Abstract: A heat exchanger system includes a first heat exchanger followed by a second heat exchanger disposed in a dense fluidized bed, the second heat exchanger being made up of a plurality of nests of tubes disposed along the path of the particles in suspension in the dense fluidized bed. The second heat exchanger is provided with at least two feeds situated on either side of its center, each of the feeds receives a distinct mixture of the input fluid and of the output fluid of the first heat exchanger, so that the temperature of the fluid fed into each of the nests is an increasing function of the distance between it and the inlet via which the particles are fed into the dense fluidized bed.

Abstract: The method consists in causing the flue gases to pass through a filter placed inside the recovery boiler so that the fly ash contained in said flue gases can be hot filtered out. An additional flow (B) of a material is superposed on the flow of fly ash to be filtered, which material has characteristics such that it increases the melting point of the fly ash by forming high melting point eutectics so as to facilitate unclogging by preventing viscous bridges from forming between the particles of fly ash. Application to hot scrubbing of flue gases generated by burning household refuse.

Abstract: A refuse recycling system which recycles municipal waste as energy, includes a shredder for shredding the waste and removing rejects via a feed pipe to a circulating fluidized bed reactor, the reactor producing flue gases. The reactor includes a side dense fluidized bed situated on the wall of the reactor which is provided with the feed pipe, the side dense fluidized bed extracting non-fluidizable heavy elements and transporting them to a coarse-particle sorter apparatus via an extraction duct disposed at a base of the side dense fluidized bed. At least a portion of the rejects from the shredder is fed into the coarse-particle sorter apparatus. The coarse-particle sorter apparatus cools the elements and extracts non-fluidizable inert matter from the elements, the remaining matter being fed back into the reactor. A module for recovering energy and for treating the flue gases output by said reactor is connected downstream from the reactor.

Abstract: A boiler comprising a circulating fluidized bed hearth, a separator member for separating flue gas and solids extracted from the hearth, an external dense fluidized bed between the solids outlet of the separator member and the base of the hearth, the external bed containing a first heat exchanger in which a coolant fluid to be evaporated circulates. The outlet of the first heat exchanger is connected to a second heat exchanger placed in the hearth.

Abstract: An apparatus for recycling municipal waste as energy includes a shredder for shredding the waste, and removing rejects, the rejects from the shredder being sorted into a first stream of inert matter that is substantially unpolluted with organic matter and into a second stream of inert matter that is substantially polluted with either organic matter or with combustible heavy elements; a first outlet for removing the second stream of inert matter; a circulating fluidized bed reactor for receiving the shredded waste and producing gases with solid particles therein; a cyclone for separating out the solid particles and receiving the gases output by the reactor; a recuperator boiler into which the gases output by the cyclone are discharged and which is provided with a first set of heat exchangers, the boiler including a dust-filtering hopper; a second outlet for removing the solid particles from the dust-filtering hopper; a second set of heat exchangers disposed in a chamber into which the gases are fed after trans

Abstract: A device for continuously measuring the quantity of coal inside a ball grinder including an ultrasound wave or electromagnetic wave emitter and a wave receiver. The emitter and the receiver are disposed so that the wave passes through at least part of the interior of the grinder. The receiver is associated with an electronic circuit for deducing the quantity of coal by comparing the signal received with data obtained from previous calibration measurements.

Abstract: A dense fluidized bed exchanger includes a casing the vertical longitudinal walls of which consist of tubes conveying a heat-conducting fluid, the casing being divided lengthwise into chambers separated from each other by a baffle consisting of a wall consisting of tubes conveying a heat-conducting fluid. The vertical longitudinal walls consist of horizontal tubes and the baffle extends from the bottom wall of the casing to a height less than that of the latter and consists of superposed hairpin-shape transverse extensions of tubes of each of the vertical longitudinal walls disposed perpendicular to the tubes and extending to the opposite vertical longitudinal wall.

