entering the pipe. The particulate matter return flow pipe from the upper cyclone is also extended downwards and terminates within the ejector.

Abstract: A burner head for combusting solid fuels such as straw, peat, chips, coal etc., comprising a charging opening (11) for the fuel and a discharge opening (15) for flue gases. According to the invention the burner head (1) is characterized in that it comprises two pipes (6,7) located concentrically to each other, where the gap (8) between the pipes is intended to communicate with a supply source for combustion air and communicates with the interior of the inner pipe (7) via apertures in the wall thereof. A plurality of apertures (12,13) are located a distance from the charging opening (11) to form a first combustion zone, and a plurality of apertures (14) are located a distance from said firstmentioned apertures (12,13) and closer to the discharge opening (15) to form a second combustion zone. In the first combustion zone the fuel is intended to be combusted incompletely. The gases produced thereby are intended to be combusted completely in the second combustion zone.

Abstract: A coal combustion apparatus capable of improving NO.sub.x reduction to a large extent is provided, which apparatus comprises a pulverized coal-feeding pipe (abbreviated to coal pipe) inserted into a burner throat on the lateral wall of a combustion furnace and for feeding the coal and air into the furnace; a means for feeding the coal and air into the coal pipe; a secondary air passageway formed between the coal pipe and a secondary air-feeding pipe provided on the outer peripheral side of the coal pipe; a ternary air passageway formed on the outer peripheral side of the secondary air-feeding pipe; a means for feeding air or an oxygen-containing gas into the secondary air passageway and that into the ternary air passageway; and a bluff body having a cross-section of a L-letter form provided at the tip end of the coal pipe.

Abstract: A two-stage process for staged combustion of crushed retorted particles, especially sulfur and nitrogen-bearing shale, provides maximum heat from combustible materials in shale while emissions of carbon monoxide and oxides of sulfur and nitrogen are minimized. In the first stage, combustion is maintained under fluidizing conditions with a substoichiometric amount of oxygen. Off-gases from the first stage are burned in a second-stage combustion zone utilizing an oxygen-containing gas stream controlled to limit emission of carbon monoxide in the flue gas. To minimize production of sulfur oxides, combustion temperature is concurrently maintained below a peak value of 1700.degree. F. by introducing inert gas or recycled decarbonized fines to the first-stage combustion zone to reduce temperature therein.

Abstract: A multi-annular swirl burner includes a plurality of overlapping tubular wall members which form a rich combustion zone and a lean combustion zone with a throat section therebetween. Annular passages are located between adjacent wall members, and vanes located therein input a tangential velocity to entering air. The tangential velocity of the swirling flows increases with increasing radius to produce centrifugal separating force on particulates moving from the rich combustion zone to the throat section. A collection system scavenges particulates from the throat section for disposal.

Abstract: This invention is directed to the suspension firing of a comminuted combustible material and the supporting structure for such suspension firing. The combustible material is introduced to a burner head which results in the combustible material expanding in a circular pattern. Inside of this circular pattern there is an outwardly directed flame to contact the combustible material. The result is an immediate ignition of the combustible material and the complete burning of the combustible material. There is also a refractory near the burner head. After the refractory has been heated to a desired temperature the outwardly directed flame can be discontinued and the heat energy from the refractory material is sufficient to assist in the immediate firing of the combustible material. A result of this is that an auxiliary fuel such as fuel oil or natural gas is not required, after the refractory has reached the desired temperature to sustain combustion of the combustible material.

Abstract: A fluidized bed combustion apparatus in which in the free-board above the bed at least one system of plates or baffles inclined with respect to the vertical is arranged so that at least one upwardly directed channel having internally at least one group of two opposed arrays of superimposed inclined plates is formed, which plates at least alternately extend obliquely downwardly from the outside to the inside and are closely connected with the outer boundary of the channel. Preferably all plates of each array extend obliquely downwardly at an angle with the vertical within 20.degree.-50.degree. from the outside to the inside from a vertical wall defining said channel whereas the plates of the one array are off-set over a distance "s" in the vertical direction with respect to the plates of the other array.

Abstract: A method is described for preparing hog fuel, other biomass, or peat for efficient burning and heat recovery in a water-wall boiler. The process requires drying the fuel to less that a 30% moisture content. The fuel is then pulverized to an upper particle size such that there are substantially no particles which will not burn in air suspension within the confines of the combustion zone and the boiler can meet emission requirements. Additionally, the pulverizing step is adjusted such that a fines portion of fuel is created of such size and in such amount that the fines portion readily self-ignites upon flame initiation. The fines provide sufficient ignition energy so that the entire flow of fuel burns without the necessity of the conventional fossil fuel support or pilot. The fuel is sized to burn in air suspension by injection into the boiler through a swirl stabilized-type burner.

