Abstract: A method of combustion and a combustion plant in which absorbent is regenerated is described herein. During the combustion of a fuel in a combustion chamber enclosing a fluidized bed, a fuel and an absorbent are supplied to the fluidized bed. The combustion gases generated during the combustion are collected and purified in a separating member by separation of solid material from the combustion gases. The separated solid material is recirculated to the fluidized bed through a channel, and a gaseous medium is supplied in a controlled manner to the separated solid material present in the channel in order to displace the combustion gases and provide a chemical reaction.

Abstract: A method of combustion in a pressurized, fluidized bed and in the freeboard thereof. The combustion method is further characterized by the recirculation of solid sulfur absorbing materials. A gas channel, designed so as to prevent fluidizing gas from entering the channel from below, is provided such that it opens to the freeboard and to a separating member which separates particulate matter from the combustion gasses.

Abstract: A power plant comprises a combustion chamber (1), in which combustion of a combustible matierla is intented to take place while forming hot combustion gases, a gas turbine device (13, 14, 20, 27, 30) which is arranged to be driven by the combustion gases, and a topping combustor (8, 23) which is arranged to receive the combustion gases and increase a temperature thereof to a level suitable for the gas turbine device. Furthermore, there is a gasifying reactor (10) which is arranged to produce a combustible gas for combustion in the topping combustor (8, 23) in order to accomplish said increase of temperature. The gasifier (10) is connected to a conduit member (18) which is arranged to supply an oxygen-containing gas, needed for the gasification, to the gasifier, and which comprises means (34, 35, 36, 37) which are arranged to affect the flow of said oxygen-containing gas, supplied to the gasifier (10), to a desired level.

Abstract: A power plant is disclosed having a combustion chamber (1) in which the combustion of a combustible material is performed, while forming hot combustion gases to drive a gas turbine device (14, 20, 27). A topping combustion device (8, 23) is arranged to receive the combustion gas and raise its temperature to a level suitable for the gas turbine device. A gasifying reactor (1) is arranged to produce a combustible gas for combustion in the topping combustion device (8, 23). A first conduit member (18) is arranged to supply an oxygen-containing gas, necessary for gasification, to the gasifying reactor (10) and a second conduit member (9) is arranged to supply the combustible gas from the gasifying reactor (10) to the topping combustion device (8, 23). A member (35) is arranged at the second conduit member (9) and adapted to cool down the combustible gas supplied to the topping combustion device (8, 23).

Abstract: A combustion plant for a combustion process is disclosed. The plant has a pressurized combustion chamber (1), which encloses a fluidized bed and in which combustion of a fuel is to take place while producing combination gases, a gasifying device (40), which is arranged to produce a combustible gas and a degassed combustible product, and a transportation device (6, 44) for discharging the product from the gasifying device (40) and supplying it to the combustion chamber (1) for combustion of the product in the combustion chamber. The transportation device has a discharge conduit (44) connected to the gasifying device (40) and is arranged to discharge the product from the gasifying device (40). The discharge conduit (44) has a cooling member (45), which is arranged to cool the product discharged from the gasifying device (40), and a pneumatic supply conduit device.

Abstract: To a fluidized combustor bed there is passed particulate fuel via a fuel flow distributor which comprises a vessel for receiving a particular fuel from a fuel storage. The fuel is fed into the vessel of the fuel flow distributor from the fuel storage, whereupon the fuel is fluidized in a bed above a bed bottom in the vessel of the fuel flow distributor. The fuel flow distributor comprises at least two feed pipes with associated inlets located adjacent the surface of the bed in the fuel flow distributor, where fluidization gas which leaves the vessel via a feed pipe feeds out fuel to at least one nozzle is in the bed of the combustor. Additional gas is supplied to the feel pipes at the inlets thereof, such that the flow of fuel through an individual feel pipe can be controlled by controlling the gas flow supplied to the inlets of the respective feed pipes.

