1915results about "Solid fuel combustion" patented technology

Various methods for decreasing the amount of nitrogen oxides released to the atmosphere as a component of combustion gas mixtures are provided. The methods specifically provide for the removal of nitric oxide and nitrogen dioxide (NOx) from gas mixtures emitted from stationary combustion systems. In particular, methods for improving efficiency of nitrogen oxide reduction from combustion systems include injecting metal-containing compounds into the main combustion zone and/or the reburning zone of a combustion system. The metal containing compounds react with active combustion species, and these reactions change radical concentrations and significantly improve NOx conversion to molecular nitrogen. The metal-containing additives can be injected with the main fuel, in the main combustion zone, with secondary or reburning fuel addition, or at several locations in the main combustion zone and reburning zone. Optionally, nitrogenous reducing agents and/or overfire air can be injected downstream to further increase NOx reduction.

A method for torrefaction of wood which includes providing a first endless conveyor belt; heating the first endless belt; and positioning a planar wood product on the first belt to heat the wood product by conduction to achieve torrefaction. Other forms provide a second endless belt that disposed in sandwich relation to wood to be torrefied. Some embodiments of the method provide a metal chamber having opposed planar sides dimensioned and configured for receiving a wood sheet with the respective opposed sides of the wood sheet in intimate thermal contact with respective opposed sides of the metal chamber. Other embodiments include the apparatus for torrefaction of an associated wood sheet.

Heating units, drug supply units and drug delivery articles capable of rapid heating are disclosed. Heating units comprising a substrate and a solid fuel capable of undergoing an exothermic metal oxidation reaction disposed within the substrate are disclosed. Drug supply units and drug delivery articles wherein a solid fuel is configured to heat a substrate to a temperature sufficient to rapidly thermally vaporize a drug disposed thereon are also disclosed.

A system 26 for removing elemental mercury or mercury compounds handles carbonaceous sorbent 28 of a starter batch stored in a silo 30 in an agglomerated state. The sorbent 28 is fed by a feeder 32 to a separation device 34, which comminutes (if necessary) and de-agglomerates the sorbent particles 28 to their primary size distribution. This device 34 may be a particle-particle separator or a jet mill, where compressed air or high-pressure steam is the energy source. The de-agglomerated sorbent 28 of a contact batch created from the starter batch is conveyed by an airsteam for injection at a contact location 66 in a flue gas duct whereat carbonaceous sorbent of the contact batch adsorbs mercury from the flue gas.

A system and process to provide integrated control for the pyrolytic composition of organic (biomass) waste products especially for municipal solid waste systems. The system includes integrated control that monitors biomass waste stream throughout the entire system and the products produced therefrom and includes presorting, controlling the amount of material processed in a continuous manner, shredding, removing moisture in a continuous process that is controlled and providing the waste stream to the distillation unit for pyrolytic action where it is converted into gaseous fuel and a char residue. The gaseous fuel is scrubbed clean and monitored and stored and reused to provide heat to the system. The entire system may be self-sustaining and continuous with very little or no human intervention. An integrated real time computer control system includes sensors and measuring devices with all the major components to ensure integrated efficiency.

Pyrolyzing gasification system and method of use including primary combustion of non-uniform solid fuels such as biomass and solid wastes within a refractory lined gasifier, secondary combustion of primary combustion gas within a staged, cyclonic, refractory lined oxidizer, and heat energy recovery from the oxidized flue gas within an indirect air-to-air all-ceramic heat exchanger or external combustion engine. Primary combustion occurs at low substoichoimetric air percentages of 10-30 percent and at temperatures below 1000 degrees F. Secondary combustion is staged and controlled for low NOx formation and prevention of formation of CO, hydrocarbons, and VOCs. The gasifier includes a furnace bed segmented into individual cells, each cell is independently monitored using a ramp temperature probe, and provided with controlled air injection. Gasifier air injection includes tuyere arrays, lances, or both. The oxidizer includes three serially aligned stages separated by air injecting baffles, and ability to adjust the exit air temperature.

A self powered pelletized fuel heating device comprising a thermal electric generator (TEG) unit therein powering a typical collection of low voltage system components including a storage power unit. Non-typically, the heating device requires no external power supply and relies on thermodynamic principles using the pelletized fuel as a heat source. The TEG is configured and positioned optimally for conventional operation and installation requirements without modification to normal form or function.

