Abstract: A method of attaching tubes of high-qualilty material, such as titanium, stainless steel, etc., in a tube plate of a simpler material which is not wherein or substantially not weldable to the tube material, involves attaching sleeves of the same material or substantially the same material as the tubes, to the tubes so that the sleeves extend somewhat beyond the tube plates, whereafter a cover plate, provided with holes therein and being of the same or substantially the same material as the sleeves, is attached to the sleeves ends by means of welding.

Abstract: The invention relates to a method of operating a gas turbine unit comprising a combustion chamber, a high pressure turbine driven by gas from the combustion chamber, and a low pressure turbine driven by gas from the high pressure turbine, means for controlling the gas supply from the high pressure turbine to the low pressure turbine, and a low pressure compressor driven by the low pressure turbine, and a high pressure compressor connected in series with the low pressure compressor and driven by the high pressure turbine for supplying pressurized air to the combustion chamber, the useful power of the gas turbine unit being adjustable by controlling the gas condition upstream of the low pressure turbine by the control means. Substantially all the air delivered to the combustion chamber from the compressors, is utilized for the combustion in the combustion chamber.

Abstract: Method in combusting solid fuel in a first fluidized bed (11) and a second fluidized bed (12) located laterally of the first bed, said beds being mutually separated but communicating with each other. Fuel particles are transferred from the first bed to the second bed. The first bed is operated substoichiometrically and the second bed is operated with a large excess of air. Flue gas from the first bed is diverted in a common freeboard over the beds to be directed in counterflow towards the flue gas from the second bed. Heat power is recovered solely from the second bed.

Abstract: Method of manufacturing metal products from a powder (19) which is received in a mould cavity formed by a gas-tight casing (10, 11, 12, 13) and is isostatically hot pressed in the casing to form a monolithic body. A body (14) of graphite, hexagonal boron nitride, or another similar ceramic material is provided as a core in the mould cavity, and after the isostatic hot pressing this core is removed from the produced monolithic body by blasting.

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: Method in producing a molding of an iron alloy, wherein the molding is produced by hot isostat pressing of a prealloyed powder comprising 0.5 to 2.8% coal by weight, 24 to 35% chromium by weight, from effective amount to 2% silicon by weight, from effective amount to 1.5% manganese by weight, 0 to 2.3% nickel weight, and 0 to 3.0% molybdenum by weight, and the residue iron.

Abstract: A power plant with combustion of a fuel in fluidized bed (21) of particulate material, usually contains a sulphur absorbent. A bottom (14) divides a bed vessel (12) into an upper combustion chamber (15) and a lower conical or pyramid-shaped ash discharge chamber (16) for discharging ashes and consumed bed material. The bottom (14) is formed with openings (22) through which material is able to pass. Cooling air is supplied to the lower part of the lower chamber (16). This chamber (16) is provided with grates (37, 38) with horizontal channels (46) for spreading cooling air from the central part of the chamber (16) to its outer parts. These grates (37, 38) may be formed of U-sections with their openings facing downwards. The channels (46) of a grate (37) may be connected to the combustion chamber (15) by vertical tubes (50).

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: Method of supplying ammonia gas to boilers having at least two fluidized beds one above the other for reducing the content of nitrogen oxides in the flue gas wherein the ammonia gas is intermixed with secondary air or tertiary air before said air intermixed with flue gas from the lower fluidized bed is supplied to the upper fluidized bed or the upper fluidized beds, respectively, for fluidization equally distributed over the area of the bed or beds, respectively.

Abstract: A pneumatic conveying system for conveying particulate material includes a connection chamber for changing the direction of flow so as to bring about a pressure drop. An upstream tube and a downstream tube are connected, spaced from each other, to an end wall in the connection chamber. Between the tubes, the end wall is formed with a double-curved surface bulging inwards towards the connection chamber, said surface being suitably saddle-shaped.

Abstract: A power plant with a combustion chamber, in which fuel is burnt in a fluidized bed of a particulate material. The walls of the combustion chamber are provided on their inner side with a layer of a heat insulating material. Channel-section members are arranged between fixing means with the flanges of the channel-section members directed inwards towards the combustion chamber space. Plates cover openings which are formed between the channel-section members. These cover plates are provided with flanges passing in between the flanges of the channel-section members. The cover plates are held in position by fixing members and elements which connect the fixing members to the combustion chamber wall.

Abstract: A plant for combustion of a particulate fuel in a fluidized bed in a combustion chamber has the fuel supplied into the bottom of the combustion chamber by means of a pneumatic transportation system via nozzles. Fuel for the plurality of nozzles is transported through a duct to a distributor and from there via individual conduits to the nozzles of the combustion chamber. These conduits include flow-inhibiting, pressure-drop generating means, by means of which a pressure drop is generated between the distributor and the combustion chamber. These pressure-drop inducing means influence the velocity of flow and hence the transport capacity of the transport gas so that a desired, normally uniform, distribution of fuel to the bed is secured.

