Abstract: The present invention includes a gasifier for gasifying fuels having a container with a top, sidewalls and a bottom for facilitating the gasifying process. One or more open vertical shafts extend downward inside the container for allowing a downdraft or updraft of air and fuel for the gasifying process. A rotating bed is preferably included inside the container and below the one or more shafts for receiving the fuel. The bed rotates essentially perpendicular to the shaft to facilitate even heating and gasifying of the fuel. The bed is further movable relative to the vertical shaft in order to increase or decrease the volume of fuel flow to the fuel.

Abstract: A plasma assisted gasification system with an indirect vacuum system for drawing syngas through a reactor vessel is disclosed. In particular, the plasma assisted gasification system is configured to draw syngas through the combustion reaction zone, the syngas collection chamber, the syngas heater and the syngas outlet in the reactor vessel. The plasma assisted gasification system may include a reactor vessel with distinct reaction zones that facilitate greater control and a more efficient system. The system may include a sealing system for a continuous feed system of a gasifier enabling an inlet opening of a feedstock system to remain open yet seal the reactor without a mechanical system. The system may include a syngas heater channeling syngas collected downstream of the carbon layer support and to the pyrolysis reaction zone. The system may further include an agitator drive assembly that prevents formation of burn channels with in the fuel.

Abstract: A gasifier includes a combustion zone where a gas is introduced and fuel is combusted and at least one sensor for measuring a predetermined condition in the gasifier. A grate subsystem contains the fuel and includes at least one grinding mechanism. A controller is responsive to the at least one sensor and controls the grinding mechanism by activating the grinding mechanism if the predetermined condition exists to reduce the collection of non-fuel products on the grate subsystem.

Abstract: A controlled zone gasification reactor with an agitator drive assembly for a plasma assisted gasification reaction system is disclosed for converting fuel, such as, but not limited to, biomass, to syngas to replace petroleum based fuels used in power generation. The agitator drive assembly that prevents formation of burn channels with in the fuel. The agitator drive assembly may include a syngas separation chamber configured to produce clean syngas, thereby requiring less filtering. The syngas separation chamber may feed syngas downstream to a syngas heater in a pyrolysis reaction zone in the reactor vessel.

Abstract: Embodiments include a gasification process where the carbon content of the residue from gasification of agricultural waste products and the fly ash content of the gaseous exhaust is controlled by regulated inflow of gasification-supporting air in a plurality of flow stream at different velocities to enhance fluidization of particulate feed in a bed being raked by a rotating sweep arm inducing radially outward movement of gasification residue into a collecting zone from which the residue enters a discharge duct. The particulate feed is dropped at a location in the gasification chamber above the bed in alignment with the inflow stream of maximum velocity.

Abstract: A solid fuel gasifier includes first wall structure (12) defining a gasification chamber (14) and means (50, 52) to collect particulate solid residue from gasification in the gasification chamber. Second wall structure (16) defines a gas combustion chamber (17) and means (19) is arranged for admitting a flow of hot gases from the gasification chamber to the gas combustion chamber as combustion takes place. Also provided is means (178, 170) to conduct hot gases from the gasification chamber and/or gas combustion chamber into thermal contact with said collected particulate solid residue, for facilitating post-combustion and/or post-reduction of the solid residue. Also disclosed are an agitator bed (52, 182) for fine particulate material, and a method of gasification of solid fuel.

Abstract: An apparatus and method for starved air gasification of solid organic materials, including biomass and other wastes, to convert the chemical energy stored in such materials to thermal energy or gaseous products that may be used in biochemical and/or chemical synthesis. Specifically, the system utilizes a gasifier having a “moving bed of ash” hearth wherein the feedstock is partially oxidized at a low temperature (less than 1500 degrees F.) in a square or rectangular chamber having a vaulted, tapered or flat roof. Combustion gases from the gasifier are held at temperature using a recovery and regeneration chamber, and then undergo secondary oxidation in an oxidizer. The high temperature gases produced by the system can be utilized to advantage, for example, as the thermal energy source for a conventional heat recovery device such as a heat exchanger, steam generator, hot oil or air heater, or steam boiler.

