Abstract: A flame-tube boiler is provided with a system of burners for the low-NO.sub.x combustion of heavy oil, with an air box (8) that communicates with the cooled flame tube (1) by way of a central primary-air channel (16) that surround an oil-burner lance (17) and by way of secondary-air feeds (18) that surround the primary-air channel. The flue-gas line (19) communicates with the flue-gas outlet (7) and accommodates a precipitator (20), which has a solids outlet that communicates with a ring of nozzle pipes (24) inside the burner and opening into the flame tube.

Abstract: A process for preparing a feed gas, for a thermolytic detoxification reactor or other processing units, utilizing an autoclave is described. A container of liquid waste is placed in an inerted and atmospherically sealed enclosure and hot gaseous effluent from the reactor is introduced to the interior of the enclosure outside the container to heat the liquid waste. The hot gaseous effluent is recirculated from the enclosure to the interior of the container to mix with the gaseous contents thereof. Gas is conducted from the interior of the container to the reactor as feed gas. The autoclave can also be fed by a pumped liquid waste stream.

Abstract: In order to rationalize the operation of foundries and to avoid environmental stresses, it is endeavored so to rework used molding sand accruing as black sand and to free it from binder residue, so that this sand can be used without restriction like new sand. To achieve this aim through thermo-mechanical regeneration the black sand is heated in predetermined, relative low height layer in a fluidized bed furnace to a temperature exceeding 500.degree. C., preferably 750.degree. C. Through the swirling motions of the heated black sand, preferably supported through strong vibrations of the supporting base, the thermal destruction of the enveloping binder particles and a mechanical liberation of the sand grains form their enveloping binder remains is achieved. By means of a forced throughout (e.g.

Abstract: An apparatus for treating a combustion exhaust gas is here provided which comprises a fire furnace, a denitrating reactor for denitrating the combustion exhaust gas discharged from the fire furnace, a dust collector for collecting solids in the exhaust gas passed through the reactor, and a transport pipe for circulating the solids collected by the dust collector through the fire furnace, the apparatus being characterized in that the transport pipe is provided with an arsenic removal means for removing arsenic from the solids. The arsenic removal means may be a heating device or a washing device. The dust collector may be provided with a means for discarding the solids having a particle diameter of 10 .mu.m or less.

Abstract: A steam generator and a method of burning fuels therein. A combustion chamber of gas-tight pipe walls has a fluidized bed. Above the bed is a free space with an incrementally lower solids density that accommodates heat-convection surfaces. Coarse-particle precipitators communicate with the top of the combustion chamber with their solids-extraction outlet communicating with the fluidized bed through a feedback system. The combustion chamber, its heat-convection surfaces, the coarse-particle precipitators, and the feedback system are surrounded by pressurized vessel. The fuel is burned in the fluidized bed under pressure. Densities of 0.5 to 5 kg of solids per kg of flue gas are maintained in the free space (4) above the bed by means of fluidizing rates of 1 to 5 m/sec. The temperature of and load on the fluidized bed are regulated by the amount of solids returned to the bed.

Abstract: An oven (20) includes an oven enclosure (24) having a conveyor (40) mounted therein for transporting food products through the oven. A plurality of ribbon burners (100) are mounted within the oven interior (32) adjacent the path of the conveyor to heat the interior of the oven. Heated gases generated by operation of the ribbon burners are received through inlet plenums (140) under operation of a circulation fan (146) and are discharged through discharge tubes (154) extending adjacent portions of the conveyor (40) remote from the locations of the ribbon burners (100). Exhaust gases are removed from the oven interior through discharge ports (180) by exhaust blower assemblies (184) which are operated to remove exhaust gases from the oven interior at a rate proportional to the flow rate of combustion air and gaseous fuel into the ribbon burners.

Abstract: A method of purifying flue gas from the firing equipment of a combustion unit, especially fuel gas from fitting equipment to which low-ash flue is supplied, or from a grating firing having a high degree of ash removal, with the flue gas containing noxious compounds. A finely divided or pulverous basic additive is used on which the noxious compounds produced during firing are adsorbed. Flue dust, especially flue dust/additive mixture, that is carried along in the flue gas is separated from the latter, with at least a portion of the separated-off flue dust being hydrated and sifted, whereby subsequently at least a portion of the dry, hydrated flue dust is returned to the flue gas purification process. Non-pulverized flue dust is homogenously mixed with finely sprayed water to effect the hydration. The return of flue dust to the flue gas purification process is undertaken by returning at least a portion of dry, thus-hydrated flue dust to the firing equipment of the combustion unit.