Abstract: A power plant with a combustion chamber (8) with a fluidized bed (14) and a device for adjusting the bed height, comprising a storage container (21) for bed material, the storage container (21) being connected to the combustion chamber (8) by a first conduit (22) for feeding out bed compound from the combustion chamber (8) to the container (21) and a second conduit (23) for returning bed compound from the container (21) to the combustion chamber (8). The storage container (21) is connected, via a conduit (34) with a valve, to a space having lower pressure than the pressure in the combustion chamber (8). The return conduit (23) is connected, via a conduit (67) with a valve, to a pressure gas source (10) having higher pressure than the pressure in the combustion chamber (8). Transport of bed compound from the combustion chamber (8) is achieved by reducing the pressure in the storage container (21).

Abstract: A cake of biomass, preferably a peat cake, is dewatered by being pressed at a temperature above 90.degree. C., whereby the water in the cake is displaced by warmer water under successively increased pressure. An apparatus designed as a closed wash press is then used, in which the cake is subjected to dewatering, washing or displacement by warmer water and consequently heating as well as roller pressing.

Abstract: A process and burner for the partial combustion of a finely divided solid fuel, wherein coal and oxygen is supplied to a reactor space via a central coal passage and a plurality of inwardly inclined oxygen outlet passages supply oxygen. Each oxygen jet is surrounded by a shield of a moderate gas from an annular passage, preventing premature contact of free oxygen with reactor gas and the premature escape of solid fuel, broken-up by the oxygen jet from the break-up zone.

Abstract: An improved nozzle tip (10) for a burner on a pulverized coal-fired furnace for receiving a stream of pulverized coal and air discharging from the coal delivery pipe (50) of the burner and directing the pulverized fuel and air stream into the furnace, is comprised of a base body (20), a replaceable highly abrasion resistant insert (30), and a replaceable highly temperature resistant end cap (40) which is readily attachable by mechanical means (28, 48) to the base body with the abrasion resistant insert disposed therein. The insert defines a highly abrasion resistant flow conduit through the nozzle tip from the discharge end of the base body to the receiving end of the end cap through which the pulverized fuel and air stream passes from the burner into the furnace.

Abstract: A burner for the partial combustion of a finely divided solid fuel, comprising a central channel with a central outlet for free-oxygen containing gas, laterally disposed conduit means for finely divided solid fuel, the conduit means having outlet means whose major axis is positioned to intersect the axis of the central outlet and being asymmetrically arranged with respect to said central outlet. The invention further relates to a process for the partial combustion of a finely divided solid fuel, wherein one or more burners of the above type are applied.

Abstract: A method of operating a fluidized bed in which a bed of particulate combustible material and adsorbent material are disposed on a perforated plate. Air is introduced through said plate and into said bed to fluidize and promote the combustion of the combustible material, and a gaseous agent is injected into the bed to stabilize the surface hardness, sulfur-absorption properties and catalytic properties of said adsorbent material.

Abstract: There are the primary fuel nozzle for jetting the first coal in the fine powder form with an air ratio up to 1, and the secondary fuel nozzle for jetting the second coal in the fine powder form with an air ratio at least 1 from the outer circumferential portion of the primary fuel nozzle. Swirl means are located at the top of the secondary fuel nozzle for swirling the second coal.

Abstract: A method is disclosed for improving ignition time delay and carbon conversion efficiency in the combustion of coal water slurries wherein oxygen-enrichment of primary air is performed in the range of greater than 21% and up to 28%.

Abstract: A burner for the partial combustion of a finely divided solid fuel in a combustion zone, comprising a central channel for finely divided solid fuel, an annular channel for free-oxygen containing gas, substantially concentrically surrounding the central channel. The annular channel is provided with primary, inclined outlet means for directing high velocity free-oxygen containing gas into the outflowing solid fuel during operation and secondary outlet means around the primary outlet means for conveying shielding low velocity free-oxygen containing gas to the combustion zone.The invention further relates to a process for the partial combustion of a finely divided solid fuel, wherein one or more burners of the above type are applied.

Abstract: Flue gas from a coal-fired combustion to which a dry sulfur-binding additive is supplied, after cooling is subjected to filtration to remove additive ash therefrom. According to the invention, cooled additive ash is fed to at least a portion of the flue gas to reduce the temperature thereof approximately to the water dewpoint, thereby promoting the sulfur-binding reaction.

