Abstract: The device for feeding fluidizing gas to the openings (1) in a fluidizing grid (2) comprises an end piece (4) fitted on each bottom inlet (3) to each opening (1) and having a length e lying in the range between 0 and 0.5 times the diameter d of the end piece, and a cup (5a) into which the end piece extends, with the bottom (6) of the cup being at a distance i from the end piece, which distance may optionally be adjustable. The entire device is housed in a fluidizing gas feed box (5).

Abstract: Fluidized bed apparatus comprises a perforated grid to which fluidizing gas is fed by way of a plurality of tubes to fluidize particles supported on the grid. Each tube is connected to a respective blow opening of the grid by way of an erect tubular end part.Apparatus for supplying the openings of the grid with unclogging gas comprises a plurality of injection tubes, each arranged to extend within a corresponding tubular end part. Each injection tube has a number of lateral orifices for the passage of the unclogging gas to be supplied to the injection tube.The unclogging gas is used to disaggregate any particles accumulating in said tubular end part during stoppages in operation of the bed.

Abstract: A vertical conduit closed at one end by a head wall and connected at its opposite end to a fluidization gas delivery means is provided with side blowing nozzles longitudinally spaced in planes. A shutter is movable inside the conduit so that the bed in which the conduit is disposed in use can be progressively brought into a state of fluidization by supplying fluidization gas to the nozzles successively and cumulatively starting from the top. The invention obviates the need for the introduction via the bottom of the fluidized bed of compressed air at a high pressure when starting up the fluidization of the bed.