Abstract: A power production system is disclosed. The system includes a firebox, and fluid-containing heat transfer coils at the firebox sides. The heated fluid is conducted to a transducer for converting that heat into mechanical work. In the illustrated embodiment, the transducer includes a piston and cylinder arrangement. A converter is disposed adjacent the firebox to receive heat and the gaseous products of combustion from the firebox. The converter chemically converts the gaseous products of combustion into less objectionable materials.

Abstract: A method for reducing the NO.sub.x content of effluent gas in a coal-dust-fired combustion system comprising establishing at least two vertically adjacent burner planes, in which the burner flame cores are fed with primary air in the core zones in a substoichiometric ratio to the coal dust feed stream and are additionally fed with secondary air comprising recycled flue gas in optional combination with preheated fresh air, and in which the burner mantle zones are fed with tertiary air comprising recycle flue gas and optional fresh air, so that, overall, a substantially stoichiometric combustion air ratio is established in the region of the lower burner plane and, overall, a highly substoichiometric combustion air ratio is established in the region of the upper burner plane. The apparatus employed is an economical primary measure requiring little space and minimal loss of energy, and is easily retrofitted in existing plants.

Abstract: The invention relates to a method of cleaning the heat transmission surfaces of a steam boiler or the like. In the method the deposits which are formed on the heat transmission sufaces of the superheater of the boiler and the other heat transmission surfaces thereof during the operation and which hamper the heat transmission are removed by directing a cleaning jet of medium to said surfaces through sweepers. In order to provide a reliable, simple and energy saving cleaning method, the flue gases of the boiler are used as a medium. The flue gases can be taken from a gas flue positioned after an electric filter.

Abstract: The subject invention relates to an improved method and apparatus to control the rate of heat release (ROHR) from a reaction zone confined within a chamber, air and fuel having been introduced into said reaction zone to achieve combustion, plural sensors being utilized one sensor adapted to sense ROHR, another to generate a target value for a desired ROHR within a comparator, still another sensor to determine heat generation and transmit it to the comparator, a control means for controlling ROHR of heat generation and connecting said comparator with said control means to achieve coincidence between a target value and said sensed value.

Abstract: A high temperature combustion process for an organic fuel containing sulfur n which the nitrogen of air is replaced by carbon dioxide for combination with oxygen with the ratio of CO.sub.2 /O.sub.2 being controlled to generate combustion temperatures above 2000 K. for a gas-gas reaction with SO.sub.2 and an alkali metal compound to produce a sulfate and in which a portion of the carbon-dioxide rich gas is recycled for mixing with oxygen and/or for injection as a cooling gas upstream from heating exchangers to limit fouling of the exchangers, with the remaining carbon-dioxide rich gas being available as a source of CO.sub.2 for oil recovery and other purposes.

Abstract: In a process for reheating flue gases originating in furnaces operated with fossils fuels, the flue gases, before being introduced into the chimney, receive heat energy that has been generated in a fluidized bed furnace. Sulfur binding agents are added to the fluidized bed furnace and the flue gases of the this furnace are added to the cleaned flue gases after removal of the suspended dust.

Abstract: A method and apparatus for reducing the NO.sub.x content of hot stack (exhaust) gas produced by a furnace burning a fossil fuel, comprising recycling part of said NO.sub.x -containing stack gas, in admixture with cold fresh air, back into the combustion chamber of the furnace.

Abstract: A butterfly-type step subassembly includes a substantially planar valve disc member having a peripheral groove formed in opposite surfaces thereof. Projecting inwardly from the internal walls of the subassembly housing are two non-coplanar, generally semicircular valve seat members having passageway(s) in them communicating outside the housing with a source of purified gas(es). The passageways terminate interiorly in apertures in respective recesses in the seat members positioned to be brought into communication with said grooves when said valve disc member is in substantial contact with said seat members. Means are provided to supply said purified gas(es) to said passageways in response to the movement of said planar disc member to the nominally closed position so that said gas(es) flow into the contact region between the disc and seat members under sufficient pressure to prevent said effluent from flowing through said valve when nominally closed.