PCT No. PCT/JP97/00573 Sec. 371 Date Jan. 12, 1998 Sec. 102(e) Date Jan. 12, 1998 PCT Filed Feb. 27, 1997 PCT Pub. No. WO97/32161 PCT Pub. Date Sep. 4, 1997According to the present invention, boiler water is pressurized so that its boiling point is set at approximately 200 DEG C. to 320 DEG C. The boiler water is heated in at least two stages. Thermal energy of gases containing chlorine compounds is used to heat the water to its boiling point. Thermal energy of gases which do not contain chlorine compounds is used to heat the water from its boiling point until superheated steam of a given temperature is generated. The heating which uses the thermal energy of gases containing chlorine compounds is accomplished using the thermal energy from the combustion of pyrolysis gases obtained from a pyrolysis means in which waste material is supplied into a chamber containing a fluidized bed medium which has been heated to at least 300 DEG C., and a pyrolytic reaction is induced. The heating which uses the thermal energy of gases which do not contain chlorine compounds is accomplished using the thermal energy obtained from a char combustion means to combust char in which a char mixture consisting of unpyrolyzed residue and fluidized bed medium removed from the pyrolysis means is fluidized by a stream of air, and the unpyrolyzed residue is combusted.

This invention provides a portable combustion device that provides a cleaner combustion, reduces the kindling period, and provides a more efficient overall combustion through the use of a fan that directs a predetermined volume of airflow over the combustible fuel—typically wood or similar cellulose-based biological solids. The combustion device has a combustion chamber into which the fuel source is placed for combustion. Mounted to the side of the combustion chamber is a housing that encloses the TEG, which generates an electrical output based on a difference in temperature on opposing sides. Mounted onto the TEG housing and protruding into the combustion chamber through a small passageway is a heat-conducting probe and heat-conducting probe base unit. The opposing side of the TEG is also in contact with a heat sink to remove heat from the TEG device through interaction with ambient air that passes over the vanes from a port located along the side of the TEG housing. A motor and fan near the heat sink to draw air away the heat sink and aid in the cooling of the heat sink, and force air onto the combusting fuel through a plurality of peripheral ports that connect with an air space located between the inner and outer walls of the combustion chamber.

A steam-generating combustion system includes an oxygen enriched gas provided as at least part of an oxidant stream. A combustion chamber receives and combusts a fuel in the oxidant stream and generate steam. The combustion chamber generates flue gas having a flue gas volume which is smaller than a volume of flue gas generated by the combustion chamber when operated with air as the oxidant stream. A flue gas pollutant control system receives the flue gas from the combustion chamber and reduces at least one of particulate matter, SO_x, NO_x, and mercury. The reduction in flue gas volume allows the implementation of much smaller pollutant control equipment, since the size of the pollutant control units is mainly based on the volume or mass flow rate of flue gas to be treated. Moreover, the system including oxygen-enriched gas in the oxidant will lead to concentrated levels of the pollutants in the flue gas. The high concentrations of pollutants will enhance their absorption in the different pollutant control systems, improving removal efficiency for all species.

A fluid heat exchange system with a fluid flow circuit having a heat exchange fluid flow loop, a heat absorption component (as in a domestic hot water tank inclusive of small commercial use tanks as in tanks of 20 to 120 gallons), a heat exchanger and preferably also a pump. A controlled and automated fuel supply source based heater (as in a pellet stove) is in heat passage communication with the said heat exchanger. A control unit triggers activation of the pump upon fluid in the heat absorption component reaching or dropping below a preset temperature, and the fluid flow circuit is arranged such that, during times of non-activation of the pump, fluid is free to flow in a unidirectional flow within the fluid circuit based on thermodynamic temperature differentials alone. A retrofitting of a domestic hot water tank is also featured preferably making use of preexisting drain and safety vent porting for in-feed and out-feed porting in the exchange loop side. Also, the flow circuit preferably is free of check valves and steam accommodation equipment.