Abstract: The invention relates to method and apparatus for the combustion of fluidal fuels. The fuel is dispersed in combustion air and, in order to improve the combustion rate and efficiency, is exposed to a high particle velocity of a sound produced by a low frequency sound generator. The frequency of the sound is determined by the sound generator, the maximum frequency being 30 Hz. A reciprocating movement of combustion air and fuel particles entrained therein is obtained. The sound generator is a quarter wave type sound generator with a tubular resonator forming a diffuser at the open end thereof.

Abstract: The conveying properties of a particulate fuel during pneumatic transportation to a fluidized bed in a combustion plant, are improved by at least surface drying of the fuel. A calcium-containing bed material is withdrawn from the bed under such conditions that the bed material is calcined to form CaO. This withdrawn bed material is crushed and mixed with fuel, whereby the CaO absorbs water from the fuel in an exothermic reaction forming calcium hydroxide, Ca(OH).sub.2, the released heat evaporating moisture from the fuel. The fuel particles will have reduced surface moisture which reduces the risk of clogging during pneumatic feeding of fuel to a combustion chamber. Due to the intimate contact between the fuel particles and the crushed bed material, the tendency towards reaction between sulfer in the fuel and the bed material increases.

Abstract: A pneumatic transportation system for particulate material, such as powdered or granular materials, with a switching valve (7) for selection of different transport paths within the transportation system. The valve includes a turnable rotor (15) with a bore or a compartment (23), the inner part of which constitutes a blind space for forming an erosion-preventing cushion (26) of powder. An upstream conduit (6) is connected to the valve housing (14) opposite to the blind space of the compartment (23). In dependence on the position of the rotor (15), the compartment (23) or a channel (24) adjacent to this forms a connection to any one of several downstream conduits (20, 21) connected to the valve housing (14).

Abstract: A boiler plant with a multi-fluidized-bed combustion chamber comprising a first bed in a lower combustion space and a second bed in an upper combustion space and with nozzles in the support means for the beds for injection of combustion air into the first bed and combustion gases into the second bed for fluidization of the bed material therein. The plant is equipped with bed material transport devices for transferring bed material from the lower combustion chamber to the upper combustion chamber or vice versa. Further, measuring means is provided for measuring the temperature and depth of the lower bed, and signal processing and control means are provided for adapting the depth of the lower bed in dependence on plant load and bed temperature.

Abstract: The separating efficiency of a cyclone separator used for removing solid particles from a gas stream (for example ash particles from the combustion gas which is passed to a gas turbine) is increased by retarding the particles before they arrive at the cyclone and thereafter accelerating them over a short distance before they enter the cyclone. In this way large particles will have a lower speed than small particles when entering the cyclone. Despite a high velocity of the transport gas and a high inlet velocity for small particles, it is possible to obtain an inlet velocity for larger particles which is desirably low from the point of view of reducing erosion of the cyclone separator. The separation of fine particles is improved. The retardation of the particles may take place in a T-shaped branch pipe, which has one branch connected to the cyclone, a second branch connected to a conveying pipe and a third branch which is formed as a blind space.

Abstract: The invention relates to method and apparatus for the combustion of large solid fuels. In order to improve the beneficial effect of sound on combustion are a bed of the fuel located on a grate, the bed of fuel is exposed to a high particle velocity of a sound positively produced by an external low frequency sound generator, the frequency of which is determined by the sound generator, to provide a reciprocating movement of combustion air and combustion gas through the fuel bed. The dimensions of the grate in a plane transverse to the reciprocating movement of combustion air and combustion gas are less than a quarter of the wave length of the sound generated by the sound generator.

Abstract: A nozzle cap for a gas inlet fluidizing nozzle in the bottom plate of a post-combustion bed in a hot water or steam boiler with at least two fluidized beds is provided. Flue gases from an underlying combustion bed enter the post-combustion bed via a plurality of such gas inlet nozzles. Each nozzle cap is formed as a deflecting member for guiding the flue gases to the bed material and is shaped to minimize the risk of clogging of the cap with particles entrained in the flue gases and the risk of the cap being eroded by the fastly moving particles.

Abstract: The invention relates to a method of igniting, upon start-up, a combustion chamber (8) in a power plant with combustion of fuel in a fluidized bed (14). The air flow through the nozzles (13) of the combustion chamber bottom (12) for fluidization of the bed (14) and for combustion of the fuel can be reduced upon start-up; bed material, which is heated to the ignition temperature of a start-up fuel, is transferred from a storage container (40) to the combustion chamber (8), and fuel is supplied to the bed (14). In those cases where the air flow has been reduced during the transfer of the bed material, it is increased again when the fuel is supplied. The invention also relates to a power plant having means for temporarily bypassing the nozzles (13) of the combustion chamber bottom (12) while transferring hot bed material from a storage container (40) to the combustion chamber (8), and a fuel system (30-38) for the supply of fuel to the combustion chamber (8).