Abstract: Temperature of exhaust gases from a fluidized-bed boiler is lowered by means of heat exchange and dust entrained in the exhaust gases is efficiently collected by a dust collector. Part of the gases discharged from the dust collector are mixed with heated combustion air and are charged into a fluidized bed. Therefore, problems caused by dust entrained in the exhaust gases to be mixed with the combustion air as well as the cold corrosion problem can be substantially solved so that the technique for reducing the NO.sub.x contents in the exhaust gases from the fluidized-bed boiler is satisfactorily established.

Abstract: A furnace arrangement utilizes a single vertically disposed shaft furnace incorporating the features of pellet drying and hardening, oxidizing heat-up, reducing roast and gas separation. The upper portion of the furnace dries and hardens "green" pellets while at the same time subjecting them to an oxidizing atmosphere and temperature increase. A stack of the pellets slowly moves downwardly through a transistion zone to a reducing atmosphere in a lower portion of the furnace. A heated reducing gas circulates through this lower portion and out of the furnace through a recovery system of the furnace arrangement. After the sublimate carried by the reducing gas is removed, the reducing gas is supplemented and returned to the lower portion of the furnace to again produce a reducing atmosphere. A smaller branch of cooled reducing gas enters the lower portion of the furnace adjacent the bottom to cool the pellet residue immediately prior to removal from the furnace.

Abstract: A compact incinerator for biomass has an upright combustion chamber coaxially surrounded by a passage through which the biomass is fed from a separator in which the primary air is separated from the biomass, to the combustion chamber. An afterburner chamber surrounds this shaft so that flue gases from the combustion chamber can pass through the shaft and be filtered by the biomass while heating the biomass before afterburning is effected in the afterburner chamber. The primary air from the separator is preheated in a preheater in indirect heating exchange by the flue gas in the same coaxial apparatus which also includes, coaxially with the combustion chamber, a flue gas/solids separator for removing solids from the flue gas before it enters the preheater.

Abstract: A heat exchanger-combustion chamber construction includes a combustion chamber and a heat exchanger chamber. Disposed in the heat exchanger chamber is an array of inlet tubes, the outlets of which discharge into the combustion chamber. Combustion products discharged from the combustion chamber are flowed over the inlet tubes in heat exchange relation. An array of aspirator sleeves of larger inner dimension than the outer dimension of the inlet tubes is secured to divider structure between the heat exchanger chamber and the combustion chamber, each aspirator sleeve receiving the outlet end of a heat exchanger tube while permitting longitudinal movement of the heat exchanger tube within the sleeve (due to thermal expansion, for example).

Abstract: The wet method of combusting organic material dispersed in a liquid comprising waste liquor from wood pulping processes in which the organic material is oxidized by contact with air or other oxygenating gases at a temperature ranging between 180.degree. C. and 340.degree. C. and a correspondingly superatmospheric pressure.

Abstract: A garbage to hydrocarbon fuel conversion system is provided which generates electricity and hydrocarbon gases from combustible garbage. The garbage is pulverized and then burned in a destructive distillation process. The heat produced is used to generate electrical power. Dust precipitated by an electrostatic cottrell precipitator is mixed with light oil and burned in an oil burner. The heat obtained is used to maintain the destructive distillation. The gases which rise to the top of the precipitator are passed through a hydroxide solution which leaves a layer of tar and oil floating on top of the solution and a volume of hydrocarbon gases on top of this layer.

Abstract: A process and a means is described for burning solid fuels, preferably coal, in pulverized form, which are mixed with a carrier liquid, such as water and/or oil or the like, to thereby form an emulsion, and for this purpose the fuel emulsion is injected through a substantially annular entrance port into a combustion chamber so that an approximately hollow cone-shaped flow configuration is produced. Within this flow configuration, a low pressure is built up immediately behind the entrance port for the fuel emulsion opening into the combustion chamber, so that a portion of hot combustion gases and a remainder of unburnt fuel particles are recirculated to the entrance port. Furthermore, gas entrance ports are provided in the end wall of the combustion chamber, through which the gas or air flows the path of flow of which extends concentrically and spirally towards the axis of the entrance port for the fuel emulsion opening into the combustion chamber.

Abstract: A city refuse incinerator provided with stoker type firing equipment for combustion of city refuse has gas injectors installed low on the inside of a furnace body to inject low temperature inert combustion exhaust gas, purified in a dust collector, so that a gas curtain is formed on the inner surface of side walls of the furnace by the low temperature inert gas, thus preventing the formation of clinkers.

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 steam generating unit using gas recirculation (28) for steam temperature control, where the recirculated gases are introduced (38) into the furnace (12) through the bottom opening (34) through which the ash is discharged. Dampers (40) are positioned in the gas recirculation duct (28) for controlling flow therethrough.