Various smoke and combustible gas combustors (200, 300) are disclosed, and also disclosed are systems (100, 200) combining gas combustor with inventive burner. Such a burner (100 or 100') provides combustion of a particulate fuel such as sawdust, and many types of varying moisture content biomass fuels such as poultry litter. The combustors and burners exhibit a high turndown ratio ["TDR"].The smoke or combustible gas combustors (200, 300) are combined synergistically with such a burner (100, 100'), or combined with another suitable burner, so as to provide high temperature burner output gases to the combustor, which has coaxial inner and outer combustion chambers (352, 356) inlet tuyere(s) connected to the inner combustion chamber for introducing combustible smoke or other gases to be burned into the inner combustion chamber at one end thereof with cyclonic flow, and in which combustion air is mixed with combustible smoke or other gases to form a gas stream moving through the inner combustion chamber with cyclonic movement. A preheat tube (331) within the combustible gas heating chamber receives heated exhaust gases from the burner, and communicates with the inner combustion chamber exit through a plurality of apertures (364) for controlled flow of said heated exhaust gases into the gas stream and so heating same by mixing the exhaust gases with the stream of air and combustible gases.

The burner preferably exclusively burns substantially explosible solid fuels and preferably has instant ON-OFF thermostat control, wastes no energy preheating the enclosure or external air supply, achieves stable combustion the moment the powder-air mix is ignited in our burner, is used in the upward vertical mode except for oil burner retrofits, burns a solid fuel in a single-phase regime as if it were a vaporized liquid or gas, is designed to complete combustion within the burner housing itself rather than in a large, high temperature furnace enclosure which it feeds, has an ultra-short residence time requirement, is a recycle consuming burner with self-contained management of initially unburned particles, is much smaller, simpler and lower cost, has a wider dynamic range/turndown ratio, is more efficient in combustion completeness and thermal efficiency, and operates with air-fuel mix approximately at the flame speed.

A waste gas treatment system having a burner part and a combustion chamber provided at a downstream side of the burner part. Combustion flames are formed from the burner part toward the combustion chamber, and a waste gas is introduced into the combustion flames, thereby oxidatively decomposing the waste gas. The combustion chamber is formed from an inner wall made of a fiber-reinforced ceramic material. Therefore, the wear of the inner wall due to heat and corrosion is minimized, and thermal stress cracking is also reduced. Consequently, the lifetime of the system increases, and the cost of equipment and the availability factor can be improved. In addition, because the inner wall exhibits no catalytic effect, the formation of thermal NOx is suppressed, and it is possible to achieve environmental preservation and to simplify the treatment equipment.

Process and apparatus are provided for a high energy efficiency chemical combustion process. The process provides two reaction steps, both of which are exothermic. First, a reduced oxygen carrier is contacted with oxygen in a reactor to form an oxidized oxygen carrier, such as metal oxide or metal suboxide, and then the oxidized oxygen carrier is fed to a second reactor and combusted with a fuel. The reaction produces the reduced oxygen carrier and carbon dioxide. The reduced oxygen carrier from the second reactor is recycled back to said first reactor. Carbon monoxide can also be produced during the process depending on stoichiometric amounts of the reactants. Though the process can be performed in various types of reactor systems, one preferred embodiment is the flash furnace with the production of fly ash during combustion. The process is highly efficient and produces a large amount of usable work.

Methods and apparatus for pollution control which are well suited for use in a coal power plant are described. Ash is collected and injected into the flue gas stream at a location upstream of a cooling module. The ash acts as an absorbent and/or reactant material onto which condensate may condense. By re-introducing ash to keep the condensation forming wet areas within the system, lower cost materials which are less corrosion resistant than needed for wet operating conditions can be used. Mercury recovery and SO3 removal is facilitated by the cooling process and re-introduction of collected ash. Activated carbon and/or an alkali absorbent material may be added. Use of a dry ESP and/or fabric filter as opposed to a wet ESP for particulate collection leads to cost benefits. Energy recovered by the cooling of the flue gas may be re-used to heat turbine condensate leading to improved energy efficiency.