Abstract: A fluidized bed reactor includes an axial recirculating fluidized bed and at least first and second lateral dense fluidized beds, respectively disposed along a first and a second wall of the jacket of the reactor. Waste is fed via at least one point on the first wall of the jacket of the reactor, above the first lateral dense fluidized bed. The reactor includes at least one duct for extracting non-fluidizable heavy elements at the base of the first lateral dense fluidized bed.

Abstract: The invention concerns a device adapted to be fixed and sealed to at least one cylindrical member (1, 1'), characterized in that it includes:a first sleeve (2),a second sleeve (3) coaxial with the first sleeve (2) having a greater capacity for deformation than the first sleeve (2) and fixed and sealed to the first sleeve (2) at both ends,at least two cylindrical rings (4, 5) coaxial with the second sleeve (3), pressed against the latter and each fixed by one edge to one end of the second sleeve (3), andmeans (6, 6') for injecting a pressurized fluid between the first sleeve (2) and the second sleeve (3).

Abstract: The present invention relates to a ball mill having a substantially horizontal axis of rotation and including a drum supported by two trunions having the same axis of rotation and situated at respective ends of the drum, raw coal being conveyed by substantially vertical pipework to the vicinity of a cylinder having the same axis of rotation and disposed within each trunion so as to open out into the drum, with the space lying between each trunion and its cylinder being connected to a pulverized coal outlet duct via a separator. A raw coal guide member is disposed beneath the pipework, conveying coal under gravity into the inside of the cylinder which includes a rigid Archimedes' screw on its inside surface, a main air feed being provided on said pipework upstream from the separator, all of said air being channeled towards the inside of the cylinder.

Abstract: The heat exchanger comprises at least one first sheet tubes and at least one second sheet of tubes, the sheets being suspended in a case. The two sheets are juxtaposed in a vertical plane, the first sheet of tubes connecting a first inlet fluid manifold disposed at the bottom and on one side of a case to an outlet manifold disposed in a central top portion of the case, and the second sheet of tubes connecting a second inlet fluid manifold disposed at the bottom and on one side of the case to the outlet manifold. Each sheet comprises first tubes which extend horizontally in the bottom portion of the case, second tubes which are connected to the first tubes and which extend vertically between the bottom portion of the case and the middle portion of the case, and bent third tubes which are connected to the second tubes and which extend between the middle portion of the case and the top portion of the case. This configuration makes it possible to obtain a large heat exchange area with a compact heat exchanger.

Abstract: A circulating fluidized bed reactor comprising a top zone surrounded by walls provided with heat exchange tubes, the heat exchange tubes being interconnected by fins, and a bottom zone provided with a fluidization grid, a primary air injection device beneath the grid, a secondary air injection device above the grid, and a fuel injection device, the walls surrounding the bottom zone being provided with heat exchange tubes. The walls of the zones are provided with vertical heat exchange panels referred to as "extensions" that extend perpendicularly to the walls of the zones, that are made up of tubes inside the reactor, that are of horizontal width lying in the range 150 mm to 500 mm, and that are spaced apart from one another via a distance lying in the range 1.5 times to 4 times their width, the width being defined as the distance between the inside faces of the fins of the walls and the most distant generator lines of the most distant tubes of the extensions.

Abstract: A monitoring device for continuously monitoring the internal circulation flow-rate of solid particles in a circulating fluidized bed reactor including a bottom zone into which the fluidization gas is injected and a top zone surrounded by walls. The device includes a sampling tank for sampling internal circulation of solids, which tank is fixed against one of the walls of the reactor and is provided with a fluidization device. A removal pipe is provided for removing the solids from the tank and conveying them to a measuring device for measuring the flow-rate of the solids. A return pipe is provided for returning the solids from the measuring device to the inside of the reactor.