Abstract: A shell boiler is disclosed having apparatus for feeding solid fuel to a furnace grate, contained within a furnace tube of the boiler, downwardly through the steam and/or water space of the boiler. The apparatus for feeding solid fuel to the furnace grate comprises a device for classifying and separating fine particles of fuel, having a particle size below a predetermined size, from the remainder of the fuel and feeding the fine particles into the furnace tube at a different location to that at which the remainder of the fuel is introduced into the furnace tube. The fine particles may be fed through a grit arrestor and fed into the furnace tube along with the grit separated by the grit arrestor.

Abstract: A method of drying wet coal fines smaller than 28 mesh in size employs both a vibrating fluidized bed type dryer and a coal fired burner for supplying hot drying gases to the dryer. A regenerative separator is interposed between the coal fired burner and the fluidized bed type dryer to satisfactorily remove particle matter from the gases without unacceptable pressure losses. Hot gases exhausted from the fluidized bed type dryer are also cleansed to remove particulate coal particles which are used as fuel for the coal fired burner.

Abstract: An apparatus and method accomplishes the burning of biomass fuel materials with up to 80 percent efficiency. The inventive method and apparatus utilize a catalytic converter in communication with a combustion chamber to combust more completely combustion product gases to eliminate hydrocarbon pollutants and produce carbon dioxide gas. The catalytic converter is included within a passageway originating from and terminating in the combustion chamber so that the carbon dioxide gas is directed into the combustion chamber to control the rate of combustion therein. A heat exchanger in communication with the combustion chamber converts for use the heat carried by the carbon dioxide gas.

Abstract: A waste material treatment furnace includes a furnace chamber having an interior surface formed by a flexible sheet of an insulating fabric to minimize heat-up and cool-down time and to facilitate interior surface repair. The treatment furnace additionally includes an exhaust gas treatment facility for neutralizing and/or removing undesirable elements from an exhaust gas stream. The treatment facility includes a chamber having inlet and outlet openings, a conduit therebetween defined by wall members permeable to the passage of exhaust gas therethrough. A supply of a selected reactive material is provided in a compartment formed about the periphery of the permeable wall members, and means are provided to move the exhaust gas from within the conduit through the permeable wall members thereof into the selected reactive material within the compartment.

Abstract: Improved method and apparatus are disclosed for regenerating wet spent carbon containing volatile impurities wherein the wet spent carbon is dried in a drying zone utilizing incinerated reactivation zone gaseous effluent. The improvement of the invention provides that the portion of reactivation zone gaseous effluent used to dry the wet spent carbon in the drying zone is continuously recycled to the reactivation zone for incineration to remove any volatile impurities which may have been removed from the wet spent carbon during drying. The balance of the reactivation zone gaseous effluent may be discharged into the atmosphere without further incineration.

Abstract: Apparatus and method for burning green wood chips in which the hot combustion gases generated by the burning of the chips in a furnace are passed through chips in a storage silo from which the chips are subsequently fed to the furnace. A column of chips of substantial height is maintained in a top vented silo. Chips are fed from the lower portion of the column to the furnace and usually mixed with other fuel such as particulate coal or coal dust, and the hot combustion gases from this combustion are fed into the silo at a location substantially below the top of the column of chips so that the gases permeate and pass upwardly through the column of chips to dry them. The chips also act as a filter to remove environmental contaminants from the gases.

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: The present invention relates to a method and apparatus for the thermal treatment of combustible materials wherein the materials to be treated are introduced in a cylindrical enclosure of horizontal axis. A stream of hot gases flowing around the horizontal axis places the particles of materials in suspension. A fraction of the hot gases is recycled outside the enclosure with a view to being re-introduced therein. The apparatus is particularly suitable for treating fine vegetable materials, such as chopped straw.

Abstract: A hot combustion gas recycle apparatus for a starved-air combustor for mixing hot combustion gas with significant amounts of air to heat the air. The heated air is injected as underfire air into the first combustion zone of the combustion chamber to heat and to dry the fuel in the fuel bed as an aid to combustion efficiency. The recycle device includes a temperature control system for controlling the ratio of gas to air and a control valve to completely shut off the flow of combustion gas to the recycle device if the gas and air mixture exceeds a preset maximum.