Abstract: The present invention relates to a method of supplying coal and sulphur absorbent to a combustor with combustion in a fluidized bed. The coal is crushed and sorted into a fine and a coarse fraction. The fine fraction is mixed with water, possibly with oil and/or emulsifier, into a paste which is pumped into the bed of the combustor via a number of first nozzles. The coarse coal fraction is supplied to the combustor pneumatically in dry state, directly or via at least one lock hopper systems and a number of other nozzles. The invention also relates to a power plant for application of the method.

Abstract: A method and a device are provided for cutting off a gas flow through a filter element in a ceramic filter of high-temperature type upon breakage of the filter element, wherein a pulling member which is fixed to the lowermost part of the filter element causes a valve to be closed upon breakage of the filter element, whereby the outlet of the filter element for normally cleaned gases is closed.

Abstract: A method of heating of bed material in a PFBC plant including a combustor and wherein bed level adjustment due to a load change is accomplished by injecting bed material into or discharging it from the combustor through feeding devices, the method including the steps of arranging two storage vessels, each adapted for injecting the bed material therefrom into the combustor and for storing bed material discharged from the combustor, and heating and maintaining the bed material in the storage vessels at the temperature corresponding to the bed temperature while maintaining the bed level of the combustor constant, by discharging bed material with the temperature of the bed from the combustor via the feeding device adapted for discharge of bed material, into one of the storage vessels with a predetermined feed speed and at the same time and at the same feed speed injecting bed material from the second storage vessel into the combustor via the feeding device adapted for injection of bed material.

Abstract: A method of feeding particulate material into a pressurized fluidized bed combustor including the steps of: feeding the particulate material from a source which is at a substantially lower pressure than that existing in the pressurized fluidized bed combustor into the upper end of an elongate, generally vertical gravity feed conduit constructed to have an inner bore which is substantially smaller at its lower end than at its upper end, and selecting the vertical height of the feed conduit and the extent of reduction in its bore over its length to ensure that the particulate material will move by gravity between the open input end of the conduit and the pressurized fluidized bed combustor notwithstanding the difference in pressure between the pressurized combustor and at the input end of the conduit.

Abstract: A method is provided for cooling of particulate material from a combustion plant, especially intended for cooling of fine-grained dust which has been separated from the flue gases from a PFBC power plant, and in which the material is transported pneumatically with the flue gas as transport means. A cooler is provided at the inlet of which there is a space for separation of the particulate material from the transport gas. The transport gas is removed via a gas cleaner. The particulate material is collected in a duct where it forms a particulate column. The duct includes cooling modules, suitably water-cooled, which cool the material on its way down through the duct. The duct comprises devices for the supply of a gas for stirring the material in the duct while the remaining flue gas is being separated from the particulate column.

Abstract: A pneumatic transport system for transferring particulate material from a first pressurized container to a second container which is under a lower pressure, while successively reducing the pressure, comprising a number of parallel tubes (36), arranged in series, said tubes being joined together at their ends by means of transfer chambers (38) for transferring a gas/material stream from an upstream tube (36) to a downstream tube (36). The transfer chamber (38) are formed with tubular inlets and outlets (52, 56) opening out into a space (54) where a gas/material stream is transferred from the inlet (52) to the outlet (56). Between the inlet (52) and the outlet (56) there is a double-bent unsymmetrical surface, bulging towards the space (54), which conforms to the wall surfaces of the inlet (52) and the outlet (56).

Abstract: The invention relates to a power plant with a combustor (10) with combustion of a fuel in a fluidized bed of a particulate material and with a storage container (36) for hot bed material for adjusting the bed height upon changes of the load by the transfer of bed material from the combustor (10) to the storage container (36) and vice versa. It is primarily intended for a PFBC power plant with the combustor (10) and the container (36) in a pressure vessel (14) filled with compressed combustion air. The container (36) is provided with an internal mantle (66) which surrounds the storage space (40) for the bed material and an internal insulation (68) in the gap (70) which is formed between the container wall (36a) and the mantle (66). The lower part of the mantle (66) is joined to the container wall by means of an outwardly and upwardly directed skirt-like flange (66a-c).