This invention provides a portable combustion device that provides a cleaner combustion, reduces the kindling period, and provides a more efficient overall combustion through the use of a fan that directs a predetermined volume of airflow over the combustible fuel—typically wood or similar cellulose-based biological solids. The combustion device has a combustion chamber with a fuel source. A housing encloses the TEG on the side of the device that generates an electrical output based on a temperature differential between opposing TEG sides. A heat-conducting probe is mounted to the TEG and protrudes into the combustion chamber. The opposing TEG side contacts a heat sink that interacts with ambient air. A fan draws heated air away the heat sink, and forces the air onto the combusting fuel through a plurality of peripheral ports that connect with an air space located between inner and outer walls of the combustion chamber.

A process for mitigation of fouling deposits within a combustion zone, capturing of toxic metal emissions, and reduction of visible sulfur emissions attributable to sulfuric acid mist during coal combustion. SO₃ formed during coal combustion is reduced by the addition to the coal of raw, unprocessed magnesium-containing minerals such as magnesite ore or brucite ore. The minerals are pulverized to a fine particle size and combined with pulverized coal to provide a mixture of the particles. The mixture is combusted and the ore particles calcine and decrepitate to very fine magnesium oxide particles that have a significant particle surface area. The magnesium oxide particles react with the SO₃ produced during combustion of the coal and also capture toxic metals to reduce the quantity of undesirable stack discharge components.

Inductively coupled plasma (ICP) reforming converts carbonaceous compounds into a fuel for use in generating electrical power. Energy rich hydrocarbon fuels, such as coal, marine diesel, oils, and hydrocarbon wastes are employed as a feedstock for the ICP, which transforms the feedstock into a fuel that can be used by fuel cells and gas turbines for the production of electricity. The overall efficiency of an ICP-based electrical power system can be increased by providing partial oxidation within the reaction vessel. The partial oxidation conditions consume a small amount of the reformed fuel gas, thereby liberating sufficient thermal energy to reduce the electrical power requirements of the ICP to maintain desired reactor temperatures, and providing an increase in the overall net electrical power production. The integrated power production system can also adjust to meet an increased requirement for process heat and steam by balancing the effect of partial oxidation.

A precombustor having a chamber having a first end and a second end, and an inlet configured to deliver a substantially parallel flow of solid fuel surrounded by oxygen at the first end. The first end further includes a recirculation step and the second end fluidly communicates with a furnace. The inlet and the recirculation step are arranged to form a recirculation zone of at least a portion of the solid fuel and the oxygen. A combustion system and method for operating a combustion system are also disclosed.

A multi-sided, portable outdoor fireplace convertible to an open grill, a rotisserie assembly, and a smoker assembly, the fireplace includes a carriage assembly with a pair of rotatable wheels and at least one leg member; a base pan assembly for containing a solid fuel heat source affixed to the carriage assembly; and a removable screen assembly residing on top of the base pan assembly. When converted to an open grill, the fireplace further includes a grill bracket removably attachable to the screen assembly. When converted to a smoker, the fireplace, in one embodiment, further includes at least one heat/wind shield attachable to the screen assembly; a smoker adaptor body residing on the screen assembly; an adjustable grate support bracket affixed to the interior of the smoker body and a cover.

A fuel flexible furnace, including a main combustion zone, a reburn zone downstream from the main combustion zone, and a delivery system operably coupled to supplies of biomass and coal and configured to deliver the biomass and the coal as ingredients of first and reburn fuels to the main combustion zone and the reburn zone, with each fuel including flexible quantities of the biomass and/or the coal. The flexible quantities are variable with the furnace in an operating condition.

The present invention provides combustion products of hydrocarbon fuels and controlled amounts of metal oxide strength enhancing materials. The combustion products are useful as additives to cementitious materials. A hydrocarbon fuel such as coal is introduced into a combustion chamber and selected amounts of materials comprising CaO, SiO₂ and Al₂O₃ are also introduced into and/or downstream from the chamber. The hydrocarbon fuel undergoes combustion while the metal oxide strength enhancing materials react with each other and/or the ash or other reaction products of the hydrocarbon fuel. The combustion products have been found to significantly increase compressive strengths of cements such as Portland cement. A reduction in SO₂ emission levels also results from the introduction of the metal oxide strength enhancing materials into the combustion process.