Abstract: The specification describes arrangements in which the attemperation or control of the temperature of a fluidized bed in a fluidized bed combustion unit effected by means of the mixture of a variable proportion of inert gas with fluidizing air fed to the bed may be supplemented with steam. Supplementation with steam being effected to a relatively minor extent during normal operation of the unit but being effected to a major extent when the temperature of the bed passes outside the range at which attemperation may be effected by use of recycled flue gas. The combustion unit is described in use within an arrangement including process plant in the form of a rotary drum dryer.

Abstract: A method of igniting a pulverized-coal pilot-burner flame for a pulverized-coal annular burner flame having an internal back flow region, with the ignition energy being introduced centrally into the interior of the back flow region of the pulverized-coal annular burner flame. To ignite the pilot-burner flame during the process of the initial ignition, at constant primary and secondary air flow and an air coefficient .lambda.--1.1 to 0.4, once or more a powder-laden air/powder mixture is supplied to the pilot-burner at a powder-laden air/powder weight ratio of 1.0 to 0.2. After ignition has been effected, a specified coal flow is continuously added to the pilot-burner flame at the fixed air coefficient .lambda.--1.1 to 0.4.

Abstract: Specimens of solid organic substances are decomposed by grinding the specimen to powder having particles of a size smaller than 75 microns, and then compressing the powder specimen. The compressed powder specimen is abraded by means of a scraper, and the abraded material metered out in predetermined amounts for incineration in an injector burner suitable for solids. In this manner, large quantities of specimen material which might contain elements that attack quartz glass can be incinerated without causing damage to the quartz glass burner. The apparatus for decomposing specimens of solid organic substances includes an injector burner that communicates with a powder processing and proportioning device through a flexible tube. The powder processing and proportioning device includes a specimen container for compressed powder, supported by a rotatable fixture to rotate the specimen container.

Abstract: A method is described for burning pulverized high ash coal in a furnace firebox and reducing ash fines which comprises(a) injecting a primary airstream containing a pulverized coal which is at least 7 wt % ash and a secondary airstream into the flame zone of a furnace firebox and combusting the coal to yield a flame of combustion, and(b) injecting a sufficient amount of oxygen into the flame zone via the secondary airstream such that the oxygen concentration of the combined primary and secondary airstreams is between 21 to about 28 vol %.In a preferred embodiment, the oxygen enrichment addition is proportioned between the primary and the secondary air streams.

Abstract: A direct fired system (10, 10') includes pulverizer means (14, 24), classifier means (12, 16, 18, 48, 76), burner means (16, 16') as well as a defined fluid flow path that serves to interconnect the pulverizer means (14, 24) and the classifier means (12, 26, 28, 48, 76) in fluid flow relation with the burner means (16, 16'). In accord with the mode of operation thereof, at the classifier means (12, 26, 28, 48, 76) a separation is had of the stream of the gaseous medium such that a portion of the gaseous medium is recirculated along with the oversize solid fuel particles back to the pulverizer means (14, 24) while the remainder of the gaseous medium is operative to convey the solid fuel particles that are of the desired size from the classifier means (12, 26, 28, 48, 76) to the burner means (16, 16') for burning, i.e., firing, in the latter.

Abstract: The object of the invention is to permit, for operation with coal by itself, easy adjustment of the flame length without varying the gas flow and with a relatively stable flame divergence. The burner according to the invention comprises a cylindrical tube (1) through which an air/fuel mixture is ejected into the flame, and inside which a coaxial cylindrical part (6) can move along the axis in order to permit adjustment of the output speed of the gas. Advantageously, this part (6) constitutes a means for injecting air and fuel-oil for mixed operation or operation with fuel-oil by itself.

Abstract: A hydro-pressurized fluidized bed combustor having an uptanding shell and an entry at its bottom for admission of feedstock. The feedstock passes through a conduit surrounded by a heat exchanger. Inside the shell an entry conduit is outwardly flared in the upward direction to furnish a controlled expansion entry feeding into the fluidized bed. The entry conduit has a plurality of tuyeres in its peripheral wall. An injector pump feeds the feedstock into the entry. A weir above the entry conduit keeps the height of the bed constant within the combustion during operation.

Abstract: A method and apparatus for reducing pollutant emissions, and in particular, for reducing NO.sub.x and particulate emissions, from a spreader-stoker-fired furnace and from a fluidized bed combustor. A combustible material of various sized particles is obtained and those smaller particles which would normally combust during the suspension phase of the spreader-stoker-fired furnace or fluidized bed combustor are separated from the larger particles. The larger particles of combustible material are then introduced into the spreader-stoker-fired furnace or fluidized bed combustor and combusted to produce heat.