Abstract: Apparatus and method for gasification of waste are disclosed. Waste material is fed to the top of a first combustion chamber, and a burning, rotating annular column of waste is supported in the combustion chamber. Combustion air is introduced to the first combustion chamber at or below the support for the burning annular column of waste so that the combustion air moves upwardly through the burning column. Combustion gases are withdrawn from the top portion of the first combustion chamber. Particulates are removed and recirculated to the first combustion chamber. The combustion gases are then fed to the top portion of a second combustion chamber. Secondary combustion air and optional fuel are fed to the second combustion chamber to complete the gasification process. A relatively clean producer gas is withdrawn from the bottom portion of the secondary combustion chamber.

Abstract: A grate assembly for a coal gasifier of a moving-bed or fixed-bed type is provided for crushing agglomerates of solid material such as clinkers, tailoring the radial distribution of reactant gases entering the gasification reaction zone, and control of the radial distribution of downwardly moving solid velocities in the gasification and combustion zone. The clinker crushing is provided by pinching clinkers between vertically oriented stationary bars and angled bars supported on the upper surface of a rotating conical grate. The distribution of the reactant gases is provided by the selective positioning of horizontally oriented passageways extending through the grate. The radial distribution of the solids is provided by mounting a vertically and generally radially extending scoop mechanism on the upper surface of the grate near the apex thereof.

Abstract: A vertical, countercurrent, updraft reactor is provided which can be advantageously used to produce synthesis gas by the partial oxidation of a solid fuel, especially a wood particle fuel. The reactor has a substantially cylindrical, vertical shell. The reactor has a fuel inlet opening in the upper portion of the reactor and an ash outlet opening in the lower portion of the reactor. Also in the lower portion of the reactor is a synthesis gas outlet opening. A heating zone is created within the reactor by internal heating zone walls which terminate at a lower-most edge. A grate is located below the heating zone. The outer perimeter of the grate and the lower-most edge of the heating zone walls form an annular slit which allows ash to gravitate out of the heating zone and into the lower-most portion of the reactor. The grate is reciprocal so that the annular slit can be periodically narrowed and widened.

Abstract: An apparatus for fixed-bed coal gasification is described in which coal such as caking coal is continuously pyrolyzed with clump formation inhibited, by combining the coal with a combustible gas and an oxidant, and then continually feeding the pyrolyzed coal under pressure and elevated temperature into the gasification region of a pressure vessel. The materials in the pressure vessel are allowed to react with the gasifying agents in order to allow the carbon contents of the pyrolyzed coal to be completely oxidized.The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel.

Abstract: In a rotary-grate gas producer operated under a pressure from 10 to 100 bars, the fuel constitutes a fixed bed, which slow descends. The mixture of gasifying agents contains water vapor and oxygen is supplied to the fixed bed through a rotary grate and through an ash layer, which is disposed on the rotary grate. In order to ensure that the ash will have a particle size in a desired range, a first pressure (p1) is measured below the rotary grate and a second pressure (p2) is measured approximately at the top of the ash layer. The pressure difference (p1-p2) is compared with a setpoint, which is associated with the current ratio of water vapor to oxygen in the mixture of gasifying agent. Said ratio is increased when the pressure difference is insufficient and the ratio is decreased if the pressure difference is excessive.

Abstract: A method and an apparatus for producing generator gas and activated carbon from solid fuels. A first gasification stage is supplied with fuel by an underfeed charging system and preheated air, the air and fuel being supplied in the same direction. In a second gasification stage and accompanied by the supply of secondary air, an intermediate gasification takes place. Finally, in a third gasification stage, the gas is reacted with glowing coke or charcoal, and the heat of the exiting gas is used for heating the air. The fuel centrally entering the first gasification stage is led from the inside to the outside and then upwards. Part of the entering fuel is precombusted in a precombustion chamber linked with the supply of the preheated air for reducing the oxygen content of the preheated air. In the intermediate gasification stage, the gas with the admixed air is passed through a Venturi nozzle or tube with a diffuser.

