Abstract: Fluidizing apparatus comprises a grid defining cavities and main fluidizing gas blower channels connected to these cavities. Complementary channels pass through openings in swellings at the intersections of the cavities. Their upper ends are above the level of the grid. They are adapted to blow a complementary gas into an active area disposed above each swelling. A heat exchanger is adapted to exchange heat with the fluidized bed. It comprises at least one tube shaped so as to extend over the grid and through a plurality of these active areas. The rate of heat exchange may be modified by altering the complementary gas flowrate, without modifying the fluidization velocity.

Abstract: Method and a device for controlling the temperature of a reaction carried out within a vessel in a fluidized bed containing solid particles which can be entrained with the smoke and then recovered in a separating device and recycled into the fluidized bed after passage through a heat exchanger where they yield up their heat. The flow of particles separated from the smoke is divided into two parts, a hot part recycled directly into the fluidized bed and a cool part constituted by particles taken up at the outlet of the separating device and passed into the heat exchanger to constitute a reserve of cold material which can be mixed with the hot part before reinjection into the fluidized bed, the relative flow rates of the hot particles and of the cold particles being regulated so as to control the flow-rate and the average temperature of the flow of particles recycled into the fluidized bed for maintaining at the desired level the reaction temperature in the midst of the latter.

Abstract: Process and apparatus for supplying combustible material to a fluidized bed in a vessel connected to a separating device for the solid particles entrained with the smoke and containing a certain proportion of unburnt matter, the particles recovered being recycled into the fluidized bed. During a normal operation of the fluidized bed supplied with combustible matter, the solid particles recovered in the separating device are accumulated in a silo and periodically, the supply of combustible matter is stopped and the particles accumulated in the silo are recycled into the fluidized bed with a regulated flow rate, so that the combustion of the unburnt matter contained in the recycled particles maintains the temperature of the fluidized bed at the desired level. The exothermic reaction is maintained alternately by the combustion of the combustible matter in the normal operating phase and by the combustion of the unburnt matter in the recycling phase.

Abstract: Method and apparatus for regulating the heat transfer coefficient between a granular material and an exchange surface inside a heat exchanger in which a descending flow of a charge of material is arranged in the form of a mobile bed in contact with an elongated exchange member extending between lower and upper levels of the tank of the exchanger. The latter is provided with injection means for a gas into the charge of material. The flow conditions of the gas passing through the charge from below upwards are regulated so that the ascending flow speed is initially less than, at the base of the tank, the critical fluidization speed and then increases gradually to reach such critical speed at an adjustable level comprised between the lower and upper levels of the exchange member. The invention is especially applicable to heat exchangers used for cooling a granular material and/or for the heating of a heat transfer fluid.

Abstract: The invention relates to a recovery method and installation for the heat contained in a solid substance, occurring in divided form and more especially in ash produced by a fluidized bed combustion furnace. According to the invention the coarsest ash is removed through a purging outlet from the fluidized bed, the finest ash is separated from the smoke and the ash is cooled in two apparatuses adapted to the granulometry, one to the finest ash and the other to the coarsest ash.

Abstract: Method for supplying fuel material to a gasification reactor into which a mixture of finely powdered fuel material, in suspension in a liquid phase, is charged inside a pressurized combustion chamber into which the combustion-supporting gas is injected and constituting the reactor, by means of a screw conveyor producing a continuously fluid-tight plug by compression of the driven material. By intermeshing at least two overlapping screws with identical threads rotated in the same direction, a wringing of the mixture introduced through an input orifice is compressed by regulating the flow rate of the mixture supply and the rotary speed of the screws so that, for a given flow rate of material, the plug constituted in a braking zone is at a given pressure and contains a certain proportion of liquid phase. The additional amount of liquid phase is expelled into the braking zone and reascends upstream into a drive zone where it is removed through orifices formed in filtering parts of a sleeve.

Abstract: The process comprises oxidation of alkali-metal-containing carbonaceous products at a temperature of at least 800.degree. C. in a fluidized bed of fire-proof particles capable of trapping or fixing the metal elements.