Abstract: A burner throat, secured between a producer and a burner, the burner throat including a superheating means comprising a return gas line drawing hot combusted gases from the burner to the burner throat through an annular chamber surrounding the inlet portion of the burner throat, the burner throat also including an out-of-line fan discharging an air stream vertically in inlet portion of the burner throat to create a suction chamber thereat; the burner is multichambered and includes secondary air inlet means for providing excess oxygen for producer gas combustion in an excess of oxygen, a portion of the burner is enclosed in a tunnel having an open end and a fluid flow, the fluid flow transmits heat from the burner through a first damper in the tunnel, and into a large fan enclosed within a fan room; the fan room has a supplemental heat source and second dampers; the fan has a plenum at its discharge side for receiving a heated discharge fluid flow from the fan to distribute to grain bins; the plenum includes a

Abstract: A continuous process for the combustion of solid fuels in the presence of an aqueous liquid phase under conditions such that oxides of nitrogen are not formed and oxides of sulfur and particles of ash are effectively prevented from contaminating the gaseous products released to the atmosphere. Fuel is charged as a slurry in alkaline aqueous solution and contacted with combustion air so that the catalytic properties of both water and alkali operate to permit rapid and complete combustion at comparatively low temperatures. Temperatures in the adiabatic reactor are, however, permitted to exceed the critical temperature of the liquid phase. Under the conditions of the process, formation of nitrogen oxides is negligible, sulfur in the fuel goes to sulfur trioxide which dissolves completely in the alkaline liquid phase which also retains particles of ash and unburned fuel. The resulting flue gas is essentially free from objectionable pollutants.

Abstract: An apparatus for removing particulate matter from a flue gas stream exiting a vapor generator and recirculating said gas back to the generator. The apparatus includes a back face, a bottom face and a recirculation duct. The recirculation duct is located in front of the apparatus, thereby increasing the access area in the vicinity of the generator burners and facilitating maintenance of said burners. The back face, bottom face and recirculation duct envelope ash hoppers and other internal components of the apparatus.

Abstract: In thermal regeneration incineration apparatus having a main combustion chamber in communication with at least one heat-exchange section to which inlet and outlet ducts are connected, each duct having an associated valve, purified effluent from the output of the apparatus is fed back to blanket at least one side of one or both of the valves. This helps to prevent unpurified effluent applied to the input of the apparatus from leaking through the valves when nominally closed and thereby avoiding passage through the main combustion chamber.

Abstract: A system for disposing of sewage sludge by treating the sludge in apparatus which processes the sludge through relatively inert gas drying and grinding stages and utilized as much of the dried and ground sludge as is needed to produce heat for maintaining the drying process in the system once the system has become substantially self sufficient on use of the sludge as the drying heat source. The remaining excess sludge is then in a form either granular or fine suitable for direct sale.

Abstract: A method of curing a solvent based coating on a strip comprising passing the strip through oven zones, circulating hot gases in the zones to vaporize solvents and entrain them in such gases and cure the coatings, the solvents being released in high volume one zone, and in low volume in another zone, incinerating some of the gases in the zones to oxidize solvent vapors and returning them to the zones, extracting some solvent-rich gases without incineration from the high release zone and distributing them to other zones, incinerating the solvent-rich gases as they are introduced into the other zones to oxidize solvent vapors and discharge high temperature combustion gases in the zones supplying some heat for the zones and reducing solvent vapors, extracting some of the gases from some zones and introducing them into the high solvent release zone to partially replace the gases transferred, the balance being made up by upstream migration of zone gases within said oven, and exhausting some gases to atmosphere.

Abstract: A method and apparatus for heat treating metals to remove contaminants. Contaminated scrap metal is fed into one end of a rotating inclined retort. Heat is applied to the retort as the scrap metal is conveyed therein to remove the contaminant, and the processed metal is discharged from the opposite end of the retort. Combustible waste gases generated through the processing are fed to an afterburner where the combustible gases are burned and are discharged from the afterburner into a stack. A portion of the hot combusted gases are returned from the stack to the discharge end of the retort to thereby minimize oxidation of the scrap metal being treated as well as conserving fuel.

Abstract: The specification discloses and describes a method and means of operating an incinerator whereby the concentration of evaporated solvent or other combustible materials delivered to an incinerator is controlled as a reflection of the temperature of the gas stream made up of products of combustion exhausted from the incinerator. By maintaining the fuel input to the incinerator constant and also maintaining the temperature of the stream of gases entering the incinerator constant, the variation of the temperature of the stream of products of combustion emitted from the incinerator with respect to a standard value reflects the variation in the concentration of evaporated solvents or other combustibles in the stream of gases supplied to the incinerator.