Abstract: A gasifier system for obtaining relatively clean combustible gaseous products from solid fuel materials, such as processed sewage sludge, comprises a gasifier reactor which communicates a raw, combustible gas to a cyclone separator, a gas scrubbing device and a gas cooling and drying device. Gas which exits the system is relatively clean and may be used in a prime mover for the production of energy.The gasifier reactor of the present invention is a down-draft fixed bed gasifier. The gasifier is constructed of several interconnected modular units. Moreover, the gasifier is constructed so as to efficiently gasify fuel materials while maintaining excellent horizontal temperature control.

Abstract: The fuel constitutes a fixed bed in the reactor, which is provided in its lower portion with a rotating grate, which is adapted to be speed-controlled. The gasifying agents consisting of oxygen, steam and/or carbon dioxide are introduced through the rotating grate into the fixed bed. Under the action of the rotating grate the incombustible mineral constituents are delivered as solid ash to a lock chamber container. The speed of the rotating grate is controlled in dependence on the temperature in the lock chamber container. The speed will be decreased when the temperature in the lock chamber container exceeds a desired value, and increased when the temperature is too low. The desired temperature in the lock chamber container is taken into account as a range, which varies with time. The speed can be controlled by hand or can be automatically controlled with the aid of a computer. The rate at which oxygen as a gasifying agent is supplied to the reactor is also taken into account in the speed control.

Abstract: A fixed bed gasifier for wood or other solid fuel has an air supply grate or grid spanning its interior horizontally substantially above the floor of the gasifier reactor vessel. The air supply tubes forming the grid are widely spaced apart to offer minimal resistance to the downward movement of ash in the reactor vessel. The ends of the grid tubes are supported by stuffing boxes on the side wall of the reactor vessel. An ash removal auger communicates with an ash pit at the bottom of the gasifier reactor vessel and a separately powered rotating ash plow operates in the ash pit above the ash removal auger and below the level of the air supply grate or grid.

Abstract: An upright, cylindrical down draft gasifier has a rotatable grate which supports a quantity of pyrolyzing biomass materials. As the grate is turned, charcoal particles thus formed fall through apertures in the grate and into a collection chamber. Simultaneously a high quality combustible gas is continuously withdrawn. A number of stationary, horizontal rods are disposed above the grate to retard and mix the reactant in the column and force a portion of the charcoal particles through the apertures. Additionally, the rods, in conjunction with the grate, present a shearing action on larger charcoal particles until the latter are crumbled and consequently fall through the grate. As the speed of the rotable grate is increased, the quantity of combustible gas and high quality charcoal is enhanced such that the heating value of the final product is also greatly increased.

Abstract: A process for continuously gasifying wood, wood chips, wood charcoal, or other low-ash biomass material in a mechanically-ashed gasifier using a fixed bed gasification system to obtain a gaseous product relatively rich in carbon monoxide and hydrogen. Product gas comprising carbon monoxide, hydrogen, and carbon dioxide, together with methane and other diluents, is withdrawn from the gasification chamber. Sufficient noncombustible, particulate, refractory material is fed to the gasifier to provide an adequately deep layer of noncombustible solids on a moveable grate which supports the fuel bed, the object being to prevent damage to the grate and the grate-actuating mechanism caused by overheating, when the ash bed becomes too thin. The product gases from the gasification chamber may be used as raw synthesis gas for the production of, for example, methanol or as furnace heating gases.

Abstract: An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate.

Abstract: A rotary continuous ash discharge stoker having a circular grate which is designed to support burning fuel as it distributes the fuel from the feedpoint over the entire grate, and at the same time provides for the controlled admission of air for combustion of the fuel and also automatically removes from the furnace the remaining ash. The upper grate surface consists of two zones, a central stationary section and an outer rotating section or ring. The central section is inclined and is the main air admitting zone. The outer rotating ring serves to distribute the fuel in the furnace with the aid of a stationary spreader arm, admits the air necessary to complete combustion of the fuel and removes the burned out ash from the furnace with the aid of a stationary ash plow.

