35 results about "Downdraft gasifier" patented technology

A method for using a downdraft gasifier comprising a housing and a refractory stack contained within the housing. The refractory stack may comprise various sections. Apertures in the sections may be aligned to form multiple columnar cavities. Each columnar cavity may comprise an individual oxidation zone. The method of use may include the steps of placing a feedstock into an upper portion of the refractory stack, measuring the temperature of each columnar cavity, and adjusting the flow of oxygen to a particular columnar cavity to maintain the temperature of the particular columnar cavity within a particular range.

A downdraft gasifier is disclosed. The gasifier includes a biomass section that accepts and stirs raw biomass materials, a pyrolysis and tar cracking section having an inner cylinder for receiving biomass and an outer surrounding cylinder for gases from the biomass, and a char gasification section for receiving biomass and gases from the pyrolysis and tar cracking section. The char gasification section provides a grating and scraper for passing gases and ash and retaining biomass for char gasification on the grate.

The invention includes a downdraft gasifier having a rotatable auger / grate extending through its reduction zone. The auger at times moves biofuel through the gasifier and at times supports it in the gasifier. A frusto-conical biomass grate funnels biomass onto the auger and is perforate for permitting the passage of gases while retaining the biomass. A guide tube surrounds the auger below the frusto-conical biomass grate. The invention also includes mixing gas or solid particulate fuel in a conduit segment that houses a mixing chamber. Fuel is fed through a fuel inlet port into the mixing chamber. High velocity combustion air from a blower is forced into the mixing chamber through a restricted orifice that generates a suction pressure for drawing gas or solid particulate fuel into the mixing chamber. A combustion chamber supply conduit delivers fuel from the mixing chamber into a burner.

An entrained flow gasifier designed as a component for an Integrated Gasification Combined Cycle plant of optimized efficiency is provided. The raw gas initially flows through a waste heat unit designed as a radiation cooler and subsequently flows through a full water quench. This results in a higher ratio of steam in the raw gas, which decreases the medium-pressure steam supply before the water-gas shift and thus improves efficiency in IGCC plants with CO2 separation.

In a reactor for the gasification of solid and liquid fuels in the entrained flow at temperatures between 1200 and 1900° C. and pressures between ambient pressure and 10 MPa with an oxidizing agent containing free oxygen, the cooling screen is connected in a gas-tight manner to the pressure shell via a bellows compensator to accommodate linear deformation. Continuous sweeping by gas of the annular gap between pressure shell and cooling screen is unnecessary and backflow by producer gas is prevented.

The invention discloses a downdraft gasifier with a tar degrading function. The downdraft gasifier comprises a hearth, wherein the lower part of the hearth is provided with a ring-shaped throat; a feeding hole is formed in the top of the hearth, and an ash outlet is formed in the bottom of the hearth; upper, middle and lower three-level tangential primary air distribution outlets are axially formed in the wall above the ring-shaped throat of the hearth; a tubular fire grate is arranged between the ring-shaped throat at the lower part of the hearth and the ash outlet at the bottom and is formed by hollow steel tubes spaced from each other; holes as secondary air distribution outlets are drilled in the hollow steel tubes; a vertical flue is arranged outside the hearth; one end of a horizontal flue flush with the tubular fire grate is communicated with the hearth and the other end is communicated with the vertical flue; a gas outlet is formed in the upper part of the vertical flue; a calcium base catalyst jet device is arranged at the top of the vertical flue. The downdraft gasifier has a simple structure, has a tar self-purifying capacity and can ensure that the tar in the gasified gases is fully decomposed before leaving the hearth, thus obtaining the gasified gases with relatively high quality.

The invention provides an air distributing and ash discharging device of an upward suction type gasifier. The air distributing and ash discharging device comprises enamel and a gasification bucket. A body of the gasification bucket is in the shape of a funnel with the upper portion larger than the lower portion, the inclination angle of the funnel is alpha, and alpha is smaller than or equal to 60 degrees. The enamel is arranged at the top of the body, and gasifier legs are arranged below the enamel. A slag smashing pipe is arranged in the middle of the gasification bucket, an electronic ignition pipe is arranged on the lower portion of the gasification bucket, an ash storage box body is arranged at the bottom of the gasification bucket, and an inner barrel communicated with the gasification bucket is arranged on the upper portion of an inner cavity of the ash storage box body. An air distributing plate is arranged at the top of the inner barrel, a plurality of small holes are evenly distributed in the center of the air distributing plate, the diameter of the small holes is zeta, and phi 3<=zeta<=phi 12. The sum of the areas of the small holes is equal to or smaller than the cross sectional area of an air inlet pipe. An ash control plate is arranged at the bottom of the inner barrel, the ash control plate and the air distributing plate are used in cooperation, the discharging amount of ash is controlled, the parallel distance between the ash control plate and the air distributing plate is xi, and 90 mm<=xi<=240 mm.

Embodiments of the invention are directed toward a coaxial gasifier for enhanced hydrogen production, comprising: downdraft gasifier comprising a hot zone for converting biomass to synthesis gas; and a coaxial gas converter disposed within the downdraft gasifier, the coaxial gas converter comprising a biochar inlet valve, a coaxial char tube, and a biochar and ash outlet valve.

The invention provides a closed updraught type fixed bed gasification furnace waste heat recycling device. The closed updraught type fixed bed gasification furnace waste heat recycling device comprises a material storage cabin, wherein the material storage cabin is arranged at the top of a pyrolysis gasification furnace; a feeding hole is formed in the lower side of the material storage cabin; the feeding opening corresponds to a spiral feeding device and is used for conveying materials into a pyrolysis gasification chamber of the pyrolysis gasification furnace; a fire grate and an ash discharging opening are arranged on the lower part in the pyrolysis gasification chamber; a flue gas flow guide plate is arranged on the upper part of the pyrolysis gasification chamber; pyrolysis gas of the pyrolysis gasification chamber is introduced into the waste heat recycling device to be subjected to heat exchange; after oil tar in the pyrolysis gas is cooled, the oil tar flows into an oil tar storage chamber, and the cooled pyrolysis gas after the heat exchange passes through a gas purifier and is discharged out from a pyrolysis gas outlet; an oil tar flow guide plate is horizontally arranged in the middle of the oil tar storage chamber; a discharging pipe of the waste heat recycling device is connected with an air inlet; outdoor air enters the discharging pipe of the waste heat recycling device from the air inlet and is subjected to the heat exchange with the pyrolysis gas; and the air subjected to the heat exchange is used for providing a gasification medium for the pyrolysis gasification chamber through an air outlet; and after the gasification medium and the materials are mixed and combusted, heat is provided for pyrolysis, gasification and drying in the furnace.