Abstract: This invention relates to a burning furnace of hot gas recirculation type for minimizing fuel cost. The furnace includes a cyclone which receives dust-containing exhaust gases. One or more secondary air-introducing nozzles are provided for the cyclone at top of or in close proximity to the upper end of the cyclone leading concentrically to a flue gas passage such as funnel. Upon introducing secondary air under pressure into the cyclone, a downwardly directing swirling air flow is formed therein for the separation of heavier dust together with part of the fed exhaust gases. The thus separated air-hot gas mixture including heavier dust particles is returned to initial stage of the furnace for the recirculation through the furnace.

Abstract: An arrangement for inhibiting low temperature gas-side corrosion of an out of service steam generator and its heat exchange and gas clean-up adjuncts. The arrangement provides for circulating pressurized heated air through the steam generator and its adjuncts, controlling the pressurization of the air to maintain positive gas-side pressure, controlling the heating of the air to maintain gas-side surfaces above the dew point, and returning the air which has passed through the steam generator and its adjuncts to the forced draft fan to be repressurized, reheated and reintroduced into the steam generator.

Abstract: A method of heat treating a workpiece, and an oven for carrying out the method in which, the gaseous atmosphere within each zone is continuously recirculated by recirculating fan and duct systems within each zone, and directed onto the workpiece, thereby losing heat to the workpiece, and coating thereon. A substantial proportion of the oven atmosphere containing solvent vapors is continuously passed through individual zone incinerators located within each of the oven zones, thereby oxidizing the solvent vapor content of such portion. The incinerated proportion of gases is then re-mixed with the untreated gaseous atmosphere prior to entry to the recirculating fan and duct system thereby re-heating the gaseous atmosphere to a controlled elevated temperature.

Abstract: A heat reclaimer for use with a gas clothes dryer of the type including a rotary drum. The dryer includes a housing in the upper portion of which is a gas burner chamber. The heat generated in the gas burner is moved downwardly through the rotary drum by a blower mounted in the lower portion of the housing then out a discharge stack. The heat reclaimer includes a downwardly open conduit located centrally in the stack and recirculating a portion of the air from the stack back into the gas burner chamber, on the opposite side of the burner and on the downstream side of the heated air passage from the burner to the clothes dryer. An inverted deflector cone is mounted at the lower end of the conduit. The discharge stack has an enlarged diameter at the portion of the stack which contains the conduit. The junction of the conduit and the gas burner chamber is in the form of a long narrow slot to better mix the recirculating air with the air in the gas burner chamber.

Abstract: A low polluting solid waste burner utilizes a first combustion chamber in which the solid waste is partially oxidized under a positive pressure with the partially oxided gaseous combustion products passing out into a first conduit where the gas is recycled for dual burning back into the first combustion chamber. A conduit is also provided between the ash compartment and the combustion chamber to completely oxidize ash compartment gases with complete combustion product gases being conducted away to a spray tower or water curtain by the positive pressure in the combustion chamber produced by the combustion air blower. A second combustion chamber may be used to further oxidize the gaseous combustion products.

Abstract: Gas-fluidized ground coal, and coal dust slurried with fuel oil, are supplied to a reverse flow cyclone combustor which provides the functions of combustion and particulate removal. Coal dust borne by the fluidizing gas is passed through a cyclone scrubber utilizing fuel oil, and the resulting slurry is introduced into the combustor adjacent the inner surface of the combustor wall. Only the finest coal dust is employed in the slurry, to minimize oil consumption. Separative performance of the combustor is enhanced by introducing combustion air centrally adjacent the combustor outlet and gas-borne ground coal directly onto the cyclone walls.

Abstract: An entirely dry, solid waste disposal system is provided which incinerates waste in a manner to minimize pollution and to utilize the heat energy which is a by-product of the incineration. The waste material is shredded and then dried by mixing it with heated ambient air in an elongated dryer. A helix propels the waste through the dryer and into a combustion chamber together with the hot ambient air which was employed to dry the waste material. The hot gases resulting from incinerating the wastes are directed to a boiler wherein steam is generated. The steam thus produced is used to generate electricity and additionally may be utilized as a source of heat for heating or drying. The hot gases from the combustion chamber and the boiler are fed to the dryer for waste drying purposes. Exhaust gases from the dryer are fed to a scrubber to remove any remaining pollutants prior to being exhausted into the atmosphere.