Abstract: In a PFBC power plant having a bed vessel containing a bed of fluidizable particulate material enclosed within a pressure vessel and surrounded by compressed combustion air, a gas turbine-compressor unit driven by combustion gases from the bed vessel, a first cut-off valve in a supply conduit for propellent gas to a turbine; a second cut-off valve in the conduit from a compressor to the bed vessel, a third cut-off valve in a by-pass conduit between the turbine and the compressor, and a blow-off valve in a conduit for dumping combustion gases from the bed vessel, a method of controlling such power plant in the event of an operational disturbance in the turbine unit comprises the steps of isolating the compressor-turbine unit from the bed vessel by closing the first cut-off valve in the supply conduit and the second cut-off valve in the conduit from the compressor to the bed vessel, short-circuiting the compressor-turbine unit by opening the valve in the bypass conduit, dumping the combustion gases by opening t

Abstract: A method for improving utilization of sulphur-absorbent containing calcium, in a power plant burning fuel in a fluidized bed (12) of particulate material in a combustion chamber (11). When fresh absorbent is prepared it is crushed and the crushed material is subsequently divided into a fine and a coarse fraction. The fine fraction is calcinated, mixed with crushed coal (41) and used as drying agent. The invention also relates to a power plant having equipment (28) for calcinating a fine-particled fraction of fresh sulphur-absorbent, and also equipment for mixing coal (41) and the calcinated absorbent and equipment (46, 48) for feeding the mixture of absorbent and coal into the bed. (FIG. 3).

Abstract: A power plant burning a fuel, primarily coal, in a bed vessel with a fluidized bed of a particulate material at a pressure exceeding atmospheric pressure. Consumed bed material and/or ashes separated from combustion gases are removed through a pressure-reducing discharge means. A part of the pressure-reducing discharge means is located in a dryer for crushed coal which forms a bed arranged as a bed vessel where crushed coal to be dried forms a fluidizable bed. The bed is fluidized by gas introduced through nozzles in the bottom of the bed vessel. The discharge portion constitutes a heater for the bed and a cooler for the discharge portion.

Abstract: A power plant utilizing combustion of fuel in a fluidized bed contains a particulate sulfur-absorbing material. A discharge device for bed material and ashes includes a crusher which breaks down the material so that it can be transported away or so that unconsumed absorbent in the bed material is exposed for reuse in the bed. The crusher has a stationary grinding portion and a rotating grinding portion receiving bed material. Scrapers selectively scrape off layers of material during rotation of the rotating grinding portion thus distributing the material around the periphery of the grinding portions.

Abstract: A pressure-reducing device in a pneumatic transport system for particulate material having a first and a second transport channel which are arranged so that, at the transition between the two channels, the gas/particulate flow is bent through 180.degree.. After the bend, a throttling means is arranged. The throttling means consists of an annular nozzle, the inlet side thereof being rounded with an arcuate profile in radial section. The pressure-reducing device may be included in a transportation system for feeding particulate material out from a pressurized container to a container under a lower pressure, for example for removing dust from a dust separator in a PFBC plant to a collecting container.

Abstract: The bed depth in a power plant burning sulfur-containing fuel in a fluidized bed of material which constitutes a sulfur absorbent in a combustion chamber is controlled on the basis of plant power output. A plurality of sensors connected to the combustion chamber determine the existing bed depth. A bed material mill grinds material removed from the bed prior to returning it to the bed, the rate at which the mill operates being controlled by the extent to which the actual bed depth differs from the desired bed depth. The mill grinds some bed material to small enough size for it to be carried from the combustion chamber with the combustion gases.

Abstract: A power plant designed to burn fuel in a bed of fluidizable particulate material contained in a combustion chamber includes a tubular discharge device for bed material or dust separated from combustion gases leaving the combustion chamber. The tubular discharge device is designed as a cooler which is cooled by combustion air flowing into the combustion chamber and is utilized for pre-heating the plant upon start-up from a cold state. At least a part of the tubular discharge device, is electrically insulated from parts located upstream and downstream and from supporting structural members and forms an electrical heating unit. Upon start-up, this unit is connected to a current source for heating the air fed to the combustion chamber and downstream parts of the plant.