Abstract: The present invention concerns a device for monitoring a ball grinder having a cylindrical casing containing a mass of balls which, when the grinder is rotating at its nominal speed, takes up a position between two generatrices (1.sub.b, 1.sub.b') spaced by an angle between a minimal angle .alpha..sub.min and a maximal angle .alpha..sub.max and a mass of coal which, when the grinder is rotating at its nominal speed, takes up a position between two generatrices (1.sub.c, 1.sub.c') spaced by an angle .beta.. An electromagnetic wave emitter is disposed inside the grinder and at least one wave receiver is disposed outside the grinder. The receiver is associated with an electronic circuit for determining at least one parameter of the grinder selected from the quantity of balls, the quantity of coal and the wear of the cylinder.

Abstract: The present invention relates to a rack for holding a set of tubes, in particular for forming a heat exchanger, each of the tubes making up the set being provided with a helical outer fin, and said tubes being disposed in n rows of p tubes, the rack including transverse holding section members disposed between each row and longitudinal holding lugs engaged in gaps between the turns of the fins on the corresponding tubes. Bars that are perpendicular to said transverse holding section members separate the p adjacent tubes in each of the n rows, the transverse holding section members being threaded through n-1 orifices provided in the bars, said bars and said section members forming a holding mesh. The longitudinal holding lugs are constituted by separate brackets, each of which includes an engageable lug and at least one fastening tab for fastening it to said mesh.

Abstract: A method of treating solid residue resulting from combustion of a sulfur-containing fuel in the hearth of a boiler having a circulating fluidized bed, in which method limestone is inserted into the hearth so as to make it possible to absorb the resulting sulfur dioxide in the form of calcium sulfate CaSO.sub.4, the method further including the following steps:1) prior to being inserted into the hearth, the fuel is ground down to less than 100 microns;2) prior to being inserted into the hearth, the limestone is ground down to a grain-size centered in the range 100 microns to 150 microns, with a maximum of 1 mm;3) at the base of the hearth, the combustion residue is collected, which residue includes lime and calcium sulfate resulting from taking up the sulfur dioxide SO.sub.2 evolved by the combustion, and the residue is subjected to heat treatment in a reactor, in which both solid matter based on lime CaO, and also a gaseous mixture containing, in particular, sulfur dioxide SO.sub.

Abstract: A monitoring device for continuously monitoring the internal circulation flow-rate of solid particles in a circulating fluidized bed reactor including a bottom zone into which the fluidization gas is injected, and a top zone surrounded by walls. The device includes a sampling tank for sampling internal circulation solids, which tank is fixed against one of the walls of the reactor and is provided with a fluidization device. A removal pipe is provided for removing the solids from the tank and conveying them to a measuring device for measuring the flow-rate of the solids. A return pipe is provided for returning the solids from the measuring device to the inside of the reactor.

Abstract: An expansion joint connecting the ends of two pipes adapted to convey a hot fluid, each end having an end flange, includes a sleeve fastened at its respective edges to a cold flange fastened to a nesting device and a coupling arrangement connecting the end flange and the corresponding cold flange. The coupling arrangement comprises at least two members connected together, one fastened to the cold flange and the other fastened to the end flange. A first member is a corrugated sheetmetal sleeve the undulations of which are parallel to the longitudinal direction of the pipe and a second member is flexible and deformable in the longitudinal direction of the pipe.

Abstract: A fluidized bed hearth floor comprises a supporting metal sheet provided with fluidization-gas injection nozzles. The supporting sheet is made of refractory metal, and is covered with a plurality of flat elements made of refractory metal, each flat element being fixed to the supporting sheet by welding in a localized zone, e.g., substantially at a point.

Abstract: The present invention relates to a fastening system for fastening a through pipe to a hearth wall, the pipe opening into a box. The fastening system comprises external pipe-securing means for securing the pipe to said screen, and an internal metal guide tube fitted over said pipe and having one of its ends interposed between said pipe and the orifice through which said pipe passes, its other end being externally threaded. The guide tube carries a rigid washer which is disposed so as to abut against the inside face of the inside layer, and against which a wall of the box is mounted, which wall is provided with an orifice that is larger than the cross-section of the guide tube, a sealing device being clamped against the wall of the box by a nut screwed onto the threaded end of the guide tube.