Abstract: A method of operating a fixed-bed gasifier includes positioning a tapping element at a first point above a bed of fuel particles, lowering the tapping element into the fuel particles along a first linear path to form a first linear passage in the fuel particles, raising the tapping element to retract the tapping element from the fuel particles along the first linear path so that the tapping element exits the fuel particles from the first linear passage, positioning the tapping element at a second point above the fuel particles, lowering the tapping element into the fuel particles along a second linear path to form a second linear passage in the fuel particles, and raising the tapping element to retract the tapping element from the fuel particles along the second linear path so that the tapping element exits the fuel particles from the second linear passage.

Abstract: A fixed bed gasifier has a clinker breakup device. The tapping element of the clinker breakup device can be positioned at different points, allowing the tapping element to be small but capable of reaching all regions of the fuel particle bed. The tapping element intermittently enters the fuel particle bed in gasifying operation. Before it re-enters the bed, the drive mechanism adjusts the position of the tapping element so that it does not enter the same tapping channel again. Repeated local spiking at different times and locations moves the gasifier bed and disrupts the sintering of clinker particles that can block the gasifier cross section. Gas continues to flow through individual zones over the entire cross section, and not just in the tapped channel. Lumps of clinker that have sintered together are conveyed onward—toward the support device—or else broken up.

Abstract: A heat exchanger for cooling product gas generated from biomass includes a cylindrical main body, a rod-shaped component, a gas inlet and a gas outlet. The cylindrical main body has a circumferential cladding. An annular flow channel is formed in the cylindrical main body around the rod-shaped component, which extends axially in the main body. The gas inlet and gas outlet are disposed towards opposite ends of the main body. The gas inlet is tubular and enters the annular flow channel tangentially to the circumferential cladding and perpendicularly to the axial direction of the cylindrical main body. The velocity of the cooling product gas is maintained by making the cross-sectional area of the gas outlet smaller than that of the gas inlet. A helical shaped guide plate is disposed in the annular flow channel and has an outer circumferential edge that seals against an inner surface of the circumferential cladding.

Abstract: A cyclone separator for separating particles from a gas flow includes a gas inlet and a separating element. The separating element includes an upper cylindrical section connected to a gas outlet and a lower conical section connected to a particle outlet. The first end of the gas inlet is on a straight section, and the second end of the gas inlet in on a helical section. The second end is connected to the upper cylindrical section. The cross-sectional area of the gas inlet continually decreases, and the vertical or longitudinal dimension of the gas inlet continually increases from the first end towards the second end. The vertical dimension at the second end equals the diameter of the upper cylindrical section. A guide plate inside the straight section distributes the particles over the increasing vertical dimension of the gas inlet and prevents the particles from concentrating centrally in the gas flow.

Abstract: A rotary grate with slit-shaped openings is used in fixed-bed gasifier that produces a product gas from biomass particles. The rotary grate supports the biomass particles. Each slit-shaped opening has a cross-section that conically widens in the direction from the upper to lower side of the grate. The slit-shaped openings act as planes to break up ash supported by the grate as a drive shaft rotates the grate. As the grate rotates, a dome-shaped covering in the middle of the grate causes ash to be spun laterally away from the middle and into the region of the grate where the slit-shaped openings are located. The slit-shaped openings extend concentrically around the middle of the grate. The combined open area of the slit-shaped openings on the upper side of the grate makes up between 20% to 40% of the grating surface area outside the dome-shaped covering on the upper side.

Abstract: A downdraft fixed-bed gasifier for producing product gas from pourable biomass particles includes a gasifier container, a gasifier component, a feeder, an air supply inlet, a grate and a product gas vent. The gasifier container has a larger diameter than does the gasifier component. The lower open end of the gasifier component extends down into the gasifier container. The feeder is adapted to receive biomass particles into the upper closed end of the gasifier component. Combustion air is fed into the gasifier component through the air supply inlet located near the upper closed end. The grate supports the biomass particles and is disposed in a lower portion of the gasifier container below the lower open end of the gasifier component. Product gas generated from oxidizing the biomass particles exits the gasifier container through the product gas vent located in the side of the container below the level of the grate.