A method and an apparatus for optimizing the combustion air system in a power boiler or chemical recovery boiler by improving fluid flow and gas mixing are disclosed, whereby one can increase boiler capacity and combustion uniformity and reduce particulate and gaseous emissions. The method involves interlacing of the secondary and, where applicable, the tertiary air supply through opposing air ports on all four walls of the boiler, and is implemented by alternately opening wide or partially closing a port damper on one side, while partially closing or opening wide a port damper on the opposite side, such that a 70-100% open damper on one side opposes a partially closed (10-40% open) damper on the other and vice versa in an alternating fashion, along opposing walls. In a preferred embodiment, the optimization is further enhanced by balancing primary air flow, achieved by adjusting port dampers and windbox pressures so that the primary air flow is evenly distributed between opposite walls, between all four walls of the boiler and between individual airports on each wall. Windbox pressure and other key measurements of boiler operation ensure proper balancing and an adequate interlacing of air flows at the primary, secondary and tertiary elevations, respectively.

Apparatus and method for enhancing combustion comprises an enclosure defining an opening for introduction of a gas and openings for the introduction of air, with a nozzle in the opening for introduction of a fuel gas into the enclosure. First and second electrodes are located in the enclosure, the first and second electrodes being coated with dielectric material, and being connected to an electrical power supply. With electrical power applied to the first and second electrodes and with the fuel gas sprayed into the enclosure, an atmospheric pressure plasma created by a dielectric barrier discharge is produced in the enclosure that cracks the fuel gas prior to its mixing with air introduced through the openings for the introduction of air.

A control system for controlling the utilization of heated waste streams for fluidizing particulate matter such as coal in a fluidizing bed dryer. The control system includes a number of graphic user interfaces that allow an operator to more easily monitor and/or control the various regulator devices. The control system controls coal handling or transportation, fluid handling or flow, and the discharge of discarded or separated coal from the dryer.

The invention described is a process for improving the performance of a commercial coal or lignite fired boiler system by supplementing its normal coal supply with a controlled quantity of thermally beneficiated low rank coal, (TBLRC). This supplemental TBLRC can be delivered either to the solid fuel mill (pulverizer) or directly to the coal burner feed pipe. Specific benefits are supplied based on knowledge of equipment types that may be employed on a commercial scale to complete the process. The thermally beneficiated low rank coal can be delivered along with regular coal or intermittently with regular coal as the needs require.

An improved combustion method and corresponding apparatus is disclosed, where the method includes oxidizing a fuel in a combustion chamber with an oxidizing stream including an air stream and a first recycled flue gas stream and mixing a produced hot flue gas stream with a second recycled flue gas stream to form reduced temperature flue gas stream which can be used directly in a power generator or to heat a reactor. The method and apparatus allow flow rates of the streams to be adjusted so that temperatures in the combustion chamber and in the heat transfer unit or units of the power generator or reactor can be kept below temperature that would thermally damage the combustion chamber, heat transfer unit or units or the reactors.

A portable pellet fired heating element for mounting to a grill or stove and comprising a gravity fed pellet holder, a unitary tubular structure having a burner, an air intake and an exhaust chute. Fuel may be supplied to the pellet holder by various supply means such as a conveyer, ramp, scooped, held in bulk in a hopper, and like pellet supply structures and methods. Fuel is fed to the air-cooled insulated burner area onto a decomposer grate, which defines the primary combustion area and which is partially open to the atmosphere for air intake. An adjustable high-pressure flow of gas or vapor is introduced to the primary exhaust chute below the decomposer grate to create a low pressure flow above the grate and which upon ignition, cause flames to be pulled into the pellet mass on the grate. In operation, air from the primary air intake maintains hot charcoal in the primary combustion area, and the secondary combustion area provides a steady flow of wood gas that mixes with a predetermined or adjustable amount of air supplied by the secondary air intake to maintain the flame. The super heated gasses and any ash are provided to the grill or stove by means of the exhaust chute. For cleaning purposes, an electrical/mechanical device may be provided to move the decomposer grate or to provide a sudden burst of high gas pressure.

A new and unique boiler and method of transition between air and Oxy-combustion in a coal fired combustion process wherein near pure oxygen may be introduced to the boiler furnace in several locations including directly into the flame through the burner and/or directly into the furnace as nearly pure oxygen, and/or into the recycle flue gas streams to the burners, including both primary and secondary streams.