Abstract: A slag breaker of a pressure-type coal gasifier having a rotary grate with a plurality of grate segments, a generator bottom and an ash separator, has an inclined breaking plate arranged to be located immediately below the grate segment and prior to the ash separator and provided with a plurality of breaking projections, and a wear sheet arranged to be located on the generator bottom and provided with a plurality of breaking webs.

Abstract: The invention concerns a method and an installation for preparing a combustible gas mixture from solid or liquid fuels by means of a rotatable cup-shaped, perforated bowl forming a supporting grate with a fuel supply to its inner wall and a feed of gasifying fluid to the outer side of the grate, an intermediate layer of a refractory material being formed against the inner wall of the rotating grate for supporting the fuel and finally dividing the gasifying fluid.

Abstract: The invention relates to a gas generator with fixed bed and reverse draught, to gasify solid combustible materials.The gas generator according to the invention comprises starting from the top downwards, a loading compartment, a drying and pyrolysis enclosure, a combustion chamber, a rotary hearth plate and an ash tray. The wall of the combustion chamber is lined with a coil inside which flows part of the combustion air which is injected obliquely on the top periphery of the chamber. The center of the combustion chamber is occupied by a core which is driven in rotation by the hearth plate and which is covered by a deflector. Another part of the combustion air is injected through the core at the top of the combustion chamber.The invention finds an application in the gasification of all types of combustible solid material, which may or may not be associated to their carbonization.

Abstract: The invention discloses an apparatus for maximizing the uniformity of distribution of gasification medium in a rotary grid generator. To insure proper input, a distribution head is rotatably mounted within the interior of the rotary grid, and the distribution head is connected by means of elastic input conduits to either openings which are directly connected with the reactor chamber, or to distribution chambers in the individual segments of the rotary grid. Through use of the apparatus, the formation of canals through preferential gas flow in the solid beds of pressure gas generators is eliminated.

Abstract: Method and apparatus for feeding an oxidant such as air and/or a fuel rich gas within the confines of a substantially air tight enclosure employed in the heat treatment of volatile containing materials which are deposited on the floor of a rotary hearth mounted within the enclosure. A larger number of air and/or fuel rich gas inlet ports are provided in the roof of the enclosure at the outer periphery thereof than at the central or intermediate areas of the enclosure to thus provide a more oxidizing atmosphere at the outer peripheral area of the enclosure than at the central and intermediate areas of the enclosure. The oxidant is admitted into the furnace enclosure through concentrically arranged rows of inlet openings formed in the roof of the enclosure.

Abstract: An improved grate construction for a fixed bed coal gasifier comprises an interrupted generally cylindrical platform including a plurality of sector-like portions and rotatable means, e.g. a stirrer, mounted for rotation adjacent the upper surface of each platform portion. The upper surface of each portion is inclined upwardly in a circumferential direction to an upper leading edge thereof from which an upright wall depends. The stirrer is rotated in the opposite circumferential direction for cooperating with the depending walls to reduce the size of clinkers and for promoting movement of solids from the shaft over the platform.

Abstract: An automated poking system includes a plurality of pokerod assemblies positioned around the periphery of a two-stage, fixed-bed coal gasifier at two separate elevations. Each pokerod assembly includes an elongated pokerod selectively actuatable to extend into the coal bed within the gasifier, and appropriate sensors to provide data relating to the temperature of the coal bed, the resistance encountered by the pokerod, and the position of the pokerod. Alternatively, the temperature sensing function is separate from the pokerod activation, and the coal bed temperature is continuously moinitored. The mechanism for controlling activation of the pokerod may be a hydraulic cylinder-piston device or an electric motor driving the pokerod via mechanical means, such as a rack and pinion apparatus. Poking of the lower zone coal bed agitates the bed, detects and breaks up clinkers, and monitors the coal bed temperature.

Abstract: A method and apparatus for disposal of rubber wastes is provided wherein rubber wastes such as scrap tires are dry-distilled in a vertical dry distillation retort of an internal heating type having a rotary discharge chute with a water seal, valuable substances contained in the rubber wastes, such as carbon black and oil, are effectively recovered and dry-distilled gas is used as a heat source for the dry distillation of the rubber wastes.